rtc-ds1742: fix races around device registration
[safe/jmp/linux-2.6] / drivers / rtc / rtc-sh.c
index 9b1ff12..e95cc6f 100644 (file)
@@ -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
  *
 #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    "0.2.3"
 
 #define RTC_REG(r)     ((r) * rtc_reg_size)
 
 #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)
@@ -213,7 +215,7 @@ static irqreturn_t sh_rtc_shared(int irq, void *dev_id)
        return IRQ_RETVAL(ret);
 }
 
-static inline void sh_rtc_setpie(struct device *dev, unsigned int enable)
+static int sh_rtc_irq_set_state(struct device *dev, int enable)
 {
        struct sh_rtc *rtc = dev_get_drvdata(dev);
        unsigned int tmp;
@@ -223,17 +225,22 @@ static inline void sh_rtc_setpie(struct device *dev, unsigned int enable)
        tmp = readb(rtc->regbase + RCR2);
 
        if (enable) {
+               rtc->periodic_freq |= PF_KOU;
                tmp &= ~RCR2_PEF;       /* Clear PES bit */
                tmp |= (rtc->periodic_freq & ~PF_HP);   /* Set PES2-0 */
-       } else
+       } else {
+               rtc->periodic_freq &= ~PF_KOU;
                tmp &= ~(RCR2_PESMASK | RCR2_PEF);
+       }
 
        writeb(tmp, rtc->regbase + RCR2);
 
        spin_unlock_irq(&rtc->lock);
+
+       return 0;
 }
 
-static inline int sh_rtc_setfreq(struct device *dev, unsigned int freq)
+static int sh_rtc_irq_set_freq(struct device *dev, int freq)
 {
        struct sh_rtc *rtc = dev_get_drvdata(dev);
        int tmp, ret = 0;
@@ -276,10 +283,8 @@ static inline int sh_rtc_setfreq(struct device *dev, unsigned int freq)
                ret = -ENOTSUPP;
        }
 
-       if (ret == 0) {
+       if (ret == 0)
                rtc->periodic_freq |= tmp;
-               rtc->rtc_dev->irq_freq = freq;
-       }
 
        spin_unlock_irq(&rtc->lock);
        return ret;
@@ -294,10 +299,10 @@ 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);
 
@@ -344,10 +349,6 @@ static int sh_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
        unsigned int ret = 0;
 
        switch (cmd) {
-       case RTC_PIE_OFF:
-       case RTC_PIE_ON:
-               sh_rtc_setpie(dev, cmd == RTC_PIE_ON);
-               break;
        case RTC_AIE_OFF:
        case RTC_AIE_ON:
                sh_rtc_setaie(dev, cmd == RTC_AIE_ON);
@@ -360,13 +361,6 @@ static int sh_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
                rtc->periodic_freq |= PF_OXS;
                sh_rtc_setcie(dev, 1);
                break;
-       case RTC_IRQP_READ:
-               ret = put_user(rtc->rtc_dev->irq_freq,
-                              (unsigned long __user *)arg);
-               break;
-       case RTC_IRQP_SET:
-               ret = sh_rtc_setfreq(dev, arg);
-               break;
        default:
                ret = -ENOIOCTLCMD;
        }
@@ -600,27 +594,6 @@ static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
        return 0;
 }
 
-static int sh_rtc_irq_set_state(struct device *dev, int enabled)
-{
-       struct platform_device *pdev = to_platform_device(dev);
-       struct sh_rtc *rtc = platform_get_drvdata(pdev);
-
-       if (enabled) {
-               rtc->periodic_freq |= PF_KOU;
-               return sh_rtc_ioctl(dev, RTC_PIE_ON, 0);
-       } else {
-               rtc->periodic_freq &= ~PF_KOU;
-               return sh_rtc_ioctl(dev, RTC_PIE_OFF, 0);
-       }
-}
-
-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);
-}
-
 static struct rtc_class_ops sh_rtc_ops = {
        .ioctl          = sh_rtc_ioctl,
        .read_time      = sh_rtc_read_time,
@@ -632,12 +605,13 @@ static struct rtc_class_ops sh_rtc_ops = {
        .proc           = sh_rtc_proc,
 };
 
-static int __devinit sh_rtc_probe(struct platform_device *pdev)
+static int __init 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 +626,7 @@ 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 +638,7 @@ 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)) {
@@ -677,13 +652,26 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
                goto err_badmap;
        }
 
