Message ID | 5b2a7e5c9c5bc179f89e48fb614b2ae789be4254.1506049341.git.sean.wang@mediatek.com (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Hi, On 22/09/2017 at 11:33:15 +0800, sean.wang@mediatek.com wrote: > diff --git a/drivers/rtc/rtc-mediatek.c b/drivers/rtc/rtc-mediatek.c I'm pretty sure this should be named rtc-mt7622.c instead of rtc-mediatek.c, exactly for the same reason you have patch 3/4. > +static void mtk_w32(struct mtk_rtc *rtc, u32 reg, u32 val) > +{ > + __raw_writel(val, rtc->base + reg); Do you really need the __raw accessors? What about running your SoC in BE mode? I guess the _relaxed version are fast enough. > +} > + > +static u32 mtk_r32(struct mtk_rtc *rtc, u32 reg) > +{ > + return __raw_readl(rtc->base + reg); > +} > + > +static void mtk_rtc_hw_init(struct mtk_rtc *hw) > +{ > + /* The setup of the init sequence is for allowing RTC got to work */ > + mtk_w32(hw, MTK_RTC_PWRCHK1, RTC_PWRCHK1_MAGIC); > + mtk_w32(hw, MTK_RTC_PWRCHK2, RTC_PWRCHK2_MAGIC); > + mtk_w32(hw, MTK_RTC_KEY, RTC_KEY_MAGIC); > + mtk_w32(hw, MTK_RTC_PROT1, RTC_PROT1_MAGIC); > + mtk_w32(hw, MTK_RTC_PROT2, RTC_PROT2_MAGIC); > + mtk_w32(hw, MTK_RTC_PROT3, RTC_PROT3_MAGIC); > + mtk_w32(hw, MTK_RTC_PROT4, RTC_PROT4_MAGIC); > + mtk_rmw(hw, MTK_RTC_DEBNCE, RTC_DEBNCE_MASK, 0); > + mtk_clr(hw, MTK_RTC_CTL, RTC_RC_STOP); > +} > + > +static void mtk_rtc_get_alarm_or_time(struct mtk_rtc *hw, struct rtc_time *tm, > + int time_alarm) > +{ > + u32 year, mon, mday, wday, hour, min, sec; > + > + /* > + * Read again until all fields are not changed for all fields in the > + * consistent state. > + */ > + do { > + year = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_YEA)); > + mon = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MON)); > + wday = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOW)); > + mday = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOM)); > + hour = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_HOU)); > + min = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MIN)); > + sec = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC)); > + } while (year != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_YEA)) || > + mon != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MON)) || > + mday != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOM)) || > + wday != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOW)) || > + hour != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_HOU)) || > + min != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MIN)) || > + sec != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC)) > + ); I'm pretty sure only checking sec is enough because it is highly unlikely that 7 reads take a minute. > +static irqreturn_t mtk_rtc_alarmirq(int irq, void *id) > +{ > + struct mtk_rtc *hw = (struct mtk_rtc *)id; > + u32 irq_sta; > + > + /* Stop alarm also implicitly disable the alarm interrupt */ > + mtk_w32(hw, MTK_RTC_AL_CTL, 0); You stop the alarm here, before testing whether the alarm really happened. > + irq_sta = mtk_r32(hw, MTK_RTC_INT); > + if (irq_sta & RTC_INT_AL_STA) { > + rtc_update_irq(hw->rtc, 1, RTC_IRQF | RTC_AF); > + > + /* Ack alarm interrupt status */ > + mtk_w32(hw, MTK_RTC_INT, RTC_INT_AL_STA); > + return IRQ_HANDLED; > + } > + > + return IRQ_NONE; > +} > + > +static int mtk_rtc_gettime(struct device *dev, struct rtc_time *tm) > +{ > + struct mtk_rtc *hw = dev_get_drvdata(dev); > + > + mtk_rtc_get_alarm_or_time(hw, tm, MTK_TC); > + > + return rtc_valid_tm(tm); > +} > + > +static int mtk_rtc_settime(struct device *dev, struct rtc_time *tm) > +{ > + struct mtk_rtc *hw = dev_get_drvdata(dev); > + > + /* Stop time counter before setting a new one*/ > + mtk_set(hw, MTK_RTC_CTL, RTC_RC_STOP); > + > + /* Epoch == 1900 */ > + if (tm->tm_year < 100 || tm->tm_year > 199) > + return -EINVAL; Year is a 32 bits register, what makes the RTC fail in 2100? Is it because of the leap year handling? > +static int mtk_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm) > +{ > + struct mtk_rtc *hw = dev_get_drvdata(dev); > + struct rtc_time *alrm_tm = &wkalrm->time; > + > + /* Epoch == 1900 */ > + if (alrm_tm->tm_year < 100 || alrm_tm->tm_year > 199) > + return -EINVAL; > + Ditto. > + > + dev_info(&pdev->dev, "MediaTek SoC based RTC enabled\n"); > + I think the rtc core is verbose enough that this message is not needed.
Hi Alexandre, Thanks for your valuable suggestions on the driver. I added comments inline and will have following-ups in the next version Sean On Thu, 2017-10-12 at 23:20 +0200, Alexandre Belloni wrote: > Hi, > > On 22/09/2017 at 11:33:15 +0800, sean.wang@mediatek.com wrote: > > diff --git a/drivers/rtc/rtc-mediatek.c b/drivers/rtc/rtc-mediatek.c > > I'm pretty sure this should be named rtc-mt7622.c instead of > rtc-mediatek.c, exactly for the same reason you have patch 3/4. > It's okay for naming with rtc-mt7622.c at this moment. But if more SoCs support gets into the driver, I will consider again to give a more generic name for the driver. > > +static void mtk_w32(struct mtk_rtc *rtc, u32 reg, u32 val) > > +{ > > + __raw_writel(val, rtc->base + reg); > > Do you really need the __raw accessors? What about running your SoC in > BE mode? I guess the _relaxed version are fast enough. > SoC runs on LE mode. I also think it's fine and enough to use _relaxed version instead of __raw version. > > +} > > + > > +static u32 mtk_r32(struct mtk_rtc *rtc, u32 reg) > > +{ > > + return __raw_readl(rtc->base + reg); > > +} > > + > > > > +static void mtk_rtc_hw_init(struct mtk_rtc *hw) > > +{ > > + /* The setup of the init sequence is for allowing RTC got to work */ > > + mtk_w32(hw, MTK_RTC_PWRCHK1, RTC_PWRCHK1_MAGIC); > > + mtk_w32(hw, MTK_RTC_PWRCHK2, RTC_PWRCHK2_MAGIC); > > + mtk_w32(hw, MTK_RTC_KEY, RTC_KEY_MAGIC); > > + mtk_w32(hw, MTK_RTC_PROT1, RTC_PROT1_MAGIC); > > + mtk_w32(hw, MTK_RTC_PROT2, RTC_PROT2_MAGIC); > > + mtk_w32(hw, MTK_RTC_PROT3, RTC_PROT3_MAGIC); > > + mtk_w32(hw, MTK_RTC_PROT4, RTC_PROT4_MAGIC); > > + mtk_rmw(hw, MTK_RTC_DEBNCE, RTC_DEBNCE_MASK, 0); > > + mtk_clr(hw, MTK_RTC_CTL, RTC_RC_STOP); > > +} > > + > > +static void mtk_rtc_get_alarm_or_time(struct mtk_rtc *hw, struct rtc_time *tm, > > + int time_alarm) > > +{ > > + u32 year, mon, mday, wday, hour, min, sec; > > + > > + /* > > + * Read again until all fields are not changed for all fields in the > > + * consistent state. > > + */ > > + do { > > + year = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_YEA)); > > + mon = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MON)); > > + wday = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOW)); > > + mday = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOM)); > > + hour = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_HOU)); > > + min = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MIN)); > > + sec = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC)); > > + } while (year != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_YEA)) || > > + mon != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MON)) || > > + mday != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOM)) || > > + wday != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOW)) || > > + hour != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_HOU)) || > > + min != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MIN)) || > > + sec != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC)) > > + ); > > I'm pretty sure only checking sec is enough because it is highly > unlikely that 7 reads take a minute. > You're right. I made something stupid here. Only checking on sec is enough and will give simpler and better code. > > +static irqreturn_t mtk_rtc_alarmirq(int irq, void *id) > > +{ > > + struct mtk_rtc *hw = (struct mtk_rtc *)id; > > + u32 irq_sta; > > + > > + /* Stop alarm also implicitly disable the alarm interrupt */ > > + mtk_w32(hw, MTK_RTC_AL_CTL, 0); > > You stop the alarm here, before testing whether the alarm really > happened. > Okay. I will exchange the order for alarm stopping and the examination whether the alarm is really expired. > > + irq_sta = mtk_r32(hw, MTK_RTC_INT); > > + if (irq_sta & RTC_INT_AL_STA) { > > + rtc_update_irq(hw->rtc, 1, RTC_IRQF | RTC_AF); > > + > > + /* Ack alarm interrupt status */ > > + mtk_w32(hw, MTK_RTredundantC_INT, RTC_INT_AL_STA); > > + return IRQ_HANDLED; > > + } > > + > > + return IRQ_NONE; > > +} > > + > > +static int mtk_rtc_gettime(struct device *dev, struct rtc_time *tm) > > +{ > > + struct mtk_rtc *hw = dev_get_drvdata(dev); > > + > > + mtk_rtc_get_alarm_or_time(hw, tm, MTK_TC); > > + > > + return rtc_valid_tm(tm); > > +} > > + > > +static int mtk_rtc_settime(struct device *dev, struct rtc_time *tm) > > +{ > > + struct mtk_rtc *hw = dev_get_drvdata(dev); > > + > > + /* Stop time counter before setting a new one*/ > > + mtk_set(hw, MTK_RTC_CTL, RTC_RC_STOP); > > + > > + /* Epoch == 1900 */ > > + if (tm->tm_year < 100 || tm->tm_year > 199) > > + return -EINVAL; > > Year is a 32 bits register, what makes the RTC fail in 2100? Is it > because of the leap year handling? > I made something stupid again here: rtc hardware doesn't have such the limitation. I just felt alarm set up prior to 2100 is enough in my initial thought, but it seemed I shouldn't do this. I will remove the sanity condition. > > +static int mtk_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm) > > +{ > > + struct mtk_rtc *hw = dev_get_drvdata(dev); > > + struct rtc_time *alrm_tm = &wkalrm->time; > > + > > + /* Epoch == 1900 */ > > + if (alrm_tm->tm_year < 100 || alrm_tm->tm_year > 199) > > + return -EINVAL; > > + > > Ditto. > Ditto. those condition will be removed. > > + > > + dev_info(&pdev->dev, "MediaTek SoC based RTC enabled\n"); > > + > > I think the rtc core is verbose enough that this message is not needed. > Okay. the redundant and specific log prompt would be removed as well. >
