rtc: rtc-sh: Add support for periodic IRQs.

This adds support for periodic IRQs to the rtc-sh driver.
RTC_IRQP_READ/RTC_IRQP_SET are added, with a number of other fixes and
reordering across the rest of the code.

Signed-off-by: Angelo Castello <angelo.castello@st.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 187 insertions, 109 deletions

diff --git a/drivers/rtc/rtc-sh.c b/drivers/rtc/rtc-sh.c
index 9e9caa5d7f5f..c594b34c6767 100644
--- a/drivers/rtc/rtc-sh.c
+++ b/drivers/rtc/rtc-sh.c
@@ -1,8 +1,9 @@
 /*
  * SuperH On-Chip RTC Support
  *
- * Copyright (C) 2006, 2007  Paul Mundt
+ * Copyright (C) 2006, 2007, 2008  Paul Mundt
  * Copyright (C) 2006  Jamie Lenehan
+ * Copyright (C) 2008  Angelo Castello
  *
  * Based on the old arch/sh/kernel/cpu/rtc.c by:
  *
@@ -26,7 +27,7 @@
 #include <asm/rtc.h>
 
 #define DRV_NAME        "sh-rtc"
-#define DRV_VERSION     "0.1.6"
+#define DRV_VERSION     "0.2.0"
 
 #define RTC_REG(r)      ((r) * rtc_reg_size)
 
@@ -63,6 +64,13 @@
 /* ALARM Bits - or with BCD encoded value */
 #define AR_ENB          0x80    /* Enable for alarm cmp   */
 
+/* Period Bits */
+#define PF_HP           0x100   /* Enable Half Period to support 8,32,128Hz */
+#define PF_COUNT        0x200   /* Half periodic counter */
+#define PF_OXS          0x400   /* Periodic One x Second */
+#define PF_KOU          0x800   /* Kernel or User periodic request 1=kernel */
+#define PF_MASK         0xf00
+
 /* RCR1 Bits */
 #define RCR1_CF         0x80    /* Carry Flag             */
 #define RCR1_CIE        0x10    /* Carry Interrupt Enable */
@@ -84,33 +92,24 @@ struct sh_rtc {
         unsigned int alarm_irq, periodic_irq, carry_irq;
         struct rtc_device *rtc_dev;
         spinlock_t lock;
-        int rearm_aie;
         unsigned long capabilities;     /* See asm-sh/rtc.h for cap bits */
+        unsigned short periodic_freq;
 };
 
 static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
 {
-        struct platform_device *pdev = to_platform_device(dev_id);
-        struct sh_rtc *rtc = platform_get_drvdata(pdev);
-        unsigned int tmp, events = 0;
+        struct sh_rtc *rtc = dev_id;
+        unsigned int tmp;
 
         spin_lock(&rtc->lock);
 
         tmp = readb(rtc->regbase + RCR1);
         tmp &= ~RCR1_CF;
-
-        if (rtc->rearm_aie) {
-                if (tmp & RCR1_AF)
-                        tmp &= ~RCR1_AF;        /* try to clear AF again */
-                else {
-                        tmp |= RCR1_AIE;        /* AF has cleared, rearm IRQ */
-                        rtc->rearm_aie = 0;
-                }
-        }
-
         writeb(tmp, rtc->regbase + RCR1);
 
-        rtc_update_irq(rtc->rtc_dev, 1, events);
+        /* Users have requested One x Second IRQ */
+        if (rtc->periodic_freq & PF_OXS)
+                rtc_update_irq(rtc->rtc_dev, 1, RTC_UF | RTC_IRQF);
 
         spin_unlock(&rtc->lock);
 
