[PATCH v4 2/3] rtc: mediatek: Add MT6397 RTC driver
Eddie Huang
eddie.huang at mediatek.com
Wed May 6 00:23:41 PDT 2015
From: Tianping Fang <tianping.fang at mediatek.com>
Add Mediatek MT6397 RTC driver
Signed-off-by: Tianping Fang <tianping.fang at mediatek.com>
Signed-off-by: Eddie Huang <eddie.huang at mediatek.com>
---
drivers/rtc/Kconfig | 10 ++
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-mt6397.c | 394 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 405 insertions(+)
create mode 100644 drivers/rtc/rtc-mt6397.c
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 6149ae0..9608fcb 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1520,6 +1520,16 @@ config RTC_DRV_MOXART
This driver can also be built as a module. If so, the module
will be called rtc-moxart
+config RTC_DRV_MT6397
+ tristate "Mediatek Real Time Clock driver"
+ depends on MFD_MT6397 || COMPILE_TEST
+ help
+ This selects the Mediatek(R) RTC driver. RTC is part of Mediatek
+ MT6397 PMIC. You should enable MT6397 PMIC MFD before select
+ Mediatek(R) RTC driver.
+
+ If you want to use Mediatek(R) RTC interface, select Y or M here.
+
config RTC_DRV_XGENE
tristate "APM X-Gene RTC"
depends on HAS_IOMEM
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index c31731c..6ba0ce2 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -154,3 +154,4 @@ obj-$(CONFIG_RTC_DRV_X1205) += rtc-x1205.o
obj-$(CONFIG_RTC_DRV_XGENE) += rtc-xgene.o
obj-$(CONFIG_RTC_DRV_SIRFSOC) += rtc-sirfsoc.o
obj-$(CONFIG_RTC_DRV_MOXART) += rtc-moxart.o
+obj-$(CONFIG_RTC_DRV_MT6397) += rtc-mt6397.o
diff --git a/drivers/rtc/rtc-mt6397.c b/drivers/rtc/rtc-mt6397.c
new file mode 100644
index 0000000..ca291a8
--- /dev/null
+++ b/drivers/rtc/rtc-mt6397.c
@@ -0,0 +1,394 @@
+/*
+* Copyright (c) 2014-2015 MediaTek Inc.
+* Author: Tianping.Fang <tianping.fang at mediatek.com>
+*
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License version 2 as
+* published by the Free Software Foundation.
+*
+* 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/delay.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/irqdomain.h>
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/io.h>
+#include <linux/mfd/mt6397/core.h>
+
+#define RTC_BBPU 0x0000
+#define RTC_BBPU_CBUSY BIT(6)
+
+#define RTC_WRTGR 0x003c
+
+#define RTC_IRQ_STA 0x0002
+#define RTC_IRQ_STA_AL BIT(0)
+#define RTC_IRQ_STA_LP BIT(3)
+
+#define RTC_IRQ_EN 0x0004
+#define RTC_IRQ_EN_AL BIT(0)
+#define RTC_IRQ_EN_ONESHOT BIT(2)
+#define RTC_IRQ_EN_LP BIT(3)
+#define RTC_IRQ_EN_ONESHOT_AL (RTC_IRQ_EN_ONESHOT | RTC_IRQ_EN_AL)
+
+#define RTC_AL_MASK 0x0008
+#define RTC_AL_MASK_DOW BIT(4)
+
+#define RTC_TC_SEC 0x000a
+/* Min, Hour, Dom... register offset to RTC_TC_SEC */
+#define RTC_OFFSET_SEC 0
+#define RTC_OFFSET_MIN 1
+#define RTC_OFFSET_HOUR 2
+#define RTC_OFFSET_DOM 3
+#define RTC_OFFSET_DOW 4
+#define RTC_OFFSET_MTH 5
