Re: [PATCH v5 02/15] clk: at91: pmc: execute suspend/resume only for backup mode
From: Nicolas Ferre <nicolas.ferre@microchip.com>
Date: 2021-10-15 07:51:57
Also in:
linux-clk, lkml
On 11/10/2021 at 13:27, Claudiu Beznea wrote:
Before going to backup mode architecture specific PM code sets the first word in securam (file arch/arm/mach-at91/pm.c, function at91_pm_begin()). Thus take this into account when suspending/resuming clocks. This will avoid executing unnecessary instructions when suspending to non backup modes. Signed-off-by: Claudiu Beznea <redacted>
Ok to do it like this: Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
quoted hunk ↗ jump to hunk
--- drivers/clk/at91/pmc.c | 39 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 39 insertions(+)diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c index b2806946a77a..517973062719 100644 --- a/drivers/clk/at91/pmc.c +++ b/drivers/clk/at91/pmc.c@@ -8,6 +8,7 @@ #include <linux/clkdev.h> #include <linux/clk/at91_pmc.h> #include <linux/of.h> +#include <linux/of_address.h> #include <linux/mfd/syscon.h> #include <linux/platform_device.h> #include <linux/regmap.h>@@ -110,13 +111,35 @@ struct pmc_data *pmc_data_allocate(unsigned int ncore, unsigned int nsystem, } #ifdef CONFIG_PM + +/* Address in SECURAM that say if we suspend to backup mode. */ +static void __iomem *at91_pmc_backup_suspend; + static int at91_pmc_suspend(void) { + unsigned int backup; + + if (!at91_pmc_backup_suspend) + return 0; + + backup = readl_relaxed(at91_pmc_backup_suspend); + if (!backup) + return 0; + return clk_save_context(); } static void at91_pmc_resume(void) { + unsigned int backup; + + if (!at91_pmc_backup_suspend) + return; + + backup = readl_relaxed(at91_pmc_backup_suspend); + if (!backup) + return; + clk_restore_context(); }@@ -144,6 +167,22 @@ static int __init pmc_register_ops(void) } of_node_put(np); + np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-securam"); + if (!np) + return -ENODEV; + + if (!of_device_is_available(np)) { + of_node_put(np); + return -ENODEV; + } + of_node_put(np); + + at91_pmc_backup_suspend = of_iomap(np, 0); + if (!at91_pmc_backup_suspend) { + pr_warn("%s(): unable to map securam\n", __func__); + return -ENOMEM; + } + register_syscore_ops(&pmc_syscore_ops); return 0;
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