lkml.org 
[lkml]   [2016]   [Jun]   [15]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH v2 04/10] rtc: ac100: Add RTC driver for X-Powers AC100
    Date
    X-Powers AC100 is a codec / RTC combo chip. This driver supports
    the RTC sub-device.

    The RTC block also has clock outputs and non-volatile storage.
    Non-volatile storage wthin the RTC hardware is not supported.
    Clock output support is added in the next patch.

    Signed-off-by: Chen-Yu Tsai <wens@csie.org>
    ---
    drivers/rtc/Kconfig | 10 ++
    drivers/rtc/Makefile | 1 +
    drivers/rtc/rtc-ac100.c | 367 ++++++++++++++++++++++++++++++++++++++++++++++++
    3 files changed, 378 insertions(+)
    create mode 100644 drivers/rtc/rtc-ac100.c

    diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
    index 18639e0cb6e2..b9d7cbb6bd76 100644
    --- a/drivers/rtc/Kconfig
    +++ b/drivers/rtc/Kconfig
    @@ -183,6 +183,16 @@ config RTC_DRV_ABX80X
    This driver can also be built as a module. If so, the module
    will be called rtc-abx80x.

    +config RTC_DRV_AC100
    + tristate "X-Powers AC100"
    + depends on MFD_AC100
    + help
    + If you say yes here you get support for the real-time clock found
    + in X-Powers AC100 family peripheral ICs.
    +
    + This driver can also be built as a module. If so, the module
    + will be called rtc-ac100.
    +
    config RTC_DRV_AS3722
    tristate "ams AS3722 RTC driver"
    depends on MFD_AS3722
    diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
    index ea2833723fa9..b07c28779573 100644
    --- a/drivers/rtc/Makefile
    +++ b/drivers/rtc/Makefile
    @@ -26,6 +26,7 @@ obj-$(CONFIG_RTC_DRV_AB3100) += rtc-ab3100.o
    obj-$(CONFIG_RTC_DRV_AB8500) += rtc-ab8500.o
    obj-$(CONFIG_RTC_DRV_ABB5ZES3) += rtc-ab-b5ze-s3.o
    obj-$(CONFIG_RTC_DRV_ABX80X) += rtc-abx80x.o
    +obj-$(CONFIG_RTC_DRV_AC100) += rtc-ac100.o
    obj-$(CONFIG_RTC_DRV_ARMADA38X) += rtc-armada38x.o
    obj-$(CONFIG_RTC_DRV_AS3722) += rtc-as3722.o
    obj-$(CONFIG_RTC_DRV_ASM9260) += rtc-asm9260.o
    diff --git a/drivers/rtc/rtc-ac100.c b/drivers/rtc/rtc-ac100.c
    new file mode 100644
    index 000000000000..360346792ca5
    --- /dev/null
    +++ b/drivers/rtc/rtc-ac100.c
    @@ -0,0 +1,367 @@
    +/*
    + * RTC Driver for X-Powers AC100
    + *
    + * Copyright (c) 2015, Chen-Yu Tsai <wens@csie.org>
    + *
    + * 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.
    + *
    + * This program is distributed in the hope that 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/bcd.h>
    +#include <linux/device.h>
    +#include <linux/interrupt.h>
    +#include <linux/kernel.h>
    +#include <linux/mfd/ac100.h>
    +#include <linux/module.h>
    +#include <linux/mutex.h>
    +#include <linux/of.h>
    +#include <linux/of_irq.h>
    +#include <linux/platform_device.h>
    +#include <linux/regmap.h>
    +#include <linux/rtc.h>
    +#include <linux/types.h>
    +
    +/* Control register */
    +#define AC100_RTC_CTRL_24HOUR BIT(0)
    +
    +/* RTC */
    +#define AC100_RTC_SEC_MASK GENMASK(6, 0)
    +#define AC100_RTC_MIN_MASK GENMASK(6, 0)
    +#define AC100_RTC_HOU_MASK GENMASK(5, 0)
    +#define AC100_RTC_WEE_MASK GENMASK(3, 0)
    +#define AC100_RTC_DAY_MASK GENMASK(5, 0)
    +#define AC100_RTC_MON_MASK GENMASK(4, 0)
    +#define AC100_RTC_YEA_MASK GENMASK(7, 0)
    +#define AC100_RTC_YEA_LEAP BIT(15)
    +#define AC100_RTC_UPD_TRIGGER BIT(15)
    +
    +/* Alarm (wall clock) */
    +#define AC100_ALM_INT_ENABLE BIT(0)
    +
    +#define AC100_ALM_SEC_MASK GENMASK(5, 0)
    +#define AC100_ALM_MIN_MASK GENMASK(5, 0)
    +#define AC100_ALM_HOU_MASK GENMASK(4, 0)
    +#define AC100_ALM_WEE_MASK GENMASK(3, 0)
    +#define AC100_ALM_DAY_MASK GENMASK(5, 0)
    +#define AC100_ALM_MON_MASK GENMASK(4, 0)
    +#define AC100_ALM_YEA_MASK GENMASK(7, 0)
    +#define AC100_ALM_ENABLE_FLAG BIT(15)
    +#define AC100_ALM_UPD_TRIGGER BIT(15)
    +
    +/*
    + * The year parameter passed to the driver is usually an offset relative to
    + * the year 1900. This macro is used to convert this offset to another one
    + * relative to the minimum year allowed by the hardware.
