1 files changed, 119 insertions, 104 deletions

diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index 51329625c48a..9799356b65f7 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -4,7 +4,10 @@
  *
  *    Copyright (C) 2006 Arnd Bergmann <arnd@arndb.de>, IBM Corp.
  */
+
+#include <linux/bits.h>
 #include <linux/console.h>
+#include <linux/math.h>
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/serial_core.h>
@@ -15,16 +18,69 @@
 #include <linux/pm_runtime.h>
 #include <linux/clk.h>
 #include <linux/reset.h>
+#include <linux/notifier.h>
 
 #include "8250.h"
 
 struct of_serial_info {
 	struct clk *clk;
+	struct clk *bus_clk;
 	struct reset_control *rst;
 	int type;
 	int line;
+	struct notifier_block clk_notifier;
 };
 
+/* Nuvoton NPCM timeout register */
+#define UART_NPCM_TOR          7
+#define UART_NPCM_TOIE         BIT(7)  /* Timeout Interrupt Enable */
+
+static int npcm_startup(struct uart_port *port)
+{
+	/*
+	 * Nuvoton calls the scratch register 'UART_TOR' (timeout
+	 * register). Enable it, and set TIOC (timeout interrupt
+	 * comparator) to be 0x20 for correct operation.
+	 */
+	serial_port_out(port, UART_NPCM_TOR, UART_NPCM_TOIE | 0x20);
+
+	return serial8250_do_startup(port);
+}
+
+/* Nuvoton NPCM UARTs have a custom divisor calculation */
+static unsigned int npcm_get_divisor(struct uart_port *port, unsigned int baud,
+				     unsigned int *frac)
+{
+	return DIV_ROUND_CLOSEST(port->uartclk, 16 * baud + 2) - 2;
+}
+
+static int npcm_setup(struct uart_port *port)
+{
+	port->get_divisor = npcm_get_divisor;
+	port->startup = npcm_startup;
+	return 0;
+}
+
+static inline struct of_serial_info *clk_nb_to_info(struct notifier_block *nb)
+{
+	return container_of(nb, struct of_serial_info, clk_notifier);
+}
+
+static int of_platform_serial_clk_notifier_cb(struct notifier_block *nb, unsigned long event,
+					      void *data)
+{
+	struct of_serial_info *info = clk_nb_to_info(nb);
+	struct uart_8250_port *port8250 = serial8250_get_port(info->line);
+	struct clk_notifier_data *ndata = data;
+
+	if (event == POST_RATE_CHANGE) {
+		serial8250_update_uartclk(&port8250->port, ndata->new_rate);
+		return NOTIFY_OK;
+	}
+
+	return NOTIFY_DONE;
+}
+
 /*
  * Fill a struct uart_port for a given device node
  */
@@ -33,137 +89,78 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 			struct of_serial_info *info)
 {
 	struct resource resource;
-	struct device_node *np = ofdev->dev.of_node;
+	struct device *dev = &ofdev->dev;
+	struct device_node *np = dev->of_node;
 	struct uart_port *port = &up->port;
-	u32 clk, spd, prop;
-	int ret, irq;
+	u32 spd;
+	int ret;
 
-	memset(port, 0, sizeof *port);
+	memset(port, 0, sizeof(*port));
 
 	pm_runtime_enable(&ofdev->dev);
 	pm_runtime_get_sync(&ofdev->dev);
 
-	if (of_property_read_u32(np, "clock-frequency", &clk)) {
-
-		/* Get clk rate through clk driver if present */
-		info->clk = devm_clk_get(&ofdev->dev, NULL);
-		if (IS_ERR(info->clk)) {
-			ret = PTR_ERR(info->clk);
-			if (ret != -EPROBE_DEFER)
-				dev_warn(&ofdev->dev,
-					 "failed to get clock: %d\n", ret);
-			goto err_pmruntime;
-		}
-
-		ret = clk_prepare_enable(info->clk);
-		if (ret < 0)
-			goto err_pmruntime;
-
-		clk = clk_get_rate(info->clk);
-	}
-	/* If current-speed was set, then try not to change it. */
-	if (of_property_read_u32(np, "current-speed", &spd) == 0)
-		port->custom_divisor = clk / (16 * spd);
-
 	ret = of_address_to_resource(np, 0, &resource);
 	if (ret) {
-		dev_warn(&ofdev->dev, "invalid address\n");
-		goto err_unprepare;
+		dev_err_probe(dev, ret, "invalid address\n");
+		goto err_pmruntime;
 	}
 
