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    Subject[PATCH v8 3/5] RTC: RK808: add RTC driver for RK808
    Date
    Adding RTC driver for supporting RTC device present inside RK808 PMIC.

    Signed-off-by: Chris Zhong <zyw@rock-chips.com>
    Signed-off-by: Zhang Qing <zhangqing@rock-chips.com>

    Tested-by: Heiko <heiko@sntech.de>
    ---

    Changes in v8:
    Adviced by Doug
    - coding style
    - fix regmap_update_bits()
    - if(rk808_rtc->irq < 0) return err num

    Changes in v7:
    Adviced by doug
    - read rtc time from shadowed registers
    Adviced by Dmitry
    - use CONFIG_PM_SLEEP replace CONFIG_PM
    - use SIMPLE_DEV_PM_OPS replace dev_pm_ops
    - fix dev_warn
    - coding style
    Adviced by Heiko
    - remove rtc_ctl

    Changes in v6:
    Adviced by doug
    - move RTC_READSEL setting into probe

    Changes in v5:
    - fixed a bug about set_time failed

    Changes in v4:
    - use &client->dev replace rk808->dev

    Changes in v3: None
    Changes in v2:
    Adviced by javier.martinez
    - Add a separate clock driver, rather than in RTC driver

    drivers/rtc/Kconfig | 10 ++
    drivers/rtc/Makefile | 1 +
    drivers/rtc/rtc-rk808.c | 426 +++++++++++++++++++++++++++++++++++++++++++++++
    3 files changed, 437 insertions(+)
    create mode 100644 drivers/rtc/rtc-rk808.c

    diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
    index a168e96..aeab9d9 100644
    --- a/drivers/rtc/Kconfig
    +++ b/drivers/rtc/Kconfig
    @@ -288,6 +288,16 @@ config RTC_DRV_MAX77686
    This driver can also be built as a module. If so, the module
    will be called rtc-max77686.

