Commit 95ec14fa authored by Tony Lindgren's avatar Tony Lindgren
Browse files

bus: ti-sysc: Check for lost context in sysc_reinit_module() 



There is no need to restore context if it was not lost. Let's add a new
function sysc_check_context() to check for lost context. To make use of it,
we need to save the sysconfig register status on enable and disable.

Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
parent b3e94318

drivers/bus/ti-sysc.c

+49 −11
Original line number Diff line number Diff line
@@ -132,6 +132,7 @@ struct sysc { 
	struct ti_sysc_cookie cookie;

	const char *name;

	u32 revision;

	u32 sysconfig;

	unsigned int reserved:1;

	unsigned int enabled:1;

	unsigned int needs_resume:1;
@@ -1135,7 +1136,8 @@ static int sysc_enable_module(struct device *dev) 
	best_mode = fls(ddata->cfg.midlemodes) - 1;

	if (best_mode > SYSC_IDLE_MASK) {

		dev_err(dev, "%s: invalid midlemode\n", __func__);

		return -EINVAL;

		error = -EINVAL;

		goto save_context;

	}



	if (ddata->cfg.quirks & SYSC_QUIRK_SWSUP_MSTANDBY)
@@ -1153,13 +1155,16 @@ static int sysc_enable_module(struct device *dev) 
		sysc_write_sysconfig(ddata, reg);

	}



	/* Flush posted write */

	sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]);

	error = 0;



save_context:

	/* Save context and flush posted write */

	ddata->sysconfig = sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]);



	if (ddata->module_enable_quirk)

		ddata->module_enable_quirk(ddata);



	return 0;

	return error;

}



static int sysc_best_idle_mode(u32 idlemodes, u32 *best_mode)
@@ -1216,8 +1221,10 @@ static int sysc_disable_module(struct device *dev) 
set_sidle:

	/* Set SIDLE mode */

	idlemodes = ddata->cfg.sidlemodes;

	if (!idlemodes || regbits->sidle_shift < 0)

		return 0;

	if (!idlemodes || regbits->sidle_shift < 0) {

		ret = 0;

		goto save_context;

	}



	if (ddata->cfg.quirks & SYSC_QUIRK_SWSUP_SIDLE) {

		best_mode = SYSC_IDLE_FORCE;
@@ -1225,7 +1232,8 @@ static int sysc_disable_module(struct device *dev) 
		ret = sysc_best_idle_mode(idlemodes, &best_mode);

		if (ret) {

			dev_err(dev, "%s: invalid sidlemode\n", __func__);

			return ret;

			ret = -EINVAL;

			goto save_context;

		}

	}
@@ -1236,10 +1244,13 @@ static int sysc_disable_module(struct device *dev) 
		reg |= 1 << regbits->autoidle_shift;

	sysc_write_sysconfig(ddata, reg);



	/* Flush posted write */

	sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]);

	ret = 0;



	return 0;

save_context:

	/* Save context and flush posted write */

	ddata->sysconfig = sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]);



	return ret;

}



static int __maybe_unused sysc_runtime_suspend_legacy(struct device *dev,
@@ -1377,13 +1388,40 @@ static int __maybe_unused sysc_runtime_resume(struct device *dev) 
	return error;

}



/*

 * Checks if device context was lost. Assumes the sysconfig register value

 * after lost context is different from the configured value. Only works for

 * enabled devices.

 *

 * Eventually we may want to also add support to using the context lost

 * registers that some SoCs have.

 */

static int sysc_check_context(struct sysc *ddata)

{

	u32 reg;



	if (!ddata->enabled)

		return -ENODATA;



	reg = sysc_read(ddata, ddata->offsets[SYSC_SYSCONFIG]);

	if (reg == ddata->sysconfig)

		return 0;



	return -EACCES;

}



static int sysc_reinit_module(struct sysc *ddata, bool leave_enabled)

{

	struct device *dev = ddata->dev;

	int error;



	/* Disable target module if it is enabled */

	if (ddata->enabled) {

		/* Nothing to do if enabled and context not lost */

		error = sysc_check_context(ddata);

		if (!error)

			return 0;



		/* Disable target module if it is enabled */

		error = sysc_runtime_suspend(dev);

		if (error)

			dev_warn(dev, "reinit suspend failed: %i\n", error);