v4.19.13 snapshot.
diff --git a/drivers/i2c/busses/i2c-rcar.c b/drivers/i2c/busses/i2c-rcar.c
new file mode 100644
index 0000000..254e621
--- /dev/null
+++ b/drivers/i2c/busses/i2c-rcar.c
@@ -0,0 +1,1033 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for the Renesas R-Car I2C unit
+ *
+ * Copyright (C) 2014-15 Wolfram Sang <wsa@sang-engineering.com>
+ * Copyright (C) 2011-2015 Renesas Electronics Corporation
+ *
+ * Copyright (C) 2012-14 Renesas Solutions Corp.
+ * Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
+ *
+ * This file is based on the drivers/i2c/busses/i2c-sh7760.c
+ * (c) 2005-2008 MSC Vertriebsges.m.b.H, Manuel Lauss <mlau@msc-ge.com>
+ */
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/i2c.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
+#include <linux/reset.h>
+#include <linux/slab.h>
+
+/* register offsets */
+#define ICSCR 0x00 /* slave ctrl */
+#define ICMCR 0x04 /* master ctrl */
+#define ICSSR 0x08 /* slave status */
+#define ICMSR 0x0C /* master status */
+#define ICSIER 0x10 /* slave irq enable */
+#define ICMIER 0x14 /* master irq enable */
+#define ICCCR 0x18 /* clock dividers */
+#define ICSAR 0x1C /* slave address */
+#define ICMAR 0x20 /* master address */
+#define ICRXTX 0x24 /* data port */
+#define ICDMAER 0x3c /* DMA enable */
+#define ICFBSCR 0x38 /* first bit setup cycle */
+
+/* ICSCR */
+#define SDBS (1 << 3) /* slave data buffer select */
+#define SIE (1 << 2) /* slave interface enable */
+#define GCAE (1 << 1) /* general call address enable */
+#define FNA (1 << 0) /* forced non acknowledgment */
+
+/* ICMCR */
+#define MDBS (1 << 7) /* non-fifo mode switch */
+#define FSCL (1 << 6) /* override SCL pin */
+#define FSDA (1 << 5) /* override SDA pin */
+#define OBPC (1 << 4) /* override pins */
+#define MIE (1 << 3) /* master if enable */
+#define TSBE (1 << 2)
+#define FSB (1 << 1) /* force stop bit */
+#define ESG (1 << 0) /* enable start bit gen */
+
+/* ICSSR (also for ICSIER) */
+#define GCAR (1 << 6) /* general call received */
+#define STM (1 << 5) /* slave transmit mode */
+#define SSR (1 << 4) /* stop received */
+#define SDE (1 << 3) /* slave data empty */
+#define SDT (1 << 2) /* slave data transmitted */
+#define SDR (1 << 1) /* slave data received */
+#define SAR (1 << 0) /* slave addr received */
+
+/* ICMSR (also for ICMIE) */
+#define MNR (1 << 6) /* nack received */
+#define MAL (1 << 5) /* arbitration lost */
+#define MST (1 << 4) /* sent a stop */
+#define MDE (1 << 3)
+#define MDT (1 << 2)
+#define MDR (1 << 1)
+#define MAT (1 << 0) /* slave addr xfer done */
+
+/* ICDMAER */
+#define RSDMAE (1 << 3) /* DMA Slave Received Enable */
+#define TSDMAE (1 << 2) /* DMA Slave Transmitted Enable */
+#define RMDMAE (1 << 1) /* DMA Master Received Enable */
+#define TMDMAE (1 << 0) /* DMA Master Transmitted Enable */
+
+/* ICFBSCR */
+#define TCYC06 0x04 /* 6*Tcyc delay 1st bit between SDA and SCL */
+#define TCYC17 0x0f /* 17*Tcyc delay 1st bit between SDA and SCL */
+
+
+#define RCAR_BUS_PHASE_START (MDBS | MIE | ESG)
+#define RCAR_BUS_PHASE_DATA (MDBS | MIE)
+#define RCAR_BUS_MASK_DATA (~(ESG | FSB) & 0xFF)
+#define RCAR_BUS_PHASE_STOP (MDBS | MIE | FSB)
+
+#define RCAR_IRQ_SEND (MNR | MAL | MST | MAT | MDE)
+#define RCAR_IRQ_RECV (MNR | MAL | MST | MAT | MDR)
+#define RCAR_IRQ_STOP (MST)
+
+#define RCAR_IRQ_ACK_SEND (~(MAT | MDE) & 0x7F)
+#define RCAR_IRQ_ACK_RECV (~(MAT | MDR) & 0x7F)
+
+#define ID_LAST_MSG (1 << 0)
