3 files changed, 534 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 81adbdbd5042..b136299a237e 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -518,6 +518,16 @@ config RTC_DRV_V3020
           This driver can also be built as a module. If so, the module
           will be called rtc-v3020.
 
+config RTC_DRV_WM831X
+        tristate "Wolfson Microelectronics WM831x RTC"
+        depends on MFD_WM831X
+        help
+          If you say yes here you will get support for the RTC subsystem
+          of the Wolfson Microelectronics WM831X series PMICs.
+
+          This driver can also be built as a module. If so, the module
+          will be called "rtc-wm831x".
+
 config RTC_DRV_WM8350
         tristate "Wolfson Microelectronics WM8350 RTC"
         depends on MFD_WM8350
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 3c0f2b2ac927..f3e573509092 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -74,6 +74,7 @@ obj-$(CONFIG_RTC_DRV_TWL4030)	+= rtc-twl4030.o
 obj-$(CONFIG_RTC_DRV_TX4939)    += rtc-tx4939.o
 obj-$(CONFIG_RTC_DRV_V3020)     += rtc-v3020.o
 obj-$(CONFIG_RTC_DRV_VR41XX)    += rtc-vr41xx.o
+obj-$(CONFIG_RTC_DRV_WM831X)    += rtc-wm831x.o
 obj-$(CONFIG_RTC_DRV_WM8350)    += rtc-wm8350.o
 obj-$(CONFIG_RTC_DRV_X1205)     += rtc-x1205.o
 obj-$(CONFIG_RTC_DRV_PCF50633)  += rtc-pcf50633.o
diff --git a/drivers/rtc/rtc-wm831x.c b/drivers/rtc/rtc-wm831x.c
new file mode 100644
index 000000000000..79795cdf6ed8
--- /dev/null
+++ b/drivers/rtc/rtc-wm831x.c
@@ -0,0 +1,523 @@
+/*
+ *      Real Time Clock driver for Wolfson Microelectronics WM831x
+ *
+ *      Copyright (C) 2009 Wolfson Microelectronics PLC.
+ *
+ *  Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/time.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/interrupt.h>
+#include <linux/ioctl.h>
+#include <linux/completion.h>
+#include <linux/mfd/wm831x/core.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+
+
+/*
+ * R16416 (0x4020) - RTC Write Counter
+ */
+#define WM831X_RTC_WR_CNT_MASK                  0xFFFF  /* RTC_WR_CNT - [15:0] */
+#define WM831X_RTC_WR_CNT_SHIFT                      0  /* RTC_WR_CNT - [15:0] */
+#define WM831X_RTC_WR_CNT_WIDTH                     16  /* RTC_WR_CNT - [15:0] */
+
+/*
+ * R16417 (0x4021) - RTC Time 1
+ */
+#define WM831X_RTC_TIME_MASK                    0xFFFF  /* RTC_TIME - [15:0] */
+#define WM831X_RTC_TIME_SHIFT                        0  /* RTC_TIME - [15:0] */
+#define WM831X_RTC_TIME_WIDTH                       16  /* RTC_TIME - [15:0] */
+
+/*
+ * R16418 (0x4022) - RTC Time 2
+ */
+#define WM831X_RTC_TIME_MASK                    0xFFFF  /* RTC_TIME - [15:0] */
+#define WM831X_RTC_TIME_SHIFT                        0  /* RTC_TIME - [15:0] */
+#define WM831X_RTC_TIME_WIDTH                       16  /* RTC_TIME - [15:0] */
+
+/*
+ * R16419 (0x4023) - RTC Alarm 1
+ */
+#define WM831X_RTC_ALM_MASK                     0xFFFF  /* RTC_ALM - [15:0] */