-	port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT |
-				  UPF_FIXED_TYPE;
+	port->dev = &ofdev->dev;
+	port->flags = UPF_BOOT_AUTOCONF | UPF_FIXED_PORT | UPF_FIXED_TYPE;
 	spin_lock_init(&port->lock);
 
 	if (resource_type(&resource) == IORESOURCE_IO) {
-		port->iotype = UPIO_PORT;
 		port->iobase = resource.start;
 	} else {
 		port->mapbase = resource.start;
 		port->mapsize = resource_size(&resource);
-
-		/* Check for shifted address mapping */
-		if (of_property_read_u32(np, "reg-offset", &prop) == 0) {
-			if (prop >= port->mapsize) {
-				dev_warn(&ofdev->dev, "reg-offset %u exceeds region size %pa\n",
-					 prop, &port->mapsize);
-				ret = -EINVAL;
-				goto err_unprepare;
-			}
-
-			port->mapbase += prop;
-			port->mapsize -= prop;
-		}
-
-		port->iotype = UPIO_MEM;
-		if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
-			switch (prop) {
-			case 1:
-				port->iotype = UPIO_MEM;
-				break;
-			case 2:
-				port->iotype = UPIO_MEM16;
-				break;
-			case 4:
-				port->iotype = of_device_is_big_endian(np) ?
-					       UPIO_MEM32BE : UPIO_MEM32;
-				break;
-			default:
-				dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
-					 prop);
-				ret = -EINVAL;
-				goto err_unprepare;
-			}
-		}
 		port->flags |= UPF_IOREMAP;
 	}
 
-	/* Compatibility with the deprecated pxa driver and 8250_pxa drivers. */
-	if (of_device_is_compatible(np, "mrvl,mmp-uart"))
-		port->regshift = 2;
-
-	/* Check for registers offset within the devices address range */
-	if (of_property_read_u32(np, "reg-shift", &prop) == 0)
-		port->regshift = prop;
+	ret = uart_read_and_validate_port_properties(port);
+	if (ret)
+		goto err_pmruntime;
 
-	/* Check for fifo size */
-	if (of_property_read_u32(np, "fifo-size", &prop) == 0)
-		port->fifosize = prop;
+	/* Get clk rate through clk driver if present */
+	if (!port->uartclk) {
+		struct clk *bus_clk;
 
-	/* Check for a fixed line number */
-	ret = of_alias_get_id(np, "serial");
-	if (ret >= 0)
-		port->line = ret;
+		bus_clk = devm_clk_get_optional_enabled(dev, "bus");
+		if (IS_ERR(bus_clk)) {
+			ret = dev_err_probe(dev, PTR_ERR(bus_clk), "failed to get bus clock\n");
+			goto err_pmruntime;
+		}
 
-	irq = of_irq_get(np, 0);
-	if (irq < 0) {
-		if (irq == -EPROBE_DEFER) {
-			ret = -EPROBE_DEFER;
-			goto err_unprepare;
+		/* If the bus clock is required, core clock must be named */
+		info->clk = devm_clk_get_enabled(dev, bus_clk ? "core" : NULL);
+		if (IS_ERR(info->clk)) {
+			ret = dev_err_probe(dev, PTR_ERR(info->clk), "failed to get clock\n");
+			goto err_pmruntime;
 		}
-		/* IRQ support not mandatory */
-		irq = 0;
+
+		info->bus_clk = bus_clk;
+		port->uartclk = clk_get_rate(info->clk);
 	}
+	/* If current-speed was set, then try not to change it. */
+	if (of_property_read_u32(np, "current-speed", &spd) == 0)
+		port->custom_divisor = port->uartclk / (16 * spd);
 
