drivers/rtc/rtc-omap.c: add support for enabling 32khz clock

[cascardo/linux.git] / drivers / rtc / rtc-omap.c

diff --git a/drivers/rtc/rtc-omap.c b/drivers/rtc/rtc-omap.c
index 26de5f8..03bce13 100644 (file)
--- a/drivers/rtc/rtc-omap.c
+++ b/drivers/rtc/rtc-omap.c
@@ -73,43 +73,52 @@
 #define OMAP_RTC_IRQWAKEEN             0x7c
 
 /* OMAP_RTC_CTRL_REG bit fields: */
-#define OMAP_RTC_CTRL_SPLIT            (1<<7)
-#define OMAP_RTC_CTRL_DISABLE          (1<<6)
-#define OMAP_RTC_CTRL_SET_32_COUNTER   (1<<5)
-#define OMAP_RTC_CTRL_TEST             (1<<4)
-#define OMAP_RTC_CTRL_MODE_12_24       (1<<3)
-#define OMAP_RTC_CTRL_AUTO_COMP                (1<<2)
-#define OMAP_RTC_CTRL_ROUND_30S                (1<<1)
-#define OMAP_RTC_CTRL_STOP             (1<<0)
+#define OMAP_RTC_CTRL_SPLIT            BIT(7)
+#define OMAP_RTC_CTRL_DISABLE          BIT(6)
+#define OMAP_RTC_CTRL_SET_32_COUNTER   BIT(5)
+#define OMAP_RTC_CTRL_TEST             BIT(4)
+#define OMAP_RTC_CTRL_MODE_12_24       BIT(3)
+#define OMAP_RTC_CTRL_AUTO_COMP                BIT(2)
+#define OMAP_RTC_CTRL_ROUND_30S                BIT(1)
+#define OMAP_RTC_CTRL_STOP             BIT(0)
 
 /* OMAP_RTC_STATUS_REG bit fields: */
-#define OMAP_RTC_STATUS_POWER_UP        (1<<7)
-#define OMAP_RTC_STATUS_ALARM           (1<<6)
-#define OMAP_RTC_STATUS_1D_EVENT        (1<<5)
-#define OMAP_RTC_STATUS_1H_EVENT        (1<<4)
-#define OMAP_RTC_STATUS_1M_EVENT        (1<<3)
-#define OMAP_RTC_STATUS_1S_EVENT        (1<<2)
-#define OMAP_RTC_STATUS_RUN             (1<<1)
-#define OMAP_RTC_STATUS_BUSY            (1<<0)
+#define OMAP_RTC_STATUS_POWER_UP       BIT(7)
+#define OMAP_RTC_STATUS_ALARM          BIT(6)
+#define OMAP_RTC_STATUS_1D_EVENT       BIT(5)
+#define OMAP_RTC_STATUS_1H_EVENT       BIT(4)
+#define OMAP_RTC_STATUS_1M_EVENT       BIT(3)
+#define OMAP_RTC_STATUS_1S_EVENT       BIT(2)
+#define OMAP_RTC_STATUS_RUN            BIT(1)
+#define OMAP_RTC_STATUS_BUSY           BIT(0)
 
 /* OMAP_RTC_INTERRUPTS_REG bit fields: */
-#define OMAP_RTC_INTERRUPTS_IT_ALARM    (1<<3)
-#define OMAP_RTC_INTERRUPTS_IT_TIMER    (1<<2)
+#define OMAP_RTC_INTERRUPTS_IT_ALARM   BIT(3)
+#define OMAP_RTC_INTERRUPTS_IT_TIMER   BIT(2)
+
+/* OMAP_RTC_OSC_REG bit fields: */
+#define OMAP_RTC_OSC_32KCLK_EN         BIT(6)
 
 /* OMAP_RTC_IRQWAKEEN bit fields: */
-#define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN    (1<<1)
+#define OMAP_RTC_IRQWAKEEN_ALARM_WAKEEN        BIT(1)
 
