* [PATCH 2/2] mmc: core: fix the signaling 1.8V for HS200
@ 2012-04-23 9:11 Seungwon Jeon
2012-04-24 8:12 ` Subhash Jadavani
0 siblings, 1 reply; 4+ messages in thread
From: Seungwon Jeon @ 2012-04-23 9:11 UTC (permalink / raw)
To: linux-mmc; +Cc: 'Chris Ball', 'Girish K S'
Currently only 1.2V is treated for HS200 mode. If the host has
only 1.8V I/O capability not 1.2V, mmc_set_signal_voltage can't
be called for 1.8V HS200. EXT_CSD_CARD_TYPE_SDR_1_8V needs to be
considered.
Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
---
drivers/mmc/core/mmc.c | 12 +++++++-----
1 files changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
index ebb9522..71eb320 100644
--- a/drivers/mmc/core/mmc.c
+++ b/drivers/mmc/core/mmc.c
@@ -732,7 +732,7 @@ static int mmc_select_powerclass(struct mmc_card *card,
*/
static int mmc_select_hs200(struct mmc_card *card)
{
- int idx, err = 0;
+ int idx, err = -EINVAL;
struct mmc_host *host;
static unsigned ext_csd_bits[] = {
EXT_CSD_BUS_WIDTH_4,
@@ -748,10 +748,12 @@ static int mmc_select_hs200(struct mmc_card *card)
host = card->host;
if (card->ext_csd.card_type & EXT_CSD_CARD_TYPE_SDR_1_2V &&
- host->caps2 & MMC_CAP2_HS200_1_2V_SDR)
- if (mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120, 0))
- err = mmc_set_signal_voltage(host,
- MMC_SIGNAL_VOLTAGE_180, 0);
+ host->caps2 & MMC_CAP2_HS200_1_2V_SDR)
+ err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120, 0);
+
+ if (err && card->ext_csd.card_type & EXT_CSD_CARD_TYPE_SDR_1_8V &&
+ host->caps2 & MMC_CAP2_HS200_1_8V_SDR)
+ err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180, 0);
/* If fails try again during next card power cycle */
if (err)
--
1.7.0.4
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 2/2] mmc: core: fix the signaling 1.8V for HS200
2012-04-23 9:11 [PATCH 2/2] mmc: core: fix the signaling 1.8V for HS200 Seungwon Jeon
@ 2012-04-24 8:12 ` Subhash Jadavani
2012-04-25 5:15 ` Seungwon Jeon
0 siblings, 1 reply; 4+ messages in thread
From: Subhash Jadavani @ 2012-04-24 8:12 UTC (permalink / raw)
To: Seungwon Jeon; +Cc: linux-mmc, 'Chris Ball', 'Girish K S'
Hi Seungwon,
On 4/23/2012 2:41 PM, Seungwon Jeon wrote:
> Currently only 1.2V is treated for HS200 mode. If the host has
> only 1.8V I/O capability not 1.2V, mmc_set_signal_voltage can't
> be called for 1.8V HS200. EXT_CSD_CARD_TYPE_SDR_1_8V needs to be
> considered.
Commit text looks confusing to me. In this change, you are trying to set
the 1.8V I/O voltage only if there is an error setting the 1.2v I/O? Can
you please clarify more?
>
> Signed-off-by: Seungwon Jeon<tgih.jun@samsung.com>
> ---
> drivers/mmc/core/mmc.c | 12 +++++++-----
> 1 files changed, 7 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> index ebb9522..71eb320 100644
> --- a/drivers/mmc/core/mmc.c
> +++ b/drivers/mmc/core/mmc.c
> @@ -732,7 +732,7 @@ static int mmc_select_powerclass(struct mmc_card *card,
> */
> static int mmc_select_hs200(struct mmc_card *card)
> {
> - int idx, err = 0;
> + int idx, err = -EINVAL;
> struct mmc_host *host;
> static unsigned ext_csd_bits[] = {
> EXT_CSD_BUS_WIDTH_4,
> @@ -748,10 +748,12 @@ static int mmc_select_hs200(struct mmc_card *card)
> host = card->host;
>
> if (card->ext_csd.card_type& EXT_CSD_CARD_TYPE_SDR_1_2V&&
> - host->caps2& MMC_CAP2_HS200_1_2V_SDR)
> - if (mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120, 0))
> - err = mmc_set_signal_voltage(host,
> - MMC_SIGNAL_VOLTAGE_180, 0);
> + host->caps2& MMC_CAP2_HS200_1_2V_SDR)
> + err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120, 0);
> +
> + if (err&& card->ext_csd.card_type& EXT_CSD_CARD_TYPE_SDR_1_8V&&
> + host->caps2& MMC_CAP2_HS200_1_8V_SDR)
> + err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180, 0);
>
> /* If fails try again during next card power cycle */
> if (err)
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH 2/2] mmc: core: fix the signaling 1.8V for HS200
2012-04-24 8:12 ` Subhash Jadavani
@ 2012-04-25 5:15 ` Seungwon Jeon
2012-04-25 6:24 ` Subhash Jadavani
0 siblings, 1 reply; 4+ messages in thread
From: Seungwon Jeon @ 2012-04-25 5:15 UTC (permalink / raw)
To: 'Subhash Jadavani'
Cc: linux-mmc, 'Chris Ball', 'Girish K S'
Subhash Jadavani <subhashj@codeaurora.org> wrote:
> Hi Seungwon,
>
> On 4/23/2012 2:41 PM, Seungwon Jeon wrote:
> > Currently only 1.2V is treated for HS200 mode. If the host has
> > only 1.8V I/O capability not 1.2V, mmc_set_signal_voltage can't
> > be called for 1.8V HS200. EXT_CSD_CARD_TYPE_SDR_1_8V needs to be
> > considered.
