diff mbox series

[V12,10/23] mmc: sdhci-uhs2: add reset function and uhs2_mode function

Message ID 20230915094351.11120-11-victorshihgli@gmail.com
State New
Headers
Series Add support UHS-II for GL9755 |

Commit Message

Victor Shih Sept. 15, 2023, 9:43 a.m. UTC 
  From: Victor Shih <victor.shih@genesyslogic.com.tw>

Sdhci_uhs2_reset() does a UHS-II specific reset operation.

Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
---

Updates in V8:
 - Adjust the position of matching brackets.

Updates in V6:
 - Remove unnecessary functions and simplify code.

---

 drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
 drivers/mmc/host/sdhci-uhs2.h |  2 ++
 2 files changed, 47 insertions(+)

Comments

Ulf Hansson Oct. 3, 2023, 10:30 a.m. UTC | #1 
On Fri, 15 Sept 2023 at 11:44, Victor Shih <victorshihgli@gmail.com> wrote:
>
> From: Victor Shih <victor.shih@genesyslogic.com.tw>
>
> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
>
> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
> ---
>
> Updates in V8:
>  - Adjust the position of matching brackets.
>
> Updates in V6:
>  - Remove unnecessary functions and simplify code.
>
> ---
>
>  drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
>  drivers/mmc/host/sdhci-uhs2.h |  2 ++
>  2 files changed, 47 insertions(+)
>
> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> index e339821d3504..dfc80a7f1bad 100644
> --- a/drivers/mmc/host/sdhci-uhs2.c
> +++ b/drivers/mmc/host/sdhci-uhs2.c
> @@ -10,7 +10,9 @@
>   *  Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
>   */
>
> +#include <linux/delay.h>
>  #include <linux/module.h>
> +#include <linux/iopoll.h>
>
>  #include "sdhci.h"
>  #include "sdhci-uhs2.h"
> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
>  }
>  EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
>
> +/*****************************************************************************\
> + *                                                                           *
> + * Low level functions                                                       *
> + *                                                                           *
> +\*****************************************************************************/
> +
> +bool sdhci_uhs2_mode(struct sdhci_host *host)
> +{
> +       return host->mmc->flags & MMC_UHS2_SUPPORT;

The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
should be using mmc->ios.timings, which already indicates whether we
are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
this.

That said, I think we should drop the sdhci_uhs2_mode() function
altogether and instead use mmc_card_uhs2(), which means we should move
it to include/linux/mmc/host.h, so it becomes available for host
drivers.

> +}
> +
> +/**
> + * sdhci_uhs2_reset - invoke SW reset
> + * @host: SDHCI host
> + * @mask: Control mask
> + *
> + * Invoke SW reset, depending on a bit in @mask and wait for completion.
> + */
> +void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask)
> +{
> +       unsigned long timeout;
> +       u32 val;
> +
> +       sdhci_writew(host, mask, SDHCI_UHS2_SW_RESET);
> +
> +       if (mask & SDHCI_UHS2_SW_RESET_FULL)
> +               host->clock = 0;
> +
> +       /* Wait max 100 ms */
> +       timeout = 100000;

Please convert into using a define and use that directly, below instead.

> +
> +       /* hw clears the bit when it's done */
> +       if (read_poll_timeout_atomic(sdhci_readw, val, !(val & mask), 10,
> +                                    timeout, true, host, SDHCI_UHS2_SW_RESET)) {
> +               pr_err("%s: %s: Reset 0x%x never completed.\n", __func__,
> +                      mmc_hostname(host->mmc), (int)mask);
> +               pr_err("%s: clean reset bit\n", mmc_hostname(host->mmc));

It looks silly to do two pr_err immediately after each other, please
combine them into one.

Moreover, I think we should probably convert into using a pr_warn() instead.

> +               sdhci_writeb(host, 0, SDHCI_UHS2_SW_RESET);
> +               return;
> +       }
> +}
> +EXPORT_SYMBOL_GPL(sdhci_uhs2_reset);
> +
>  /*****************************************************************************\
>   *                                                                           *
>   * Driver init/exit                                                          *
> diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
> index 2bfe18d29bca..8253d50f7852 100644
> --- a/drivers/mmc/host/sdhci-uhs2.h
> +++ b/drivers/mmc/host/sdhci-uhs2.h
> @@ -177,5 +177,7 @@
>  struct sdhci_host;
>
>  void sdhci_uhs2_dump_regs(struct sdhci_host *host);
> +bool sdhci_uhs2_mode(struct sdhci_host *host);
> +void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask);
>
>  #endif /* __SDHCI_UHS2_H */
> --
> 2.25.1
>

Kind regards
Uffe
Adrian Hunter Oct. 3, 2023, 11:37 a.m. UTC | #2 
On 3/10/23 13:30, Ulf Hansson wrote:
> On Fri, 15 Sept 2023 at 11:44, Victor Shih <victorshihgli@gmail.com> wrote:
>>
>> From: Victor Shih <victor.shih@genesyslogic.com.tw>
>>
>> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
>>
>> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
>> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
>> Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
>> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
>> ---
>>
>> Updates in V8:
>>  - Adjust the position of matching brackets.
>>
>> Updates in V6:
>>  - Remove unnecessary functions and simplify code.
>>
>> ---
>>
>>  drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
>>  drivers/mmc/host/sdhci-uhs2.h |  2 ++
>>  2 files changed, 47 insertions(+)
>>
>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
>> index e339821d3504..dfc80a7f1bad 100644
>> --- a/drivers/mmc/host/sdhci-uhs2.c
>> +++ b/drivers/mmc/host/sdhci-uhs2.c
>> @@ -10,7 +10,9 @@
>>   *  Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
>>   */
>>
>> +#include <linux/delay.h>
>>  #include <linux/module.h>
>> +#include <linux/iopoll.h>
>>
>>  #include "sdhci.h"
>>  #include "sdhci-uhs2.h"
>> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
>>  }
>>  EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
>>
>> +/*****************************************************************************\
>> + *                                                                           *
>> + * Low level functions                                                       *
>> + *                                                                           *
>> +\*****************************************************************************/
>> +
>> +bool sdhci_uhs2_mode(struct sdhci_host *host)
>> +{
>> +       return host->mmc->flags & MMC_UHS2_SUPPORT;
> 
> The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
> should be using mmc->ios.timings, which already indicates whether we
> are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
> this.
> 
> That said, I think we should drop the sdhci_uhs2_mode() function
> altogether and instead use mmc_card_uhs2(), which means we should move
> it to include/linux/mmc/host.h, so it becomes available for host
> drivers.
> 

UHS2 mode starts at UHS2 initialization and ends either when UHS2
initialization fails, or the card is removed.

