sparc32: use RTC subsystem

Use rtc subsystem for sparc32 architecture.
Actually, only one driver is needed: m48t59
as it supports the most common clocks on sparc32
machines: m48t08 and m48t02.

[ Add proper RTC layer calls to set_rtc_mmss() -DaveM ]

Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 60 insertions, 157 deletions

diff --git a/arch/sparc/kernel/time.c b/arch/sparc/kernel/time.c
index f0a2874b04e9..698c45059fa5 100644
--- a/arch/sparc/kernel/time.c
+++ b/arch/sparc/kernel/time.c
@@ -23,6 +23,8 @@
 #include <linux/mm.h>
 #include <linux/interrupt.h>
 #include <linux/time.h>
+#include <linux/rtc.h>
+#include <linux/rtc/m48t59.h>
 #include <linux/timex.h>
 #include <linux/init.h>
 #include <linux/pci.h>
@@ -30,10 +32,10 @@
 #include <linux/profile.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
+#include <linux/platform_device.h>
 
 #include <asm/oplib.h>
 #include <asm/timer.h>
-#include <asm/mostek.h>
 #include <asm/system.h>
 #include <asm/irq.h>
 #include <asm/io.h>
@@ -46,10 +48,6 @@
 #include "irq.h"
 
 DEFINE_SPINLOCK(rtc_lock);
-static enum sparc_clock_type sp_clock_typ;
-DEFINE_SPINLOCK(mostek_lock);
-void __iomem *mstk48t02_regs = NULL;
-static struct mostek48t08 __iomem *mstk48t08_regs = NULL;
 static int set_rtc_mmss(unsigned long);
 static int sbus_do_settimeofday(struct timespec *tv);
 
@@ -118,107 +116,55 @@ static irqreturn_t timer_interrupt(int dummy, void *dev_id)
         return IRQ_HANDLED;
 }
 
-/* Kick start a stopped clock (procedure from the Sun NVRAM/hostid FAQ). */
-static void __devinit kick_start_clock(void)
+static unsigned char mostek_read_byte(struct device *dev, u32 ofs)
 {
-        struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
-        unsigned char sec;
-        int i, count;
-
-        prom_printf("CLOCK: Clock was stopped. Kick start ");
-
-        spin_lock_irq(&mostek_lock);
-
-        /* Turn on the kick start bit to start the oscillator. */
-        regs->creg |= MSTK_CREG_WRITE;
-        regs->sec &= ~MSTK_STOP;
-        regs->hour |= MSTK_KICK_START;
-        regs->creg &= ~MSTK_CREG_WRITE;
-
-        spin_unlock_irq(&mostek_lock);
-
-        /* Delay to allow the clock oscillator to start. */
-        sec = MSTK_REG_SEC(regs);
-        for (i = 0; i < 3; i++) {
-                while (sec == MSTK_REG_SEC(regs))
-                        for (count = 0; count < 100000; count++)
-                                /* nothing */ ;
-                prom_printf(".");
-                sec = regs->sec;
+        struct platform_device *pdev = to_platform_device(dev);
+        struct m48t59_plat_data *pdata = pdev->dev.platform_data;
+        void __iomem *regs = pdata->ioaddr;
+        unsigned char val = readb(regs + ofs);
+
+        /* the year 0 is 1968 */
+        if (ofs == pdata->offset + M48T59_YEAR) {
+                val += 0x68;
+                if ((val & 0xf) > 9)
+                        val += 6;
         }
-        prom_printf("\n");
-
-        spin_lock_irq(&mostek_lock);
-
-        /* Turn off kick start and set a "valid" time and date. */
-        regs->creg |= MSTK_CREG_WRITE;
-        regs->hour &= ~MSTK_KICK_START;
-        MSTK_SET_REG_SEC(regs,0);
-        MSTK_SET_REG_MIN(regs,0);
-        MSTK_SET_REG_HOUR(regs,0);
-        MSTK_SET_REG_DOW(regs,5);
-        MSTK_SET_REG_DOM(regs,1);
-        MSTK_SET_REG_MONTH(regs,8);
-        MSTK_SET_REG_YEAR(regs,1996 - MSTK_YEAR_ZERO);
-        regs->creg &= ~MSTK_CREG_WRITE;
-
-        spin_unlock_irq(&mostek_lock);
-
-        /* Ensure the kick start bit is off. If it isn't, turn it off. */
-        while (regs->hour & MSTK_KICK_START) {
-                prom_printf("CLOCK: Kick start still on!\n");
-
-                spin_lock_irq(&mostek_lock);
-                regs->creg |= MSTK_CREG_WRITE;
-                regs->hour &= ~MSTK_KICK_START;
-                regs->creg &= ~MSTK_CREG_WRITE;
-                spin_unlock_irq(&mostek_lock);
-        }
-
-        prom_printf("CLOCK: Kick start procedure successful.\n");
+        return val;
 }
 
