diff options
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-stmp3xxx.c | 64 |
1 files changed, 64 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-stmp3xxx.c b/drivers/rtc/rtc-stmp3xxx.c index b2a8ed99b2bf..98f0d3c30738 100644 --- a/drivers/rtc/rtc-stmp3xxx.c +++ b/drivers/rtc/rtc-stmp3xxx.c @@ -27,6 +27,8 @@ #include <linux/slab.h> #include <linux/of_device.h> #include <linux/of.h> +#include <linux/stmp_device.h> +#include <linux/stmp3xxx_rtc_wdt.h> #include <mach/common.h> @@ -36,6 +38,7 @@ #define STMP3XXX_RTC_CTRL_ALARM_IRQ_EN 0x00000001 #define STMP3XXX_RTC_CTRL_ONEMSEC_IRQ_EN 0x00000002 #define STMP3XXX_RTC_CTRL_ALARM_IRQ 0x00000004 +#define STMP3XXX_RTC_CTRL_WATCHDOGEN 0x00000010 #define STMP3XXX_RTC_STAT 0x10 #define STMP3XXX_RTC_STAT_STALE_SHIFT 16 @@ -45,6 +48,8 @@ #define STMP3XXX_RTC_ALARM 0x40 +#define STMP3XXX_RTC_WATCHDOG 0x50 + #define STMP3XXX_RTC_PERSISTENT0 0x60 #define STMP3XXX_RTC_PERSISTENT0_SET 0x64 #define STMP3XXX_RTC_PERSISTENT0_CLR 0x68 @@ -52,12 +57,70 @@ #define STMP3XXX_RTC_PERSISTENT0_ALARM_EN 0x00000004 #define STMP3XXX_RTC_PERSISTENT0_ALARM_WAKE 0x00000080 +#define STMP3XXX_RTC_PERSISTENT1 0x70 +/* missing bitmask in headers */ +#define STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER 0x80000000 + struct stmp3xxx_rtc_data { struct rtc_device *rtc; void __iomem *io; int irq_alarm; }; +#if IS_ENABLED(CONFIG_STMP3XXX_RTC_WATCHDOG) +/** + * stmp3xxx_wdt_set_timeout - configure the watchdog inside the STMP3xxx RTC + * @dev: the parent device of the watchdog (= the RTC) + * @timeout: the desired value for the timeout register of the watchdog. + * 0 disables the watchdog + * + * The watchdog needs one register and two bits which are in the RTC domain. + * To handle the resource conflict, the RTC driver will create another + * platform_device for the watchdog driver as a child of the RTC device. + * The watchdog driver is passed the below accessor function via platform_data + * to configure the watchdog. Locking is not needed because accessing SET/CLR + * registers is atomic. + */ + +static void stmp3xxx_wdt_set_timeout(struct device *dev, u32 timeout) +{ + struct stmp3xxx_rtc_data *rtc_data = dev_get_drvdata(dev); + + if (timeout) { + writel(timeout, rtc_data->io + STMP3XXX_RTC_WATCHDOG); + writel(STMP3XXX_RTC_CTRL_WATCHDOGEN, + rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_SET); + writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER, + rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_SET); + } else { + writel(STMP3XXX_RTC_CTRL_WATCHDOGEN, + rtc_data->io + STMP3XXX_RTC_CTRL + STMP_OFFSET_REG_CLR); + writel(STMP3XXX_RTC_PERSISTENT1_FORCE_UPDATER, + rtc_data->io + STMP3XXX_RTC_PERSISTENT1 + STMP_OFFSET_REG_CLR); + } +} + +static struct stmp3xxx_wdt_pdata wdt_pdata = { + .wdt_set_timeout = stmp3xxx_wdt_set_timeout, +}; + +static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev) +{ + struct platform_device *wdt_pdev = + platform_device_alloc("stmp3xxx_rtc_wdt", rtc_pdev->id); + + if (wdt_pdev) { + wdt_pdev->dev.parent = &rtc_pdev->dev; + wdt_pdev->dev.platform_data = &wdt_pdata; + platform_device_add(wdt_pdev); + } +} +#else +static void stmp3xxx_wdt_register(struct platform_device *rtc_pdev) +{ +} +#endif /* CONFIG_STMP3XXX_RTC_WATCHDOG */ + static void stmp3xxx_wait_time(struct stmp3xxx_rtc_data *rtc_data) { /* @@ -233,6 +296,7 @@ static int stmp3xxx_rtc_probe(struct platform_device *pdev) goto out_irq_alarm; } + stmp3xxx_wdt_register(pdev); return 0; out_irq_alarm: |