v4.19.13 snapshot.
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
new file mode 100644
index 0000000..0f67197
--- /dev/null
+++ b/drivers/tty/serial/imx.c
@@ -0,0 +1,2570 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Driver for Motorola/Freescale IMX serial ports
+ *
+ * Based on drivers/char/serial.c, by Linus Torvalds, Theodore Ts'o.
+ *
+ * Author: Sascha Hauer <sascha@saschahauer.de>
+ * Copyright (C) 2004 Pengutronix
+ */
+
+#if defined(CONFIG_SERIAL_IMX_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
+#define SUPPORT_SYSRQ
+#endif
+
+#include <linux/module.h>
+#include <linux/ioport.h>
+#include <linux/init.h>
+#include <linux/console.h>
+#include <linux/sysrq.h>
+#include <linux/platform_device.h>
+#include <linux/tty.h>
+#include <linux/tty_flip.h>
+#include <linux/serial_core.h>
+#include <linux/serial.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/rational.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/io.h>
+#include <linux/dma-mapping.h>
+
+#include <asm/irq.h>
+#include <linux/platform_data/serial-imx.h>
+#include <linux/platform_data/dma-imx.h>
+
+#include "serial_mctrl_gpio.h"
+
+/* Register definitions */
+#define URXD0 0x0 /* Receiver Register */
+#define URTX0 0x40 /* Transmitter Register */
+#define UCR1 0x80 /* Control Register 1 */
+#define UCR2 0x84 /* Control Register 2 */
+#define UCR3 0x88 /* Control Register 3 */
+#define UCR4 0x8c /* Control Register 4 */
+#define UFCR 0x90 /* FIFO Control Register */
+#define USR1 0x94 /* Status Register 1 */
+#define USR2 0x98 /* Status Register 2 */
+#define UESC 0x9c /* Escape Character Register */
+#define UTIM 0xa0 /* Escape Timer Register */
+#define UBIR 0xa4 /* BRM Incremental Register */
+#define UBMR 0xa8 /* BRM Modulator Register */
+#define UBRC 0xac /* Baud Rate Count Register */
+#define IMX21_ONEMS 0xb0 /* One Millisecond register */
+#define IMX1_UTS 0xd0 /* UART Test Register on i.mx1 */
+#define IMX21_UTS 0xb4 /* UART Test Register on all other i.mx*/
+
+/* UART Control Register Bit Fields.*/
+#define URXD_DUMMY_READ (1<<16)
+#define URXD_CHARRDY (1<<15)
+#define URXD_ERR (1<<14)
+#define URXD_OVRRUN (1<<13)
+#define URXD_FRMERR (1<<12)
+#define URXD_BRK (1<<11)
+#define URXD_PRERR (1<<10)
+#define URXD_RX_DATA (0xFF<<0)
+#define UCR1_ADEN (1<<15) /* Auto detect interrupt */
+#define UCR1_ADBR (1<<14) /* Auto detect baud rate */
+#define UCR1_TRDYEN (1<<13) /* Transmitter ready interrupt enable */
+#define UCR1_IDEN (1<<12) /* Idle condition interrupt */
+#define UCR1_ICD_REG(x) (((x) & 3) << 10) /* idle condition detect */
+#define UCR1_RRDYEN (1<<9) /* Recv ready interrupt enable */
+#define UCR1_RXDMAEN (1<<8) /* Recv ready DMA enable */
+#define UCR1_IREN (1<<7) /* Infrared interface enable */
+#define UCR1_TXMPTYEN (1<<6) /* Transimitter empty interrupt enable */
+#define UCR1_RTSDEN (1<<5) /* RTS delta interrupt enable */
+#define UCR1_SNDBRK (1<<4) /* Send break */
+#define UCR1_TXDMAEN (1<<3) /* Transmitter ready DMA enable */
+#define IMX1_UCR1_UARTCLKEN (1<<2) /* UART clock enabled, i.mx1 only */
+#define UCR1_ATDMAEN (1<<2) /* Aging DMA Timer Enable */
+#define UCR1_DOZE (1<<1) /* Doze */
+#define UCR1_UARTEN (1<<0) /* UART enabled */
+#define UCR2_ESCI (1<<15) /* Escape seq interrupt enable */
+#define UCR2_IRTS (1<<14) /* Ignore RTS pin */
+#define UCR2_CTSC (1<<13) /* CTS pin control */
+#define UCR2_CTS (1<<12) /* Clear to send */
+#define UCR2_ESCEN (1<<11) /* Escape enable */
+#define UCR2_PREN (1<<8) /* Parity enable */
+#define UCR2_PROE (1<<7) /* Parity odd/even */
+#define UCR2_STPB (1<<6) /* Stop */
+#define UCR2_WS (1<<5) /* Word size */
+#define UCR2_RTSEN (1<<4) /* Request to send interrupt enable */
+#define UCR2_ATEN (1<<3) /* Aging Timer Enable */
+#define UCR2_TXEN (1<<2) /* Transmitter enabled */
+#define UCR2_RXEN (1<<1) /* Receiver enabled */
+#define UCR2_SRST (1<<0) /* SW reset */
+#define UCR3_DTREN (1<<13) /* DTR interrupt enable */
+#define UCR3_PARERREN (1<<12) /* Parity enable */
+#define UCR3_FRAERREN (1<<11) /* Frame error interrupt enable */
+#define UCR3_DSR (1<<10) /* Data set ready */
+#define UCR3_DCD (1<<9) /* Data carrier detect */
+#define UCR3_RI (1<<8) /* Ring indicator */
+#define UCR3_ADNIMP (1<<7) /* Autobaud Detection Not Improved */
+#define UCR3_RXDSEN (1<<6) /* Receive status interrupt enable */
+#define UCR3_AIRINTEN (1<<5) /* Async IR wake interrupt enable */
+#define UCR3_AWAKEN (1<<4) /* Async wake interrupt enable */
+#define UCR3_DTRDEN (1<<3) /* Data Terminal Ready Delta Enable. */
+#define IMX21_UCR3_RXDMUXSEL (1<<2) /* RXD Muxed Input Select */
+#define UCR3_INVT (1<<1) /* Inverted Infrared transmission */
+#define UCR3_BPEN (1<<0) /* Preset registers enable */
+#define UCR4_CTSTL_SHF 10 /* CTS trigger level shift */
+#define UCR4_CTSTL_MASK 0x3F /* CTS trigger is 6 bits wide */
+#define UCR4_INVR (1<<9) /* Inverted infrared reception */
+#define UCR4_ENIRI (1<<8) /* Serial infrared interrupt enable */
+#define UCR4_WKEN (1<<7) /* Wake interrupt enable */
+#define UCR4_REF16 (1<<6) /* Ref freq 16 MHz */
+#define UCR4_IDDMAEN (1<<6) /* DMA IDLE Condition Detected */
+#define UCR4_IRSC (1<<5) /* IR special case */
+#define UCR4_TCEN (1<<3) /* Transmit complete interrupt enable */
+#define UCR4_BKEN (1<<2) /* Break condition interrupt enable */
+#define UCR4_OREN (1<<1) /* Receiver overrun interrupt enable */
+#define UCR4_DREN (1<<0) /* Recv data ready interrupt enable */
+#define UFCR_RXTL_SHF 0 /* Receiver trigger level shift */
+#define UFCR_DCEDTE (1<<6) /* DCE/DTE mode select */
+#define UFCR_RFDIV (7<<7) /* Reference freq divider mask */
+#define UFCR_RFDIV_REG(x) (((x) < 7 ? 6 - (x) : 6) << 7)
+#define UFCR_TXTL_SHF 10 /* Transmitter trigger level shift */
+#define USR1_PARITYERR (1<<15) /* Parity error interrupt flag */
+#define USR1_RTSS (1<<14) /* RTS pin status */
+#define USR1_TRDY (1<<13) /* Transmitter ready interrupt/dma flag */
+#define USR1_RTSD (1<<12) /* RTS delta */
+#define USR1_ESCF (1<<11) /* Escape seq interrupt flag */
+#define USR1_FRAMERR (1<<10) /* Frame error interrupt flag */
+#define USR1_RRDY (1<<9) /* Receiver ready interrupt/dma flag */
+#define USR1_AGTIM (1<<8) /* Ageing timer interrupt flag */
+#define USR1_DTRD (1<<7) /* DTR Delta */
+#define USR1_RXDS (1<<6) /* Receiver idle interrupt flag */
+#define USR1_AIRINT (1<<5) /* Async IR wake interrupt flag */
+#define USR1_AWAKE (1<<4) /* Aysnc wake interrupt flag */
+#define USR2_ADET (1<<15) /* Auto baud rate detect complete */
+#define USR2_TXFE (1<<14) /* Transmit buffer FIFO empty */
+#define USR2_DTRF (1<<13) /* DTR edge interrupt flag */
+#define USR2_IDLE (1<<12) /* Idle condition */
+#define USR2_RIDELT (1<<10) /* Ring Interrupt Delta */
+#define USR2_RIIN (1<<9) /* Ring Indicator Input */
+#define USR2_IRINT (1<<8) /* Serial infrared interrupt flag */
+#define USR2_WAKE (1<<7) /* Wake */
+#define USR2_DCDIN (1<<5) /* Data Carrier Detect Input */
+#define USR2_RTSF (1<<4) /* RTS edge interrupt flag */
+#define USR2_TXDC (1<<3) /* Transmitter complete */
+#define USR2_BRCD (1<<2) /* Break condition */
+#define USR2_ORE (1<<1) /* Overrun error */
+#define USR2_RDR (1<<0) /* Recv data ready */
+#define UTS_FRCPERR (1<<13) /* Force parity error */
+#define UTS_LOOP (1<<12) /* Loop tx and rx */
+#define UTS_TXEMPTY (1<<6) /* TxFIFO empty */
+#define UTS_RXEMPTY (1<<5) /* RxFIFO empty */
+#define UTS_TXFULL (1<<4) /* TxFIFO full */
+#define UTS_RXFULL (1<<3) /* RxFIFO full */
+#define UTS_SOFTRST (1<<0) /* Software reset */
+
+/* We've been assigned a range on the "Low-density serial ports" major */
+#define SERIAL_IMX_MAJOR 207
+#define MINOR_START 16
+#define DEV_NAME "ttymxc"
+
+/*
+ * This determines how often we check the modem status signals
+ * for any change. They generally aren't connected to an IRQ
+ * so we have to poll them. We also check immediately before
+ * filling the TX fifo incase CTS has been dropped.