-/* Return nonzero if the clock chip battery is low. */
-static inline int has_low_battery(void)
+static void mostek_write_byte(struct device *dev, u32 ofs, u8 val)
 {
-        struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
-        unsigned char data1, data2;
-
-        spin_lock_irq(&mostek_lock);
-        data1 = regs->eeprom[0];        /* Read some data. */
-        regs->eeprom[0] = ~data1;       /* Write back the complement. */
-        data2 = regs->eeprom[0];        /* Read back the complement. */
-        regs->eeprom[0] = data1;        /* Restore the original value. */
-        spin_unlock_irq(&mostek_lock);
-
-        return (data1 == data2);        /* Was the write blocked? */
+        struct platform_device *pdev = to_platform_device(dev);
+        struct m48t59_plat_data *pdata = pdev->dev.platform_data;
+        void __iomem *regs = pdata->ioaddr;
+
+        if (ofs == pdata->offset + M48T59_YEAR) {
+                if (val < 0x68)
+                        val += 0x32;
+                else
+                        val -= 0x68;
+                if ((val & 0xf) > 9)
+                        val += 6;
+                if ((val & 0xf0) > 0x9A)
+                        val += 0x60;
+        }
+        writeb(val, regs + ofs);
 }
 
-static void __devinit mostek_set_system_time(void)
-{
-        unsigned int year, mon, day, hour, min, sec;
-        struct mostek48t02 *mregs;
-
-        mregs = (struct mostek48t02 *)mstk48t02_regs;
-        if(!mregs) {
-                prom_printf("Something wrong, clock regs not mapped yet.\n");
-                prom_halt();
-        }               
-        spin_lock_irq(&mostek_lock);
-        mregs->creg |= MSTK_CREG_READ;
-        sec = MSTK_REG_SEC(mregs);
-        min = MSTK_REG_MIN(mregs);
-        hour = MSTK_REG_HOUR(mregs);
-        day = MSTK_REG_DOM(mregs);
-        mon = MSTK_REG_MONTH(mregs);
-        year = MSTK_CVT_YEAR( MSTK_REG_YEAR(mregs) );
-        xtime.tv_sec = mktime(year, mon, day, hour, min, sec);
-        xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ);
-        set_normalized_timespec(&wall_to_monotonic,
-                                -xtime.tv_sec, -xtime.tv_nsec);
-        mregs->creg &= ~MSTK_CREG_READ;
-        spin_unlock_irq(&mostek_lock);
-}
+static struct m48t59_plat_data m48t59_data = {
+        .read_byte = mostek_read_byte,
+        .write_byte = mostek_write_byte,
+};
+
+/* resource is set at runtime */
+static struct platform_device m48t59_rtc = {
+        .name           = "rtc-m48t59",
+        .id             = 0,
+        .num_resources  = 1,
+        .dev    = {
+                .platform_data = &m48t59_data,
+        },
+};
 
 static int __devinit clock_probe(struct of_device *op, const struct of_device_id *match)
 {
@@ -228,33 +174,21 @@ static int __devinit clock_probe(struct of_device *op, const struct of_device_id
         if (!model)
                 return -ENODEV;
 
