--- /dev/null
+/*
+ * rtc-twl4030.c -- TWL4030 Real Time Clock interface
+ *
+ * Copyright (C) 2007 MontaVista Software, Inc
+ * Author: Alexandre Rusev <source@mvista.com>
+ *
+ * Based on original TI driver twl4030-rtc.c
+ * Copyright (C) 2006 Texas Instruments, Inc.
+ *
+ * Based on rtc-omap.c
+ * Copyright (C) 2003 MontaVista Software, Inc.
+ * Author: George G. Davis <gdavis@mvista.com> or <source@mvista.com>
+ * Copyright (C) 2006 David Brownell
+ *
+ * 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/kernel.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/rtc.h>
+#include <linux/bcd.h>
+#include <linux/platform_device.h>
+#include <linux/interrupt.h>
+
+#include <linux/i2c/twl4030.h>
+
+
+/*
+ * RTC block register offsets (use TWL_MODULE_RTC)
+ */
+#define REG_SECONDS_REG 0x00
+#define REG_MINUTES_REG 0x01
+#define REG_HOURS_REG 0x02
+#define REG_DAYS_REG 0x03
+#define REG_MONTHS_REG 0x04
+#define REG_YEARS_REG 0x05
+#define REG_WEEKS_REG 0x06
+
+#define REG_ALARM_SECONDS_REG 0x07
+#define REG_ALARM_MINUTES_REG 0x08
+#define REG_ALARM_HOURS_REG 0x09
+#define REG_ALARM_DAYS_REG 0x0A
+#define REG_ALARM_MONTHS_REG 0x0B
+#define REG_ALARM_YEARS_REG 0x0C
+
+#define REG_RTC_CTRL_REG 0x0D
+#define REG_RTC_STATUS_REG 0x0E
+#define REG_RTC_INTERRUPTS_REG 0x0F
+
+#define REG_RTC_COMP_LSB_REG 0x10
+#define REG_RTC_COMP_MSB_REG 0x11
+
+/* RTC_CTRL_REG bitfields */
+#define BIT_RTC_CTRL_REG_STOP_RTC_M 0x01
+#define BIT_RTC_CTRL_REG_ROUND_30S_M 0x02
+#define BIT_RTC_CTRL_REG_AUTO_COMP_M 0x04
+#define BIT_RTC_CTRL_REG_MODE_12_24_M 0x08
+#define BIT_RTC_CTRL_REG_TEST_MODE_M 0x10
+#define BIT_RTC_CTRL_REG_SET_32_COUNTER_M 0x20
+#define BIT_RTC_CTRL_REG_GET_TIME_M 0x40
+
+/* RTC_STATUS_REG bitfields */
+#define BIT_RTC_STATUS_REG_RUN_M 0x02
+#define BIT_RTC_STATUS_REG_1S_EVENT_M 0x04
+#define BIT_RTC_STATUS_REG_1M_EVENT_M 0x08
+#define BIT_RTC_STATUS_REG_1H_EVENT_M 0x10
+#define BIT_RTC_STATUS_REG_1D_EVENT_M 0x20
+#define BIT_RTC_STATUS_REG_ALARM_M 0x40
+#define BIT_RTC_STATUS_REG_POWER_UP_M 0x80
+
+/* RTC_INTERRUPTS_REG bitfields */
+#define BIT_RTC_INTERRUPTS_REG_EVERY_M 0x03
+#define BIT_RTC_INTERRUPTS_REG_IT_TIMER_M 0x04
+#define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M 0x08
+
+
+/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
+#define ALL_TIME_REGS 6
+
+/*----------------------------------------------------------------------*/
+
+/*
+ * Supports 1 byte read from TWL4030 RTC register.