On Mon, 2017-10-16 at 16:17 +0800, Sean Wang wrote: > Hi Alexandre, > > Thanks for your valuable suggestions on the driver. > > I added comments inline and will have following-ups in the next version > > Sean > > On Thu, 2017-10-12 at 23:20 +0200, Alexandre Belloni wrote: > > Hi, > > > > On 22/09/2017 at 11:33:15 +0800, sean.wang@mediatek.com wrote: > > > diff --git a/drivers/rtc/rtc-mediatek.c b/drivers/rtc/rtc-mediatek.c > > > > I'm pretty sure this should be named rtc-mt7622.c instead of > > rtc-mediatek.c, exactly for the same reason you have patch 3/4. > > > > It's okay for naming with rtc-mt7622.c at this moment. But if more SoCs > support gets into the driver, I will consider again to give a more > generic name for the driver. > > > > +static void mtk_w32(struct mtk_rtc *rtc, u32 reg, u32 val) > > > +{ > > > + __raw_writel(val, rtc->base + reg); > > > > Do you really need the __raw accessors? What about running your SoC in > > BE mode? I guess the _relaxed version are fast enough. > > > > SoC runs on LE mode. I also think it's fine and enough to use _relaxed > version instead of __raw version. > > > > +} > > > + > > > +static u32 mtk_r32(struct mtk_rtc *rtc, u32 reg) > > > +{ > > > + return __raw_readl(rtc->base + reg); > > > +} > > > + > > > > > > > +static void mtk_rtc_hw_init(struct mtk_rtc *hw) > > > +{ > > > + /* The setup of the init sequence is for allowing RTC got to work */ > > > + mtk_w32(hw, MTK_RTC_PWRCHK1, RTC_PWRCHK1_MAGIC); > > > + mtk_w32(hw, MTK_RTC_PWRCHK2, RTC_PWRCHK2_MAGIC); > > > + mtk_w32(hw, MTK_RTC_KEY, RTC_KEY_MAGIC); > > > + mtk_w32(hw, MTK_RTC_PROT1, RTC_PROT1_MAGIC); > > > + mtk_w32(hw, MTK_RTC_PROT2, RTC_PROT2_MAGIC); > > > + mtk_w32(hw, MTK_RTC_PROT3, RTC_PROT3_MAGIC); > > > + mtk_w32(hw, MTK_RTC_PROT4, RTC_PROT4_MAGIC); > > > + mtk_rmw(hw, MTK_RTC_DEBNCE, RTC_DEBNCE_MASK, 0); > > > + mtk_clr(hw, MTK_RTC_CTL, RTC_RC_STOP); > > > +} > > > + > > > +static void mtk_rtc_get_alarm_or_time(struct mtk_rtc *hw, struct rtc_time *tm, > > > + int time_alarm) > > > +{ > > > + u32 year, mon, mday, wday, hour, min, sec; > > > + > > > + /* > > > + * Read again until all fields are not changed for all fields in the > > > + * consistent state. > > > + */ > > > + do { > > > + year = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_YEA)); > > > + mon = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MON)); > > > + wday = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOW)); > > > + mday = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOM)); > > > + hour = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_HOU)); > > > + min = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MIN)); > > > + sec = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC)); > > > + } while (year != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_YEA)) || > > > + mon != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MON)) || > > > + mday != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOM)) || > > > + wday != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOW)) || > > > + hour != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_HOU)) || > > > + min != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MIN)) || > > > + sec != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC)) > > > + ); > > > > I'm pretty sure only checking sec is enough because it is highly > > unlikely that 7 reads take a minute. > > > > You're right. I made something stupid here. Only checking on sec is > enough and will give simpler and better code. > > > > +static irqreturn_t mtk_rtc_alarmirq(int irq, void *id) > > > +{ > > > + struct mtk_rtc *hw = (struct mtk_rtc *)id; > > > + u32 irq_sta; > > > + > > > + /* Stop alarm also implicitly disable the alarm interrupt */ > > > + mtk_w32(hw, MTK_RTC_AL_CTL, 0); > > > > You stop the alarm here, before testing whether the alarm