--- /dev/null
+/*
+ * rtc-twl.c -- TWL 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.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/kernel.h>
+#include <linux/errno.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/of.h>
+
+#include <linux/i2c/twl.h>
+
+
+/*
+ * RTC block register offsets (use TWL_MODULE_RTC)
+ */
+enum {
+ REG_SECONDS_REG = 0,
+ REG_MINUTES_REG,
+ REG_HOURS_REG,
+ REG_DAYS_REG,
+ REG_MONTHS_REG,
+ REG_YEARS_REG,
+ REG_WEEKS_REG,
+
+ REG_ALARM_SECONDS_REG,
+ REG_ALARM_MINUTES_REG,
+ REG_ALARM_HOURS_REG,
+ REG_ALARM_DAYS_REG,
+ REG_ALARM_MONTHS_REG,
+ REG_ALARM_YEARS_REG,
+
+ REG_RTC_CTRL_REG,
+ REG_RTC_STATUS_REG,
+ REG_RTC_INTERRUPTS_REG,
+
+ REG_RTC_COMP_LSB_REG,
+ REG_RTC_COMP_MSB_REG,
+};
+static const u8 twl4030_rtc_reg_map[] = {
+ [REG_SECONDS_REG] = 0x00,
+ [REG_MINUTES_REG] = 0x01,
+ [REG_HOURS_REG] = 0x02,
+ [REG_DAYS_REG] = 0x03,
+ [REG_MONTHS_REG] = 0x04,
+ [REG_YEARS_REG] = 0x05,
+ [REG_WEEKS_REG] = 0x06,
+
+ [REG_ALARM_SECONDS_REG] = 0x07,
+ [REG_ALARM_MINUTES_REG] = 0x08,
+ [REG_ALARM_HOURS_REG] = 0x09,
+ [REG_ALARM_DAYS_REG] = 0x0A,
+ [REG_ALARM_MONTHS_REG] = 0x0B,
+ [REG_ALARM_YEARS_REG] = 0x0C,
+
+ [REG_RTC_CTRL_REG] = 0x0D,
+ [REG_RTC_STATUS_REG] = 0x0E,
+ [REG_RTC_INTERRUPTS_REG] = 0x0F,
+
+ [REG_RTC_COMP_LSB_REG] = 0x10,
+ [REG_RTC_COMP_MSB_REG] = 0x11,
+};
+static const u8 twl6030_rtc_reg_map[] = {
+ [REG_SECONDS_REG] = 0x00,
+ [REG_MINUTES_REG] = 0x01,
+ [REG_HOURS_REG] = 0x02,
+ [REG_DAYS_REG] = 0x03,
+ [REG_MONTHS_REG] = 0x04,
+ [REG_YEARS_REG] = 0x05,
+ [REG_WEEKS_REG] = 0x06,
+
+ [REG_ALARM_SECONDS_REG] = 0x08,
+ [REG_ALARM_MINUTES_REG] = 0x09,
+ [REG_ALARM_HOURS_REG] = 0x0A,
+ [REG_ALARM_DAYS_REG] = 0x0B,
+ [REG_ALARM_MONTHS_REG] = 0x0C,
+ [REG_ALARM_YEARS_REG] = 0x0D,
+
+ [REG_RTC_CTRL_REG] = 0x10,
+ [REG_RTC_STATUS_REG] = 0x11,
+ [REG_RTC_INTERRUPTS_REG] = 0x12,
+
+ [REG_RTC_COMP_LSB_REG] = 0x13,
+ [REG_RTC_COMP_MSB_REG] = 0x14,
+};
+
+/* 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
+#define BIT_RTC_CTRL_REG_RTC_V_OPT 0x80
+
+/* 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
+
+/*----------------------------------------------------------------------*/
+static u8 *rtc_reg_map;
+
+/*
+ * Supports 1 byte read from TWL RTC register.
+ */
+static int twl_rtc_read_u8(u8 *data, u8 reg)
+{
+ int ret;
+
+ ret = twl_i2c_read_u8(TWL_MODULE_RTC, data, (rtc_reg_map[reg]));
+ if (ret < 0)
+ pr_err("Could not read TWL register %X - error %d\n", reg, ret);
+ return ret;
+}
+
+/*
+ * Supports 1 byte write to TWL RTC registers.
