rtc: s3c: Make tick timer to be a selectable option.

s3c rtc driver has enabled timer tick default. However in some system,
it's not a mandatory option. So it modifies driver that tick timer can
be enabled selectively with a property, 's3c-rtc-tick-en', in DT.

Signed-off-by: Jonghwa Lee <jonghwa3.lee@samsung.com>
[k.kozlowski: rebased on 4.1]
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>

diff --git a/Documentation/devicetree/bindings/rtc/s3c-rtc.txt b/Documentation/devicetree/bindings/rtc/s3c-rtc.txt
index ab757b8..6bd598e 100644 (file)
--- a/Documentation/devicetree/bindings/rtc/s3c-rtc.txt
+++ b/Documentation/devicetree/bindings/rtc/s3c-rtc.txt
@@ -14,10 +14,14 @@ Required properties:
   is the rtc tick interrupt. The number of cells representing a interrupt
   depends on the parent interrupt controller.
 
+Optional Properties:
+- s3c-rtc-tick-en : flag for enabling tick timer
+
 Example:
 
        rtc@10070000 {
                compatible = "samsung,s3c6410-rtc";
                reg = <0x10070000 0x100>;
                interrupts = <44 0 45 0>;
+               s3c-rtc-tick-en;
        };

diff --git a/drivers/rtc/rtc-s3c.c b/drivers/rtc/rtc-s3c.c
index 463003d..c3f6dc5 100644 (file)
--- a/drivers/rtc/rtc-s3c.c
+++ b/drivers/rtc/rtc-s3c.c
@@ -56,10 +56,11 @@ struct s3c_rtc {
 struct s3c_rtc_data {
        int max_user_freq;
        bool needs_src_clk;
+       bool tick_en;
 
        void (*irq_handler) (struct s3c_rtc *info, int mask);
        void (*set_freq) (struct s3c_rtc *info, int freq);
-       void (*enable_tick) (struct s3c_rtc *info, struct seq_file *seq);
+       void (*enable_tick) (struct s3c_rtc *info, bool en);
        void (*select_tick_clk) (struct s3c_rtc *info);
        void (*save_tick_cnt) (struct s3c_rtc *info);
        void (*restore_tick_cnt) (struct s3c_rtc *info);
@@ -345,13 +346,8 @@ static int s3c_rtc_proc(struct device *dev, struct seq_file *seq)
 {
        struct s3c_rtc *info = dev_get_drvdata(dev);
 
-       s3c_rtc_enable_clk(info);
-
-       if (info->data->enable_tick)
-               info->data->enable_tick(info, seq);
-
-       s3c_rtc_disable_clk(info);
-
+       seq_printf(seq, "periodic_IRQ\t: %s\n",
+                       info->data->tick_en ? "yes" : "no");
        return 0;
 }
 
@@ -435,9 +431,15 @@ static const struct of_device_id s3c_rtc_dt_match[];
 static struct s3c_rtc_data *s3c_rtc_get_data(struct platform_device *pdev)
 {
        const struct of_device_id *match;
+       struct s3c_rtc_data *rtc_data;
 
        match = of_match_node(s3c_rtc_dt_match, pdev->dev.of_node);
-       return (struct s3c_rtc_data *)match->data;
+       rtc_data = (struct s3c_rtc_data *)match->data;
+
+       if (of_get_property(pdev->dev.of_node, "s3c-rtc-tick-en", NULL))
+               rtc_data->tick_en = true;
+
+       return rtc_data;
 }
 
 static int s3c_rtc_probe(struct platform_device *pdev)
@@ -540,17 +542,23 @@ static int s3c_rtc_probe(struct platform_device *pdev)
                goto err_nortc;
        }
 
