rtc: at91sam9: make use of syscon/regmap to access GPBR registers

[firefly-linux-kernel-4.4.55.git] / drivers / rtc / rtc-at91sam9.c

diff --git a/drivers/rtc/rtc-at91sam9.c b/drivers/rtc/rtc-at91sam9.c
index d72c34d3f13003a2fc67ec8ff581f9766ecdd945..be9c28b9d057bd3ccc177b63f1ccb8f96de821e1 100644 (file)
--- a/drivers/rtc/rtc-at91sam9.c
+++ b/drivers/rtc/rtc-at91sam9.c
@@ -21,6 +21,8 @@
 #include <linux/slab.h>
 #include <linux/platform_data/atmel.h>
 #include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/regmap.h>
 
 /*
  * This driver uses two configurable hardware resources that live in the
@@ -72,7 +74,8 @@ struct sam9_rtc {
        void __iomem            *rtt;
        struct rtc_device       *rtcdev;
        u32                     imr;
-       void __iomem            *gpbr;
+       struct regmap           *gpbr;
+       unsigned int            gpbr_offset;
        int                     irq;
 };
 
@@ -81,10 +84,19 @@ struct sam9_rtc {
 #define rtt_writel(rtc, field, val) \
        writel((val), (rtc)->rtt + AT91_RTT_ ## field)
 
-#define gpbr_readl(rtc) \
-       readl((rtc)->gpbr)
-#define gpbr_writel(rtc, val) \
-       writel((val), (rtc)->gpbr)
+static inline unsigned int gpbr_readl(struct sam9_rtc *rtc)
+{
+       unsigned int val;
+
+       regmap_read(rtc->gpbr, rtc->gpbr_offset, &val);
+
+       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
@@ -301,6 +313,12 @@ 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
  */
@@ -334,10 +352,38 @@ static int at91_rtc_probe(struct platform_device *pdev)
        if (IS_ERR(rtc->rtt))
                return PTR_ERR(rtc->rtt);
 
-       r = platform_get_resource(pdev, IORESOURCE_MEM, 1);
-       rtc->gpbr = devm_ioremap_resource(&pdev->dev, r);
-       if (IS_ERR(rtc->gpbr))
-               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];
+       }
+
+       if (IS_ERR(rtc->gpbr)) {
+               dev_err(&pdev->dev, "failed to retrieve gpbr regmap, aborting.\n");
+               return -ENOMEM;
+       }
 
        mr = rtt_readl(rtc, MR);