[PATCH v3 2/4] rtc: add support for the MediaTek MT2712 RTC

Ran Bi
2020-02-26T05:13:36Z

This add support for the MediaTek MT2712 RTC. It was SoC based RTC, but
had different architecture compared with MT7622 RTC.

Signed-off-by: Ran Bi <ran.bi@mediatek.com>
---
drivers/rtc/Kconfig | 10 +
drivers/rtc/Makefile | 1 +
drivers/rtc/rtc-mt2712.c | 422 +++++++++++++++++++++++++++++++++++++++
3 files changed, 433 insertions(+)
create mode 100644 drivers/rtc/rtc-mt2712.c

diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 34c8b6c7e095..685fb00bfda1 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -1806,6 +1806,16 @@ 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_MT2712
+ tristate "MediaTek MT2712 SoC based RTC"
+ depends on ARCH_MEDIATEK || COMPILE_TEST
+ help
+ This enables support for the real time clock built in the MediaTek
+ SoCs for MT2712.
+
+ This drive can also be built as a module. If so, the module
+ will be called rtc-mt2712.
+
config RTC_DRV_MT6397
tristate "MediaTek PMIC based RTC"
depends on MFD_MT6397 || (COMPILE_TEST && IRQ_DOMAIN)
diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile
index 4ac8f19fb631..6c3e93aa36dc 100644
--- a/drivers/rtc/Makefile
+++ b/drivers/rtc/Makefile
@@ -110,6 +110,7 @@ obj-$(CONFIG_RTC_DRV_MESON) += rtc-meson.o
obj-$(CONFIG_RTC_DRV_MOXART) += rtc-moxart.o
obj-$(CONFIG_RTC_DRV_MPC5121) += rtc-mpc5121.o
obj-$(CONFIG_RTC_DRV_MSM6242) += rtc-msm6242.o
+obj-$(CONFIG_RTC_DRV_MT2712) += rtc-mt2712.o
obj-$(CONFIG_RTC_DRV_MT6397) += rtc-mt6397.o
obj-$(CONFIG_RTC_DRV_MT7622) += rtc-mt7622.o
obj-$(CONFIG_RTC_DRV_MV) += rtc-mv.o
diff --git a/drivers/rtc/rtc-mt2712.c b/drivers/rtc/rtc-mt2712.c
new file mode 100644
index 000000000000..2cb9392a1cdd
--- /dev/null
+++ b/drivers/rtc/rtc-mt2712.c
@@ -0,0 +1,422 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2019 MediaTek Inc.
+ * Author: Ran Bi <ran.bi@mediatek.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/irqdomain.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/of_irq.h>
+#include <linux/platform_device.h>
+#include <linux/rtc.h>
+
+#define MT2712_BBPU 0x0000
+#define MT2712_BBPU_CLRPKY BIT(4)
+#define MT2712_BBPU_RELOAD BIT(5)
+#define MT2712_BBPU_CBUSY BIT(6)
+#define MT2712_BBPU_KEY (0x43 << 8)
+
+#define MT2712_IRQ_STA 0x0004
+#define MT2712_IRQ_STA_AL BIT(0)
+#define MT2712_IRQ_STA_TC BIT(1)
+
+#define MT2712_IRQ_EN 0x0008
+#define MT2712_IRQ_EN_AL BIT(0)
+#define MT2712_IRQ_EN_TC BIT(1)
+#define MT2712_IRQ_EN_ONESHOT BIT(2)
+
+#define MT2712_CII_EN 0x000c
+
+#define MT2712_AL_MASK 0x0010
+#define MT2712_AL_MASK_DOW BIT(4)
+
+#define MT2712_TC_SEC 0x0014
+#define MT2712_TC_MIN 0x0018