+ */
+#define MCTRL_TIMEOUT (250*HZ/1000)
+
+#define DRIVER_NAME "IMX-uart"
+
+#define UART_NR 8
+
+/* i.MX21 type uart runs on all i.mx except i.MX1 and i.MX6q */
+enum imx_uart_type {
+ IMX1_UART,
+ IMX21_UART,
+ IMX53_UART,
+ IMX6Q_UART,
+};
+
+/* device type dependent stuff */
+struct imx_uart_data {
+ unsigned uts_reg;
+ enum imx_uart_type devtype;
+};
+
+struct imx_port {
+ struct uart_port port;
+ struct timer_list timer;
+ unsigned int old_status;
+ unsigned int have_rtscts:1;
+ unsigned int have_rtsgpio:1;
+ unsigned int dte_mode:1;
+ struct clk *clk_ipg;
+ struct clk *clk_per;
+ const struct imx_uart_data *devdata;
+
+ struct mctrl_gpios *gpios;
+
+ /* shadow registers */
+ unsigned int ucr1;
+ unsigned int ucr2;
+ unsigned int ucr3;
+ unsigned int ucr4;
+ unsigned int ufcr;
+
+ /* DMA fields */
+ unsigned int dma_is_enabled:1;
+ unsigned int dma_is_rxing:1;
+ unsigned int dma_is_txing:1;
+ struct dma_chan *dma_chan_rx, *dma_chan_tx;
+ struct scatterlist rx_sgl, tx_sgl[2];
+ void *rx_buf;
+ struct circ_buf rx_ring;
+ unsigned int rx_periods;
+ dma_cookie_t rx_cookie;
+ unsigned int tx_bytes;
+ unsigned int dma_tx_nents;
+ unsigned int saved_reg[10];
+ bool context_saved;
+};
+
+struct imx_port_ucrs {
+ unsigned int ucr1;
+ unsigned int ucr2;
+ unsigned int ucr3;
+};
+
+static struct imx_uart_data imx_uart_devdata[] = {
+ [IMX1_UART] = {
+ .uts_reg = IMX1_UTS,
+ .devtype = IMX1_UART,
+ },
+ [IMX21_UART] = {
+ .uts_reg = IMX21_UTS,
+ .devtype = IMX21_UART,
+ },
+ [IMX53_UART] = {
+ .uts_reg = IMX21_UTS,
+ .devtype = IMX53_UART,
+ },
+ [IMX6Q_UART] = {
+ .uts_reg = IMX21_UTS,
+ .devtype = IMX6Q_UART,
+ },
+};
+
+static const struct platform_device_id imx_uart_devtype[] = {
+ {
+ .name = "imx1-uart",
+ .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX1_UART],
+ }, {
+ .name = "imx21-uart",
+ .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX21_UART],
+ }, {
+ .name = "imx53-uart",
+ .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX53_UART],
+ }, {
+ .name = "imx6q-uart",
+ .driver_data = (kernel_ulong_t) &imx_uart_devdata[IMX6Q_UART],
+ }, {
+ /* sentinel */
+ }
+};
+MODULE_DEVICE_TABLE(platform, imx_uart_devtype);
+
+static const struct of_device_id imx_uart_dt_ids[] = {
+ { .compatible = "fsl,imx6q-uart", .data = &imx_uart_devdata[IMX6Q_UART], },
+ { .compatible = "fsl,imx53-uart", .data = &imx_uart_devdata[IMX53_UART], },
+ { .compatible = "fsl,imx1-uart", .data = &imx_uart_devdata[IMX1_UART], },
+ { .compatible = "fsl,imx21-uart", .data = &imx_uart_devdata[IMX21_UART], },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, imx_uart_dt_ids);
+
+static void imx_uart_writel(struct imx_port *sport, u32 val, u32 offset)
+{
+ switch (offset) {
+ case UCR1:
+ sport->ucr1 = val;
+ break;
+ case UCR2:
+ sport->ucr2 = val;
+ break;
+ case UCR3:
+ sport->ucr3 = val;
+ break;
+ case UCR4:
+ sport->ucr4 = val;
+ break;
+ case UFCR:
+ sport->ufcr = val;
+ break;
+ default:
+ break;
+ }
+ writel(val, sport->port.membase + offset);
+}
+
+static u32 imx_uart_readl(struct imx_port *sport, u32 offset)
+{
+ switch (offset) {
+ case UCR1:
+ return sport->ucr1;
+ break;
+ case UCR2:
+ /*
+ * UCR2_SRST is the only bit in the cached registers that might
+ * differ from the value that was last written. As it only
+ * automatically becomes one after being cleared, reread
+ * conditionally.
+ */
+ if (!(sport->ucr2 & UCR2_SRST))
+ sport->ucr2 = readl(sport->port.membase + offset);
+ return sport->ucr2;
+ break;
+ case UCR3:
+ return sport->ucr3;
+ break;
+ case UCR4:
+ return sport->ucr4;
+ break;
+ case UFCR:
+ return sport->ufcr;
+ break;
+ default:
+ return readl(sport->port.membase + offset);
+ }
+}
+
+static inline unsigned imx_uart_uts_reg(struct imx_port *sport)
+{
+ return sport->devdata->uts_reg;
+}
+
+static inline int imx_uart_is_imx1(struct imx_port *sport)
+{
+ return sport->devdata->devtype == IMX1_UART;
+}
+
+static inline int imx_uart_is_imx21(struct imx_port *sport)
+{
+ return sport->devdata->devtype == IMX21_UART;
+}
+
+static inline int imx_uart_is_imx53(struct imx_port *sport)
+{
+ return sport->devdata->devtype == IMX53_UART;
+}
+
+static inline int imx_uart_is_imx6q(struct imx_port *sport)
+{
+ return sport->devdata->devtype == IMX6Q_UART;
+}
+/*
+ * Save and restore functions for UCR1, UCR2 and UCR3 registers
+ */
+#if defined(CONFIG_SERIAL_IMX_CONSOLE)
+static void imx_uart_ucrs_save(struct imx_port *sport,
+ struct imx_port_ucrs *ucr)
+{
+ /* save control registers */
+ ucr->ucr1 = imx_uart_readl(sport, UCR1);
+ ucr->ucr2 = imx_uart_readl(sport, UCR2);
+ ucr->ucr3 = imx_uart_readl(sport, UCR3);
+}
+
+static void imx_uart_ucrs_restore(struct imx_port *sport,
+ struct imx_port_ucrs *ucr)
+{
+ /* restore control registers */
+ imx_uart_writel(sport, ucr->ucr1, UCR1);
+ imx_uart_writel(sport, ucr->ucr2, UCR2);
+ imx_uart_writel(sport, ucr->ucr3, UCR3);
+}
+#endif
+
+static void imx_uart_rts_active(struct imx_port *sport, u32 *ucr2)
+{
+ *ucr2 &= ~(UCR2_CTSC | UCR2_CTS);
+
+ sport->port.mctrl |= TIOCM_RTS;
+ mctrl_gpio_set(sport->gpios, sport->port.mctrl);
+}
+
+static void imx_uart_rts_inactive(struct imx_port *sport, u32 *ucr2)
+{
+ *ucr2 &= ~UCR2_CTSC;
+ *ucr2 |= UCR2_CTS;
+
+ sport->port.mctrl &= ~TIOCM_RTS;
+ mctrl_gpio_set(sport->gpios, sport->port.mctrl);
+}
+
+static void imx_uart_rts_auto(struct imx_port *sport, u32 *ucr2)
+{
+ *ucr2 |= UCR2_CTSC;
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_start_rx(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ unsigned int ucr1, ucr2;
+
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr2 = imx_uart_readl(sport, UCR2);
+
+ ucr2 |= UCR2_RXEN;
+
+ if (sport->dma_is_enabled) {
+ ucr1 |= UCR1_RXDMAEN | UCR1_ATDMAEN;
+ } else {
+ ucr1 |= UCR1_RRDYEN;
+ ucr2 |= UCR2_ATEN;
+ }
+
+ /* Write UCR2 first as it includes RXEN */
+ imx_uart_writel(sport, ucr2, UCR2);
+ imx_uart_writel(sport, ucr1, UCR1);
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_stop_tx(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ u32 ucr1;
+
+ /*
+ * We are maybe in the SMP context, so if the DMA TX thread is running
+ * on other cpu, we have to wait for it to finish.
+ */
+ if (sport->dma_is_txing)
+ return;
+
+ ucr1 = imx_uart_readl(sport, UCR1);
+ imx_uart_writel(sport, ucr1 & ~UCR1_TXMPTYEN, UCR1);
+
+ /* in rs485 mode disable transmitter if shifter is empty */
+ if (port->rs485.flags & SER_RS485_ENABLED &&
+ imx_uart_readl(sport, USR2) & USR2_TXDC) {
+ u32 ucr2 = imx_uart_readl(sport, UCR2), ucr4;
+ if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
+ imx_uart_rts_active(sport, &ucr2);
+ else
+ imx_uart_rts_inactive(sport, &ucr2);
+ imx_uart_writel(sport, ucr2, UCR2);
+
+ imx_uart_start_rx(port);
+
+ ucr4 = imx_uart_readl(sport, UCR4);
+ ucr4 &= ~UCR4_TCEN;
+ imx_uart_writel(sport, ucr4, UCR4);
+ }
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_stop_rx(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ u32 ucr1, ucr2;
+
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr2 = imx_uart_readl(sport, UCR2);
+
+ if (sport->dma_is_enabled) {
+ ucr1 &= ~(UCR1_RXDMAEN | UCR1_ATDMAEN);
+ } else {
+ ucr1 &= ~UCR1_RRDYEN;
+ ucr2 &= ~UCR2_ATEN;
+ }
+ imx_uart_writel(sport, ucr1, UCR1);
+
+ ucr2 &= ~UCR2_RXEN;
+ imx_uart_writel(sport, ucr2, UCR2);
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_enable_ms(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+
+ mod_timer(&sport->timer, jiffies);
+
+ mctrl_gpio_enable_ms(sport->gpios);
+}
+
+static void imx_uart_dma_tx(struct imx_port *sport);
+
+/* called with port.lock taken and irqs off */
+static inline void imx_uart_transmit_buffer(struct imx_port *sport)
+{
+ struct circ_buf *xmit = &sport->port.state->xmit;
+
+ if (sport->port.x_char) {
+ /* Send next char */
+ imx_uart_writel(sport, sport->port.x_char, URTX0);
+ sport->port.icount.tx++;
+ sport->port.x_char = 0;
+ return;
+ }
+
+ if (uart_circ_empty(xmit) || uart_tx_stopped(&sport->port)) {
+ imx_uart_stop_tx(&sport->port);
+ return;
+ }
+
+ if (sport->dma_is_enabled) {
+ u32 ucr1;
+ /*
+ * We've just sent a X-char Ensure the TX DMA is enabled
+ * and the TX IRQ is disabled.
