* [PATCH 1/2] mmc: dw_mmc: retry to switch voltage when failed
@ 2016-05-04 7:14 Jaehoon Chung
2016-05-04 7:14 ` [PATCH 2/2] mmc: dw_mmc: prevent to set the wrong value Jaehoon Chung
2016-05-04 10:41 ` [PATCH 1/2] mmc: dw_mmc: retry to switch voltage when failed Shawn Lin
0 siblings, 2 replies; 8+ messages in thread
From: Jaehoon Chung @ 2016-05-04 7:14 UTC (permalink / raw)
To: linux-mmc; +Cc: ulf.hansson, shawn.lin, Jaehoon Chung
If vqmmc is used and failed to switch voltage, then retry to switch
voltage. MMC core is providing the retrying scheame.
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
---
drivers/mmc/host/dw_mmc.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 9dd1bd3..28602cc 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1416,7 +1416,7 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
dev_dbg(&mmc->class_dev,
"Regulator set error %d - %s V\n",
ret, uhs & v18 ? "1.8" : "3.3");
- return ret;
+ return -EAGAIN;
}
}
mci_writel(host, UHS_REG, uhs);
--
1.9.1
^ permalink raw reply related [flat|nested] 8+ messages in thread
* [PATCH 2/2] mmc: dw_mmc: prevent to set the wrong value
2016-05-04 7:14 [PATCH 1/2] mmc: dw_mmc: retry to switch voltage when failed Jaehoon Chung
@ 2016-05-04 7:14 ` Jaehoon Chung
2016-05-04 10:35 ` Shawn Lin
2016-05-04 10:41 ` [PATCH 1/2] mmc: dw_mmc: retry to switch voltage when failed Shawn Lin
1 sibling, 1 reply; 8+ messages in thread
From: Jaehoon Chung @ 2016-05-04 7:14 UTC (permalink / raw)
To: linux-mmc; +Cc: ulf.hansson, shawn.lin, Jaehoon Chung
If there is no vqmmc, real voltage should not change.
Then it needs to maintain the previous status for UHS_REG register.
It means that it doesn't need to set any bit.
Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
---
drivers/mmc/host/dw_mmc.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
index 28602cc..6bd8018 100644
--- a/drivers/mmc/host/dw_mmc.c
+++ b/drivers/mmc/host/dw_mmc.c
@@ -1418,7 +1418,19 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
ret, uhs & v18 ? "1.8" : "3.3");
return -EAGAIN;
}
+ } else {
+ /*
+ * If there isn't vqmmc, it should fail to switch voltage.
+ * Then it needs to maintain the previous status.
+ * If ios->signal_voltage is 3.3v, it means that previous
+ * voltages was 1.8v.
+ */
+ if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
+ uhs |= v18;
+ else
+ uhs &= ~v18;
}
+
mci_writel(host, UHS_REG, uhs);
return 0;
--
1.9.1
^ permalink raw reply related [flat|nested] 8+ messages in thread* Re: [PATCH 2/2] mmc: dw_mmc: prevent to set the wrong value
2016-05-04 7:14 ` [PATCH 2/2] mmc: dw_mmc: prevent to set the wrong value Jaehoon Chung
@ 2016-05-04 10:35 ` Shawn Lin
2016-05-10 1:49 ` Jaehoon Chung
0 siblings, 1 reply; 8+ messages in thread
From: Shawn Lin @ 2016-05-04 10:35 UTC (permalink / raw)
To: Jaehoon Chung, linux-mmc; +Cc: shawn.lin, ulf.hansson
在 2016/5/4 15:14, Jaehoon Chung 写道:
> If there is no vqmmc, real voltage should not change.
> Then it needs to maintain the previous status for UHS_REG register.
> It means that it doesn't need to set any bit.
>
> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
> ---
> drivers/mmc/host/dw_mmc.c | 12 ++++++++++++
> 1 file changed, 12 insertions(+)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 28602cc..6bd8018 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1418,7 +1418,19 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
> ret, uhs & v18 ? "1.8" : "3.3");
> return -EAGAIN;
> }
> + } else {
> + /*
> + * If there isn't vqmmc, it should fail to switch voltage.