    +config RTC_DRV_RK808
    + tristate "Rockchip RK808 RTC"
    + depends on MFD_RK808
    + help
    + If you say yes here you will get support for the
    + RTC of RK808 PMIC.
    +
    + This driver can also be built as a module. If so, the module
    + will be called rk808-rtc.
    +
    config RTC_DRV_RS5C372
    tristate "Ricoh R2025S/D, RS5C372A/B, RV5C386, RV5C387A"
    help
    diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
    index 56f061c..91fe4647 100644
    --- a/drivers/rtc/Makefile
    +++ b/drivers/rtc/Makefile
    @@ -109,6 +109,7 @@ obj-$(CONFIG_RTC_DRV_PUV3) += rtc-puv3.o
    obj-$(CONFIG_RTC_DRV_PXA) += rtc-pxa.o
    obj-$(CONFIG_RTC_DRV_R9701) += rtc-r9701.o
    obj-$(CONFIG_RTC_DRV_RC5T583) += rtc-rc5t583.o
    +obj-$(CONFIG_RTC_DRV_RK808) += rtc-rk808.o
    obj-$(CONFIG_RTC_DRV_RP5C01) += rtc-rp5c01.o
    obj-$(CONFIG_RTC_DRV_RS5C313) += rtc-rs5c313.o
    obj-$(CONFIG_RTC_DRV_RS5C348) += rtc-rs5c348.o
    diff --git a/drivers/rtc/rtc-rk808.c b/drivers/rtc/rtc-rk808.c
    new file mode 100644
    index 0000000..8ef08088
    --- /dev/null
    +++ b/drivers/rtc/rtc-rk808.c
    @@ -0,0 +1,426 @@
    +/*
    + * RTC driver for Rockchip RK808
    + *
    + * Copyright (c) 2014, Fuzhou Rockchip Electronics Co., Ltd
    + *
    + * Author: Chris Zhong <zyw@rock-chips.com>
    + * Author: Zhang Qing <zhanqging@rock-chips.com>
    + *
    + * This program is free software; you can redistribute it and/or modify it
    + * under the terms and conditions of the GNU General Public License,
    + * version 2, as published by the Free Software Foundation.
    + *
    + * This program is distributed in the hope it will be useful, but WITHOUT
    + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
    + * more details.
    + */
    +
    +#include <linux/module.h>
    +#include <linux/kernel.h>
    +#include <linux/rtc.h>
    +#include <linux/bcd.h>
    +#include <linux/mfd/rk808.h>
    +#include <linux/platform_device.h>
    +#include <linux/i2c.h>
    +
    +/* RTC_CTRL_REG bitfields */
    +#define BIT_RTC_CTRL_REG_STOP_RTC_M BIT(0)
    +
    +/* RK808 has a shadowed register for saving a "frozen" RTC time.
    + * When user setting "GET_TIME" to 1, the time will save in this shadowed
    + * register. If set "READSEL" to 1, user read rtc time register, actually
    + * get the time of that moment. If we need the real time, clr this bit.
    + */
    +#define BIT_RTC_CTRL_REG_RTC_GET_TIME BIT(6)
    +#define BIT_RTC_CTRL_REG_RTC_READSEL_M BIT(7)
    +#define BIT_RTC_INTERRUPTS_REG_IT_ALARM_M BIT(3)
    +#define RTC_STATUS_MASK 0xFE
    +
    +#define SECONDS_REG_MSK 0x7F
    +#define MINUTES_REG_MAK 0x7F
    +#define HOURS_REG_MSK 0x3F
    +#define DAYS_REG_MSK 0x3F
    +#define MONTHS_REG_MSK 0x1F
    +#define YEARS_REG_MSK 0xFF
    +#define WEEKS_REG_MSK 0x7
    +
    +/* REG_SECONDS_REG through REG_YEARS_REG is how many registers? */
    +
    +#define NUM_TIME_REGS (RK808_WEEKS_REG - RK808_SECONDS_REG + 1)
    +#define NUM_ALARM_REGS (RK808_ALARM_YEARS_REG - RK808_ALARM_SECONDS_REG + 1)
    +
    +struct rk808_rtc {
    + struct rk808 *rk808;
    + struct rtc_device *rtc;
    + int irq;
    +};
    +
    +/* Read current time and date in RTC */
    +static int rk808_rtc_readtime(struct device *dev, struct rtc_time *tm)
    +{
    + struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
    + struct rk808 *rk808 = rk808_rtc->rk808;
    + u8 rtc_data[NUM_TIME_REGS];
    + int ret;
    +
    + /* Force an update of the shadowed registers right now */
    + ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
    + BIT_RTC_CTRL_REG_RTC_GET_TIME,
    + 0);
    + if (ret) {
    + dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
