125 lines
4.3 KiB
Diff
125 lines
4.3 KiB
Diff
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From 259f169ef05f12bc7fed007befc11ed6c66dd9c8 Mon Sep 17 00:00:00 2001
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From: =?UTF-8?q?Noralf=20Tr=C3=B8nnes?= <noralf@tronnes.org>
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Date: Fri, 7 Oct 2016 16:50:59 +0200
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Subject: [PATCH] watchdog: bcm2835: Support setting reboot partition
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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The Raspberry Pi firmware looks at the RSTS register to know which
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partition to boot from. The reboot syscall command
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LINUX_REBOOT_CMD_RESTART2 supports passing in a string argument.
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Add support for passing in a partition number 0..63 to boot from.
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Partition 63 is a special partiton indicating halt.
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If the partition doesn't exist, the firmware falls back to partition 0.
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Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
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---
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drivers/watchdog/bcm2835_wdt.c | 61 +++++++++++++++++++++++++-----------------
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1 file changed, 36 insertions(+), 25 deletions(-)
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--- a/drivers/watchdog/bcm2835_wdt.c
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+++ b/drivers/watchdog/bcm2835_wdt.c
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@@ -35,13 +35,7 @@
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#define PM_RSTC_WRCFG_SET 0x00000030
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#define PM_RSTC_WRCFG_FULL_RESET 0x00000020
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#define PM_RSTC_RESET 0x00000102
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-
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-/*
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- * The Raspberry Pi firmware uses the RSTS register to know which partiton
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- * to boot from. The partiton value is spread into bits 0, 2, 4, 6, 8, 10.
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- * Partiton 63 is a special partition used by the firmware to indicate halt.
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- */
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-#define PM_RSTS_RASPBERRYPI_HALT 0x555
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+#define PM_RSTS_PARTITION_CLR 0xfffffaaa
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#define SECS_TO_WDOG_TICKS(x) ((x) << 16)
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#define WDOG_TICKS_TO_SECS(x) ((x) >> 16)
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@@ -111,15 +105,28 @@ static struct watchdog_device bcm2835_wd
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.timeout = WDOG_TICKS_TO_SECS(PM_WDOG_TIME_SET),
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};
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-static int
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-bcm2835_restart(struct notifier_block *this, unsigned long mode, void *cmd)
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+/*
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+ * The Raspberry Pi firmware uses the RSTS register to know which partiton
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+ * to boot from. The partiton value is spread into bits 0, 2, 4, 6, 8, 10.
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+ * Partiton 63 is a special partition used by the firmware to indicate halt.
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+ */
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+
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+static void bcm2835_restart(struct bcm2835_wdt *wdt, u8 partition)
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{
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- struct bcm2835_wdt *wdt = container_of(this, struct bcm2835_wdt,
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- restart_handler);
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- u32 val;
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+ u32 val, rsts;
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+
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+ rsts = (partition & BIT(0)) | ((partition & BIT(1)) << 1) |
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+ ((partition & BIT(2)) << 2) | ((partition & BIT(3)) << 3) |
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+ ((partition & BIT(4)) << 4) | ((partition & BIT(5)) << 5);
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+
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+ val = readl_relaxed(wdt->base + PM_RSTS);
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+ val &= PM_RSTS_PARTITION_CLR;
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+ val |= PM_PASSWORD | rsts;
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+ writel_relaxed(val, wdt->base + PM_RSTS);
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/* use a timeout of 10 ticks (~150us) */
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writel_relaxed(10 | PM_PASSWORD, wdt->base + PM_WDOG);
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+
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val = readl_relaxed(wdt->base + PM_RSTC);
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val &= PM_RSTC_WRCFG_CLR;
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val |= PM_PASSWORD | PM_RSTC_WRCFG_FULL_RESET;
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@@ -127,6 +134,20 @@ bcm2835_restart(struct notifier_block *t
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/* No sleeping, possibly atomic. */
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mdelay(1);
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+}
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+
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+static int bcm2835_restart_notifier_call(struct notifier_block *this,
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+ unsigned long mode, void *cmd)
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+{
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+ struct bcm2835_wdt *wdt = container_of(this, struct bcm2835_wdt,
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+ restart_handler);
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+ unsigned long long val;
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+ u8 partition = 0;
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+
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+ if (cmd && !kstrtoull(cmd, 0, &val) && val <= 63)
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+ partition = val;
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+
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+ bcm2835_restart(wdt, partition);
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return 0;
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}
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@@ -142,19 +163,9 @@ static void bcm2835_power_off(void)
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of_find_compatible_node(NULL, NULL, "brcm,bcm2835-pm-wdt");
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struct platform_device *pdev = of_find_device_by_node(np);
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struct bcm2835_wdt *wdt = platform_get_drvdata(pdev);
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- u32 val;
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-
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- /*
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- * We set the watchdog hard reset bit here to distinguish this reset
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- * from the normal (full) reset. bootcode.bin will not reboot after a
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- * hard reset.
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- */
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- val = readl_relaxed(wdt->base + PM_RSTS);
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- val |= PM_PASSWORD | PM_RSTS_RASPBERRYPI_HALT;
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- writel_relaxed(val, wdt->base + PM_RSTS);
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- /* Continue with normal reset mechanism */
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- bcm2835_restart(&wdt->restart_handler, REBOOT_HARD, NULL);
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+ /* Partition 63 tells the firmware that this is a halt */
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+ bcm2835_restart(wdt, 63);
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}
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static int bcm2835_wdt_probe(struct platform_device *pdev)
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@@ -188,7 +199,7 @@ static int bcm2835_wdt_probe(struct plat
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return err;
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}
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- wdt->restart_handler.notifier_call = bcm2835_restart;
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+ wdt->restart_handler.notifier_call = bcm2835_restart_notifier_call;
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wdt->restart_handler.priority = 128;
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register_restart_handler(&wdt->restart_handler);
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if (pm_power_off == NULL)
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