+ **/
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr1 &= ~UCR1_TXMPTYEN;
+ if (sport->dma_is_txing) {
+ ucr1 |= UCR1_TXDMAEN;
+ imx_uart_writel(sport, ucr1, UCR1);
+ } else {
+ imx_uart_writel(sport, ucr1, UCR1);
+ imx_uart_dma_tx(sport);
+ }
+
+ return;
+ }
+
+ while (!uart_circ_empty(xmit) &&
+ !(imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)) {
+ /* send xmit->buf[xmit->tail]
+ * out the port here */
+ imx_uart_writel(sport, xmit->buf[xmit->tail], URTX0);
+ xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+ sport->port.icount.tx++;
+ }
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&sport->port);
+
+ if (uart_circ_empty(xmit))
+ imx_uart_stop_tx(&sport->port);
+}
+
+static void imx_uart_dma_tx_callback(void *data)
+{
+ struct imx_port *sport = data;
+ struct scatterlist *sgl = &sport->tx_sgl[0];
+ struct circ_buf *xmit = &sport->port.state->xmit;
+ unsigned long flags;
+ u32 ucr1;
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+
+ dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
+
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr1 &= ~UCR1_TXDMAEN;
+ imx_uart_writel(sport, ucr1, UCR1);
+
+ /* update the stat */
+ xmit->tail = (xmit->tail + sport->tx_bytes) & (UART_XMIT_SIZE - 1);
+ sport->port.icount.tx += sport->tx_bytes;
+
+ dev_dbg(sport->port.dev, "we finish the TX DMA.\n");
+
+ sport->dma_is_txing = 0;
+
+ if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+ uart_write_wakeup(&sport->port);
+
+ if (!uart_circ_empty(xmit) && !uart_tx_stopped(&sport->port))
+ imx_uart_dma_tx(sport);
+ else if (sport->port.rs485.flags & SER_RS485_ENABLED) {
+ u32 ucr4 = imx_uart_readl(sport, UCR4);
+ ucr4 |= UCR4_TCEN;
+ imx_uart_writel(sport, ucr4, UCR4);
+ }
+
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_dma_tx(struct imx_port *sport)
+{
+ struct circ_buf *xmit = &sport->port.state->xmit;
+ struct scatterlist *sgl = sport->tx_sgl;
+ struct dma_async_tx_descriptor *desc;
+ struct dma_chan *chan = sport->dma_chan_tx;
+ struct device *dev = sport->port.dev;
+ u32 ucr1, ucr4;
+ int ret;
+
+ if (sport->dma_is_txing)
+ return;
+
+ ucr4 = imx_uart_readl(sport, UCR4);
+ ucr4 &= ~UCR4_TCEN;
+ imx_uart_writel(sport, ucr4, UCR4);
+
+ sport->tx_bytes = uart_circ_chars_pending(xmit);
+
+ if (xmit->tail < xmit->head) {
+ sport->dma_tx_nents = 1;
+ sg_init_one(sgl, xmit->buf + xmit->tail, sport->tx_bytes);
+ } else {
+ sport->dma_tx_nents = 2;
+ sg_init_table(sgl, 2);
+ sg_set_buf(sgl, xmit->buf + xmit->tail,
+ UART_XMIT_SIZE - xmit->tail);
+ sg_set_buf(sgl + 1, xmit->buf, xmit->head);
+ }
+
+ ret = dma_map_sg(dev, sgl, sport->dma_tx_nents, DMA_TO_DEVICE);
+ if (ret == 0) {
+ dev_err(dev, "DMA mapping error for TX.\n");
+ return;
+ }
+ desc = dmaengine_prep_slave_sg(chan, sgl, sport->dma_tx_nents,
+ DMA_MEM_TO_DEV, DMA_PREP_INTERRUPT);
+ if (!desc) {
+ dma_unmap_sg(dev, sgl, sport->dma_tx_nents,
+ DMA_TO_DEVICE);
+ dev_err(dev, "We cannot prepare for the TX slave dma!\n");
+ return;
+ }
+ desc->callback = imx_uart_dma_tx_callback;
+ desc->callback_param = sport;
+
+ dev_dbg(dev, "TX: prepare to send %lu bytes by DMA.\n",
+ uart_circ_chars_pending(xmit));
+
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr1 |= UCR1_TXDMAEN;
+ imx_uart_writel(sport, ucr1, UCR1);
+
+ /* fire it */
+ sport->dma_is_txing = 1;
+ dmaengine_submit(desc);
+ dma_async_issue_pending(chan);
+ return;
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_start_tx(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ u32 ucr1;
+
+ if (!sport->port.x_char && uart_circ_empty(&port->state->xmit))
+ return;
+
+ if (port->rs485.flags & SER_RS485_ENABLED) {
+ u32 ucr2;
+
+ ucr2 = imx_uart_readl(sport, UCR2);
+ if (port->rs485.flags & SER_RS485_RTS_ON_SEND)
+ imx_uart_rts_active(sport, &ucr2);
+ else
+ imx_uart_rts_inactive(sport, &ucr2);
+ imx_uart_writel(sport, ucr2, UCR2);
+
+ if (!(port->rs485.flags & SER_RS485_RX_DURING_TX))
+ imx_uart_stop_rx(port);
+
+ /*
+ * Enable transmitter and shifter empty irq only if DMA is off.
+ * In the DMA case this is done in the tx-callback.
+ */
+ if (!sport->dma_is_enabled) {
+ u32 ucr4 = imx_uart_readl(sport, UCR4);
+ ucr4 |= UCR4_TCEN;
+ imx_uart_writel(sport, ucr4, UCR4);
+ }
+ }
+
+ if (!sport->dma_is_enabled) {
+ ucr1 = imx_uart_readl(sport, UCR1);
+ imx_uart_writel(sport, ucr1 | UCR1_TXMPTYEN, UCR1);
+ }
+
+ if (sport->dma_is_enabled) {
+ if (sport->port.x_char) {
+ /* We have X-char to send, so enable TX IRQ and
+ * disable TX DMA to let TX interrupt to send X-char */
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr1 &= ~UCR1_TXDMAEN;
+ ucr1 |= UCR1_TXMPTYEN;
+ imx_uart_writel(sport, ucr1, UCR1);
+ return;
+ }
+
+ if (!uart_circ_empty(&port->state->xmit) &&
+ !uart_tx_stopped(port))
+ imx_uart_dma_tx(sport);
+ return;
+ }
+}
+
+static irqreturn_t imx_uart_rtsint(int irq, void *dev_id)
+{
+ struct imx_port *sport = dev_id;
+ u32 usr1;
+ unsigned long flags;
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+
+ imx_uart_writel(sport, USR1_RTSD, USR1);
+ usr1 = imx_uart_readl(sport, USR1) & USR1_RTSS;
+ uart_handle_cts_change(&sport->port, !!usr1);
+ wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
+
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t imx_uart_txint(int irq, void *dev_id)
+{
+ struct imx_port *sport = dev_id;
+ unsigned long flags;
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+ imx_uart_transmit_buffer(sport);
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t imx_uart_rxint(int irq, void *dev_id)
+{
+ struct imx_port *sport = dev_id;
+ unsigned int rx, flg, ignored = 0;
+ struct tty_port *port = &sport->port.state->port;
+ unsigned long flags;
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+
+ while (imx_uart_readl(sport, USR2) & USR2_RDR) {
+ u32 usr2;
+
+ flg = TTY_NORMAL;
+ sport->port.icount.rx++;
+
+ rx = imx_uart_readl(sport, URXD0);
+
+ usr2 = imx_uart_readl(sport, USR2);
+ if (usr2 & USR2_BRCD) {
+ imx_uart_writel(sport, USR2_BRCD, USR2);
+ if (uart_handle_break(&sport->port))
+ continue;
+ }
+
+ if (uart_handle_sysrq_char(&sport->port, (unsigned char)rx))
+ continue;
+
+ if (unlikely(rx & URXD_ERR)) {
+ if (rx & URXD_BRK)
+ sport->port.icount.brk++;
+ else if (rx & URXD_PRERR)
+ sport->port.icount.parity++;
+ else if (rx & URXD_FRMERR)
+ sport->port.icount.frame++;
+ if (rx & URXD_OVRRUN)
+ sport->port.icount.overrun++;
+
+ if (rx & sport->port.ignore_status_mask) {
+ if (++ignored > 100)
+ goto out;
+ continue;
+ }
+
+ rx &= (sport->port.read_status_mask | 0xFF);
+
+ if (rx & URXD_BRK)
+ flg = TTY_BREAK;
+ else if (rx & URXD_PRERR)
+ flg = TTY_PARITY;
+ else if (rx & URXD_FRMERR)
+ flg = TTY_FRAME;
+ if (rx & URXD_OVRRUN)
+ flg = TTY_OVERRUN;
+
+#ifdef SUPPORT_SYSRQ
+ sport->port.sysrq = 0;
+#endif
+ }
+
+ if (sport->port.ignore_status_mask & URXD_DUMMY_READ)
+ goto out;
+
+ if (tty_insert_flip_char(port, rx, flg) == 0)
+ sport->port.icount.buf_overrun++;
+ }
+
+out:
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+ tty_flip_buffer_push(port);
+ return IRQ_HANDLED;
+}
+
+static void imx_uart_clear_rx_errors(struct imx_port *sport);
+
+/*
+ * We have a modem side uart, so the meanings of RTS and CTS are inverted.
+ */
+static unsigned int imx_uart_get_hwmctrl(struct imx_port *sport)
+{
+ unsigned int tmp = TIOCM_DSR;
+ unsigned usr1 = imx_uart_readl(sport, USR1);
+ unsigned usr2 = imx_uart_readl(sport, USR2);
+
+ if (usr1 & USR1_RTSS)
+ tmp |= TIOCM_CTS;
+
+ /* in DCE mode DCDIN is always 0 */
+ if (!(usr2 & USR2_DCDIN))
+ tmp |= TIOCM_CAR;
+
+ if (sport->dte_mode)
+ if (!(imx_uart_readl(sport, USR2) & USR2_RIIN))
+ tmp |= TIOCM_RI;
+
+ return tmp;
+}
+
+/*
+ * Handle any change of modem status signal since we were last called.
+ */
+static void imx_uart_mctrl_check(struct imx_port *sport)
+{
+ unsigned int status, changed;
+
+ status = imx_uart_get_hwmctrl(sport);
+ changed = status ^ sport->old_status;
+
+ if (changed == 0)
+ return;
+
+ sport->old_status = status;
+
+ if (changed & TIOCM_RI && status & TIOCM_RI)
+ sport->port.icount.rng++;
+ if (changed & TIOCM_DSR)
+ sport->port.icount.dsr++;
+ if (changed & TIOCM_CAR)
+ uart_handle_dcd_change(&sport->port, status & TIOCM_CAR);
+ if (changed & TIOCM_CTS)
+ uart_handle_cts_change(&sport->port, status & TIOCM_CTS);
+
+ wake_up_interruptible(&sport->port.state->port.delta_msr_wait);
+}
+
+static irqreturn_t imx_uart_int(int irq, void *dev_id)
+{
+ struct imx_port *sport = dev_id;
+ unsigned int usr1, usr2, ucr1, ucr2, ucr3, ucr4;
+ irqreturn_t ret = IRQ_NONE;
+
+ usr1 = imx_uart_readl(sport, USR1);
+ usr2 = imx_uart_readl(sport, USR2);
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr2 = imx_uart_readl(sport, UCR2);
+ ucr3 = imx_uart_readl(sport, UCR3);
+ ucr4 = imx_uart_readl(sport, UCR4);
+
+ /*
+ * Even if a condition is true that can trigger an irq only handle it if
+ * the respective irq source is enabled. This prevents some undesired
+ * actions, for example if a character that sits in the RX FIFO and that
+ * should be fetched via DMA is tried to be fetched using PIO. Or the
+ * receiver is currently off and so reading from URXD0 results in an
+ * exception. So just mask the (raw) status bits for disabled irqs.
+ */
+ if ((ucr1 & UCR1_RRDYEN) == 0)
+ usr1 &= ~USR1_RRDY;
+ if ((ucr2 & UCR2_ATEN) == 0)
+ usr1 &= ~USR1_AGTIM;
+ if ((ucr1 & UCR1_TXMPTYEN) == 0)
+ usr1 &= ~USR1_TRDY;
+ if ((ucr4 & UCR4_TCEN) == 0)
+ usr2 &= ~USR2_TXDC;
+ if ((ucr3 & UCR3_DTRDEN) == 0)
+ usr1 &= ~USR1_DTRD;
+ if ((ucr1 & UCR1_RTSDEN) == 0)
+ usr1 &= ~USR1_RTSD;
+ if ((ucr3 & UCR3_AWAKEN) == 0)
+ usr1 &= ~USR1_AWAKE;
+ if ((ucr4 & UCR4_OREN) == 0)
+ usr2 &= ~USR2_ORE;
+
+ if (usr1 & (USR1_RRDY | USR1_AGTIM)) {
+ imx_uart_rxint(irq, dev_id);
+ ret = IRQ_HANDLED;
+ }
+
+ if ((usr1 & USR1_TRDY) || (usr2 & USR2_TXDC)) {
+ imx_uart_txint(irq, dev_id);
+ ret = IRQ_HANDLED;
+ }
+
+ if (usr1 & USR1_DTRD) {
+ unsigned long flags;
+
+ imx_uart_writel(sport, USR1_DTRD, USR1);
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+ imx_uart_mctrl_check(sport);
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+
+ ret = IRQ_HANDLED;
+ }
+
+ if (usr1 & USR1_RTSD) {
+ imx_uart_rtsint(irq, dev_id);
+ ret = IRQ_HANDLED;
+ }
+
+ if (usr1 & USR1_AWAKE) {
+ imx_uart_writel(sport, USR1_AWAKE, USR1);
+ ret = IRQ_HANDLED;
+ }
+
+ if (usr2 & USR2_ORE) {
+ sport->port.icount.overrun++;
+ imx_uart_writel(sport, USR2_ORE, USR2);
+ ret = IRQ_HANDLED;
+ }
+
+ return ret;
+}
+
+/*
+ * Return TIOCSER_TEMT when transmitter is not busy.
