1 files changed, 109 insertions, 29 deletions

diff --git a/drivers/rtc/rtc-at91sam9.c b/drivers/rtc/rtc-at91sam9.c
index 596374304532..abac38abd38e 100644
--- a/drivers/rtc/rtc-at91sam9.c
+++ b/drivers/rtc/rtc-at91sam9.c
@@ -21,10 +21,9 @@
 #include <linux/slab.h>
 #include <linux/platform_data/atmel.h>
 #include <linux/io.h>
-
-#include <mach/at91_rtt.h>
-#include <mach/cpu.h>
-#include <mach/hardware.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
+#include <linux/clk.h>
 
 /*
  * This driver uses two configurable hardware resources that live in the
@@ -47,6 +46,22 @@
  * registers available, likewise usable for more than "RTC" support.
  */
 
+#define AT91_RTT_MR             0x00                    /* Real-time Mode Register */
+#define AT91_RTT_RTPRES         (0xffff << 0)           /* Real-time Timer Prescaler Value */
+#define AT91_RTT_ALMIEN         (1 << 16)               /* Alarm Interrupt Enable */
+#define AT91_RTT_RTTINCIEN      (1 << 17)               /* Real Time Timer Increment Interrupt Enable */
+#define AT91_RTT_RTTRST         (1 << 18)               /* Real Time Timer Restart */
+
+#define AT91_RTT_AR             0x04                    /* Real-time Alarm Register */
+#define AT91_RTT_ALMV           (0xffffffff)            /* Alarm Value */
+
+#define AT91_RTT_VR             0x08                    /* Real-time Value Register */
+#define AT91_RTT_CRTV           (0xffffffff)            /* Current Real-time Value */
+
+#define AT91_RTT_SR             0x0c                    /* Real-time Status Register */
+#define AT91_RTT_ALMS           (1 << 0)                /* Real-time Alarm Status */
+#define AT91_RTT_RTTINC         (1 << 1)                /* Real-time Timer Increment */
+
 /*
  * We store ALARM_DISABLED in ALMV to record that no alarm is set.
  * It's also the reset value for that field.
@@ -58,19 +73,30 @@ struct sam9_rtc {
         void __iomem            *rtt;
         struct rtc_device       *rtcdev;
         u32                     imr;
-        void __iomem            *gpbr;
+        struct regmap           *gpbr;
+        unsigned int            gpbr_offset;
         int                     irq;
+        struct clk              *sclk;
 };
 
 #define rtt_readl(rtc, field) \
-        __raw_readl((rtc)->rtt + AT91_RTT_ ## field)
+        readl((rtc)->rtt + AT91_RTT_ ## field)
 #define rtt_writel(rtc, field, val) \
-        __raw_writel((val), (rtc)->rtt + AT91_RTT_ ## field)
+        writel((val), (rtc)->rtt + AT91_RTT_ ## field)
+
+static inline unsigned int gpbr_readl(struct sam9_rtc *rtc)
+{
+        unsigned int val;
+
+        regmap_read(rtc->gpbr, rtc->gpbr_offset, &val);
 
-#define gpbr_readl(rtc) \
-        __raw_readl((rtc)->gpbr)
-#define gpbr_writel(rtc, val) \
-        __raw_writel((val), (rtc)->gpbr)
+        return val;
+}
+
+static inline void gpbr_writel(struct sam9_rtc *rtc, unsigned int val)
+{
+        regmap_write(rtc->gpbr, rtc->gpbr_offset, val);
+}
 
 /*
  * Read current time and date in RTC
@@ -287,22 +313,22 @@ static const struct rtc_class_ops at91_rtc_ops = {
         .alarm_irq_enable = at91_rtc_alarm_irq_enable,
 };
 
+static struct regmap_config gpbr_regmap_config = {
+        .reg_bits = 32,
+        .val_bits = 32,
+        .reg_stride = 4,
+};
+
 /*
  * Initialize and install RTC driver
  */
 static int at91_rtc_probe(struct platform_device *pdev)
 {
-        struct resource *r, *r_gpbr;
+        struct resource *r;
         struct sam9_rtc *rtc;
         int             ret, irq;
         u32             mr;
-
-        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-        r_gpbr = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-        if (!r || !r_gpbr) {
-                dev_err(&pdev->dev, "need 2 ressources\n");
-                return -ENODEV;
-        }
+        unsigned int    sclk_rate;
 
         irq = platform_get_irq(pdev, 0);
         if (irq < 0) {
@@ -321,24 +347,66 @@ static int at91_rtc_probe(struct platform_device *pdev)
                 device_init_wakeup(&pdev->dev, 1);
 