+#define ID_FIRST_MSG (1 << 1)
+#define ID_DONE (1 << 2)
+#define ID_ARBLOST (1 << 3)
+#define ID_NACK (1 << 4)
+/* persistent flags */
+#define ID_P_REP_AFTER_RD BIT(29)
+#define ID_P_NO_RXDMA BIT(30) /* HW forbids RXDMA sometimes */
+#define ID_P_PM_BLOCKED BIT(31)
+#define ID_P_MASK GENMASK(31, 29)
+
+enum rcar_i2c_type {
+ I2C_RCAR_GEN1,
+ I2C_RCAR_GEN2,
+ I2C_RCAR_GEN3,
+};
+
+struct rcar_i2c_priv {
+ void __iomem *io;
+ struct i2c_adapter adap;
+ struct i2c_msg *msg;
+ int msgs_left;
+ struct clk *clk;
+
+ wait_queue_head_t wait;
+
+ int pos;
+ u32 icccr;
+ u32 flags;
+ u8 recovery_icmcr; /* protected by adapter lock */
+ enum rcar_i2c_type devtype;
+ struct i2c_client *slave;
+
+ struct resource *res;
+ struct dma_chan *dma_tx;
+ struct dma_chan *dma_rx;
+ struct scatterlist sg;
+ enum dma_data_direction dma_direction;
+
+ struct reset_control *rstc;
+};
+
+#define rcar_i2c_priv_to_dev(p) ((p)->adap.dev.parent)
+#define rcar_i2c_is_recv(p) ((p)->msg->flags & I2C_M_RD)
+
+#define LOOP_TIMEOUT 1024
+
+
+static void rcar_i2c_write(struct rcar_i2c_priv *priv, int reg, u32 val)
+{
+ writel(val, priv->io + reg);
+}
+
+static u32 rcar_i2c_read(struct rcar_i2c_priv *priv, int reg)
+{
+ return readl(priv->io + reg);
+}
+
+static int rcar_i2c_get_scl(struct i2c_adapter *adap)
+{
+ struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
+
+ return !!(rcar_i2c_read(priv, ICMCR) & FSCL);
+
+};
+
+static void rcar_i2c_set_scl(struct i2c_adapter *adap, int val)
+{
+ struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
+
+ if (val)
+ priv->recovery_icmcr |= FSCL;
+ else
+ priv->recovery_icmcr &= ~FSCL;
+
+ rcar_i2c_write(priv, ICMCR, priv->recovery_icmcr);
+};
+
+static void rcar_i2c_set_sda(struct i2c_adapter *adap, int val)
+{
+ struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
+
+ if (val)
+ priv->recovery_icmcr |= FSDA;
+ else
+ priv->recovery_icmcr &= ~FSDA;
+
+ rcar_i2c_write(priv, ICMCR, priv->recovery_icmcr);
+};
+
+static int rcar_i2c_get_bus_free(struct i2c_adapter *adap)
+{
+ struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
+
+ return !(rcar_i2c_read(priv, ICMCR) & FSDA);
+
+};
+
+static struct i2c_bus_recovery_info rcar_i2c_bri = {
+ .get_scl = rcar_i2c_get_scl,
+ .set_scl = rcar_i2c_set_scl,
+ .set_sda = rcar_i2c_set_sda,
+ .get_bus_free = rcar_i2c_get_bus_free,
+ .recover_bus = i2c_generic_scl_recovery,
+};
+static void rcar_i2c_init(struct rcar_i2c_priv *priv)
+{
+ /* reset master mode */
+ rcar_i2c_write(priv, ICMIER, 0);
+ rcar_i2c_write(priv, ICMCR, MDBS);
+ rcar_i2c_write(priv, ICMSR, 0);
+ /* start clock */
+ rcar_i2c_write(priv, ICCCR, priv->icccr);
+}
+
+static int rcar_i2c_bus_barrier(struct rcar_i2c_priv *priv)
+{
+ int i;
+
+ for (i = 0; i < LOOP_TIMEOUT; i++) {
+ /* make sure that bus is not busy */
+ if (!(rcar_i2c_read(priv, ICMCR) & FSDA))
+ return 0;
+ udelay(1);
+ }
+
+ /* Waiting did not help, try to recover */
+ priv->recovery_icmcr = MDBS | OBPC | FSDA | FSCL;
+ return i2c_recover_bus(&priv->adap);
+}
+
+static int rcar_i2c_clock_calculate(struct rcar_i2c_priv *priv, struct i2c_timings *t)
+{
+ u32 scgd, cdf, round, ick, sum, scl, cdf_width;
+ unsigned long rate;
+ struct device *dev = rcar_i2c_priv_to_dev(priv);
+
+ /* Fall back to previously used values if not supplied */
+ t->bus_freq_hz = t->bus_freq_hz ?: 100000;
+ t->scl_fall_ns = t->scl_fall_ns ?: 35;
+ t->scl_rise_ns = t->scl_rise_ns ?: 200;
+ t->scl_int_delay_ns = t->scl_int_delay_ns ?: 50;
+
