forked from ~ljy/RK356X_SDK_RELEASE
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hc
2023-12-09 b22da3d8526a935aa31e086e63f60ff3246cb61c 
 kernel/drivers/tty/serial/omap-serial.c
....@@ -16,10 +16,6 @@
1616  * this driver as required for the omap-platform.
1717  */
1818 
19
-#if defined(CONFIG_SERIAL_OMAP_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
20
-#define SUPPORT_SYSRQ
21
-#endif
22
-
2319 #include <linux/module.h>
2420 #include <linux/init.h>
2521 #include <linux/console.h>
....@@ -37,11 +33,8 @@
3733 #include <linux/pm_wakeirq.h>
3834 #include <linux/of.h>
3935 #include <linux/of_irq.h>
40
-#include <linux/gpio.h>
41
-#include <linux/of_gpio.h>
36
+#include <linux/gpio/consumer.h>
4237 #include <linux/platform_data/serial-omap.h>
43
-
44
-#include <dt-bindings/gpio/gpio.h>
4538 
4639 #define OMAP_MAX_HSUART_PORTS	10
4740 
....@@ -159,13 +152,15 @@
159152 	u32			errata;
160153 	u32			features;
161154 
162
-	int			rts_gpio;
155
+	struct gpio_desc	*rts_gpiod;
163156 
164157 	struct pm_qos_request	pm_qos_request;
165158 	u32			latency;
166159 	u32			calc_latency;
167160 	struct work_struct	qos_work;
168161 	bool			is_suspending;
162
+
163
+	unsigned int		rs485_tx_filter_count;
169164 };
170165 
171166 #define to_uart_omap_port(p) ((container_of((p), struct uart_omap_port, port)))
....@@ -309,11 +304,12 @@
309304 			serial_out(up, UART_OMAP_SCR, up->scr);
310305 			res = (port->rs485.flags & SER_RS485_RTS_AFTER_SEND) ?
311306 				1 : 0;
312
-			if (gpio_get_value(up->rts_gpio) != res) {
307
+			if (up->rts_gpiod &&
308
+			    gpiod_get_value(up->rts_gpiod) != res) {
313309 				if (port->rs485.delay_rts_after_send > 0)
314310 					mdelay(
315311 					port->rs485.delay_rts_after_send);
316
-				gpio_set_value(up->rts_gpio, res);
312
+				gpiod_set_value(up->rts_gpiod, res);
317313 			}
318314 		} else {
319315 			/* We're asked to stop, but there's still stuff in the
....@@ -332,19 +328,6 @@
332328 
333329 	if (up->ier & UART_IER_THRI) {
334330 		up->ier &= ~UART_IER_THRI;
335
-		serial_out(up, UART_IER, up->ier);
336
-	}
337
-
338
-	if ((port->rs485.flags & SER_RS485_ENABLED) &&
339
-	    !(port->rs485.flags & SER_RS485_RX_DURING_TX)) {
340
-		/*
341
-		 * Empty the RX FIFO, we are not interested in anything
342
-		 * received during the half-duplex transmission.
343
-		 */
344
-		serial_out(up, UART_FCR, up->fcr | UART_FCR_CLEAR_RCVR);
345
-		/* Re-enable RX interrupts */
346
-		up->ier |= UART_IER_RLSI | UART_IER_RDI;
347
-		up->port.read_status_mask |= UART_LSR_DR;
348331 		serial_out(up, UART_IER, up->ier);
349332 	}
350333 
....@@ -373,6 +356,10 @@
373356 		serial_out(up, UART_TX, up->port.x_char);
374357 		up->port.icount.tx++;
375358 		up->port.x_char = 0;
359
+		if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
360
+		    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX))
361
+			up->rs485_tx_filter_count++;
362
+
376363 		return;
377364 	}
378365 	if (uart_circ_empty(xmit) || uart_tx_stopped(&up->port)) {
....@@ -384,6 +371,10 @@
384371 		serial_out(up, UART_TX, xmit->buf[xmit->tail]);
385372 		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
386373 		up->port.icount.tx++;
374
+		if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
375
+		    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX))
376
+			up->rs485_tx_filter_count++;
377
+
387378 		if (uart_circ_empty(xmit))
388379 			break;
389380 	} while (--count > 0);
....@@ -418,8 +409,8 @@
418409 
419410 		/* if rts not already enabled */
420411 		res = (port->rs485.flags & SER_RS485_RTS_ON_SEND) ? 1 : 0;
421
-		if (gpio_get_value(up->rts_gpio) != res) {
422
-			gpio_set_value(up->rts_gpio, res);
412
+		if (up->rts_gpiod && gpiod_get_value(up->rts_gpiod) != res) {
413
+			gpiod_set_value(up->rts_gpiod, res);
423414 			if (port->rs485.delay_rts_before_send > 0)
424415 				mdelay(port->rs485.delay_rts_before_send);
425416 		}
....@@ -427,7 +418,7 @@
427418 
428419 	if ((port->rs485.flags & SER_RS485_ENABLED) &&
429420 	    !(port->rs485.flags & SER_RS485_RX_DURING_TX))
430
-		serial_omap_stop_rx(port);
421
+		up->rs485_tx_filter_count = 0;
431422 
432423 	serial_omap_enable_ier_thri(up);
433424 	pm_runtime_mark_last_busy(up->dev);
....@@ -493,10 +484,18 @@
493484 static void serial_omap_rlsi(struct uart_omap_port *up, unsigned int lsr)
494485 {
495486 	unsigned int flag;
496
-	unsigned char ch = 0;
497487 
498
-	if (likely(lsr & UART_LSR_DR))
499
-		ch = serial_in(up, UART_RX);
488
+	/*
489
+	 * Read one data character out to avoid stalling the receiver according
490
+	 * to the table 23-246 of the omap4 TRM.