    + *
    + * The year range is 1970 - 2069. This range is selected to match Allwinner's
    + * driver.
    + */
    +#define AC100_YEAR_MIN 1970
    +#define AC100_YEAR_MAX 2069
    +#define AC100_YEAR_OFF (AC100_YEAR_MIN - 1900)
    +
    +struct ac100_rtc_dev {
    + struct rtc_device *rtc;
    + struct device *dev;
    + struct regmap *regmap;
    + struct mutex mutex;
    + int irq;
    + unsigned long alarm;
    +};
    +
    +static int ac100_rtc_get_time(struct device *dev, struct rtc_time *rtc_tm)
    +{
    + struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
    + struct regmap *regmap = chip->regmap;
    + u16 reg[7];
    + int ret;
    +
    + ret = regmap_bulk_read(regmap, AC100_RTC_SEC, reg, 7);
    + if (ret)
    + return ret;
    +
    + rtc_tm->tm_sec = bcd2bin(reg[0] & AC100_RTC_SEC_MASK);
    + rtc_tm->tm_min = bcd2bin(reg[1] & AC100_RTC_MIN_MASK);
    + rtc_tm->tm_hour = bcd2bin(reg[2] & AC100_RTC_HOU_MASK);
    + rtc_tm->tm_wday = bcd2bin(reg[3] & AC100_RTC_WEE_MASK);
    + rtc_tm->tm_mday = bcd2bin(reg[4] & AC100_RTC_DAY_MASK);
    + rtc_tm->tm_mon = bcd2bin(reg[5] & AC100_RTC_MON_MASK);
    + rtc_tm->tm_year = bcd2bin(reg[6] & AC100_RTC_YEA_MASK);
    +
    + rtc_tm->tm_mon -= 1;
    +
    + /*
    + * switch from (data_year->min)-relative offset to
    + * a (1900)-relative one
    + */
    + rtc_tm->tm_year += AC100_YEAR_OFF;
    +
    + return rtc_valid_tm(rtc_tm);
    +}
    +
    +static int ac100_rtc_set_time(struct device *dev, struct rtc_time *rtc_tm)
    +{
    + struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
    + struct regmap *regmap = chip->regmap;
    + int year;
    + u16 reg[8];
    +
    + /* our RTC has a limited year range... */
    + year = rtc_tm->tm_year + 1900;
    + if (year < AC100_YEAR_MIN || year > AC100_YEAR_MAX) {
    + dev_err(dev, "rtc only supports year in range %d - %d\n",
    + AC100_YEAR_MIN, AC100_YEAR_MAX);
    + return -EINVAL;
    + }
    +
    + /* correct offsets */
    + rtc_tm->tm_year -= AC100_YEAR_OFF;
    + rtc_tm->tm_mon += 1;
    +
    + /* convert to BCD */
    + reg[0] = bin2bcd(rtc_tm->tm_sec) & AC100_RTC_SEC_MASK;
    + reg[1] = bin2bcd(rtc_tm->tm_min) & AC100_RTC_MIN_MASK;
    + reg[2] = bin2bcd(rtc_tm->tm_hour) & AC100_RTC_HOU_MASK;
    + reg[3] = bin2bcd(rtc_tm->tm_wday) & AC100_RTC_WEE_MASK;
    + reg[4] = bin2bcd(rtc_tm->tm_mday) & AC100_RTC_DAY_MASK;
    + reg[5] = bin2bcd(rtc_tm->tm_mon) & AC100_RTC_MON_MASK;
    + reg[6] = bin2bcd(rtc_tm->tm_year) & AC100_RTC_YEA_MASK;
    + /* trigger write */
    + reg[7] = AC100_RTC_UPD_TRIGGER;
    +
    + /* Is it a leap year? */
    + if (is_leap_year(year))
    + reg[6] |= AC100_RTC_YEA_LEAP;
    +
    + return regmap_bulk_write(regmap, AC100_RTC_SEC, reg, 8);
    +}
    +
    +static int _ac100_rtc_alarm_irq_enable(struct ac100_rtc_dev *chip,
    + unsigned int en)
    +{
    + struct regmap *regmap = chip->regmap;
    + unsigned int val;
    +
    + val = en ? AC100_ALM_INT_ENABLE : 0;
    +
    + return regmap_write(regmap, AC100_ALM_INT_ENA, val);
    +}
    +
    +static int ac100_rtc_alarm_irq_enable(struct device *dev, unsigned int en)
    +{
    + struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