> + * Then it needs to maintain the previous status.
> + * If ios->signal_voltage is 3.3v, it means that previous
> + * voltages was 1.8v.
> + */
> + if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
> + uhs |= v18;
> + else
> + uhs &= ~v18;
I think we can just set uhs after seting vqmmc correctly. So
how about changing like this?
uhs = mci_readl(host, UHS_REG);
if (!IS_ERR(mmc->supply.vqmmc)) {
ret = mmc_regulator_set_vqmmc(mmc, ios);
if (ret) {
dev_dbg(&mmc->class_dev,
"Regulator set error %d - %s V\n",
ret, uhs & v18 ? "3.3" : "1.8");
return -EAGAIN;
}
if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
uhs &= ~v18;
else
uhs |= v18;
}
mci_writel(host, UHS_REG, uhs);
> }
> +
> mci_writel(host, UHS_REG, uhs);
>
> return 0;
>
--
Best Regards
Shawn Lin
^ permalink raw reply [flat|nested] 8+ messages in thread* Re: [PATCH 2/2] mmc: dw_mmc: prevent to set the wrong value
2016-05-04 10:35 ` Shawn Lin
@ 2016-05-10 1:49 ` Jaehoon Chung
0 siblings, 0 replies; 8+ messages in thread
From: Jaehoon Chung @ 2016-05-10 1:49 UTC (permalink / raw)
To: Shawn Lin, linux-mmc; +Cc: ulf.hansson
Hi Shawn,
On 05/04/2016 07:35 PM, Shawn Lin wrote:
> 在 2016/5/4 15:14, Jaehoon Chung 写道:
>> If there is no vqmmc, real voltage should not change.
>> Then it needs to maintain the previous status for UHS_REG register.
>> It means that it doesn't need to set any bit.
>>
>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>> ---
>> drivers/mmc/host/dw_mmc.c | 12 ++++++++++++
>> 1 file changed, 12 insertions(+)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index 28602cc..6bd8018 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -1418,7 +1418,19 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
>> ret, uhs & v18 ? "1.8" : "3.3");
>> return -EAGAIN;
>> }
>> + } else {
>> + /*
>> + * If there isn't vqmmc, it should fail to switch voltage.
>> + * Then it needs to maintain the previous status.
>> + * If ios->signal_voltage is 3.3v, it means that previous
>> + * voltages was 1.8v.
>> + */
>> + if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
>> + uhs |= v18;
>> + else
>> + uhs &= ~v18;
>
> I think we can just set uhs after seting vqmmc correctly. So
> how about changing like this?
Yes, it's more readable than mine. Thanks.
Best Regards,
Jaehoon Chung
>
> uhs = mci_readl(host, UHS_REG);
>
> if (!IS_ERR(mmc->supply.vqmmc)) {
> ret = mmc_regulator_set_vqmmc(mmc, ios);
> if (ret) {
> dev_dbg(&mmc->class_dev,
> "Regulator set error %d - %s V\n",
> ret, uhs & v18 ? "3.3" : "1.8");
> return -EAGAIN;
> }
> if (ios->signal_voltage == MMC_SIGNAL_VOLTAGE_330)
> uhs &= ~v18;
> else
> uhs |= v18;
> }
> mci_writel(host, UHS_REG, uhs);
>
>
>> }
>> +
>> mci_writel(host, UHS_REG, uhs);
>>
>> return 0;
>>
>
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/2] mmc: dw_mmc: retry to switch voltage when failed
2016-05-04 7:14 [PATCH 1/2] mmc: dw_mmc: retry to switch voltage when failed Jaehoon Chung
2016-05-04 7:14 ` [PATCH 2/2] mmc: dw_mmc: prevent to set the wrong value Jaehoon Chung
@ 2016-05-04 10:41 ` Shawn Lin
2016-05-10 1:55 ` Jaehoon Chung
1 sibling, 1 reply; 8+ messages in thread
From: Shawn Lin @ 2016-05-04 10:41 UTC (permalink / raw)
To: Jaehoon Chung, linux-mmc; +Cc: shawn.lin, ulf.hansson
在 2016/5/4 15:14, Jaehoon Chung 写道:
> If vqmmc is used and failed to switch voltage, then retry to switch
> voltage. MMC core is providing the retrying scheame.