491
+	 */
492
+	if (likely(lsr & UART_LSR_DR)) {
493
+		serial_in(up, UART_RX);
494
+		if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
495
+		    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX) &&
496
+		    up->rs485_tx_filter_count)
497
+			up->rs485_tx_filter_count--;
498
+	}
500499 
501500 	up->port.icount.rx++;
502501 	flag = TTY_NORMAL;
....@@ -547,6 +546,13 @@
547546 		return;
548547 
549548 	ch = serial_in(up, UART_RX);
549
+	if ((up->port.rs485.flags & SER_RS485_ENABLED) &&
550
+	    !(up->port.rs485.flags & SER_RS485_RX_DURING_TX) &&
551
+	    up->rs485_tx_filter_count) {
552
+		up->rs485_tx_filter_count--;
553
+		return;
554
+	}
555
+
550556 	flag = TTY_NORMAL;
551557 	up->port.icount.rx++;
552558 
....@@ -591,7 +597,6 @@
591597 			transmit_chars(up, lsr);
592598 			break;
593599 		case UART_IIR_RX_TIMEOUT:
594
-			/* FALLTHROUGH */
595600 		case UART_IIR_RDI:
596601 			serial_omap_rdi(up, lsr);
597602 			break;
....@@ -602,7 +607,6 @@
602607 			/* simply try again */
603608 			break;
604609 		case UART_IIR_XOFF:
605
-			/* FALLTHROUGH */
606610 		default:
607611 			break;
608612 		}
....@@ -832,7 +836,7 @@
832836 	struct uart_omap_port *up = container_of(work, struct uart_omap_port,
833837 						qos_work);
834838 
835
-	pm_qos_update_request(&up->pm_qos_request, up->latency);
839
+	cpu_latency_qos_update_request(&up->pm_qos_request, up->latency);
836840 }
837841 
838842 static void
....@@ -1409,18 +1413,13 @@
14091413 	/* store new config */
14101414 	port->rs485 = *rs485;
14111415 
1412
-	/*
1413
-	 * Just as a precaution, only allow rs485
1414
-	 * to be enabled if the gpio pin is valid
1415
-	 */
1416
-	if (gpio_is_valid(up->rts_gpio)) {
1416
+	if (up->rts_gpiod) {
14171417 		/* enable / disable rts */
14181418 		val = (port->rs485.flags & SER_RS485_ENABLED) ?
14191419 			SER_RS485_RTS_AFTER_SEND : SER_RS485_RTS_ON_SEND;
14201420 		val = (port->rs485.flags & val) ? 1 : 0;
1421
-		gpio_set_value(up->rts_gpio, val);
1422
-	} else
1423
-		port->rs485.flags &= ~SER_RS485_ENABLED;
1421
+		gpiod_set_value(up->rts_gpiod, val);
1422
+	}
14241423 
14251424 	/* Enable interrupts */
14261425 	up->ier = mode;
....@@ -1595,18 +1594,22 @@
15951594 }
15961595 
15971596 static int serial_omap_probe_rs485(struct uart_omap_port *up,
1598
-				   struct device_node *np)
1597
+				   struct device *dev)
15991598 {
16001599 	struct serial_rs485 *rs485conf = &up->port.rs485;
1600
+	struct device_node *np = dev->of_node;
1601
+	enum gpiod_flags gflags;
16011602 	int ret;
16021603 
16031604 	rs485conf->flags = 0;
1604
-	up->rts_gpio = -EINVAL;
1605
+	up->rts_gpiod = NULL;
16051606 
16061607 	if (!np)
16071608 		return 0;
16081609 
1609
-	uart_get_rs485_mode(up->dev, rs485conf);
1610
+	ret = uart_get_rs485_mode(&up->port);
1611
+	if (ret)
1612
+		return ret;
16101613 
16111614 	if (of_property_read_bool(np, "rs485-rts-active-high")) {
16121615 		rs485conf->flags |= SER_RS485_RTS_ON_SEND;
....@@ -1617,19 +1620,20 @@
16171620 	}
16181621 
16191622 	/* check for tx enable gpio */
1620
-	up->rts_gpio = of_get_named_gpio(np, "rts-gpio", 0);
1621
-	if (gpio_is_valid(up->rts_gpio)) {
1622
-		ret = devm_gpio_request(up->dev, up->rts_gpio, "omap-serial");
1623
-		if (ret < 0)
1623
+	gflags = rs485conf->flags & SER_RS485_RTS_AFTER_SEND ?
