| Message ID | 20210819170301.10520-3-romain.perier@gmail.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add RTC for MStar SoCs | expand |
Hi! 2021年8月20日(金) 2:03 Romain Perier <romain.perier@gmail.com>: > > From: Daniel Palmer <daniel@0x0f.com> > > This adds support for the RTC block on the Mstar MSC313e SoCs and newer. > > Signed-off-by: Daniel Palmer <daniel@0x0f.com> > Co-developed-by: Romain Perier <romain.perier@gmail.com> > Signed-off-by: Romain Perier <romain.perier@gmail.com> > --- > MAINTAINERS | 1 + > drivers/rtc/Kconfig | 10 ++ > drivers/rtc/Makefile | 1 + > drivers/rtc/rtc-msc313.c | 258 +++++++++++++++++++++++++++++++++++++++ > 4 files changed, 270 insertions(+) > create mode 100644 drivers/rtc/rtc-msc313.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index fd25e4ecf0b9..ebacdd5e8878 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -2220,6 +2220,7 @@ F: arch/arm/boot/dts/mstar-* > F: arch/arm/mach-mstar/ > F: drivers/clk/mstar/ > F: drivers/gpio/gpio-msc313.c > +F: drivers/rtc/rtc-msc313.c > F: drivers/watchdog/msc313e_wdt.c > F: include/dt-bindings/clock/mstar-* > F: include/dt-bindings/gpio/msc313-gpio.h > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index 12153d5801ce..9ce4baab5fcf 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -1925,4 +1925,14 @@ config RTC_DRV_WILCO_EC > This can also be built as a module. If so, the module will > be named "rtc_wilco_ec". > > +config RTC_DRV_MSC313 > + tristate "MStar MSC313 RTC" > + depends on ARCH_MSTARV7 || COMPILE_TEST > + help > + If you say yes here you get support for the Mstar MSC313e On-Chip > + Real Time Clock. > + > + This driver can also be built as a module, if so, the module > + will be called "rtc-msc313". > + > endif # RTC_CLASS > diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile > index 2dd0dd956b0e..5efda8a60cee 100644 > --- a/drivers/rtc/Makefile > +++ b/drivers/rtc/Makefile > @@ -101,6 +101,7 @@ obj-$(CONFIG_RTC_DRV_MCP795) += rtc-mcp795.o > obj-$(CONFIG_RTC_DRV_MESON) += rtc-meson.o > obj-$(CONFIG_RTC_DRV_MOXART) += rtc-moxart.o > obj-$(CONFIG_RTC_DRV_MPC5121) += rtc-mpc5121.o > +obj-$(CONFIG_RTC_DRV_MSC313) += rtc-msc313.o > obj-$(CONFIG_RTC_DRV_MSM6242) += rtc-msm6242.o > obj-$(CONFIG_RTC_DRV_MT2712) += rtc-mt2712.o > obj-$(CONFIG_RTC_DRV_MT6397) += rtc-mt6397.o > diff --git a/drivers/rtc/rtc-msc313.c b/drivers/rtc/rtc-msc313.c > new file mode 100644 > index 000000000000..8cf5d5fb298f > --- /dev/null > +++ b/drivers/rtc/rtc-msc313.c > @@ -0,0 +1,258 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * Real time clocks driver for MStar/SigmaStar ARMv7 SoCs. > + * Based on "Real Time Clock driver for msb252x." that was contained > + * in various MStar kernels. > + * > + * (C) 2019 Daniel Palmer > + * (C) 2021 Romain Perier > + */ > + > +#include <linux/clk.h> > +#include <linux/delay.h> > +#include <linux/module.h> > +#include <linux/mod_devicetable.h> > +#include <linux/platform_device.h> > +#include <linux/rtc.h> > + > +/* Registers */ > +#define REG_RTC_CTRL 0x00 > +#define REG_RTC_FREQ_CW_L 0x04 > +#define