rtc: Add an RTC driver for the Oki MSM6242

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Alessandro Zummo <alessandro.zummo@towertech.it>

3 files changed, 279 insertions, 0 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 3c20dae43ce2..16c8268da33c 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -509,6 +509,15 @@ config RTC_DRV_M48T59
           This driver can also be built as a module, if so, the module
           will be called "rtc-m48t59".
 
+config RTC_DRV_MSM6242
+        tristate "Oki MSM6242"
+        help
+          If you say yes here you get support for the Oki MSM6242
+          timekeeping chip. It is used in some Amiga models (e.g. A2000).
+
+          This driver can also be built as a module. If so, the module
+          will be called rtc-msm6242.
+
 config RTC_MXC
         tristate "Freescale MXC Real Time Clock"
         depends on ARCH_MXC
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index aa3fbd5517a1..7e704f67199b 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -52,6 +52,7 @@ obj-$(CONFIG_RTC_DRV_M48T86)	+= rtc-m48t86.o
 obj-$(CONFIG_RTC_MXC)           += rtc-mxc.o
 obj-$(CONFIG_RTC_DRV_MAX6900)   += rtc-max6900.o
 obj-$(CONFIG_RTC_DRV_MAX6902)   += rtc-max6902.o
+obj-$(CONFIG_RTC_DRV_MSM6242)   += rtc-msm6242.o
 obj-$(CONFIG_RTC_DRV_MV)        += rtc-mv.o
 obj-$(CONFIG_RTC_DRV_OMAP)      += rtc-omap.o
 obj-$(CONFIG_RTC_DRV_PCAP)      += rtc-pcap.o
diff --git a/drivers/rtc/rtc-msm6242.c b/drivers/rtc/rtc-msm6242.c
new file mode 100644
index 000000000000..5f5968a48925
--- /dev/null
+++ b/drivers/rtc/rtc-msm6242.c
@@ -0,0 +1,269 @@
+/*
+ *  Oki MSM6242 RTC Driver
+ *
+ *  Copyright 2009 Geert Uytterhoeven
+ *
+ *  Based on the A2000 TOD code in arch/m68k/amiga/config.c
+ *  Copyright (C) 1993 Hamish Macdonald
+ */
+
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+
+enum {
+        MSM6242_SECOND1         = 0x0,  /* 1-second digit register */
+        MSM6242_SECOND10        = 0x1,  /* 10-second digit register */
+        MSM6242_MINUTE1         = 0x2,  /* 1-minute digit register */
+        MSM6242_MINUTE10        = 0x3,  /* 10-minute digit register */
+        MSM6242_HOUR1           = 0x4,  /* 1-hour digit register */
+        MSM6242_HOUR10          = 0x5,  /* PM/AM, 10-hour digit register */
+        MSM6242_DAY1            = 0x6,  /* 1-day digit register */
+        MSM6242_DAY10           = 0x7,  /* 10-day digit register */
+        MSM6242_MONTH1          = 0x8,  /* 1-month digit register */
+        MSM6242_MONTH10         = 0x9,  /* 10-month digit register */
+        MSM6242_YEAR1           = 0xa,  /* 1-year digit register */
+        MSM6242_YEAR10          = 0xb,  /* 10-year digit register */
+        MSM6242_WEEK            = 0xc,  /* Week register */
+        MSM6242_CD              = 0xd,  /* Control Register D */
+        MSM6242_CE              = 0xe,  /* Control Register E */
+        MSM6242_CF              = 0xf,  /* Control Register F */
+};
+
+#define MSM6242_HOUR10_AM       (0 << 2)
+#define MSM6242_HOUR10_PM       (1 << 2)
+#define MSM6242_HOUR10_HR_MASK  (3 << 0)
+
+#define MSM6242_WEEK_SUNDAY     0
+#define MSM6242_WEEK_MONDAY     1
+#define MSM6242_WEEK_TUESDAY    2
+#define MSM6242_WEEK_WEDNESDAY  3
+#define MSM6242_WEEK_THURSDAY   4
+#define MSM6242_WEEK_FRIDAY     5
+#define MSM6242_WEEK_SATURDAY   6
+
+#define MSM6242_CD_30_S_ADJ     (1 << 3)        /* 30-second adjustment */
+#define MSM6242_CD_IRQ_FLAG     (1 << 2)
+#define MSM6242_CD_BUSY         (1 << 1)
+#define MSM6242_CD_HOLD         (1 << 0)
+
+#define MSM6242_CE_T_MASK       (3 << 2)
+#define MSM6242_CE_T_64HZ       (0 << 2)        /* period 1/64 second */