really > > happened. > > > > Okay. I will exchange the order for alarm stopping and the examination > whether the alarm is really expired. > > > > + irq_sta = mtk_r32(hw, MTK_RTC_INT); > > > + if (irq_sta & RTC_INT_AL_STA) { > > > + rtc_update_irq(hw->rtc, 1, RTC_IRQF | RTC_AF); > > > + > > > + /* Ack alarm interrupt status */ > > > + mtk_w32(hw, MTK_RTredundantC_INT, RTC_INT_AL_STA); > > > + return IRQ_HANDLED; > > > + } > > > + > > > + return IRQ_NONE; > > > +} > > > + > > > +static int mtk_rtc_gettime(struct device *dev, struct rtc_time *tm) > > > +{ > > > + struct mtk_rtc *hw = dev_get_drvdata(dev); > > > + > > > + mtk_rtc_get_alarm_or_time(hw, tm, MTK_TC); > > > + > > > + return rtc_valid_tm(tm); > > > +} > > > + > > > +static int mtk_rtc_settime(struct device *dev, struct rtc_time *tm) > > > +{ > > > + struct mtk_rtc *hw = dev_get_drvdata(dev); > > > + > > > + /* Stop time counter before setting a new one*/ > > > + mtk_set(hw, MTK_RTC_CTL, RTC_RC_STOP); > > > + > > > + /* Epoch == 1900 */ > > > + if (tm->tm_year < 100 || tm->tm_year > 199) > > > + return -EINVAL; > > > > Year is a 32 bits register, what makes the RTC fail in 2100? Is it > > because of the leap year handling? > > > > I made something stupid again here: rtc hardware doesn't have such the > limitation. I just felt alarm set up prior to 2100 is enough in my > initial thought, but it seemed I shouldn't do this. I will remove the > sanity condition. > Sorry for that I gave incorrect information for the RTC in the previous reply: After check again the usage of the register, the maximum number of the year the RTC can hold is 99 and then wraparound to 0 when overflow occurs although the year register is a 32 bits register. Therefore, the sanity for tm->tm_year is still required for the both setup handler on alarm and rtc to ensure the user input data is valid, where the current driver assume it's valid when tm->tm_year is between 2000 and 2099. I'll add more comments for the hardware limitation. Sean > > > > +static int mtk_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm) > > > +{ > > > + struct mtk_rtc *hw = dev_get_drvdata(dev); > > > + struct rtc_time *alrm_tm = &wkalrm->time; > > > + > > > + /* Epoch == 1900 */ > > > + if (alrm_tm->tm_year < 100 || alrm_tm->tm_year > 199) > > > + return -EINVAL; > > > + > > > > Ditto. > > > Ditto. those condition will be removed. > > > > + > > > + dev_info(&pdev->dev, "MediaTek SoC based RTC enabled\n"); > > > + > > > > I think the rtc core is verbose enough that this message is not needed. > > > > Okay. the redundant and specific log prompt would be removed as well. > > > > >
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig index e0e58f3..4226295 100644 --- a/drivers/rtc/Kconfig +++ b/drivers/rtc/Kconfig @@ -1705,6 +1705,16 @@ 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_MEDIATEK + tristate "MediaTek SoC based RTC" + depends on ARCH_MEDIATEK || COMPILE_TEST + help + This enables support for the real time clock built in the MediaTek + SoCs. + + This drive can also be built as a module. If so, the module + will be called rtc-mediatek. + config RTC_DRV_MT6397 tristate "Mediatek Real Time Clock driver" depends on MFD_MT6397 || (COMPILE_TEST && IRQ_DOMAIN) diff --git a/drivers/rtc/Makefile b/drivers/rtc/Makefile index 7230014..ba0206a 100644 --- a/drivers/rtc/Makefile +++ b/drivers/rtc/Makefile @@ -101,6 +101,7 @@ obj-$(CONFIG_RTC_DRV_MOXART) += rtc-moxart.o