[PATCH v2 2/3] rtc: mediatek: Add MT6397 RTC driver

Eddie Huang
2015-03-18T05:45:36Z

From: Tianping Fang <tianping.fang@mediatek.com>

Add Mediatek MT6397 RTC driver

Signed-off-by: Tianping Fang <tianping.fang@mediatek.com>
Signed-off-by: Eddie Huang <eddie.huang@mediatek.com>
---
drivers/rtc/Kconfig | 10 ++
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-mt6397.c | 454 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 465 insertions(+)
create mode 100644 drivers/rtc/rtc-mt6397.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index b5b5c3d..dcb94af 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1510,6 +1510,16 @@ 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 69c8706..85c8bea 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -153,3 +153,4 @@ 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..130480d
--- /dev/null
+++ b/drivers/rtc/rtc-mt6397.c
@@ -0,0 +1,454 @@
+/*
+* Copyright (c) 2014-2015 MediaTek Inc.
+* Author: Tianping.Fang <tianping.fang@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/slab.h>
+#include <linux/kernel.h>
+#include <linux/regmap.h>
+#include <linux/rtc.h>
+#include <linux/irqdomain.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/platform_device.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/kernel.h>
+#include <linux/io.h>
+#include <linux/mfd/mt6397/core.h>
+
+#define RTC_BBPU 0x0000
+#define RTC_WRTGR 0x003c
+#define RTC_IRQ_EN 0x0004
+#define RTC_IRQ_STA 0x0002
+
+#define RTC_BBPU_CBUSY (1 << 6)
+#define RTC_IRQ_STA_AL (1 << 0)
+#define RTC_IRQ_STA_LP (1 << 3)
+
+#define RTC_AL_MASK 0x0008
+#define RTC_TC_SEC 0x000a
+#define RTC_TC_MIN 0x000c
+#define RTC_TC_HOU 0x000e
+#define RTC_TC_DOM 0x0010
+#define RTC_TC_MTH 0x0014
+#define RTC_TC_YEA 0x0016
+#define RTC_AL_SEC 0x0018
+#define RTC_AL_MIN 0x001a
+
+#define RTC_IRQ_EN_AL (1 << 0)
+#define RTC_IRQ_EN_ONESHOT (1 << 2)
+#define RTC_IRQ_EN_LP (1 << 3)
+#define RTC_IRQ_EN_ONESHOT_AL (RTC_IRQ_EN_ONESHOT | RTC_IRQ_EN_AL)
+
+#define RTC_TC_MIN_MASK 0x003f
+#define RTC_TC_SEC_MASK 0x003f
+#define RTC_TC_HOU_MASK 0x001f
+#define RTC_TC_DOM_MASK 0x001f
+#define RTC_TC_MTH_MASK 0x000f
+#define RTC_TC_YEA_MASK 0x007f
+
+#define RTC_AL_SEC_MASK 0x003f
+#define RTC_AL_MIN_MASK 0x003f
+#define RTC_AL_MASK_DOW (1 << 4)
+
+#define RTC_AL_HOU 0x001c
+#define RTC_AL_HOU_MASK 0x001f
+
+#define RTC_AL_DOM 0x001e
+#define RTC_AL_DOM_MASK 0x001f
+
+#define RTC_AL_MTH 0x0022
+#define RTC_AL_MTH_MASK 0x000f
+
+#define RTC_AL_YEA 0x0024
+#define RTC_AL_YEA_MASK 0x007f
+
+#define RTC_PDN2 0x002e
+#define RTC_PDN2_PWRON_MTH_MASK 0x000f
+#define RTC_PDN2_PWRON_MTH_SHIFT 0
+#define RTC_PDN2_PWRON_ALARM (1 << 4)
+#define RTC_PDN2_UART_MASK 0x0060
+#define RTC_PDN2_UART_SHIFT 5
+#define RTC_PDN2_PWRON_YEA_MASK 0x7f00
+#define RTC_PDN2_PWRON_YEA_SHIFT 8
+#define RTC_PDN2_PWRON_LOGO (1 << 15)
+
+#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)
+#define RTC_RELPWR_WHEN_XRST 1
+
+struct mt6397_rtc {
+ struct device *dev;
+ struct rtc_device *rtc_dev;
+ struct mutex lock;
+ struct regmap *regmap;
+ int irq;
+ u32 addr_base;
+ u32 addr_range;
+};
+
+static int mtk_rtc_read(struct mt6397_rtc *rtc, u32 offset, u32 *data)
+{
+ u32 addr = rtc->addr_base + offset;
+
+ if (offset < rtc->addr_range)
+ return regmap_read(rtc->regmap, addr, data);
+
+ return -EINVAL;
+}
+
+static int mtk_rtc_write(struct mt6397_rtc *rtc, u32 offset, u32 data)
+{
+ u32 addr;
+
+ addr = rtc->addr_base + offset;
+
+ if (offset < rtc->addr_range)
+ return regmap_write(rtc->regmap, addr, data);
+
+ return -EINVAL;
+}
+
+static int mtk_rtc_write_trigger(struct mt6397_rtc *rtc)
+{
+ int ret;
+ u32 data;
+
+ ret = mtk_rtc_write(rtc, RTC_WRTGR, 1);
+ if (ret < 0)
+ goto exit;
+
+ ret = mtk_rtc_read(rtc, RTC_BBPU, &data);
+ if (ret < 0)
+ goto exit;
+
+ while (data & RTC_BBPU_CBUSY) {
+ cpu_relax();
+ ret = mtk_rtc_read(rtc, RTC_BBPU, &data);
+ if (ret < 0)
+ goto exit;
+ }
+
+exit:
+ 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 = mtk_rtc_read(rtc, 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 (mtk_rtc_write(rtc, 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;
+
+ mutex_lock(&rtc->lock);
