[PATCH] MMC: move regulator handling closer to core v4

From: Linus Walleij
Date: Thu Sep 09 2010 - 04:05:34 EST

After discovering a problem in regulator reference counting I
took Mark Brown's advice to move the reference count into the
MMC core by making the regulator status a member of
struct mmc_host.

I took this opportunity to also implement NULL versions of
the regulator functions so as to rid the driver code from
some ugly #ifdef CONFIG_REGULATOR clauses.

Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Liam Girdwood <lrg@xxxxxxxxxxxxxxx>
Cc: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Cc: Tony Lindgren <tony@xxxxxxxxxxx>
Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: Robert Jarzmik <robert.jarzmik@xxxxxxx>
Cc: Sundar Iyer <sundar.iyer@xxxxxxxxxxxxxx>
Cc: Daniel Mack <daniel@xxxxxxxx>
Cc: Pierre Ossman <pierre@xxxxxxxxx>
Cc: Matt Fleming <matt@xxxxxxxxxxxxxxxxx>
Cc: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Cc: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx>
Cc: Eric Miao <eric.y.miao@xxxxxxxxx>
Cc: Cliff Brake <cbrake@xxxxxxxxxxxxxxx>
Cc: Jarkko Lavinen <jarkko.lavinen@xxxxxxxxx>
Cc: linux-mmc@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
Reviewed-by: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxxxxxx>
---
Changes v3->v4:

Propagate errors from regulator_set_ocr() properly in the
pxamci and mmci drivers, as far as is possible until we hit the
fact that mmc_set_ios() returns void and cannot handle error
codes.

Switched a pr_debug() in the PXA driver to a dev_dbg() as well
because it was disturbing to see it.

Andrew, if you want me to go in and fix the mmc_host_struct
.set_ios() member to supply and handle an int return value then I
can make a go, but is it OK to take this patch first and then fix
up that MMC core issue on top of this patch then?
---
drivers/mmc/core/core.c | 26 ++++++++++++++++----------
drivers/mmc/host/mmci.c | 28 ++++++++++++++++++----------
drivers/mmc/host/omap_hsmmc.c | 21 +++++++++++++--------
drivers/mmc/host/pxamci.c | 41 +++++++++++++++++++++++++++++++++--------
include/linux/mmc/host.h | 22 +++++++++++++++++++++-
5 files changed, 101 insertions(+), 37 deletions(-)

diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
index 5db49b1..2d47467 100644
--- a/drivers/mmc/core/core.c
+++ b/drivers/mmc/core/core.c
@@ -771,8 +771,9 @@ EXPORT_SYMBOL(mmc_regulator_get_ocrmask);

/**
* mmc_regulator_set_ocr - set regulator to match host->ios voltage
- * @vdd_bit: zero for power off, else a bit number (host->ios.vdd)
+ * @mmc: the host to regulate
* @supply: regulator to use
+ * @vdd_bit: zero for power off, else a bit number (host->ios.vdd)
*
* Returns zero on success, else negative errno.
*
@@ -780,15 +781,12 @@ EXPORT_SYMBOL(mmc_regulator_get_ocrmask);
* a particular supply voltage. This would normally be called from the
* set_ios() method.
*/
-int mmc_regulator_set_ocr(struct regulator *supply, unsigned short vdd_bit)
+int mmc_regulator_set_ocr(struct mmc_host *mmc,
+ struct regulator *supply,
+ unsigned short vdd_bit)
{
int result = 0;
int min_uV, max_uV;
- int enabled;
-
- enabled = regulator_is_enabled(supply);
- if (enabled < 0)
- return enabled;

if (vdd_bit) {
int tmp;
@@ -819,17 +817,25 @@ int mmc_regulator_set_ocr(struct regulator *supply, unsigned short vdd_bit)
else
result = 0;

- if (result == 0 && !enabled)
+ if (result == 0 && !mmc->regulator_enabled) {
result = regulator_enable(supply);
- } else if (enabled) {
+ if (!result)
+ mmc->regulator_enabled = true;
+ }
+ } else if (mmc->regulator_enabled) {
result = regulator_disable(supply);
+ if (result == 0)
+ mmc->regulator_enabled = false;
}

+ if (result)
+ dev_err(mmc_dev(mmc),
+ "could not set regulator OCR (%d)\n", result);
return result;
}
EXPORT_SYMBOL(mmc_regulator_set_ocr);