obj-$(CONFIG_RTC_DRV_MPC5121) += rtc-mpc5121.o obj-$(CONFIG_RTC_DRV_VRTC) += rtc-mrst.o obj-$(CONFIG_RTC_DRV_MSM6242) += rtc-msm6242.o +obj-$(CONFIG_RTC_DRV_MEDIATEK) += rtc-mediatek.o obj-$(CONFIG_RTC_DRV_MT6397) += rtc-mt6397.o obj-$(CONFIG_RTC_DRV_MV) += rtc-mv.o obj-$(CONFIG_RTC_DRV_MXC) += rtc-mxc.o diff --git a/drivers/rtc/rtc-mediatek.c b/drivers/rtc/rtc-mediatek.c new file mode 100644 index 0000000..c6c06fe --- /dev/null +++ b/drivers/rtc/rtc-mediatek.c @@ -0,0 +1,398 @@ +/* + * Driver for MediaTek SoC based RTC + * + * Copyright (C) 2017 Sean Wang <sean.wang@mediatek.com> + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * 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/clk.h> +#include <linux/interrupt.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/rtc.h> + +#define MTK_RTC_DEV KBUILD_MODNAME + +#define MTK_RTC_PWRCHK1 0x4 +#define RTC_PWRCHK1_MAGIC 0xc6 + +#define MTK_RTC_PWRCHK2 0x8 +#define RTC_PWRCHK2_MAGIC 0x9a + +#define MTK_RTC_KEY 0xc +#define RTC_KEY_MAGIC 0x59 + +#define MTK_RTC_PROT1 0x10 +#define RTC_PROT1_MAGIC 0xa3 + +#define MTK_RTC_PROT2 0x14 +#define RTC_PROT2_MAGIC 0x57 + +#define MTK_RTC_PROT3 0x18 +#define RTC_PROT3_MAGIC 0x67 + +#define MTK_RTC_PROT4 0x1c +#define RTC_PROT4_MAGIC 0xd2 + +#define MTK_RTC_CTL 0x20 +#define RTC_RC_STOP BIT(0) + +#define MTK_RTC_DEBNCE 0x2c +#define RTC_DEBNCE_MASK GENMASK(2, 0) + +#define MTK_RTC_INT 0x30 +#define RTC_INT_AL_STA BIT(4) + +/* Ranges from 0x40 to 0x78 provide RTC time setup for year, month, + * day of month, day of week, hour, minute and second. + */ +#define MTK_RTC_TREG(_t, _f) (0x40 + (0x4 * (_f)) + ((_t) * 0x20)) + +#define MTK_RTC_AL_CTL 0x7c +#define RTC_AL_EN BIT(0) +#define RTC_AL_ALL GENMASK(7, 0) + +/* Types of the function the RTC provides are time counter and alarm. */ +enum { + MTK_TC, + MTK_AL +}; + +/* Indexes are used for the pointer to relevant registers in MTK_RTC_TREG */ +enum { + MTK_YEA, + MTK_MON, + MTK_DOM, + MTK_DOW, + MTK_HOU, + MTK_MIN, + MTK_SEC +}; + +struct mtk_rtc { + struct rtc_device *rtc; + void __iomem *base; + int irq; + struct clk *clk; +}; + +static void mtk_w32(struct mtk_rtc *rtc, u32 reg, u32 val) +{ + __raw_writel(val, rtc->base + reg); +} + +static u32 mtk_r32(struct mtk_rtc *rtc, u32 reg) +{ + return __raw_readl(rtc->base + reg); +} + +static void mtk_rmw(struct mtk_rtc *rtc, u32 reg, u32 mask, u32 set) +{ + u32 val; + + val = mtk_r32(rtc, reg); + val &= ~mask; + val |= set; + mtk_w32(rtc, reg, val); +} + +static void mtk_set(struct mtk_rtc *rtc, u32 reg, u32 val) +{ + mtk_rmw(rtc, reg, 0, val); +} + +static void mtk_clr(struct mtk_rtc *rtc, u32 reg, u32 val) +{ + mtk_rmw(rtc, reg, val, 0); +} + +static void mtk_rtc_hw_init(struct mtk_rtc *hw) +{ + /* The setup of the init sequence is for allowing RTC got to work */ + mtk_w32(hw, MTK_RTC_PWRCHK1, RTC_PWRCHK1_MAGIC); + mtk_w32(hw, MTK_RTC_PWRCHK2, RTC_PWRCHK2_MAGIC); + mtk_w32(hw, MTK_RTC_KEY, RTC_KEY_MAGIC); + mtk_w32(hw, MTK_RTC_PROT1, RTC_PROT1_MAGIC); + mtk_w32(hw, MTK_RTC_PROT2, RTC_PROT2_MAGIC); + mtk_w32(hw, MTK_RTC_PROT3, RTC_PROT3_MAGIC); + mtk_w32(hw, MTK_RTC_PROT4, RTC_PROT4_MAGIC); + mtk_rmw(hw, MTK_RTC_DEBNCE, RTC_DEBNCE_MASK, 0); + mtk_clr(hw, MTK_RTC_CTL, RTC_RC_STOP); +} + +static void mtk_rtc_get_alarm_or_time(struct mtk_rtc *hw, struct rtc_time *tm, + int time_alarm) +{ + u32 year, mon, mday, wday, hour, min, sec; + + /* + * Read again until all fields are not changed for all