So it includes re-initialization and reset when the transfer mode
currently transitions through MMC_TIMING_LEGACY.

So mmc_card_uhs2() won't work correctly for the host callbacks
unless something is done about that.
Ulf Hansson Oct. 3, 2023, 12:22 p.m. UTC | #3 
On Tue, 3 Oct 2023 at 13:37, Adrian Hunter <adrian.hunter@intel.com> wrote:
>
> On 3/10/23 13:30, Ulf Hansson wrote:
> > On Fri, 15 Sept 2023 at 11:44, Victor Shih <victorshihgli@gmail.com> wrote:
> >>
> >> From: Victor Shih <victor.shih@genesyslogic.com.tw>
> >>
> >> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
> >>
> >> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> >> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> >> Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
> >> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
> >> ---
> >>
> >> Updates in V8:
> >>  - Adjust the position of matching brackets.
> >>
> >> Updates in V6:
> >>  - Remove unnecessary functions and simplify code.
> >>
> >> ---
> >>
> >>  drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
> >>  drivers/mmc/host/sdhci-uhs2.h |  2 ++
> >>  2 files changed, 47 insertions(+)
> >>
> >> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> >> index e339821d3504..dfc80a7f1bad 100644
> >> --- a/drivers/mmc/host/sdhci-uhs2.c
> >> +++ b/drivers/mmc/host/sdhci-uhs2.c
> >> @@ -10,7 +10,9 @@
> >>   *  Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
> >>   */
> >>
> >> +#include <linux/delay.h>
> >>  #include <linux/module.h>
> >> +#include <linux/iopoll.h>
> >>
> >>  #include "sdhci.h"
> >>  #include "sdhci-uhs2.h"
> >> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> >>  }
> >>  EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
> >>
> >> +/*****************************************************************************\
> >> + *                                                                           *
> >> + * Low level functions                                                       *
> >> + *                                                                           *
> >> +\*****************************************************************************/
> >> +
> >> +bool sdhci_uhs2_mode(struct sdhci_host *host)
> >> +{
> >> +       return host->mmc->flags & MMC_UHS2_SUPPORT;
> >
> > The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
> > should be using mmc->ios.timings, which already indicates whether we
> > are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
> > this.
> >
> > That said, I think we should drop the sdhci_uhs2_mode() function
> > altogether and instead use mmc_card_uhs2(), which means we should move
> > it to include/linux/mmc/host.h, so it becomes available for host
> > drivers.
> >
>
> UHS2 mode starts at UHS2 initialization and ends either when UHS2
> initialization fails, or the card is removed.
>
> So it includes re-initialization and reset when the transfer mode
> currently transitions through MMC_TIMING_LEGACY.
>
> So mmc_card_uhs2() won't work correctly for the host callbacks
> unless something is done about that.

Right, thanks for clarifying!

In that case I wonder if we couldn't change the way we update the
->ios.timing for UHS2. It seems silly to have two (similar) ways to
indicate that we have moved to UHS2.

Kind regards
Uffe
Adrian Hunter Oct. 3, 2023, 3:02 p.m. UTC | #4 
On 3/10/23 15:22, Ulf Hansson wrote:
> On Tue, 3 Oct 2023 at 13:37, Adrian Hunter <adrian.hunter@intel.com> wrote:
>>
>> On 3/10/23 13:30, Ulf Hansson wrote:
>>> On Fri, 15 Sept 2023 at 11:44, Victor Shih <victorshihgli@gmail.com> wrote:
>>>>
>>>> From: Victor Shih <victor.shih@genesyslogic.com.tw>
>>>>
>>>> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
>>>>
>>>> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
>>>> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
>>>> Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
>>>> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
>>>> ---
>>>>
>>>> Updates in V8:
>>>>  - Adjust the position of matching brackets.
>>>>
>>>> Updates in V6:
>>>>  - Remove unnecessary functions and simplify code.
>>>>
>>>> ---
>>>>
>>>>  drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
>>>>  drivers/mmc/host/sdhci-uhs2.h |  2 ++
>>>>  2 files changed, 47 insertions(+)
>>>>
>>>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
>>>> index e339821d3504..dfc80a7f1bad 100644
>>>> --- a/drivers/mmc/host/sdhci-uhs2.c
>>>> +++ b/drivers/mmc/host/sdhci-uhs2.c
>>>> @@ -10,7 +10,9 @@
>>>>   *  Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
>>>>   */
>>>>
>>>> +#include <linux/delay.h>
>>>>  #include <linux/module.h>
>>>> +#include <linux/iopoll.h>
>>>>
>>>>  #include "sdhci.h"
>>>>  #include "sdhci-uhs2.h"
>>>> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
>>>>  }
>>>>  EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
>>>>
>>>> +/*****************************************************************************\
>>>> + *                                                                           *
>>>> + * Low level functions                                                       *
>>>> + *                                                                           *
>>>> +\*****************************************************************************/
>>>> +
>>>> +bool sdhci_uhs2_mode(struct sdhci_host *host)
>>>> +{
>>>> +       return host->mmc->flags & MMC_UHS2_SUPPORT;
>>>
>>> The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
>>> should be using mmc->ios.timings, which already indicates whether we
>>> are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
>>> this.
>>>
>>> That said, I think we should drop the sdhci_uhs2_mode() function
>>> altogether and instead use mmc_card_uhs2(), which means we should move
>>> it to include/linux/mmc/host.h, so it becomes available for host
>>> drivers.
>>>
>>
>> UHS2 mode starts at UHS2 initialization and ends either when UHS2
>> initialization fails, or the card is removed.
>>
>> So it includes re-initialization and reset when the transfer mode
>> currently transitions through MMC_TIMING_LEGACY.
>>
>> So mmc_card_uhs2() won't work correctly for the host callbacks
>> unless something is done about that.
> 
> Right, thanks for clarifying!
> 
> In that case I wonder if we couldn't change the way we update the
> ->ios.timing for UHS2. It seems silly to have two (similar) ways to
> indicate that we have moved to UHS2.