+#define MT2712_TC_HOU 0x001c
+#define MT2712_TC_DOM 0x0020
+#define MT2712_TC_DOW 0x0024
+#define MT2712_TC_MTH 0x0028
+#define MT2712_TC_YEA 0x002c
+
+#define MT2712_AL_SEC 0x0030
+#define MT2712_AL_MIN 0x0034
+#define MT2712_AL_HOU 0x0038
+#define MT2712_AL_DOM 0x003c
+#define MT2712_AL_DOW 0x0040
+#define MT2712_AL_MTH 0x0044
+#define MT2712_AL_YEA 0x0048
+
+#define MT2712_SEC_MASK 0x003f
+#define MT2712_MIN_MASK 0x003f
+#define MT2712_HOU_MASK 0x001f
+#define MT2712_DOM_MASK 0x001f
+#define MT2712_DOW_MASK 0x0007
+#define MT2712_MTH_MASK 0x000f
+#define MT2712_YEA_MASK 0x007f
+
+#define MT2712_POWERKEY1 0x004c
+#define MT2712_POWERKEY2 0x0050
+#define MT2712_POWERKEY1_KEY 0xa357
+#define MT2712_POWERKEY2_KEY 0x67d2
+
+#define MT2712_CON0 0x005c
+#define MT2712_CON1 0x0060
+
+#define MT2712_PROT 0x0070
+#define MT2712_PROT_UNLOCK1 0x9136
+#define MT2712_PROT_UNLOCK2 0x586a
+
+#define MT2712_WRTGR 0x0078
+
+#define MT2712_RTC_TIMESTAMP_END_2127 4985971199LL
+
+struct mt2712_rtc {
+ struct rtc_device *rtc;
+ void __iomem *base;
+ int irq;
+ u8 irq_wake_enabled;
+ u8 powerlost;
+};
+
+static inline u32 mt2712_readl(struct mt2712_rtc *mt2712_rtc, u32 reg)
+{
+ return readl(mt2712_rtc->base + reg);
+}
+
+static inline void mt2712_writel(struct mt2712_rtc *mt2712_rtc,
+ u32 reg, u32 val)
+{
+ writel(val, mt2712_rtc->base + reg);
+}
+
+static void mt2712_rtc_write_trigger(struct mt2712_rtc *mt2712_rtc)
+{
+ unsigned long timeout = jiffies + HZ / 10;
+
+ mt2712_writel(mt2712_rtc, MT2712_WRTGR, 1);
+ while (1) {
+ if (!(mt2712_readl(mt2712_rtc, MT2712_BBPU)
+ & MT2712_BBPU_CBUSY))
+ break;
+
+ if (time_after(jiffies, timeout)) {
+ dev_err(&mt2712_rtc->rtc->dev,
+ "%s time out!\n", __func__);
+ break;
+ }
+ cpu_relax();
+ }
+}
+
+static void mt2712_rtc_writeif_unlock(struct mt2712_rtc *mt2712_rtc)
+{
+ mt2712_writel(mt2712_rtc, MT2712_PROT, MT2712_PROT_UNLOCK1);
+ mt2712_rtc_write_trigger(mt2712_rtc);
+ mt2712_writel(mt2712_rtc, MT2712_PROT, MT2712_PROT_UNLOCK2);
+ mt2712_rtc_write_trigger(mt2712_rtc);
+}
+
+static irqreturn_t rtc_irq_handler_thread(int irq, void *data)
+{
+ struct mt2712_rtc *mt2712_rtc = data;
+ u16 irqsta;
+
+ /* Clear interrupt */
+ irqsta = mt2712_readl(mt2712_rtc, MT2712_IRQ_STA);
+ if (irqsta & MT2712_IRQ_STA_AL) {
+ rtc_update_irq(mt2712_rtc->rtc, 1, RTC_IRQF | RTC_AF);
+ return IRQ_HANDLED;
+ }
+
+ return IRQ_NONE;
+}
+
+static void __mt2712_rtc_read_time(struct mt2712_rtc *mt2712_rtc,
+ struct rtc_time *tm, int *sec)
+{
+ tm->tm_sec = mt2712_readl(mt2712_rtc, MT2712_TC_SEC)
+ & MT2712_SEC_MASK;
+ tm->tm_min = mt2712_readl(mt2712_rtc, MT2712_TC_MIN)
+ & MT2712_MIN_MASK;
+ tm->tm_hour = mt2712_readl(mt2712_rtc, MT2712_TC_HOU)