fields in the + * consistent state. + */ + do { + year = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_YEA)); + mon = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MON)); + wday = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOW)); + mday = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOM)); + hour = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_HOU)); + min = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MIN)); + sec = mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC)); + } while (year != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_YEA)) || + mon != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MON)) || + mday != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOM)) || + wday != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_DOW)) || + hour != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_HOU)) || + min != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_MIN)) || + sec != mtk_r32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC)) + ); + + tm->tm_sec = sec; + tm->tm_min = min; + tm->tm_hour = hour; + tm->tm_wday = wday; + tm->tm_mday = mday; + tm->tm_mon = mon - 1; + tm->tm_year = year; + tm->tm_year += 100; +} + +static void mtk_rtc_set_alarm_or_time(struct mtk_rtc *hw, struct rtc_time *tm, + int time_alarm) +{ + mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_YEA), tm->tm_year - 100); + mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_MON), tm->tm_mon + 1); + mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_DOW), tm->tm_wday); + mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_DOM), tm->tm_mday); + mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_HOU), tm->tm_hour); + mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_MIN), tm->tm_min); + mtk_w32(hw, MTK_RTC_TREG(time_alarm, MTK_SEC), tm->tm_sec); +} + +static irqreturn_t mtk_rtc_alarmirq(int irq, void *id) +{ + struct mtk_rtc *hw = (struct mtk_rtc *)id; + u32 irq_sta; + + /* Stop alarm also implicitly disable the alarm interrupt */ + mtk_w32(hw, MTK_RTC_AL_CTL, 0); + irq_sta = mtk_r32(hw, MTK_RTC_INT); + if (irq_sta & RTC_INT_AL_STA) { + rtc_update_irq(hw->rtc, 1, RTC_IRQF | RTC_AF); + + /* Ack alarm interrupt status */ + mtk_w32(hw, MTK_RTC_INT, RTC_INT_AL_STA); + return IRQ_HANDLED; + } + + return IRQ_NONE; +} + +static int mtk_rtc_gettime(struct device *dev, struct rtc_time *tm) +{ + struct mtk_rtc *hw = dev_get_drvdata(dev); + + mtk_rtc_get_alarm_or_time(hw, tm, MTK_TC); + + return rtc_valid_tm(tm); +} + +static int mtk_rtc_settime(struct device *dev, struct rtc_time *tm) +{ + struct mtk_rtc *hw = dev_get_drvdata(dev); + + /* Stop time counter before setting a new one*/ + mtk_set(hw, MTK_RTC_CTL, RTC_RC_STOP); + + /* Epoch == 1900 */ + if (tm->tm_year < 100 || tm->tm_year > 199) + return -EINVAL; + + mtk_rtc_set_alarm_or_time(hw, tm, MTK_TC); + + /* Restart the time counter */ + mtk_clr(hw, MTK_RTC_CTL, RTC_RC_STOP); + + return 0; +} + +static int mtk_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm) +{ + struct mtk_rtc *hw = dev_get_drvdata(dev); + struct rtc_time *alrm_tm = &wkalrm->time; + + mtk_rtc_get_alarm_or_time(hw, alrm_tm, MTK_AL); + + wkalrm->enabled = !!(mtk_r32(hw, MTK_RTC_AL_CTL) & RTC_AL_EN); + wkalrm->pending = !!