+#define RTC_OFFSET_YEAR 6
+#define RTC_OFFSET_COUNT 7
+
+#define RTC_AL_SEC 0x0018
+
+#define RTC_PDN2 0x002e
+#define RTC_PDN2_PWRON_ALARM BIT(4)
+
+#define RTC_MIN_YEAR 1968
+#define RTC_BASE_YEAR 1900
+#define RTC_NUM_YEARS 128
+#define RTC_MIN_YEAR_OFFSET (RTC_MIN_YEAR - RTC_BASE_YEAR)
+
+struct mt6397_rtc {
+ struct device *dev;
+ struct rtc_device *rtc_dev;
+ struct mutex lock;
+ struct regmap *regmap;
+ int irq;
+ u32 addr_base;
+};
+
+static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc)
+{
+ unsigned long timeout = jiffies + HZ;
+ int ret;
+ u32 data;
+
+ ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_WRTGR, 1);
+ if (ret < 0)
+ return ret;
+
+ while (1) {
+ ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_BBPU,
+ &data);
+ if (ret < 0)
+ break;
+ if (!(data & RTC_BBPU_CBUSY))
+ break;
+ if (time_after(jiffies, timeout)) {
+ ret = -ETIMEDOUT;
+ break;
+ }
+ cpu_relax();
+ }
+
+ return ret;
+}
+
+static irqreturn_t mtk_rtc_irq_handler_thread(int irq, void *data)
+{
+ struct mt6397_rtc *rtc = data;
+ u32 irqsta, irqen;
+ int ret;
+
+ ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_STA, &irqsta);
+ if ((ret >= 0) && (irqsta & RTC_IRQ_STA_AL)) {
+ rtc_update_irq(rtc->rtc_dev, 1, RTC_IRQF | RTC_AF);
+ irqen = irqsta & ~RTC_IRQ_EN_AL;
+ mutex_lock(&rtc->lock);
+ if (regmap_write(rtc->regmap, rtc->addr_base + RTC_IRQ_EN,
+ irqen) < 0)
+ mtk_rtc_write_trigger(rtc);
+ mutex_unlock(&rtc->lock);
+
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
+}
+
+static int __mtk_rtc_read_time(struct mt6397_rtc *rtc,
+ struct rtc_time *tm, int *sec)
+{
+ int ret;
+ u16 data[RTC_OFFSET_COUNT];
+
+ mutex_lock(&rtc->lock);
+ ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC,
+ data, RTC_OFFSET_COUNT);
+ if (ret < 0)
+ goto exit;
+
+ tm->tm_sec = data[RTC_OFFSET_SEC];
+ tm->tm_min = data[RTC_OFFSET_MIN];
+ tm->tm_hour = data[RTC_OFFSET_HOUR];
+ tm->tm_mday = data[RTC_OFFSET_DOM];
+ tm->tm_mon = data[RTC_OFFSET_MTH];
+ tm->tm_year = data[RTC_OFFSET_YEAR];
+
+ ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_TC_SEC, sec);
+exit:
+ mutex_unlock(&rtc->lock);
+ return ret;
+}
+
+static int mtk_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ time64_t time;
+ struct mt6397_rtc *rtc = dev_get_drvdata(dev);
+ int sec, ret;
+
+ do {
+ ret = __mtk_rtc_read_time(rtc, tm, &sec);
+ if (ret < 0)
+ goto exit;
+ } while (sec < tm->tm_sec);
+
+ /* HW register use 7 bits to store year data, minus
+ * RTC_MIN_YEAR_OFFSET before write year data to register, and plus
+ * RTC_MIN_YEAR_OFFSET back after read year from register
+ */
+ tm->tm_year += RTC_MIN_YEAR_OFFSET;
+
+ /* HW register start mon from one, but tm_mon start from zero. */
+ tm->tm_mon--;
+ time = rtc_tm_to_time64(tm);
+
+ /* rtc_tm_to_time64 covert Gregorian date to seconds since
+ * 01-01-1970 00:00:00, and this date is Thursday.