+ */
+static int twl_rtc_write_u8(u8 data, u8 reg)
+{
+ int ret;
+
+ ret = twl_i2c_write_u8(TWL_MODULE_RTC, data, (rtc_reg_map[reg]));
+ if (ret < 0)
+ pr_err("Could not write TWL 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 1/second update and/or alarm interrupts.
+ */
+static int set_rtc_irq_bit(unsigned char bit)
+{
+ unsigned char val;
+ int ret;
+
+ /* if the bit is set, return from here */
+ if (rtc_irq_bits & bit)
+ return 0;
+
+ val = rtc_irq_bits | bit;
+ val &= ~BIT_RTC_INTERRUPTS_REG_EVERY_M;
+ ret = twl_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
+ if (ret == 0)
+ rtc_irq_bits = val;
+
+ return ret;
+}
+
+/*
+ * Disable update and/or alarm interrupts.
+ */
+static int mask_rtc_irq_bit(unsigned char bit)
+{
+ unsigned char val;
+ int ret;
+
+ /* if the bit is clear, return from here */
+ if (!(rtc_irq_bits & bit))
+ return 0;
+
+ val = rtc_irq_bits & ~bit;
+ ret = twl_rtc_write_u8(val, REG_RTC_INTERRUPTS_REG);
+ if (ret == 0)
+ rtc_irq_bits = val;
+
+ return ret;
+}
+
+static int twl_rtc_alarm_irq_enable(struct device *dev, unsigned enabled)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ int irq = platform_get_irq(pdev, 0);
+ static bool twl_rtc_wake_enabled;
+ int ret;
+
+ if (enabled) {
+ ret = set_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+ if (device_can_wakeup(dev) && !twl_rtc_wake_enabled) {
+ enable_irq_wake(irq);
+ twl_rtc_wake_enabled = true;
+ }
+ } else {
+ ret = mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+ if (twl_rtc_wake_enabled) {
+ disable_irq_wake(irq);
+ twl_rtc_wake_enabled = false;
+ }
+ }
+
+ return ret;
+}
+
+/*
+ * Gets current TWL 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 twl_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ unsigned char rtc_data[ALL_TIME_REGS];
+ int ret;
+ u8 save_control;
+ u8 rtc_control;
+
+ ret = twl_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
+ if (ret < 0) {
+ dev_err(dev, "%s: reading CTRL_REG, error %d\n", __func__, ret);
+ return ret;
+ }
+ /* for twl6030/32 make sure BIT_RTC_CTRL_REG_GET_TIME_M is clear */
+ if (twl_class_is_6030()) {
+ if (save_control & BIT_RTC_CTRL_REG_GET_TIME_M) {
+ save_control &= ~BIT_RTC_CTRL_REG_GET_TIME_M;
+ ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
+ if (ret < 0) {
+ dev_err(dev, "%s clr GET_TIME, error %d\n",
+ __func__, ret);
+ return ret;
+ }
+ }
+ }
+
+ /* Copy RTC counting registers to static registers or latches */
+ rtc_control = save_control | BIT_RTC_CTRL_REG_GET_TIME_M;
+
+ /* for twl6030/32 enable read access to static shadowed registers */
+ if (twl_class_is_6030())
+ rtc_control |= BIT_RTC_CTRL_REG_RTC_V_OPT;
+
+ ret = twl_rtc_write_u8(rtc_control, REG_RTC_CTRL_REG);
+ if (ret < 0) {
+ dev_err(dev, "%s: writing CTRL_REG, error %d\n", __func__, ret);
+ return ret;
+ }
+
+ ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
+ (rtc_reg_map[REG_SECONDS_REG]), ALL_TIME_REGS);
+
+ if (ret < 0) {
+ dev_err(dev, "%s: reading data, error %d\n", __func__, ret);
+ return ret;
+ }
+
+ /* for twl6030 restore original state of rtc control register */
+ if (twl_class_is_6030()) {
+ ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
+ if (ret < 0) {
