[PATCH] RTC subsystem: SA1100/PXA2XX driver
Richard Purdie [Mon, 27 Mar 2006 09:16:46 +0000 (01:16 -0800)]
Add an RTC subsystem driver for the ARM SA1100/PXA2XX processor RTC.

Signed-off-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/arm/mach-pxa/generic.c
arch/arm/mach-sa1100/generic.c
drivers/rtc/Kconfig
drivers/rtc/Makefile
drivers/rtc/rtc-sa1100.c [new file with mode: 0644]

index 9b48a90..5efa847 100644 (file)
@@ -319,6 +319,11 @@ void __init pxa_set_ficp_info(struct pxaficp_platform_data *info)
        pxaficp_device.dev.platform_data = info;
 }
 
+static struct platform_device pxartc_device = {
+       .name           = "sa1100-rtc",
+       .id             = -1,
+};
+
 static struct platform_device *devices[] __initdata = {
        &pxamci_device,
        &udc_device,
@@ -329,6 +334,7 @@ static struct platform_device *devices[] __initdata = {
        &pxaficp_device,
        &i2c_device,
        &i2s_device,
+       &pxartc_device,
 };
 
 static int __init pxa_init(void)
index 2abdc41..9ea7155 100644 (file)
@@ -324,6 +324,11 @@ void sa11x0_set_irda_data(struct irda_platform_data *irda)
        sa11x0ir_device.dev.platform_data = irda;
 }
 
+static struct platform_device sa11x0rtc_device = {
+       .name           = "sa1100-rtc",
+       .id             = -1,
+};
+
 static struct platform_device *sa11x0_devices[] __initdata = {
        &sa11x0udc_device,
        &sa11x0uart1_device,
@@ -333,6 +338,7 @@ static struct platform_device *sa11x0_devices[] __initdata = {
        &sa11x0pcmcia_device,
        &sa11x0fb_device,
        &sa11x0mtd_device,
+       &sa11x0rtc_device,
 };
 
 static int __init sa1100_init(void)
index b399259..166232a 100644 (file)
@@ -127,6 +127,15 @@ config RTC_DRV_EP93XX
          This driver can also be built as a module. If so, the module
          will be called rtc-ep93xx.
 
+config RTC_DRV_SA1100
+       tristate "SA11x0/PXA2xx"
+       depends on RTC_CLASS && (ARCH_SA1100 || ARCH_PXA)
+       help
+         If you say Y here you will get access to the real time clock
+         built into your SA11x0 or PXA2xx CPU.
+
+         To compile this driver as a module, choose M here: the
+         module will be called rtc-sa1100.
 