REG_RTC_FREQ_CW_H 0x08 > +#define REG_RTC_LOAD_VAL_L 0x0C > +#define REG_RTC_LOAD_VAL_H 0x10 > +#define REG_RTC_MATCH_VAL_L 0x14 > +#define REG_RTC_MATCH_VAL_H 0x18 > +#define REG_RTC_STATUS_INT 0x1C > +#define REG_RTC_CNT_VAL_L 0x20 > +#define REG_RTC_CNT_VAL_H 0x24 > + > +/* Control bits for REG_RTC_CTRL */ > +#define SOFT_RSTZ_BIT BIT(0) > +#define CNT_EN_BIT BIT(1) > +#define WRAP_EN_BIT BIT(2) > +#define LOAD_EN_BIT BIT(3) > +#define READ_EN_BIT BIT(4) > +#define INT_MASK_BIT BIT(5) > +#define INT_FORCE_BIT BIT(6) > +#define INT_CLEAR_BIT BIT(7) > + > +/* Control bits for REG_RTC_STATUS_INT */ > +#define RAW_INT_BIT BIT(0) > +#define ALM_INT_BIT BIT(1) > + > +struct msc313_rtc { > + struct rtc_device *rtc_dev; > + void __iomem *rtc_base; > + struct clk *clk; The clk variable is only used in msc313_rtc_probe(). Therefore, it is not necessary to have it in this structure. > +}; > + > +static int msc313_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) > +{ > + struct msc313_rtc *priv = dev_get_drvdata(dev); > + unsigned long seconds; > + > + seconds = readw(priv->rtc_base + REG_RTC_MATCH_VAL_L) > + | (readw(priv->rtc_base + REG_RTC_MATCH_VAL_H) << 16); > + > + rtc_time64_to_tm(seconds, &alarm->time); > + > + if (!(readw(priv->rtc_base + REG_RTC_CTRL) & INT_MASK_BIT)) > + alarm->enabled = 1; > + > + return 0; > +} > + > +static int msc313_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) > +{ > + struct msc313_rtc *priv = dev_get_drvdata(dev); > + u16 reg; > + > + reg = readw(priv->rtc_base + REG_RTC_CTRL); > + if (enabled) > + reg &= ~INT_MASK_BIT; > + else > + reg |= INT_MASK_BIT; > + writew(reg, priv->rtc_base + REG_RTC_CTRL); > + return 0; > +} > + > +static int msc313_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) > +{ > + struct msc313_rtc *priv = dev_get_drvdata(dev); > + unsigned long seconds; > + > + seconds = rtc_tm_to_time64(&alarm->time); > + writew((seconds & 0xFFFF), priv->rtc_base + REG_RTC_MATCH_VAL_L); > + writew((seconds >> 16) & 0xFFFF, priv->rtc_base + REG_RTC_MATCH_VAL_H); > + > + msc313_rtc_alarm_irq_enable(dev, alarm->enabled); > + > + return 0; > +} > + > +static bool msc313_rtc_get_enabled(struct msc313_rtc *priv) > +{ > + return readw(priv->rtc_base + REG_RTC_CTRL) & CNT_EN_BIT; > +} > + > +static void msc313_rtc_set_enabled(struct msc313_rtc *priv) > +{ > + u16 reg; > + > + reg = readw(priv->rtc_base + REG_RTC_CTRL); > + reg |= CNT_EN_BIT; > + writew(reg, priv->rtc_base + REG_RTC_CTRL); > +} > + > +static int msc313_rtc_read_time(struct device *dev, struct rtc_time *tm) > +{ > + struct msc313_rtc *priv = dev_get_drvdata(dev); > + u32 seconds; > + u16 reg; > + > + if (!msc313_rtc_get_enabled(priv)) > + return -EINVAL; > + > + reg = readw(priv->rtc_base + REG_RTC_CTRL); > + writew(reg | READ_EN_BIT, priv->rtc_base + REG_RTC_CTRL); > + > + /* Wait for HW latch done */ > + while (readw(priv->rtc_base + REG_RTC_CTRL) & READ_EN_BIT) > + udelay(1); > + > + seconds = readw(priv->rtc_base + REG_RTC_CNT_VAL_L) > + | (readw(priv->rtc_base + REG_RTC_CNT_VAL_H) << 16); > + > + rtc_time64_to_tm(seconds, tm); > + > + return 