-#endif
+#endif /* CONFIG_REGULATOR */

/*
* Mask off any voltages we don't support and select
diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
index 1932e9c..f716e3c 100644
--- a/drivers/mmc/host/mmci.c
+++ b/drivers/mmc/host/mmci.c
@@ -523,19 +523,27 @@ static void mmci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
struct mmci_host *host = mmc_priv(mmc);
u32 pwr = 0;
unsigned long flags;
+ int ret;

switch (ios->power_mode) {
case MMC_POWER_OFF:
- if(host->vcc &&
- regulator_is_enabled(host->vcc))
- regulator_disable(host->vcc);
+ if (host->vcc)
+ ret = mmc_regulator_set_ocr(mmc, host->vcc, 0);
break;
case MMC_POWER_UP:
-#ifdef CONFIG_REGULATOR
- if (host->vcc)
- /* This implicitly enables the regulator */
- mmc_regulator_set_ocr(host->vcc, ios->vdd);
-#endif
+ if (host->vcc) {
+ ret = mmc_regulator_set_ocr(mmc, host->vcc, ios->vdd);
+ if (ret) {
+ dev_err(mmc_dev(mmc), "unable to set OCR\n");
+ /*
+ * The .set_ios() function in the mmc_host_ops
+ * struct return void, and failing to set the
+ * power should be rare so we print an error
+ * and return here.
+ */
+ return;
+ }
+ }
if (host->plat->vdd_handler)
pwr |= host->plat->vdd_handler(mmc_dev(mmc), ios->vdd,
ios->power_mode);
@@ -843,8 +851,8 @@ static int __devexit mmci_remove(struct amba_device *dev)
clk_disable(host->clk);
clk_put(host->clk);

- if (regulator_is_enabled(host->vcc))
- regulator_disable(host->vcc);
+ if (host->vcc)
+ mmc_regulator_set_ocr(mmc, host->vcc, 0);
regulator_put(host->vcc);

mmc_free_host(mmc);
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 4a8776f..14598ca 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -250,9 +250,9 @@ static int omap_hsmmc_1_set_power(struct device *dev, int slot, int power_on,
mmc_slot(host).before_set_reg(dev, slot, power_on, vdd);

if (power_on)
- ret = mmc_regulator_set_ocr(host->vcc, vdd);
+ ret = mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
else
- ret = mmc_regulator_set_ocr(host->vcc, 0);
+ ret = mmc_regulator_set_ocr(host->mmc, host->vcc, 0);

if (mmc_slot(host).after_set_reg)
mmc_slot(host).after_set_reg(dev, slot, power_on, vdd);
@@ -291,18 +291,23 @@ static int omap_hsmmc_23_set_power(struct device *dev, int slot, int power_on,
* chips/cards need an interface voltage rail too.
*/
if (power_on) {
- ret = mmc_regulator_set_ocr(host->vcc, vdd);
+ ret = mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
/* Enable interface voltage rail, if needed */
if (ret == 0 && host->vcc_aux) {
ret = regulator_enable(host->vcc_aux);
if (ret < 0)
- ret = mmc_regulator_set_ocr(host->vcc, 0);
+ ret = mmc_regulator_set_ocr(host->mmc,
+ host->vcc, 0);
}
} else {
+ /* Shut down the rail */
if (host->vcc_aux)
ret = regulator_disable(host->vcc_aux);
- if (ret == 0)
- ret = mmc_regulator_set_ocr(host->vcc, 0);
+ if (!ret) {
+ /* Then proceed to shut down the local regulator */
+ ret = mmc_regulator_set_ocr(host->mmc,
+ host->vcc, 0);
+ }
}

if (mmc_slot(host).after_set_reg)
@@ -343,9 +348,9 @@ static int omap_hsmmc_23_set_sleep(struct device *dev, int slot, int sleep,
if (cardsleep) {
/* VCC can be turned off if card is asleep */
if (sleep)
- err = mmc_regulator_set_ocr(host->vcc, 0);
+ err = mmc_regulator_set_ocr(host->mmc, host->vcc, 0);
else
- err = mmc_regulator_set_ocr(host->vcc, vdd);
+ err = mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
} else
err = regulator_set_mode(host->vcc, mode);
if (err)
diff --git a/drivers/mmc/host/pxamci.c b/drivers/mmc/host/pxamci.c
index 0a4e43f..7609385 100644
--- a/drivers/mmc/host/pxamci.c
+++ b/drivers/mmc/host/pxamci.c
@@ -99,14 +99,25 @@ static inline void pxamci_init_ocr(struct pxamci_host *host)
}
}

