diff options
| author | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2017-05-12 20:22:51 +0200 |
|---|---|---|
| committer | Daniel Lezcano <daniel.lezcano@linaro.org> | 2017-06-14 12:02:31 +0200 |
| commit | 2a515e5d7c52d5cf1e9153cb03efa133e3459c88 (patch) | |
| tree | 4a6cc063a655293586207a8c9220ff99d591eaa7 | |
| parent | 740e237add571a125f1c2a110ba6aa77db7d2c69 (diff) | |
| download | linux-2a515e5d7c52d5cf1e9153cb03efa133e3459c88.tar.bz2 | |
clocksource/drivers/tcb_clksrc: Save timer context on suspend/resume
On sama5d2, power to the core may be cut while entering suspend mode. It is
necessary to save and restore the TCB registers.
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
| -rw-r--r-- | drivers/clocksource/tcb_clksrc.c | 51 |
1 files changed, 51 insertions, 0 deletions
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c index d4ca9962a759..828729c70a0c 100644 --- a/drivers/clocksource/tcb_clksrc.c +++ b/drivers/clocksource/tcb_clksrc.c @@ -9,6 +9,7 @@ #include <linux/ioport.h> #include <linux/io.h> #include <linux/platform_device.h> +#include <linux/syscore_ops.h> #include <linux/atmel_tc.h> @@ -40,6 +41,14 @@ */ static void __iomem *tcaddr; +static struct +{ + u32 cmr; + u32 imr; + u32 rc; + bool clken; +} tcb_cache[3]; +static u32 bmr_cache; static u64 tc_get_cycles(struct clocksource *cs) { @@ -61,12 +70,54 @@ static u64 tc_get_cycles32(struct clocksource *cs) return __raw_readl(tcaddr + ATMEL_TC_REG(0, CV)); } +void tc_clksrc_suspend(struct clocksource *cs) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(tcb_cache); i++) { + tcb_cache[i].cmr = readl(tcaddr + ATMEL_TC_REG(i, CMR)); + tcb_cache[i].imr = readl(tcaddr + ATMEL_TC_REG(i, IMR)); + tcb_cache[i].rc = readl(tcaddr + ATMEL_TC_REG(i, RC)); + tcb_cache[i].clken = !!(readl(tcaddr + ATMEL_TC_REG(i, SR)) & + ATMEL_TC_CLKSTA); + } + + bmr_cache = readl(tcaddr + ATMEL_TC_BMR); +} + +void tc_clksrc_resume(struct clocksource *cs) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(tcb_cache); i++) { + /* Restore registers for the channel, RA and RB are not used */ + writel(tcb_cache[i].cmr, tcaddr + ATMEL_TC_REG(i, CMR)); + writel(tcb_cache[i].rc, tcaddr + ATMEL_TC_REG(i, RC)); + writel(0, tcaddr + ATMEL_TC_REG(i, RA)); + writel(0, tcaddr + ATMEL_TC_REG(i, RB)); + /* Disable all the interrupts */ + writel(0xff, tcaddr + ATMEL_TC_REG(i, IDR)); + /* Reenable interrupts that were enabled before suspending */ + writel(tcb_cache[i].imr, tcaddr + ATMEL_TC_REG(i, IER)); + /* Start the clock if it was used */ + if (tcb_cache[i].clken) + writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(i, CCR)); + } + + /* Dual channel, chain channels */ + writel(bmr_cache, tcaddr + ATMEL_TC_BMR); + /* Finally, trigger all the channels*/ + writel(ATMEL_TC_SYNC, tcaddr + ATMEL_TC_BCR); +} + static struct clocksource clksrc = { .name = "tcb_clksrc", .rating = 200, .read = tc_get_cycles, .mask = CLOCKSOURCE_MASK(32), .flags = CLOCK_SOURCE_IS_CONTINUOUS, + .suspend = tc_clksrc_suspend, + .resume = tc_clksrc_resume, }; #ifdef CONFIG_GENERIC_CLOCKEVENTS |