+ switch (priv->devtype) {
+ case I2C_RCAR_GEN1:
+ cdf_width = 2;
+ break;
+ case I2C_RCAR_GEN2:
+ case I2C_RCAR_GEN3:
+ cdf_width = 3;
+ break;
+ default:
+ dev_err(dev, "device type error\n");
+ return -EIO;
+ }
+
+ /*
+ * calculate SCL clock
+ * see
+ * ICCCR
+ *
+ * ick = clkp / (1 + CDF)
+ * SCL = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick])
+ *
+ * ick : I2C internal clock < 20 MHz
+ * ticf : I2C SCL falling time
+ * tr : I2C SCL rising time
+ * intd : LSI internal delay
+ * clkp : peripheral_clk
+ * F[] : integer up-valuation
+ */
+ rate = clk_get_rate(priv->clk);
+ cdf = rate / 20000000;
+ if (cdf >= 1U << cdf_width) {
+ dev_err(dev, "Input clock %lu too high\n", rate);
+ return -EIO;
+ }
+ ick = rate / (cdf + 1);
+
+ /*
+ * it is impossible to calculate large scale
+ * number on u32. separate it
+ *
+ * F[(ticf + tr + intd) * ick] with sum = (ticf + tr + intd)
+ * = F[sum * ick / 1000000000]
+ * = F[(ick / 1000000) * sum / 1000]
+ */
+ sum = t->scl_fall_ns + t->scl_rise_ns + t->scl_int_delay_ns;
+ round = (ick + 500000) / 1000000 * sum;
+ round = (round + 500) / 1000;
+
+ /*
+ * SCL = ick / (20 + SCGD * 8 + F[(ticf + tr + intd) * ick])
+ *
+ * Calculation result (= SCL) should be less than
+ * bus_speed for hardware safety
+ *
+ * We could use something along the lines of
+ * div = ick / (bus_speed + 1) + 1;
+ * scgd = (div - 20 - round + 7) / 8;
+ * scl = ick / (20 + (scgd * 8) + round);
+ * (not fully verified) but that would get pretty involved
+ */
+ for (scgd = 0; scgd < 0x40; scgd++) {
+ scl = ick / (20 + (scgd * 8) + round);
+ if (scl <= t->bus_freq_hz)
+ goto scgd_find;
+ }
+ dev_err(dev, "it is impossible to calculate best SCL\n");
+ return -EIO;
+
+scgd_find:
+ dev_dbg(dev, "clk %d/%d(%lu), round %u, CDF:0x%x, SCGD: 0x%x\n",
+ scl, t->bus_freq_hz, clk_get_rate(priv->clk), round, cdf, scgd);
+
+ /* keep icccr value */
+ priv->icccr = scgd << cdf_width | cdf;
+
+ return 0;
+}
+
+static void rcar_i2c_prepare_msg(struct rcar_i2c_priv *priv)
+{
+ int read = !!rcar_i2c_is_recv(priv);
+
+ priv->pos = 0;
+ if (priv->msgs_left == 1)
+ priv->flags |= ID_LAST_MSG;
+
+ rcar_i2c_write(priv, ICMAR, i2c_8bit_addr_from_msg(priv->msg));
+ /*
+ * We don't have a test case but the HW engineers say that the write order
+ * of ICMSR and ICMCR depends on whether we issue START or REP_START. Since
+ * it didn't cause a drawback for me, let's rather be safe than sorry.
+ */
+ if (priv->flags & ID_FIRST_MSG) {
+ rcar_i2c_write(priv, ICMSR, 0);
+ rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
+ } else {
+ if (priv->flags & ID_P_REP_AFTER_RD)
+ priv->flags &= ~ID_P_REP_AFTER_RD;
+ else
+ rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
+ rcar_i2c_write(priv, ICMSR, 0);
+ }
+ rcar_i2c_write(priv, ICMIER, read ? RCAR_IRQ_RECV : RCAR_IRQ_SEND);
+}
+
+static void rcar_i2c_next_msg(struct rcar_i2c_priv *priv)
+{
+ priv->msg++;
+ priv->msgs_left--;
+ priv->flags &= ID_P_MASK;
+ rcar_i2c_prepare_msg(priv);
+}
+
+/*
+ * interrupt functions
+ */
+static void rcar_i2c_dma_unmap(struct rcar_i2c_priv *priv)
+{
+ struct dma_chan *chan = priv->dma_direction == DMA_FROM_DEVICE
+ ? priv->dma_rx : priv->dma_tx;
+
+ /* Disable DMA Master Received/Transmitted */
+ rcar_i2c_write(priv, ICDMAER, 0);
+
+ /* Reset default delay */
+ rcar_i2c_write(priv, ICFBSCR, TCYC06);
+
+ dma_unmap_single(chan->device->dev, sg_dma_address(&priv->sg),
+ sg_dma_len(&priv->sg), priv->dma_direction);
+
