[PATCH v3 02/17] clk: at91: pmc: execute suspend/resume only for backup mode
From: Claudiu Beznea <hidden>
Date: 2021-09-17 12:06:56
Also in:
linux-clk, lkml
Subsystem:
common clk framework, the rest · Maintainers:
Michael Turquette, Stephen Boyd, Linus Torvalds
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. Also this commit changed the postcore_initcall() with subsys_initcall() to be able to execute of_find_compatible_node() since this was not available at the moment of postcore_initcall(). This should not alter the tcb_clksrc since the changes are related to clocks suspend/resume procedure that will be executed at the user space request, thus long ago after subsys_initcall(). Signed-off-by: Claudiu Beznea <redacted> --- drivers/clk/at91/pmc.c | 49 ++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 47 insertions(+), 2 deletions(-)
diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c
index b2806946a77a..58e9c088cb22 100644
--- a/drivers/clk/at91/pmc.c
+++ b/drivers/clk/at91/pmc.c@@ -8,6 +8,8 @@ #include <linux/clkdev.h> #include <linux/clk/at91_pmc.h> #include <linux/of.h> +#include <linux/of_address.h> +#include <linux/of_platform.h> #include <linux/mfd/syscon.h> #include <linux/platform_device.h> #include <linux/regmap.h>
@@ -110,13 +112,35 @@ 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 = *(unsigned int *)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 = *(unsigned int *)at91_pmc_backup_suspend; + if (!backup) + return; + clk_restore_context(); }
@@ -132,6 +156,7 @@ static const struct of_device_id sama5d2_pmc_dt_ids[] = { static int __init pmc_register_ops(void) { + struct platform_device *pdev; struct device_node *np; np = of_find_matching_node(NULL, sama5d2_pmc_dt_ids);
@@ -144,10 +169,30 @@ 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; + } + + pdev = of_find_device_by_node(np); + of_node_put(np); + if (!pdev) + return -ENODEV; + + 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; } -/* This has to happen before arch_initcall because of the tcb_clksrc driver */ -postcore_initcall(pmc_register_ops); + +subsys_initcall(pmc_register_ops); #endif
--
2.25.1
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