From: Tony Lindgren tony@atomide.com
[ Upstream commit 9d881361206ebcf6285c2ec2ef275aff80875347 ]
Some interconnect target modules such as otg and gpmc on am335x need a re-init after resume. As we also have PM runtime cases where the context may be lost, let's handle these all with cpu_pm.
For the am335x resume path, we already have cpu_pm_resume() call cpu_pm_cluster_exit().
Signed-off-by: Tony Lindgren tony@atomide.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/bus/ti-sysc.c | 108 ++++++++++++++++++++++++-- include/linux/platform_data/ti-sysc.h | 1 + 2 files changed, 103 insertions(+), 6 deletions(-)
diff --git a/drivers/bus/ti-sysc.c b/drivers/bus/ti-sysc.c index 418ada474a85d..51f67223d2514 100644 --- a/drivers/bus/ti-sysc.c +++ b/drivers/bus/ti-sysc.c @@ -6,6 +6,7 @@ #include <linux/io.h> #include <linux/clk.h> #include <linux/clkdev.h> +#include <linux/cpu_pm.h> #include <linux/delay.h> #include <linux/list.h> #include <linux/module.h> @@ -51,11 +52,18 @@ struct sysc_address { struct list_head node; };
+struct sysc_module { + struct sysc *ddata; + struct list_head node; +}; + struct sysc_soc_info { unsigned long general_purpose:1; enum sysc_soc soc; - struct mutex list_lock; /* disabled modules list lock */ + struct mutex list_lock; /* disabled and restored modules list lock */ struct list_head disabled_modules; + struct list_head restored_modules; + struct notifier_block nb; };
enum sysc_clocks { @@ -2402,6 +2410,79 @@ static struct dev_pm_domain sysc_child_pm_domain = { } };
+/* Caller needs to take list_lock if ever used outside of cpu_pm */ +static void sysc_reinit_modules(struct sysc_soc_info *soc) +{ + struct sysc_module *module; + struct list_head *pos; + struct sysc *ddata; + int error = 0; + + list_for_each(pos, &sysc_soc->restored_modules) { + module = list_entry(pos, struct sysc_module, node); + ddata = module->ddata; + error = sysc_reinit_module(ddata, ddata->enabled); + } +} + +/** + * sysc_context_notifier - optionally reset and restore module after idle + * @nb: notifier block + * @cmd: unused + * @v: unused + * + * Some interconnect target modules need to be restored, or reset and restored + * on CPU_PM CPU_PM_CLUSTER_EXIT notifier. This is needed at least for am335x + * OTG and GPMC target modules even if the modules are unused. + */ +static int sysc_context_notifier(struct notifier_block *nb, unsigned long cmd, + void *v) +{ + struct sysc_soc_info *soc; + + soc = container_of(nb, struct sysc_soc_info, nb); + + switch (cmd) { + case CPU_CLUSTER_PM_ENTER: + break; + case CPU_CLUSTER_PM_ENTER_FAILED: /* No need to restore context */ + break; + case CPU_CLUSTER_PM_EXIT: + sysc_reinit_modules(soc); + break; + } + + return NOTIFY_OK; +} + +/** + * sysc_add_restored - optionally add reset and restore quirk hanlling + * @ddata: device data + */ +static void sysc_add_restored(struct sysc *ddata) +{ + struct sysc_module *restored_module; + + restored_module = kzalloc(sizeof(*restored_module), GFP_KERNEL); + if (!restored_module) + return; + + restored_module->ddata = ddata; + + mutex_lock(&sysc_soc->list_lock); + + list_add(&restored_module->node, &sysc_soc->restored_modules); + + if (sysc_soc->nb.notifier_call) + goto out_unlock; + + sysc_soc->nb.notifier_call = sysc_context_notifier; + cpu_pm_register_notifier(&sysc_soc->nb); + +out_unlock: + mutex_unlock(&sysc_soc->list_lock); +} + /** * sysc_legacy_idle_quirk - handle children in omap_device compatible way * @ddata: device driver data @@ -2901,12 +2982,14 @@ static int sysc_add_disabled(unsigned long base) }
/* - * One time init to detect the booted SoC and disable unavailable features. + * One time init to detect the booted SoC, disable unavailable features + * and initialize list for optional cpu_pm notifier. + * * Note that we initialize static data shared across all ti-sysc instances * so ddata is only used for SoC type. This can be called from module_init * once we no longer need to rely on platform data. */ -static int sysc_init_soc(struct sysc *ddata) +static int sysc_init_static_data(struct sysc *ddata) { const struct soc_device_attribute *match; struct ti_sysc_platform_data *pdata; @@ -2922,6 +3005,7 @@ static int sysc_init_soc(struct sysc *ddata)
mutex_init(&sysc_soc->list_lock); INIT_LIST_HEAD(&sysc_soc->disabled_modules); + INIT_LIST_HEAD(&sysc_soc->restored_modules); sysc_soc->general_purpose = true;
pdata = dev_get_platdata(ddata->dev); @@ -2986,15 +3070,24 @@ static int sysc_init_soc(struct sysc *ddata) return 0; }
-static void sysc_cleanup_soc(void) +static void sysc_cleanup_static_data(void) { + struct sysc_module *restored_module; struct sysc_address *disabled_module; struct list_head *pos, *tmp;
if (!sysc_soc) return;
+ if (sysc_soc->nb.notifier_call) + cpu_pm_unregister_notifier(&sysc_soc->nb); + mutex_lock(&sysc_soc->list_lock); + list_for_each_safe(pos, tmp, &sysc_soc->restored_modules) { + restored_module = list_entry(pos, struct sysc_module, node); + list_del(pos); + kfree(restored_module); + } list_for_each_safe(pos, tmp, &sysc_soc->disabled_modules) { disabled_module = list_entry(pos, struct sysc_address, node); list_del(pos); @@ -3062,7 +3155,7 @@ static int sysc_probe(struct platform_device *pdev) ddata->dev = &pdev->dev; platform_set_drvdata(pdev, ddata);
- error = sysc_init_soc(ddata); + error = sysc_init_static_data(ddata); if (error) return error;
@@ -3161,6 +3254,9 @@ static int sysc_probe(struct platform_device *pdev) pm_runtime_put(&pdev->dev); }
+ if (ddata->cfg.quirks & SYSC_QUIRK_REINIT_ON_CTX_LOST) + sysc_add_restored(ddata); + return 0;
err: @@ -3243,7 +3339,7 @@ static void __exit sysc_exit(void) { bus_unregister_notifier(&platform_bus_type, &sysc_nb); platform_driver_unregister(&sysc_driver); - sysc_cleanup_soc(); + sysc_cleanup_static_data(); } module_exit(sysc_exit);
diff --git a/include/linux/platform_data/ti-sysc.h b/include/linux/platform_data/ti-sysc.h index 9837fb011f2fb..989aa30c598dc 100644 --- a/include/linux/platform_data/ti-sysc.h +++ b/include/linux/platform_data/ti-sysc.h @@ -50,6 +50,7 @@ struct sysc_regbits { s8 emufree_shift; };
+#define SYSC_QUIRK_REINIT_ON_CTX_LOST BIT(28) #define SYSC_QUIRK_REINIT_ON_RESUME BIT(27) #define SYSC_QUIRK_GPMC_DEBUG BIT(26) #define SYSC_MODULE_QUIRK_ENA_RESETDONE BIT(25)