diff options
Diffstat (limited to 'drivers/rtc/rtc-jz4740.c')
| -rw-r--r-- | drivers/rtc/rtc-jz4740.c | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/drivers/rtc/rtc-jz4740.c b/drivers/rtc/rtc-jz4740.c index c2895cec56b4..33ccd73ee947 100644 --- a/drivers/rtc/rtc-jz4740.c +++ b/drivers/rtc/rtc-jz4740.c @@ -14,11 +14,13 @@ * */ +#include <linux/clk.h> #include <linux/io.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/of_device.h> #include <linux/platform_device.h> +#include <linux/reboot.h> #include <linux/rtc.h> #include <linux/slab.h> #include <linux/spinlock.h> @@ -28,6 +30,8 @@ #define JZ_REG_RTC_SEC_ALARM 0x08 #define JZ_REG_RTC_REGULATOR 0x0C #define JZ_REG_RTC_HIBERNATE 0x20 +#define JZ_REG_RTC_WAKEUP_FILTER 0x24 +#define JZ_REG_RTC_RESET_COUNTER 0x28 #define JZ_REG_RTC_SCRATCHPAD 0x34 /* The following are present on the jz4780 */ @@ -45,6 +49,9 @@ /* Magic value to enable writes on jz4780 */ #define JZ_RTC_WENR_MAGIC 0xA55A +#define JZ_RTC_WAKEUP_FILTER_MASK 0x0000FFE0 +#define JZ_RTC_RESET_COUNTER_MASK 0x00000FE0 + enum jz4740_rtc_type { ID_JZ4740, ID_JZ4780, @@ -55,12 +62,18 @@ struct jz4740_rtc { enum jz4740_rtc_type type; struct rtc_device *rtc; + struct clk *clk; int irq; spinlock_t lock; + + unsigned int min_wakeup_pin_assert_time; + unsigned int reset_pin_assert_time; }; +static struct device *dev_for_power_off; + static inline uint32_t jz4740_rtc_reg_read(struct jz4740_rtc *rtc, size_t reg) { return readl(rtc->base + reg); @@ -246,6 +259,46 @@ void jz4740_rtc_poweroff(struct device *dev) } EXPORT_SYMBOL_GPL(jz4740_rtc_poweroff); +static void jz4740_rtc_power_off(void) +{ + struct jz4740_rtc *rtc = dev_get_drvdata(dev_for_power_off); + unsigned long rtc_rate; + unsigned long wakeup_filter_ticks; + unsigned long reset_counter_ticks; + + clk_prepare_enable(rtc->clk); + + rtc_rate = clk_get_rate(rtc->clk); + + /* + * Set minimum wakeup pin assertion time: 100 ms. + * Range is 0 to 2 sec if RTC is clocked at 32 kHz. + */ + wakeup_filter_ticks = + (rtc->min_wakeup_pin_assert_time * rtc_rate) / 1000; + if (wakeup_filter_ticks < JZ_RTC_WAKEUP_FILTER_MASK) + wakeup_filter_ticks &= JZ_RTC_WAKEUP_FILTER_MASK; + else + wakeup_filter_ticks = JZ_RTC_WAKEUP_FILTER_MASK; + jz4740_rtc_reg_write(rtc, + JZ_REG_RTC_WAKEUP_FILTER, wakeup_filter_ticks); + + /* + * Set reset pin low-level assertion time after wakeup: 60 ms. + * Range is 0 to 125 ms if RTC is clocked at 32 kHz. + */ + reset_counter_ticks = (rtc->reset_pin_assert_time * rtc_rate) / 1000; + if (reset_counter_ticks < JZ_RTC_RESET_COUNTER_MASK) + reset_counter_ticks &= JZ_RTC_RESET_COUNTER_MASK; + else + reset_counter_ticks = JZ_RTC_RESET_COUNTER_MASK; + jz4740_rtc_reg_write(rtc, + JZ_REG_RTC_RESET_COUNTER, reset_counter_ticks); + + jz4740_rtc_poweroff(dev_for_power_off); + machine_halt(); +} + static const struct of_device_id jz4740_rtc_of_match[] = { { .compatible = "ingenic,jz4740-rtc", .data = (void *)ID_JZ4740 }, { .compatible = "ingenic,jz4780-rtc", .data = (void *)ID_JZ4780 }, @@ -262,6 +315,7 @@ static int jz4740_rtc_probe(struct platform_device *pdev) const struct platform_device_id *id = platform_get_device_id(pdev); const struct of_device_id *of_id = of_match_device( jz4740_rtc_of_match, &pdev->dev); + struct device_node *np = pdev->dev.of_node; rtc = devm_kzalloc(&pdev->dev, sizeof(*rtc), GFP_KERNEL); if (!rtc) @@ -283,6 +337,12 @@ static int jz4740_rtc_probe(struct platform_device *pdev) if (IS_ERR(rtc->base)) return PTR_ERR(rtc->base); + rtc->clk = devm_clk_get(&pdev->dev, "rtc"); + if (IS_ERR(rtc->clk)) { + dev_err(&pdev->dev, "Failed to get RTC clock\n"); + return PTR_ERR(rtc->clk); + } + spin_lock_init(&rtc->lock); platform_set_drvdata(pdev, rtc); @@ -314,6 +374,27 @@ static int jz4740_rtc_probe(struct platform_device *pdev) } } + if (np && of_device_is_system_power_controller(np)) { + if (!pm_power_off) { + /* Default: 60ms */ + rtc->reset_pin_assert_time = 60; + of_property_read_u32(np, "reset-pin-assert-time-ms", + &rtc->reset_pin_assert_time); + + /* Default: 100ms */ + rtc->min_wakeup_pin_assert_time = 100; + of_property_read_u32(np, + "min-wakeup-pin-assert-time-ms", + &rtc->min_wakeup_pin_assert_time); + + dev_for_power_off = &pdev->dev; + pm_power_off = jz4740_rtc_power_off; + } else { + dev_warn(&pdev->dev, + "Poweroff handler already present!\n"); + } + } + return 0; } |