Before going to backup mode architecture specific PM code sets the first word in securam (and it will be cleared in a subsequent commit for the rest of power saving modes). Thus take this into account when suspending/resuming clocks. This will avoid executing unnecessary instructions when suspending to non backup modes. Since the clear of the 1st word in securam will be done in a subsequent commit the current commit will not broke the current behavior since up to this moment the suspend/resume were executed for all AT91 PM modes. The difference now is that the suspend/resume for clocks will be executed for the rest of AT91 PM modes just after the 1st enter/exit to/from backup mode. 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 postcore_initcall().
Signed-off-by: Claudiu Beznea <claudiu.bez...@microchip.com> --- drivers/clk/at91/pmc.c | 48 ++++++++++++++++++++++++++++++++++-------- 1 file changed, 39 insertions(+), 9 deletions(-) diff --git a/drivers/clk/at91/pmc.c b/drivers/clk/at91/pmc.c index 77b57c9f5dcb..c226d33cd899 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(); } @@ -125,24 +149,30 @@ static struct syscore_ops pmc_syscore_ops = { .resume = at91_pmc_resume, }; -static const struct of_device_id sama5d2_pmc_dt_ids[] = { - { .compatible = "atmel,sama5d2-pmc" }, - { /* sentinel */ } -}; - 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); + np = of_find_compatible_node(NULL, NULL, "atmel,sama5d2-securam"); if (!np) - return 0; + 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