 config RTC_DRV_TEST
        tristate "Test driver/device"
index 38b4d87..56820d1 100644 (file)
@@ -17,3 +17,4 @@ obj-$(CONFIG_RTC_DRV_DS1672)  += rtc-ds1672.o
 obj-$(CONFIG_RTC_DRV_PCF8563)  += rtc-pcf8563.o
 obj-$(CONFIG_RTC_DRV_RS5C372)  += rtc-rs5c372.o
 obj-$(CONFIG_RTC_DRV_EP93XX)   += rtc-ep93xx.o
+obj-$(CONFIG_RTC_DRV_SA1100)   += rtc-sa1100.o
diff --git a/drivers/rtc/rtc-sa1100.c b/drivers/rtc/rtc-sa1100.c
new file mode 100644 (file)
index 0000000..83b2bb4
--- /dev/null
@@ -0,0 +1,388 @@
+/*
+ * Real Time Clock interface for StrongARM SA1x00 and XScale PXA2xx
+ *
+ * Copyright (c) 2000 Nils Faerber
+ *
+ * Based on rtc.c by Paul Gortmaker
+ *
+ * Original Driver by Nils Faerber <nils@kernelconcepts.de>
+ *
+ * Modifications from:
+ *   CIH <cih@coventive.com>
+ *   Nicolas Pitre <nico@cam.org>
+ *   Andrew Christian <andrew.christian@hp.com>
+ *
+ * Converted to the RTC subsystem and Driver Model
+ *   by Richard Purdie <rpurdie@rpsys.net>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <linux/platform_device.h>
+#include <linux/module.h>
+#include <linux/rtc.h>
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/interrupt.h>
+#include <linux/string.h>
+#include <linux/pm.h>
+
+#include <asm/bitops.h>
+#include <asm/hardware.h>
+#include <asm/irq.h>
+#include <asm/rtc.h>
+
+#ifdef CONFIG_ARCH_PXA
+#include <asm/arch/pxa-regs.h>
+#endif
+
+#define TIMER_FREQ             CLOCK_TICK_RATE
+#define RTC_DEF_DIVIDER                32768 - 1
+#define RTC_DEF_TRIM           0
+
+static unsigned long rtc_freq = 1024;
+static struct rtc_time rtc_alarm;
+static spinlock_t sa1100_rtc_lock = SPIN_LOCK_UNLOCKED;
+
+static int rtc_update_alarm(struct rtc_time *alrm)
+{
+       struct rtc_time alarm_tm, now_tm;
+       unsigned long now, time;
+       int ret;
+
+       do {
+               now = RCNR;
+               rtc_time_to_tm(now, &now_tm);
+               rtc_next_alarm_time(&alarm_tm, &now_tm, alrm);
+               ret = rtc_tm_to_time(&alarm_tm, &time);
+               if (ret != 0)
+                       break;
+
+               RTSR = RTSR & (RTSR_HZE|RTSR_ALE|RTSR_AL);
+               RTAR = time;
+       } while (now != RCNR);
+
+       return ret;
+}
+
+static irqreturn_t sa1100_rtc_interrupt(int irq, void *dev_id,
+               struct pt_regs *regs)
+{
+       struct platform_device *pdev = to_platform_device(dev_id);
+       struct rtc_device *rtc = platform_get_drvdata(pdev);
+       unsigned int rtsr;
+       unsigned long events = 0;
+
+       spin_lock(&sa1100_rtc_lock);
+
+       rtsr = RTSR;
+       /* clear interrupt sources */
+       RTSR = 0;
+       RTSR = (RTSR_AL | RTSR_HZ) & (rtsr >> 2);
+
+       /* clear alarm interrupt if it has occurred */
+       if (rtsr & RTSR_AL)
+               rtsr &= ~RTSR_ALE;
+       RTSR = rtsr & (RTSR_ALE | RTSR_HZE);
+
+       /* update irq data & counter */
+       if (rtsr & RTSR_AL)
+               events |= RTC_AF | RTC_IRQF;
+       if (rtsr & RTSR_HZ)
+               events |= RTC_UF | RTC_IRQF;
+
+       rtc_update_irq(&rtc->class_dev, 1, events);
+
+       if (rtsr & RTSR_AL && rtc_periodic_alarm(&rtc_alarm))
+               rtc_update_alarm(&rtc_alarm);
+
+       spin_unlock(&sa1100_rtc_lock);
+
+       return IRQ_HANDLED;
+}
+
+static int rtc_timer1_count;
+
+static irqreturn_t timer1_interrupt(int irq, void *dev_id,
+               struct pt_regs *regs)
+{
+       struct platform_device *pdev = to_platform_device(dev_id);
+       struct rtc_device *rtc = platform_get_drvdata(pdev);
+
+       /*
+        * If we match for the first time, rtc_timer1_count will be 1.
+        * Otherwise, we wrapped around (very unlikely but
+        * still possible) so compute the amount of missed periods.
+        * The match reg is updated only when the data is actually retrieved
+        * to avoid unnecessary interrupts.
+        */
+       OSSR = OSSR_M1; /* clear match on timer1 */
+
+       rtc_update_irq(&rtc->class_dev, rtc_timer1_count, RTC_PF | RTC_IRQF);
+
+       if (rtc_timer1_count == 1)
+               rtc_timer1_count = (rtc_freq * ((1<<30)/(TIMER_FREQ>>2)));
+
+       return IRQ_HANDLED;
+}
+