+#define WM831X_RTC_ALM_SHIFT                         0  /* RTC_ALM - [15:0] */
+#define WM831X_RTC_ALM_WIDTH                        16  /* RTC_ALM - [15:0] */
+
+/*
+ * R16420 (0x4024) - RTC Alarm 2
+ */
+#define WM831X_RTC_ALM_MASK                     0xFFFF  /* RTC_ALM - [15:0] */
+#define WM831X_RTC_ALM_SHIFT                         0  /* RTC_ALM - [15:0] */
+#define WM831X_RTC_ALM_WIDTH                        16  /* RTC_ALM - [15:0] */
+
+/*
+ * R16421 (0x4025) - RTC Control
+ */
+#define WM831X_RTC_VALID                        0x8000  /* RTC_VALID */
+#define WM831X_RTC_VALID_MASK                   0x8000  /* RTC_VALID */
+#define WM831X_RTC_VALID_SHIFT                      15  /* RTC_VALID */
+#define WM831X_RTC_VALID_WIDTH                       1  /* RTC_VALID */
+#define WM831X_RTC_SYNC_BUSY                    0x4000  /* RTC_SYNC_BUSY */
+#define WM831X_RTC_SYNC_BUSY_MASK               0x4000  /* RTC_SYNC_BUSY */
+#define WM831X_RTC_SYNC_BUSY_SHIFT                  14  /* RTC_SYNC_BUSY */
+#define WM831X_RTC_SYNC_BUSY_WIDTH                   1  /* RTC_SYNC_BUSY */
+#define WM831X_RTC_ALM_ENA                      0x0400  /* RTC_ALM_ENA */
+#define WM831X_RTC_ALM_ENA_MASK                 0x0400  /* RTC_ALM_ENA */
+#define WM831X_RTC_ALM_ENA_SHIFT                    10  /* RTC_ALM_ENA */
+#define WM831X_RTC_ALM_ENA_WIDTH                     1  /* RTC_ALM_ENA */
+#define WM831X_RTC_PINT_FREQ_MASK               0x0070  /* RTC_PINT_FREQ - [6:4] */
+#define WM831X_RTC_PINT_FREQ_SHIFT                   4  /* RTC_PINT_FREQ - [6:4] */
+#define WM831X_RTC_PINT_FREQ_WIDTH                   3  /* RTC_PINT_FREQ - [6:4] */
+
+/*
+ * R16422 (0x4026) - RTC Trim
+ */
+#define WM831X_RTC_TRIM_MASK                    0x03FF  /* RTC_TRIM - [9:0] */
+#define WM831X_RTC_TRIM_SHIFT                        0  /* RTC_TRIM - [9:0] */
+#define WM831X_RTC_TRIM_WIDTH                       10  /* RTC_TRIM - [9:0] */
+
+#define WM831X_SET_TIME_RETRIES 5
+#define WM831X_GET_TIME_RETRIES 5
+
+struct wm831x_rtc {
+        struct wm831x *wm831x;
+        struct rtc_device *rtc;
+        unsigned int alarm_enabled:1;
+};
+
+/*
+ * Read current time and date in RTC
+ */
+static int wm831x_rtc_readtime(struct device *dev, struct rtc_time *tm)
+{
+        struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
+        struct wm831x *wm831x = wm831x_rtc->wm831x;
+        u16 time1[2], time2[2];
+        int ret;
+        int count = 0;
+
+        /* Has the RTC been programmed? */
+        ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
+        if (ret < 0) {
+                dev_err(dev, "Failed to read RTC control: %d\n", ret);
+                return ret;
+        }
+        if (!(ret & WM831X_RTC_VALID)) {
+                dev_dbg(dev, "RTC not yet configured\n");
+                return -EINVAL;
+        }
+
+        /* Read twice to make sure we don't read a corrupt, partially
+         * incremented, value.