1624
+		GPIOD_OUT_HIGH : GPIOD_OUT_LOW;
1625
+	up->rts_gpiod = devm_gpiod_get_optional(dev, "rts", gflags);
1626
+	if (IS_ERR(up->rts_gpiod)) {
1627
+		ret = PTR_ERR(up->rts_gpiod);
1628
+	        if (ret == -EPROBE_DEFER)
16241629 			return ret;
1625
-		ret = rs485conf->flags & SER_RS485_RTS_AFTER_SEND ? 1 : 0;
1626
-		ret = gpio_direction_output(up->rts_gpio, ret);
1627
-		if (ret < 0)
1628
-			return ret;
1629
-	} else if (up->rts_gpio == -EPROBE_DEFER) {
1630
-		return -EPROBE_DEFER;
1630
+		/*
1631
+		 * FIXME: the code historically ignored any other error than
1632
+		 * -EPROBE_DEFER and just went on without GPIO.
1633
+		 */
1634
+		up->rts_gpiod = NULL;
16311635 	} else {
1632
-		up->rts_gpio = -EINVAL;
1636
+		gpiod_set_consumer_name(up->rts_gpiod, "omap-serial");
16331637 	}
16341638 
16351639 	return 0;
....@@ -1676,6 +1680,7 @@
16761680 	up->port.regshift = 2;
16771681 	up->port.fifosize = 64;
16781682 	up->port.ops = &serial_omap_pops;
1683
+	up->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_OMAP_CONSOLE);
16791684 
16801685 	if (pdev->dev.of_node)
16811686 		ret = of_alias_get_id(pdev->dev.of_node, "serial");
....@@ -1701,7 +1706,7 @@
17011706 		dev_info(up->port.dev, "no wakeirq for uart%d\n",
17021707 			 up->port.line);
17031708 
1704
-	ret = serial_omap_probe_rs485(up, pdev->dev.of_node);
1709
+	ret = serial_omap_probe_rs485(up, &pdev->dev);
17051710 	if (ret < 0)
17061711 		goto err_rs485;
17071712 
....@@ -1718,10 +1723,9 @@
17181723 			 DEFAULT_CLK_SPEED);
17191724 	}
17201725 
1721
-	up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1722
-	up->calc_latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1723
-	pm_qos_add_request(&up->pm_qos_request,
1724
-		PM_QOS_CPU_DMA_LATENCY, up->latency);
1726
+	up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
1727
+	up->calc_latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
1728
+	cpu_latency_qos_add_request(&up->pm_qos_request, up->latency);
17251729 	INIT_WORK(&up->qos_work, serial_omap_uart_qos_work);
17261730 
17271731 	platform_set_drvdata(pdev, up);
....@@ -1755,7 +1759,7 @@
17551759 	pm_runtime_dont_use_autosuspend(&pdev->dev);
17561760 	pm_runtime_put_sync(&pdev->dev);
17571761 	pm_runtime_disable(&pdev->dev);
1758
-	pm_qos_remove_request(&up->pm_qos_request);
1762
+	cpu_latency_qos_remove_request(&up->pm_qos_request);
17591763 	device_init_wakeup(up->dev, false);
17601764 err_rs485:
17611765 err_port_line:
....@@ -1773,7 +1777,7 @@
17731777 	pm_runtime_dont_use_autosuspend(up->dev);
17741778 	pm_runtime_put_sync(up->dev);
17751779 	pm_runtime_disable(up->dev);
1776
-	pm_qos_remove_request(&up->pm_qos_request);
1780
+	cpu_latency_qos_remove_request(&up->pm_qos_request);
17771781 	device_init_wakeup(&dev->dev, false);
17781782 
17791783 	return 0;
....@@ -1865,7 +1869,7 @@
18651869 
18661870 	serial_omap_enable_wakeup(up, true);
18671871 
1868
-	up->latency = PM_QOS_CPU_DMA_LAT_DEFAULT_VALUE;
1872
+	up->latency = PM_QOS_CPU_LATENCY_DEFAULT_VALUE;
18691873 	schedule_work(&up->qos_work);
18701874 
18711875 	return 0;