On Jun 12, 2012, at 9:52 AM, Guennadi Liakhovetski wrote:
> On Tue, 12 Jun 2012, Philip Rakity wrote:
>
>>
>> On Jun 12, 2012, at 8:57 AM, Guennadi Liakhovetski wrote:
>>
>>> Add a function to get regulators, supplying card's Vdd and Vccq on a
>>> specific host. If a Vdd supplying regulator is found, the function checks,
>>> whether a valid OCR mask can be obtained from it. The Vccq regulator is
>>> optional. A failure to get it is not fatal.
>>>
>>> Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@xxxxxx>
>>> ---
>>>
>>> v4:
>>>
>>> 1. add _GPL to EXPORT_SYMBOL (note: a recently posted patch changes
>>> another occurrence of EXPORT_SYMBOL too, so, this patch will apply with a
>>> fuzz, if merged after)
>>>
>>> 2. add an optional vqmmc regulator, which also changes the function
>>> prototype
>>>
>>> 3. print a warning, if failed to get an OCR mask
>>>
>>> Thanks to all, who commented
>>>
>>> drivers/mmc/core/core.c | 27 +++++++++++++++++++++++++++
>>> include/linux/mmc/host.h | 12 ++++++++++++
>>> 2 files changed, 39 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
>>> index 0b6141d..d77a238 100644
>>> --- a/drivers/mmc/core/core.c
>>> +++ b/drivers/mmc/core/core.c
>>> @@ -1013,6 +1013,33 @@ int mmc_regulator_set_ocr(struct mmc_host *mmc,
>>> }
>>> EXPORT_SYMBOL(mmc_regulator_set_ocr);
>>>
>>> +int mmc_regulator_get_supply(struct mmc_host *mmc, struct mmc_supply *s)
>>> +{
>>> + struct device *dev = mmc_dev(mmc);
>>> + struct regulator *supply;
>>> + int ret;
>>> +
>>> + if (!mmc || !s)
>>> + return -EINVAL;
>>> +
>>> + supply = devm_regulator_get(dev, "vmmc");
>>> +
>>> + if (IS_ERR(supply))
>>> + return PTR_ERR(supply);
>>> +
>>> + s->vmmc = supply;
>>> + s->vqmmc = devm_regulator_get(dev, "vqmmc");
>>
>> Should we set vqmmc to NULL if an error was returned ?
>
> Don't think so, drivers can perfectly check for IS_ERR() themselves.
sdhci.c checks for
if (host->vmmc) {
regulator_disable(host->vmmc);
regulator_put(host->vmmc);
}
so better to set regulator to NULL if not used.
>
>>> +
>>> + ret = mmc_regulator_get_ocrmask(supply);
>>> + if (ret > 0)
>>> + mmc->ocr_avail = ret;
>>> + else
>>> + dev_warn(mmc_dev(mmc), "Failed getting OCR mask: %d\n", ret);
>>
>> I was wondering if sdhci (or the other SD Host drivers can work if no ocr_avail mask is set ?
>
> Yes, e.g., if it's a dummy regulator and the board actually doesn't need
> one.
>
>>> +
>>> + return 0;
>>> +}
>>> +EXPORT_SYMBOL_GPL(mmc_regulator_get_supply);
>>> +
>>> #endif /* CONFIG_REGULATOR */
>>>
>>> /*
>>> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
>>> index 0707d22..3192335 100644
>>> --- a/include/linux/mmc/host.h
>>> +++ b/include/linux/mmc/host.h
>>> @@ -359,11 +359,17 @@ static inline void mmc_signal_sdio_irq(struct mmc_host *host)
>>>
>>> struct regulator;
>>>
>>> +struct mmc_supply {
>>> + struct regulator *vmmc; /* Card power supply */
>>> + struct regulator *vqmmc; /* Optional Vccq supply */
>>> +};
>>> +
>>> #ifdef CONFIG_REGULATOR
>>> int mmc_regulator_get_ocrmask(struct regulator *supply);
>>> int mmc_regulator_set_ocr(struct mmc_host *mmc,
>>> struct regulator *supply,
>>> unsigned short vdd_bit);
>>> +int mmc_regulator_get_supply(struct mmc_host *mmc, struct mmc_supply *s);
>>> #else
>>> static inline int mmc_regulator_get_ocrmask(struct regulator *supply)
>>> {
>>> @@ -376,6 +382,12 @@ static inline int mmc_regulator_set_ocr(struct mmc_host *mmc,
>>> {
>>> return 0;
>>> }
>>> +
>>> +static inline int mmc_regulator_get_supply(struct mmc_host *mmc,
>>> + struct mmc_supply *s)
>>> +{
>>> + return 0;
>>> +}
>>> #endif
>>>
>>> int mmc_card_awake(struct mmc_host *host);
>>> --
>>> 1.7.2.5
>
> Thanks
> Guennadi
> ---
> Guennadi Liakhovetski, Ph.D.
> Freelance Open-Source Software Developer
> http://www.open-technology.de/
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