+         */
+        do {
+                ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
+                                       2, time1);
+                if (ret != 0)
+                        continue;
+
+                ret = wm831x_bulk_read(wm831x, WM831X_RTC_TIME_1,
+                                       2, time2);
+                if (ret != 0)
+                        continue;
+
+                if (memcmp(time1, time2, sizeof(time1)) == 0) {
+                        u32 time = (time1[0] << 16) | time1[1];
+
+                        rtc_time_to_tm(time, tm);
+                        return rtc_valid_tm(tm);
+                }
+
+        } while (++count < WM831X_GET_TIME_RETRIES);
+
+        dev_err(dev, "Timed out reading current time\n");
+
+        return -EIO;
+}
+
+/*
+ * Set current time and date in RTC
+ */
+static int wm831x_rtc_set_mmss(struct device *dev, unsigned long time)
+{
+        struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
+        struct wm831x *wm831x = wm831x_rtc->wm831x;
+        struct rtc_time new_tm;
+        unsigned long new_time;
+        int ret;
+        int count = 0;
+
+        ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_1,
+                               (time >> 16) & 0xffff);
+        if (ret < 0) {
+                dev_err(dev, "Failed to write TIME_1: %d\n", ret);
+                return ret;
+        }
+
+        ret = wm831x_reg_write(wm831x, WM831X_RTC_TIME_2, time & 0xffff);
+        if (ret < 0) {
+                dev_err(dev, "Failed to write TIME_2: %d\n", ret);
+                return ret;
+        }
+
+        /* Wait for the update to complete - should happen first time
+         * round but be conservative.
+         */
+        do {
+                msleep(1);
+
+                ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
+                if (ret < 0)
+                        ret = WM831X_RTC_SYNC_BUSY;
+        } while (!(ret & WM831X_RTC_SYNC_BUSY) &&
+                 ++count < WM831X_SET_TIME_RETRIES);
+
+        if (ret & WM831X_RTC_SYNC_BUSY) {
+                dev_err(dev, "Timed out writing RTC update\n");
+                return -EIO;
+        }
+
+        /* Check that the update was accepted; security features may
+         * have caused the update to be ignored.
+         */
+        ret = wm831x_rtc_readtime(dev, &new_tm);
+        if (ret < 0)
+                return ret;
+
+        ret = rtc_tm_to_time(&new_tm, &new_time);
+        if (ret < 0) {
+                dev_err(dev, "Failed to convert time: %d\n", ret);
+                return ret;
+        }
+
+        /* Allow a second of change in case of tick */
+        if (new_time - time > 1) {
+                dev_err(dev, "RTC update not permitted by hardware\n");
+                return -EPERM;
+        }
+
+        return 0;
+}
+
+/*
+ * Read alarm time and date in RTC
+ */
+static int wm831x_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+        struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
+        int ret;
+        u16 data[2];
+        u32 time;
+
+        ret = wm831x_bulk_read(wm831x_rtc->wm831x, WM831X_RTC_ALARM_1,
+                               2, data);
+        if (ret != 0) {
+                dev_err(dev, "Failed to read alarm time: %d\n", ret);
+                return ret;
+        }
+
+        time = (data[0] << 16) | data[1];
+
+        rtc_time_to_tm(time, &alrm->time);
+
+        ret = wm831x_reg_read(wm831x_rtc->wm831x, WM831X_RTC_CONTROL);
+        if (ret < 0) {
+                dev_err(dev, "Failed to read RTC control: %d\n", ret);
+                return ret;
+        }
+
+        if (ret & WM831X_RTC_ALM_ENA)
+                alrm->enabled = 1;
+        else
+                alrm->enabled = 0;
+
+        return 0;
+}
+
+static int wm831x_rtc_stop_alarm(struct wm831x_rtc *wm831x_rtc)
+{
+        wm831x_rtc->alarm_enabled = 0;
+
+        return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