Perhaps something like below:

diff --git a/drivers/mmc/core/sd_uhs2.c b/drivers/mmc/core/sd_uhs2.c
index aacefdd6bc9e..e39d63d46041 100644
--- a/drivers/mmc/core/sd_uhs2.c
+++ b/drivers/mmc/core/sd_uhs2.c
@@ -70,7 +70,8 @@ static int sd_uhs2_power_off(struct mmc_host *host)
 
 	host->ios.vdd = 0;
 	host->ios.clock = 0;
-	host->ios.timing = MMC_TIMING_LEGACY;
+	/* Must set UHS2 timing to identify UHS2 mode */
+	host->ios.timing = MMC_TIMING_UHS2_SPEED_A;
 	host->ios.power_mode = MMC_POWER_OFF;
 	if (host->flags & MMC_UHS2_SD_TRAN)
 		host->flags &= ~MMC_UHS2_SD_TRAN;
@@ -1095,7 +1096,8 @@ static void sd_uhs2_detect(struct mmc_host *host)
 		mmc_claim_host(host);
 		mmc_detach_bus(host);
 		sd_uhs2_power_off(host);
-		host->flags &= ~MMC_UHS2_SUPPORT;
+		/* Remove UHS2 timing to indicate the end of UHS2 mode */
+		host->ios.timing = MMC_TIMING_LEGACY;
 		mmc_release_host(host);
 	}
 }
@@ -1338,7 +1340,8 @@ static int sd_uhs2_attach(struct mmc_host *host)
 err:
 	mmc_detach_bus(host);
 	sd_uhs2_power_off(host);
-	host->flags &= ~MMC_UHS2_SUPPORT;
+	/* Remove UHS2 timing to indicate the end of UHS2 mode */
+	host->ios.timing = MMC_TIMING_LEGACY;
 	return err;
 }
 
diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
index 517c497112f4..d1f3318b7d3a 100644
--- a/drivers/mmc/host/sdhci-uhs2.c
+++ b/drivers/mmc/host/sdhci-uhs2.c
@@ -267,10 +267,11 @@ static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 
 	/* UHS2 timing. Note, UHS2 timing is disabled when powering off */
 	ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
-	if (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
-	    ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
-	    ios->timing == MMC_TIMING_UHS2_SPEED_B ||
-	    ios->timing == MMC_TIMING_UHS2_SPEED_B_HD)
+	if (ios->power_mode != MMC_POWER_OFF &&
+	    (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
+	     ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
+	     ios->timing == MMC_TIMING_UHS2_SPEED_B ||
+	     ios->timing == MMC_TIMING_UHS2_SPEED_B_HD))
 		ctrl_2 |= SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE;
 	else
 		ctrl_2 &= ~(SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE);
Ulf Hansson Oct. 4, 2023, 8:35 a.m. UTC | #5 
On Tue, 3 Oct 2023 at 17:03, Adrian Hunter <adrian.hunter@intel.com> wrote:
>
> On 3/10/23 15:22, Ulf Hansson wrote:
> > On Tue, 3 Oct 2023 at 13:37, Adrian Hunter <adrian.hunter@intel.com> wrote:
> >>
> >> On 3/10/23 13:30, Ulf Hansson wrote:
> >>> On Fri, 15 Sept 2023 at 11:44, Victor Shih <victorshihgli@gmail.com> wrote:
> >>>>
> >>>> From: Victor Shih <victor.shih@genesyslogic.com.tw>
> >>>>
> >>>> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
> >>>>
> >>>> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> >>>> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> >>>> Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
> >>>> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
> >>>> ---
> >>>>
> >>>> Updates in V8:
> >>>>  - Adjust the position of matching brackets.
> >>>>
> >>>> Updates in V6:
> >>>>  - Remove unnecessary functions and simplify code.
> >>>>
> >>>> ---
> >>>>
> >>>>  drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
> >>>>  drivers/mmc/host/sdhci-uhs2.h |  2 ++
> >>>>  2 files changed, 47 insertions(+)
> >>>>
> >>>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> >>>> index e339821d3504..dfc80a7f1bad 100644
> >>>> --- a/drivers/mmc/host/sdhci-uhs2.c
> >>>> +++ b/drivers/mmc/host/sdhci-uhs2.c
> >>>> @@ -10,7 +10,9 @@
> >>>>   *  Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
> >>>>   */
> >>>>
> >>>> +#include <linux/delay.h>
> >>>>  #include <linux/module.h>
> >>>> +#include <linux/iopoll.h>
> >>>>
> >>>>  #include "sdhci.h"
> >>>>  #include "sdhci-uhs2.h"
> >>>> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> >>>>  }
> >>>>  EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
> >>>>
> >>>> +/*****************************************************************************\
> >>>> + *                                                                           *
> >>>> + * Low level functions                                                       *
> >>>> + *                                                                           *
> >>>> +\*****************************************************************************/
> >>>> +
> >>>> +bool sdhci_uhs2_mode(struct sdhci_host *host)
> >>>> +{
> >>>> +       return host->mmc->flags & MMC_UHS2_SUPPORT;
> >>>
> >>> The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
> >>> should be using mmc->ios.timings, which already indicates whether we
> >>> are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
> >>> this.
> >>>
> >>> That said, I think we should drop the sdhci_uhs2_mode() function
> >>> altogether and instead use mmc_card_uhs2(), which means we should move
> >>> it to include/linux/mmc/host.h, so it becomes available for host
> >>> drivers.
> >>>
> >>
> >> UHS2 mode starts at UHS2 initialization and ends either when UHS2
> >> initialization fails, or the card is removed.
> >>
> >> So it includes re-initialization and reset when the transfer mode
> >> currently transitions through MMC_TIMING_LEGACY.
> >>
> >> So mmc_card_uhs2() won't work correctly for the host callbacks
> >> unless something is done about that.
> >
> > Right, thanks for clarifying!
> >
> > In that case I wonder if we couldn't change the way we update the
> > ->ios.timing for UHS2. It seems silly to have two (similar) ways to
> > indicate that we have moved to UHS2.
>
> Perhaps something like below:
>
> diff --git a/drivers/mmc/core/sd_uhs2.c b/drivers/mmc/core/sd_uhs2.c
> index aacefdd6bc9e..e39d63d46041 100644
> --- a/drivers/mmc/core/sd_uhs2.c
> +++ b/drivers/mmc/core/sd_uhs2.c
> @@ -70,7 +70,8 @@ static int sd_uhs2_power_off(struct mmc_host *host)
>
>         host->ios.vdd = 0;
>         host->ios.clock = 0;
> -       host->ios.timing = MMC_TIMING_LEGACY;
> +       /* Must set UHS2 timing to identify UHS2 mode */
> +       host->ios.timing = MMC_TIMING_UHS2_SPEED_A;
>         host->ios.power_mode = MMC_POWER_OFF;
>         if (host->flags & MMC_UHS2_SD_TRAN)
>                 host->flags &= ~MMC_UHS2_SD_TRAN;
> @@ -1095,7 +1096,8 @@ static void sd_uhs2_detect(struct mmc_host *host)
>                 mmc_claim_host(host);
>                 mmc_detach_bus(host);
>                 sd_uhs2_power_off(host);
> -               host->flags &= ~MMC_UHS2_SUPPORT;
> +               /* Remove UHS2 timing to indicate the end of UHS2 mode */
> +               host->ios.timing = MMC_TIMING_LEGACY;
>                 mmc_release_host(host);
>         }
>  }
> @@ -1338,7 +1340,8 @@ static int sd_uhs2_attach(struct mmc_host *host)
>  err:
>         mmc_detach_bus(host);
>         sd_uhs2_power_off(host);
> -       host->flags &= ~MMC_UHS2_SUPPORT;
> +       /* Remove UHS2 timing to indicate the end of UHS2 mode */
> +       host->ios.timing = MMC_TIMING_LEGACY;
>         return err;
>  }

