1 files changed, 564 insertions, 0 deletions

diff --git a/drivers/rtc/rtc-twl4030.c b/drivers/rtc/rtc-twl4030.c
new file mode 100644
index 000000000000..abe87a4d2665
--- /dev/null
+++ b/drivers/rtc/rtc-twl4030.c
@@ -0,0 +1,564 @@
+/*
+ * 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");