(mtk_r32(hw, MTK_RTC_INT) & RTC_INT_AL_STA); + + return 0; +} + +static int mtk_rtc_setalarm(struct device *dev, struct rtc_wkalrm *wkalrm) +{ + struct mtk_rtc *hw = dev_get_drvdata(dev); + struct rtc_time *alrm_tm = &wkalrm->time; + + /* Epoch == 1900 */ + if (alrm_tm->tm_year < 100 || alrm_tm->tm_year > 199) + return -EINVAL; + + /* + * Stop the alarm also implicitly including disables interrupt before + * setting a new one. + */ + mtk_clr(hw, MTK_RTC_AL_CTL, RTC_AL_EN); + + /* + * Avoid contention between mtk_rtc_setalarm and IRQ handler so that + * disabling the interrupt and awaiting for pending IRQ handler to + * complete. + */ + synchronize_irq(hw->irq); + + mtk_rtc_set_alarm_or_time(hw, alrm_tm, MTK_AL); + + /* Restart the alarm with the new setup */ + mtk_w32(hw, MTK_RTC_AL_CTL, RTC_AL_ALL); + + return 0; +} + +static const struct rtc_class_ops mtk_rtc_ops = { + .read_time = mtk_rtc_gettime, + .set_time = mtk_rtc_settime, + .read_alarm = mtk_rtc_getalarm, + .set_alarm = mtk_rtc_setalarm, +}; + +static const struct of_device_id mtk_rtc_match[] = { + { .compatible = "mediatek,mt7622-rtc" }, + { .compatible = "mediatek,soc-rtc" }, + {}, +}; + +static int mtk_rtc_probe(struct platform_device *pdev) +{ + struct mtk_rtc *hw; + struct resource *res; + int ret; + + hw = devm_kzalloc(&pdev->dev, sizeof(*hw), GFP_KERNEL); + if (!hw) + return -ENOMEM; + + platform_set_drvdata(pdev, hw); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + hw->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(hw->base)) + return PTR_ERR(hw->base); + + hw->clk = devm_clk_get(&pdev->dev, "rtc"); + if (IS_ERR(hw->clk)) { + dev_err(&pdev->dev, "No clock\n"); + return PTR_ERR(hw->clk); + } + + ret = clk_prepare_enable(hw->clk); + if (ret) + return ret; + + hw->irq = platform_get_irq(pdev, 0); + if (hw->irq < 0) { + dev_err(&pdev->dev, "No IRQ resource\n"); + ret = hw->irq; + goto err; + } + + ret = devm_request_irq(&pdev->dev, hw->irq, mtk_rtc_alarmirq, + 0, dev_name(&pdev->dev), hw); + if (ret) { + dev_err(&pdev->dev, "Can't request IRQ\n"); + goto err; + } + + mtk_rtc_hw_init(hw); + + device_init_wakeup(&pdev->dev, true); + + hw->rtc = devm_rtc_device_register(&pdev->dev, pdev->name, + &mtk_rtc_ops, THIS_MODULE); + if (IS_ERR(hw->rtc)) { + ret = PTR_ERR(hw->rtc); + dev_err(&pdev->dev, "Unable to register device\n"); + goto err; + } + + dev_info(&pdev->dev, "MediaTek SoC based RTC enabled\n"); + + return 0; +err: + clk_disable_unprepare(hw->clk); + + return ret; +} + +static int mtk_rtc_remove(struct platform_device *pdev) +{ + struct mtk_rtc *hw = platform_get_drvdata(pdev); + + clk_disable_unprepare(hw->clk); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int mtk_rtc_suspend(struct device *dev) +{ + struct mtk_rtc *hw = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + enable_irq_wake(hw->irq); + + return 0; +} + +static int mtk_rtc_resume(struct device *dev) +{ + struct mtk_rtc *hw = dev_get_drvdata(dev); + + if (device_may_wakeup(dev)) + disable_irq_wake(hw->irq); + + return 0; +} + +static SIMPLE_DEV_PM_OPS(mtk_rtc_pm_ops, mtk_rtc_suspend, mtk_rtc_resume); + +#define MTK_RTC_PM_OPS (&mtk_rtc_pm_ops) +#else /* CONFIG_PM */ +#define MTK_RTC_PM_OPS NULL +#endif /* CONFIG_PM */ + +static struct platform_driver mtk_rtc_driver = { + .probe = mtk_rtc_probe, + .remove = mtk_rtc_remove, + .driver = { + .name = MTK_RTC_DEV, + .of_match_table = mtk_rtc_match, + .pm = MTK_RTC_PM_OPS, + }, +}; + +module_platform_driver(mtk_rtc_driver); + +MODULE_DESCRIPTION("MediaTek SoC based RTC Driver"); +MODULE_AUTHOR("Sean Wang <sean.wang@mediatek.com>"); +MODULE_LICENSE("GPL");