+#define MSM6242_CE_T_1HZ        (1 << 2)        /* period 1 second */
+#define MSM6242_CE_T_1MINUTE    (2 << 2)        /* period 1 minute */
+#define MSM6242_CE_T_1HOUR      (3 << 2)        /* period 1 hour */
+
+#define MSM6242_CE_ITRPT_STND   (1 << 1)
+#define MSM6242_CE_MASK         (1 << 0)        /* STD.P output control */
+
+#define MSM6242_CF_TEST         (1 << 3)
+#define MSM6242_CF_12H          (0 << 2)
+#define MSM6242_CF_24H          (1 << 2)
+#define MSM6242_CF_STOP         (1 << 1)
+#define MSM6242_CF_REST         (1 << 0)        /* reset */
+
+
+struct msm6242_priv {
+        u32 __iomem *regs;
+        struct rtc_device *rtc;
+};
+
+static inline unsigned int msm6242_read(struct msm6242_priv *priv,
+                                       unsigned int reg)
+{
+        return __raw_readl(&priv->regs[reg]) & 0xf;
+}
+
+static inline void msm6242_write(struct msm6242_priv *priv, unsigned int val,
+                                unsigned int reg)
+{
+        return __raw_writel(val, &priv->regs[reg]);
+}
+
+static inline void msm6242_set(struct msm6242_priv *priv, unsigned int val,
+                               unsigned int reg)
+{
+        msm6242_write(priv, msm6242_read(priv, reg) | val, reg);
+}
+
+static inline void msm6242_clear(struct msm6242_priv *priv, unsigned int val,
+                                 unsigned int reg)
+{
+        msm6242_write(priv, msm6242_read(priv, reg) & ~val, reg);
+}
+
+static void msm6242_lock(struct msm6242_priv *priv)
+{
+        int cnt = 5;
+
+        msm6242_set(priv, MSM6242_CD_HOLD, MSM6242_CD);
+
+        while ((msm6242_read(priv, MSM6242_CD) & MSM6242_CD_BUSY) && cnt) {
+                msm6242_clear(priv, MSM6242_CD_HOLD, MSM6242_CD);
+                udelay(70);
+                msm6242_set(priv, MSM6242_CD_HOLD, MSM6242_CD);
+                cnt--;
+        }
+
+        if (!cnt)
+                pr_warning("msm6242: timed out waiting for RTC (0x%x)\n",
+                           msm6242_read(priv, MSM6242_CD));
+}
+
+static void msm6242_unlock(struct msm6242_priv *priv)
+{
+        msm6242_clear(priv, MSM6242_CD_HOLD, MSM6242_CD);
+}
+
+static int msm6242_read_time(struct device *dev, struct rtc_time *tm)
+{
+        struct msm6242_priv *priv = dev_get_drvdata(dev);
+
+        msm6242_lock(priv);
+
+        tm->tm_sec  = msm6242_read(priv, MSM6242_SECOND10) * 10 +
+                      msm6242_read(priv, MSM6242_SECOND1);
+        tm->tm_min  = msm6242_read(priv, MSM6242_MINUTE10) * 10 +
+                      msm6242_read(priv, MSM6242_MINUTE1);
+        tm->tm_hour = (msm6242_read(priv, MSM6242_HOUR10 & 3)) * 10 +
+                      msm6242_read(priv, MSM6242_HOUR1);
+        tm->tm_mday = msm6242_read(priv, MSM6242_DAY10) * 10 +
+                      msm6242_read(priv, MSM6242_DAY1);
+        tm->tm_wday = msm6242_read(priv, MSM6242_WEEK);
+        tm->tm_mon  = msm6242_read(priv, MSM6242_MONTH10) * 10 +
+                      msm6242_read(priv, MSM6242_MONTH1) - 1;
+        tm->tm_year = msm6242_read(priv, MSM6242_YEAR10) * 10 +
+                      msm6242_read(priv, MSM6242_YEAR1);
+        if (tm->tm_year <= 69)
+                tm->tm_year += 100;
+
+        if (!(msm6242_read(priv, MSM6242_CF) & MSM6242_CF_24H)) {
+                unsigned int pm = msm6242_read(priv, MSM6242_HOUR10) &
+                                  MSM6242_HOUR10_PM;
+                if (!pm && tm->tm_hour == 12)
+                        tm->tm_hour = 0;
+                else if (pm && tm->tm_hour != 12)
+                        tm->tm_hour += 12;
+        }
+
+        msm6242_unlock(priv);
+
+        return rtc_valid_tm(tm);