-       ret = devm_request_irq(&pdev->dev, info->irq_tick, s3c_rtc_tickirq,
-                         0,  "s3c2410-rtc tick", info);
-       if (ret) {
-               dev_err(&pdev->dev, "IRQ%d error %d\n", info->irq_tick, ret);
-               goto err_nortc;
-       }
+       if (info->data->tick_en) {
+               ret = devm_request_irq(&pdev->dev, info->irq_tick,
+                               s3c_rtc_tickirq, 0,"s3c2410-rtc tick", info);
+               if (ret) {
+                       dev_err(&pdev->dev, "IRQ%d error %d\n",
+                                               info->irq_tick, ret);
+                       goto err_nortc;
+               }
+               info->data->enable_tick(info, true);
 
-       if (info->data->select_tick_clk)
-               info->data->select_tick_clk(info);
+               if (info->data->select_tick_clk)
+                       info->data->select_tick_clk(info);
 
-       s3c_rtc_setfreq(info, 1);
+               s3c_rtc_setfreq(info, info->rtc->max_user_freq);
+       } else {
+               info->data->enable_tick(info, false);
+       }
 
        s3c_rtc_disable_clk(info);
 
@@ -625,15 +633,25 @@ static void s3c6410_rtc_irq(struct s3c_rtc *info, int mask)
        writeb(mask, info->base + S3C2410_INTP);
 }
 
+static inline int s3c_rtc_get_tcnt(struct s3c_rtc *info, int freq)
+{
+       /*
+        * If requested frequency is larger than supported,
+        * it sets tick time count to minimum.
+        */
+       if (freq > info->data->max_user_freq)
+               return S3C_TCNT_MIN;
+
+       return info->data->max_user_freq / freq;
+}
+
 static void s3c2410_rtc_setfreq(struct s3c_rtc *info, int freq)
 {
        unsigned int tmp = 0;
        int val;
 
        tmp = readb(info->base + S3C2410_TICNT);
-       tmp &= S3C2410_TICNT_ENABLE;
-
-       val = (info->rtc->max_user_freq / freq) - 1;
+       val = s3c_rtc_get_tcnt(info, freq);
        tmp |= val;
 
        writel(tmp, info->base + S3C2410_TICNT);
@@ -645,9 +663,7 @@ static void s3c2416_rtc_setfreq(struct s3c_rtc *info, int freq)
        int val;
 
        tmp = readb(info->base + S3C2410_TICNT);
-       tmp &= S3C2410_TICNT_ENABLE;
-
-       val = (info->rtc->max_user_freq / freq) - 1;
+       val = s3c_rtc_get_tcnt(info, freq);
 
        tmp |= S3C2443_TICNT_PART(val);
        writel(S3C2443_TICNT1_PART(val), info->base + S3C2443_TICNT1);
@@ -665,7 +681,7 @@ static void s3c2443_rtc_setfreq(struct s3c_rtc *info, int freq)
        tmp = readb(info->base + S3C2410_TICNT);
        tmp &= S3C2410_TICNT_ENABLE;
 
-       val = (info->rtc->max_user_freq / freq) - 1;
+       val = s3c_rtc_get_tcnt(info, freq);
 
        tmp |= S3C2443_TICNT_PART(val);
        writel(S3C2443_TICNT1_PART(val), info->base + S3C2443_TICNT1);
@@ -677,18 +693,21 @@ static void s3c6410_rtc_setfreq(struct s3c_rtc *info, int freq)
 {
        int val;
 
-       val = (info->rtc->max_user_freq / freq) - 1;
+       val = s3c_rtc_get_tcnt(info, freq);
        writel(val, info->base + S3C2410_TICNT);
 }
 
-static void s3c24xx_rtc_enable_tick(struct s3c_rtc *info, struct seq_file *seq)
+static void s3c24xx_rtc_enable_tick(struct s3c_rtc *info, bool en)
 {
        unsigned int ticnt;
 
        ticnt = readb(info->base + S3C2410_TICNT);
-       ticnt &= S3C2410_TICNT_ENABLE;
-
-       seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt  ? "yes" : "no");
+       if (en)
+               ticnt |= S3C2410_TICNT_ENABLE;
+       else
+               ticnt &= ~S3C2410_TICNT_ENABLE;
+       writeb(ticnt, info->base + S3C2410_TICNT);
+       info->data->tick_en = en;
 }
 
 static void s3c2416_rtc_select_tick_clk(struct s3c_rtc *info)
@@ -700,14 +719,31 @@ static void s3c2416_rtc_select_tick_clk(struct s3c_rtc *info)
        writew(con, info->base + S3C2410_RTCCON);
 }
 