+ */
+static int twl4030_rtc_read_u8(u8 *data, u8 reg)
+{
+ int ret;
+
+ ret = twl4030_i2c_read_u8(TWL4030_MODULE_RTC, data, reg);
+ if (ret < 0)
+ pr_err("twl4030_rtc: Could not read TWL4030"
+ "register %X - error %d\n", reg, ret);
+ return ret;
+}
+
+/*
+ * Supports 1 byte write to TWL4030 RTC registers.
+ */
+static int twl4030_rtc_write_u8(u8 data, u8 reg)
+{
+ int ret;
+
+ ret = twl4030_i2c_write_u8(TWL4030_MODULE_RTC, data, reg);
+ if (ret < 0)
+ pr_err("twl4030_rtc: Could not write TWL4030"
+ "register %X - error %d\n", reg, ret);
+ return ret;
+}
+
+/*
+ * Cache the value for timer/alarm interrupts register; this is
+ * only changed by callers holding rtc ops lock (or resume).
+ */
+static unsigned char rtc_irq_bits;
+
+/*
+ * Enable timer and/or alarm interrupts.
+ */
+static int set_rtc_irq_bit(unsigned char bit)
+{
+ unsigned char val;
+ int ret;
+
+ val = rtc_irq_bits | bit;
+ ret = twl4030_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
+ if (ret == 0)
+ rtc_irq_bits = val;
+
+ return ret;
+}
+
+/*
+ * Disable timer and/or alarm interrupts.
+ */
+static int mask_rtc_irq_bit(unsigned char bit)
+{
+ unsigned char val;
+ int ret;
+
+ val = rtc_irq_bits & ~bit;
+ ret = twl4030_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
+ if (ret == 0)
+ rtc_irq_bits = val;
+
+ return ret;
+}
+
+static inline int twl4030_rtc_alarm_irq_set_state(int enabled)
+{
+ int ret;
+
+ if (enabled)
+ ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+ else
+ ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+
+ return ret;
+}
+
+static inline int twl4030_rtc_irq_set_state(int enabled)
+{
+ int ret;
+
+ if (enabled)
+ ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+ else
+ ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+
+ return ret;
+}
+
+/*
+ * Gets current TWL4030 RTC time and date parameters.
+ *
+ * The RTC's time/alarm representation is not what gmtime(3) requires
+ * Linux to use:
+ *
+ * - Months are 1..12 vs Linux 0-11
+ * - Years are 0..99 vs Linux 1900..N (we assume 21st century)
+ */
+static int twl4030_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ unsigned char rtc_data[ALL_TIME_REGS + 1];
+ int ret;
+ u8 save_control;
+
+ ret = twl4030_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
+ if (ret < 0)
+ return ret;
+
+ save_control |= BIT_RTC_CTRL_REG_GET_TIME_M;
+
+ ret = twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
+ if (ret < 0)
+ return ret;
+
+ ret = twl4030_i2c_read(TWL4030_MODULE_RTC, rtc_data,
+ REG_SECONDS_REG, ALL_TIME_REGS);
+
+ if (ret < 0) {
+ dev_err(dev, "rtc_read_time error %d\n", ret);
+ return ret;
+ }
+
+ tm->tm_sec = bcd2bin(rtc_data[0]);
+ tm->tm_min = bcd2bin(rtc_data[1]);
+ tm->tm_hour = bcd2bin(rtc_data[2]);
+ tm->tm_mday = bcd2bin(rtc_data[3]);
+ tm->tm_mon = bcd2bin(rtc_data[4]) - 1;
+ tm->tm_year = bcd2bin(rtc_data[5]) + 100;
+
+ return ret;
+}
+
+static int twl4030_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ unsigned char save_control;
+ unsigned char rtc_data[ALL_TIME_REGS + 1];
+ int ret;
+
+ rtc_data[1] = bin2bcd(tm->tm_sec);
+ rtc_data[2] = bin2bcd(tm->tm_min);
+ rtc_data[3] = bin2bcd(tm->tm_hour);
+ rtc_data[4] = bin2bcd(tm->tm_mday);
+ rtc_data[5] = bin2bcd(tm->tm_mon + 1);
+ rtc_data[6] = bin2bcd(tm->tm_year - 100);
+
+ /* Stop RTC while updating the TC registers */
+ ret = twl4030_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
+ if (ret < 0)
+ goto out;
+
+ save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M;
+ twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
+ if (ret < 0)
+ goto out;
+
+ /* update all the time registers in one shot */
+ ret = twl4030_i2c_write(TWL4030_MODULE_RTC, rtc_data,
+ REG_SECONDS_REG, ALL_TIME_REGS);
+ if (ret < 0) {
+ dev_err(dev, "rtc_set_time error %d\n", ret);
+ goto out;
+ }
+
+ /* Start back RTC */
+ save_control |= BIT_RTC_CTRL_REG_STOP_RTC_M;
+ ret = twl4030_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
+
+out:
+ return ret;
+}
+
+/*
+ * Gets current TWL4030 RTC alarm time.
