[RFC] Allow disabling wakeup for serial ports, including during off mode.

[Russ Dill <russ.dill@gmail.com>]

This patch causes the OMAP uarts to honor the sysfs power/wakeup file for
IOPADs. Before the OMAP was always woken up from off mode on a rs232 signal
change.

This patch also creates a different platform device for each serial
port so that the wakeup properties can be control per port.

The patch is not in a complete state, but for my testing it was necessary
to disable rs232 wakeup as allowing the signals to float in off mode by
powering off the level converters was causing a wakeup event.
---
 arch/arm/mach-omap2/serial.c |  165 ++++++++++++++++++++++++++++++++----------
 1 files changed, 126 insertions(+), 39 deletions(-)

diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index 0762165..95b047a 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -49,6 +49,7 @@ struct omap_uart_state {
 
 	struct plat_serial8250_port *p;
 	struct list_head node;
+	struct platform_device pdev;
 
 #if defined(CONFIG_ARCH_OMAP3) && defined(CONFIG_PM)
 	int context_valid;
@@ -63,10 +64,9 @@ struct omap_uart_state {
 #endif
 };
 
-static struct omap_uart_state omap_uart[OMAP_MAX_NR_PORTS];
 static LIST_HEAD(uart_list);
 
-static struct plat_serial8250_port serial_platform_data[] = {
+static struct plat_serial8250_port serial_platform_data0[] = {
 	{
 		.membase	= IO_ADDRESS(OMAP_UART1_BASE),
 		.mapbase	= OMAP_UART1_BASE,
@@ -76,6 +76,12 @@ static struct plat_serial8250_port serial_platform_data[] = {
 		.regshift	= 2,
 		.uartclk	= OMAP24XX_BASE_BAUD * 16,
 	}, {
+		.flags		= 0
+	}
+};
+
+static struct plat_serial8250_port serial_platform_data1[] = {
+	{
 		.membase	= IO_ADDRESS(OMAP_UART2_BASE),
 		.mapbase	= OMAP_UART2_BASE,
 		.irq		= 73,
@@ -84,6 +90,12 @@ static struct plat_serial8250_port serial_platform_data[] = {
 		.regshift	= 2,
 		.uartclk	= OMAP24XX_BASE_BAUD * 16,
 	}, {
+		.flags		= 0
+	}
+};
+
+static struct plat_serial8250_port serial_platform_data2[] = {
+	{
 		.membase	= IO_ADDRESS(OMAP_UART3_BASE),
 		.mapbase	= OMAP_UART3_BASE,
 		.irq		= 74,
@@ -197,6 +209,40 @@ static inline void omap_uart_save_context(struct omap_uart_state *uart) {}
 static inline void omap_uart_restore_context(struct omap_uart_state *uart) {}
 #endif /* CONFIG_ARCH_OMAP3 */
 
+static void omap_uart_enable_wakeup(struct omap_uart_state *uart)
+{
+	/* Set wake-enable bit */
+	if (uart->wk_en && uart->wk_mask) {
+		u32 v = __raw_readl(uart->wk_en);
+		v |= uart->wk_mask;
+		__raw_writel(v, uart->wk_en);
+	}
+
+	/* Ensure IOPAD wake-enables are set */
+	if (cpu_is_omap34xx() && uart->padconf) {
+		u16 v = omap_ctrl_readw(uart->padconf);
+		v |= OMAP3_PADCONF_WAKEUPENABLE0;
+		omap_ctrl_writew(v, uart->padconf);
+	}
+}
+
+static void omap_uart_disable_wakeup(struct omap_uart_state *uart)
+{
+	/* Clear wake-enable bit */
+	if (uart->wk_en && uart->wk_mask) {
+		u32 v = __raw_readl(uart->wk_en);
+		v &= ~uart->wk_mask;
+		__raw_writel(v, uart->wk_en);
+	}
+
+	/* Ensure IOPAD wake-enables are cleared */
+	if (cpu_is_omap34xx() && uart->padconf) {
+		u16 v = omap_ctrl_readw(uart->padconf);
+		v &= ~OMAP3_PADCONF_WAKEUPENABLE0;
+		omap_ctrl_writew(v, uart->padconf);
+	}
+}
+
 static void omap_uart_smart_idle_enable(struct omap_uart_state *uart,
 					  int enable)
 {
@@ -220,6 +266,11 @@ static inline void omap_uart_restore(struct omap_uart_state *uart)
 
