Update Linux to v5.10.109

Sourced from [1]

[1] https://cdn.kernel.org/pub/linux/kernel/v5.x/linux-5.10.109.tar.xz

Change-Id: I19bca9fc6762d4e63bcf3e4cba88bbe560d9c76c
Signed-off-by: Olivier Deprez <olivier.deprez@arm.com>
diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c
index 6420ae5..84e8158 100644
--- a/drivers/tty/serial/omap-serial.c
+++ b/drivers/tty/serial/omap-serial.c
@@ -16,10 +16,6 @@
  * this driver as required for the omap-platform.
  */
 
-#if defined(CONFIG_SERIAL_OMAP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
-#define SUPPORT_SYSRQ
-#endif
-
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/console.h>
@@ -37,12 +33,9 @@
 #include <linux/pm_wakeirq.h>
 #include <linux/of.h>
 #include <linux/of_irq.h>
-#include <linux/gpio.h>
-#include <linux/of_gpio.h>
+#include <linux/gpio/consumer.h>
 #include <linux/platform_data/serial-omap.h>
 
-#include <dt-bindings/gpio/gpio.h>
-
 #define OMAP_MAX_HSUART_PORTS	10
 
 #define UART_BUILD_REVISION(x, y)	(((x) << 8) | (y))
@@ -159,13 +152,15 @@
 	u32			errata;
 	u32			features;
 
-	int			rts_gpio;
+	struct gpio_desc	*rts_gpiod;
 
 	struct pm_qos_request	pm_qos_request;
 	u32			latency;
 	u32			calc_latency;
 	struct work_struct	qos_work;
 	bool			is_suspending;
+
+	unsigned int		rs485_tx_filter_count;
 };
 
 #define to_uart_omap_port(p) ((container_of((p), struct uart_omap_port, port)))
@@ -309,11 +304,12 @@
 			serial_out(up, UART_OMAP_SCR, up->scr);
 			res = (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) ?
 				1 : 0;
-			if (gpio_get_value(up->rts_gpio) != res) {
+			if (up->rts_gpiod &&
+			    gpiod_get_value(up->rts_gpiod) != res) {
 				if (port->rs485.delay_rts_after_send > 0)
 					mdelay(
 					port->rs485.delay_rts_after_send);
-				gpio_set_value(up->rts_gpio, res);
+				gpiod_set_value(up->rts_gpiod, res);
 			}
 		} else {
 			/* We're asked to stop, but there's still stuff in the
@@ -335,19 +331,6 @@
 		serial_out(up, UART_IER, up->ier);
 	}
 
-	if ((port->rs485.flags & SER_RS485_ENABLED) &&
-	    !(port->rs485.flags & SER_RS485_RX_DURING_TX)) {
-		/*
-		 * Empty the RX FIFO, we are not interested in anything
-		 * received during the half-duplex transmission.
-		 */
-		serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_RCVR);
-		/* Re-enable RX interrupts */
-		up->ier |= UART_IER_RLSI | UART_IER_RDI;
-		up->port.read_status_mask |= UART_LSR_DR;
-		serial_out(up, UART_IER, up->ier);
-	}
-
 	pm_runtime_mark_last_busy(up->dev);
 	pm_runtime_put_autosuspend(up->dev);
 }
@@ -373,6 +356,10 @@
 		serial_out(up, UART_TX, up->port.x_char);
 		up->port.icount.tx++;
 		up->port.x_char = 0;
+		if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
+		    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX))
+			up->rs485_tx_filter_count++;
+
 		return;
 	}
 	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
@@ -384,6 +371,10 @@
 		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
 		up->port.icount.tx++;
+		if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
+		    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX))
+			up->rs485_tx_filter_count++;
+
 		if (uart_circ_empty(xmit))
 			break;
 	} while (--count > 0);
@@ -418,8 +409,8 @@
 