0; > +} > + > +static int msc313_rtc_set_time(struct device *dev, struct rtc_time *tm) > +{ > + struct msc313_rtc *priv = dev_get_drvdata(dev); > + unsigned long seconds; > + u16 reg; > + > + seconds = rtc_tm_to_time64(tm); > + writew(seconds & 0xFFFF, priv->rtc_base + REG_RTC_LOAD_VAL_L); > + writew((seconds >> 16) & 0xFFFF, priv->rtc_base + REG_RTC_LOAD_VAL_H); > + > + /* Enable load for loading value into internal RTC counter */ > + reg = readw(priv->rtc_base + REG_RTC_CTRL); > + writew(reg | LOAD_EN_BIT, priv->rtc_base + REG_RTC_CTRL); > + > + /* Wait for HW latch done */ > + while (readw(priv->rtc_base + REG_RTC_CTRL) & LOAD_EN_BIT) > + udelay(1); > + msc313_rtc_set_enabled(priv); > + return 0; > +} > + > +static const struct rtc_class_ops msc313_rtc_ops = { > + .read_time = msc313_rtc_read_time, > + .set_time = msc313_rtc_set_time, > + .read_alarm = msc313_rtc_read_alarm, > + .set_alarm = msc313_rtc_set_alarm, > + .alarm_irq_enable = msc313_rtc_alarm_irq_enable, > +}; > + > +static irqreturn_t msc313_rtc_interrupt(s32 irq, void *dev_id) > +{ > + struct msc313_rtc *priv = dev_get_drvdata(dev_id); > + u16 reg; > + > + reg = readw(priv->rtc_base + REG_RTC_STATUS_INT); > + if (!(reg & ALM_INT_BIT)) > + return IRQ_NONE; > + > + reg = readw(priv->rtc_base + REG_RTC_CTRL); > + reg |= INT_CLEAR_BIT; > + reg &= ~INT_FORCE_BIT; > + writew(reg, priv->rtc_base + REG_RTC_CTRL); > + > + rtc_update_irq(priv->rtc_dev, 1, RTC_IRQF | RTC_AF); > + > + return IRQ_HANDLED; > +} > + > +static int msc313_rtc_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct msc313_rtc *priv; > + int ret; > + int irq; > + unsigned long rate; Please use reverse christmas tree ordering for local variable. > + > + priv = devm_kzalloc(&pdev->dev, sizeof(struct msc313_rtc), GFP_KERNEL); > + if (!priv) > + return -ENOMEM; > + > + priv->rtc_base = devm_platform_ioremap_resource(pdev, 0); > + if (IS_ERR(priv->rtc_base)) > + return PTR_ERR(priv->rtc_base); > + > + irq = platform_get_irq(pdev, 0); > + if (irq < 0) > + return -EINVAL; > + > + priv->rtc_dev = devm_rtc_allocate_device(dev); > + if (IS_ERR(priv->rtc_dev)) > + return PTR_ERR(priv->rtc_dev); > + > + priv->rtc_dev->ops = &msc313_rtc_ops; > + priv->rtc_dev->range_max = U32_MAX; > + > + ret = devm_request_irq(dev, irq, msc313_rtc_interrupt, IRQF_SHARED, > + dev_name(&pdev->dev), &pdev->dev); > + if (ret) { > + dev_err(dev, "Could not request IRQ\n"); > + return ret; > + } > + > + priv->clk = devm_clk_get(dev, NULL); > + if (IS_ERR(priv->clk)) { > + dev_err(dev, "No input reference clock\n"); > + return PTR_ERR(priv->clk); > + } > + > + ret = clk_prepare_enable(priv->clk); > + if (ret) { > + dev_err(dev, "Failed to enable the reference clock, %d\n", ret); > + return ret; > + } > + > + ret = devm_add_action_or_reset(dev, (void (*) (void *))clk_disable_unprepare, priv->clk); > + if (ret) > + return ret; > + > + rate = clk_get_rate(priv->clk); > + writew(rate & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_L); > + writew((rate >> 16) & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_H); > + > + platform_set_drvdata(pdev, priv); > + > + return devm_rtc_register_device(priv->rtc_dev); > +} > + > +static const struct of_device_id msc313_rtc_of_match_table[] = { > + { .compatible = "mstar,msc313-rtc" }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, ms_rtc_of_match_table); msc313_rtc_of_match_table ? > + > +static struct platform_driver msc313_rtc_driver = { > + .probe = msc313_rtc_probe, > + .driver = { > + .name = "msc313-rtc", > + .of_match_table = msc313_rtc_of_match_table, > + }, > +}; > + > +module_platform_driver(msc313_rtc_driver); > + > +MODULE_AUTHOR("Daniel Palmer <daniel@thingy.jp>"); > +MODULE_AUTHOR("Romain Perier <romain.perier@gmail.com>"); > +MODULE_DESCRIPTION("MStar RTC Driver"); > +MODULE_LICENSE("GPL v2"); > -- > 2.30.2 > Best regards, Nobuhiro -- Nobuhiro Iwamatsu iwamatsu at {nigauri.org / debian.org / kernel.org} GPG ID: 40AD1FA6
diff --git a/MAINTAINERS b/MAINTAINERS index fd25e4ecf0b9..ebacdd5e8878 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -2220,6 +2220,7 @@ F: arch/arm/boot/dts/mstar-* F: arch/arm/mach-mstar/ F: drivers/clk/mstar/ F: drivers/gpio/gpio-msc313.c +F: drivers/rtc/rtc-msc313.c F: drivers/watchdog/msc313e_wdt.c F: include/dt-bindings/clock/mstar-* F: include/dt-bindings/gpio/msc313-gpio.h diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index 12153d5801ce..9ce4baab5fcf 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -1925,4 +1925,14 @@ config RTC_DRV_WILCO_EC This can also be built as a module. If so, the module will be named "rtc_wilco_ec". +config RTC_DRV_MSC313 + tristate "MStar MSC313 RTC" + depends on ARCH_MSTARV7 || COMPILE_TEST + help + If you say yes here you get support for the Mstar MSC313e On-Chip + Real Time Clock. + + This driver can also be built as a module, if so, the module + will be called "rtc-msc313". + endif # RTC_CLASS diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 2dd0dd956b0e..5efda8a60cee 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -101,6 +101,7 @@ obj-$(CONFIG_RTC_DRV_MCP795) += rtc-mcp795.o obj-$(CONFIG_RTC_DRV_MESON) += rtc-meson.o obj-$(CONFIG_RTC_DRV_MOXART) += rtc-moxart.o obj-$(CONFIG_RTC_DRV_MPC5121) += rtc-mpc5121.o +obj-$(CONFIG_RTC_DRV_MSC313) += rtc-msc313.o obj-$(CONFIG_RTC_DRV_MSM6242) += rtc-msm6242.o obj-$(CONFIG_RTC_DRV_MT2712) += rtc-mt2712.o obj-$(CONFIG_RTC_DRV_MT6397) += rtc-mt6397.o diff --git a/drivers/rtc/rtc-msc313.c b/drivers/rtc/rtc-msc313.c new file mode 100644 index 000000000000..8cf5d5fb298f --- /dev/null +++ b/drivers/rtc/rtc-msc313.c @@ -0,0 +1,258 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Real time clocks driver for MStar/SigmaStar ARMv7 SoCs. + * Based on "Real Time Clock driver for msb252x." that was contained + * in various MStar kernels. + * + * (C) 2019 Daniel Palmer + * (C) 2021 Romain Perier + */ + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/platform_device.h> +#include <linux/rtc.h> + +/* Registers */ +#define REG_RTC_CTRL 0x00 +#define REG_RTC_FREQ_CW_L 0x04 +#define REG_RTC_FREQ_CW_H 0x08 +#define REG_RTC_LOAD_VAL_L 0x0C +#define