| Message ID | 20210720172251.4504-3-romain.perier@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add RTC for MStar SoCs | expand |
Hello Romain, On 20/07/2021 19:22:50+0200, Romain Perier wrote: > 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 | 246 +++++++++++++++++++++++++++++++++++++++ > 4 files changed, 258 insertions(+) > create mode 100644 drivers/rtc/rtc-msc313.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 6c8be735cc91..7e8d1a375e0d 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..67870b422bc5 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 maybe ? > + 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 > +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; > + > + 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 rtc_valid_tm(tm); This is not necessary, tm is valid at that point (and the core will check anyway). > +} > + > +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); > + reg = readw(priv->rtc_base + REG_RTC_CTRL); > + writew(reg | LOAD_EN_BIT, priv->rtc_base + REG_RTC_CTRL); > + > + /* need to check carefully if we want to clear REG_RTC_LOAD_VAL_H for customer*/ > + while (readw(priv->rtc_base + REG_RTC_CTRL) & LOAD_EN_BIT) > + udelay(1); > + writew(0, priv->rtc_base + REG_RTC_LOAD_VAL_H); Why is that necessary? The comment is not super useful here. > + > + 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_relaxed(priv->rtc_base + REG_RTC_CTRL); > + reg |= INT_CLEAR_BIT; > + reg &= ~INT_FORCE_BIT; > + writew_relaxed(reg, priv->rtc_base + REG_RTC_CTRL); > + I'm not convinced the _relaxed functions are doing the right thing here. Also, shouldn't you check the alarm actually fired? > + rtc_update_irq(priv->rtc_dev, 1, RTC_IRQF | RTC_AF); > + > + return IRQ_HANDLED; > +} > + > +static int msc313_rtc_remove(struct platform_device *pdev) > +{ > + struct msc313_rtc *priv = platform_get_drvdata(pdev); > + > + clk_disable_unprepare(priv->clk); With a nice devm_add_action_or_reset() in the probe, you can remove the need for msc313_rtc_remove(). > + > + return 0; > +} > + > +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; > + u16 reg; > + > + 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; > + > + ret = devm_request_irq(dev, irq, msc313_rtc_interrupt, IRQF_SHARED, > + dev_name(&pdev->dev), &pdev->dev); > + if (ret) { > + dev_err(dev, "Unable to 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; > + } > + > + rate = clk_get_rate(priv->clk); > + > + reg = readw(priv->rtc_base + REG_RTC_CTRL); > + if (!(reg & SOFT_RSTZ_BIT)) { > + reg |= SOFT_RSTZ_BIT; > + writew(reg, priv->rtc_base + REG_RTC_CTRL); > + } What is the meaning of this bit? I would think it is better to use that to know whether the RTC holds the correct time instead of killing the info here. > + > + writew(rate & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_L); > + writew((rate >> 16) & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_H); > + > + reg |= CNT_EN_BIT; > + writew(reg, priv->rtc_base + REG_RTC_CTRL); > + > + platform_set_drvdata(pdev, priv); > + > + priv->rtc_dev = devm_rtc_device_register(dev, dev_name(dev), &msc313_rtc_ops, THIS_MODULE); > + if (IS_ERR(priv->rtc_dev)) { > + dev_err(dev, "Failed to register rtc device\n"); > + return PTR_ERR(priv->rtc_dev); > + } Please switch to devm_rtc_allocate_device and devm_rtc_register_device. Also drop the error message, it is not necessary. You must also set the RTC range. To help you, you can use: https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/rtc-tools.git/tree/rtc-range.c then you must update the DT bindings as the RTC will support the start-year property You must also run rtctest and should include the results.
Hello Alexandre, Le mar. 20 juil. 2021 à 22:01, Alexandre Belloni <alexandre.belloni@bootlin.com> a écrit : > > Hello Romain, > > On 20/07/2021 19:22:50+0200, Romain Perier wrote: > > 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 | 246 +++++++++++++++++++++++++++++++++++++++ > > 4 files changed, 258 insertions(+) > > create mode 100644 drivers/rtc/rtc-msc313.c > > > > diff --git a/MAINTAINERS b/MAINTAINERS > > index 6c8be735cc91..7e8d1a375e0d 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..67870b422bc5 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 maybe ? Arf, I always forget this option. Ack, I will add it in v2. > > > + 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 > > > > +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; > > + > > + 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 rtc_valid_tm(tm); > > This is not necessary, tm is valid at that point (and the core will > check anyway). ack. > > > +} > > + > > +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); > > + reg = readw(priv->rtc_base + REG_RTC_CTRL); > > + writew(reg | LOAD_EN_BIT, priv->rtc_base + REG_RTC_CTRL); > > + > > + /* need to check carefully if we want to clear REG_RTC_LOAD_VAL_H for customer*/ > > + while (readw(priv->rtc_base + REG_RTC_CTRL) & LOAD_EN_BIT) > > + udelay(1); > > + writew(0, priv->rtc_base + REG_RTC_LOAD_VAL_H); > > Why is that necessary? The comment is not super useful here. > > > + > > + 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_relaxed(priv->rtc_base + REG_RTC_CTRL); > > + reg |= INT_CLEAR_BIT; > > + reg &= ~INT_FORCE_BIT; > > + writew_relaxed(reg, priv->rtc_base + REG_RTC_CTRL); > > + > > I'm not convinced the _relaxed functions are doing the right thing here. Good catch for the _relaxed, I did not pay attention during refactoring. > Also, shouldn't you check the alarm actually fired? You mean before set the flag "RTC_AF" ? This driver is mostly based on reverse engineering, even if we have some hardware info. I will try to find if it is possible (I mean, from the info I have). > > > + rtc_update_irq(priv->rtc_dev, 1, RTC_IRQF | RTC_AF); > > + > > + return IRQ_HANDLED; > > +} > > + > > +static int msc313_rtc_remove(struct platform_device *pdev) > > +{ > > + struct msc313_rtc *priv = platform_get_drvdata(pdev); > > + > > + clk_disable_unprepare(priv->clk); > > With a nice devm_add_action_or_reset() in the probe, you can remove the > need for msc313_rtc_remove(). devm_add_action_or_reset() you said, interesting I did not know this function. > > > + > > + return 0; > > +} > > + > > +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; > > + u16 reg; > > + > > + 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; > > + > > + ret = devm_request_irq(dev, irq, msc313_rtc_interrupt, IRQF_SHARED, > > + dev_name(&pdev->dev), &pdev->dev); > > + if (ret) { > > + dev_err(dev, "Unable to 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; > > + } > > + > > + rate = clk_get_rate(priv->clk); > > + > > + reg = readw(priv->rtc_base + REG_RTC_CTRL); > > + if (!(reg & SOFT_RSTZ_BIT)) { > > + reg |= SOFT_RSTZ_BIT; > > + writew(reg, priv->rtc_base + REG_RTC_CTRL); > > + } > > What is the meaning of this bit? I would think it is better to use that > to know whether the RTC holds the correct time instead of killing the > info here. > > > + > > + writew(rate & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_L); > > + writew((rate >> 16) & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_H); > > + > > + reg |= CNT_EN_BIT; > > + writew(reg, priv->rtc_base + REG_RTC_CTRL); > > + > > + platform_set_drvdata(pdev, priv); > > + > > + priv->rtc_dev = devm_rtc_device_register(dev, dev_name(dev), &msc313_rtc_ops, THIS_MODULE); > > + if (IS_ERR(priv->rtc_dev)) { > > + dev_err(dev, "Failed to register rtc device\n"); > > + return PTR_ERR(priv->rtc_dev); > > + } > > Please switch to devm_rtc_allocate_device and devm_rtc_register_device. > Also drop the error message, it is not necessary. > > You must also set the RTC range. To help you, you can use: > https://git.kernel.org/pub/scm/linux/kernel/git/abelloni/rtc-tools.git/tree/rtc-range.c > then you must update the DT bindings as the RTC will support the > start-year property > > You must also run rtctest and should include the results. Ack, I will do this in v2. Thanks!
diff --git a/MAINTAINERS b/MAINTAINERS index 6c8be735cc91..7e8d1a375e0d 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..67870b422bc5 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 + 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..b1102e3c93ba --- /dev/null +++ b/drivers/rtc/rtc-msc313.c @@ -0,0 +1,246 @@ +// 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_CNT_VAL_L 0x20 +#define REG_RTC_CNT_VAL_H 0x24 + +#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) + +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 int msc313_rtc_read_time(struct device *dev, struct rtc_time *tm) +{ + struct msc313_rtc *priv = dev_get_drvdata(dev); + u32 seconds; + u16 reg; + + 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 rtc_valid_tm(tm); +} + +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); + reg = readw(priv->rtc_base + REG_RTC_CTRL); + writew(reg | LOAD_EN_BIT, priv->rtc_base + REG_RTC_CTRL); + + /* need to check carefully if we want to clear REG_RTC_LOAD_VAL_H for customer*/ + while (readw(priv->rtc_base + REG_RTC_CTRL) & LOAD_EN_BIT) + udelay(1); + writew(0, priv->rtc_base + REG_RTC_LOAD_VAL_H); + + 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_relaxed(priv->rtc_base + REG_RTC_CTRL); + reg |= INT_CLEAR_BIT; + reg &= ~INT_FORCE_BIT; + writew_relaxed(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_remove(struct platform_device *pdev) +{ + struct msc313_rtc *priv = platform_get_drvdata(pdev); + + clk_disable_unprepare(priv->clk); + + return 0; +} + +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; + u16 reg; + + 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; + + ret = devm_request_irq(dev, irq, msc313_rtc_interrupt, IRQF_SHARED, + dev_name(&pdev->dev), &pdev->dev); + if (ret) { + dev_err(dev, "Unable to 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; + } + + rate = clk_get_rate(priv->clk); + + reg = readw(priv->rtc_base + REG_RTC_CTRL); + if (!(reg & SOFT_RSTZ_BIT)) { + reg |= SOFT_RSTZ_BIT; + writew(reg, priv->rtc_base + REG_RTC_CTRL); + } + + writew(rate & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_L); + writew((rate >> 16) & 0xFFFF, priv->rtc_base + REG_RTC_FREQ_CW_H); + + reg |= CNT_EN_BIT; + writew(reg, priv->rtc_base + REG_RTC_CTRL); + + platform_set_drvdata(pdev, priv); + + priv->rtc_dev = devm_rtc_device_register(dev, dev_name(dev), &msc313_rtc_ops, THIS_MODULE); + if (IS_ERR(priv->rtc_dev)) { + dev_err(dev, "Failed to register rtc device\n"); + return PTR_ERR(priv->rtc_dev); + } + + return 0; +} + +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 = { + .remove = msc313_rtc_remove, + .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");