+ */
+static unsigned int imx_uart_tx_empty(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ unsigned int ret;
+
+ ret = (imx_uart_readl(sport, USR2) & USR2_TXDC) ? TIOCSER_TEMT : 0;
+
+ /* If the TX DMA is working, return 0. */
+ if (sport->dma_is_txing)
+ ret = 0;
+
+ return ret;
+}
+
+/* called with port.lock taken and irqs off */
+static unsigned int imx_uart_get_mctrl(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ unsigned int ret = imx_uart_get_hwmctrl(sport);
+
+ mctrl_gpio_get(sport->gpios, &ret);
+
+ return ret;
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ u32 ucr3, uts;
+
+ if (!(port->rs485.flags & SER_RS485_ENABLED)) {
+ u32 ucr2;
+
+ ucr2 = imx_uart_readl(sport, UCR2);
+ ucr2 &= ~(UCR2_CTS | UCR2_CTSC);
+ if (mctrl & TIOCM_RTS)
+ ucr2 |= UCR2_CTS | UCR2_CTSC;
+ imx_uart_writel(sport, ucr2, UCR2);
+ }
+
+ ucr3 = imx_uart_readl(sport, UCR3) & ~UCR3_DSR;
+ if (!(mctrl & TIOCM_DTR))
+ ucr3 |= UCR3_DSR;
+ imx_uart_writel(sport, ucr3, UCR3);
+
+ uts = imx_uart_readl(sport, imx_uart_uts_reg(sport)) & ~UTS_LOOP;
+ if (mctrl & TIOCM_LOOP)
+ uts |= UTS_LOOP;
+ imx_uart_writel(sport, uts, imx_uart_uts_reg(sport));
+
+ mctrl_gpio_set(sport->gpios, mctrl);
+}
+
+/*
+ * Interrupts always disabled.
+ */
+static void imx_uart_break_ctl(struct uart_port *port, int break_state)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ unsigned long flags;
+ u32 ucr1;
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+
+ ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_SNDBRK;
+
+ if (break_state != 0)
+ ucr1 |= UCR1_SNDBRK;
+
+ imx_uart_writel(sport, ucr1, UCR1);
+
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+/*
+ * This is our per-port timeout handler, for checking the
+ * modem status signals.
+ */
+static void imx_uart_timeout(struct timer_list *t)
+{
+ struct imx_port *sport = from_timer(sport, t, timer);
+ unsigned long flags;
+
+ if (sport->port.state) {
+ spin_lock_irqsave(&sport->port.lock, flags);
+ imx_uart_mctrl_check(sport);
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+
+ mod_timer(&sport->timer, jiffies + MCTRL_TIMEOUT);
+ }
+}
+
+#define RX_BUF_SIZE (PAGE_SIZE)
+
+/*
+ * There are two kinds of RX DMA interrupts(such as in the MX6Q):
+ * [1] the RX DMA buffer is full.
+ * [2] the aging timer expires
+ *
+ * Condition [2] is triggered when a character has been sitting in the FIFO
+ * for at least 8 byte durations.
+ */
+static void imx_uart_dma_rx_callback(void *data)
+{
+ struct imx_port *sport = data;
+ struct dma_chan *chan = sport->dma_chan_rx;
+ struct scatterlist *sgl = &sport->rx_sgl;
+ struct tty_port *port = &sport->port.state->port;
+ struct dma_tx_state state;
+ struct circ_buf *rx_ring = &sport->rx_ring;
+ enum dma_status status;
+ unsigned int w_bytes = 0;
+ unsigned int r_bytes;
+ unsigned int bd_size;
+
+ status = dmaengine_tx_status(chan, sport->rx_cookie, &state);
+
+ if (status == DMA_ERROR) {
+ imx_uart_clear_rx_errors(sport);
+ return;
+ }
+
+ if (!(sport->port.ignore_status_mask & URXD_DUMMY_READ)) {
+
+ /*
+ * The state-residue variable represents the empty space
+ * relative to the entire buffer. Taking this in consideration
+ * the head is always calculated base on the buffer total
+ * length - DMA transaction residue. The UART script from the
+ * SDMA firmware will jump to the next buffer descriptor,
+ * once a DMA transaction if finalized (IMX53 RM - A.4.1.2.4).
+ * Taking this in consideration the tail is always at the
+ * beginning of the buffer descriptor that contains the head.
+ */
+
+ /* Calculate the head */
+ rx_ring->head = sg_dma_len(sgl) - state.residue;
+
+ /* Calculate the tail. */
+ bd_size = sg_dma_len(sgl) / sport->rx_periods;
+ rx_ring->tail = ((rx_ring->head-1) / bd_size) * bd_size;
+
+ if (rx_ring->head <= sg_dma_len(sgl) &&
+ rx_ring->head > rx_ring->tail) {
+
+ /* Move data from tail to head */
+ r_bytes = rx_ring->head - rx_ring->tail;
+
+ /* CPU claims ownership of RX DMA buffer */
+ dma_sync_sg_for_cpu(sport->port.dev, sgl, 1,
+ DMA_FROM_DEVICE);
+
+ w_bytes = tty_insert_flip_string(port,
+ sport->rx_buf + rx_ring->tail, r_bytes);
+
+ /* UART retrieves ownership of RX DMA buffer */
+ dma_sync_sg_for_device(sport->port.dev, sgl, 1,
+ DMA_FROM_DEVICE);
+
+ if (w_bytes != r_bytes)
+ sport->port.icount.buf_overrun++;
+
+ sport->port.icount.rx += w_bytes;
+ } else {
+ WARN_ON(rx_ring->head > sg_dma_len(sgl));
+ WARN_ON(rx_ring->head <= rx_ring->tail);
+ }
+ }
+
+ if (w_bytes) {
+ tty_flip_buffer_push(port);
+ dev_dbg(sport->port.dev, "We get %d bytes.\n", w_bytes);
+ }
+}
+
+/* RX DMA buffer periods */
+#define RX_DMA_PERIODS 4
+
+static int imx_uart_start_rx_dma(struct imx_port *sport)
+{
+ struct scatterlist *sgl = &sport->rx_sgl;
+ struct dma_chan *chan = sport->dma_chan_rx;
+ struct device *dev = sport->port.dev;
+ struct dma_async_tx_descriptor *desc;
+ int ret;
+
+ sport->rx_ring.head = 0;
+ sport->rx_ring.tail = 0;
+ sport->rx_periods = RX_DMA_PERIODS;
+
+ sg_init_one(sgl, sport->rx_buf, RX_BUF_SIZE);
+ ret = dma_map_sg(dev, sgl, 1, DMA_FROM_DEVICE);
+ if (ret == 0) {
+ dev_err(dev, "DMA mapping error for RX.\n");
+ return -EINVAL;
+ }
+
+ desc = dmaengine_prep_dma_cyclic(chan, sg_dma_address(sgl),
+ sg_dma_len(sgl), sg_dma_len(sgl) / sport->rx_periods,
+ DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
+
+ if (!desc) {
+ dma_unmap_sg(dev, sgl, 1, DMA_FROM_DEVICE);
+ dev_err(dev, "We cannot prepare for the RX slave dma!\n");
+ return -EINVAL;
+ }
+ desc->callback = imx_uart_dma_rx_callback;
+ desc->callback_param = sport;
+
+ dev_dbg(dev, "RX: prepare for the DMA.\n");
+ sport->dma_is_rxing = 1;
+ sport->rx_cookie = dmaengine_submit(desc);
+ dma_async_issue_pending(chan);
+ return 0;
+}
+
+static void imx_uart_clear_rx_errors(struct imx_port *sport)
+{
+ struct tty_port *port = &sport->port.state->port;
+ u32 usr1, usr2;
+
+ usr1 = imx_uart_readl(sport, USR1);
+ usr2 = imx_uart_readl(sport, USR2);
+
+ if (usr2 & USR2_BRCD) {
+ sport->port.icount.brk++;
+ imx_uart_writel(sport, USR2_BRCD, USR2);
+ uart_handle_break(&sport->port);
+ if (tty_insert_flip_char(port, 0, TTY_BREAK) == 0)
+ sport->port.icount.buf_overrun++;
+ tty_flip_buffer_push(port);
+ } else {
+ dev_err(sport->port.dev, "DMA transaction error.\n");
+ if (usr1 & USR1_FRAMERR) {
+ sport->port.icount.frame++;
+ imx_uart_writel(sport, USR1_FRAMERR, USR1);
+ } else if (usr1 & USR1_PARITYERR) {
+ sport->port.icount.parity++;
+ imx_uart_writel(sport, USR1_PARITYERR, USR1);
+ }
+ }
+
+ if (usr2 & USR2_ORE) {
+ sport->port.icount.overrun++;
+ imx_uart_writel(sport, USR2_ORE, USR2);
+ }
+
+}
+
+#define TXTL_DEFAULT 2 /* reset default */
+#define RXTL_DEFAULT 1 /* reset default */
+#define TXTL_DMA 8 /* DMA burst setting */
+#define RXTL_DMA 9 /* DMA burst setting */
+
+static void imx_uart_setup_ufcr(struct imx_port *sport,
+ unsigned char txwl, unsigned char rxwl)
+{
+ unsigned int val;
+
+ /* set receiver / transmitter trigger level */
+ val = imx_uart_readl(sport, UFCR) & (UFCR_RFDIV | UFCR_DCEDTE);
+ val |= txwl << UFCR_TXTL_SHF | rxwl;
+ imx_uart_writel(sport, val, UFCR);
+}
+
+static void imx_uart_dma_exit(struct imx_port *sport)
+{
+ if (sport->dma_chan_rx) {
+ dmaengine_terminate_sync(sport->dma_chan_rx);
+ dma_release_channel(sport->dma_chan_rx);
+ sport->dma_chan_rx = NULL;
+ sport->rx_cookie = -EINVAL;
+ kfree(sport->rx_buf);
+ sport->rx_buf = NULL;
+ }
+
+ if (sport->dma_chan_tx) {
+ dmaengine_terminate_sync(sport->dma_chan_tx);
+ dma_release_channel(sport->dma_chan_tx);
+ sport->dma_chan_tx = NULL;
+ }
+}
+
+static int imx_uart_dma_init(struct imx_port *sport)
+{
+ struct dma_slave_config slave_config = {};
+ struct device *dev = sport->port.dev;
+ int ret;
+
+ /* Prepare for RX : */
+ sport->dma_chan_rx = dma_request_slave_channel(dev, "rx");
+ if (!sport->dma_chan_rx) {
+ dev_dbg(dev, "cannot get the DMA channel.\n");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ slave_config.direction = DMA_DEV_TO_MEM;
+ slave_config.src_addr = sport->port.mapbase + URXD0;
+ slave_config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ /* one byte less than the watermark level to enable the aging timer */
+ slave_config.src_maxburst = RXTL_DMA - 1;
+ ret = dmaengine_slave_config(sport->dma_chan_rx, &slave_config);