REG_RTC_LOAD_VAL_H 0x10 +#define REG_RTC_MATCH_VAL_L 0x14 +#define REG_RTC_MATCH_VAL_H 0x18 +#define REG_RTC_STATUS_INT 0x1C +#define REG_RTC_CNT_VAL_L 0x20 +#define REG_RTC_CNT_VAL_H 0x24 + +/* Control bits for REG_RTC_CTRL */ +#define SOFT_RSTZ_BIT BIT(0) +#define CNT_EN_BIT BIT(1) +#define WRAP_EN_BIT BIT(2) +#define LOAD_EN_BIT BIT(3) +#define READ_EN_BIT BIT(4) +#define INT_MASK_BIT BIT(5) +#define INT_FORCE_BIT BIT(6) +#define INT_CLEAR_BIT BIT(7) + +/* Control bits for REG_RTC_STATUS_INT */ +#define RAW_INT_BIT BIT(0) +#define ALM_INT_BIT BIT(1) + +struct msc313_rtc { + struct rtc_device *rtc_dev; + void __iomem *rtc_base; + struct clk *clk; +}; + +static int msc313_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct msc313_rtc *priv = dev_get_drvdata(dev); + unsigned long seconds; + + seconds = readw(priv->rtc_base + REG_RTC_MATCH_VAL_L) + | (readw(priv->rtc_base + REG_RTC_MATCH_VAL_H) << 16); + + rtc_time64_to_tm(seconds, &alarm->time); + + if (!(readw(priv->rtc_base + REG_RTC_CTRL) & INT_MASK_BIT)) + alarm->enabled = 1; + + return 0; +} + +static int msc313_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled) +{ + struct msc313_rtc *priv = dev_get_drvdata(dev); + u16 reg; + + reg = readw(priv->rtc_base + REG_RTC_CTRL); + if (enabled) + reg &= ~INT_MASK_BIT; + else + reg |= INT_MASK_BIT; + writew(reg, priv->rtc_base + REG_RTC_CTRL); + return 0; +} + +static int msc313_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alarm) +{ + struct msc313_rtc *priv = dev_get_drvdata(dev); + unsigned long seconds; + + seconds = rtc_tm_to_time64(&alarm->time); + writew((seconds & 0xFFFF), priv->rtc_base + REG_RTC_MATCH_VAL_L); + writew((seconds >> 16) & 0xFFFF, priv->rtc_base + REG_RTC_MATCH_VAL_H); + + msc313_rtc_alarm_irq_enable(dev, alarm->enabled); + + return 0; +} + +static bool msc313_rtc_get_enabled(struct msc313_rtc *priv) +{ + return readw(priv->rtc_base + REG_RTC_CTRL) & CNT_EN_BIT; +} + +static void msc313_rtc_set_enabled(struct msc313_rtc *priv) +{ + u16 reg; + + reg = readw(priv->rtc_base + REG_RTC_CTRL); + reg |= CNT_EN_BIT; + writew(reg, priv->rtc_base + REG_RTC_CTRL); +} + +static int msc313_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct msc313_rtc *priv = dev_get_drvdata(dev); + u32 seconds; + u16 reg; + + if (!msc313_rtc_get_enabled(priv)) + return -EINVAL; + + reg = readw(priv->rtc_base + REG_RTC_CTRL); + writew(reg | READ_EN_BIT, priv->rtc_base + REG_RTC_CTRL); + + /* Wait for HW latch done */ + while (readw(priv->rtc_base + REG_RTC_CTRL) & READ_EN_BIT) + udelay(1); + + seconds = readw(priv->rtc_base + REG_RTC_CNT_VAL_L) + | (readw(priv->rtc_base + REG_RTC_CNT_VAL_H) << 16); + + rtc_time64_to_tm(seconds, tm); + + return 0; +} + +static int msc313_rtc_set_time(struct device *dev, struct rtc_time *tm) +{ + struct msc313_rtc *priv = dev_get_drvdata(dev); + unsigned long seconds; + u16 reg; + + seconds = rtc_tm_to_time64(tm); + writew(seconds & 0xFFFF, priv->rtc_base + REG_RTC_LOAD_VAL_L); + writew((seconds >> 16) & 0xFFFF, priv->rtc_base + REG_RTC_LOAD_VAL_H); + + /* Enable load for loading value