+                               WM831X_RTC_ALM_ENA, 0);
+}
+
+static int wm831x_rtc_start_alarm(struct wm831x_rtc *wm831x_rtc)
+{
+        wm831x_rtc->alarm_enabled = 1;
+
+        return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
+                               WM831X_RTC_ALM_ENA, WM831X_RTC_ALM_ENA);
+}
+
+static int wm831x_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+        struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
+        struct wm831x *wm831x = wm831x_rtc->wm831x;
+        int ret;
+        unsigned long time;
+
+        ret = rtc_tm_to_time(&alrm->time, &time);
+        if (ret < 0) {
+                dev_err(dev, "Failed to convert time: %d\n", ret);
+                return ret;
+        }
+
+        ret = wm831x_rtc_stop_alarm(wm831x_rtc);
+        if (ret < 0) {
+                dev_err(dev, "Failed to stop alarm: %d\n", ret);
+                return ret;
+        }
+
+        ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_1,
+                               (time >> 16) & 0xffff);
+        if (ret < 0) {
+                dev_err(dev, "Failed to write ALARM_1: %d\n", ret);
+                return ret;
+        }
+
+        ret = wm831x_reg_write(wm831x, WM831X_RTC_ALARM_2, time & 0xffff);
+        if (ret < 0) {
+                dev_err(dev, "Failed to write ALARM_2: %d\n", ret);
+                return ret;
+        }
+
+        if (alrm->enabled) {
+                ret = wm831x_rtc_start_alarm(wm831x_rtc);
+                if (ret < 0) {
+                        dev_err(dev, "Failed to start alarm: %d\n", ret);
+                        return ret;
+                }
+        }
+
+        return 0;
+}
+
+static int wm831x_rtc_alarm_irq_enable(struct device *dev,
+                                       unsigned int enabled)
+{
+        struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
+
+        if (enabled)
+                return wm831x_rtc_start_alarm(wm831x_rtc);
+        else
+                return wm831x_rtc_stop_alarm(wm831x_rtc);
+}
+
+static int wm831x_rtc_update_irq_enable(struct device *dev,
+                                        unsigned int enabled)
+{
+        struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(dev);
+        int val;
+
+        if (enabled)
+                val = 1 << WM831X_RTC_PINT_FREQ_SHIFT;
+        else
+                val = 0;
+
+        return wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
+                               WM831X_RTC_PINT_FREQ_MASK, val);
+}
+
+static irqreturn_t wm831x_alm_irq(int irq, void *data)
+{
+        struct wm831x_rtc *wm831x_rtc = data;
+
+        rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF | RTC_AF);
+
+        return IRQ_HANDLED;
+}
+
+static irqreturn_t wm831x_per_irq(int irq, void *data)
+{
+        struct wm831x_rtc *wm831x_rtc = data;
+
+        rtc_update_irq(wm831x_rtc->rtc, 1, RTC_IRQF | RTC_UF);
+
+        return IRQ_HANDLED;
+}
+
+static const struct rtc_class_ops wm831x_rtc_ops = {
+        .read_time = wm831x_rtc_readtime,
+        .set_mmss = wm831x_rtc_set_mmss,
+        .read_alarm = wm831x_rtc_readalarm,
+        .set_alarm = wm831x_rtc_setalarm,
+        .alarm_irq_enable = wm831x_rtc_alarm_irq_enable,
+        .update_irq_enable = wm831x_rtc_update_irq_enable,
+};
+
+#ifdef CONFIG_PM
+/* Turn off the alarm if it should not be a wake source. */
+static int wm831x_rtc_suspend(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
+        int ret, enable;
+
+        if (wm831x_rtc->alarm_enabled && device_may_wakeup(&pdev->dev))
+                enable = WM831X_RTC_ALM_ENA;
+        else
+                enable = 0;
+
+        ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
+                              WM831X_RTC_ALM_ENA, enable);
+        if (ret != 0)
+                dev_err(&pdev->dev, "Failed to update RTC alarm: %d\n", ret);
+
+        return 0;
+}
+
+/* Enable the alarm if it should be enabled (in case it was disabled to
+ * prevent use as a wake source).