+ if (ret) {
+ dev_err(dev, "error in RX dma configuration.\n");
+ goto err;
+ }
+
+ sport->rx_buf = kzalloc(RX_BUF_SIZE, GFP_KERNEL);
+ if (!sport->rx_buf) {
+ ret = -ENOMEM;
+ goto err;
+ }
+ sport->rx_ring.buf = sport->rx_buf;
+
+ /* Prepare for TX : */
+ sport->dma_chan_tx = dma_request_slave_channel(dev, "tx");
+ if (!sport->dma_chan_tx) {
+ dev_err(dev, "cannot get the TX DMA channel!\n");
+ ret = -EINVAL;
+ goto err;
+ }
+
+ slave_config.direction = DMA_MEM_TO_DEV;
+ slave_config.dst_addr = sport->port.mapbase + URTX0;
+ slave_config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ slave_config.dst_maxburst = TXTL_DMA;
+ ret = dmaengine_slave_config(sport->dma_chan_tx, &slave_config);
+ if (ret) {
+ dev_err(dev, "error in TX dma configuration.");
+ goto err;
+ }
+
+ return 0;
+err:
+ imx_uart_dma_exit(sport);
+ return ret;
+}
+
+static void imx_uart_enable_dma(struct imx_port *sport)
+{
+ u32 ucr1;
+
+ imx_uart_setup_ufcr(sport, TXTL_DMA, RXTL_DMA);
+
+ /* set UCR1 */
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr1 |= UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN;
+ imx_uart_writel(sport, ucr1, UCR1);
+
+ sport->dma_is_enabled = 1;
+}
+
+static void imx_uart_disable_dma(struct imx_port *sport)
+{
+ u32 ucr1;
+
+ /* clear UCR1 */
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr1 &= ~(UCR1_RXDMAEN | UCR1_TXDMAEN | UCR1_ATDMAEN);
+ imx_uart_writel(sport, ucr1, UCR1);
+
+ imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
+
+ sport->dma_is_enabled = 0;
+}
+
+/* half the RX buffer size */
+#define CTSTL 16
+
+static int imx_uart_startup(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ int retval, i;
+ unsigned long flags;
+ int dma_is_inited = 0;
+ u32 ucr1, ucr2, ucr4;
+
+ retval = clk_prepare_enable(sport->clk_per);
+ if (retval)
+ return retval;
+ retval = clk_prepare_enable(sport->clk_ipg);
+ if (retval) {
+ clk_disable_unprepare(sport->clk_per);
+ return retval;
+ }
+
+ imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
+
+ /* disable the DREN bit (Data Ready interrupt enable) before
+ * requesting IRQs
+ */
+ ucr4 = imx_uart_readl(sport, UCR4);
+
+ /* set the trigger level for CTS */
+ ucr4 &= ~(UCR4_CTSTL_MASK << UCR4_CTSTL_SHF);
+ ucr4 |= CTSTL << UCR4_CTSTL_SHF;
+
+ imx_uart_writel(sport, ucr4 & ~UCR4_DREN, UCR4);
+
+ /* Can we enable the DMA support? */
+ if (!uart_console(port) && imx_uart_dma_init(sport) == 0)
+ dma_is_inited = 1;
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+ /* Reset fifo's and state machines */
+ i = 100;
+
+ ucr2 = imx_uart_readl(sport, UCR2);
+ ucr2 &= ~UCR2_SRST;
+ imx_uart_writel(sport, ucr2, UCR2);
+
+ while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
+ udelay(1);
+
+ /*
+ * Finally, clear and enable interrupts
+ */
+ imx_uart_writel(sport, USR1_RTSD | USR1_DTRD, USR1);
+ imx_uart_writel(sport, USR2_ORE, USR2);
+
+ ucr1 = imx_uart_readl(sport, UCR1) & ~UCR1_RRDYEN;
+ ucr1 |= UCR1_UARTEN;
+ if (sport->have_rtscts)
+ ucr1 |= UCR1_RTSDEN;
+
+ imx_uart_writel(sport, ucr1, UCR1);
+
+ ucr4 = imx_uart_readl(sport, UCR4) & ~UCR4_OREN;
+ if (!sport->dma_is_enabled)
+ ucr4 |= UCR4_OREN;
+ imx_uart_writel(sport, ucr4, UCR4);
+
+ ucr2 = imx_uart_readl(sport, UCR2) & ~UCR2_ATEN;
+ ucr2 |= (UCR2_RXEN | UCR2_TXEN);
+ if (!sport->have_rtscts)
+ ucr2 |= UCR2_IRTS;
+ /*
+ * make sure the edge sensitive RTS-irq is disabled,
+ * we're using RTSD instead.
+ */
+ if (!imx_uart_is_imx1(sport))
+ ucr2 &= ~UCR2_RTSEN;
+ imx_uart_writel(sport, ucr2, UCR2);
+
+ if (!imx_uart_is_imx1(sport)) {
+ u32 ucr3;
+
+ ucr3 = imx_uart_readl(sport, UCR3);
+
+ ucr3 |= UCR3_DTRDEN | UCR3_RI | UCR3_DCD;
+
+ if (sport->dte_mode)
+ /* disable broken interrupts */
+ ucr3 &= ~(UCR3_RI | UCR3_DCD);
+
+ imx_uart_writel(sport, ucr3, UCR3);
+ }
+
+ /*
+ * Enable modem status interrupts
+ */
+ imx_uart_enable_ms(&sport->port);
+
+ if (dma_is_inited) {
+ imx_uart_enable_dma(sport);
+ imx_uart_start_rx_dma(sport);
+ } else {
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr1 |= UCR1_RRDYEN;
+ imx_uart_writel(sport, ucr1, UCR1);
+
+ ucr2 = imx_uart_readl(sport, UCR2);
+ ucr2 |= UCR2_ATEN;
+ imx_uart_writel(sport, ucr2, UCR2);
+ }
+
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+
+ return 0;
+}
+
+static void imx_uart_shutdown(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ unsigned long flags;
+ u32 ucr1, ucr2, ucr4;
+
+ if (sport->dma_is_enabled) {
+ dmaengine_terminate_sync(sport->dma_chan_tx);
+ if (sport->dma_is_txing) {
+ dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
+ sport->dma_tx_nents, DMA_TO_DEVICE);
+ sport->dma_is_txing = 0;
+ }
+ dmaengine_terminate_sync(sport->dma_chan_rx);
+ if (sport->dma_is_rxing) {
+ dma_unmap_sg(sport->port.dev, &sport->rx_sgl,
+ 1, DMA_FROM_DEVICE);
+ sport->dma_is_rxing = 0;
+ }
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+ imx_uart_stop_tx(port);
+ imx_uart_stop_rx(port);
+ imx_uart_disable_dma(sport);
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+ imx_uart_dma_exit(sport);
+ }
+
+ mctrl_gpio_disable_ms(sport->gpios);
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+ ucr2 = imx_uart_readl(sport, UCR2);
+ ucr2 &= ~(UCR2_TXEN | UCR2_ATEN);
+ imx_uart_writel(sport, ucr2, UCR2);
+
+ ucr4 = imx_uart_readl(sport, UCR4);
+ ucr4 &= ~UCR4_OREN;
+ imx_uart_writel(sport, ucr4, UCR4);
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+
+ /*
+ * Stop our timer.
+ */
+ del_timer_sync(&sport->timer);
+
+ /*
+ * Disable all interrupts, port and break condition.
+ */
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN | UCR1_UARTEN | UCR1_RXDMAEN | UCR1_ATDMAEN);
+
+ imx_uart_writel(sport, ucr1, UCR1);
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+
+ clk_disable_unprepare(sport->clk_per);
+ clk_disable_unprepare(sport->clk_ipg);
+}
+
+/* called with port.lock taken and irqs off */
+static void imx_uart_flush_buffer(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ struct scatterlist *sgl = &sport->tx_sgl[0];
+ u32 ucr2;
+ int i = 100, ubir, ubmr, uts;
+
+ if (!sport->dma_chan_tx)
+ return;
+
+ sport->tx_bytes = 0;
+ dmaengine_terminate_all(sport->dma_chan_tx);
+ if (sport->dma_is_txing) {
+ u32 ucr1;
+
+ dma_unmap_sg(sport->port.dev, sgl, sport->dma_tx_nents,
+ DMA_TO_DEVICE);
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr1 &= ~UCR1_TXDMAEN;
+ imx_uart_writel(sport, ucr1, UCR1);
+ sport->dma_is_txing = 0;
+ }
+
+ /*
+ * According to the Reference Manual description of the UART SRST bit:
+ *
+ * "Reset the transmit and receive state machines,
+ * all FIFOs and register USR1, USR2, UBIR, UBMR, UBRC, URXD, UTXD
+ * and UTS[6-3]".
+ *
+ * We don't need to restore the old values from USR1, USR2, URXD and
+ * UTXD. UBRC is read only, so only save/restore the other three
+ * registers.
+ */
+ ubir = imx_uart_readl(sport, UBIR);
+ ubmr = imx_uart_readl(sport, UBMR);
+ uts = imx_uart_readl(sport, IMX21_UTS);
+
+ ucr2 = imx_uart_readl(sport, UCR2);
+ ucr2 &= ~UCR2_SRST;
+ imx_uart_writel(sport, ucr2, UCR2);
+
+ while (!(imx_uart_readl(sport, UCR2) & UCR2_SRST) && (--i > 0))
+ udelay(1);
+
+ /* Restore the registers */
+ imx_uart_writel(sport, ubir, UBIR);
+ imx_uart_writel(sport, ubmr, UBMR);
+ imx_uart_writel(sport, uts, IMX21_UTS);
+}
+
+static void
+imx_uart_set_termios(struct uart_port *port, struct ktermios *termios,
+ struct ktermios *old)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ unsigned long flags;
+ u32 ucr2, old_ucr1, old_ucr2, ufcr;
+ unsigned int baud, quot;
+ unsigned int old_csize = old ? old->c_cflag & CSIZE : CS8;
+ unsigned long div;
+ unsigned long num, denom;
+ uint64_t tdiv64;
+
+ /*
+ * We only support CS7 and CS8.
+ */
+ while ((termios->c_cflag & CSIZE) != CS7 &&
+ (termios->c_cflag & CSIZE) != CS8) {
+ termios->c_cflag &= ~CSIZE;
+ termios->c_cflag |= old_csize;
+ old_csize = CS8;
+ }
+
+ if ((termios->c_cflag & CSIZE) == CS8)
+ ucr2 = UCR2_WS | UCR2_SRST | UCR2_IRTS;
+ else
+ ucr2 = UCR2_SRST | UCR2_IRTS;
+
+ if (termios->c_cflag & CRTSCTS) {
+ if (sport->have_rtscts) {
+ ucr2 &= ~UCR2_IRTS;
+
+ if (port->rs485.flags & SER_RS485_ENABLED) {
+ /*
+ * RTS is mandatory for rs485 operation, so keep
+ * it under manual control and keep transmitter
+ * disabled.