> Commit text looks confusing to me. In this change, you are trying to set
> the 1.8V I/O voltage only if there is an error setting the 1.2v I/O? Can
> you please clarify more?
This patch's purpose is to support 1.8V I/O. Origin considers only 1.2V I/O case.
If the host has only 1.8V capability and card type is HS200 1.8V, there is no way to 1.8V I/O.
Assuming that card is type of HS200 1.2V and host has 1.2V capability,
the 1.2 I/O voltage will be tried. If it succeeds in 1.2V I/O ,
we don't need to trying the 1.8V I/O voltage though 1.8V I/O is possible.
But the 1.8V I/O may be tried in case of 1.2V I/O failure, so error condition is needed.
And error is initialized by -EINVAL at the first time.
Thus, if card and host only are capable of 1.8V I/O, we can try to set the 1.8V I/O
regardless of 1.2V I/O result.
Best regards,
Seungwon Jeon.
> >
> > Signed-off-by: Seungwon Jeon<tgih.jun@samsung.com>
> > ---
> > drivers/mmc/core/mmc.c | 12 +++++++-----
> > 1 files changed, 7 insertions(+), 5 deletions(-)
> >
> > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
> > index ebb9522..71eb320 100644
> > --- a/drivers/mmc/core/mmc.c
> > +++ b/drivers/mmc/core/mmc.c
> > @@ -732,7 +732,7 @@ static int mmc_select_powerclass(struct mmc_card *card,
> > */
> > static int mmc_select_hs200(struct mmc_card *card)
> > {
> > - int idx, err = 0;
> > + int idx, err = -EINVAL;
> > struct mmc_host *host;
> > static unsigned ext_csd_bits[] = {
> > EXT_CSD_BUS_WIDTH_4,
> > @@ -748,10 +748,12 @@ static int mmc_select_hs200(struct mmc_card *card)
> > host = card->host;
> >
> > if (card->ext_csd.card_type& EXT_CSD_CARD_TYPE_SDR_1_2V&&
> > - host->caps2& MMC_CAP2_HS200_1_2V_SDR)
> > - if (mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120, 0))
> > - err = mmc_set_signal_voltage(host,
> > - MMC_SIGNAL_VOLTAGE_180, 0);
> > + host->caps2& MMC_CAP2_HS200_1_2V_SDR)
> > + err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_120, 0);
> > +
> > + if (err&& card->ext_csd.card_type& EXT_CSD_CARD_TYPE_SDR_1_8V&&
> > + host->caps2& MMC_CAP2_HS200_1_8V_SDR)
> > + err = mmc_set_signal_voltage(host, MMC_SIGNAL_VOLTAGE_180, 0);
> >
> > /* If fails try again during next card power cycle */
> > if (err)
>
> --
> 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
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH 2/2] mmc: core: fix the signaling 1.8V for HS200
2012-04-25 5:15 ` Seungwon Jeon
@ 2012-04-25 6:24 ` Subhash Jadavani
0 siblings, 0 replies; 4+ messages in thread
From: Subhash Jadavani @ 2012-04-25 6:24 UTC (permalink / raw)
To: 'Seungwon Jeon'
Cc: linux-mmc, 'Chris Ball', 'Girish K S'
> -----Original Message-----
> From: Seungwon Jeon [mailto:tgih.jun@samsung.com]
> Sent: Wednesday, April 25, 2012 10:46 AM
> To: 'Subhash Jadavani'
> Cc: linux-mmc@vger.kernel.org; 'Chris Ball'; 'Girish K S'
> Subject: RE: [PATCH 2/2] mmc: core: fix the signaling 1.8V for HS200
>
> Subhash Jadavani <subhashj@codeaurora.org> wrote:
> > Hi Seungwon,
> >
> > On 4/23/2012 2:41 PM, Seungwon Jeon wrote:
> > > Currently only 1.2V is treated for HS200 mode. If the host has only
> > > 1.8V I/O capability not 1.2V, mmc_set_signal_voltage can't be called
> > > for 1.8V HS200. EXT_CSD_CARD_TYPE_SDR_1_8V needs to be considered.