+ dev_err(dev, "%s: restore CTRL_REG, error %d\n",
+ __func__, 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 twl_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ unsigned char save_control;
+ unsigned char rtc_data[ALL_TIME_REGS];
+ int ret;
+
+ rtc_data[0] = bin2bcd(tm->tm_sec);
+ rtc_data[1] = bin2bcd(tm->tm_min);
+ rtc_data[2] = bin2bcd(tm->tm_hour);
+ rtc_data[3] = bin2bcd(tm->tm_mday);
+ rtc_data[4] = bin2bcd(tm->tm_mon + 1);
+ rtc_data[5] = bin2bcd(tm->tm_year - 100);
+
+ /* Stop RTC while updating the TC registers */
+ ret = twl_rtc_read_u8(&save_control, REG_RTC_CTRL_REG);
+ if (ret < 0)
+ goto out;
+
+ save_control &= ~BIT_RTC_CTRL_REG_STOP_RTC_M;
+ ret = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
+ if (ret < 0)
+ goto out;
+
+ /* update all the time registers in one shot */
+ ret = twl_i2c_write(TWL_MODULE_RTC, rtc_data,
+ (rtc_reg_map[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 = twl_rtc_write_u8(save_control, REG_RTC_CTRL_REG);
+
+out:
+ return ret;
+}
+
+/*
+ * Gets current TWL RTC alarm time.
+ */
+static int twl_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ unsigned char rtc_data[ALL_TIME_REGS];
+ int ret;
+
+ ret = twl_i2c_read(TWL_MODULE_RTC, rtc_data,
+ (rtc_reg_map[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 twl_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ unsigned char alarm_data[ALL_TIME_REGS];
+ int ret;
+
+ ret = twl_rtc_alarm_irq_enable(dev, 0);
+ if (ret)
+ goto out;
+
+ alarm_data[0] = bin2bcd(alm->time.tm_sec);
+ alarm_data[1] = bin2bcd(alm->time.tm_min);
+ alarm_data[2] = bin2bcd(alm->time.tm_hour);
+ alarm_data[3] = bin2bcd(alm->time.tm_mday);
+ alarm_data[4] = bin2bcd(alm->time.tm_mon + 1);
+ alarm_data[5] = bin2bcd(alm->time.tm_year - 100);
+
+ /* update all the alarm registers in one shot */
+ ret = twl_i2c_write(TWL_MODULE_RTC, alarm_data,
+ (rtc_reg_map[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 = twl_rtc_alarm_irq_enable(dev, 1);
+out:
+ return ret;
+}
+
+static irqreturn_t twl_rtc_interrupt(int irq, void *rtc)
+{
+ unsigned long events;
+ int ret = IRQ_NONE;
+ int res;
+ u8 rd_reg;
+
+ res = twl_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_PF;
+
+ res = twl_rtc_write_u8(BIT_RTC_STATUS_REG_ALARM_M,
+ REG_RTC_STATUS_REG);
+ if (res)
+ goto out;
+
+ if (twl_class_is_4030()) {
+ /* 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_twl_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 = twl_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 twl_rtc_ops = {
+ .read_time = twl_rtc_read_time,
+ .set_time = twl_rtc_set_time,
+ .read_alarm = twl_rtc_read_alarm,
+ .set_alarm = twl_rtc_set_alarm,
+ .alarm_irq_enable = twl_rtc_alarm_irq_enable,
+};
+
+/*----------------------------------------------------------------------*/
+
+static int twl_rtc_probe(struct platform_device *pdev)
+{
+ struct rtc_device *rtc;
+ int ret = -EINVAL;
+ int irq = platform_get_irq(pdev, 0);
+ u8 rd_reg;
+
+ if (irq <= 0)
+ return ret;
+
+ /* Initialize the register map */
+ if (twl_class_is_4030())
+ rtc_reg_map = (u8 *)twl4030_rtc_reg_map;
+ else
+ rtc_reg_map = (u8 *)twl6030_rtc_reg_map;
+
+ ret = twl_rtc_read_u8(&rd_reg, REG_RTC_STATUS_REG);
