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>

diff --git a/arch/arm/mach-omap2/serial.c b/arch/arm/mach-omap2/serial.c
index 5352d05b42d6dde40f402adaf401f7d71ad78cf4..6f35a7e4893f4345790c4b52e7370cc747138b48 100644 (file)
--- 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);
+               }
+       }
 }
-