 /* OMAP_RTC_KICKER values */
 #define        KICK0_VALUE                     0x83e70b13
 #define        KICK1_VALUE                     0x95a4f1e0
 
-#define        OMAP_RTC_HAS_KICKER             0x1
+#define        OMAP_RTC_HAS_KICKER             BIT(0)
 
 /*
  * Few RTC IP revisions has special WAKE-EN Register to enable Wakeup
  * generation for event Alarm.
  */
-#define        OMAP_RTC_HAS_IRQWAKEEN          0x2
+#define        OMAP_RTC_HAS_IRQWAKEEN          BIT(1)
+
+/*
+ * Some RTC IP revisions (like those in AM335x and DRA7x) need
+ * the 32KHz clock to be explicitly enabled.
+ */
+#define OMAP_RTC_HAS_32KCLK_EN         BIT(2)
 
 static void __iomem    *rtc_base;
 
@@ -319,7 +328,8 @@ static struct platform_device_id omap_rtc_devtype[] = {
        },
        [OMAP_RTC_DATA_AM3352_IDX] = {
                .name   = "am3352-rtc",
-               .driver_data = OMAP_RTC_HAS_KICKER | OMAP_RTC_HAS_IRQWAKEEN,
+               .driver_data = OMAP_RTC_HAS_KICKER | OMAP_RTC_HAS_IRQWAKEEN |
+                              OMAP_RTC_HAS_32KCLK_EN,
        },
        [OMAP_RTC_DATA_DA830_IDX] = {
                .name   = "da830-rtc",
@@ -352,6 +362,12 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
        if (of_id)
                pdev->id_entry = of_id->data;
 
+       id_entry = platform_get_device_id(pdev);
+       if (!id_entry) {
+               dev_err(&pdev->dev, "no matching device entry\n");
+               return -ENODEV;
+       }
+
        omap_rtc_timer = platform_get_irq(pdev, 0);
        if (omap_rtc_timer <= 0) {
                pr_debug("%s: no update irq?\n", pdev->name);
@@ -373,8 +389,7 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
        pm_runtime_enable(&pdev->dev);
        pm_runtime_get_sync(&pdev->dev);
 
-       id_entry = platform_get_device_id(pdev);
-       if (id_entry && (id_entry->driver_data & OMAP_RTC_HAS_KICKER)) {
+       if (id_entry->driver_data & OMAP_RTC_HAS_KICKER) {
                rtc_writel(KICK0_VALUE, OMAP_RTC_KICK0_REG);
                rtc_writel(KICK1_VALUE, OMAP_RTC_KICK1_REG);
        }
@@ -393,6 +408,10 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
         */
        rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
 
+       /* enable RTC functional clock */
+       if (id_entry->driver_data & OMAP_RTC_HAS_32KCLK_EN)
+               rtc_writel(OMAP_RTC_OSC_32KCLK_EN, OMAP_RTC_OSC_REG);
+
        /* clear old status */
        reg = rtc_read(OMAP_RTC_STATUS_REG);
        if (reg & (u8) OMAP_RTC_STATUS_POWER_UP) {
@@ -452,7 +471,7 @@ static int __init omap_rtc_probe(struct platform_device *pdev)
        return 0;
 
 fail0:
-       if (id_entry && (id_entry->driver_data & OMAP_RTC_HAS_KICKER))
+       if (id_entry->driver_data & OMAP_RTC_HAS_KICKER)
                rtc_writel(0, OMAP_RTC_KICK0_REG);
        pm_runtime_put_sync(&pdev->dev);
        pm_runtime_disable(&pdev->dev);
@@ -469,7 +488,7 @@ static int __exit omap_rtc_remove(struct platform_device *pdev)
        /* leave rtc running, but disable irqs */
        rtc_write(0, OMAP_RTC_INTERRUPTS_REG);
 
-       if (id_entry && (id_entry->driver_data & OMAP_RTC_HAS_KICKER))
+       if (id_entry->driver_data & OMAP_RTC_HAS_KICKER)
                rtc_writel(0, OMAP_RTC_KICK0_REG);
 
        /* Disable the clock/module */