+ */
+static int wm831x_rtc_resume(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
+        int ret;
+
+        if (wm831x_rtc->alarm_enabled) {
+                ret = wm831x_rtc_start_alarm(wm831x_rtc);
+                if (ret != 0)
+                        dev_err(&pdev->dev,
+                                "Failed to restart RTC alarm: %d\n", ret);
+        }
+
+        return 0;
+}
+
+/* Unconditionally disable the alarm */
+static int wm831x_rtc_freeze(struct device *dev)
+{
+        struct platform_device *pdev = to_platform_device(dev);
+        struct wm831x_rtc *wm831x_rtc = dev_get_drvdata(&pdev->dev);
+        int ret;
+
+        ret = wm831x_set_bits(wm831x_rtc->wm831x, WM831X_RTC_CONTROL,
+                              WM831X_RTC_ALM_ENA, 0);
+        if (ret != 0)
+                dev_err(&pdev->dev, "Failed to stop RTC alarm: %d\n", ret);
+
+        return 0;
+}
+#else
+#define wm831x_rtc_suspend NULL
+#define wm831x_rtc_resume NULL
+#define wm831x_rtc_freeze NULL
+#endif
+
+static int wm831x_rtc_probe(struct platform_device *pdev)
+{
+        struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
+        struct wm831x_rtc *wm831x_rtc;
+        int per_irq = platform_get_irq_byname(pdev, "PER");
+        int alm_irq = platform_get_irq_byname(pdev, "ALM");
+        int ret = 0;
+
+        wm831x_rtc = kzalloc(sizeof(*wm831x_rtc), GFP_KERNEL);
+        if (wm831x_rtc == NULL)
+                return -ENOMEM;
+
+        platform_set_drvdata(pdev, wm831x_rtc);
+        wm831x_rtc->wm831x = wm831x;
+
+        ret = wm831x_reg_read(wm831x, WM831X_RTC_CONTROL);
+        if (ret < 0) {
+                dev_err(&pdev->dev, "Failed to read RTC control: %d\n", ret);
+                goto err;
+        }
+        if (ret & WM831X_RTC_ALM_ENA)
+                wm831x_rtc->alarm_enabled = 1;
+
+        device_init_wakeup(&pdev->dev, 1);
+
+        wm831x_rtc->rtc = rtc_device_register("wm831x", &pdev->dev,
+                                              &wm831x_rtc_ops, THIS_MODULE);
+        if (IS_ERR(wm831x_rtc->rtc)) {
+                ret = PTR_ERR(wm831x_rtc->rtc);
+                goto err;
+        }
+
+        ret = wm831x_request_irq(wm831x, per_irq, wm831x_per_irq,
+                                 IRQF_TRIGGER_RISING, "wm831x_rtc_per",
+                                 wm831x_rtc);
+        if (ret != 0) {
+                dev_err(&pdev->dev, "Failed to request periodic IRQ %d: %d\n",
+                        per_irq, ret);
+        }
+
+        ret = wm831x_request_irq(wm831x, alm_irq, wm831x_alm_irq,
+                                 IRQF_TRIGGER_RISING, "wm831x_rtc_alm",
+                                 wm831x_rtc);
+        if (ret != 0) {
+                dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
+                        alm_irq, ret);
+        }
+
+        return 0;
+
+err:
+        kfree(wm831x_rtc);
+        return ret;
+}
+
+static int __devexit wm831x_rtc_remove(struct platform_device *pdev)
+{
+        struct wm831x_rtc *wm831x_rtc = platform_get_drvdata(pdev);
+        int per_irq = platform_get_irq_byname(pdev, "PER");
+        int alm_irq = platform_get_irq_byname(pdev, "ALM");
+
+        wm831x_free_irq(wm831x_rtc->wm831x, alm_irq, wm831x_rtc);
+        wm831x_free_irq(wm831x_rtc->wm831x, per_irq, wm831x_rtc);
+        rtc_device_unregister(wm831x_rtc->rtc);
+        kfree(wm831x_rtc);
+
+        return 0;
+}
+
+static struct dev_pm_ops wm831x_rtc_pm_ops = {
+        .suspend = wm831x_rtc_suspend,
+        .resume = wm831x_rtc_resume,
+
+        .freeze = wm831x_rtc_freeze,
+        .thaw = wm831x_rtc_resume,
+        .restore = wm831x_rtc_resume,
+
+        .poweroff = wm831x_rtc_suspend,
+};
+
+static struct platform_driver wm831x_rtc_driver = {
+        .probe = wm831x_rtc_probe,
+        .remove = __devexit_p(wm831x_rtc_remove),
+        .driver = {
+                .name = "wm831x-rtc",
+                .pm = &wm831x_rtc_pm_ops,
+        },
+};
+
+static int __init wm831x_rtc_init(void)
+{
+        return platform_driver_register(&wm831x_rtc_driver);
+}
+module_init(wm831x_rtc_init);
+
+static void __exit wm831x_rtc_exit(void)
+{
+        platform_driver_unregister(&wm831x_rtc_driver);
+}
+module_exit(wm831x_rtc_exit);
+
+MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
+MODULE_DESCRIPTION("RTC driver for the WM831x series PMICs");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:wm831x-rtc");