+ */
+ tm->tm_wday = (time / 86400 + 4) % 7;
+
+exit:
+ return ret;
+}
+
+static int mtk_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct mt6397_rtc *rtc = dev_get_drvdata(dev);
+ int ret;
+ u16 data[RTC_OFFSET_COUNT];
+
+ tm->tm_year -= RTC_MIN_YEAR_OFFSET;
+ tm->tm_mon++;
+
+ data[RTC_OFFSET_SEC] = tm->tm_sec;
+ data[RTC_OFFSET_MIN] = tm->tm_min;
+ data[RTC_OFFSET_HOUR] = tm->tm_hour;
+ data[RTC_OFFSET_DOM] = tm->tm_mday;
+ data[RTC_OFFSET_MTH] = tm->tm_mon;
+ data[RTC_OFFSET_YEAR] = tm->tm_year;
+
+ mutex_lock(&rtc->lock);
+ ret = regmap_bulk_write(rtc->regmap, rtc->addr_base + RTC_TC_SEC,
+ data, RTC_OFFSET_COUNT);
+ if (ret < 0)
+ goto exit;
+
+ /* Time register write to hardware after call trigger function */
+ ret = mtk_rtc_write_trigger(rtc);
+
+exit:
+ mutex_unlock(&rtc->lock);
+ return ret;
+}
+
+static int mtk_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ struct rtc_time *tm = &alm->time;
+ struct mt6397_rtc *rtc = dev_get_drvdata(dev);
+ u32 irqen, pdn2;
+ int ret;
+ u16 data[RTC_OFFSET_COUNT];
+
+ mutex_lock(&rtc->lock);
+ ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_IRQ_EN, &irqen);
+ if (ret < 0)
+ goto err_exit;
+ ret = regmap_read(rtc->regmap, rtc->addr_base + RTC_PDN2, &pdn2);
+ if (ret < 0)
+ goto err_exit;
+
+ ret = regmap_bulk_read(rtc->regmap, rtc->addr_base + RTC_AL_SEC,
+ data, RTC_OFFSET_COUNT);
+ if (ret < 0)
+ goto err_exit;
+
+ alm->enabled = !!(irqen & RTC_IRQ_EN_AL);
+ alm->pending = !!(pdn2 & RTC_PDN2_PWRON_ALARM);
+ mutex_unlock(&rtc->lock);
+
+ tm->tm_sec = data[RTC_OFFSET_SEC];
+ tm->tm_min = data[RTC_OFFSET_MIN];
+ tm->tm_hour = data[RTC_OFFSET_HOUR];
+ tm->tm_mday = data[RTC_OFFSET_DOM];
+ tm->tm_mon = data[RTC_OFFSET_MTH];
+ tm->tm_year = data[RTC_OFFSET_YEAR];
+
+ tm->tm_year += RTC_MIN_YEAR_OFFSET;
+ tm->tm_mon--;
+
+ return 0;
+err_exit:
+ mutex_unlock(&rtc->lock);
+ return ret;
+}
+
+static int mtk_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ struct rtc_time *tm = &alm->time;
+ struct mt6397_rtc *rtc = dev_get_drvdata(dev);
+ int ret;
+ u16 data[RTC_OFFSET_COUNT];
+
+ tm->tm_year -= RTC_MIN_YEAR_OFFSET;
+ tm->tm_mon++;
+
+ data[RTC_OFFSET_SEC] = tm->tm_sec;
+ data[RTC_OFFSET_MIN] = tm->tm_min;
+ data[RTC_OFFSET_HOUR] = tm->tm_hour;
+ data[RTC_OFFSET_DOM] = tm->tm_mday;
+ data[RTC_OFFSET_MTH] = tm->tm_mon;
+ data[RTC_OFFSET_YEAR] = tm->tm_year;
+
+ mutex_lock(&rtc->lock);
+ if (alm->enabled) {
+ ret = regmap_bulk_write(rtc->regmap,
+ rtc->addr_base + RTC_AL_SEC,
+ data, RTC_OFFSET_COUNT);
+ if (ret < 0)
+ goto exit;
+ ret = regmap_write(rtc->regmap, rtc->addr_base + RTC_AL_MASK,
+ RTC_AL_MASK_DOW);
+ if (ret < 0)
+ goto exit;
+ ret = regmap_update_bits(rtc->regmap,
+ rtc->addr_base + RTC_IRQ_EN,
+ RTC_IRQ_EN_ONESHOT_AL,
+ RTC_IRQ_EN_ONESHOT_AL);
+ if (ret < 0)
+ goto exit;
+ } else {
+ ret = regmap_update_bits(rtc->regmap,
+ rtc->addr_base + RTC_IRQ_EN,
+ RTC_IRQ_EN_ONESHOT_AL, 0);
+ if (ret < 0)
+ goto exit;
+ }
+
+ /* All alarm time register write to hardware after calling
+ * mtk_rtc_write_trigger. This can avoid race condition if alarm
+ * occur happen during writing alarm time register.