I wouldn't mind changing to the above. But, maybe an even better
option is to use the ->timing variable in the struct sdhci_host, as
it's there already to keep track of the current/previous timing state.
Would that work too?

>
> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> index 517c497112f4..d1f3318b7d3a 100644
> --- a/drivers/mmc/host/sdhci-uhs2.c
> +++ b/drivers/mmc/host/sdhci-uhs2.c
> @@ -267,10 +267,11 @@ static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>
>         /* UHS2 timing. Note, UHS2 timing is disabled when powering off */
>         ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> -       if (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
> -           ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
> -           ios->timing == MMC_TIMING_UHS2_SPEED_B ||
> -           ios->timing == MMC_TIMING_UHS2_SPEED_B_HD)
> +       if (ios->power_mode != MMC_POWER_OFF &&
> +           (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
> +            ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
> +            ios->timing == MMC_TIMING_UHS2_SPEED_B ||
> +            ios->timing == MMC_TIMING_UHS2_SPEED_B_HD))
>                 ctrl_2 |= SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE;
>         else
>                 ctrl_2 &= ~(SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE);
>
>

Kind regards
Uffe
Adrian Hunter Oct. 10, 2023, 10:29 a.m. UTC | #6 
On 4/10/23 11:35, Ulf Hansson wrote:
> On Tue, 3 Oct 2023 at 17:03, Adrian Hunter <adrian.hunter@intel.com> wrote:
>>
>> On 3/10/23 15:22, Ulf Hansson wrote:
>>> On Tue, 3 Oct 2023 at 13:37, Adrian Hunter <adrian.hunter@intel.com> wrote:
>>>>
>>>> On 3/10/23 13:30, Ulf Hansson wrote:
>>>>> On Fri, 15 Sept 2023 at 11:44, Victor Shih <victorshihgli@gmail.com> wrote:
>>>>>>
>>>>>> From: Victor Shih <victor.shih@genesyslogic.com.tw>
>>>>>>
>>>>>> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
>>>>>>
>>>>>> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
>>>>>> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
>>>>>> Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
>>>>>> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
>>>>>> ---
>>>>>>
>>>>>> Updates in V8:
>>>>>>  - Adjust the position of matching brackets.
>>>>>>
>>>>>> Updates in V6:
>>>>>>  - Remove unnecessary functions and simplify code.
>>>>>>
>>>>>> ---
>>>>>>
>>>>>>  drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
>>>>>>  drivers/mmc/host/sdhci-uhs2.h |  2 ++
>>>>>>  2 files changed, 47 insertions(+)
>>>>>>
>>>>>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
>>>>>> index e339821d3504..dfc80a7f1bad 100644
>>>>>> --- a/drivers/mmc/host/sdhci-uhs2.c
>>>>>> +++ b/drivers/mmc/host/sdhci-uhs2.c
>>>>>> @@ -10,7 +10,9 @@
>>>>>>   *  Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
>>>>>>   */
>>>>>>
>>>>>> +#include <linux/delay.h>
>>>>>>  #include <linux/module.h>
>>>>>> +#include <linux/iopoll.h>
>>>>>>
>>>>>>  #include "sdhci.h"
>>>>>>  #include "sdhci-uhs2.h"
>>>>>> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
>>>>>>  }
>>>>>>  EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
>>>>>>
>>>>>> +/*****************************************************************************\
>>>>>> + *                                                                           *
>>>>>> + * Low level functions                                                       *
>>>>>> + *                                                                           *
>>>>>> +\*****************************************************************************/
>>>>>> +
>>>>>> +bool sdhci_uhs2_mode(struct sdhci_host *host)
>>>>>> +{
>>>>>> +       return host->mmc->flags & MMC_UHS2_SUPPORT;
>>>>>
>>>>> The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
>>>>> should be using mmc->ios.timings, which already indicates whether we
>>>>> are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
>>>>> this.
>>>>>
>>>>> That said, I think we should drop the sdhci_uhs2_mode() function
>>>>> altogether and instead use mmc_card_uhs2(), which means we should move
>>>>> it to include/linux/mmc/host.h, so it becomes available for host
>>>>> drivers.
>>>>>
>>>>
>>>> UHS2 mode starts at UHS2 initialization and ends either when UHS2
>>>> initialization fails, or the card is removed.
>>>>
>>>> So it includes re-initialization and reset when the transfer mode
>>>> currently transitions through MMC_TIMING_LEGACY.
>>>>
>>>> So mmc_card_uhs2() won't work correctly for the host callbacks
>>>> unless something is done about that.
>>>
>>> Right, thanks for clarifying!
>>>
>>> In that case I wonder if we couldn't change the way we update the
>>> ->ios.timing for UHS2. It seems silly to have two (similar) ways to
>>> indicate that we have moved to UHS2.
>>
>> Perhaps something like below:
>>
>> diff --git a/drivers/mmc/core/sd_uhs2.c b/drivers/mmc/core/sd_uhs2.c
>> index aacefdd6bc9e..e39d63d46041 100644
>> --- a/drivers/mmc/core/sd_uhs2.c
>> +++ b/drivers/mmc/core/sd_uhs2.c
>> @@ -70,7 +70,8 @@ static int sd_uhs2_power_off(struct mmc_host *host)
>>
>>         host->ios.vdd = 0;
>>         host->ios.clock = 0;
>> -       host->ios.timing = MMC_TIMING_LEGACY;
>> +       /* Must set UHS2 timing to identify UHS2 mode */
>> +       host->ios.timing = MMC_TIMING_UHS2_SPEED_A;
>>         host->ios.power_mode = MMC_POWER_OFF;
>>         if (host->flags & MMC_UHS2_SD_TRAN)
>>                 host->flags &= ~MMC_UHS2_SD_TRAN;
>> @@ -1095,7 +1096,8 @@ static void sd_uhs2_detect(struct mmc_host *host)
>>                 mmc_claim_host(host);
>>                 mmc_detach_bus(host);
>>                 sd_uhs2_power_off(host);
>> -               host->flags &= ~MMC_UHS2_SUPPORT;
>> +               /* Remove UHS2 timing to indicate the end of UHS2 mode */
>> +               host->ios.timing = MMC_TIMING_LEGACY;
>>                 mmc_release_host(host);
>>         }
>>  }
>> @@ -1338,7 +1340,8 @@ static int sd_uhs2_attach(struct mmc_host *host)
>>  err:
>>         mmc_detach_bus(host);
>>         sd_uhs2_power_off(host);
>> -       host->flags &= ~MMC_UHS2_SUPPORT;
>> +       /* Remove UHS2 timing to indicate the end of UHS2 mode */
>> +       host->ios.timing = MMC_TIMING_LEGACY;
>>         return err;
>>  }
> 
> I wouldn't mind changing to the above. But, maybe an even better
> option is to use the ->timing variable in the struct sdhci_host, as
> it's there already to keep track of the current/previous timing state.
> Would that work too?

The host does not really have enough information.