+ & MT2712_HOU_MASK;
+ tm->tm_mday = mt2712_readl(mt2712_rtc, MT2712_TC_DOM)
+ & MT2712_DOM_MASK;
+ tm->tm_mon = (mt2712_readl(mt2712_rtc, MT2712_TC_MTH) - 1)
+ & MT2712_MTH_MASK;
+ tm->tm_year = (mt2712_readl(mt2712_rtc, MT2712_TC_YEA) + 100)
+ & MT2712_YEA_MASK;
+
+ *sec = mt2712_readl(mt2712_rtc, MT2712_TC_SEC) & MT2712_SEC_MASK;
+}
+
+static int mt2712_rtc_read_time(struct device *dev, struct rtc_time *tm)
+{
+ struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
+ int sec;
+
+ if (mt2712_rtc->powerlost)
+ return -EINVAL;
+
+ do {
+ __mt2712_rtc_read_time(mt2712_rtc, tm, &sec);
+ } while (sec < tm->tm_sec); /* SEC has carried */
+
+ return 0;
+}
+
+static int mt2712_rtc_set_time(struct device *dev, struct rtc_time *tm)
+{
+ struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
+
+ mt2712_writel(mt2712_rtc, MT2712_TC_SEC, tm->tm_sec & MT2712_SEC_MASK);
+ mt2712_writel(mt2712_rtc, MT2712_TC_MIN, tm->tm_min & MT2712_MIN_MASK);
+ mt2712_writel(mt2712_rtc, MT2712_TC_HOU, tm->tm_hour & MT2712_HOU_MASK);
+ mt2712_writel(mt2712_rtc, MT2712_TC_DOM, tm->tm_mday & MT2712_DOM_MASK);
+ mt2712_writel(mt2712_rtc, MT2712_TC_MTH,
+ (tm->tm_mon + 1) & MT2712_MTH_MASK);
+ mt2712_writel(mt2712_rtc, MT2712_TC_YEA,
+ (tm->tm_year - 100) & MT2712_YEA_MASK);
+
+ mt2712_rtc_write_trigger(mt2712_rtc);
+
+ if (mt2712_rtc->powerlost)
+ mt2712_rtc->powerlost = false;
+
+ return 0;
+}
+
+static int mt2712_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
+ struct rtc_time *tm = &alm->time;
+ u16 irqen;
+
+ irqen = mt2712_readl(mt2712_rtc, MT2712_IRQ_EN);
+ alm->enabled = !!(irqen & MT2712_IRQ_EN_AL);
+
+ tm->tm_sec = mt2712_readl(mt2712_rtc, MT2712_AL_SEC) & MT2712_SEC_MASK;
+ tm->tm_min = mt2712_readl(mt2712_rtc, MT2712_AL_MIN) & MT2712_MIN_MASK;
+ tm->tm_hour = mt2712_readl(mt2712_rtc, MT2712_AL_HOU) & MT2712_HOU_MASK;
+ tm->tm_mday = mt2712_readl(mt2712_rtc, MT2712_AL_DOM) & MT2712_DOM_MASK;
+ tm->tm_mon = (mt2712_readl(mt2712_rtc, MT2712_AL_MTH) - 1)
+ & MT2712_MTH_MASK;
+ tm->tm_year = (mt2712_readl(mt2712_rtc, MT2712_AL_YEA) + 100)
+ & MT2712_YEA_MASK;
+
+ return 0;
+}
+
+static int mt2712_rtc_alarm_irq_enable(struct device *dev,
+ unsigned int enabled)
+{
+ struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
+ u16 irqen;
+
+ irqen = mt2712_readl(mt2712_rtc, MT2712_IRQ_EN);
+ if (enabled)
+ irqen |= MT2712_IRQ_EN_AL;
+ else
+ irqen &= ~MT2712_IRQ_EN_AL;
+ mt2712_writel(mt2712_rtc, MT2712_IRQ_EN, irqen);
+ mt2712_rtc_write_trigger(mt2712_rtc);
+
+ return 0;
+}
+
+static int mt2712_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alm)
+{
+ struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
