rtc: rtc-sh: clock framework support.

This adds clock framework support to the rtc-sh driver. With this in
place, platforms can default to leaving the clock disabled rather than
placing it in the always enabled state.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

2 files changed, 50 insertions, 19 deletions

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index ffe34a12f44..4e9851fc174 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -573,7 +573,7 @@ config RTC_DRV_SA1100
 
 config RTC_DRV_SH
         tristate "SuperH On-Chip RTC"
-        depends on RTC_CLASS && SUPERH
+        depends on RTC_CLASS && SUPERH && HAVE_CLK
         help
           Say Y here to enable support for the on-chip RTC found in
           most SuperH processors.
diff --git a/drivers/rtc/rtc-sh.c b/drivers/rtc/rtc-sh.c
index 9b1ff12bf94..d7310adb715 100644
--- a/drivers/rtc/rtc-sh.c
+++ b/drivers/rtc/rtc-sh.c
@@ -1,7 +1,7 @@
 /*
  * SuperH On-Chip RTC Support
  *
- * Copyright (C) 2006, 2007, 2008  Paul Mundt
+ * Copyright (C) 2006 - 2009  Paul Mundt
  * Copyright (C) 2006  Jamie Lenehan
  * Copyright (C) 2008  Angelo Castello
  *
@@ -25,10 +25,11 @@
 #include <linux/spinlock.h>
 #include <linux/io.h>
 #include <linux/log2.h>
+#include <linux/clk.h>
 #include <asm/rtc.h>
 
 #define DRV_NAME        "sh-rtc"
-#define DRV_VERSION     "0.2.1"
+#define DRV_VERSION     "0.2.2"
 
 #define RTC_REG(r)      ((r) * rtc_reg_size)
 
@@ -87,16 +88,17 @@
 #define RCR2_START      0x01    /* Start bit               */
 
 struct sh_rtc {
-        void __iomem *regbase;
-        unsigned long regsize;
-        struct resource *res;
-        int alarm_irq;
-        int periodic_irq;
-        int carry_irq;
-        struct rtc_device *rtc_dev;
-        spinlock_t lock;
-        unsigned long capabilities;     /* See asm-sh/rtc.h for cap bits */
-        unsigned short periodic_freq;
+        void __iomem            *regbase;
+        unsigned long           regsize;
+        struct resource         *res;
+        int                     alarm_irq;
+        int                     periodic_irq;
+        int                     carry_irq;
+        struct clk              *clk;
+        struct rtc_device       *rtc_dev;
+        spinlock_t              lock;
+        unsigned long           capabilities;   /* See asm/rtc.h for cap bits */
+        unsigned short          periodic_freq;
 };
 
 static int __sh_rtc_interrupt(struct sh_rtc *rtc)
@@ -294,10 +296,10 @@ static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
 
         tmp = readb(rtc->regbase + RCR1);
 
-        if (!enable)
-                tmp &= ~RCR1_AIE;
-        else
+        if (enable)
                 tmp |= RCR1_AIE;
+        else
+                tmp &= ~RCR1_AIE;
 
         writeb(tmp, rtc->regbase + RCR1);
 
@@ -618,6 +620,7 @@ static int sh_rtc_irq_set_freq(struct device *dev, int freq)
 {
         if (!is_power_of_2(freq))
                 return -EINVAL;
+
         return sh_rtc_ioctl(dev, RTC_IRQP_SET, freq);
 }
 
@@ -637,7 +640,8 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
         struct sh_rtc *rtc;
         struct resource *res;
         struct rtc_time r;
-        int ret;
+        char clk_name[6];
+        int clk_id, ret;
 
         rtc = kzalloc(sizeof(struct sh_rtc), GFP_KERNEL);
         if (unlikely(!rtc))
@@ -652,6 +656,7 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
                 dev_err(&pdev->dev, "No IRQ resource\n");
                 goto err_badres;
         }
+
         rtc->periodic_irq = ret;
         rtc->carry_irq = platform_get_irq(pdev, 1);
         rtc->alarm_irq = platform_get_irq(pdev, 2);
@@ -663,7 +668,7 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
                 goto err_badres;
         }
 
-        rtc->regsize = res->end - res->start + 1;
+        rtc->regsize = resource_size(res);
 
         rtc->res = request_mem_region(res->start, rtc->regsize, pdev->name);
         if (unlikely(!rtc->res)) {
@@ -677,6 +682,26 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
                 goto err_badmap;
         }
 
+        clk_id = pdev->id;
+        /* With a single device, the clock id is still "rtc0" */
+        if (clk_id < 0)
+                clk_id = 0;
+
+        snprintf(clk_name, sizeof(clk_name), "rtc%d", clk_id);
+
+        rtc->clk = clk_get(&pdev->dev, clk_name);
+        if (IS_ERR(rtc->clk)) {
+                /*
+                 * No error handling for rtc->clk intentionally, not all
+                 * platforms will have a unique clock for the RTC, and
+                 * the clk API can handle the struct clk pointer being
+                 * NULL.
+                 */
+                rtc->clk = NULL;
+        }
+
+        clk_enable(rtc->clk);
+
         rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
                                            &sh_rtc_ops, THIS_MODULE);
         if (IS_ERR(rtc->rtc_dev)) {
@@ -759,6 +784,8 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
         return 0;
 
 err_unmap:
+        clk_disable(rtc->clk);
+        clk_put(rtc->clk);
         iounmap(rtc->regbase);
 err_badmap:
         release_resource(rtc->res);
@@ -780,6 +807,7 @@ static int __devexit sh_rtc_remove(struct platform_device *pdev)
         sh_rtc_setcie(&pdev->dev, 0);
 
         free_irq(rtc->periodic_irq, rtc);
+
         if (rtc->carry_irq > 0) {
                 free_irq(rtc->carry_irq, rtc);
                 free_irq(rtc->alarm_irq, rtc);
@@ -789,6 +817,9 @@ static int __devexit sh_rtc_remove(struct platform_device *pdev)
 
         iounmap(rtc->regbase);
 
+        clk_disable(rtc->clk);
+        clk_put(rtc->clk);
+
         platform_set_drvdata(pdev, NULL);
 
         kfree(rtc);
@@ -802,11 +833,11 @@ static void sh_rtc_set_irq_wake(struct device *dev, int enabled)
         struct sh_rtc *rtc = platform_get_drvdata(pdev);
 
         set_irq_wake(rtc->periodic_irq, enabled);
+
         if (rtc->carry_irq > 0) {
                 set_irq_wake(rtc->carry_irq, enabled);
                 set_irq_wake(rtc->alarm_irq, enabled);
         }
-
 }
 
 static int sh_rtc_suspend(struct device *dev)