> > Commit text looks confusing to me. In this change, you are trying to
> > set the 1.8V I/O voltage only if there is an error setting the 1.2v
> > I/O? Can you please clarify more?
> This patch's purpose is to support 1.8V I/O. Origin considers only 1.2V I/O case.
> If the host has only 1.8V capability and card type is HS200 1.8V, there is no way
> to 1.8V I/O.
Thanks for clarification. I was assuming that most of the devices will have I/O voltage always set to 1.8v by host (when device is powered up) but yes, according to spec, it's possible that I/O may be at 3.3v (high voltage) as well.
This patch looks good to me.
Reviewed-by: Subhash Jadavani <subhashj@codeaurora.org>
Regards,
Subhash
>
> Assuming that card is type of HS200 1.2V and host has 1.2V capability, the 1.2
> I/O voltage will be tried. If it succeeds in 1.2V I/O , we don't need to trying the
> 1.8V I/O voltage though 1.8V I/O is possible.
> But the 1.8V I/O may be tried in case of 1.2V I/O failure, so error condition is
> needed.
>
> And error is initialized by -EINVAL at the first time.
> Thus, if card and host only are capable of 1.8V I/O, we can try to set the 1.8V
> I/O regardless of 1.2V I/O result.
>
> Best regards,
> Seungwon Jeon.
>
> > >
> > > Signed-off-by: Seungwon Jeon<tgih.jun@samsung.com>
> > > ---
> > > drivers/mmc/core/mmc.c | 12 +++++++-----
> > > 1 files changed, 7 insertions(+), 5 deletions(-)
> > >
> > > diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c index
> > > ebb9522..71eb320 100644
> > > --- a/drivers/mmc/core/mmc.c
> > > +++ b/drivers/mmc/core/mmc.c
> > > @@ -732,7 +732,7 @@ static int mmc_select_powerclass(struct mmc_card
> *card,
> > > */
> > > static int mmc_select_hs200(struct mmc_card *card)
> > > {
> > > - int idx, err = 0;
> > > + int idx, err = -EINVAL;
> > > struct mmc_host *host;
> > > static unsigned ext_csd_bits[] = {
> > > EXT_CSD_BUS_WIDTH_4,
> > > @@ -748,10 +748,12 @@ static int mmc_select_hs200(struct mmc_card
> *card)
> > > host = card->host;
> > >
> > > if (card->ext_csd.card_type& EXT_CSD_CARD_TYPE_SDR_1_2V&&
> > > - host->caps2& MMC_CAP2_HS200_1_2V_SDR)
> > > - if (mmc_set_signal_voltage(host,
> MMC_SIGNAL_VOLTAGE_120, 0))
> > > - err = mmc_set_signal_voltage(host,
> > > -
> MMC_SIGNAL_VOLTAGE_180, 0);
> > > + host->caps2& MMC_CAP2_HS200_1_2V_SDR)
> > > + err = mmc_set_signal_voltage(host,
> MMC_SIGNAL_VOLTAGE_120, 0);
> > > +
> > > + if (err&& card->ext_csd.card_type&
> EXT_CSD_CARD_TYPE_SDR_1_8V&&
> > > + host->caps2& MMC_CAP2_HS200_1_8V_SDR)
> > > + err = mmc_set_signal_voltage(host,
> MMC_SIGNAL_VOLTAGE_180, 0);
> > >
> > > /* If fails try again during next card power cycle */
> > > if (err)
> >
> > --
> > 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
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-04-25 6:24 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2012-04-23 9:11 [PATCH 2/2] mmc: core: fix the signaling 1.8V for HS200 Seungwon Jeon
2012-04-24 8:12 ` Subhash Jadavani
2012-04-25 5:15 ` Seungwon Jeon
2012-04-25 6:24 ` Subhash Jadavani
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