+ */
+ if (port->rs485.flags &
+ SER_RS485_RTS_AFTER_SEND)
+ imx_uart_rts_active(sport, &ucr2);
+ else
+ imx_uart_rts_inactive(sport, &ucr2);
+ } else {
+ imx_uart_rts_auto(sport, &ucr2);
+ }
+ } else {
+ termios->c_cflag &= ~CRTSCTS;
+ }
+ } else if (port->rs485.flags & SER_RS485_ENABLED) {
+ /* disable transmitter */
+ if (port->rs485.flags & SER_RS485_RTS_AFTER_SEND)
+ imx_uart_rts_active(sport, &ucr2);
+ else
+ imx_uart_rts_inactive(sport, &ucr2);
+ }
+
+
+ if (termios->c_cflag & CSTOPB)
+ ucr2 |= UCR2_STPB;
+ if (termios->c_cflag & PARENB) {
+ ucr2 |= UCR2_PREN;
+ if (termios->c_cflag & PARODD)
+ ucr2 |= UCR2_PROE;
+ }
+
+ del_timer_sync(&sport->timer);
+
+ /*
+ * Ask the core to calculate the divisor for us.
+ */
+ baud = uart_get_baud_rate(port, termios, old, 50, port->uartclk / 16);
+ quot = uart_get_divisor(port, baud);
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+
+ sport->port.read_status_mask = 0;
+ if (termios->c_iflag & INPCK)
+ sport->port.read_status_mask |= (URXD_FRMERR | URXD_PRERR);
+ if (termios->c_iflag & (BRKINT | PARMRK))
+ sport->port.read_status_mask |= URXD_BRK;
+
+ /*
+ * Characters to ignore
+ */
+ sport->port.ignore_status_mask = 0;
+ if (termios->c_iflag & IGNPAR)
+ sport->port.ignore_status_mask |= URXD_PRERR | URXD_FRMERR;
+ if (termios->c_iflag & IGNBRK) {
+ sport->port.ignore_status_mask |= URXD_BRK;
+ /*
+ * If we're ignoring parity and break indicators,
+ * ignore overruns too (for real raw support).
+ */
+ if (termios->c_iflag & IGNPAR)
+ sport->port.ignore_status_mask |= URXD_OVRRUN;
+ }
+
+ if ((termios->c_cflag & CREAD) == 0)
+ sport->port.ignore_status_mask |= URXD_DUMMY_READ;
+
+ /*
+ * Update the per-port timeout.
+ */
+ uart_update_timeout(port, termios->c_cflag, baud);
+
+ /*
+ * disable interrupts and drain transmitter
+ */
+ old_ucr1 = imx_uart_readl(sport, UCR1);
+ imx_uart_writel(sport,
+ old_ucr1 & ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN),
+ UCR1);
+ old_ucr2 = imx_uart_readl(sport, UCR2);
+ imx_uart_writel(sport, old_ucr2 & ~UCR2_ATEN, UCR2);
+
+ while (!(imx_uart_readl(sport, USR2) & USR2_TXDC))
+ barrier();
+
+ /* then, disable everything */
+ imx_uart_writel(sport, old_ucr2 & ~(UCR2_TXEN | UCR2_RXEN | UCR2_ATEN), UCR2);
+ old_ucr2 &= (UCR2_TXEN | UCR2_RXEN | UCR2_ATEN);
+
+ /* custom-baudrate handling */
+ div = sport->port.uartclk / (baud * 16);
+ if (baud == 38400 && quot != div)
+ baud = sport->port.uartclk / (quot * 16);
+
+ div = sport->port.uartclk / (baud * 16);
+ if (div > 7)
+ div = 7;
+ if (!div)
+ div = 1;
+
+ rational_best_approximation(16 * div * baud, sport->port.uartclk,
+ 1 << 16, 1 << 16, &num, &denom);
+
+ tdiv64 = sport->port.uartclk;
+ tdiv64 *= num;
+ do_div(tdiv64, denom * 16 * div);
+ tty_termios_encode_baud_rate(termios,
+ (speed_t)tdiv64, (speed_t)tdiv64);
+
+ num -= 1;
+ denom -= 1;
+
+ ufcr = imx_uart_readl(sport, UFCR);
+ ufcr = (ufcr & (~UFCR_RFDIV)) | UFCR_RFDIV_REG(div);
+ imx_uart_writel(sport, ufcr, UFCR);
+
+ imx_uart_writel(sport, num, UBIR);
+ imx_uart_writel(sport, denom, UBMR);
+
+ if (!imx_uart_is_imx1(sport))
+ imx_uart_writel(sport, sport->port.uartclk / div / 1000,
+ IMX21_ONEMS);
+
+ imx_uart_writel(sport, old_ucr1, UCR1);
+
+ /* set the parity, stop bits and data size */
+ imx_uart_writel(sport, ucr2 | old_ucr2, UCR2);
+
+ if (UART_ENABLE_MS(&sport->port, termios->c_cflag))
+ imx_uart_enable_ms(&sport->port);
+
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+}
+
+static const char *imx_uart_type(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+
+ return sport->port.type == PORT_IMX ? "IMX" : NULL;
+}
+
+/*
+ * Configure/autoconfigure the port.
+ */
+static void imx_uart_config_port(struct uart_port *port, int flags)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+
+ if (flags & UART_CONFIG_TYPE)
+ sport->port.type = PORT_IMX;
+}
+
+/*
+ * Verify the new serial_struct (for TIOCSSERIAL).
+ * The only change we allow are to the flags and type, and
+ * even then only between PORT_IMX and PORT_UNKNOWN
+ */
+static int
+imx_uart_verify_port(struct uart_port *port, struct serial_struct *ser)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ int ret = 0;
+
+ if (ser->type != PORT_UNKNOWN && ser->type != PORT_IMX)
+ ret = -EINVAL;
+ if (sport->port.irq != ser->irq)
+ ret = -EINVAL;
+ if (ser->io_type != UPIO_MEM)
+ ret = -EINVAL;
+ if (sport->port.uartclk / 16 != ser->baud_base)
+ ret = -EINVAL;
+ if (sport->port.mapbase != (unsigned long)ser->iomem_base)
+ ret = -EINVAL;
+ if (sport->port.iobase != ser->port)
+ ret = -EINVAL;
+ if (ser->hub6 != 0)
+ ret = -EINVAL;
+ return ret;
+}
+
+#if defined(CONFIG_CONSOLE_POLL)
+
+static int imx_uart_poll_init(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ unsigned long flags;
+ u32 ucr1, ucr2;
+ int retval;
+
+ retval = clk_prepare_enable(sport->clk_ipg);
+ if (retval)
+ return retval;
+ retval = clk_prepare_enable(sport->clk_per);
+ if (retval)
+ clk_disable_unprepare(sport->clk_ipg);
+
+ imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
+
+ spin_lock_irqsave(&sport->port.lock, flags);
+
+ /*
+ * Be careful about the order of enabling bits here. First enable the
+ * receiver (UARTEN + RXEN) and only then the corresponding irqs.
+ * This prevents that a character that already sits in the RX fifo is
+ * triggering an irq but the try to fetch it from there results in an
+ * exception because UARTEN or RXEN is still off.
+ */
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr2 = imx_uart_readl(sport, UCR2);
+
+ if (imx_uart_is_imx1(sport))
+ ucr1 |= IMX1_UCR1_UARTCLKEN;
+
+ ucr1 |= UCR1_UARTEN;
+ ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RTSDEN | UCR1_RRDYEN);
+
+ ucr2 |= UCR2_RXEN;
+ ucr2 &= ~UCR2_ATEN;
+
+ imx_uart_writel(sport, ucr1, UCR1);
+ imx_uart_writel(sport, ucr2, UCR2);
+
+ /* now enable irqs */
+ imx_uart_writel(sport, ucr1 | UCR1_RRDYEN, UCR1);
+ imx_uart_writel(sport, ucr2 | UCR2_ATEN, UCR2);
+
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+
+ return 0;
+}
+
+static int imx_uart_poll_get_char(struct uart_port *port)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ if (!(imx_uart_readl(sport, USR2) & USR2_RDR))
+ return NO_POLL_CHAR;
+
+ return imx_uart_readl(sport, URXD0) & URXD_RX_DATA;
+}
+
+static void imx_uart_poll_put_char(struct uart_port *port, unsigned char c)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ unsigned int status;
+
+ /* drain */
+ do {
+ status = imx_uart_readl(sport, USR1);
+ } while (~status & USR1_TRDY);
+
+ /* write */
+ imx_uart_writel(sport, c, URTX0);
+
+ /* flush */
+ do {
+ status = imx_uart_readl(sport, USR2);
+ } while (~status & USR2_TXDC);
+}
+#endif
+
+/* called with port.lock taken and irqs off or from .probe without locking */
+static int imx_uart_rs485_config(struct uart_port *port,
+ struct serial_rs485 *rs485conf)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+ u32 ucr2;
+
+ /* unimplemented */
+ rs485conf->delay_rts_before_send = 0;
+ rs485conf->delay_rts_after_send = 0;
+
+ /* RTS is required to control the transmitter */
+ if (!sport->have_rtscts && !sport->have_rtsgpio)
+ rs485conf->flags &= ~SER_RS485_ENABLED;
+
+ if (rs485conf->flags & SER_RS485_ENABLED) {
+ /* Enable receiver if low-active RTS signal is requested */
+ if (sport->have_rtscts && !sport->have_rtsgpio &&
+ !(rs485conf->flags & SER_RS485_RTS_ON_SEND))
+ rs485conf->flags |= SER_RS485_RX_DURING_TX;
+
+ /* disable transmitter */
+ ucr2 = imx_uart_readl(sport, UCR2);
+ if (rs485conf->flags & SER_RS485_RTS_AFTER_SEND)
+ imx_uart_rts_active(sport, &ucr2);
+ else
+ imx_uart_rts_inactive(sport, &ucr2);
+ imx_uart_writel(sport, ucr2, UCR2);
+ }
+
+ /* Make sure Rx is enabled in case Tx is active with Rx disabled */
+ if (!(rs485conf->flags & SER_RS485_ENABLED) ||
+ rs485conf->flags & SER_RS485_RX_DURING_TX)
+ imx_uart_start_rx(port);
+
+ port->rs485 = *rs485conf;
+
+ return 0;
+}
+
+static const struct uart_ops imx_uart_pops = {
+ .tx_empty = imx_uart_tx_empty,
+ .set_mctrl = imx_uart_set_mctrl,
+ .get_mctrl = imx_uart_get_mctrl,
+ .stop_tx = imx_uart_stop_tx,
+ .start_tx = imx_uart_start_tx,
+ .stop_rx = imx_uart_stop_rx,
+ .enable_ms = imx_uart_enable_ms,
+ .break_ctl = imx_uart_break_ctl,
+ .startup = imx_uart_startup,
+ .shutdown = imx_uart_shutdown,
+ .flush_buffer = imx_uart_flush_buffer,
+ .set_termios = imx_uart_set_termios,
+ .type = imx_uart_type,
+ .config_port = imx_uart_config_port,
+ .verify_port = imx_uart_verify_port,
+#if defined(CONFIG_CONSOLE_POLL)
+ .poll_init = imx_uart_poll_init,
+ .poll_get_char = imx_uart_poll_get_char,
+ .poll_put_char = imx_uart_poll_put_char,
+#endif
+};
+
+static struct imx_port *imx_uart_ports[UART_NR];
+
+#ifdef CONFIG_SERIAL_IMX_CONSOLE
+static void imx_uart_console_putchar(struct uart_port *port, int ch)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+
+ while (imx_uart_readl(sport, imx_uart_uts_reg(sport)) & UTS_TXFULL)
+ barrier();
+
+ imx_uart_writel(sport, ch, URTX0);
+}
+
+/*
+ * Interrupts are disabled on entering
+ */
+static void
+imx_uart_console_write(struct console *co, const char *s, unsigned int count)
+{
+ struct imx_port *sport = imx_uart_ports[co->index];
+ struct imx_port_ucrs old_ucr;
+ unsigned int ucr1;
+ unsigned long flags = 0;
+ int locked = 1;
+ int retval;
+
+ retval = clk_enable(sport->clk_per);
+ if (retval)
+ return;
+ retval = clk_enable(sport->clk_ipg);
+ if (retval) {
+ clk_disable(sport->clk_per);
+ return;
+ }
+
+ if (sport->port.sysrq)
+ locked = 0;
+ else if (oops_in_progress)
+ locked = spin_trylock_irqsave(&sport->port.lock, flags);
+ else
+ spin_lock_irqsave(&sport->port.lock, flags);
+
+ /*
+ * First, save UCR1/2/3 and then disable interrupts
+ */
+ imx_uart_ucrs_save(sport, &old_ucr);
+ ucr1 = old_ucr.ucr1;
+
+ if (imx_uart_is_imx1(sport))
+ ucr1 |= IMX1_UCR1_UARTCLKEN;
+ ucr1 |= UCR1_UARTEN;
+ ucr1 &= ~(UCR1_TXMPTYEN | UCR1_RRDYEN | UCR1_RTSDEN);
+
+ imx_uart_writel(sport, ucr1, UCR1);
+
+ imx_uart_writel(sport, old_ucr.ucr2 | UCR2_TXEN, UCR2);
+
+ uart_console_write(&sport->port, s, count, imx_uart_console_putchar);
+
+ /*
+ * Finally, wait for transmitter to become empty
+ * and restore UCR1/2/3
+ */
+ while (!(imx_uart_readl(sport, USR2) & USR2_TXDC));
+
+ imx_uart_ucrs_restore(sport, &old_ucr);
+
+ if (locked)
+ spin_unlock_irqrestore(&sport->port.lock, flags);
+
+ clk_disable(sport->clk_ipg);
+ clk_disable(sport->clk_per);
+}
+
+/*
+ * If the port was already initialised (eg, by a boot loader),
+ * try to determine the current setup.