> 
>>
>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
>> index 517c497112f4..d1f3318b7d3a 100644
>> --- a/drivers/mmc/host/sdhci-uhs2.c
>> +++ b/drivers/mmc/host/sdhci-uhs2.c
>> @@ -267,10 +267,11 @@ static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>>
>>         /* UHS2 timing. Note, UHS2 timing is disabled when powering off */
>>         ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
>> -       if (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
>> -           ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
>> -           ios->timing == MMC_TIMING_UHS2_SPEED_B ||
>> -           ios->timing == MMC_TIMING_UHS2_SPEED_B_HD)
>> +       if (ios->power_mode != MMC_POWER_OFF &&
>> +           (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
>> +            ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
>> +            ios->timing == MMC_TIMING_UHS2_SPEED_B ||
>> +            ios->timing == MMC_TIMING_UHS2_SPEED_B_HD))
>>                 ctrl_2 |= SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE;
>>         else
>>                 ctrl_2 &= ~(SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE);
>>
>>
> 
> Kind regards
> Uffe
Ulf Hansson Oct. 10, 2023, 11:08 a.m. UTC | #7 
On Tue, 10 Oct 2023 at 12:29, Adrian Hunter <adrian.hunter@intel.com> wrote:
>
> On 4/10/23 11:35, Ulf Hansson wrote:
> > On Tue, 3 Oct 2023 at 17:03, Adrian Hunter <adrian.hunter@intel.com> wrote:
> >>
> >> On 3/10/23 15:22, Ulf Hansson wrote:
> >>> On Tue, 3 Oct 2023 at 13:37, Adrian Hunter <adrian.hunter@intel.com> wrote:
> >>>>
> >>>> On 3/10/23 13:30, Ulf Hansson wrote:
> >>>>> On Fri, 15 Sept 2023 at 11:44, Victor Shih <victorshihgli@gmail.com> wrote:
> >>>>>>
> >>>>>> From: Victor Shih <victor.shih@genesyslogic.com.tw>
> >>>>>>
> >>>>>> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
> >>>>>>
> >>>>>> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> >>>>>> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> >>>>>> Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
> >>>>>> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
> >>>>>> ---
> >>>>>>
> >>>>>> Updates in V8:
> >>>>>>  - Adjust the position of matching brackets.
> >>>>>>
> >>>>>> Updates in V6:
> >>>>>>  - Remove unnecessary functions and simplify code.
> >>>>>>
> >>>>>> ---
> >>>>>>
> >>>>>>  drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
> >>>>>>  drivers/mmc/host/sdhci-uhs2.h |  2 ++
> >>>>>>  2 files changed, 47 insertions(+)
> >>>>>>
> >>>>>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> >>>>>> index e339821d3504..dfc80a7f1bad 100644
> >>>>>> --- a/drivers/mmc/host/sdhci-uhs2.c
> >>>>>> +++ b/drivers/mmc/host/sdhci-uhs2.c
> >>>>>> @@ -10,7 +10,9 @@
> >>>>>>   *  Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
> >>>>>>   */
> >>>>>>
> >>>>>> +#include <linux/delay.h>
> >>>>>>  #include <linux/module.h>
> >>>>>> +#include <linux/iopoll.h>
> >>>>>>
> >>>>>>  #include "sdhci.h"
> >>>>>>  #include "sdhci-uhs2.h"
> >>>>>> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> >>>>>>  }
> >>>>>>  EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
> >>>>>>
> >>>>>> +/*****************************************************************************\
> >>>>>> + *                                                                           *
> >>>>>> + * Low level functions                                                       *
> >>>>>> + *                                                                           *
> >>>>>> +\*****************************************************************************/
> >>>>>> +
> >>>>>> +bool sdhci_uhs2_mode(struct sdhci_host *host)
> >>>>>> +{
> >>>>>> +       return host->mmc->flags & MMC_UHS2_SUPPORT;
> >>>>>
> >>>>> The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
> >>>>> should be using mmc->ios.timings, which already indicates whether we
> >>>>> are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
> >>>>> this.
> >>>>>
