From: Adrian Hunter <adrian.hunter@xxxxxxxxx>
When a card is not in use, the voltage regulator can be put to sleep.
This is an alternative to powering the card off, when powering off is not
safe because the card might be replaced without the driver being aware of
it.
That situation happens if:
- the card is removable i.e. not eMMC
- and there is no card detect
- and there is a cover switch but the cover is open
Signed-off-by: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Acked-by: Matt Fleming <matt@xxxxxxxxxxxxxxxxx>
Cc: Ian Molton <ian@xxxxxxxxxxxxxx>
Cc: "Roberto A. Foglietta" <roberto.foglietta@xxxxxxxxx>
Cc: Jarkko Lavinen <jarkko.lavinen@xxxxxxxxx>
Cc: Denis Karpov <ext-denis.2.karpov@xxxxxxxxx>
Cc: Pierre Ossman <pierre@xxxxxxxxx>
Cc: Philip Langdale <philipl@xxxxxxxxx>
Cc: "Madhusudhan" <madhu.cr@xxxxxx>
Cc: <linux-mmc@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/mmc/host/omap_hsmmc.c | 59 +++++++++++++++++++++++++++++---
1 file changed, 54 insertions(+), 5 deletions(-)
diff -puN drivers/mmc/host/omap_hsmmc.c~omap_hsmmc-put-mmc-regulator-to-sleep drivers/mmc/host/omap_hsmmc.c
--- a/drivers/mmc/host/omap_hsmmc.c~omap_hsmmc-put-mmc-regulator-to-sleep
+++ a/drivers/mmc/host/omap_hsmmc.c
@@ -162,6 +162,7 @@ struct mmc_omap_host {
int response_busy;
int context_loss;
int dpm_state;
+ int vdd;
struct omap_mmc_platform_data *pdata;
};
@@ -1038,10 +1039,12 @@ static void omap_mmc_set_ios(struct mmc_
case MMC_POWER_OFF:
mmc_slot(host).set_power(host->dev, host->slot_id,
0, 0);
+ host->vdd = 0;
break;
case MMC_POWER_UP:
mmc_slot(host).set_power(host->dev, host->slot_id,
1, ios->vdd);
+ host->vdd = ios->vdd;
break;
case MMC_POWER_ON:
do_send_init_stream = 1;
@@ -1179,19 +1182,20 @@ static void omap_hsmmc_init(struct mmc_o
/*
* Dynamic power saving handling, FSM:
- * ENABLED -> DISABLED -> OFF
+ * ENABLED -> DISABLED -> OFF / REGSLEEP
* ^___________| |
* |______________________|
*
* ENABLED: mmc host is fully functional
* DISABLED: fclk is off
* OFF: fclk is off,voltage regulator is off
+ * REGSLEEP: fclk is off,voltage regulator is asleep
*
* Transition handlers return the timeout for the next state transition
* or negative error.
*/
-enum {ENABLED = 0, DISABLED, OFF};
+enum {ENABLED = 0, DISABLED, REGSLEEP, OFF};
/* Handler for [ENABLED -> DISABLED] transition */
static int omap_mmc_enabled_to_disabled(struct mmc_omap_host *host)
@@ -1228,8 +1232,12 @@ static int omap_mmc_disabled_to_off(stru
mmc_slot(host).get_cover_state(host->dev, host->slot_id))) {
mmc_power_save_host(host->mmc);
new_state = OFF;
- } else
- new_state = DISABLED;
+ } else {
+ if (mmc_slot(host).set_sleep)
+ mmc_slot(host).set_sleep(host->dev, host->slot_id,
+ 1, 0, 0);
+ new_state = REGSLEEP;
+ }
OMAP_HSMMC_WRITE(host->base, ISE, 0);
OMAP_HSMMC_WRITE(host->base, IE, 0);
@@ -1286,6 +1294,44 @@ static int omap_mmc_off_to_enabled(struc
return 0;
}
+/* Handler for [REGSLEEP -> ENABLED] transition */
+static int omap_mmc_regsleep_to_enabled(struct mmc_omap_host *host)
+{
+ unsigned long timeout;
+
+ dev_dbg(mmc_dev(host->mmc), "REGSLEEP -> ENABLED\n");
+
+ clk_enable(host->fclk);
+ clk_enable(host->iclk);
+
+ if (clk_enable(host->dbclk))
+ dev_dbg(mmc_dev(host->mmc),
+ "Enabling debounce clk failed\n");
+
+ omap_mmc_restore_ctx(host);
+
+ /*
+ * We turned off interrupts and bus power. Interrupts
+ * are turned on by 'mmc_omap_start_command()' so we
+ * just need to turn on the bus power here.
+ */
+ OMAP_HSMMC_WRITE(host->base, HCTL,
+ OMAP_HSMMC_READ(host->base, HCTL) | SDBP);
+
+ timeout = jiffies + msecs_to_jiffies(MMC_TIMEOUT_MS);
+ while ((OMAP_HSMMC_READ(host->base, HCTL) & SDBP) != SDBP &&
+ time_before(jiffies, timeout))
+ ;
+
+ if (mmc_slot(host).set_sleep)
+ mmc_slot(host).set_sleep(host->dev, host->slot_id,
+ 0, host->vdd, 0);
+
+ host->dpm_state = ENABLED;
+
+ return 0;
+}
+
/*
* Bring MMC host to ENABLED from any other PM state.
*/
@@ -1296,6 +1342,8 @@ static int omap_mmc_enable(struct mmc_ho
switch (host->dpm_state) {
case DISABLED:
return omap_mmc_disabled_to_enabled(host);
+ case REGSLEEP:
+ return omap_mmc_regsleep_to_enabled(host);
case OFF:
return omap_mmc_off_to_enabled(host);
default:
@@ -1393,7 +1441,8 @@ static int mmc_regs_show(struct seq_file
host->dpm_state, mmc->nesting_cnt,
host->context_loss, context_loss);
- if (host->suspended || host->dpm_state == OFF) {
+ if (host->suspended || host->dpm_state == OFF ||
+ host->dpm_state == REGSLEEP) {
seq_printf(s, "host suspended, can't read registers\n");
return 0;
}
_
--
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