+ /* Gen3 can only do one RXDMA per transfer and we just completed it */
+ if (priv->devtype == I2C_RCAR_GEN3 &&
+ priv->dma_direction == DMA_FROM_DEVICE)
+ priv->flags |= ID_P_NO_RXDMA;
+
+ priv->dma_direction = DMA_NONE;
+}
+
+static void rcar_i2c_cleanup_dma(struct rcar_i2c_priv *priv)
+{
+ if (priv->dma_direction == DMA_NONE)
+ return;
+ else if (priv->dma_direction == DMA_FROM_DEVICE)
+ dmaengine_terminate_all(priv->dma_rx);
+ else if (priv->dma_direction == DMA_TO_DEVICE)
+ dmaengine_terminate_all(priv->dma_tx);
+
+ rcar_i2c_dma_unmap(priv);
+}
+
+static void rcar_i2c_dma_callback(void *data)
+{
+ struct rcar_i2c_priv *priv = data;
+
+ priv->pos += sg_dma_len(&priv->sg);
+
+ rcar_i2c_dma_unmap(priv);
+}
+
+static void rcar_i2c_dma(struct rcar_i2c_priv *priv)
+{
+ struct device *dev = rcar_i2c_priv_to_dev(priv);
+ struct i2c_msg *msg = priv->msg;
+ bool read = msg->flags & I2C_M_RD;
+ enum dma_data_direction dir = read ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
+ struct dma_chan *chan = read ? priv->dma_rx : priv->dma_tx;
+ struct dma_async_tx_descriptor *txdesc;
+ dma_addr_t dma_addr;
+ dma_cookie_t cookie;
+ unsigned char *buf;
+ int len;
+
+ /* Do various checks to see if DMA is feasible at all */
+ if (IS_ERR(chan) || msg->len < 8 || !(msg->flags & I2C_M_DMA_SAFE) ||
+ (read && priv->flags & ID_P_NO_RXDMA))
+ return;
+
+ if (read) {
+ /*
+ * The last two bytes needs to be fetched using PIO in
+ * order for the STOP phase to work.
+ */
+ buf = priv->msg->buf;
+ len = priv->msg->len - 2;
+ } else {
+ /*
+ * First byte in message was sent using PIO.
+ */
+ buf = priv->msg->buf + 1;
+ len = priv->msg->len - 1;
+ }
+
+ dma_addr = dma_map_single(chan->device->dev, buf, len, dir);
+ if (dma_mapping_error(chan->device->dev, dma_addr)) {
+ dev_dbg(dev, "dma map failed, using PIO\n");
+ return;
+ }
+
+ sg_dma_len(&priv->sg) = len;
+ sg_dma_address(&priv->sg) = dma_addr;
+
+ priv->dma_direction = dir;
+
+ txdesc = dmaengine_prep_slave_sg(chan, &priv->sg, 1,
+ read ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV,
+ DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
+ if (!txdesc) {
+ dev_dbg(dev, "dma prep slave sg failed, using PIO\n");
+ rcar_i2c_cleanup_dma(priv);
+ return;
+ }
+
+ txdesc->callback = rcar_i2c_dma_callback;
+ txdesc->callback_param = priv;
+
+ cookie = dmaengine_submit(txdesc);
+ if (dma_submit_error(cookie)) {
+ dev_dbg(dev, "submitting dma failed, using PIO\n");
+ rcar_i2c_cleanup_dma(priv);
+ return;
+ }
+
+ /* Set delay for DMA operations */
+ rcar_i2c_write(priv, ICFBSCR, TCYC17);
+
+ /* Enable DMA Master Received/Transmitted */
+ if (read)
+ rcar_i2c_write(priv, ICDMAER, RMDMAE);
+ else
+ rcar_i2c_write(priv, ICDMAER, TMDMAE);
+
+ dma_async_issue_pending(chan);
+}
+
+static void rcar_i2c_irq_send(struct rcar_i2c_priv *priv, u32 msr)
+{
+ struct i2c_msg *msg = priv->msg;
+
+ /* FIXME: sometimes, unknown interrupt happened. Do nothing */
+ if (!(msr & MDE))
+ return;
+
+ if (priv->pos < msg->len) {
+ /*
+ * Prepare next data to ICRXTX register.
+ * This data will go to _SHIFT_ register.
+ *
+ * *
+ * [ICRXTX] -> [SHIFT] -> [I2C bus]
+ */
+ rcar_i2c_write(priv, ICRXTX, msg->buf[priv->pos]);
+ priv->pos++;
+
+ /*
+ * Try to use DMA to transmit the rest of the data if
+ * address transfer phase just finished.
+ */
+ if (msr & MAT)
+ rcar_i2c_dma(priv);
+ } else {
+ /*
+ * The last data was pushed to ICRXTX on _PREV_ empty irq.
+ * It is on _SHIFT_ register, and will sent to I2C bus.