         platform_set_drvdata(pdev, rtc);
-        rtc->rtt = devm_ioremap(&pdev->dev, r->start, resource_size(r));
-        if (!rtc->rtt) {
-                dev_err(&pdev->dev, "failed to map registers, aborting.\n");
-                return -ENOMEM;
+
+        r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+        rtc->rtt = devm_ioremap_resource(&pdev->dev, r);
+        if (IS_ERR(rtc->rtt))
+                return PTR_ERR(rtc->rtt);
+
+        if (!pdev->dev.of_node) {
+                /*
+                 * TODO: Remove this code chunk when removing non DT board
+                 * support. Remember to remove the gpbr_regmap_config
+                 * variable too.
+                 */
+                void __iomem *gpbr;
+
+                r = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+                gpbr = devm_ioremap_resource(&pdev->dev, r);
+                if (IS_ERR(gpbr))
+                        return PTR_ERR(gpbr);
+
+                rtc->gpbr = regmap_init_mmio(NULL, gpbr,
+                                             &gpbr_regmap_config);
+        } else {
+                struct of_phandle_args args;
+
+                ret = of_parse_phandle_with_fixed_args(pdev->dev.of_node,
+                                                "atmel,rtt-rtc-time-reg", 1, 0,
+                                                &args);
+                if (ret)
+                        return ret;
+
+                rtc->gpbr = syscon_node_to_regmap(args.np);
+                rtc->gpbr_offset = args.args[0];
         }
 
-        rtc->gpbr = devm_ioremap(&pdev->dev, r_gpbr->start,
-                                resource_size(r_gpbr));
-        if (!rtc->gpbr) {
-                dev_err(&pdev->dev, "failed to map gpbr registers, aborting.\n");
+        if (IS_ERR(rtc->gpbr)) {
+                dev_err(&pdev->dev, "failed to retrieve gpbr regmap, aborting.\n");
                 return -ENOMEM;
         }
 
+        rtc->sclk = devm_clk_get(&pdev->dev, NULL);
+        if (IS_ERR(rtc->sclk))
+                return PTR_ERR(rtc->sclk);
+
+        sclk_rate = clk_get_rate(rtc->sclk);
+        if (!sclk_rate || sclk_rate > AT91_RTT_RTPRES) {
+                dev_err(&pdev->dev, "Invalid slow clock rate\n");
+                return -EINVAL;
+        }
+
+        ret = clk_prepare_enable(rtc->sclk);
+        if (ret) {
+                dev_err(&pdev->dev, "Could not enable slow clock\n");
+                return ret;
+        }
+
         mr = rtt_readl(rtc, MR);
 
         /* unless RTT is counting at 1 Hz, re-initialize it */
-        if ((mr & AT91_RTT_RTPRES) != AT91_SLOW_CLOCK) {
-                mr = AT91_RTT_RTTRST | (AT91_SLOW_CLOCK & AT91_RTT_RTPRES);
+        if ((mr & AT91_RTT_RTPRES) != sclk_rate) {
+                mr = AT91_RTT_RTTRST | (sclk_rate & AT91_RTT_RTPRES);
                 gpbr_writel(rtc, 0);
         }
 
@@ -383,6 +451,9 @@ static int at91_rtc_remove(struct platform_device *pdev)
         /* disable all interrupts */
         rtt_writel(rtc, MR, mr & ~(AT91_RTT_ALMIEN | AT91_RTT_RTTINCIEN));
 
+        if (!IS_ERR(rtc->sclk))
+                clk_disable_unprepare(rtc->sclk);
+
         return 0;
 }
 
@@ -440,6 +511,14 @@ static int at91_rtc_resume(struct device *dev)
 
 static SIMPLE_DEV_PM_OPS(at91_rtc_pm_ops, at91_rtc_suspend, at91_rtc_resume);
 
+#ifdef CONFIG_OF
+static const struct of_device_id at91_rtc_dt_ids[] = {
+        { .compatible = "atmel,at91sam9260-rtt" },
+        { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, at91_rtc_dt_ids);
+#endif
+
 static struct platform_driver at91_rtc_driver = {
         .probe          = at91_rtc_probe,
         .remove         = at91_rtc_remove,
@@ -448,6 +527,7 @@ static struct platform_driver at91_rtc_driver = {
                 .name   = "rtc-at91sam9",
                 .owner  = THIS_MODULE,
                 .pm     = &at91_rtc_pm_ops,
+                .of_match_table = of_match_ptr(at91_rtc_dt_ids),
         },
 };