+ if (ret < 0)
+ return ret;
+
+ 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 = twl_rtc_write_u8(rd_reg, REG_RTC_STATUS_REG);
+ if (ret < 0)
+ return ret;
+
+ if (twl_class_is_6030()) {
+ twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
+ REG_INT_MSK_LINE_A);
+ twl6030_interrupt_unmask(TWL6030_RTC_INT_MASK,
+ REG_INT_MSK_STS_A);
+ }
+
+ dev_info(&pdev->dev, "Enabling TWL-RTC\n");
+ ret = twl_rtc_write_u8(BIT_RTC_CTRL_REG_STOP_RTC_M, REG_RTC_CTRL_REG);
+ if (ret < 0)
+ return ret;
+
+ /* ensure interrupts are disabled, bootloaders can be strange */
+ ret = twl_rtc_write_u8(0, REG_RTC_INTERRUPTS_REG);
+ if (ret < 0)
+ dev_warn(&pdev->dev, "unable to disable interrupt\n");
+
+ /* init cached IRQ enable bits */
+ ret = twl_rtc_read_u8(&rtc_irq_bits, REG_RTC_INTERRUPTS_REG);
+ if (ret < 0)
+ return ret;
+
+ device_init_wakeup(&pdev->dev, 1);
+
+ rtc = devm_rtc_device_register(&pdev->dev, pdev->name,
+ &twl_rtc_ops, THIS_MODULE);
+ if (IS_ERR(rtc)) {
+ dev_err(&pdev->dev, "can't register RTC device, err %ld\n",
+ PTR_ERR(rtc));
+ return PTR_ERR(rtc);
+ }
+
+ ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
+ twl_rtc_interrupt,
+ IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+ dev_name(&rtc->dev), rtc);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "IRQ is not free.\n");
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, rtc);
+ return 0;
+}
+
+/*
+ * Disable all TWL RTC module interrupts.
+ * Sets status flag to free.
+ */
+static int twl_rtc_remove(struct platform_device *pdev)
+{
+ /* leave rtc running, but disable irqs */
+ mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
+ mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+ if (twl_class_is_6030()) {
+ twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
+ REG_INT_MSK_LINE_A);
+ twl6030_interrupt_mask(TWL6030_RTC_INT_MASK,
+ REG_INT_MSK_STS_A);
+ }
+
+ return 0;
+}
+
+static void twl_rtc_shutdown(struct platform_device *pdev)
+{
+ /* mask timer interrupts, but leave alarm interrupts on to enable
+ power-on when alarm is triggered */
+ mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+}
+
+#ifdef CONFIG_PM_SLEEP
+static unsigned char irqstat;
+
+static int twl_rtc_suspend(struct device *dev)
+{
+ irqstat = rtc_irq_bits;
+
+ mask_rtc_irq_bit(BIT_RTC_INTERRUPTS_REG_IT_TIMER_M);
+ return 0;
+}
+
+static int twl_rtc_resume(struct device *dev)
+{
+ set_rtc_irq_bit(irqstat);
+ return 0;
+}
+#endif
+
+static SIMPLE_DEV_PM_OPS(twl_rtc_pm_ops, twl_rtc_suspend, twl_rtc_resume);
+
+#ifdef CONFIG_OF
+static const struct of_device_id twl_rtc_of_match[] = {
+ {.compatible = "ti,twl4030-rtc", },
+ { },
+};
+MODULE_DEVICE_TABLE(of, twl_rtc_of_match);
+#endif
+
+MODULE_ALIAS("platform:twl_rtc");
+
+static struct platform_driver twl4030rtc_driver = {
+ .probe = twl_rtc_probe,
+ .remove = twl_rtc_remove,
+ .shutdown = twl_rtc_shutdown,
+ .driver = {
+ .name = "twl_rtc",
+ .pm = &twl_rtc_pm_ops,
+ .of_match_table = of_match_ptr(twl_rtc_of_match),
+ },
+};
+
+module_platform_driver(twl4030rtc_driver);
+
+MODULE_AUTHOR("Texas Instruments, MontaVista Software");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff