From: Thierry Reding <thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> To: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org> Cc: Alexandre Courbot <gnurou-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>, linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Subject: [PATCH] ARM: tegra: Support reboot modes Date: Tue, 6 May 2014 17:04:11 +0200 [thread overview] Message-ID: <1399388651-12819-1-git-send-email-thierry.reding@gmail.com> (raw) From: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> The boot ROM on Tegra SoCs supports booting into forced recovery mode (RCM) by setting a bit in the PMC scratch register 0. Similarily, the Android bootloader examines some of the bits in this register to disable autoboot or enter recovery mode. Support these modes by setting the corresponding bits depending on the specified reboot command (forced-recovery, bootloader, recovery). Recent systemd-based distributions allow this to be specified using an optional argument to the reboot command. Signed-off-by: Thierry Reding <treding-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> --- arch/arm/mach-tegra/pmc.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/arch/arm/mach-tegra/pmc.c b/arch/arm/mach-tegra/pmc.c index fb7920201ab4..7c7123e7557b 100644 --- a/arch/arm/mach-tegra/pmc.c +++ b/arch/arm/mach-tegra/pmc.c @@ -41,6 +41,14 @@ #define PMC_REMOVE_CLAMPING 0x34 #define PMC_PWRGATE_STATUS 0x38 +#define PMC_SCRATCH0 0x50 +#define PMC_SCRATCH0_MODE_RECOVERY (1 << 31) +#define PMC_SCRATCH0_MODE_BOOTLOADER (1 << 30) +#define PMC_SCRATCH0_MODE_RCM (1 << 1) +#define PMC_SCRATCH0_MODE_MASK (PMC_SCRATCH0_MODE_RECOVERY | \ + PMC_SCRATCH0_MODE_BOOTLOADER | \ + PMC_SCRATCH0_MODE_RCM) + #define PMC_CPUPWRGOOD_TIMER 0xc8 #define PMC_CPUPWROFF_TIMER 0xcc @@ -165,6 +173,22 @@ void tegra_pmc_restart(enum reboot_mode mode, const char *cmd) { u32 val; + val = tegra_pmc_readl(PMC_SCRATCH0); + val &= ~PMC_SCRATCH0_MODE_MASK; + + if (cmd) { + if (strcmp(cmd, "recovery") == 0) + val |= PMC_SCRATCH0_MODE_RECOVERY; + + if (strcmp(cmd, "bootloader") == 0) + val |= PMC_SCRATCH0_MODE_BOOTLOADER; + + if (strcmp(cmd, "forced-recovery") == 0) + val |= PMC_SCRATCH0_MODE_RCM; + } + + tegra_pmc_writel(val, PMC_SCRATCH0); + val = tegra_pmc_readl(0); val |= 0x10; tegra_pmc_writel(val, 0); -- 1.9.2
WARNING: multiple messages have this Message-ID (diff)
From: thierry.reding@gmail.com (Thierry Reding) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH] ARM: tegra: Support reboot modes Date: Tue, 6 May 2014 17:04:11 +0200 [thread overview] Message-ID: <1399388651-12819-1-git-send-email-thierry.reding@gmail.com> (raw) From: Thierry Reding <treding@nvidia.com> The boot ROM on Tegra SoCs supports booting into forced recovery mode (RCM) by setting a bit in the PMC scratch register 0. Similarily, the Android bootloader examines some of the bits in this register to disable autoboot or enter recovery mode. Support these modes by setting the corresponding bits depending on the specified reboot command (forced-recovery, bootloader, recovery). Recent systemd-based distributions allow this to be specified using an optional argument to the reboot command. Signed-off-by: Thierry Reding <treding@nvidia.com> --- arch/arm/mach-tegra/pmc.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/arch/arm/mach-tegra/pmc.c b/arch/arm/mach-tegra/pmc.c index fb7920201ab4..7c7123e7557b 100644 --- a/arch/arm/mach-tegra/pmc.c +++ b/arch/arm/mach-tegra/pmc.c @@ -41,6 +41,14 @@ #define PMC_REMOVE_CLAMPING 0x34 #define PMC_PWRGATE_STATUS 0x38 +#define PMC_SCRATCH0 0x50 +#define PMC_SCRATCH0_MODE_RECOVERY (1 << 31) +#define PMC_SCRATCH0_MODE_BOOTLOADER (1 << 30) +#define PMC_SCRATCH0_MODE_RCM (1 << 1) +#define PMC_SCRATCH0_MODE_MASK (PMC_SCRATCH0_MODE_RECOVERY | \ + PMC_SCRATCH0_MODE_BOOTLOADER | \ + PMC_SCRATCH0_MODE_RCM) + #define PMC_CPUPWRGOOD_TIMER 0xc8 #define PMC_CPUPWROFF_TIMER 0xcc @@ -165,6 +173,22 @@ void tegra_pmc_restart(enum reboot_mode mode, const char *cmd) { u32 val; + val = tegra_pmc_readl(PMC_SCRATCH0); + val &= ~PMC_SCRATCH0_MODE_MASK; + + if (cmd) { + if (strcmp(cmd, "recovery") == 0) + val |= PMC_SCRATCH0_MODE_RECOVERY; + + if (strcmp(cmd, "bootloader") == 0) + val |= PMC_SCRATCH0_MODE_BOOTLOADER; + + if (strcmp(cmd, "forced-recovery") == 0) + val |= PMC_SCRATCH0_MODE_RCM; + } + + tegra_pmc_writel(val, PMC_SCRATCH0); + val = tegra_pmc_readl(0); val |= 0x10; tegra_pmc_writel(val, 0); -- 1.9.2
next reply other threads:[~2014-05-06 15:04 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-05-06 15:04 Thierry Reding [this message] 2014-05-06 15:04 ` [PATCH] ARM: tegra: Support reboot modes Thierry Reding [not found] ` <1399388651-12819-1-git-send-email-thierry.reding-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> 2014-05-07 3:46 ` Alexandre Courbot 2014-05-07 3:46 ` Alexandre Courbot 2014-05-07 15:58 ` Stephen Warren 2014-05-07 15:58 ` Stephen Warren
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