-	port->irq = irq;
+	/* Compatibility with the deprecated pxa driver and 8250_pxa drivers. */
+	if (of_device_is_compatible(np, "mrvl,mmp-uart"))
+		port->regshift = 2;
 
 	info->rst = devm_reset_control_get_optional_shared(&ofdev->dev, NULL);
 	if (IS_ERR(info->rst)) {
 		ret = PTR_ERR(info->rst);
-		goto err_unprepare;
+		goto err_pmruntime;
 	}
 
 	ret = reset_control_deassert(info->rst);
 	if (ret)
-		goto err_unprepare;
+		goto err_pmruntime;
 
 	port->type = type;
-	port->uartclk = clk;
-
-	if (of_property_read_bool(np, "no-loopback-test"))
-		port->flags |= UPF_SKIP_TEST;
-
-	port->dev = &ofdev->dev;
 	port->rs485_config = serial8250_em485_config;
 	port->rs485_supported = serial8250_em485_supported;
 	up->rs485_start_tx = serial8250_em485_start_tx;
@@ -172,10 +169,17 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 	switch (type) {
 	case PORT_RT2880:
 		ret = rt288x_setup(port);
-		if (ret)
-			goto err_unprepare;
+		break;
+	case PORT_NPCM:
+		ret = npcm_setup(port);
+		break;
+	default:
+		/* Nothing to do */
+		ret = 0;
 		break;
 	}
+	if (ret)
+		goto err_pmruntime;
 
 	if (IS_REACHABLE(CONFIG_SERIAL_8250_FSL) &&
 	    (of_device_is_compatible(np, "fsl,ns16550") ||
@@ -185,8 +189,6 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 	}
 
 	return 0;
-err_unprepare:
-	clk_disable_unprepare(info->clk);
 err_pmruntime:
 	pm_runtime_put_sync(&ofdev->dev);
 	pm_runtime_disable(&ofdev->dev);
@@ -248,12 +250,22 @@ static int of_platform_serial_probe(struct platform_device *ofdev)
 	info->type = port_type;
 	info->line = ret;
 	platform_set_drvdata(ofdev, info);
+
+	if (info->clk) {
+		info->clk_notifier.notifier_call = of_platform_serial_clk_notifier_cb;
+		ret = clk_notifier_register(info->clk, &info->clk_notifier);
+		if (ret) {
+			dev_err_probe(port8250.port.dev, ret, "Failed to set the clock notifier\n");
+			goto err_unregister;
+		}
+	}
+
 	return 0;
+err_unregister:
+	serial8250_unregister_port(info->line);
 err_dispose:
-	irq_dispose_mapping(port8250.port.irq);
 	pm_runtime_put_sync(&ofdev->dev);
 	pm_runtime_disable(&ofdev->dev);
-	clk_disable_unprepare(info->clk);
 err_free:
 	kfree(info);
 	return ret;
@@ -262,18 +274,19 @@ err_free:
 /*
  * Release a line
  */
-static int of_platform_serial_remove(struct platform_device *ofdev)
+static void of_platform_serial_remove(struct platform_device *ofdev)
 {
 	struct of_serial_info *info = platform_get_drvdata(ofdev);
 
+	if (info->clk)
+		clk_notifier_unregister(info->clk, &info->clk_notifier);
+
 	serial8250_unregister_port(info->line);
 
 	reset_control_assert(info->rst);
 	pm_runtime_put_sync(&ofdev->dev);
 	pm_runtime_disable(&ofdev->dev);
-	clk_disable_unprepare(info->clk);
 	kfree(info);
-	return 0;
 }
 
 #ifdef CONFIG_PM_SLEEP
@@ -288,6 +301,7 @@ static int of_serial_suspend(struct device *dev)
 	if (!uart_console(port) || console_suspend_enabled) {
 		pm_runtime_put_sync(dev);
 		clk_disable_unprepare(info->clk);
+		clk_disable_unprepare(info->bus_clk);
 	}
 	return 0;
 }
@@ -300,6 +314,7 @@ static int of_serial_resume(struct device *dev)
 
 	if (!uart_console(port) || console_suspend_enabled) {
 		pm_runtime_get_sync(dev);
+		clk_prepare_enable(info->bus_clk);
 		clk_prepare_enable(info->clk);
 	}