+static int sa1100_rtc_read_callback(struct device *dev, int data)
+{
+       if (data & RTC_PF) {
+               /* interpolate missed periods and set match for the next */
+               unsigned long period = TIMER_FREQ/rtc_freq;
+               unsigned long oscr = OSCR;
+               unsigned long osmr1 = OSMR1;
+               unsigned long missed = (oscr - osmr1)/period;
+               data += missed << 8;
+               OSSR = OSSR_M1; /* clear match on timer 1 */
+               OSMR1 = osmr1 + (missed + 1)*period;
+               /* Ensure we didn't miss another match in the mean time.
+                * Here we compare (match - OSCR) 8 instead of 0 --
+                * see comment in pxa_timer_interrupt() for explanation.
+                */
+               while( (signed long)((osmr1 = OSMR1) - OSCR) <= 8 ) {
+                       data += 0x100;
+                       OSSR = OSSR_M1; /* clear match on timer 1 */
+                       OSMR1 = osmr1 + period;
+               }
+       }
+       return data;
+}
+
+static int sa1100_rtc_open(struct device *dev)
+{
+       int ret;
+
+       ret = request_irq(IRQ_RTC1Hz, sa1100_rtc_interrupt, SA_INTERRUPT,
+                               "rtc 1Hz", dev);
+       if (ret) {
+               printk(KERN_ERR "rtc: IRQ%d already in use.\n", IRQ_RTC1Hz);
+               goto fail_ui;
+       }
+       ret = request_irq(IRQ_RTCAlrm, sa1100_rtc_interrupt, SA_INTERRUPT,
+                               "rtc Alrm", dev);
+       if (ret) {
+               printk(KERN_ERR "rtc: IRQ%d already in use.\n", IRQ_RTCAlrm);
+               goto fail_ai;
+       }
+       ret = request_irq(IRQ_OST1, timer1_interrupt, SA_INTERRUPT,
+                               "rtc timer", dev);
+       if (ret) {
+               printk(KERN_ERR "rtc: IRQ%d already in use.\n", IRQ_OST1);
+               goto fail_pi;
+       }
+       return 0;
+
+ fail_pi:
+       free_irq(IRQ_RTCAlrm, NULL);
+ fail_ai:
+       free_irq(IRQ_RTC1Hz, NULL);
+ fail_ui:
+       return ret;
+}
+
+static void sa1100_rtc_release(struct device *dev)
+{
+       spin_lock_irq(&sa1100_rtc_lock);
+       RTSR = 0;
+       OIER &= ~OIER_E1;
+       OSSR = OSSR_M1;
+       spin_unlock_irq(&sa1100_rtc_lock);
+
+       free_irq(IRQ_OST1, dev);
+       free_irq(IRQ_RTCAlrm, dev);
+       free_irq(IRQ_RTC1Hz, dev);
+}
+
+
+static int sa1100_rtc_ioctl(struct device *dev, unsigned int cmd,
+               unsigned long arg)
+{
+       switch(cmd) {
+       case RTC_AIE_OFF:
+               spin_lock_irq(&sa1100_rtc_lock);
+               RTSR &= ~RTSR_ALE;
+               spin_unlock_irq(&sa1100_rtc_lock);
+               return 0;
+       case RTC_AIE_ON:
+               spin_lock_irq(&sa1100_rtc_lock);
+               RTSR |= RTSR_ALE;
+               spin_unlock_irq(&sa1100_rtc_lock);
+               return 0;
+       case RTC_UIE_OFF:
+               spin_lock_irq(&sa1100_rtc_lock);
+               RTSR &= ~RTSR_HZE;
+               spin_unlock_irq(&sa1100_rtc_lock);
+               return 0;
+       case RTC_UIE_ON:
+               spin_lock_irq(&sa1100_rtc_lock);
+               RTSR |= RTSR_HZE;
+               spin_unlock_irq(&sa1100_rtc_lock);
+               return 0;
+       case RTC_PIE_OFF:
+               spin_lock_irq(&sa1100_rtc_lock);
+               OIER &= ~OIER_E1;
+               spin_unlock_irq(&sa1100_rtc_lock);
+               return 0;
+       case RTC_PIE_ON:
+               if ((rtc_freq > 64) && !capable(CAP_SYS_RESOURCE))
+                       return -EACCES;
+               spin_lock_irq(&sa1100_rtc_lock);
+               OSMR1 = TIMER_FREQ/rtc_freq + OSCR;
+               OIER |= OIER_E1;
+               rtc_timer1_count = 1;
+               spin_unlock_irq(&sa1100_rtc_lock);
+               return 0;
+       case RTC_IRQP_READ:
+               return put_user(rtc_freq, (unsigned long *)arg);
+       case RTC_IRQP_SET:
+               if (arg < 1 || arg > TIMER_FREQ)
+                       return -EINVAL;
+               if ((arg > 64) && (!capable(CAP_SYS_RESOURCE)))
+                       return -EACCES;
+               rtc_freq = arg;