> >>>>> That said, I think we should drop the sdhci_uhs2_mode() function
> >>>>> altogether and instead use mmc_card_uhs2(), which means we should move
> >>>>> it to include/linux/mmc/host.h, so it becomes available for host
> >>>>> drivers.
> >>>>>
> >>>>
> >>>> UHS2 mode starts at UHS2 initialization and ends either when UHS2
> >>>> initialization fails, or the card is removed.
> >>>>
> >>>> So it includes re-initialization and reset when the transfer mode
> >>>> currently transitions through MMC_TIMING_LEGACY.
> >>>>
> >>>> So mmc_card_uhs2() won't work correctly for the host callbacks
> >>>> unless something is done about that.
> >>>
> >>> Right, thanks for clarifying!
> >>>
> >>> In that case I wonder if we couldn't change the way we update the
> >>> ->ios.timing for UHS2. It seems silly to have two (similar) ways to
> >>> indicate that we have moved to UHS2.
> >>
> >> Perhaps something like below:
> >>
> >> diff --git a/drivers/mmc/core/sd_uhs2.c b/drivers/mmc/core/sd_uhs2.c
> >> index aacefdd6bc9e..e39d63d46041 100644
> >> --- a/drivers/mmc/core/sd_uhs2.c
> >> +++ b/drivers/mmc/core/sd_uhs2.c
> >> @@ -70,7 +70,8 @@ static int sd_uhs2_power_off(struct mmc_host *host)
> >>
> >>         host->ios.vdd = 0;
> >>         host->ios.clock = 0;
> >> -       host->ios.timing = MMC_TIMING_LEGACY;
> >> +       /* Must set UHS2 timing to identify UHS2 mode */
> >> +       host->ios.timing = MMC_TIMING_UHS2_SPEED_A;
> >>         host->ios.power_mode = MMC_POWER_OFF;
> >>         if (host->flags & MMC_UHS2_SD_TRAN)
> >>                 host->flags &= ~MMC_UHS2_SD_TRAN;
> >> @@ -1095,7 +1096,8 @@ static void sd_uhs2_detect(struct mmc_host *host)
> >>                 mmc_claim_host(host);
> >>                 mmc_detach_bus(host);
> >>                 sd_uhs2_power_off(host);
> >> -               host->flags &= ~MMC_UHS2_SUPPORT;
> >> +               /* Remove UHS2 timing to indicate the end of UHS2 mode */
> >> +               host->ios.timing = MMC_TIMING_LEGACY;
> >>                 mmc_release_host(host);
> >>         }
> >>  }
> >> @@ -1338,7 +1340,8 @@ static int sd_uhs2_attach(struct mmc_host *host)
> >>  err:
> >>         mmc_detach_bus(host);
> >>         sd_uhs2_power_off(host);
> >> -       host->flags &= ~MMC_UHS2_SUPPORT;
> >> +       /* Remove UHS2 timing to indicate the end of UHS2 mode */
> >> +       host->ios.timing = MMC_TIMING_LEGACY;
> >>         return err;
> >>  }
> >
> > I wouldn't mind changing to the above. But, maybe an even better
> > option is to use the ->timing variable in the struct sdhci_host, as
> > it's there already to keep track of the current/previous timing state.
> > Would that work too?
>
> The host does not really have enough information.

Okay, let's go with the approach you suggested above/below then!

>
> >
> >>
> >> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> >> index 517c497112f4..d1f3318b7d3a 100644
> >> --- a/drivers/mmc/host/sdhci-uhs2.c
> >> +++ b/drivers/mmc/host/sdhci-uhs2.c
> >> @@ -267,10 +267,11 @@ static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> >>
> >>         /* UHS2 timing. Note, UHS2 timing is disabled when powering off */
> >>         ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> >> -       if (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
> >> -           ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
> >> -           ios->timing == MMC_TIMING_UHS2_SPEED_B ||
> >> -           ios->timing == MMC_TIMING_UHS2_SPEED_B_HD)
> >> +       if (ios->power_mode != MMC_POWER_OFF &&
> >> +           (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
> >> +            ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
> >> +            ios->timing == MMC_TIMING_UHS2_SPEED_B ||
> >> +            ios->timing == MMC_TIMING_UHS2_SPEED_B_HD))
> >>                 ctrl_2 |= SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE;
> >>         else
> >>                 ctrl_2 &= ~(SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE);
> >>
> >>