@@ -119,47 +118,48 @@ static irqreturn_t sh_rtc_interrupt(int irq, void *dev_id)
 
 static irqreturn_t sh_rtc_alarm(int irq, void *dev_id)
 {
-        struct platform_device *pdev = to_platform_device(dev_id);
-        struct sh_rtc *rtc = platform_get_drvdata(pdev);
-        unsigned int tmp, events = 0;
+        struct sh_rtc *rtc = dev_id;
+        unsigned int tmp;
 
         spin_lock(&rtc->lock);
 
         tmp = readb(rtc->regbase + RCR1);
-
-        /*
-         * If AF is set then the alarm has triggered. If we clear AF while
-         * the alarm time still matches the RTC time then AF will
-         * immediately be set again, and if AIE is enabled then the alarm
-         * interrupt will immediately be retrigger. So we clear AIE here
-         * and use rtc->rearm_aie so that the carry interrupt will keep
-         * trying to clear AF and once it stays cleared it'll re-enable
-         * AIE.
-         */
-        if (tmp & RCR1_AF) {
-                events |= RTC_AF | RTC_IRQF;
-
-                tmp &= ~(RCR1_AF|RCR1_AIE);
-
+        tmp &= ~(RCR1_AF | RCR1_AIE);
                 writeb(tmp, rtc->regbase + RCR1);
 
-                rtc->rearm_aie = 1;
-
-                rtc_update_irq(rtc->rtc_dev, 1, events);
-        }
+        rtc_update_irq(rtc->rtc_dev, 1, RTC_AF | RTC_IRQF);
 
         spin_unlock(&rtc->lock);
+
         return IRQ_HANDLED;
 }
 
 static irqreturn_t sh_rtc_periodic(int irq, void *dev_id)
 {
-        struct platform_device *pdev = to_platform_device(dev_id);
-        struct sh_rtc *rtc = platform_get_drvdata(pdev);
+        struct sh_rtc *rtc = dev_id;
+        struct rtc_device *rtc_dev = rtc->rtc_dev;
+        unsigned int tmp;
 
         spin_lock(&rtc->lock);
 
-        rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
+        tmp = readb(rtc->regbase + RCR2);
+        tmp &= ~RCR2_PEF;
+        writeb(tmp, rtc->regbase + RCR2);
+
+        /* Half period enabled than one skipped and the next notified */
+        if ((rtc->periodic_freq & PF_HP) && (rtc->periodic_freq & PF_COUNT))
+                rtc->periodic_freq &= ~PF_COUNT;
+        else {
+                if (rtc->periodic_freq & PF_HP)
+                        rtc->periodic_freq |= PF_COUNT;
+                if (rtc->periodic_freq & PF_KOU) {
+                        spin_lock(&rtc_dev->irq_task_lock);
+                        if (rtc_dev->irq_task)
+                                rtc_dev->irq_task->func(rtc_dev->irq_task->private_data);
+                        spin_unlock(&rtc_dev->irq_task_lock);
+                } else
+                        rtc_update_irq(rtc->rtc_dev, 1, RTC_PF | RTC_IRQF);
+        }
 
         spin_unlock(&rtc->lock);
 
@@ -176,8 +176,8 @@ static inline void sh_rtc_setpie(struct device *dev, unsigned int enable)
         tmp = readb(rtc->regbase + RCR2);
 
         if (enable) {
-                tmp &= ~RCR2_PESMASK;
-                tmp |= RCR2_PEF | (2 << 4);
+                tmp &= ~RCR2_PEF;       /* Clear PES bit */
+                tmp |= (rtc->periodic_freq & ~PF_HP);   /* Set PES2-0 */
         } else
                 tmp &= ~(RCR2_PESMASK | RCR2_PEF);
 
@@ -186,82 +186,81 @@ static inline void sh_rtc_setpie(struct device *dev, unsigned int enable)
         spin_unlock_irq(&rtc->lock);
 }
 
-static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
+static inline int sh_rtc_setfreq(struct device *dev, unsigned int freq)
 {
         struct sh_rtc *rtc = dev_get_drvdata(dev);
-        unsigned int tmp;
+        int tmp, ret = 0;
 
         spin_lock_irq(&rtc->lock);
+        tmp = rtc->periodic_freq & PF_MASK;
 