+ *
+ * *
+ * [ICRXTX] -> [SHIFT] -> [I2C bus]
+ */
+
+ if (priv->flags & ID_LAST_MSG) {
+ /*
+ * If current msg is the _LAST_ msg,
+ * prepare stop condition here.
+ * ID_DONE will be set on STOP irq.
+ */
+ rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
+ } else {
+ rcar_i2c_next_msg(priv);
+ return;
+ }
+ }
+
+ rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_SEND);
+}
+
+static void rcar_i2c_irq_recv(struct rcar_i2c_priv *priv, u32 msr)
+{
+ struct i2c_msg *msg = priv->msg;
+
+ /* FIXME: sometimes, unknown interrupt happened. Do nothing */
+ if (!(msr & MDR))
+ return;
+
+ if (msr & MAT) {
+ /*
+ * Address transfer phase finished, but no data at this point.
+ * Try to use DMA to receive data.
+ */
+ rcar_i2c_dma(priv);
+ } else if (priv->pos < msg->len) {
+ /* get received data */
+ msg->buf[priv->pos] = rcar_i2c_read(priv, ICRXTX);
+ priv->pos++;
+ }
+
+ /* If next received data is the _LAST_, go to new phase. */
+ if (priv->pos + 1 == msg->len) {
+ if (priv->flags & ID_LAST_MSG) {
+ rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_STOP);
+ } else {
+ rcar_i2c_write(priv, ICMCR, RCAR_BUS_PHASE_START);
+ priv->flags |= ID_P_REP_AFTER_RD;
+ }
+ }
+
+ if (priv->pos == msg->len && !(priv->flags & ID_LAST_MSG))
+ rcar_i2c_next_msg(priv);
+ else
+ rcar_i2c_write(priv, ICMSR, RCAR_IRQ_ACK_RECV);
+}
+
+static bool rcar_i2c_slave_irq(struct rcar_i2c_priv *priv)
+{
+ u32 ssr_raw, ssr_filtered;
+ u8 value;
+
+ ssr_raw = rcar_i2c_read(priv, ICSSR) & 0xff;
+ ssr_filtered = ssr_raw & rcar_i2c_read(priv, ICSIER);
+
+ if (!ssr_filtered)
+ return false;
+
+ /* address detected */
+ if (ssr_filtered & SAR) {
+ /* read or write request */
+ if (ssr_raw & STM) {
+ i2c_slave_event(priv->slave, I2C_SLAVE_READ_REQUESTED, &value);
+ rcar_i2c_write(priv, ICRXTX, value);
+ rcar_i2c_write(priv, ICSIER, SDE | SSR | SAR);
+ } else {
+ i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_REQUESTED, &value);
+ rcar_i2c_read(priv, ICRXTX); /* dummy read */
+ rcar_i2c_write(priv, ICSIER, SDR | SSR | SAR);
+ }
+
+ rcar_i2c_write(priv, ICSSR, ~SAR & 0xff);
+ }
+
+ /* master sent stop */
+ if (ssr_filtered & SSR) {
+ i2c_slave_event(priv->slave, I2C_SLAVE_STOP, &value);
+ rcar_i2c_write(priv, ICSIER, SAR | SSR);
+ rcar_i2c_write(priv, ICSSR, ~SSR & 0xff);
+ }
+
+ /* master wants to write to us */
+ if (ssr_filtered & SDR) {
+ int ret;
+
+ value = rcar_i2c_read(priv, ICRXTX);
+ ret = i2c_slave_event(priv->slave, I2C_SLAVE_WRITE_RECEIVED, &value);
+ /* Send NACK in case of error */
+ rcar_i2c_write(priv, ICSCR, SIE | SDBS | (ret < 0 ? FNA : 0));
+ rcar_i2c_write(priv, ICSSR, ~SDR & 0xff);
+ }
+
+ /* master wants to read from us */
+ if (ssr_filtered & SDE) {
+ i2c_slave_event(priv->slave, I2C_SLAVE_READ_PROCESSED, &value);
+ rcar_i2c_write(priv, ICRXTX, value);
+ rcar_i2c_write(priv, ICSSR, ~SDE & 0xff);
+ }
+
+ return true;
+}
+
+static irqreturn_t rcar_i2c_irq(int irq, void *ptr)
+{
+ struct rcar_i2c_priv *priv = ptr;
+ u32 msr, val;
+
+ /* Clear START or STOP immediately, except for REPSTART after read */
+ if (likely(!(priv->flags & ID_P_REP_AFTER_RD))) {
+ val = rcar_i2c_read(priv, ICMCR);
+ rcar_i2c_write(priv, ICMCR, val & RCAR_BUS_MASK_DATA);
+ }
+
+ msr = rcar_i2c_read(priv, ICMSR);
+
+ /* Only handle interrupts that are currently enabled */
+ msr &= rcar_i2c_read(priv, ICMIER);
+ if (!msr) {
+ if (rcar_i2c_slave_irq(priv))