+               return 0;
+       }
+       return -EINVAL;
+}
+
+static int sa1100_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+       rtc_time_to_tm(RCNR, tm);
+       return 0;
+}
+
+static int sa1100_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+       unsigned long time;
+       int ret;
+
+       ret = rtc_tm_to_time(tm, &time);
+       if (ret == 0)
+               RCNR = time;
+       return ret;
+}
+
+static int sa1100_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       memcpy(&alrm->time, &rtc_alarm, sizeof(struct rtc_time));
+       alrm->pending = RTSR & RTSR_AL ? 1 : 0;
+       return 0;
+}
+
+static int sa1100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
+{
+       int ret;
+
+       spin_lock_irq(&sa1100_rtc_lock);
+       ret = rtc_update_alarm(&alrm->time);
+       if (ret == 0) {
+               memcpy(&rtc_alarm, &alrm->time, sizeof(struct rtc_time));
+
+               if (alrm->enabled)
+                       enable_irq_wake(IRQ_RTCAlrm);
+               else
+                       disable_irq_wake(IRQ_RTCAlrm);
+       }
+       spin_unlock_irq(&sa1100_rtc_lock);
+
+       return ret;
+}
+
+static int sa1100_rtc_proc(struct device *dev, struct seq_file *seq)
+{
+       seq_printf(seq, "trim/divider\t: 0x%08x\n", RTTR);
+       seq_printf(seq, "alarm_IRQ\t: %s\n",
+                       (RTSR & RTSR_ALE) ? "yes" : "no" );
+       seq_printf(seq, "update_IRQ\t: %s\n",
+                       (RTSR & RTSR_HZE) ? "yes" : "no");
+       seq_printf(seq, "periodic_IRQ\t: %s\n",
+                       (OIER & OIER_E1) ? "yes" : "no");
+       seq_printf(seq, "periodic_freq\t: %ld\n", rtc_freq);
+
+       return 0;
+}
+
+static struct rtc_class_ops sa1100_rtc_ops = {
+       .open = sa1100_rtc_open,
+       .read_callback = sa1100_rtc_read_callback,
+       .release = sa1100_rtc_release,
+       .ioctl = sa1100_rtc_ioctl,
+       .read_time = sa1100_rtc_read_time,
+       .set_time = sa1100_rtc_set_time,
+       .read_alarm = sa1100_rtc_read_alarm,
+       .set_alarm = sa1100_rtc_set_alarm,
+       .proc = sa1100_rtc_proc,
+};
+
+static int sa1100_rtc_probe(struct platform_device *pdev)
+{
+       struct rtc_device *rtc;
+
+       /*
+        * According to the manual we should be able to let RTTR be zero
+        * and then a default diviser for a 32.768KHz clock is used.
+        * Apparently this doesn't work, at least for my SA1110 rev 5.
+        * If the clock divider is uninitialized then reset it to the
+        * default value to get the 1Hz clock.
+        */
+       if (RTTR == 0) {
+               RTTR = RTC_DEF_DIVIDER + (RTC_DEF_TRIM << 16);
+               printk(KERN_WARNING "rtc: warning: initializing default clock divider/trim value\n");
+               /* The current RTC value probably doesn't make sense either */
+               RCNR = 0;
+       }
+
+       rtc = rtc_device_register(pdev->name, &pdev->dev, &sa1100_rtc_ops,
+                               THIS_MODULE);
+
+       if (IS_ERR(rtc)) {
+               dev_err(&pdev->dev, "Unable to register the RTC device\n");
+               return PTR_ERR(rtc);
+       }
+
+       platform_set_drvdata(pdev, rtc);
+
+       dev_info(&pdev->dev, "SA11xx/PXA2xx RTC Registered\n");
+
+       return 0;
+}
+
+static int sa1100_rtc_remove(struct platform_device *pdev)
+{
+       struct rtc_device *rtc = platform_get_drvdata(pdev);
+
+       if (rtc)
+               rtc_device_unregister(rtc);
+
+       return 0;
+}
+
+static struct platform_driver sa1100_rtc_driver = {
+       .probe          = sa1100_rtc_probe,
+       .remove         = sa1100_rtc_remove,
+       .driver         = {
+               .name           = "sa1100-rtc",
+       },
+};
+
+static int __init sa1100_rtc_init(void)
+{
+       return platform_driver_register(&sa1100_rtc_driver);
+}
+
+static void __exit sa1100_rtc_exit(void)
+{
+       platform_driver_unregister(&sa1100_rtc_driver);
+}
+
+module_init(sa1100_rtc_init);
+module_exit(sa1100_rtc_exit);
+
+MODULE_AUTHOR("Richard Purdie <rpurdie@rpsys.net>");
+MODULE_DESCRIPTION("SA11x0/PXA2xx Realtime Clock Driver (RTC)");
+MODULE_LICENSE("GPL");