-        tmp = readb(rtc->regbase + RCR1);
-
-        if (!enable) {
-                tmp &= ~RCR1_AIE;
-                rtc->rearm_aie = 0;
-        } else if (rtc->rearm_aie == 0)
-                tmp |= RCR1_AIE;
+        switch (freq) {
+        case 0:
+                rtc->periodic_freq = 0x00;
+                break;
+        case 1:
+                rtc->periodic_freq = 0x60;
+                break;
+        case 2:
+                rtc->periodic_freq = 0x50;
+                break;
+        case 4:
+                rtc->periodic_freq = 0x40;
+                break;
+        case 8:
+                rtc->periodic_freq = 0x30 | PF_HP;
+                break;
+        case 16:
+                rtc->periodic_freq = 0x30;
+                break;
+        case 32:
+                rtc->periodic_freq = 0x20 | PF_HP;
+                break;
+        case 64:
+                rtc->periodic_freq = 0x20;
+                break;
+        case 128:
+                rtc->periodic_freq = 0x10 | PF_HP;
+                break;
+        case 256:
+                rtc->periodic_freq = 0x10;
+                break;
+        default:
+                ret = -ENOTSUPP;
+        }
 
-        writeb(tmp, rtc->regbase + RCR1);
+        if (ret == 0) {
+                rtc->periodic_freq |= tmp;
+                rtc->rtc_dev->irq_freq = freq;
+        }
 
         spin_unlock_irq(&rtc->lock);
+        return ret;
 }
 
-static int sh_rtc_open(struct device *dev)
+static inline void sh_rtc_setaie(struct device *dev, unsigned int enable)
 {
         struct sh_rtc *rtc = dev_get_drvdata(dev);
         unsigned int tmp;
-        int ret;
-
-        tmp = readb(rtc->regbase + RCR1);
-        tmp &= ~RCR1_CF;
-        tmp |= RCR1_CIE;
-        writeb(tmp, rtc->regbase + RCR1);
 
-        ret = request_irq(rtc->periodic_irq, sh_rtc_periodic, IRQF_DISABLED,
-                          "sh-rtc period", dev);
-        if (unlikely(ret)) {
-                dev_err(dev, "request period IRQ failed with %d, IRQ %d\n",
-                        ret, rtc->periodic_irq);
-                return ret;
-        }
-
-        ret = request_irq(rtc->carry_irq, sh_rtc_interrupt, IRQF_DISABLED,
-                          "sh-rtc carry", dev);
-        if (unlikely(ret)) {
-                dev_err(dev, "request carry IRQ failed with %d, IRQ %d\n",
-                        ret, rtc->carry_irq);
-                free_irq(rtc->periodic_irq, dev);
-                goto err_bad_carry;
-        }
+        spin_lock_irq(&rtc->lock);
 
-        ret = request_irq(rtc->alarm_irq, sh_rtc_alarm, IRQF_DISABLED,
-                          "sh-rtc alarm", dev);
-        if (unlikely(ret)) {
-                dev_err(dev, "request alarm IRQ failed with %d, IRQ %d\n",
-                        ret, rtc->alarm_irq);
-                goto err_bad_alarm;
-        }
+        tmp = readb(rtc->regbase + RCR1);
 
-        return 0;
+        if (!enable)
+                tmp &= ~RCR1_AIE;
+        else
+                tmp |= RCR1_AIE;
 
-err_bad_alarm:
-        free_irq(rtc->carry_irq, dev);
-err_bad_carry:
-        free_irq(rtc->periodic_irq, dev);
+        writeb(tmp, rtc->regbase + RCR1);
 