+ return IRQ_HANDLED;
+
+ return IRQ_NONE;
+ }
+
+ /* Arbitration lost */
+ if (msr & MAL) {
+ priv->flags |= ID_DONE | ID_ARBLOST;
+ goto out;
+ }
+
+ /* Nack */
+ if (msr & MNR) {
+ /* HW automatically sends STOP after received NACK */
+ rcar_i2c_write(priv, ICMIER, RCAR_IRQ_STOP);
+ priv->flags |= ID_NACK;
+ goto out;
+ }
+
+ /* Stop */
+ if (msr & MST) {
+ priv->msgs_left--; /* The last message also made it */
+ priv->flags |= ID_DONE;
+ goto out;
+ }
+
+ if (rcar_i2c_is_recv(priv))
+ rcar_i2c_irq_recv(priv, msr);
+ else
+ rcar_i2c_irq_send(priv, msr);
+
+out:
+ if (priv->flags & ID_DONE) {
+ rcar_i2c_write(priv, ICMIER, 0);
+ rcar_i2c_write(priv, ICMSR, 0);
+ wake_up(&priv->wait);
+ }
+
+ return IRQ_HANDLED;
+}
+
+static struct dma_chan *rcar_i2c_request_dma_chan(struct device *dev,
+ enum dma_transfer_direction dir,
+ dma_addr_t port_addr)
+{
+ struct dma_chan *chan;
+ struct dma_slave_config cfg;
+ char *chan_name = dir == DMA_MEM_TO_DEV ? "tx" : "rx";
+ int ret;
+
+ chan = dma_request_chan(dev, chan_name);
+ if (IS_ERR(chan)) {
+ dev_dbg(dev, "request_channel failed for %s (%ld)\n",
+ chan_name, PTR_ERR(chan));
+ return chan;
+ }
+
+ memset(&cfg, 0, sizeof(cfg));
+ cfg.direction = dir;
+ if (dir == DMA_MEM_TO_DEV) {
+ cfg.dst_addr = port_addr;
+ cfg.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ } else {
+ cfg.src_addr = port_addr;
+ cfg.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+ }
+
+ ret = dmaengine_slave_config(chan, &cfg);
+ if (ret) {
+ dev_dbg(dev, "slave_config failed for %s (%d)\n",
+ chan_name, ret);
+ dma_release_channel(chan);
+ return ERR_PTR(ret);
+ }
+
+ dev_dbg(dev, "got DMA channel for %s\n", chan_name);
+ return chan;
+}
+
+static void rcar_i2c_request_dma(struct rcar_i2c_priv *priv,
+ struct i2c_msg *msg)
+{
+ struct device *dev = rcar_i2c_priv_to_dev(priv);
+ bool read;
+ struct dma_chan *chan;
+ enum dma_transfer_direction dir;
+
+ read = msg->flags & I2C_M_RD;
+
+ chan = read ? priv->dma_rx : priv->dma_tx;
+ if (PTR_ERR(chan) != -EPROBE_DEFER)
+ return;
+
+ dir = read ? DMA_DEV_TO_MEM : DMA_MEM_TO_DEV;
+ chan = rcar_i2c_request_dma_chan(dev, dir, priv->res->start + ICRXTX);
+
+ if (read)
+ priv->dma_rx = chan;
+ else
+ priv->dma_tx = chan;
+}
+
+static void rcar_i2c_release_dma(struct rcar_i2c_priv *priv)
+{
+ if (!IS_ERR(priv->dma_tx)) {
+ dma_release_channel(priv->dma_tx);
+ priv->dma_tx = ERR_PTR(-EPROBE_DEFER);
+ }
+
+ if (!IS_ERR(priv->dma_rx)) {
+ dma_release_channel(priv->dma_rx);
+ priv->dma_rx = ERR_PTR(-EPROBE_DEFER);
+ }
+}
+
+/* I2C is a special case, we need to poll the status of a reset */
+static int rcar_i2c_do_reset(struct rcar_i2c_priv *priv)
+{
+ int i, ret;
+
+ ret = reset_control_reset(priv->rstc);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < LOOP_TIMEOUT; i++) {
+ ret = reset_control_status(priv->rstc);
+ if (ret == 0)
+ return 0;
+ udelay(1);
+ }
+
+ return -ETIMEDOUT;
+}
+
+static int rcar_i2c_master_xfer(struct i2c_adapter *adap,
+ struct i2c_msg *msgs,
+ int num)
+{
+ struct rcar_i2c_priv *priv = i2c_get_adapdata(adap);
+ struct device *dev = rcar_i2c_priv_to_dev(priv);
+ int i, ret;
+ long time_left;
+
+ pm_runtime_get_sync(dev);
+
+ /* Check bus state before init otherwise bus busy info will be lost */
+ ret = rcar_i2c_bus_barrier(priv);
+ if (ret < 0)
+ goto out;
+
+ /* Gen3 needs a reset before allowing RXDMA once */