 		/* if rts not already enabled */
 		res = (port->rs485.flags & SER_RS485_RTS_ON_SEND) ? 1 : 0;
-		if (gpio_get_value(up->rts_gpio) != res) {
-			gpio_set_value(up->rts_gpio, res);
+		if (up->rts_gpiod && gpiod_get_value(up->rts_gpiod) != res) {
+			gpiod_set_value(up->rts_gpiod, res);
 			if (port->rs485.delay_rts_before_send > 0)
 				mdelay(port->rs485.delay_rts_before_send);
 		}
@@ -427,7 +418,7 @@
 
 	if ((port->rs485.flags & SER_RS485_ENABLED) &&
 	    !(port->rs485.flags & SER_RS485_RX_DURING_TX))
-		serial_omap_stop_rx(port);
+		up->rs485_tx_filter_count = 0;
 
 	serial_omap_enable_ier_thri(up);
 	pm_runtime_mark_last_busy(up->dev);
@@ -493,10 +484,18 @@
 static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr)
 {
 	unsigned int flag;
-	unsigned char ch = 0;
 
-	if (likely(lsr & UART_LSR_DR))
-		ch = serial_in(up, UART_RX);
+	/*
+	 * Read one data character out to avoid stalling the receiver according
+	 * to the table 23-246 of the omap4 TRM.
+	 */
+	if (likely(lsr & UART_LSR_DR)) {
+		serial_in(up, UART_RX);
+		if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
+		    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX) &&
+		    up->rs485_tx_filter_count)
+			up->rs485_tx_filter_count--;
+	}
 
 	up->port.icount.rx++;
 	flag = TTY_NORMAL;
@@ -547,6 +546,13 @@
 		return;
 
 	ch = serial_in(up, UART_RX);
+	if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
+	    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX) &&
+	    up->rs485_tx_filter_count) {
+		up->rs485_tx_filter_count--;
+		return;
+	}
+
 	flag = TTY_NORMAL;
 	up->port.icount.rx++;
 
@@ -591,7 +597,6 @@
 			transmit_chars(up, lsr);
 			break;
 		case UART_IIR_RX_TIMEOUT:
-			/* FALLTHROUGH */
 		case UART_IIR_RDI:
 			serial_omap_rdi(up, lsr);
 			break;
@@ -602,7 +607,6 @@
 			/* simply try again */
 			break;
 		case UART_IIR_XOFF:
-			/* FALLTHROUGH */
 		default:
 			break;
 		}
@@ -832,7 +836,7 @@
 	struct uart_omap_port *up = container_of(work, struct uart_omap_port,
 						qos_work);
 
-	pm_qos_update_request(&up->pm_qos_request, up->latency);
+	cpu_latency_qos_update_request(&up->pm_qos_request, up->latency);
 }
 
 static void
@@ -1413,18 +1417,13 @@
 	/* store new config */
 	port->rs485 = *rs485;
 
-	/*
-	 * Just as a precaution, only allow rs485
-	 * to be enabled if the gpio pin is valid
-	 */
-	if (gpio_is_valid(up->rts_gpio)) {
+	if (up->rts_gpiod) {
 		/* enable / disable rts */
 		val = (port->rs485.flags & SER_RS485_ENABLED) ?
 			SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND;
 		val = (port->rs485.flags & val) ? 1 : 0;
-		gpio_set_value(up->rts_gpio, val);
-	} else
-		port->rs485.flags &= ~SER_RS485_ENABLED;
+		gpiod_set_value(up->rts_gpiod, val);
+	}
 
 	/* Enable interrupts */
 	up->ier = mode;
@@ -1599,18 +1598,22 @@
 }
 
 static int serial_omap_probe_rs485(struct uart_omap_port *up,
-				   struct device_node *np)
+				   struct device *dev)
 {
 	struct serial_rs485 *rs485conf = &up->port.rs485;
+	struct device_node *np = dev->of_node;
+	enum gpiod_flags gflags;
 	int ret;
 
 	rs485conf->flags = 0;
-	up->rts_gpio = -EINVAL;
+	up->rts_gpiod = NULL;
 
 	if (!np)
 		return 0;
 