-static inline void pxamci_set_power(struct pxamci_host *host, unsigned int vdd)
+static inline int pxamci_set_power(struct pxamci_host *host,
+ unsigned char power_mode,
+ unsigned int vdd)
{
int on;

-#ifdef CONFIG_REGULATOR
- if (host->vcc)
- mmc_regulator_set_ocr(host->vcc, vdd);
-#endif
+ if (host->vcc) {
+ int ret;
+
+ if (power_mode == MMC_POWER_UP) {
+ ret = mmc_regulator_set_ocr(host->mmc, host->vcc, vdd);
+ if (ret)
+ return ret;
+ } else if (power_mode == MMC_POWER_OFF) {
+ ret = mmc_regulator_set_ocr(host->mmc, host->vcc, 0);
+ if (ret)
+ return ret;
+ }
+ }
if (!host->vcc && host->pdata &&
gpio_is_valid(host->pdata->gpio_power)) {
on = ((1 << vdd) & host->pdata->ocr_mask);
@@ -115,6 +126,8 @@ static inline void pxamci_set_power(struct pxamci_host *host, unsigned int vdd)
}
if (!host->vcc && host->pdata && host->pdata->setpower)
host->pdata->setpower(mmc_dev(host->mmc), vdd);
+
+ return 0;
}

static void pxamci_stop_clock(struct pxamci_host *host)
@@ -490,9 +503,21 @@ static void pxamci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
}

if (host->power_mode != ios->power_mode) {
+ int ret;
+
host->power_mode = ios->power_mode;

- pxamci_set_power(host, ios->vdd);
+ ret = pxamci_set_power(host, ios->power_mode, ios->vdd);
+ if (ret) {
+ dev_err(mmc_dev(mmc), "unable to set power\n");
+ /*
+ * The .set_ios() function in the mmc_host_ops
+ * struct return void, and failing to set the
+ * power should be rare so we print an error and
+ * return here.
+ */
+ return;
+ }

if (ios->power_mode == MMC_POWER_ON)
host->cmdat |= CMDAT_INIT;
@@ -503,8 +528,8 @@ static void pxamci_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
else
host->cmdat &= ~CMDAT_SD_4DAT;

- pr_debug("PXAMCI: clkrt = %x cmdat = %x\n",
- host->clkrt, host->cmdat);
+ dev_dbg(mmc_dev(mmc), "PXAMCI: clkrt = %x cmdat = %x\n",
+ host->clkrt, host->cmdat);
}

static void pxamci_enable_sdio_irq(struct mmc_host *host, int enable)
diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
index 1575b52..d009d73 100644
--- a/include/linux/mmc/host.h
+++ b/include/linux/mmc/host.h
@@ -212,6 +212,10 @@ struct mmc_host {
struct led_trigger *led; /* activity led */
#endif

+#ifdef CONFIG_REGULATOR
+ bool regulator_enabled; /* regulator state */
+#endif
+
struct dentry *debugfs_root;

unsigned long private[0] ____cacheline_aligned;
@@ -250,8 +254,24 @@ static inline void mmc_signal_sdio_irq(struct mmc_host *host)

struct regulator;

+#ifdef CONFIG_REGULATOR
int mmc_regulator_get_ocrmask(struct regulator *supply);
-int mmc_regulator_set_ocr(struct regulator *supply, unsigned short vdd_bit);
+int mmc_regulator_set_ocr(struct mmc_host *mmc,
+ struct regulator *supply,
+ unsigned short vdd_bit);
+#else
+int inline mmc_regulator_get_ocrmask(struct regulator *supply)
+{
+ return 0;
+}
+
+int inline mmc_regulator_set_ocr(struct mmc_host *mmc,
+ struct regulator *supply,
+ unsigned short vdd_bit)
+{
+ return 0;
+}
+#endif

int mmc_card_awake(struct mmc_host *host);
int mmc_card_sleep(struct mmc_host *host);
--
1.6.3.3

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