Commit 9d881361 authored by Tony Lindgren's avatar Tony Lindgren
Browse files

bus: ti-sysc: Add quirk handling for reinit on context lost 



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: default avatarTony Lindgren <tony@atomide.com>
parent 95ec14fa

drivers/bus/ti-sysc.c

+102 −6
Original line number Diff line number Diff line
@@ -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>
@@ -52,11 +53,18 @@ 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 {
@@ -2477,6 +2485,79 @@ 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
@@ -2976,12 +3057,14 @@ 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;
@@ -2997,6 +3080,7 @@ 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);
@@ -3060,15 +3144,24 @@ 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);
@@ -3136,7 +3229,7 @@ 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;
@@ -3234,6 +3327,9 @@ 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:
@@ -3315,7 +3411,7 @@ 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);

include/linux/platform_data/ti-sysc.h

+1 −0
Original line number Diff line number Diff line
@@ -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)