+        m48t59_rtc.resource = &op->resource[0];
         if (!strcmp(model, "mk48t02")) {
-                sp_clock_typ = MSTK48T02;
-
                 /* Map the clock register io area read-only */
-                mstk48t02_regs = of_ioremap(&op->resource[0], 0,
-                                            sizeof(struct mostek48t02),
-                                            "mk48t02");
-                mstk48t08_regs = NULL;  /* To catch weirdness */
+                m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
+                                                2048, "rtc-m48t59");
+                m48t59_data.type = M48T59RTC_TYPE_M48T02;
         } else if (!strcmp(model, "mk48t08")) {
-                sp_clock_typ = MSTK48T08;
-                mstk48t08_regs = of_ioremap(&op->resource[0], 0,
-                                            sizeof(struct mostek48t08),
-                                            "mk48t08");
-
-                mstk48t02_regs = &mstk48t08_regs->regs;
+                m48t59_data.ioaddr = of_ioremap(&op->resource[0], 0,
+                                                8192, "rtc-m48t59");
+                m48t59_data.type = M48T59RTC_TYPE_M48T08;
         } else
                 return -ENODEV;
 
-        /* Report a low battery voltage condition. */
-        if (has_low_battery())
-                printk(KERN_CRIT "NVRAM: Low battery voltage!\n");
-
-        /* Kick start the clock if it is completely stopped. */
-        if (mostek_read(mstk48t02_regs + MOSTEK_SEC) & MSTK_STOP)
-                kick_start_clock();
-
-        mostek_set_system_time();
+        if (platform_device_register(&m48t59_rtc) < 0)
+                printk(KERN_ERR "Registering RTC device failed\n");
 
         return 0;
 }
@@ -270,7 +204,7 @@ static struct of_platform_driver clock_driver = {
         .match_table    = clock_match,
         .probe          = clock_probe,
         .driver         = {
-                .name   = "clock",
+                .name   = "rtc",
         },
 };
 
@@ -400,43 +334,12 @@ static int sbus_do_settimeofday(struct timespec *tv)
         return 0;
 }
 
-/*
- * BUG: This routine does not handle hour overflow properly; it just
- *      sets the minutes. Usually you won't notice until after reboot!
- */
-static int set_rtc_mmss(unsigned long nowtime)
+static int set_rtc_mmss(unsigned long secs)
 {
-        int real_seconds, real_minutes, mostek_minutes;
-        struct mostek48t02 *regs = (struct mostek48t02 *)mstk48t02_regs;
-        unsigned long flags;
+        struct rtc_device *rtc = rtc_class_open("rtc0");
 
-        spin_lock_irqsave(&mostek_lock, flags);
-        /* Read the current RTC minutes. */
-        regs->creg |= MSTK_CREG_READ;
-        mostek_minutes = MSTK_REG_MIN(regs);
-        regs->creg &= ~MSTK_CREG_READ;
+        if (rtc)
+                return rtc_set_mmss(rtc, secs);
 
-        /*
-         * since we're only adjusting minutes and seconds,
-         * don't interfere with hour overflow. This avoids
-         * messing with unknown time zones but requires your
-         * RTC not to be off by more than 15 minutes
-         */
-        real_seconds = nowtime % 60;
-        real_minutes = nowtime / 60;
-        if (((abs(real_minutes - mostek_minutes) + 15)/30) & 1)
-                real_minutes += 30;     /* correct for half hour time zone */
-        real_minutes %= 60;
-
-        if (abs(real_minutes - mostek_minutes) < 30) {
-                regs->creg |= MSTK_CREG_WRITE;
-                MSTK_SET_REG_SEC(regs,real_seconds);
-                MSTK_SET_REG_MIN(regs,real_minutes);
-                regs->creg &= ~MSTK_CREG_WRITE;
-                spin_unlock_irqrestore(&mostek_lock, flags);
-                return 0;
-        } else {
-                spin_unlock_irqrestore(&mostek_lock, flags);
-                return -1;
-        }
+        return -1;
 }