+ if (priv->devtype == I2C_RCAR_GEN3) {
+ priv->flags |= ID_P_NO_RXDMA;
+ if (!IS_ERR(priv->rstc)) {
+ ret = rcar_i2c_do_reset(priv);
+ if (ret == 0)
+ priv->flags &= ~ID_P_NO_RXDMA;
+ }
+ }
+
+ rcar_i2c_init(priv);
+
+ for (i = 0; i < num; i++)
+ rcar_i2c_request_dma(priv, msgs + i);
+
+ /* init first message */
+ priv->msg = msgs;
+ priv->msgs_left = num;
+ priv->flags = (priv->flags & ID_P_MASK) | ID_FIRST_MSG;
+ rcar_i2c_prepare_msg(priv);
+
+ time_left = wait_event_timeout(priv->wait, priv->flags & ID_DONE,
+ num * adap->timeout);
+
+ /* cleanup DMA if it couldn't complete properly due to an error */
+ if (priv->dma_direction != DMA_NONE)
+ rcar_i2c_cleanup_dma(priv);
+
+ if (!time_left) {
+ rcar_i2c_init(priv);
+ ret = -ETIMEDOUT;
+ } else if (priv->flags & ID_NACK) {
+ ret = -ENXIO;
+ } else if (priv->flags & ID_ARBLOST) {
+ ret = -EAGAIN;
+ } else {
+ ret = num - priv->msgs_left; /* The number of transfer */
+ }
+out:
+ pm_runtime_put(dev);
+
+ if (ret < 0 && ret != -ENXIO)
+ dev_err(dev, "error %d : %x\n", ret, priv->flags);
+
+ return ret;
+}
+
+static int rcar_reg_slave(struct i2c_client *slave)
+{
+ struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
+
+ if (priv->slave)
+ return -EBUSY;
+
+ if (slave->flags & I2C_CLIENT_TEN)
+ return -EAFNOSUPPORT;
+
+ /* Keep device active for slave address detection logic */
+ pm_runtime_get_sync(rcar_i2c_priv_to_dev(priv));
+
+ priv->slave = slave;
+ rcar_i2c_write(priv, ICSAR, slave->addr);
+ rcar_i2c_write(priv, ICSSR, 0);
+ rcar_i2c_write(priv, ICSIER, SAR | SSR);
+ rcar_i2c_write(priv, ICSCR, SIE | SDBS);
+
+ return 0;
+}
+
+static int rcar_unreg_slave(struct i2c_client *slave)
+{
+ struct rcar_i2c_priv *priv = i2c_get_adapdata(slave->adapter);
+
+ WARN_ON(!priv->slave);
+
+ rcar_i2c_write(priv, ICSIER, 0);
+ rcar_i2c_write(priv, ICSCR, 0);
+
+ priv->slave = NULL;
+
+ pm_runtime_put(rcar_i2c_priv_to_dev(priv));
+
+ return 0;
+}
+
+static u32 rcar_i2c_func(struct i2c_adapter *adap)
+{
+ /*
+ * This HW can't do:
+ * I2C_SMBUS_QUICK (setting FSB during START didn't work)
+ * I2C_M_NOSTART (automatically sends address after START)
+ * I2C_M_IGNORE_NAK (automatically sends STOP after NAK)
+ */
+ return I2C_FUNC_I2C | I2C_FUNC_SLAVE |
+ (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
+}
+
+static const struct i2c_algorithm rcar_i2c_algo = {
+ .master_xfer = rcar_i2c_master_xfer,
+ .functionality = rcar_i2c_func,
+ .reg_slave = rcar_reg_slave,
+ .unreg_slave = rcar_unreg_slave,
+};
+
+static const struct i2c_adapter_quirks rcar_i2c_quirks = {
+ .flags = I2C_AQ_NO_ZERO_LEN,
+};
+
+static const struct of_device_id rcar_i2c_dt_ids[] = {
+ { .compatible = "renesas,i2c-r8a7778", .data = (void *)I2C_RCAR_GEN1 },
+ { .compatible = "renesas,i2c-r8a7779", .data = (void *)I2C_RCAR_GEN1 },
+ { .compatible = "renesas,i2c-r8a7790", .data = (void *)I2C_RCAR_GEN2 },
+ { .compatible = "renesas,i2c-r8a7791", .data = (void *)I2C_RCAR_GEN2 },
+ { .compatible = "renesas,i2c-r8a7792", .data = (void *)I2C_RCAR_GEN2 },
+ { .compatible = "renesas,i2c-r8a7793", .data = (void *)I2C_RCAR_GEN2 },
+ { .compatible = "renesas,i2c-r8a7794", .data = (void *)I2C_RCAR_GEN2 },
+ { .compatible = "renesas,i2c-r8a7795", .data = (void *)I2C_RCAR_GEN3 },
+ { .compatible = "renesas,i2c-r8a7796", .data = (void *)I2C_RCAR_GEN3 },
+ { .compatible = "renesas,i2c-rcar", .data = (void *)I2C_RCAR_GEN1 }, /* Deprecated */
