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- From 94119ec772b375c3b94d83b2ff61a9d447d8083a Mon Sep 17 00:00:00 2001
- From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <[email protected]>
- Date: Fri, 7 Oct 2016 16:50:59 +0200
- Subject: [PATCH] watchdog: bcm2835: Support setting reboot partition
- MIME-Version: 1.0
- Content-Type: text/plain; charset=UTF-8
- Content-Transfer-Encoding: 8bit
- The Raspberry Pi firmware looks at the RSTS register to know which
- partition to boot from. The reboot syscall command
- LINUX_REBOOT_CMD_RESTART2 supports passing in a string argument.
- Add support for passing in a partition number 0..63 to boot from.
- Partition 63 is a special partiton indicating halt.
- If the partition doesn't exist, the firmware falls back to partition 0.
- Signed-off-by: Noralf Trønnes <[email protected]>
- ---
- drivers/watchdog/bcm2835_wdt.c | 49 +++++++++++++++++++---------------
- 1 file changed, 27 insertions(+), 22 deletions(-)
- --- a/drivers/watchdog/bcm2835_wdt.c
- +++ b/drivers/watchdog/bcm2835_wdt.c
- @@ -32,13 +32,7 @@
- #define PM_RSTC_WRCFG_SET 0x00000030
- #define PM_RSTC_WRCFG_FULL_RESET 0x00000020
- #define PM_RSTC_RESET 0x00000102
- -
- -/*
- - * The Raspberry Pi firmware uses the RSTS register to know which partition
- - * to boot from. The partition value is spread into bits 0, 2, 4, 6, 8, 10.
- - * Partition 63 is a special partition used by the firmware to indicate halt.
- - */
- -#define PM_RSTS_RASPBERRYPI_HALT 0x555
- +#define PM_RSTS_PARTITION_CLR 0xfffffaaa
-
- #define SECS_TO_WDOG_TICKS(x) ((x) << 16)
- #define WDOG_TICKS_TO_SECS(x) ((x) >> 16)
- @@ -98,9 +92,24 @@ static unsigned int bcm2835_wdt_get_time
- return WDOG_TICKS_TO_SECS(ret & PM_WDOG_TIME_SET);
- }
-
- -static void __bcm2835_restart(struct bcm2835_wdt *wdt)
- +/*
- + * The Raspberry Pi firmware uses the RSTS register to know which partiton
- + * to boot from. The partiton value is spread into bits 0, 2, 4, 6, 8, 10.
- + * Partiton 63 is a special partition used by the firmware to indicate halt.
- + */
- +
- +static void __bcm2835_restart(struct bcm2835_wdt *wdt, u8 partition)
- {
- - u32 val;
- + u32 val, rsts;
- +
- + rsts = (partition & BIT(0)) | ((partition & BIT(1)) << 1) |
- + ((partition & BIT(2)) << 2) | ((partition & BIT(3)) << 3) |
- + ((partition & BIT(4)) << 4) | ((partition & BIT(5)) << 5);
- +
- + val = readl_relaxed(wdt->base + PM_RSTS);
- + val &= PM_RSTS_PARTITION_CLR;
- + val |= PM_PASSWORD | rsts;
- + writel_relaxed(val, wdt->base + PM_RSTS);
-
- /* use a timeout of 10 ticks (~150us) */
- writel_relaxed(10 | PM_PASSWORD, wdt->base + PM_WDOG);
- @@ -118,7 +127,13 @@ static int bcm2835_restart(struct watchd
- {
- struct bcm2835_wdt *wdt = watchdog_get_drvdata(wdog);
-
- - __bcm2835_restart(wdt);
- + unsigned long long val;
- + u8 partition = 0;
- +
- + if (data && !kstrtoull(data, 0, &val) && val <= 63)
- + partition = val;
- +
- + __bcm2835_restart(wdt, partition);
-
- return 0;
- }
- @@ -153,19 +168,9 @@ static struct watchdog_device bcm2835_wd
- static void bcm2835_power_off(void)
- {
- struct bcm2835_wdt *wdt = bcm2835_power_off_wdt;
- - u32 val;
- -
- - /*
- - * We set the watchdog hard reset bit here to distinguish this reset
- - * from the normal (full) reset. bootcode.bin will not reboot after a
- - * hard reset.
- - */
- - val = readl_relaxed(wdt->base + PM_RSTS);
- - val |= PM_PASSWORD | PM_RSTS_RASPBERRYPI_HALT;
- - writel_relaxed(val, wdt->base + PM_RSTS);
-
- - /* Continue with normal reset mechanism */
- - __bcm2835_restart(wdt);
- + /* Partition 63 tells the firmware that this is a halt */
- + __bcm2835_restart(wdt, 63);
- }
-
- static int bcm2835_wdt_probe(struct platform_device *pdev)
|
