OMAP2/3/4: UART: Allow per-UART disabling wakeup for serial ports

This patch causes the OMAP uarts to honor the sysfs power/wakeup file
for IOPAD wakeups. 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.

By default, IOPAD wakeups are enabled for each UART.  To disable,

  # echo disabled > /sys/devices/platform/serial8250.0/power/wakeup

Where serial8250.0 can be replaced by .1, or .2 to control the other
ports.

Original idea and original patch from Russ Dill <russ.dill@gmail.com>

Cc: Russ Dill <russ.dill@gmail.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

1 files changed, 116 insertions, 58 deletions

diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index 5352d05b42d6..6f35a7e4893f 100644
--- a/arch/arm/mach-omap2/serial.c
+++ b/arch/arm/mach-omap2/serial.c
@@ -54,6 +54,7 @@ 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;
@@ -68,10 +69,9 @@ 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,
@@ -81,6 +81,12 @@ 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,
@@ -89,6 +95,12 @@ 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,
@@ -217,6 +229,40 @@ static inline void omap_uart_disable_clocks(struct omap_uart_state *uart)
         clk_disable(uart->fck);
 }
 
+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)
 {
@@ -246,6 +292,11 @@ static void omap_uart_block_sleep(struct omap_uart_state *uart)
 
 static void omap_uart_allow_sleep(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;
 
@@ -292,7 +343,6 @@ void omap_uart_resume_idle(int num)
                         /* Check for normal UART wakeup */
                         if (__raw_readl(uart->wk_st) & uart->wk_mask)
                                 omap_uart_block_sleep(uart);
-
                         return;
                 }
         }
@@ -346,16 +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);
@@ -413,22 +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);
@@ -449,54 +480,81 @@ void omap_uart_enable_irqs(int enable)
         }
 }
 
-static ssize_t sleep_timeout_show(struct kobject *kobj,
-                                  struct kobj_attribute *attr,
+static ssize_t sleep_timeout_show(struct device *dev,
+                                  struct device_attribute *attr,
                                   char *buf)
 {
-        return sprintf(buf, "%u\n", sleep_timeout / HZ);
+        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,
+static ssize_t sleep_timeout_store(struct device *dev,
+                                   struct device_attribute *attr,
                                    const char *buf, size_t n)
 {
-        struct omap_uart_state *uart;
+        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;
-                if (uart->timeout)
-                        mod_timer(&uart->timer, jiffies + uart->timeout);
-                else
-                        /* A zero value means disable timeout feature */
-                        omap_uart_block_sleep(uart);
-        }
+
+        uart->timeout = value * HZ;
+        if (uart->timeout)
+                mod_timer(&uart->timer, jiffies + uart->timeout);
+        else
+                /* A zero value means disable timeout feature */
+                omap_uart_block_sleep(uart);
+
         return n;
 }
 
-static struct kobj_attribute sleep_timeout_attr =
-        __ATTR(sleep_timeout, 0644, sleep_timeout_show, sleep_timeout_store);
-
+DEVICE_ATTR(sleep_timeout, 0644, sleep_timeout_show, sleep_timeout_store);
+#define DEV_CREATE_FILE(dev, attr) WARN_ON(device_create_file(dev, attr))
 #else
 static inline void omap_uart_idle_init(struct omap_uart_state *uart) {}
+#define DEV_CREATE_FILE(dev, attr)
 #endif /* CONFIG_PM */
 
-static struct platform_device serial_device = {
-        .name                   = "serial8250",
-        .id                     = PLAT8250_DEV_PLATFORM,
-        .dev                    = {
-                .platform_data  = serial_platform_data,
+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, err;
+        int i;
         const struct omap_uart_config *info;
         char name[16];
 
@@ -512,8 +570,10 @@ 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 platform_device *pdev = &uart->pdev;
+                struct device *dev = &pdev->dev;
+                struct plat_serial8250_port *p = dev->platform_data;
 
                 if (!(info->enabled_uarts & (1 << i))) {
                         p->membase = NULL;
@@ -549,15 +609,13 @@ void __init omap_serial_init(void)
                 omap_uart_enable_clocks(uart);
                 omap_uart_reset(uart);
                 omap_uart_idle_init(uart);
-        }
-
-        err = platform_device_register(&serial_device);
-
-#ifdef CONFIG_PM
-        if (!err)
-                err = sysfs_create_file(&serial_device.dev.kobj,
-                                        &sleep_timeout_attr.attr);
-#endif
 
+                if (WARN_ON(platform_device_register(pdev)))
+                        continue;
+                if ((cpu_is_omap34xx() && uart->padconf) ||
+                    (uart->wk_en && uart->wk_mask)) {
+                        device_init_wakeup(dev, true);
+                        DEV_CREATE_FILE(dev, &dev_attr_sleep_timeout);
+                }
+        }
 }
-