+ { .compatible = "renesas,rcar-gen1-i2c", .data = (void *)I2C_RCAR_GEN1 },
+ { .compatible = "renesas,rcar-gen2-i2c", .data = (void *)I2C_RCAR_GEN2 },
+ { .compatible = "renesas,rcar-gen3-i2c", .data = (void *)I2C_RCAR_GEN3 },
+ {},
+};
+MODULE_DEVICE_TABLE(of, rcar_i2c_dt_ids);
+
+static int rcar_i2c_probe(struct platform_device *pdev)
+{
+ struct rcar_i2c_priv *priv;
+ struct i2c_adapter *adap;
+ struct device *dev = &pdev->dev;
+ struct i2c_timings i2c_t;
+ int irq, ret;
+
+ priv = devm_kzalloc(dev, sizeof(struct rcar_i2c_priv), GFP_KERNEL);
+ if (!priv)
+ return -ENOMEM;
+
+ priv->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(priv->clk)) {
+ dev_err(dev, "cannot get clock\n");
+ return PTR_ERR(priv->clk);
+ }
+
+ priv->res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+
+ priv->io = devm_ioremap_resource(dev, priv->res);
+ if (IS_ERR(priv->io))
+ return PTR_ERR(priv->io);
+
+ priv->devtype = (enum rcar_i2c_type)of_device_get_match_data(dev);
+ init_waitqueue_head(&priv->wait);
+
+ adap = &priv->adap;
+ adap->nr = pdev->id;
+ adap->algo = &rcar_i2c_algo;
+ adap->class = I2C_CLASS_DEPRECATED;
+ adap->retries = 3;
+ adap->dev.parent = dev;
+ adap->dev.of_node = dev->of_node;
+ adap->bus_recovery_info = &rcar_i2c_bri;
+ adap->quirks = &rcar_i2c_quirks;
+ i2c_set_adapdata(adap, priv);
+ strlcpy(adap->name, pdev->name, sizeof(adap->name));
+
+ i2c_parse_fw_timings(dev, &i2c_t, false);
+
+ /* Init DMA */
+ sg_init_table(&priv->sg, 1);
+ priv->dma_direction = DMA_NONE;
+ priv->dma_rx = priv->dma_tx = ERR_PTR(-EPROBE_DEFER);
+
+ /* Activate device for clock calculation */
+ pm_runtime_enable(dev);
+ pm_runtime_get_sync(dev);
+ ret = rcar_i2c_clock_calculate(priv, &i2c_t);
+ if (ret < 0)
+ goto out_pm_put;
+
+ if (priv->devtype == I2C_RCAR_GEN3) {
+ priv->rstc = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+ if (!IS_ERR(priv->rstc)) {
+ ret = reset_control_status(priv->rstc);
+ if (ret < 0)
+ priv->rstc = ERR_PTR(-ENOTSUPP);
+ }
+ }
+
+ /* Stay always active when multi-master to keep arbitration working */
+ if (of_property_read_bool(dev->of_node, "multi-master"))
+ priv->flags |= ID_P_PM_BLOCKED;
+ else
+ pm_runtime_put(dev);
+
+
+ irq = platform_get_irq(pdev, 0);
+ ret = devm_request_irq(dev, irq, rcar_i2c_irq, 0, dev_name(dev), priv);
+ if (ret < 0) {
+ dev_err(dev, "cannot get irq %d\n", irq);
+ goto out_pm_disable;
+ }
+
+ platform_set_drvdata(pdev, priv);
+
+ ret = i2c_add_numbered_adapter(adap);
+ if (ret < 0)
+ goto out_pm_disable;
+
+ dev_info(dev, "probed\n");
+
+ return 0;
+
+ out_pm_put:
+ pm_runtime_put(dev);
+ out_pm_disable:
+ pm_runtime_disable(dev);
+ return ret;
+}
+
+static int rcar_i2c_remove(struct platform_device *pdev)
+{
+ struct rcar_i2c_priv *priv = platform_get_drvdata(pdev);
+ struct device *dev = &pdev->dev;
+
+ i2c_del_adapter(&priv->adap);
+ rcar_i2c_release_dma(priv);
+ if (priv->flags & ID_P_PM_BLOCKED)
+ pm_runtime_put(dev);
+ pm_runtime_disable(dev);
+
+ return 0;
+}
+
+static struct platform_driver rcar_i2c_driver = {
+ .driver = {
+ .name = "i2c-rcar",
+ .of_match_table = rcar_i2c_dt_ids,
+ },
+ .probe = rcar_i2c_probe,
+ .remove = rcar_i2c_remove,
+};
+
+module_platform_driver(rcar_i2c_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_DESCRIPTION("Renesas R-Car I2C bus driver");
+MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");