-       rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
-                                          &sh_rtc_ops, THIS_MODULE);
-       if (IS_ERR(rtc->rtc_dev)) {
-               ret = PTR_ERR(rtc->rtc_dev);
-               goto err_unmap;
+       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->capabilities = RTC_DEF_CAPABILITIES;
        if (pdev->dev.platform_data) {
                struct sh_rtc_platform_info *pinfo = pdev->dev.platform_data;
@@ -695,10 +683,6 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
                rtc->capabilities |= pinfo->capabilities;
        }
 
-       rtc->rtc_dev->max_user_freq = 256;
-
-       platform_set_drvdata(pdev, rtc);
-
        if (rtc->carry_irq <= 0) {
                /* register shared periodic/carry/alarm irq */
                ret = request_irq(rtc->periodic_irq, sh_rtc_shared,
@@ -742,13 +726,26 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
                }
        }
 
+       platform_set_drvdata(pdev, rtc);
+
        /* everything disabled by default */
-       rtc->periodic_freq = 0;
-       rtc->rtc_dev->irq_freq = 0;
-       sh_rtc_setpie(&pdev->dev, 0);
+       sh_rtc_irq_set_freq(&pdev->dev, 0);
+       sh_rtc_irq_set_state(&pdev->dev, 0);
        sh_rtc_setaie(&pdev->dev, 0);
        sh_rtc_setcie(&pdev->dev, 0);
 
+       rtc->rtc_dev = rtc_device_register("sh", &pdev->dev,
+                                          &sh_rtc_ops, THIS_MODULE);
+       if (IS_ERR(rtc->rtc_dev)) {
+               ret = PTR_ERR(rtc->rtc_dev);
+               free_irq(rtc->periodic_irq, rtc);
+               free_irq(rtc->carry_irq, rtc);
+               free_irq(rtc->alarm_irq, rtc);
+               goto err_unmap;
+       }
+
+       rtc->rtc_dev->max_user_freq = 256;
+
        /* reset rtc to epoch 0 if time is invalid */
        if (rtc_read_time(rtc->rtc_dev, &r) < 0) {
                rtc_time_to_tm(0, &r);
@@ -759,6 +756,8 @@ 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);
@@ -768,26 +767,28 @@ err_badres:
        return ret;
 }
 
-static int __devexit sh_rtc_remove(struct platform_device *pdev)
+static int __exit sh_rtc_remove(struct platform_device *pdev)
 {
        struct sh_rtc *rtc = platform_get_drvdata(pdev);
 
-       if (likely(rtc->rtc_dev))
-               rtc_device_unregister(rtc->rtc_dev);
+       rtc_device_unregister(rtc->rtc_dev);
+       sh_rtc_irq_set_state(&pdev->dev, 0);
 
-       sh_rtc_setpie(&pdev->dev, 0);
        sh_rtc_setaie(&pdev->dev, 0);
        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);
        }
 
+       iounmap(rtc->regbase);
        release_resource(rtc->res);
 
-       iounmap(rtc->regbase);
+       clk_disable(rtc->clk);
+       clk_put(rtc->clk);
 
        platform_set_drvdata(pdev, NULL);
 
@@ -802,11 +803,11 @@ 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)
@@ -825,7 +826,7 @@ static int sh_rtc_resume(struct device *dev)
        return 0;
 }
 
-static struct dev_pm_ops sh_rtc_dev_pm_ops = {
+static const struct dev_pm_ops sh_rtc_dev_pm_ops = {
        .suspend = sh_rtc_suspend,
        .resume = sh_rtc_resume,
 };
@@ -836,13 +837,12 @@ static struct platform_driver sh_rtc_platform_driver = {
                .owner  = THIS_MODULE,
                .pm     = &sh_rtc_dev_pm_ops,
        },
-       .probe          = sh_rtc_probe,
-       .remove         = __devexit_p(sh_rtc_remove),
+       .remove         = __exit_p(sh_rtc_remove),
 };
 
 static int __init sh_rtc_init(void)
 {
-       return platform_driver_register(&sh_rtc_platform_driver);
+       return platform_driver_probe(&sh_rtc_platform_driver, sh_rtc_probe);
 }
 
 static void __exit sh_rtc_exit(void)