Kind regards
Uffe
Victor Shih Nov. 17, 2023, 10:49 a.m. UTC | #8 
On Tue, Oct 10, 2023 at 7:08 PM Ulf Hansson <ulf.hansson@linaro.org> wrote:
>
> On Tue, 10 Oct 2023 at 12:29, Adrian Hunter <adrian.hunter@intel.com> wrote:
> >
> > On 4/10/23 11:35, Ulf Hansson wrote:
> > > On Tue, 3 Oct 2023 at 17:03, Adrian Hunter <adrian.hunter@intel.com> wrote:
> > >>
> > >> On 3/10/23 15:22, Ulf Hansson wrote:
> > >>> On Tue, 3 Oct 2023 at 13:37, Adrian Hunter <adrian.hunter@intel.com> wrote:
> > >>>>
> > >>>> On 3/10/23 13:30, Ulf Hansson wrote:
> > >>>>> On Fri, 15 Sept 2023 at 11:44, Victor Shih <victorshihgli@gmail.com> wrote:
> > >>>>>>
> > >>>>>> From: Victor Shih <victor.shih@genesyslogic.com.tw>
> > >>>>>>
> > >>>>>> Sdhci_uhs2_reset() does a UHS-II specific reset operation.
> > >>>>>>
> > >>>>>> Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
> > >>>>>> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > >>>>>> Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
> > >>>>>> Acked-by: Adrian Hunter <adrian.hunter@intel.com>
> > >>>>>> ---
> > >>>>>>
> > >>>>>> Updates in V8:
> > >>>>>>  - Adjust the position of matching brackets.
> > >>>>>>
> > >>>>>> Updates in V6:
> > >>>>>>  - Remove unnecessary functions and simplify code.
> > >>>>>>
> > >>>>>> ---
> > >>>>>>
> > >>>>>>  drivers/mmc/host/sdhci-uhs2.c | 45 +++++++++++++++++++++++++++++++++++
> > >>>>>>  drivers/mmc/host/sdhci-uhs2.h |  2 ++
> > >>>>>>  2 files changed, 47 insertions(+)
> > >>>>>>
> > >>>>>> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> > >>>>>> index e339821d3504..dfc80a7f1bad 100644
> > >>>>>> --- a/drivers/mmc/host/sdhci-uhs2.c
> > >>>>>> +++ b/drivers/mmc/host/sdhci-uhs2.c
> > >>>>>> @@ -10,7 +10,9 @@
> > >>>>>>   *  Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
> > >>>>>>   */
> > >>>>>>
> > >>>>>> +#include <linux/delay.h>
> > >>>>>>  #include <linux/module.h>
> > >>>>>> +#include <linux/iopoll.h>
> > >>>>>>
> > >>>>>>  #include "sdhci.h"
> > >>>>>>  #include "sdhci-uhs2.h"
> > >>>>>> @@ -49,6 +51,49 @@ void sdhci_uhs2_dump_regs(struct sdhci_host *host)
> > >>>>>>  }
> > >>>>>>  EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
> > >>>>>>
> > >>>>>> +/*****************************************************************************\
> > >>>>>> + *                                                                           *
> > >>>>>> + * Low level functions                                                       *
> > >>>>>> + *                                                                           *
> > >>>>>> +\*****************************************************************************/
> > >>>>>> +
> > >>>>>> +bool sdhci_uhs2_mode(struct sdhci_host *host)
> > >>>>>> +{
> > >>>>>> +       return host->mmc->flags & MMC_UHS2_SUPPORT;
> > >>>>>
> > >>>>> The MMC_UHS2_SUPPORT bit looks redundant to me. Instead, I think we
> > >>>>> should be using mmc->ios.timings, which already indicates whether we
> > >>>>> are using UHS2 (MMC_TIMING_UHS2_SPEED_*). See patch2 where we added
> > >>>>> this.
> > >>>>>
> > >>>>> That said, I think we should drop the sdhci_uhs2_mode() function
> > >>>>> altogether and instead use mmc_card_uhs2(), which means we should move
> > >>>>> it to include/linux/mmc/host.h, so it becomes available for host
> > >>>>> drivers.
> > >>>>>
> > >>>>
> > >>>> UHS2 mode starts at UHS2 initialization and ends either when UHS2
> > >>>> initialization fails, or the card is removed.
> > >>>>
> > >>>> So it includes re-initialization and reset when the transfer mode
> > >>>> currently transitions through MMC_TIMING_LEGACY.
> > >>>>
> > >>>> So mmc_card_uhs2() won't work correctly for the host callbacks
> > >>>> unless something is done about that.
> > >>>
> > >>> Right, thanks for clarifying!
> > >>>
> > >>> In that case I wonder if we couldn't change the way we update the
> > >>> ->ios.timing for UHS2. It seems silly to have two (similar) ways to
> > >>> indicate that we have moved to UHS2.
> > >>
> > >> Perhaps something like below:
> > >>
> > >> diff --git a/drivers/mmc/core/sd_uhs2.c b/drivers/mmc/core/sd_uhs2.c
> > >> index aacefdd6bc9e..e39d63d46041 100644
> > >> --- a/drivers/mmc/core/sd_uhs2.c
> > >> +++ b/drivers/mmc/core/sd_uhs2.c
> > >> @@ -70,7 +70,8 @@ static int sd_uhs2_power_off(struct mmc_host *host)
> > >>
> > >>         host->ios.vdd = 0;
> > >>         host->ios.clock = 0;
> > >> -       host->ios.timing = MMC_TIMING_LEGACY;
> > >> +       /* Must set UHS2 timing to identify UHS2 mode */
> > >> +       host->ios.timing = MMC_TIMING_UHS2_SPEED_A;
> > >>         host->ios.power_mode = MMC_POWER_OFF;
> > >>         if (host->flags & MMC_UHS2_SD_TRAN)
> > >>                 host->flags &= ~MMC_UHS2_SD_TRAN;
> > >> @@ -1095,7 +1096,8 @@ static void sd_uhs2_detect(struct mmc_host *host)
> > >>                 mmc_claim_host(host);
> > >>                 mmc_detach_bus(host);
> > >>                 sd_uhs2_power_off(host);
> > >> -               host->flags &= ~MMC_UHS2_SUPPORT;
> > >> +               /* Remove UHS2 timing to indicate the end of UHS2 mode */
> > >> +               host->ios.timing = MMC_TIMING_LEGACY;
> > >>                 mmc_release_host(host);
> > >>         }
> > >>  }
> > >> @@ -1338,7 +1340,8 @@ static int sd_uhs2_attach(struct mmc_host *host)
> > >>  err:
> > >>         mmc_detach_bus(host);
> > >>         sd_uhs2_power_off(host);
> > >> -       host->flags &= ~MMC_UHS2_SUPPORT;
> > >> +       /* Remove UHS2 timing to indicate the end of UHS2 mode */
> > >> +       host->ios.timing = MMC_TIMING_LEGACY;
> > >>         return err;
> > >>  }
> > >
> > > I wouldn't mind changing to the above. But, maybe an even better
> > > option is to use the ->timing variable in the struct sdhci_host, as
> > > it's there already to keep track of the current/previous timing state.
> > > Would that work too?
> >
> > The host does not really have enough information.
>
> Okay, let's go with the approach you suggested above/below then!
>