    + int ret;
    +
    + mutex_lock(&chip->mutex);
    + ret = _ac100_rtc_alarm_irq_enable(chip, en);
    + mutex_unlock(&chip->mutex);
    +
    + return ret;
    +}
    +
    +static int ac100_rtc_get_alarm(struct device *dev, struct rtc_wkalrm *alrm)
    +{
    + struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
    + struct regmap *regmap = chip->regmap;
    + struct rtc_time *alrm_tm = &alrm->time;
    + u16 reg[7];
    + unsigned int val;
    + int ret;
    +
    + mutex_lock(&chip->mutex);
    +
    + ret = regmap_read(regmap, AC100_ALM_INT_ENA, &val);
    + if (ret)
    + goto out;
    +
    + alrm->enabled = !!(val & AC100_ALM_INT_ENABLE);
    +
    + ret = regmap_bulk_read(regmap, AC100_ALM_SEC, reg, 7);
    + if (ret)
    + goto out;
    +
    + alrm_tm->tm_sec = bcd2bin(reg[0] & AC100_ALM_SEC_MASK);
    + alrm_tm->tm_min = bcd2bin(reg[1] & AC100_ALM_MIN_MASK);
    + alrm_tm->tm_hour = bcd2bin(reg[2] & AC100_ALM_HOU_MASK);
    + alrm_tm->tm_wday = bcd2bin(reg[3] & AC100_ALM_WEE_MASK);
    + alrm_tm->tm_mday = bcd2bin(reg[4] & AC100_ALM_DAY_MASK);
    + alrm_tm->tm_mon = bcd2bin(reg[5] & AC100_ALM_MON_MASK);
    + alrm_tm->tm_year = bcd2bin(reg[6] & AC100_ALM_YEA_MASK);
    +
    + alrm_tm->tm_mon -= 1;
    +
    + /*
    + * switch from (data_year->min)-relative offset to
    + * a (1900)-relative one
    + */
    + alrm_tm->tm_year += AC100_YEAR_OFF;
    +
    +out:
    + mutex_unlock(&chip->mutex);
    + return ret;
    +}
    +
    +static int ac100_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)
    +{
    + struct ac100_rtc_dev *chip = dev_get_drvdata(dev);
    + struct regmap *regmap = chip->regmap;
    + struct rtc_time *alrm_tm = &alrm->time;
    + u16 reg[8];
    + int year;
    + int ret;
    +
    + /* our alarm has a limited year range... */
    + year = alrm_tm->tm_year + 1900;
    + if (year < AC100_YEAR_MIN || year > AC100_YEAR_MAX) {
    + dev_err(dev, "alarm only supports year in range %d - %d\n",
    + AC100_YEAR_MIN, AC100_YEAR_MAX);
    + return -EINVAL;
    + }
    +
    + /* correct offsets */
    + alrm_tm->tm_year -= AC100_YEAR_OFF;
    + alrm_tm->tm_mon += 1;
    +
    + /* convert to BCD */
    + reg[0] = (bin2bcd(alrm_tm->tm_sec) & AC100_RTC_SEC_MASK) |
    + AC100_ALM_ENABLE_FLAG;
    + reg[1] = (bin2bcd(alrm_tm->tm_min) & AC100_RTC_MIN_MASK) |
    + AC100_ALM_ENABLE_FLAG;
    + reg[2] = (bin2bcd(alrm_tm->tm_hour) & AC100_RTC_HOU_MASK) |
    + AC100_ALM_ENABLE_FLAG;
    + /* Do not enable weekday alarm */
    + reg[3] = bin2bcd(alrm_tm->tm_wday) & AC100_RTC_WEE_MASK;
    + reg[4] = (bin2bcd(alrm_tm->tm_mday) & AC100_RTC_DAY_MASK) |
    + AC100_ALM_ENABLE_FLAG;
    + reg[5] = (bin2bcd(alrm_tm->tm_mon) & AC100_RTC_MON_MASK) |
    + AC100_ALM_ENABLE_FLAG;
    + reg[6] = (bin2bcd(alrm_tm->tm_year) & AC100_RTC_YEA_MASK) |
    + AC100_ALM_ENABLE_FLAG;
    + /* trigger write */
    + reg[7] = AC100_RTC_UPD_TRIGGER;
    +
    + mutex_lock(&chip->mutex);
    +
    + ret = regmap_bulk_write(regmap, AC100_RTC_SEC, reg, 8);
    + if (ret)
    + goto out;
    +
    + ret = _ac100_rtc_alarm_irq_enable(chip, alrm->enabled);
    +
    +out:
    + mutex_unlock(&chip->mutex);
    + return ret;
    +}
    +