    + return ret;
    + }
    +
    + ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
    + BIT_RTC_CTRL_REG_RTC_GET_TIME,
    + BIT_RTC_CTRL_REG_RTC_GET_TIME);
    + if (ret) {
    + dev_err(dev, "Failed to update bits rtc_ctrl: %d\n", ret);
    + return ret;
    + }
    +
    + ret = regmap_bulk_read(rk808->regmap, RK808_SECONDS_REG,
    + rtc_data, NUM_TIME_REGS);
    + if (ret) {
    + dev_err(dev, "Failed to bulk read rtc_data: %d\n", ret);
    + return ret;
    + }
    +
    + tm->tm_sec = bcd2bin(rtc_data[0] & SECONDS_REG_MSK);
    + tm->tm_min = bcd2bin(rtc_data[1] & MINUTES_REG_MAK);
    + tm->tm_hour = bcd2bin(rtc_data[2] & HOURS_REG_MSK);
    + tm->tm_mday = bcd2bin(rtc_data[3] & DAYS_REG_MSK);
    + tm->tm_mon = (bcd2bin(rtc_data[4] & MONTHS_REG_MSK)) - 1;
    + tm->tm_year = (bcd2bin(rtc_data[5] & YEARS_REG_MSK)) + 100;
    + tm->tm_wday = bcd2bin(rtc_data[6] & WEEKS_REG_MSK);
    + dev_dbg(dev, "RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
    + 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
    + tm->tm_wday, tm->tm_hour , tm->tm_min, tm->tm_sec);
    +
    + return ret;
    +}
    +
    +/* Set current time and date in RTC */
    +static int rk808_rtc_set_time(struct device *dev, struct rtc_time *tm)
    +{
    + struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
    + struct rk808 *rk808 = rk808_rtc->rk808;
    + u8 rtc_data[NUM_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);
    + rtc_data[6] = bin2bcd(tm->tm_wday);
    + dev_dbg(dev, "set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
    + 1900 + tm->tm_year, tm->tm_mon + 1, tm->tm_mday,
    + tm->tm_wday, tm->tm_hour , tm->tm_min, tm->tm_sec);
    +
    + /* Stop RTC while updating the RTC registers */
    + ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
    + BIT_RTC_CTRL_REG_STOP_RTC_M,
    + BIT_RTC_CTRL_REG_STOP_RTC_M);
    + if (ret) {
    + dev_err(dev, "Failed to update RTC control: %d\n", ret);
    + return ret;
    + }
    +
    + ret = regmap_bulk_write(rk808->regmap, RK808_SECONDS_REG,
    + rtc_data, NUM_TIME_REGS);
    + if (ret) {
    + dev_err(dev, "Failed to bull write rtc_data: %d\n", ret);
    + return ret;
    + }
    + /* Start RTC again */
    + ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
    + BIT_RTC_CTRL_REG_STOP_RTC_M, 0);
    + if (ret) {
    + dev_err(dev, "Failed to update RTC control: %d\n", ret);
    + return ret;
    + }
    + return 0;
    +}
    +
    +/* Read alarm time and date in RTC */
    +static int rk808_rtc_readalarm(struct device *dev, struct rtc_wkalrm *alrm)
    +{
    + struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
    + struct rk808 *rk808 = rk808_rtc->rk808;
    + u8 alrm_data[NUM_ALARM_REGS];
    + uint32_t int_reg;
    + int ret;
    +
    + ret = regmap_bulk_read(rk808->regmap, RK808_ALARM_SECONDS_REG,
    + alrm_data, NUM_ALARM_REGS);
    +
    + alrm->time.tm_sec = bcd2bin(alrm_data[0] & SECONDS_REG_MSK);
    + alrm->time.tm_min = bcd2bin(alrm_data[1] & MINUTES_REG_MAK);
    + alrm->time.tm_hour = bcd2bin(alrm_data[2] & HOURS_REG_MSK);
    + alrm->time.tm_mday = bcd2bin(alrm_data[3] & DAYS_REG_MSK);
    + alrm->time.tm_mon = (bcd2bin(alrm_data[4] & MONTHS_REG_MSK)) - 1;
    + alrm->time.tm_year = (bcd2bin(alrm_data[5] & YEARS_REG_MSK)) + 100;
    +
    + ret = regmap_read(rk808->regmap, RK808_RTC_INT_REG, &int_reg);
    + if (ret) {
    + dev_err(dev, "Failed to read RTC INT REG: %d\n", ret);
    + return ret;
    + }
    +
    + dev_dbg(dev, "alrm read RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
    + 1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
    + alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
    + alrm->time.tm_min, alrm->time.tm_sec);