Hi, Ulf and Adrian

I will update this in version 13.

Thanks, Victor Shih

> >
> > >
> > >>
> > >> diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
> > >> index 517c497112f4..d1f3318b7d3a 100644
> > >> --- a/drivers/mmc/host/sdhci-uhs2.c
> > >> +++ b/drivers/mmc/host/sdhci-uhs2.c
> > >> @@ -267,10 +267,11 @@ static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> > >>
> > >>         /* UHS2 timing. Note, UHS2 timing is disabled when powering off */
> > >>         ctrl_2 = sdhci_readw(host, SDHCI_HOST_CONTROL2);
> > >> -       if (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
> > >> -           ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
> > >> -           ios->timing == MMC_TIMING_UHS2_SPEED_B ||
> > >> -           ios->timing == MMC_TIMING_UHS2_SPEED_B_HD)
> > >> +       if (ios->power_mode != MMC_POWER_OFF &&
> > >> +           (ios->timing == MMC_TIMING_UHS2_SPEED_A ||
> > >> +            ios->timing == MMC_TIMING_UHS2_SPEED_A_HD ||
> > >> +            ios->timing == MMC_TIMING_UHS2_SPEED_B ||
> > >> +            ios->timing == MMC_TIMING_UHS2_SPEED_B_HD))
> > >>                 ctrl_2 |= SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE;
> > >>         else
> > >>                 ctrl_2 &= ~(SDHCI_CTRL_UHS2 | SDHCI_CTRL_UHS2_ENABLE);
> > >>
> > >>
>
> Kind regards
> Uffe
diff mbox series

Patch

diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
index e339821d3504..dfc80a7f1bad 100644
--- a/drivers/mmc/host/sdhci-uhs2.c
+++ b/drivers/mmc/host/sdhci-uhs2.c
@@ -10,7 +10,9 @@ 
  *  Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
  */
 
+#include <linux/delay.h>
 #include <linux/module.h>
+#include <linux/iopoll.h>
 
 #include "sdhci.h"
 #include "sdhci-uhs2.h"
@@ -49,6 +51,49 @@  void sdhci_uhs2_dump_regs(struct sdhci_host *host)
 }
 EXPORT_SYMBOL_GPL(sdhci_uhs2_dump_regs);
 
+/*****************************************************************************\
+ *                                                                           *
+ * Low level functions                                                       *
+ *                                                                           *
+\*****************************************************************************/
+
+bool sdhci_uhs2_mode(struct sdhci_host *host)
+{
+	return host->mmc->flags & MMC_UHS2_SUPPORT;
+}
+
+/**
+ * sdhci_uhs2_reset - invoke SW reset
+ * @host: SDHCI host
+ * @mask: Control mask
+ *
+ * Invoke SW reset, depending on a bit in @mask and wait for completion.
+ */
+void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask)
+{
+	unsigned long timeout;
+	u32 val;
+
+	sdhci_writew(host, mask, SDHCI_UHS2_SW_RESET);
+
+	if (mask & SDHCI_UHS2_SW_RESET_FULL)
+		host->clock = 0;
+
+	/* Wait max 100 ms */
+	timeout = 100000;
+
+	/* hw clears the bit when it's done */
+	if (read_poll_timeout_atomic(sdhci_readw, val, !(val & mask), 10,
+				     timeout, true, host, SDHCI_UHS2_SW_RESET)) {
+		pr_err("%s: %s: Reset 0x%x never completed.\n", __func__,
+		       mmc_hostname(host->mmc), (int)mask);
+		pr_err("%s: clean reset bit\n", mmc_hostname(host->mmc));
+		sdhci_writeb(host, 0, SDHCI_UHS2_SW_RESET);
+		return;
+	}
+}
+EXPORT_SYMBOL_GPL(sdhci_uhs2_reset);
+
 /*****************************************************************************\
  *                                                                           *
  * Driver init/exit                                                          *
diff --git a/drivers/mmc/host/sdhci-uhs2.h b/drivers/mmc/host/sdhci-uhs2.h
index 2bfe18d29bca..8253d50f7852 100644
--- a/drivers/mmc/host/sdhci-uhs2.h
+++ b/drivers/mmc/host/sdhci-uhs2.h
@@ -177,5 +177,7 @@ 
 struct sdhci_host;
 
 void sdhci_uhs2_dump_regs(struct sdhci_host *host);
+bool sdhci_uhs2_mode(struct sdhci_host *host);
+void sdhci_uhs2_reset(struct sdhci_host *host, u16 mask);
 
 #endif /* __SDHCI_UHS2_H */