into internal RTC counter */ + reg = readw(priv->rtc_base + REG_RTC_CTRL); + writew(reg | LOAD_EN_BIT, priv->rtc_base + REG_RTC_CTRL); + + /* Wait for HW latch done */ + while (readw(priv->rtc_base + REG_RTC_CTRL) & LOAD_EN_BIT) + udelay(1); + msc313_rtc_set_enabled(priv); + return 0; +} + +static const struct rtc_class_ops msc313_rtc_ops = { + .read_time = msc313_rtc_read_time, + .set_time = msc313_rtc_set_time, + .read_alarm = msc313_rtc_read_alarm, + .set_alarm = msc313_rtc_set_alarm, + .alarm_irq_enable = msc313_rtc_alarm_irq_enable, +}; + +static irqreturn_t msc313_rtc_interrupt(s32 irq, void *dev_id) +{ + struct msc313_rtc *priv = dev_get_drvdata(dev_id); + u16 reg; + + reg = readw(priv->rtc_base + REG_RTC_STATUS_INT); + if (!(reg & ALM_INT_BIT)) + return IRQ_NONE; + + reg = readw(priv->rtc_base + REG_RTC_CTRL); + reg |= INT_CLEAR_BIT; + reg &= ~INT_FORCE_BIT; + writew(reg, priv->rtc_base + REG_RTC_CTRL); + + rtc_update_irq(priv->rtc_dev, 1, RTC_IRQF | RTC_AF); + + return IRQ_HANDLED; +} + +static int msc313_rtc_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct msc313_rtc *priv; + int ret; + int irq; + unsigned long rate; + + priv = devm_kzalloc(&pdev->dev, sizeof(struct msc313_rtc), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->rtc_base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(priv->rtc_base)) + return PTR_ERR(priv->rtc_base); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return -EINVAL; + + priv->rtc_dev = devm_rtc_allocate_device(dev); + if (IS_ERR(priv->rtc_dev)) + return PTR_ERR(priv->rtc_dev); + + priv->rtc_dev->ops = &msc313_rtc_ops; + priv->rtc_dev->range_max = U32_MAX; + + ret = devm_request_irq(dev, irq, msc313_rtc_interrupt, IRQF_SHARED, + dev_name(&pdev->dev), &pdev->dev); + if (ret) { + dev_err(dev, "Could not request IRQ\n"); + return ret; + } + + priv->clk = devm_clk_get(dev, NULL); + if (IS_ERR(priv->clk)) { + dev_err(dev, "No input reference clock\n"); + return PTR_ERR(priv->clk); + } + + ret = clk_prepare_enable(priv->clk); + if (ret) { + dev_err(dev, "Failed to enable the reference clock, %d\n", ret); + return ret; + } + + ret = devm_add_action_or_reset(dev, (void (*) (void *))clk_disable_unprepare, priv->clk); + if (ret) + return ret; + + rate = clk_get_rate(priv->clk); + writew(rate & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_L); + writew((rate >> 16) & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_H); + + platform_set_drvdata(pdev, priv); + + return devm_rtc_register_device(priv->rtc_dev); +} + +static const struct of_device_id msc313_rtc_of_match_table[] = { + { .compatible = "mstar,msc313-rtc" }, + { } +}; +MODULE_DEVICE_TABLE(of, ms_rtc_of_match_table); + +static struct platform_driver msc313_rtc_driver = { + .probe = msc313_rtc_probe, + .driver = { + .name = "msc313-rtc", + .of_match_table = msc313_rtc_of_match_table, + }, +}; + +module_platform_driver(msc313_rtc_driver); + +MODULE_AUTHOR("Daniel Palmer <daniel@thingy.jp>"); +MODULE_AUTHOR("Romain Perier <romain.perier@gmail.com>"); +MODULE_DESCRIPTION("MStar RTC Driver"); +MODULE_LICENSE("GPL v2");