    +
    + alrm->enabled = (int_reg & BIT_RTC_INTERRUPTS_REG_IT_ALARM_M) ? 1 : 0;
    +
    + return 0;
    +}
    +
    +static int rk808_rtc_stop_alarm(struct rk808_rtc *rk808_rtc)
    +{
    + struct rk808 *rk808 = rk808_rtc->rk808;
    + int ret;
    +
    + ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG,
    + BIT_RTC_INTERRUPTS_REG_IT_ALARM_M, 0);
    +
    + return ret;
    +}
    +
    +static int rk808_rtc_start_alarm(struct rk808_rtc *rk808_rtc)
    +{
    + struct rk808 *rk808 = rk808_rtc->rk808;
    + int ret;
    +
    + ret = regmap_update_bits(rk808->regmap, RK808_RTC_INT_REG,
    + BIT_RTC_INTERRUPTS_REG_IT_ALARM_M,
    + BIT_RTC_INTERRUPTS_REG_IT_ALARM_M);
    +
    + return ret;
    +}
    +
    +static int rk808_rtc_setalarm(struct device *dev, struct rtc_wkalrm *alrm)
    +{
    + struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
    + struct rk808 *rk808 = rk808_rtc->rk808;
    + u8 alrm_data[NUM_ALARM_REGS];
    + int ret;
    +
    + ret = rk808_rtc_stop_alarm(rk808_rtc);
    + if (ret) {
    + dev_err(dev, "Failed to stop alarm: %d\n", ret);
    + return ret;
    + }
    + dev_dbg(dev, "alrm set RTC date/time %4d-%02d-%02d(%d) %02d:%02d:%02d\n",
    + 1900 + alrm->time.tm_year, alrm->time.tm_mon + 1,
    + alrm->time.tm_mday, alrm->time.tm_wday, alrm->time.tm_hour,
    + alrm->time.tm_min, alrm->time.tm_sec);
    +
    + alrm_data[0] = bin2bcd(alrm->time.tm_sec);
    + alrm_data[1] = bin2bcd(alrm->time.tm_min);
    + alrm_data[2] = bin2bcd(alrm->time.tm_hour);
    + alrm_data[3] = bin2bcd(alrm->time.tm_mday);
    + alrm_data[4] = bin2bcd(alrm->time.tm_mon + 1);
    + alrm_data[5] = bin2bcd(alrm->time.tm_year - 100);
    +
    + ret = regmap_bulk_write(rk808->regmap, RK808_ALARM_SECONDS_REG,
    + alrm_data, NUM_ALARM_REGS);
    + if (ret) {
    + dev_err(dev, "Failed to bulk write: %d\n", ret);
    + return ret;
    + }
    + if (alrm->enabled) {
    + ret = rk808_rtc_start_alarm(rk808_rtc);
    + if (ret) {
    + dev_err(dev, "Failed to start alarm: %d\n", ret);
    + return ret;
    + }
    + }
    + return 0;
    +}
    +
    +static int rk808_rtc_alarm_irq_enable(struct device *dev,
    + unsigned int enabled)
    +{
    + struct rk808_rtc *rk808_rtc = dev_get_drvdata(dev);
    +
    + if (enabled)
    + return rk808_rtc_start_alarm(rk808_rtc);
    +
    + return rk808_rtc_stop_alarm(rk808_rtc);
    +}
    +
    +/*
    + * We will just handle setting the frequency and make use the framework for
    + * reading the periodic interupts.
    + *
    + * @freq: Current periodic IRQ freq:
    + * bit 0: every second
    + * bit 1: every minute
    + * bit 2: every hour
    + * bit 3: every day
    + */
    +static irqreturn_t rk808_alarm_irq(int irq, void *data)
    +{
    + struct rk808_rtc *rk808_rtc = data;
    + struct rk808 *rk808 = rk808_rtc->rk808;
    + struct i2c_client *client = rk808->i2c;
    + int ret;
    +
    + ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG,
    + RTC_STATUS_MASK);
    + if (ret) {
    + dev_err(&client->dev,
    + "%s:Failed to update RTC status: %d\n", __func__, ret);
    + return ret;
    + }
    +
    + rtc_update_irq(rk808_rtc->rtc, 1, RTC_IRQF | RTC_AF);
    + dev_dbg(&client->dev,
    + "%s:irq=%d\n", __func__, irq);
    + return IRQ_HANDLED;
    +}
    +
    +static const struct rtc_class_ops rk808_rtc_ops = {
    + .read_time = rk808_rtc_readtime,
    + .set_time = rk808_rtc_set_time,
    + .read_alarm = rk808_rtc_readalarm,
    + .set_alarm = rk808_rtc_setalarm,
    + .alarm_irq_enable = rk808_rtc_alarm_irq_enable,
    +};
    +
    +#ifdef CONFIG_PM_SLEEP
    +/* Turn off the alarm if it should not be a wake source. */
    +static int rk808_rtc_suspend(struct device *dev)