+ */
+static int twl4030_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ unsigned char rtc_data[ALL_TIME_REGS + 1];
+ int ret;
+
+ ret = twl4030_i2c_read(TWL4030_MODULE_RTC, rtc_data,
+ REG_ALARM_SECONDS_REG, ALL_TIME_REGS);
+ if (ret < 0) {
+ dev_err(dev, "rtc_read_alarm error %d\n", ret);
+ return ret;
+ }
+
+ /* some of these fields may be wildcard/"match all" */
+ alm->time.tm_sec = bcd2bin(rtc_data[0]);
+ alm->time.tm_min = bcd2bin(rtc_data[1]);
+ alm->time.tm_hour = bcd2bin(rtc_data[2]);
+ alm->time.tm_mday = bcd2bin(rtc_data[3]);
+ alm->time.tm_mon = bcd2bin(rtc_data[4]) - 1;
+ alm->time.tm_year = bcd2bin(rtc_data[5]) + 100;
+
+ /* report cached alarm enable state */
+ if (rtc_irq_bits & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M)
+ alm->enabled = 1;
+
+ return ret;
+}
+
+static int twl4030_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ unsigned char alarm_data[ALL_TIME_REGS + 1];
+ int ret;
+
+ ret = twl4030_rtc_alarm_irq_set_state(0);
+ if (ret)
+ goto out;
+
+ alarm_data[1] = bin2bcd(alm->time.tm_sec);
+ alarm_data[2] = bin2bcd(alm->time.tm_min);
+ alarm_data[3] = bin2bcd(alm->time.tm_hour);
+ alarm_data[4] = bin2bcd(alm->time.tm_mday);
+ alarm_data[5] = bin2bcd(alm->time.tm_mon + 1);
+ alarm_data[6] = bin2bcd(alm->time.tm_year - 100);
+
+ /* update all the alarm registers in one shot */
+ ret = twl4030_i2c_write(TWL4030_MODULE_RTC, alarm_data,
+ REG_ALARM_SECONDS_REG, ALL_TIME_REGS);
+ if (ret) {
+ dev_err(dev, "rtc_set_alarm error %d\n", ret);
+ goto out;
+ }
+
+ if (alm->enabled)
+ ret = twl4030_rtc_alarm_irq_set_state(1);
+out:
+ return ret;
+}
+
+#ifdef CONFIG_RTC_INTF_DEV
+
+static int twl4030_rtc_ioctl(struct device *dev, unsigned int cmd,
+ unsigned long arg)
+{
+ switch (cmd) {
+ case RTC_AIE_OFF:
+ return twl4030_rtc_alarm_irq_set_state(0);
+ case RTC_AIE_ON:
+ return twl4030_rtc_alarm_irq_set_state(1);
+ case RTC_UIE_OFF:
+ return twl4030_rtc_irq_set_state(0);
+ case RTC_UIE_ON:
+ return twl4030_rtc_irq_set_state(1);
+
+ default:
+ return -ENOIOCTLCMD;
+ }
+}
+
+#else
+#define omap_rtc_ioctl NULL
+#endif
+
+static irqreturn_t twl4030_rtc_interrupt(int irq, void *rtc)
+{
+ unsigned long events = 0;
+ int ret = IRQ_NONE;
+ int res;
+ u8 rd_reg;
+
+#ifdef CONFIG_LOCKDEP
+ /* WORKAROUND for lockdep forcing IRQF_DISABLED on us, which
+ * we don't want and can't tolerate. Although it might be
+ * friendlier not to borrow this thread context...