+ struct rtc_time *tm = &alm->time;
+ u16 irqen;
+
+ dev_dbg(&mt2712_rtc->rtc->dev, "set al time: %ptR, alm en: %d\n",
+ tm, alm->enabled);
+
+ mt2712_writel(mt2712_rtc, MT2712_AL_SEC,
+ (mt2712_readl(mt2712_rtc, MT2712_AL_SEC)
+ & ~(MT2712_SEC_MASK)) | (tm->tm_sec & MT2712_SEC_MASK));
+ mt2712_writel(mt2712_rtc, MT2712_AL_MIN,
+ (mt2712_readl(mt2712_rtc, MT2712_AL_MIN)
+ & ~(MT2712_MIN_MASK)) | (tm->tm_min & MT2712_MIN_MASK));
+ mt2712_writel(mt2712_rtc, MT2712_AL_HOU,
+ (mt2712_readl(mt2712_rtc, MT2712_AL_HOU)
+ & ~(MT2712_HOU_MASK)) | (tm->tm_hour & MT2712_HOU_MASK));
+ mt2712_writel(mt2712_rtc, MT2712_AL_DOM,
+ (mt2712_readl(mt2712_rtc, MT2712_AL_DOM)
+ & ~(MT2712_DOM_MASK)) | (tm->tm_mday & MT2712_DOM_MASK));
+ mt2712_writel(mt2712_rtc, MT2712_AL_MTH,
+ (mt2712_readl(mt2712_rtc, MT2712_AL_MTH)
+ & ~(MT2712_MTH_MASK))
+ | ((tm->tm_mon + 1) & MT2712_MTH_MASK));
+ mt2712_writel(mt2712_rtc, MT2712_AL_YEA,
+ (mt2712_readl(mt2712_rtc, MT2712_AL_YEA)
+ & ~(MT2712_YEA_MASK))
+ | ((tm->tm_year - 100) & MT2712_YEA_MASK));
+
+ /* mask day of week */
+ mt2712_writel(mt2712_rtc, MT2712_AL_MASK, MT2712_AL_MASK_DOW);
+ mt2712_rtc_write_trigger(mt2712_rtc);
+
+ mt2712_rtc_alarm_irq_enable(dev, alm->enabled);
+
+ return 0;
+}
+
+/* Init RTC register */
+static void mt2712_rtc_hw_init(struct mt2712_rtc *mt2712_rtc)
+{
+ u32 p1, p2;
+
+ mt2712_writel(mt2712_rtc, MT2712_BBPU,
+ MT2712_BBPU_KEY | MT2712_BBPU_RELOAD);
+
+ mt2712_writel(mt2712_rtc, MT2712_CII_EN, 0);
+ mt2712_writel(mt2712_rtc, MT2712_AL_MASK, 0);
+ /* necessary before set MT2712_POWERKEY */
+ mt2712_writel(mt2712_rtc, MT2712_CON0, 0x4848);
+ mt2712_writel(mt2712_rtc, MT2712_CON1, 0x0048);
+
+ mt2712_rtc_write_trigger(mt2712_rtc);
+
+ p1 = mt2712_readl(mt2712_rtc, MT2712_POWERKEY1);
+ p2 = mt2712_readl(mt2712_rtc, MT2712_POWERKEY2);
+ if (p1 != MT2712_POWERKEY1_KEY || p2 != MT2712_POWERKEY2_KEY) {
+ mt2712_rtc->powerlost = true;
+ dev_dbg(&mt2712_rtc->rtc->dev,
+ "powerkey not set (lost power)\n");
+ } else {
+ mt2712_rtc->powerlost = false;
+ }
+
+ /* RTC need POWERKEY1/2 match, then goto normal work mode */
+ mt2712_writel(mt2712_rtc, MT2712_POWERKEY1, MT2712_POWERKEY1_KEY);
+ mt2712_writel(mt2712_rtc, MT2712_POWERKEY2, MT2712_POWERKEY2_KEY);
+ mt2712_rtc_write_trigger(mt2712_rtc);
+
+ mt2712_rtc_writeif_unlock(mt2712_rtc);
+}
+
+static const struct rtc_class_ops mt2712_rtc_ops = {
+ .read_time = mt2712_rtc_read_time,
+ .set_time = mt2712_rtc_set_time,
+ .read_alarm = mt2712_rtc_read_alarm,
+ .set_alarm = mt2712_rtc_set_alarm,
+ .alarm_irq_enable = mt2712_rtc_alarm_irq_enable,
+};
+
+static int mt2712_rtc_probe(struct platform_device *pdev)