-	uart_get_rs485_mode(up->dev, rs485conf);
+	ret = uart_get_rs485_mode(&up->port);
+	if (ret)
+		return ret;
 
 	if (of_property_read_bool(np, "rs485-rts-active-high")) {
 		rs485conf->flags |= SER_RS485_RTS_ON_SEND;
@@ -1621,19 +1624,20 @@
 	}
 
 	/* check for tx enable gpio */
-	up->rts_gpio = of_get_named_gpio(np, "rts-gpio", 0);
-	if (gpio_is_valid(up->rts_gpio)) {
-		ret = devm_gpio_request(up->dev, up->rts_gpio, "omap-serial");
-		if (ret < 0)
+	gflags = rs485conf->flags & SER_RS485_RTS_AFTER_SEND ?
+		GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
+	up->rts_gpiod = devm_gpiod_get_optional(dev, "rts", gflags);
+	if (IS_ERR(up->rts_gpiod)) {
+		ret = PTR_ERR(up->rts_gpiod);
+	        if (ret == -EPROBE_DEFER)
 			return ret;
-		ret = rs485conf->flags & SER_RS485_RTS_AFTER_SEND ? 1 : 0;
-		ret = gpio_direction_output(up->rts_gpio, ret);
-		if (ret < 0)
-			return ret;
-	} else if (up->rts_gpio == -EPROBE_DEFER) {
-		return -EPROBE_DEFER;
+		/*
+		 * FIXME: the code historically ignored any other error than
+		 * -EPROBE_DEFER and just went on without GPIO.
+		 */
+		up->rts_gpiod = NULL;
 	} else {
-		up->rts_gpio = -EINVAL;
+		gpiod_set_consumer_name(up->rts_gpiod, "omap-serial");
 	}
 
 	return 0;
@@ -1680,6 +1684,7 @@
 	up->port.regshift = 2;
 	up->port.fifosize = 64;
 	up->port.ops = &serial_omap_pops;
+	up->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_OMAP_CONSOLE);
 
 	if (pdev->dev.of_node)
 		ret = of_alias_get_id(pdev->dev.of_node, "serial");
@@ -1705,7 +1710,7 @@
 		dev_info(up->port.dev, "no wakeirq for uart%d\n",
 			 up->port.line);
 
-	ret = serial_omap_probe_rs485(up, pdev->dev.of_node);
+	ret = serial_omap_probe_rs485(up, &pdev->dev);
 	if (ret < 0)
 		goto err_rs485;
 
@@ -1722,10 +1727,9 @@
 			 DEFAULT_CLK_SPEED);
 	}
 
-	up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
-	up->calc_latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
-	pm_qos_add_request(&up->pm_qos_request,
-		PM_QOS_CPU_DMA_LATENCY, up->latency);
+	up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
+	up->calc_latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
+	cpu_latency_qos_add_request(&up->pm_qos_request, up->latency);
 	INIT_WORK(&up->qos_work, serial_omap_uart_qos_work);
 
 	platform_set_drvdata(pdev, up);
@@ -1759,7 +1763,7 @@
 	pm_runtime_dont_use_autosuspend(&pdev->dev);
 	pm_runtime_put_sync(&pdev->dev);
 	pm_runtime_disable(&pdev->dev);
-	pm_qos_remove_request(&up->pm_qos_request);
+	cpu_latency_qos_remove_request(&up->pm_qos_request);
 	device_init_wakeup(up->dev, false);
 err_rs485:
 err_port_line:
@@ -1777,7 +1781,7 @@
 	pm_runtime_dont_use_autosuspend(up->dev);
 	pm_runtime_put_sync(up->dev);
 	pm_runtime_disable(up->dev);
-	pm_qos_remove_request(&up->pm_qos_request);
+	cpu_latency_qos_remove_request(&up->pm_qos_request);
 	device_init_wakeup(&dev->dev, false);
 
 	return 0;
@@ -1869,7 +1873,7 @@
 
 	serial_omap_enable_wakeup(up, true);
 
-	up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
+	up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
 	schedule_work(&up->qos_work);
 
 	return 0;