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

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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: Tony Lindgren <tony@atomide.com>
This commit is contained in:
Tony Lindgren 2021-09-21 12:42:25 +03:00
parent b3e9431854
commit 95ec14faac
1 changed files with 49 additions and 11 deletions
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60
drivers/bus/ti-sysc.c
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@ -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 @@ set_midle:
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 @@ set_autoidle:
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 @@ set_sidle:
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 @@ set_sidle:
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 @@ err_allow_idle:
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);