-static void s3c6410_rtc_enable_tick(struct s3c_rtc *info, struct seq_file *seq)
+static void s3c6410_rtc_enable_tick(struct s3c_rtc *info, bool en)
 {
        unsigned int ticnt;
 
        ticnt = readw(info->base + S3C2410_RTCCON);
-       ticnt &= S3C64XX_RTCCON_TICEN;
+       if (en)
+               ticnt |= S3C64XX_RTCCON_TICEN;
+       else
+               ticnt &= ~S3C64XX_RTCCON_TICEN;
+       writeb(ticnt, info->base + S3C2410_RTCCON);
+       info->data->tick_en = en;
+}
 
-       seq_printf(seq, "periodic_IRQ\t: %s\n", ticnt  ? "yes" : "no");
+static void s3c6410_rtc_select_tick_clk(struct s3c_rtc *info)
+{
+       unsigned int tmp;
+       int val;
+
+       tmp = readl(info->base + S3C2410_RTCCON);
+       tmp &= ~S3C64XX_CLKSEL_MASK;
+       val = (S3C_TICK_HZ_MAX / info->data->max_user_freq) - 1;
+       val <<= S3C64XX_CLKSEL_SHIFT;
+       val &= S3C64XX_CLKSEL_MASK;
+       tmp |= val;
+       writel(tmp, info->base + S3C2410_RTCCON);
 }
 
 static void s3c24xx_rtc_save_tick_cnt(struct s3c_rtc *info)
@@ -780,6 +816,7 @@ static struct s3c_rtc_data const s3c6410_rtc_data = {
        .irq_handler            = s3c6410_rtc_irq,
        .set_freq               = s3c6410_rtc_setfreq,
        .enable_tick            = s3c6410_rtc_enable_tick,
+       .select_tick_clk        = s3c6410_rtc_select_tick_clk,
        .save_tick_cnt          = s3c6410_rtc_save_tick_cnt,
        .restore_tick_cnt       = s3c6410_rtc_restore_tick_cnt,
        .enable                 = s3c24xx_rtc_enable,
@@ -792,6 +829,7 @@ static struct s3c_rtc_data const exynos3250_rtc_data = {
        .irq_handler            = s3c6410_rtc_irq,
        .set_freq               = s3c6410_rtc_setfreq,
        .enable_tick            = s3c6410_rtc_enable_tick,
+       .select_tick_clk        = s3c6410_rtc_select_tick_clk,
        .save_tick_cnt          = s3c6410_rtc_save_tick_cnt,
        .restore_tick_cnt       = s3c6410_rtc_restore_tick_cnt,
        .enable                 = s3c24xx_rtc_enable,

diff --git a/drivers/rtc/rtc-s3c.h b/drivers/rtc/rtc-s3c.h
index 004b61a..2a98c61 100644 (file)
--- a/drivers/rtc/rtc-s3c.h
+++ b/drivers/rtc/rtc-s3c.h
@@ -23,6 +23,13 @@
 #define S3C2410_RTCCON_CLKRST  (1 << 3)
 #define S3C2443_RTCCON_TICSEL  (1 << 4)
 #define S3C64XX_RTCCON_TICEN   (1 << 8)
+#define S3C64XX_CLKSEL_MASK    (0xf << S3C64XX_CLKSEL_SHIFT)
+#define S3C64XX_CLKSEL_SHIFT   (4)
+
+/* S3C rtc's Minimum tick count */
+#define S3C_TCNT_MIN           3
+/* S3C rtc's source clock rate is 32KHZ */
+#define S3C_TICK_HZ_MAX                32786
 
 #define S3C2410_TICNT          S3C2410_RTCREG(0x44)
 #define S3C2410_TICNT_ENABLE   (1 << 7)