    +static irqreturn_t ac100_rtc_irq(int irq, void *data)
    +{
    + struct ac100_rtc_dev *chip = data;
    + struct regmap *regmap = chip->regmap;
    + unsigned int val = 0;
    + int ret;
    +
    + mutex_lock(&chip->mutex);
    +
    + /* read status */
    + ret = regmap_read(regmap, AC100_ALM_INT_STA, &val);
    + if (ret)
    + goto out;
    +
    + if (val & AC100_ALM_INT_ENABLE) {
    + /* signal rtc framework */
    + rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF);
    +
    + /* clear status */
    + ret = regmap_write(regmap, AC100_ALM_INT_STA, val);
    + if (ret)
    + goto out;
    +
    + /* disable interrupt */
    + ret = _ac100_rtc_alarm_irq_enable(chip, 0);
    + if (ret)
    + goto out;
    + }
    +
    +out:
    + mutex_unlock(&chip->mutex);
    + return IRQ_HANDLED;
    +}
    +
    +static const struct rtc_class_ops ac100_rtc_ops = {
    + .read_time = ac100_rtc_get_time,
    + .set_time = ac100_rtc_set_time,
    + .read_alarm = ac100_rtc_get_alarm,
    + .set_alarm = ac100_rtc_set_alarm,
    + .alarm_irq_enable = ac100_rtc_alarm_irq_enable,
    +};
    +
    +static int ac100_rtc_probe(struct platform_device *pdev)
    +{
    + struct ac100_dev *ac100 = dev_get_drvdata(pdev->dev.parent);
    + struct ac100_rtc_dev *chip;
    + int ret;
    +
    + chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL);
    + platform_set_drvdata(pdev, chip);
    + chip->dev = &pdev->dev;
    + chip->regmap = ac100->regmap;
    + mutex_init(&chip->mutex);
    +
    + chip->irq = of_irq_get(pdev->dev.of_node, 0);
    + if (chip->irq < 0) {
    + dev_err(&pdev->dev, "No IRQ resource\n");
    + return chip->irq;
    + }
    +
    + ret = devm_request_threaded_irq(&pdev->dev, chip->irq, NULL,
    + ac100_rtc_irq,
    + IRQF_SHARED | IRQF_ONESHOT,
    + dev_name(&pdev->dev), chip);
    + if (ret) {
    + dev_err(&pdev->dev, "Could not request IRQ\n");
    + return ret;
    + }
    +
    + /* always use 24 hour mode */
    + regmap_write_bits(chip->regmap, AC100_RTC_CTRL, AC100_RTC_CTRL_24HOUR,
    + AC100_RTC_CTRL_24HOUR);
    +
    + /* disable counter alarm interrupt */
    + regmap_write(chip->regmap, AC100_ALM_INT_ENA, 0);
    +
    + /* clear counter alarm pending interrupts */
    + regmap_write(chip->regmap, AC100_ALM_INT_STA, AC100_ALM_INT_ENABLE);
    +
    + chip->rtc = devm_rtc_device_register(&pdev->dev, "rtc-ac100",
    + &ac100_rtc_ops, THIS_MODULE);
    + if (IS_ERR(chip->rtc)) {
    + dev_err(&pdev->dev, "unable to register device\n");
    + return PTR_ERR(chip->rtc);
    + }
    +
    + /* We do not support user interrupts */
    + chip->rtc->uie_unsupported = 1;
    +
    + dev_info(&pdev->dev, "RTC enabled\n");
    +
    + return 0;
    +}
    +
    +static struct platform_driver ac100_rtc_driver = {
    + .probe = ac100_rtc_probe,
    + .driver = {
    + .name = "ac100-rtc",
    + },
    +};
    +module_platform_driver(ac100_rtc_driver);
    +
    +MODULE_DESCRIPTION("X-Powers AC100 RTC driver");
    +MODULE_AUTHOR("Chen-Yu Tsai <wens@csie.org>");
    +MODULE_LICENSE("GPL");
    --
    2.8.1
    \
     
     \ /
      Last update: 2016-06-15 13:21    [W:2.339 / U:0.008 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site