+ */
+static void __init
+imx_uart_console_get_options(struct imx_port *sport, int *baud,
+ int *parity, int *bits)
+{
+
+ if (imx_uart_readl(sport, UCR1) & UCR1_UARTEN) {
+ /* ok, the port was enabled */
+ unsigned int ucr2, ubir, ubmr, uartclk;
+ unsigned int baud_raw;
+ unsigned int ucfr_rfdiv;
+
+ ucr2 = imx_uart_readl(sport, UCR2);
+
+ *parity = 'n';
+ if (ucr2 & UCR2_PREN) {
+ if (ucr2 & UCR2_PROE)
+ *parity = 'o';
+ else
+ *parity = 'e';
+ }
+
+ if (ucr2 & UCR2_WS)
+ *bits = 8;
+ else
+ *bits = 7;
+
+ ubir = imx_uart_readl(sport, UBIR) & 0xffff;
+ ubmr = imx_uart_readl(sport, UBMR) & 0xffff;
+
+ ucfr_rfdiv = (imx_uart_readl(sport, UFCR) & UFCR_RFDIV) >> 7;
+ if (ucfr_rfdiv == 6)
+ ucfr_rfdiv = 7;
+ else
+ ucfr_rfdiv = 6 - ucfr_rfdiv;
+
+ uartclk = clk_get_rate(sport->clk_per);
+ uartclk /= ucfr_rfdiv;
+
+ { /*
+ * The next code provides exact computation of
+ * baud_raw = round(((uartclk/16) * (ubir + 1)) / (ubmr + 1))
+ * without need of float support or long long division,
+ * which would be required to prevent 32bit arithmetic overflow
+ */
+ unsigned int mul = ubir + 1;
+ unsigned int div = 16 * (ubmr + 1);
+ unsigned int rem = uartclk % div;
+
+ baud_raw = (uartclk / div) * mul;
+ baud_raw += (rem * mul + div / 2) / div;
+ *baud = (baud_raw + 50) / 100 * 100;
+ }
+
+ if (*baud != baud_raw)
+ pr_info("Console IMX rounded baud rate from %d to %d\n",
+ baud_raw, *baud);
+ }
+}
+
+static int __init
+imx_uart_console_setup(struct console *co, char *options)
+{
+ struct imx_port *sport;
+ int baud = 9600;
+ int bits = 8;
+ int parity = 'n';
+ int flow = 'n';
+ int retval;
+
+ /*
+ * Check whether an invalid uart number has been specified, and
+ * if so, search for the first available port that does have
+ * console support.
+ */
+ if (co->index == -1 || co->index >= ARRAY_SIZE(imx_uart_ports))
+ co->index = 0;
+ sport = imx_uart_ports[co->index];
+ if (sport == NULL)
+ return -ENODEV;
+
+ /* For setting the registers, we only need to enable the ipg clock. */
+ retval = clk_prepare_enable(sport->clk_ipg);
+ if (retval)
+ goto error_console;
+
+ if (options)
+ uart_parse_options(options, &baud, &parity, &bits, &flow);
+ else
+ imx_uart_console_get_options(sport, &baud, &parity, &bits);
+
+ imx_uart_setup_ufcr(sport, TXTL_DEFAULT, RXTL_DEFAULT);
+
+ retval = uart_set_options(&sport->port, co, baud, parity, bits, flow);
+
+ clk_disable(sport->clk_ipg);
+ if (retval) {
+ clk_unprepare(sport->clk_ipg);
+ goto error_console;
+ }
+
+ retval = clk_prepare(sport->clk_per);
+ if (retval)
+ clk_disable_unprepare(sport->clk_ipg);
+
+error_console:
+ return retval;
+}
+
+static struct uart_driver imx_uart_uart_driver;
+static struct console imx_uart_console = {
+ .name = DEV_NAME,
+ .write = imx_uart_console_write,
+ .device = uart_console_device,
+ .setup = imx_uart_console_setup,
+ .flags = CON_PRINTBUFFER,
+ .index = -1,
+ .data = &imx_uart_uart_driver,
+};
+
+#define IMX_CONSOLE &imx_uart_console
+
+#ifdef CONFIG_OF
+static void imx_uart_console_early_putchar(struct uart_port *port, int ch)
+{
+ struct imx_port *sport = (struct imx_port *)port;
+
+ while (imx_uart_readl(sport, IMX21_UTS) & UTS_TXFULL)
+ cpu_relax();
+
+ imx_uart_writel(sport, ch, URTX0);
+}
+
+static void imx_uart_console_early_write(struct console *con, const char *s,
+ unsigned count)
+{
+ struct earlycon_device *dev = con->data;
+
+ uart_console_write(&dev->port, s, count, imx_uart_console_early_putchar);
+}
+
+static int __init
+imx_console_early_setup(struct earlycon_device *dev, const char *opt)
+{
+ if (!dev->port.membase)
+ return -ENODEV;
+
+ dev->con->write = imx_uart_console_early_write;
+
+ return 0;
+}
+OF_EARLYCON_DECLARE(ec_imx6q, "fsl,imx6q-uart", imx_console_early_setup);
+OF_EARLYCON_DECLARE(ec_imx21, "fsl,imx21-uart", imx_console_early_setup);
+#endif
+
+#else
+#define IMX_CONSOLE NULL
+#endif
+
+static struct uart_driver imx_uart_uart_driver = {
+ .owner = THIS_MODULE,
+ .driver_name = DRIVER_NAME,
+ .dev_name = DEV_NAME,
+ .major = SERIAL_IMX_MAJOR,
+ .minor = MINOR_START,
+ .nr = ARRAY_SIZE(imx_uart_ports),
+ .cons = IMX_CONSOLE,
+};
+
+#ifdef CONFIG_OF
+/*
+ * This function returns 1 iff pdev isn't a device instatiated by dt, 0 iff it
+ * could successfully get all information from dt or a negative errno.
+ */
+static int imx_uart_probe_dt(struct imx_port *sport,
+ struct platform_device *pdev)
+{
+ struct device_node *np = pdev->dev.of_node;
+ int ret;
+
+ sport->devdata = of_device_get_match_data(&pdev->dev);
+ if (!sport->devdata)
+ /* no device tree device */
+ return 1;
+
+ ret = of_alias_get_id(np, "serial");
+ if (ret < 0) {
+ dev_err(&pdev->dev, "failed to get alias id, errno %d\n", ret);
+ return ret;
+ }
+ sport->port.line = ret;
+
+ if (of_get_property(np, "uart-has-rtscts", NULL) ||
+ of_get_property(np, "fsl,uart-has-rtscts", NULL) /* deprecated */)
+ sport->have_rtscts = 1;
+
+ if (of_get_property(np, "fsl,dte-mode", NULL))
+ sport->dte_mode = 1;
+
+ if (of_get_property(np, "rts-gpios", NULL))
+ sport->have_rtsgpio = 1;
+
+ return 0;
+}
+#else
+static inline int imx_uart_probe_dt(struct imx_port *sport,
+ struct platform_device *pdev)
+{
+ return 1;
+}
+#endif
+
+static void imx_uart_probe_pdata(struct imx_port *sport,
+ struct platform_device *pdev)
+{
+ struct imxuart_platform_data *pdata = dev_get_platdata(&pdev->dev);
+
+ sport->port.line = pdev->id;
+ sport->devdata = (struct imx_uart_data *) pdev->id_entry->driver_data;
+
+ if (!pdata)
+ return;
+
+ if (pdata->flags & IMXUART_HAVE_RTSCTS)
+ sport->have_rtscts = 1;
+}
+
+static int imx_uart_probe(struct platform_device *pdev)
+{
+ struct imx_port *sport;
+ void __iomem *base;
+ int ret = 0;
+ u32 ucr1;
+ struct resource *res;
+ int txirq, rxirq, rtsirq;
+
+ sport = devm_kzalloc(&pdev->dev, sizeof(*sport), GFP_KERNEL);
+ if (!sport)
+ return -ENOMEM;
+
+ ret = imx_uart_probe_dt(sport, pdev);
+ if (ret > 0)
+ imx_uart_probe_pdata(sport, pdev);
+ else if (ret < 0)
+ return ret;
+
+ if (sport->port.line >= ARRAY_SIZE(imx_uart_ports)) {
+ dev_err(&pdev->dev, "serial%d out of range\n",
+ sport->port.line);
+ return -EINVAL;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ rxirq = platform_get_irq(pdev, 0);
+ txirq = platform_get_irq(pdev, 1);
+ rtsirq = platform_get_irq(pdev, 2);
+
+ sport->port.dev = &pdev->dev;
+ sport->port.mapbase = res->start;
+ sport->port.membase = base;
+ sport->port.type = PORT_IMX,
+ sport->port.iotype = UPIO_MEM;
+ sport->port.irq = rxirq;
+ sport->port.fifosize = 32;
+ sport->port.ops = &imx_uart_pops;
+ sport->port.rs485_config = imx_uart_rs485_config;
+ sport->port.flags = UPF_BOOT_AUTOCONF;
+ timer_setup(&sport->timer, imx_uart_timeout, 0);
+
+ sport->gpios = mctrl_gpio_init(&sport->port, 0);
+ if (IS_ERR(sport->gpios))
+ return PTR_ERR(sport->gpios);
+
+ sport->clk_ipg = devm_clk_get(&pdev->dev, "ipg");
+ if (IS_ERR(sport->clk_ipg)) {
+ ret = PTR_ERR(sport->clk_ipg);
+ dev_err(&pdev->dev, "failed to get ipg clk: %d\n", ret);
+ return ret;
+ }
+
+ sport->clk_per = devm_clk_get(&pdev->dev, "per");
+ if (IS_ERR(sport->clk_per)) {
+ ret = PTR_ERR(sport->clk_per);
+ dev_err(&pdev->dev, "failed to get per clk: %d\n", ret);
+ return ret;
+ }
+
+ sport->port.uartclk = clk_get_rate(sport->clk_per);
+
+ /* For register access, we only need to enable the ipg clock. */
+ ret = clk_prepare_enable(sport->clk_ipg);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to enable per clk: %d\n", ret);
+ return ret;
+ }
+
+ /* initialize shadow register values */
+ sport->ucr1 = readl(sport->port.membase + UCR1);
+ sport->ucr2 = readl(sport->port.membase + UCR2);
+ sport->ucr3 = readl(sport->port.membase + UCR3);
+ sport->ucr4 = readl(sport->port.membase + UCR4);
+ sport->ufcr = readl(sport->port.membase + UFCR);
+
+ uart_get_rs485_mode(&pdev->dev, &sport->port.rs485);
+
+ if (sport->port.rs485.flags & SER_RS485_ENABLED &&
+ (!sport->have_rtscts && !sport->have_rtsgpio))
+ dev_err(&pdev->dev, "no RTS control, disabling rs485\n");
+
+ /*
+ * If using the i.MX UART RTS/CTS control then the RTS (CTS_B)
+ * signal cannot be set low during transmission in case the
+ * receiver is off (limitation of the i.MX UART IP).