+ */
+ local_irq_enable();
+#endif
+
+ res = twl4030_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
+ if (res)
+ goto out;
+ /*
+ * Figure out source of interrupt: ALARM or TIMER in RTC_STATUS_REG.
+ * only one (ALARM or RTC) interrupt source may be enabled
+ * at time, we also could check our results
+ * by reading RTS_INTERRUPTS_REGISTER[IT_TIMER,IT_ALARM]
+ */
+ if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
+ events |= RTC_IRQF | RTC_AF;
+ else
+ events |= RTC_IRQF | RTC_UF;
+
+ res = twl4030_rtc_write_u8(rd_reg | BIT_RTC_STATUS_REG_ALARM_M,
+ REG_RTC_STATUS_REG);
+ if (res)
+ goto out;
+
+ /* Clear on Read enabled. RTC_IT bit of TWL4030_INT_PWR_ISR1
+ * needs 2 reads to clear the interrupt. One read is done in
+ * do_twl4030_pwrirq(). Doing the second read, to clear
+ * the bit.
+ *
+ * FIXME the reason PWR_ISR1 needs an extra read is that
+ * RTC_IF retriggered until we cleared REG_ALARM_M above.
+ * But re-reading like this is a bad hack; by doing so we
+ * risk wrongly clearing status for some other IRQ (losing
+ * the interrupt). Be smarter about handling RTC_UF ...
+ */
+ res = twl4030_i2c_read_u8(TWL4030_MODULE_INT,
+ &rd_reg, TWL4030_INT_PWR_ISR1);
+ if (res)
+ goto out;
+
+ /* Notify RTC core on event */
+ rtc_update_irq(rtc, 1, events);
+
+ ret = IRQ_HANDLED;
+out:
+ return ret;
+}
+
+static struct rtc_class_ops twl4030_rtc_ops = {
+ .ioctl = twl4030_rtc_ioctl,
+ .read_time = twl4030_rtc_read_time,
+ .set_time = twl4030_rtc_set_time,
+ .read_alarm = twl4030_rtc_read_alarm,
+ .set_alarm = twl4030_rtc_set_alarm,
+};
+
+/*----------------------------------------------------------------------*/
+
+static int __devinit twl4030_rtc_probe(struct platform_device *pdev)
+{
+ struct rtc_device *rtc;
+ int ret = 0;
+ int irq = platform_get_irq(pdev, 0);
+ u8 rd_reg;
+
+ if (irq < 0)
+ return irq;
+
+ rtc = rtc_device_register(pdev->name,
+ &pdev->dev, &twl4030_rtc_ops, THIS_MODULE);
+ if (IS_ERR(rtc)) {
+ ret = -EINVAL;
+ dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
+ PTR_ERR(rtc));
+ goto out0;
+
+ }
+
+ platform_set_drvdata(pdev, rtc);
+
+ ret = twl4030_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
+
+ if (ret < 0)
+ goto out1;
+
+ if (rd_reg & BIT_RTC_STATUS_REG_POWER_UP_M)
+ dev_warn(&pdev->dev, "Power up reset detected.\n");
+
+ if (rd_reg & BIT_RTC_STATUS_REG_ALARM_M)
+ dev_warn(&pdev->dev, "Pending Alarm interrupt detected.\n");
+
+ /* Clear RTC Power up reset and pending alarm interrupts */
+ ret = twl4030_rtc_write_u8(rd_reg, REG_RTC_STATUS_REG);
+ if (ret < 0)
+ goto out1;
+
+ ret = request_irq(irq, twl4030_rtc_interrupt,
+ IRQF_TRIGGER_RISING,