+}
+
+static int msm6242_set_time(struct device *dev, struct rtc_time *tm)
+{
+        struct msm6242_priv *priv = dev_get_drvdata(dev);
+
+        msm6242_lock(priv);
+
+        msm6242_write(priv, tm->tm_sec / 10, MSM6242_SECOND10);
+        msm6242_write(priv, tm->tm_sec % 10, MSM6242_SECOND1);
+        msm6242_write(priv, tm->tm_min / 10, MSM6242_MINUTE10);
+        msm6242_write(priv, tm->tm_min % 10, MSM6242_MINUTE1);
+        if (msm6242_read(priv, MSM6242_CF) & MSM6242_CF_24H)
+                msm6242_write(priv, tm->tm_hour / 10, MSM6242_HOUR10);
+        else if (tm->tm_hour >= 12)
+                msm6242_write(priv, MSM6242_HOUR10_PM + (tm->tm_hour - 12) / 10,
+                              MSM6242_HOUR10);
+        else
+                msm6242_write(priv, tm->tm_hour / 10, MSM6242_HOUR10);
+        msm6242_write(priv, tm->tm_hour % 10, MSM6242_HOUR1);
+        msm6242_write(priv, tm->tm_mday / 10, MSM6242_DAY10);
+        msm6242_write(priv, tm->tm_mday % 10, MSM6242_DAY1);
+        if (tm->tm_wday != -1)
+                msm6242_write(priv, tm->tm_wday, MSM6242_WEEK);
+        msm6242_write(priv, (tm->tm_mon + 1) / 10, MSM6242_MONTH10);
+        msm6242_write(priv, (tm->tm_mon + 1) % 10, MSM6242_MONTH1);
+        if (tm->tm_year >= 100)
+                tm->tm_year -= 100;
+        msm6242_write(priv, tm->tm_year / 10, MSM6242_YEAR10);
+        msm6242_write(priv, tm->tm_year % 10, MSM6242_YEAR1);
+
+        msm6242_unlock(priv);
+        return 0;
+}
+
+static const struct rtc_class_ops msm6242_rtc_ops = {
+        .read_time      = msm6242_read_time,
+        .set_time       = msm6242_set_time,
+};
+
+static int __init msm6242_rtc_probe(struct platform_device *dev)
+{
+        struct resource *res;
+        struct msm6242_priv *priv;
+        struct rtc_device *rtc;
+        int error;
+
+        res = platform_get_resource(dev, IORESOURCE_MEM, 0);
+        if (!res)
+                return -ENODEV;
+
+        priv = kzalloc(sizeof(*priv), GFP_KERNEL);
+        if (!priv)
+                return -ENOMEM;
+
+        priv->regs = ioremap(res->start, resource_size(res));
+        if (!priv->regs) {
+                error = -ENOMEM;
+                goto out_free_priv;
+        }
+
+        rtc = rtc_device_register("rtc-msm6242", &dev->dev, &msm6242_rtc_ops,
+                                  THIS_MODULE);
+        if (IS_ERR(rtc)) {
+                error = PTR_ERR(rtc);
+                goto out_unmap;
+        }
+
+        priv->rtc = rtc;
+        platform_set_drvdata(dev, priv);
+        return 0;
+
+out_unmap:
+        iounmap(priv->regs);
+out_free_priv:
+        kfree(priv);
+        return error;
+}
+
+static int __exit msm6242_rtc_remove(struct platform_device *dev)
+{
+        struct msm6242_priv *priv = platform_get_drvdata(dev);
+
+        rtc_device_unregister(priv->rtc);
+        iounmap(priv->regs);
+        kfree(priv);
+        return 0;
+}
+
+static struct platform_driver msm6242_rtc_driver = {
+        .driver = {
+                .name   = "rtc-msm6242",
+                .owner  = THIS_MODULE,
+        },
+        .remove = __exit_p(msm6242_rtc_remove),
+};
+
+static int __init msm6242_rtc_init(void)
+{
+        return platform_driver_probe(&msm6242_rtc_driver, msm6242_rtc_probe);
+}
+
+static void __exit msm6242_rtc_fini(void)
+{
+        platform_driver_unregister(&msm6242_rtc_driver);
+}
+
+module_init(msm6242_rtc_init);
+module_exit(msm6242_rtc_fini);
+
+MODULE_AUTHOR("Geert Uytterhoeven <geert@linux-m68k.org>");
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("Oki MSM6242 RTC driver");
+MODULE_ALIAS("platform:rtc-msm6242");