 static inline void omap_uart_disable_clocks(struct omap_uart_state *uart)
 {
+	if (device_may_wakeup(&uart->pdev.dev))
+		omap_uart_enable_wakeup(uart);
+	else
+		omap_uart_disable_wakeup(uart);
+
 	if (!uart->clocked)
 		return;
 
@@ -290,6 +341,7 @@ void omap_uart_resume_idle(int num)
 			if (__raw_readl(uart->wk_st) & uart->wk_mask)
 				omap_uart_block_sleep(uart);
 
+			omap_uart_enable_wakeup(uart);
 			return;
 		}
 	}
@@ -300,6 +352,7 @@ void omap_uart_prepare_suspend(void)
 	struct omap_uart_state *uart;
 
 	list_for_each_entry(uart, &uart_list, node) {
+		omap_uart_enable_wakeup(uart);
 		omap_uart_allow_sleep(uart);
 	}
 }
@@ -343,16 +396,13 @@ static irqreturn_t omap_uart_interrupt(int irq, void *dev_id)
 	return IRQ_NONE;
 }
 
-static u32 sleep_timeout = DEFAULT_TIMEOUT;
-
 static void omap_uart_idle_init(struct omap_uart_state *uart)
 {
-	u32 v;
 	struct plat_serial8250_port *p = uart->p;
 	int ret;
 
 	uart->can_sleep = 0;
-	uart->timeout = sleep_timeout;
+	uart->timeout = DEFAULT_TIMEOUT;
 	setup_timer(&uart->timer, omap_uart_idle_timer,
 		    (unsigned long) uart);
 	mod_timer(&uart->timer, jiffies + uart->timeout);
@@ -410,22 +460,6 @@ static void omap_uart_idle_init(struct omap_uart_state *uart)
 		uart->padconf = 0;
 	}
 
-	/* Set wake-enable bit */
-	if (uart->wk_en && uart->wk_mask) {
-		v = __raw_readl(uart->wk_en);
-		v |= uart->wk_mask;
-		__raw_writel(v, uart->wk_en);
-	}
-
-	/* Ensure IOPAD wake-enables are set */
-	if (cpu_is_omap34xx() && uart->padconf) {
-		u16 v;
-
-		v = omap_ctrl_readw(uart->padconf);
-		v |= OMAP3_PADCONF_WAKEUPENABLE0;
-		omap_ctrl_writew(v, uart->padconf);
-	}
-
 	p->flags |= UPF_SHARE_IRQ;
 	ret = request_irq(p->irq, omap_uart_interrupt, IRQF_SHARED,
 			  "serial idle", (void *)uart);
@@ -450,23 +484,30 @@ static ssize_t sleep_timeout_show(struct kobject *kobj,
 				  struct kobj_attribute *attr,
 				  char *buf)
 {
-	return sprintf(buf, "%u\n", sleep_timeout / HZ);
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct platform_device *pdev = container_of(dev,
+					struct platform_device, dev);
+	struct omap_uart_state *uart = container_of(pdev,
+					struct omap_uart_state, pdev);
+	return sprintf(buf, "%u\n", uart->timeout / HZ);
 }
 
 static ssize_t sleep_timeout_store(struct kobject *kobj,
 				   struct kobj_attribute *attr,
 				   const char *buf, size_t n)
 {
-	struct omap_uart_state *uart;
+	struct device *dev = container_of(kobj, struct device, kobj);
+	struct platform_device *pdev = container_of(dev,
+					struct platform_device, dev);
+	struct omap_uart_state *uart = container_of(pdev,
+					struct omap_uart_state, pdev);
 	unsigned int value;
 
 	if (sscanf(buf, "%u", &value) != 1) {
 		printk(KERN_ERR "sleep_timeout_store: Invalid value\n");
 		return -EINVAL;
 	}
-	sleep_timeout = value * HZ;
-	list_for_each_entry(uart, &uart_list, node)
-		uart->timeout = sleep_timeout;
+	uart->timeout = value * HZ;
 	return n;
 }
 
@@ -477,6 +518,34 @@ static struct kobj_attribute sleep_timeout_attr =
 static inline void omap_uart_idle_init(struct omap_uart_state *uart) {}
 #endif /* CONFIG_PM */
 
+static struct omap_uart_state omap_uart[OMAP_MAX_NR_PORTS] = {
+	{
+		.pdev = {
+			.name			= "serial8250",
+			.id			= PLAT8250_DEV_PLATFORM,
+			.dev			= {
+				.platform_data	= serial_platform_data0,
+			},
+		},
+	}, {
+		.pdev = {
+			.name			= "serial8250",
+			.id			= PLAT8250_DEV_PLATFORM1,
+			.dev			= {
+				.platform_data	= serial_platform_data1,
+			},
+		},
+	}, {
+		.pdev = {
+			.name			= "serial8250",
+			.id			= PLAT8250_DEV_PLATFORM2,
+			.dev			= {
+				.platform_data	= serial_platform_data2,
+			},
+		},
+	},
+};
+
 void __init omap_serial_init(void)
 {
 	int i;
@@ -495,8 +564,8 @@ void __init omap_serial_init(void)
 		return;
 
 	for (i = 0; i < OMAP_MAX_NR_PORTS; i++) {
-		struct plat_serial8250_port *p = serial_platform_data + i;
 		struct omap_uart_state *uart = &omap_uart[i];
+		struct plat_serial8250_port *p = uart->pdev.dev.platform_data;
 
 		if (!(info->enabled_uarts & (1 << i))) {
 			p->membase = NULL;
@@ -532,25 +601,43 @@ void __init omap_serial_init(void)
 	}
 }
 
-static struct platform_device serial_device = {
-	.name			= "serial8250",
-	.id			= PLAT8250_DEV_PLATFORM,
-	.dev			= {
-		.platform_data	= serial_platform_data,
-	},
-};
-
 static int __init omap_init(void)
 {
 	int ret;
+	int i;
 
-	ret = platform_device_register(&serial_device);
+	for (i = 0; i < ARRAY_SIZE(omap_uart); i++) {
+		ret = platform_device_register(&omap_uart[i].pdev);
+		if (ret < 0)
+			goto device_err;
+		if ((cpu_is_omap34xx() && omap_uart[i].padconf) ||
+		    (omap_uart[i].wk_en && omap_uart[i].wk_mask)) {
+			printk(KERN_ERR "%s: Setting init_wakeup\n", __func__);
+			device_init_wakeup(&omap_uart[i].pdev.dev, true);
+		}
+	}
 
 #ifdef CONFIG_PM
-	if (!ret)
-		ret = sysfs_create_file(&serial_device.dev.kobj,
+	for (i = 0; i < ARRAY_SIZE(omap_uart); i++) {
+		ret = sysfs_create_file(&omap_uart[i].pdev.dev.kobj,
 					&sleep_timeout_attr.attr);
+		if (ret < 0)
+			goto sysfs_err;
+	}
+#endif
+	return ret;
+
+#ifdef CONFIG_PM
+sysfs_err:
+	for (i--; i >= 0; i--)
+		sysfs_remove_file(&omap_uart[i].pdev.dev.kobj,
+				&sleep_timeout_attr.attr);
+	i = ARRAY_SIZE(omap_uart);
 #endif
+
+device_err:
+	for (i--; i >= 0; i--)
+		platform_device_unregister(&omap_uart[i].pdev);
 	return ret;
 }
 arch_initcall(omap_init);
-- 
1.6.0.4