    +{
    + struct platform_device *pdev = to_platform_device(dev);
    + struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev);
    +
    + if (device_may_wakeup(dev))
    + enable_irq_wake(rk808_rtc->irq);
    +
    + return 0;
    +}
    +
    +/* Enable the alarm if it should be enabled (in case it was disabled to
    + * prevent use as a wake source).
    + */
    +static int rk808_rtc_resume(struct device *dev)
    +{
    + struct platform_device *pdev = to_platform_device(dev);
    + struct rk808_rtc *rk808_rtc = dev_get_drvdata(&pdev->dev);
    +
    + if (device_may_wakeup(dev))
    + disable_irq_wake(rk808_rtc->irq);
    +
    + return 0;
    +}
    +#endif
    +
    +static SIMPLE_DEV_PM_OPS(rk808_rtc_pm_ops,
    + rk808_rtc_suspend, rk808_rtc_resume);
    +
    +/* 2014.1.1 12:00:00 Saturday */
    +struct rtc_time tm_def = {
    + .tm_wday = 6,
    + .tm_year = 114,
    + .tm_mon = 0,
    + .tm_mday = 1,
    + .tm_hour = 12,
    + .tm_min = 0,
    + .tm_sec = 0,
    +};
    +
    +static int rk808_rtc_probe(struct platform_device *pdev)
    +{
    + struct rk808 *rk808 = dev_get_drvdata(pdev->dev.parent);
    + struct rk808_rtc *rk808_rtc;
    + struct rtc_time tm;
    + int ret;
    +
    + rk808_rtc = devm_kzalloc(&pdev->dev, sizeof(*rk808_rtc), GFP_KERNEL);
    + if (rk808_rtc == NULL)
    + return -ENOMEM;
    +
    + platform_set_drvdata(pdev, rk808_rtc);
    + rk808_rtc->rk808 = rk808;
    +
    + /* start rtc running by default, and use shadowed timer. */
    + ret = regmap_update_bits(rk808->regmap, RK808_RTC_CTRL_REG,
    + BIT_RTC_CTRL_REG_STOP_RTC_M |
    + BIT_RTC_CTRL_REG_RTC_READSEL_M,
    + BIT_RTC_CTRL_REG_RTC_READSEL_M);
    + if (ret) {
    + dev_err(&pdev->dev,
    + "Failed to update RTC control: %d\n", ret);
    + return ret;
    + }
    +
    + ret = regmap_write(rk808->regmap, RK808_RTC_STATUS_REG,
    + RTC_STATUS_MASK);
    + if (ret) {
    + dev_err(&pdev->dev,
    + "Failed to write RTC status: %d\n", ret);
    + return ret;
    + }
    +
    + /* set init time */
    + ret = rk808_rtc_readtime(&pdev->dev, &tm);
    + if (ret) {
    + dev_err(&pdev->dev, "Failed to read RTC time\n");
    + return ret;
    + }
    + ret = rtc_valid_tm(&tm);
    + if (ret) {
    + dev_warn(&pdev->dev, "invalid date/time and init time\n");
    + rk808_rtc_set_time(&pdev->dev, &tm_def);
    + }
    +
    + device_init_wakeup(&pdev->dev, 1);
    +
    + rk808_rtc->rtc = devm_rtc_device_register(&pdev->dev, "rk808-rtc",
    + &rk808_rtc_ops, THIS_MODULE);
    + if (IS_ERR(rk808_rtc->rtc)) {
    + ret = PTR_ERR(rk808_rtc->rtc);
    + return ret;
    + }
    +
    + rk808_rtc->irq = platform_get_irq(pdev, 0);
    + if (rk808_rtc->irq <= 0) {
    + dev_err(&pdev->dev, "Wake up is not possible as irq = %d\n",
    + rk808_rtc->irq);
    + return -ENXIO;
    + }
    +
    + /* request alarm irq of rk808 */
    + ret = devm_request_threaded_irq(&pdev->dev, rk808_rtc->irq, NULL,
    + rk808_alarm_irq, 0,
    + "RTC alarm", rk808_rtc);
    + if (ret) {
    + dev_err(&pdev->dev, "Failed to request alarm IRQ %d: %d\n",
    + rk808_rtc->irq, ret);
    + }
    +
    + return ret;
    +}
    +
    +static struct platform_driver rk808_rtc_driver = {
    + .probe = rk808_rtc_probe,
    + .driver = {
    + .name = "rk808-rtc",
    + .pm = &rk808_rtc_pm_ops,
    + },
    +};
    +
    +module_platform_driver(rk808_rtc_driver);
    +
    +MODULE_DESCRIPTION("RTC driver for the rk808 series PMICs");
    +MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
    +MODULE_AUTHOR("Zhang Qing <zhanqging@rock-chips.com>");
    +MODULE_LICENSE("GPL");
    +MODULE_ALIAS("platform:rk808-rtc");
    --
    1.7.9.5


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