>
> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
> ---
> drivers/mmc/host/dw_mmc.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
> index 9dd1bd3..28602cc 100644
> --- a/drivers/mmc/host/dw_mmc.c
> +++ b/drivers/mmc/host/dw_mmc.c
> @@ -1416,7 +1416,7 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
> dev_dbg(&mmc->class_dev,
> "Regulator set error %d - %s V\n",
> ret, uhs & v18 ? "1.8" : "3.3");
> - return ret;
> + return -EAGAIN;
> }
> }
If not vqmmc is assigned, dw_mci_switch_voltage still returns success to
mmc core?
> mci_writel(host, UHS_REG, uhs);
>
--
Best Regards
Shawn Lin
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/2] mmc: dw_mmc: retry to switch voltage when failed
2016-05-04 10:41 ` [PATCH 1/2] mmc: dw_mmc: retry to switch voltage when failed Shawn Lin
@ 2016-05-10 1:55 ` Jaehoon Chung
2016-05-10 9:24 ` Shawn Lin
0 siblings, 1 reply; 8+ messages in thread
From: Jaehoon Chung @ 2016-05-10 1:55 UTC (permalink / raw)
To: Shawn Lin, linux-mmc; +Cc: ulf.hansson
Hi Shawn,
On 05/04/2016 07:41 PM, Shawn Lin wrote:
> 在 2016/5/4 15:14, Jaehoon Chung 写道:
>> If vqmmc is used and failed to switch voltage, then retry to switch
>> voltage. MMC core is providing the retrying scheame.
>>
>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>> ---
>> drivers/mmc/host/dw_mmc.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>> index 9dd1bd3..28602cc 100644
>> --- a/drivers/mmc/host/dw_mmc.c
>> +++ b/drivers/mmc/host/dw_mmc.c
>> @@ -1416,7 +1416,7 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
>> dev_dbg(&mmc->class_dev,
>> "Regulator set error %d - %s V\n",
>> ret, uhs & v18 ? "1.8" : "3.3");
>> - return ret;
>> + return -EAGAIN;
>> }
>> }
>
> If not vqmmc is assigned, dw_mci_switch_voltage still returns success to
> mmc core?
There is comment in dw_mci_switch_voltage().. In some SoC, it's not harmful to switch voltage.
But we can decide this condition whether try to set both or not.
Best Regards,
Jaehoon Chung
>
>> mci_writel(host, UHS_REG, uhs);
>>
>
>
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: [PATCH 1/2] mmc: dw_mmc: retry to switch voltage when failed
2016-05-10 1:55 ` Jaehoon Chung
@ 2016-05-10 9:24 ` Shawn Lin
2016-05-11 2:51 ` Jaehoon Chung
0 siblings, 1 reply; 8+ messages in thread
From: Shawn Lin @ 2016-05-10 9:24 UTC (permalink / raw)
To: Jaehoon Chung, Shawn Lin, linux-mmc; +Cc: shawn.lin, ulf.hansson
On 2016/5/10 9:55, Jaehoon Chung wrote:
> Hi Shawn,
>
> On 05/04/2016 07:41 PM, Shawn Lin wrote:
>> 在 2016/5/4 15:14, Jaehoon Chung 写道:
>>> If vqmmc is used and failed to switch voltage, then retry to switch
>>> voltage. MMC core is providing the retrying scheame.
>>>
>>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>>> ---
>>> drivers/mmc/host/dw_mmc.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>> index 9dd1bd3..28602cc 100644
>>> --- a/drivers/mmc/host/dw_mmc.c
>>> +++ b/drivers/mmc/host/dw_mmc.c
>>> @@ -1416,7 +1416,7 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
>>> dev_dbg(&mmc->class_dev,
>>> "Regulator set error %d - %s V\n",
>>> ret, uhs & v18 ? "1.8" : "3.3");
>>> - return ret;
>>> + return -EAGAIN;
>>> }
>>> }
>>
>> If not vqmmc is assigned, dw_mci_switch_voltage still returns success to
>> mmc core?