+{
+ struct resource *res;
+ struct mt2712_rtc *mt2712_rtc;
+ int ret;
+
+ mt2712_rtc = devm_kzalloc(&pdev->dev,
+ sizeof(struct mt2712_rtc), GFP_KERNEL);
+ if (!mt2712_rtc)
+ return -ENOMEM;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ mt2712_rtc->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(mt2712_rtc->base))
+ return PTR_ERR(mt2712_rtc->base);
+
+ /* rtc hw init */
+ mt2712_rtc_hw_init(mt2712_rtc);
+
+ mt2712_rtc->irq = platform_get_irq(pdev, 0);
+ if (mt2712_rtc->irq < 0) {
+ dev_err(&pdev->dev, "No IRQ resource\n");
+ return mt2712_rtc->irq;
+ }
+
+ platform_set_drvdata(pdev, mt2712_rtc);
+
+ mt2712_rtc->rtc = devm_rtc_allocate_device(&pdev->dev);
+ if (IS_ERR(mt2712_rtc->rtc))
+ return PTR_ERR(mt2712_rtc->rtc);
+
+ ret = devm_request_threaded_irq(&pdev->dev, mt2712_rtc->irq, NULL,
+ rtc_irq_handler_thread,
+ IRQF_ONESHOT | IRQF_TRIGGER_LOW,
+ dev_name(&mt2712_rtc->rtc->dev),
+ mt2712_rtc);
+ if (ret) {
+ dev_err(&pdev->dev, "Failed to request alarm IRQ: %d: %d\n",
+ mt2712_rtc->irq, ret);
+ return ret;
+ }
+
+ device_init_wakeup(&pdev->dev, true);
+
+ mt2712_rtc->rtc->ops = &mt2712_rtc_ops;
+ mt2712_rtc->rtc->range_min = RTC_TIMESTAMP_BEGIN_2000;
+ mt2712_rtc->rtc->range_max = MT2712_RTC_TIMESTAMP_END_2127;
+
+ ret = rtc_register_device(mt2712_rtc->rtc);
+ if (ret) {
+ dev_err(&pdev->dev, "register rtc device failed\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int mt2712_rtc_suspend(struct device *dev)
+{
+ int wake_status = 0;
+ struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev)) {
+ wake_status = enable_irq_wake(mt2712_rtc->irq);
+ if (!wake_status)
+ mt2712_rtc->irq_wake_enabled = true;
+ }
+
+ return 0;
+}
+
+static int mt2712_rtc_resume(struct device *dev)
+{
+ int wake_status = 0;
+ struct mt2712_rtc *mt2712_rtc = dev_get_drvdata(dev);
+
+ if (device_may_wakeup(dev) && mt2712_rtc->irq_wake_enabled) {
+ wake_status = disable_irq_wake(mt2712_rtc->irq);
+ if (!wake_status)
+ mt2712_rtc->irq_wake_enabled = false;
+ }
+
+ return 0;
+}
+
+static SIMPLE_DEV_PM_OPS(mt2712_pm_ops, mt2712_rtc_suspend,
+ mt2712_rtc_resume);
+#endif
+
+static const struct of_device_id mt2712_rtc_of_match[] = {
+ { .compatible = "mediatek,mt2712-rtc", },
+ { },
+};
+
+MODULE_DEVICE_TABLE(of, mt2712_rtc_of_match)
+
+static struct platform_driver mt2712_rtc_driver = {
+ .driver = {
+ .name = "mt2712-rtc",
+ .of_match_table = mt2712_rtc_of_match,
+ .pm = &mt2712_pm_ops,
+ },
+ .probe = mt2712_rtc_probe,
+};
+
+module_platform_driver(mt2712_rtc_driver);
+
+MODULE_DESCRIPTION("MediaTek MT2712 SoC based RTC Driver");
+MODULE_AUTHOR("Ran Bi <ran.bi@mediatek.com>");
+MODULE_LICENSE("GPL");
--
2.25.0