-        return ret;
+        spin_unlock_irq(&rtc->lock);
 }
 
 static void sh_rtc_release(struct device *dev)
 {
-        struct sh_rtc *rtc = dev_get_drvdata(dev);
-
         sh_rtc_setpie(dev, 0);
         sh_rtc_setaie(dev, 0);
-
-        free_irq(rtc->periodic_irq, dev);
-        free_irq(rtc->carry_irq, dev);
-        free_irq(rtc->alarm_irq, dev);
 }
 
 static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
@@ -270,31 +269,44 @@ static int sh_rtc_proc(struct device *dev, struct seq_file *seq)
         unsigned int tmp;
 
         tmp = readb(rtc->regbase + RCR1);
-        seq_printf(seq, "carry_IRQ\t: %s\n",
-                   (tmp & RCR1_CIE) ? "yes" : "no");
+        seq_printf(seq, "carry_IRQ\t: %s\n", (tmp & RCR1_CIE) ? "yes" : "no");
 
         tmp = readb(rtc->regbase + RCR2);
         seq_printf(seq, "periodic_IRQ\t: %s\n",
-                   (tmp & RCR2_PEF) ? "yes" : "no");
+                   (tmp & RCR2_PESMASK) ? "yes" : "no");
 
         return 0;
 }
 
 static int sh_rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
 {
-        unsigned int ret = -ENOIOCTLCMD;
+        struct sh_rtc *rtc = dev_get_drvdata(dev);
+        unsigned int ret = 0;
 
         switch (cmd) {
         case RTC_PIE_OFF:
         case RTC_PIE_ON:
                 sh_rtc_setpie(dev, cmd == RTC_PIE_ON);
-                ret = 0;
                 break;
         case RTC_AIE_OFF:
         case RTC_AIE_ON:
                 sh_rtc_setaie(dev, cmd == RTC_AIE_ON);
-                ret = 0;
                 break;
+        case RTC_UIE_OFF:
+                rtc->periodic_freq &= ~PF_OXS;
+                break;
+        case RTC_UIE_ON:
+                rtc->periodic_freq |= PF_OXS;
+                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;
         }
 
         return ret;
@@ -421,7 +433,7 @@ static int sh_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 {
         struct platform_device *pdev = to_platform_device(dev);
         struct sh_rtc *rtc = platform_get_drvdata(pdev);
-        struct rtc_time* tm = &wkalrm->time;
+        struct rtc_time *tm = &wkalrm->time;
 
         spin_lock_irq(&rtc->lock);
 
@@ -452,7 +464,7 @@ static inline void sh_rtc_write_alarm_value(struct sh_rtc *rtc,
                 writeb(BIN2BCD(value) | AR_ENB,  rtc->regbase + reg_off);
 }
 
-static int sh_rtc_check_alarm(struct rtc_time* tm)
+static int sh_rtc_check_alarm(struct rtc_time *tm)
 {
         /*
          * The original rtc says anything > 0xc0 is "don't care" or "match
@@ -503,11 +515,9 @@ static int sh_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *wkalrm)
 
         /* disable alarm interrupt and clear the alarm flag */
         rcr1 = readb(rtc->regbase + RCR1);
-        rcr1 &= ~(RCR1_AF|RCR1_AIE);
+        rcr1 &= ~(RCR1_AF | RCR1_AIE);
         writeb(rcr1, rtc->regbase + RCR1);
 
-        rtc->rearm_aie = 0;
-
         /* set alarm time */
         sh_rtc_write_alarm_value(rtc, tm->tm_sec,  RSECAR);
         sh_rtc_write_alarm_value(rtc, tm->tm_min,  RMINAR);
@@ -529,14 +539,34 @@ 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)
+{
+        return sh_rtc_ioctl(dev, RTC_IRQP_SET, freq);
+}
+
 static struct rtc_class_ops sh_rtc_ops = {
-        .open           = sh_rtc_open,
         .release        = sh_rtc_release,
         .ioctl          = sh_rtc_ioctl,
         .read_time      = sh_rtc_read_time,
         .set_time       = sh_rtc_set_time,
         .read_alarm     = sh_rtc_read_alarm,
         .set_alarm      = sh_rtc_set_alarm,
+        .irq_set_state  = sh_rtc_irq_set_state,
+        .irq_set_freq   = sh_rtc_irq_set_freq,
         .proc           = sh_rtc_proc,
 };
 