+ */
+ ret = mtk_rtc_write_trigger(rtc);
+exit:
+ mutex_unlock(&rtc->lock);
+ return ret;
+}
+
+static struct rtc_class_ops mtk_rtc_ops = {
+ .read_time = mtk_rtc_read_time,
+ .set_time = mtk_rtc_set_time,
+ .read_alarm = mtk_rtc_read_alarm,
+ .set_alarm = mtk_rtc_set_alarm,
+};
+
+static int mtk_rtc_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct mt6397_chip *mt6397_chip = dev_get_drvdata(pdev->dev.parent);
+ struct mt6397_rtc *rtc;
+ int ret;
+
+ rtc = devm_kzalloc(&pdev->dev, sizeof(struct mt6397_rtc), GFP_KERNEL);
+ if (!rtc)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ rtc->addr_base = res->start;
+
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ rtc->irq = irq_create_mapping(mt6397_chip->irq_domain, res->start);
+ if (rtc->irq <= 0)
+ return -EINVAL;
+
+ rtc->regmap = mt6397_chip->regmap;
+ rtc->dev = &pdev->dev;
+ mutex_init(&rtc->lock);
+
+ platform_set_drvdata(pdev, rtc);
+
+ ret = request_threaded_irq(rtc->irq, NULL,
+ mtk_rtc_irq_handler_thread,
+ IRQF_ONESHOT | IRQF_TRIGGER_HIGH,
+ "mt6397-rtc", rtc);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
+ rtc->irq, ret);
+ goto out_dispose_irq;
+ }
+
+ rtc->rtc_dev = rtc_device_register("mt6397-rtc", &pdev->dev,
+ &mtk_rtc_ops, THIS_MODULE);
+ if (IS_ERR(rtc->rtc_dev)) {
+ dev_err(&pdev->dev, "register rtc device failed\n");
+ ret = PTR_ERR(rtc->rtc_dev);
+ goto out_free_irq;
+ }
+
+ device_init_wakeup(&pdev->dev, 1);
+
+ return 0;
+
+out_free_irq:
+ free_irq(rtc->irq, rtc->rtc_dev);
+out_dispose_irq:
+ irq_dispose_mapping(rtc->irq);
+ return ret;
+}
+
+static int mtk_rtc_remove(struct platform_device *pdev)
+{
+ struct mt6397_rtc *rtc = platform_get_drvdata(pdev);
+
+ rtc_device_unregister(rtc->rtc_dev);
+ free_irq(rtc->irq, rtc->rtc_dev);
+ irq_dispose_mapping(rtc->irq);
+
+ return 0;
+}
+
+static const struct of_device_id mt6397_rtc_of_match[] = {
+ { .compatible = "mediatek,mt6397-rtc", },
+ { }
+};
+
+static struct platform_driver mtk_rtc_driver = {
+ .driver = {
+ .name = "mt6397-rtc",
+ .of_match_table = mt6397_rtc_of_match,
+ },
+ .probe = mtk_rtc_probe,
+ .remove = mtk_rtc_remove,
+};
+
+module_platform_driver(mtk_rtc_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Tianping Fang <tianping.fang at mediatek.com>");
+MODULE_DESCRIPTION("RTC Driver for MediaTek MT6397 PMIC");
+MODULE_ALIAS("platform:mt6397-rtc");
--
1.8.1.1.dirty
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