>
> There is comment in dw_mci_switch_voltage().. In some SoC, it's not harmful to switch voltage.
> But we can decide this condition whether try to set both or not.
Because for dw_mmc-rockchip, we always need to swicth voltage by
regulator. So do you mean some exynos Socs can switch voltage just
by setting UHS_REG!? So to make things safe, we can set UHS_REG and
switch voltage by regulator both?
>
> Best Regards,
> Jaehoon Chung
>
>>
>>> mci_writel(host, UHS_REG, uhs);
>>>
>>
>>
>
> --
> 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] 8+ messages in thread
* Re: [PATCH 1/2] mmc: dw_mmc: retry to switch voltage when failed
2016-05-10 9:24 ` Shawn Lin
@ 2016-05-11 2:51 ` Jaehoon Chung
0 siblings, 0 replies; 8+ messages in thread
From: Jaehoon Chung @ 2016-05-11 2:51 UTC (permalink / raw)
To: Shawn Lin, Shawn Lin, linux-mmc; +Cc: ulf.hansson
On 05/10/2016 06:24 PM, Shawn Lin wrote:
> On 2016/5/10 9:55, Jaehoon Chung wrote:
>> Hi Shawn,
>>
>> On 05/04/2016 07:41 PM, Shawn Lin wrote:
>>> 在 2016/5/4 15:14, Jaehoon Chung 写道:
>>>> If vqmmc is used and failed to switch voltage, then retry to switch
>>>> voltage. MMC core is providing the retrying scheame.
>>>>
>>>> Signed-off-by: Jaehoon Chung <jh80.chung@samsung.com>
>>>> ---
>>>> drivers/mmc/host/dw_mmc.c | 2 +-
>>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>>
>>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>>> index 9dd1bd3..28602cc 100644
>>>> --- a/drivers/mmc/host/dw_mmc.c
>>>> +++ b/drivers/mmc/host/dw_mmc.c
>>>> @@ -1416,7 +1416,7 @@ static int dw_mci_switch_voltage(struct mmc_host *mmc, struct mmc_ios *ios)
>>>> dev_dbg(&mmc->class_dev,
>>>> "Regulator set error %d - %s V\n",
>>>> ret, uhs & v18 ? "1.8" : "3.3");
>>>> - return ret;
>>>> + return -EAGAIN;
>>>> }
>>>> }
>>>
>>> If not vqmmc is assigned, dw_mci_switch_voltage still returns success to
>>> mmc core?
>>
>> There is comment in dw_mci_switch_voltage().. In some SoC, it's not harmful to switch voltage.
>> But we can decide this condition whether try to set both or not.
>
>
> Because for dw_mmc-rockchip, we always need to swicth voltage by
> regulator. So do you mean some exynos Socs can switch voltage just
> by setting UHS_REG!? So to make things safe, we can set UHS_REG and
> switch voltage by regulator both?
Ok. I will update the patch.
Best Regards,
Jaehoon Chung
>
>
>
>>
>> Best Regards,
>> Jaehoon Chung
>>
>>>
>>>> mci_writel(host, UHS_REG, uhs);
>>>>
>>>
>>>
>>
>> --
>> 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
>>
>
> --
> 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] 8+ messages in thread
end of thread, other threads:[~2016-05-11 2:51 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2016-05-04 7:14 [PATCH 1/2] mmc: dw_mmc: retry to switch voltage when failed Jaehoon Chung
2016-05-04 7:14 ` [PATCH 2/2] mmc: dw_mmc: prevent to set the wrong value Jaehoon Chung
2016-05-04 10:35 ` Shawn Lin
2016-05-10 1:49 ` Jaehoon Chung
2016-05-04 10:41 ` [PATCH 1/2] mmc: dw_mmc: retry to switch voltage when failed Shawn Lin
2016-05-10 1:55 ` Jaehoon Chung
2016-05-10 9:24 ` Shawn Lin
2016-05-11 2:51 ` Jaehoon Chung
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