+ ret = mtk_rtc_read(rtc, RTC_TC_SEC, &tm->tm_sec);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_read(rtc, RTC_TC_MIN, &tm->tm_min);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_read(rtc, RTC_TC_HOU, &tm->tm_hour);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_read(rtc, RTC_TC_DOM, &tm->tm_mday);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_read(rtc, RTC_TC_MTH, &tm->tm_mon);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_read(rtc, RTC_TC_YEA, &tm->tm_year);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_read(rtc, 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);
+
+ tm->tm_year += RTC_MIN_YEAR_OFFSET;
+ tm->tm_mon--;
+ time = rtc_tm_to_time64(tm);
+
+ 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;
+
+ tm->tm_year -= RTC_MIN_YEAR_OFFSET;
+ tm->tm_mon++;
+
+ mutex_lock(&rtc->lock);
+ ret = mtk_rtc_write(rtc, RTC_TC_YEA, tm->tm_year);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_write(rtc, RTC_TC_MTH, tm->tm_mon);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_write(rtc, RTC_TC_DOM, tm->tm_mday);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_write(rtc, RTC_TC_HOU, tm->tm_hour);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_write(rtc, RTC_TC_MIN, tm->tm_min);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_write(rtc, RTC_TC_SEC, tm->tm_sec);
+ if (ret < 0)
+ goto exit;
+ 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;
+
+ mutex_lock(&rtc->lock);
+ ret = mtk_rtc_read(rtc, RTC_IRQ_EN, &irqen);
+ if (ret < 0)
+ goto err_exit;
+ ret = mtk_rtc_read(rtc, RTC_PDN2, &pdn2);
+ if (ret < 0)
+ goto err_exit;
+ ret = mtk_rtc_read(rtc, RTC_AL_SEC, &tm->tm_sec);
+ if (ret < 0)
+ goto err_exit;
+ ret = mtk_rtc_read(rtc, RTC_AL_MIN, &tm->tm_min);
+ if (ret < 0)
+ goto err_exit;
+ ret = mtk_rtc_read(rtc, RTC_AL_HOU, &tm->tm_hour);
+ if (ret < 0)
+ goto err_exit;
+ ret = mtk_rtc_read(rtc, RTC_AL_DOM, &tm->tm_mday);
+ if (ret < 0)
+ goto err_exit;
+ ret = mtk_rtc_read(rtc, RTC_AL_MTH, &tm->tm_mon);
+ if (ret < 0)
+ goto err_exit;
+ ret = mtk_rtc_read(rtc, RTC_AL_YEA, &tm->tm_year);
+ 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_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);
+ u32 irqen;
+ int ret;
+
+ tm->tm_year -= RTC_MIN_YEAR_OFFSET;
+ tm->tm_mon++;
+
+ mutex_lock(&rtc->lock);
+ if (alm->enabled) {
+ ret = mtk_rtc_write(rtc, RTC_AL_YEA, tm->tm_year);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_write(rtc, RTC_AL_MTH, tm->tm_mon);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_write(rtc, RTC_AL_DOM, tm->tm_mday);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_write(rtc, RTC_AL_HOU, tm->tm_hour);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_write(rtc, RTC_AL_MIN, tm->tm_min);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_write(rtc, RTC_AL_SEC, tm->tm_sec);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_write(rtc, RTC_AL_MASK, RTC_AL_MASK_DOW);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_write_trigger(rtc);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_read(rtc, RTC_IRQ_EN, &irqen);
+ if (ret < 0)
+ goto exit;
+ irqen |= RTC_IRQ_EN_ONESHOT_AL;
+ ret = mtk_rtc_write(rtc, RTC_IRQ_EN, irqen);
+ if (ret < 0)
+ goto exit;
+ ret = mtk_rtc_write_trigger(rtc);
+ if (ret < 0)
+ goto exit;
+ } else {
+ ret = mtk_rtc_read(rtc, RTC_IRQ_EN, &irqen);
+ if (ret < 0)
+ goto exit;
+ irqen &= ~RTC_IRQ_EN_ONESHOT_AL;
+ ret = mtk_rtc_write(rtc, RTC_IRQ_EN, irqen);
+ if (ret < 0)
+ goto exit;
+ }
+
+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 = 0;
+
+ 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;
+ rtc->addr_range = res->end - 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)
+ goto out_rtc;
+
+ rtc->regmap = mt6397_chip->regmap;
+ rtc->dev = &pdev->dev;
+ mutex_init(&rtc->lock);
+
+ platform_set_drvdata(pdev, rtc);
+
+ ret = devm_request_threaded_irq(&pdev->dev, 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_rtc;
+ }
+
+ 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");
+ return PTR_ERR(rtc->rtc_dev);
+ }
+
+ device_init_wakeup(&pdev->dev, 1);
+
+ return 0;
+
+out_rtc:
+ rtc_device_unregister(rtc->rtc_dev);
+ 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);
+ 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@mediatek.com>");
+MODULE_DESCRIPTION("RTC Driver for MediaTek MT6397 PMIC");
+MODULE_ALIAS("platform:mt6397-rtc");
--
1.8.1.1.dirty