| Message ID | 20211115113208.237296-1-jonathanh@nvidia.com |
|---|---|
| State | Changes Requested |
| Headers | show |
| Series | soc/tegra: pmc: Add reboot notifier | expand |
15.11.2021 14:32, Jon Hunter пишет: > -static int tegra_pmc_restart_notify(struct notifier_block *this, > - unsigned long action, void *data) > +static void tegra_pmc_program_reboot_reason(const char *cmd) > { > - const char *cmd = data; > u32 value; > > + if (!cmd) > + return; There is no explanation of this change in the commit message. Previously scratch register was cleared if command is NULL, now it's not. Why?
On 18/11/2021 19:13, Dmitry Osipenko wrote: > 15.11.2021 14:32, Jon Hunter пишет: >> -static int tegra_pmc_restart_notify(struct notifier_block *this, >> - unsigned long action, void *data) >> +static void tegra_pmc_program_reboot_reason(const char *cmd) >> { >> - const char *cmd = data; >> u32 value; >> >> + if (!cmd) >> + return; > > There is no explanation of this change in the commit message. Previously > scratch register was cleared if command is NULL, now it's not. Why? No reason, just an oversight on my part. I can change this back to keep the behaviour the same. Jon
22.11.2021 15:12, Jon Hunter пишет: > > On 18/11/2021 19:13, Dmitry Osipenko wrote: >> 15.11.2021 14:32, Jon Hunter пишет: >>> -static int tegra_pmc_restart_notify(struct notifier_block *this, >>> - unsigned long action, void *data) >>> +static void tegra_pmc_program_reboot_reason(const char *cmd) >>> { >>> - const char *cmd = data; >>> u32 value; >>> + if (!cmd) >>> + return; >> >> There is no explanation of this change in the commit message. Previously >> scratch register was cleared if command is NULL, now it's not. Why? > > > No reason, just an oversight on my part. I can change this back to keep > the behaviour the same. Alright, I'd expect bootloader to clear the register, although perhaps there could be a reason why kernel needs to clear it since all downstream kernels do it. BTW, this patch is also needed in order to support restarting to bootloader using PMIC's restart handler, which should become a thing for some T30 devices soon. Although, will need to double check whether scratch reg state retains after a full SoC power-cycle, but I assume it should retain since RTC domain should stay always-on.
diff --git a/drivers/soc/tegra/pmc.c b/drivers/soc/tegra/pmc.c index 575d6d5b4294..19357ad9f46a 100644 --- a/drivers/soc/tegra/pmc.c +++ b/drivers/soc/tegra/pmc.c @@ -1064,27 +1064,47 @@ int tegra_pmc_cpu_remove_clamping(unsigned int cpuid) return tegra_powergate_remove_clamping(id); } -static int tegra_pmc_restart_notify(struct notifier_block *this, - unsigned long action, void *data) +static void tegra_pmc_program_reboot_reason(const char *cmd) { - const char *cmd = data; u32 value; + if (!cmd) + return; + value = tegra_pmc_scratch_readl(pmc, pmc->soc->regs->scratch0); value &= ~PMC_SCRATCH0_MODE_MASK; - if (cmd) { - if (strcmp(cmd, "recovery") == 0) - value |= PMC_SCRATCH0_MODE_RECOVERY; + if (strcmp(cmd, "recovery") == 0) + value |= PMC_SCRATCH0_MODE_RECOVERY; - if (strcmp(cmd, "bootloader") == 0) - value |= PMC_SCRATCH0_MODE_BOOTLOADER; + if (strcmp(cmd, "bootloader") == 0) + value |= PMC_SCRATCH0_MODE_BOOTLOADER; - if (strcmp(cmd, "forced-recovery") == 0) - value |= PMC_SCRATCH0_MODE_RCM; - } + if (strcmp(cmd, "forced-recovery") == 0) + value |= PMC_SCRATCH0_MODE_RCM; tegra_pmc_scratch_writel(pmc, value, pmc->soc->regs->scratch0); +} + +static int tegra_pmc_reboot_notify(struct notifier_block *this, + unsigned long action, void *data) +{ + if (action == SYS_RESTART) + tegra_pmc_program_reboot_reason(data); + + return NOTIFY_DONE; +} + +static struct notifier_block tegra_pmc_reboot_notifier = { + .notifier_call = tegra_pmc_reboot_notify, +}; + +static int tegra_pmc_restart_notify(struct notifier_block *this, + unsigned long action, void *data) +{ + u32 value; + + tegra_pmc_program_reboot_reason(data); /* reset everything but PMC_SCRATCH0 and PMC_RST_STATUS */ value = tegra_pmc_readl(pmc, PMC_CNTRL); @@ -2890,6 +2910,14 @@ static int tegra_pmc_probe(struct platform_device *pdev) goto cleanup_sysfs; } + err = devm_register_reboot_notifier(&pdev->dev, + &tegra_pmc_reboot_notifier); + if (err) { + dev_err(&pdev->dev, "unable to register reboot notifier, %d\n", + err); + goto cleanup_debugfs; + } + err = register_restart_handler(&tegra_pmc_restart_handler); if (err) { dev_err(&pdev->dev, "unable to register restart handler, %d\n",
The Tegra PMC driver implements a restart handler that supports Tegra specific reboot commands such as placing the device into 'recovery' mode in order to reprogram the platform. This is accomplished by setting the appropriate bit in the PMC scratch0 register prior to rebooting the platform. For Tegra platforms that support PSCI or EFI, the default Tegra restart handler is not called and the PSCI or EFI restart handler is called instead. Hence, for Tegra platforms that support PSCI or EFI, the Tegra specific reboot commands do not currently work. Fix this by moving the code that programs the PMC scratch0 register into a separate reboot notifier that will always be called on reboot. Signed-off-by: Jon Hunter <jonathanh@nvidia.com> --- drivers/soc/tegra/pmc.c | 50 ++++++++++++++++++++++++++++++++--------- 1 file changed, 39 insertions(+), 11 deletions(-)