From: Adrian Hunter <adrian.hunter@intel.com>
To: Jaehoon Chung <jh80.chung@samsung.com>
Cc: linux-mmc <linux-mmc@vger.kernel.org>,
Chris Ball <cjb@laptop.org>,
Kyungmin Park <kyungmin.park@samsung.com>,
Adrian Hunter <adrian.hunter@intel.com>
Subject: Re: [RFC] mmc: core: add the capability for broken voltage
Date: Tue, 17 Jan 2012 10:00:15 +0200 [thread overview]
Message-ID: <4F152A8F.5070506@intel.com> (raw)
In-Reply-To: <4F13E47D.8040505@samsung.com>
On 16/01/12 10:49, Jaehoon Chung wrote:
> This patch is added the MMC_CAP2_BROKEN_VOLTAGE.
>
> if the voltage didn't satisfy between min_uV and max_uV,
Why is the fixed voltage not in the acceptable range for the card?
Doesn't that risk breaking the card?
> try to change the voltage in core.c.
> When change the voltage, maybe use the regulator_set_voltage().
>
> In regulator_set_voltage(), check the below condition.
>
> /* sanity check */
> if (!rdev->desc->ops->set_voltage &&
> !rdev->desc->ops->set_voltage_sel) {
> ret = -EINVAL;
> goto out;
> }
>
> If Some-board should use the fixed-regulator, always return -EINVAL.
> Then, eMMC didn't initialize always.
>
> So if use the fixed-regulator or etc, we need to add the MMC_CAP2_BROKEN_VOLTAGE.
>
> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
> ---
> drivers/mmc/core/core.c | 4 ++++
> include/linux/mmc/host.h | 1 +
> 2 files changed, 5 insertions(+), 0 deletions(-)
>
> diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c
> index bec0bf2..6848789 100644
> --- a/drivers/mmc/core/core.c
> +++ b/drivers/mmc/core/core.c
> @@ -1121,6 +1121,10 @@ int mmc_regulator_set_ocr(struct mmc_host *mmc,
> * might not allow this operation
> */
> voltage = regulator_get_voltage(supply);
> +
> + if (mmc->caps2 & MMC_CAP2_BROKEN_VOLTAGE)
> + min_uV = max_uV = voltage;
> +
> if (voltage < 0)
> result = voltage;
> else if (voltage < min_uV || voltage > max_uV)
> diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h
> index dd13e05..5659aee 100644
> --- a/include/linux/mmc/host.h
> +++ b/include/linux/mmc/host.h
> @@ -257,6 +257,7 @@ struct mmc_host {
> #define MMC_CAP2_HS200_1_2V_SDR (1 << 6) /* can support */
> #define MMC_CAP2_HS200 (MMC_CAP2_HS200_1_8V_SDR | \
> MMC_CAP2_HS200_1_2V_SDR)
> +#define MMC_CAP2_BROKEN_VOLTAGE (1 << 7) /* Use the broken voltage */
>
> mmc_pm_flag_t pm_caps; /* supported pm features */
> unsigned int power_notify_type;
> --
> To unsubscribe from this list: send the line "unsubscribe linux-mmc" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2012-01-17 8:00 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-16 8:49 [RFC] mmc: core: add the capability for broken voltage Jaehoon Chung
2012-01-17 8:00 ` Adrian Hunter [this message]
2012-01-17 9:05 ` Kyungmin Park
2012-01-17 9:37 ` Adrian Hunter
2012-01-17 9:53 ` Kyungmin Park
2012-01-17 11:47 ` Adrian Hunter
2012-01-17 23:58 ` Kyungmin Park
2012-01-18 8:01 ` Adrian Hunter
2012-01-18 8:13 ` Kyungmin Park
2012-01-18 8:56 ` Adrian Hunter
2012-01-18 13:03 ` Kyungmin Park
2012-01-19 10:14 ` Adrian Hunter
2012-01-19 10:40 ` Kyungmin Park
2012-01-19 14:08 ` Adrian Hunter
2012-02-04 23:24 ` Chris Ball
2012-02-06 10:24 ` Marek Szyprowski
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