+ rtc->dev.bus_id, rtc);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "IRQ is not free.\n");
+ goto out1;
+ }
+
+ /* Check RTC module status, Enable if it is off */
+ ret = twl4030_rtc_read_u8(&rd_reg, REG_RTC_CTRL_REG);
+ if (ret < 0)
+ goto out2;
+
+ if (!(rd_reg & BIT_RTC_CTRL_REG_STOP_RTC_M)) {
+ dev_info(&pdev->dev, "Enabling TWL4030-RTC.\n");
+ rd_reg = BIT_RTC_CTRL_REG_STOP_RTC_M;
+ ret = twl4030_rtc_write_u8(rd_reg, REG_RTC_CTRL_REG);
+ if (ret < 0)
+ goto out2;
+ }
+
+ /* init cached IRQ enable bits */
+ ret = twl4030_rtc_read_u8(&rtc_irq_bits, REG_RTC_INTERRUPTS_REG);
+ if (ret < 0)
+ goto out2;
+
+ return ret;
+
+
+out2:
+ free_irq(irq, rtc);
+out1:
+ rtc_device_unregister(rtc);
+out0:
+ return ret;
+}
+
+/*
+ * Disable all TWL4030 RTC module interrupts.
+ * Sets status flag to free.
+ */
+static int __devexit twl4030_rtc_remove(struct platform_device *pdev)
+{
+ /* leave rtc running, but disable irqs */
+ struct rtc_device *rtc = platform_get_drvdata(pdev);
+ int irq = platform_get_irq(pdev, 0);
+
+ mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+ mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+
+ free_irq(irq, rtc);
+
+ rtc_device_unregister(rtc);
+ platform_set_drvdata(pdev, NULL);
+ return 0;
+}
+
+static void twl4030_rtc_shutdown(struct platform_device *pdev)
+{
+ mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M |
+ BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+}
+
+#ifdef CONFIG_PM
+
+static unsigned char irqstat;
+
+static int twl4030_rtc_suspend(struct platform_device *pdev, pm_message_t state)
+{
+ irqstat = rtc_irq_bits;
+
+ /* REVISIT alarm may need to wake us from sleep */
+ mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M |
+ BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+ return 0;
+}
+
+static int twl4030_rtc_resume(struct platform_device *pdev)
+{
+ set_rtc_irq_bit(irqstat);
+ return 0;
+}
+
+#else
+#define twl4030_rtc_suspend NULL
+#define twl4030_rtc_resume NULL
+#endif
+
+MODULE_ALIAS("platform:twl4030_rtc");
+
+static struct platform_driver twl4030rtc_driver = {
+ .probe = twl4030_rtc_probe,
+ .remove = __devexit_p(twl4030_rtc_remove),
+ .shutdown = twl4030_rtc_shutdown,
+ .suspend = twl4030_rtc_suspend,
+ .resume = twl4030_rtc_resume,
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = "twl4030_rtc",
+ },
+};
+
+static int __init twl4030_rtc_init(void)
+{
+ return platform_driver_register(&twl4030rtc_driver);
+}
+module_init(twl4030_rtc_init);
+
+static void __exit twl4030_rtc_exit(void)
+{
+ platform_driver_unregister(&twl4030rtc_driver);
+}
+module_exit(twl4030_rtc_exit);
+
+MODULE_AUTHOR("Texas Instruments, MontaVista Software");
+MODULE_LICENSE("GPL");
projects / linux-2.6-microblaze.git / commitdiff