@@ -544,6 +574,7 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
 {
         struct sh_rtc *rtc;
         struct resource *res;
+        unsigned int tmp;
         int ret = -ENOENT;
 
         rtc = kzalloc(sizeof(struct sh_rtc), GFP_KERNEL);
@@ -552,6 +583,7 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
 
         spin_lock_init(&rtc->lock);
 
+        /* get periodic/carry/alarm irqs */
         rtc->periodic_irq = platform_get_irq(pdev, 0);
         if (unlikely(rtc->periodic_irq < 0)) {
                 dev_err(&pdev->dev, "No IRQ for period\n");
@@ -608,8 +640,48 @@ static int __devinit sh_rtc_probe(struct platform_device *pdev)
                 rtc->capabilities |= pinfo->capabilities;
         }
 
+        rtc->rtc_dev->max_user_freq = 256;
+        rtc->rtc_dev->irq_freq = 1;
+        rtc->periodic_freq = 0x60;
+
         platform_set_drvdata(pdev, rtc);
 
+        /* register periodic/carry/alarm irqs */
+        ret = request_irq(rtc->periodic_irq, sh_rtc_periodic, IRQF_DISABLED,
+                          "sh-rtc period", rtc);
+        if (unlikely(ret)) {
+                dev_err(&pdev->dev,
+                        "request period IRQ failed with %d, IRQ %d\n", ret,
+                        rtc->periodic_irq);
+                goto err_badmap;
+        }
+
+        ret = request_irq(rtc->carry_irq, sh_rtc_interrupt, IRQF_DISABLED,
+                          "sh-rtc carry", rtc);
+        if (unlikely(ret)) {
+                dev_err(&pdev->dev,
+                        "request carry IRQ failed with %d, IRQ %d\n", ret,
+                        rtc->carry_irq);
+                free_irq(rtc->periodic_irq, rtc);
+                goto err_badmap;
+        }
+
+        ret = request_irq(rtc->alarm_irq, sh_rtc_alarm, IRQF_DISABLED,
+                          "sh-rtc alarm", rtc);
+        if (unlikely(ret)) {
+                dev_err(&pdev->dev,
+                        "request alarm IRQ failed with %d, IRQ %d\n", ret,
+                        rtc->alarm_irq);
+                free_irq(rtc->carry_irq, rtc);
+                free_irq(rtc->periodic_irq, rtc);
+                goto err_badmap;
+        }
+
+        tmp = readb(rtc->regbase + RCR1);
+        tmp &= ~RCR1_CF;
+        tmp |= RCR1_CIE;
+        writeb(tmp, rtc->regbase + RCR1);
+
         return 0;
 
 err_badmap:
@@ -630,6 +702,10 @@ static int __devexit sh_rtc_remove(struct platform_device *pdev)
         sh_rtc_setpie(&pdev->dev, 0);
         sh_rtc_setaie(&pdev->dev, 0);
 
+        free_irq(rtc->carry_irq, rtc);
+        free_irq(rtc->periodic_irq, rtc);
+        free_irq(rtc->alarm_irq, rtc);
+
         release_resource(rtc->res);
 
         platform_set_drvdata(pdev, NULL);
@@ -662,6 +738,8 @@ module_exit(sh_rtc_exit);
 
 MODULE_DESCRIPTION("SuperH on-chip RTC driver");
 MODULE_VERSION(DRV_VERSION);
-MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, Jamie Lenehan <lenehan@twibble.org>");
+MODULE_AUTHOR("Paul Mundt <lethal@linux-sh.org>, "
+              "Jamie Lenehan <lenehan@twibble.org>, "
+              "Angelo Castello <angelo.castello@st.com>");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS("platform:" DRV_NAME);