+ */
+ if (sport->port.rs485.flags & SER_RS485_ENABLED &&
+ sport->have_rtscts && !sport->have_rtsgpio &&
+ (!(sport->port.rs485.flags & SER_RS485_RTS_ON_SEND) &&
+ !(sport->port.rs485.flags & SER_RS485_RX_DURING_TX)))
+ dev_err(&pdev->dev,
+ "low-active RTS not possible when receiver is off, enabling receiver\n");
+
+ imx_uart_rs485_config(&sport->port, &sport->port.rs485);
+
+ /* Disable interrupts before requesting them */
+ ucr1 = imx_uart_readl(sport, UCR1);
+ ucr1 &= ~(UCR1_ADEN | UCR1_TRDYEN | UCR1_IDEN | UCR1_RRDYEN |
+ UCR1_TXMPTYEN | UCR1_RTSDEN);
+ imx_uart_writel(sport, ucr1, UCR1);
+
+ if (!imx_uart_is_imx1(sport) && sport->dte_mode) {
+ /*
+ * The DCEDTE bit changes the direction of DSR, DCD, DTR and RI
+ * and influences if UCR3_RI and UCR3_DCD changes the level of RI
+ * and DCD (when they are outputs) or enables the respective
+ * irqs. So set this bit early, i.e. before requesting irqs.
+ */
+ u32 ufcr = imx_uart_readl(sport, UFCR);
+ if (!(ufcr & UFCR_DCEDTE))
+ imx_uart_writel(sport, ufcr | UFCR_DCEDTE, UFCR);
+
+ /*
+ * Disable UCR3_RI and UCR3_DCD irqs. They are also not
+ * enabled later because they cannot be cleared
+ * (confirmed on i.MX25) which makes them unusable.
+ */
+ imx_uart_writel(sport,
+ IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP | UCR3_DSR,
+ UCR3);
+
+ } else {
+ u32 ucr3 = UCR3_DSR;
+ u32 ufcr = imx_uart_readl(sport, UFCR);
+ if (ufcr & UFCR_DCEDTE)
+ imx_uart_writel(sport, ufcr & ~UFCR_DCEDTE, UFCR);
+
+ if (!imx_uart_is_imx1(sport))
+ ucr3 |= IMX21_UCR3_RXDMUXSEL | UCR3_ADNIMP;
+ imx_uart_writel(sport, ucr3, UCR3);
+ }
+
+ clk_disable_unprepare(sport->clk_ipg);
+
+ /*
+ * Allocate the IRQ(s) i.MX1 has three interrupts whereas later
+ * chips only have one interrupt.
+ */
+ if (txirq > 0) {
+ ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_rxint, 0,
+ dev_name(&pdev->dev), sport);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to request rx irq: %d\n",
+ ret);
+ return ret;
+ }
+
+ ret = devm_request_irq(&pdev->dev, txirq, imx_uart_txint, 0,
+ dev_name(&pdev->dev), sport);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to request tx irq: %d\n",
+ ret);
+ return ret;
+ }
+
+ ret = devm_request_irq(&pdev->dev, rtsirq, imx_uart_rtsint, 0,
+ dev_name(&pdev->dev), sport);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to request rts irq: %d\n",
+ ret);
+ return ret;
+ }
+ } else {
+ ret = devm_request_irq(&pdev->dev, rxirq, imx_uart_int, 0,
+ dev_name(&pdev->dev), sport);
+ if (ret) {
+ dev_err(&pdev->dev, "failed to request irq: %d\n", ret);
+ return ret;
+ }
+ }
+
+ imx_uart_ports[sport->port.line] = sport;
+
+ platform_set_drvdata(pdev, sport);
+
+ return uart_add_one_port(&imx_uart_uart_driver, &sport->port);
+}
+
+static int imx_uart_remove(struct platform_device *pdev)
+{
+ struct imx_port *sport = platform_get_drvdata(pdev);
+
+ return uart_remove_one_port(&imx_uart_uart_driver, &sport->port);
+}
+
+static void imx_uart_restore_context(struct imx_port *sport)
+{
+ if (!sport->context_saved)
+ return;
+
+ imx_uart_writel(sport, sport->saved_reg[4], UFCR);
+ imx_uart_writel(sport, sport->saved_reg[5], UESC);
+ imx_uart_writel(sport, sport->saved_reg[6], UTIM);
+ imx_uart_writel(sport, sport->saved_reg[7], UBIR);
+ imx_uart_writel(sport, sport->saved_reg[8], UBMR);
+ imx_uart_writel(sport, sport->saved_reg[9], IMX21_UTS);
+ imx_uart_writel(sport, sport->saved_reg[0], UCR1);
+ imx_uart_writel(sport, sport->saved_reg[1] | UCR2_SRST, UCR2);
+ imx_uart_writel(sport, sport->saved_reg[2], UCR3);
+ imx_uart_writel(sport, sport->saved_reg[3], UCR4);
+ sport->context_saved = false;
+}
+
+static void imx_uart_save_context(struct imx_port *sport)
+{
+ /* Save necessary regs */
+ sport->saved_reg[0] = imx_uart_readl(sport, UCR1);
+ sport->saved_reg[1] = imx_uart_readl(sport, UCR2);
+ sport->saved_reg[2] = imx_uart_readl(sport, UCR3);
+ sport->saved_reg[3] = imx_uart_readl(sport, UCR4);
+ sport->saved_reg[4] = imx_uart_readl(sport, UFCR);
+ sport->saved_reg[5] = imx_uart_readl(sport, UESC);
+ sport->saved_reg[6] = imx_uart_readl(sport, UTIM);
+ sport->saved_reg[7] = imx_uart_readl(sport, UBIR);
+ sport->saved_reg[8] = imx_uart_readl(sport, UBMR);
+ sport->saved_reg[9] = imx_uart_readl(sport, IMX21_UTS);
+ sport->context_saved = true;
+}
+
+static void imx_uart_enable_wakeup(struct imx_port *sport, bool on)
+{
+ u32 ucr3;
+
+ ucr3 = imx_uart_readl(sport, UCR3);
+ if (on) {
+ imx_uart_writel(sport, USR1_AWAKE, USR1);
+ ucr3 |= UCR3_AWAKEN;
+ } else {
+ ucr3 &= ~UCR3_AWAKEN;
+ }
+ imx_uart_writel(sport, ucr3, UCR3);
+
+ if (sport->have_rtscts) {
+ u32 ucr1 = imx_uart_readl(sport, UCR1);
+ if (on)
+ ucr1 |= UCR1_RTSDEN;
+ else
+ ucr1 &= ~UCR1_RTSDEN;
+ imx_uart_writel(sport, ucr1, UCR1);
+ }
+}
+
+static int imx_uart_suspend_noirq(struct device *dev)
+{
+ struct imx_port *sport = dev_get_drvdata(dev);
+
+ imx_uart_save_context(sport);
+
+ clk_disable(sport->clk_ipg);
+
+ return 0;
+}
+
+static int imx_uart_resume_noirq(struct device *dev)
+{
+ struct imx_port *sport = dev_get_drvdata(dev);
+ int ret;
+
+ ret = clk_enable(sport->clk_ipg);
+ if (ret)
+ return ret;
+
+ imx_uart_restore_context(sport);
+
+ return 0;
+}
+
+static int imx_uart_suspend(struct device *dev)
+{
+ struct imx_port *sport = dev_get_drvdata(dev);
+ int ret;
+
+ uart_suspend_port(&imx_uart_uart_driver, &sport->port);
+ disable_irq(sport->port.irq);
+
+ ret = clk_prepare_enable(sport->clk_ipg);
+ if (ret)
+ return ret;
+
+ /* enable wakeup from i.MX UART */
+ imx_uart_enable_wakeup(sport, true);
+
+ return 0;
+}
+
+static int imx_uart_resume(struct device *dev)
+{
+ struct imx_port *sport = dev_get_drvdata(dev);
+
+ /* disable wakeup from i.MX UART */
+ imx_uart_enable_wakeup(sport, false);
+
+ uart_resume_port(&imx_uart_uart_driver, &sport->port);
+ enable_irq(sport->port.irq);
+
+ clk_disable_unprepare(sport->clk_ipg);
+
+ return 0;
+}
+
+static int imx_uart_freeze(struct device *dev)
+{
+ struct imx_port *sport = dev_get_drvdata(dev);
+
+ uart_suspend_port(&imx_uart_uart_driver, &sport->port);
+
+ return clk_prepare_enable(sport->clk_ipg);
+}
+
+static int imx_uart_thaw(struct device *dev)
+{
+ struct imx_port *sport = dev_get_drvdata(dev);
+
+ uart_resume_port(&imx_uart_uart_driver, &sport->port);
+
+ clk_disable_unprepare(sport->clk_ipg);
+
+ return 0;
+}
+
+static const struct dev_pm_ops imx_uart_pm_ops = {
+ .suspend_noirq = imx_uart_suspend_noirq,
+ .resume_noirq = imx_uart_resume_noirq,
+ .freeze_noirq = imx_uart_suspend_noirq,
+ .restore_noirq = imx_uart_resume_noirq,
+ .suspend = imx_uart_suspend,
+ .resume = imx_uart_resume,
+ .freeze = imx_uart_freeze,
+ .thaw = imx_uart_thaw,
+ .restore = imx_uart_thaw,
+};
+
+static struct platform_driver imx_uart_platform_driver = {
+ .probe = imx_uart_probe,
+ .remove = imx_uart_remove,
+
+ .id_table = imx_uart_devtype,
+ .driver = {
+ .name = "imx-uart",
+ .of_match_table = imx_uart_dt_ids,
+ .pm = &imx_uart_pm_ops,
+ },
+};
+
+static int __init imx_uart_init(void)
+{
+ int ret = uart_register_driver(&imx_uart_uart_driver);
+
+ if (ret)
+ return ret;
+
+ ret = platform_driver_register(&imx_uart_platform_driver);
+ if (ret != 0)
+ uart_unregister_driver(&imx_uart_uart_driver);
+
+ return ret;
+}
+
+static void __exit imx_uart_exit(void)
+{
+ platform_driver_unregister(&imx_uart_platform_driver);
+ uart_unregister_driver(&imx_uart_uart_driver);
+}
+
+module_init(imx_uart_init);
+module_exit(imx_uart_exit);
+
+MODULE_AUTHOR("Sascha Hauer");
+MODULE_DESCRIPTION("IMX generic serial port driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:imx-uart");