On 03/11/17 11:23, Shah, Nehal-bakulchandra wrote:
> Hi Adrian
>
> On 10/19/2017 3:32 PM, Adrian Hunter wrote:
>> On 12/10/17 13:32, Shah, Nehal-bakulchandra wrote:
>>> From: Shah Nehal-Bakulchandra <Nehal-bakulchandra.Shah@xxxxxxx>
>>>
>>> This patch supports HS400 for AMD upcoming emmc 5.0 controller.The
>>> HS400 and HS200 mode requires hardware work around also. This patch
>>> adds the quirks for the same.
>>>
>>> Signed-off-by: Shah Nehal-Bakulchandra <Nehal-bakulchandra.Shah@xxxxxxx>
>>
>> This is V2 of this patch. In future, please put the version number in the
>> subject and describe the changes since the previous version in a cover email
>> or after the "---" below.
>>
>>> ---
>>> drivers/mmc/core/mmc.c | 6 +--
>>> drivers/mmc/host/sdhci-acpi.c | 89 +++++++++++++++++++++++++++++++++++++++++++
>>> drivers/mmc/host/sdhci.c | 3 +-
>>> drivers/mmc/host/sdhci.h | 5 +++
>>> include/linux/mmc/host.h | 6 +++
>>> 5 files changed, 105 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/drivers/mmc/core/mmc.c b/drivers/mmc/core/mmc.c
>>> index 4ffea14..7bf3736 100644
>>> --- a/drivers/mmc/core/mmc.c
>>> +++ b/drivers/mmc/core/mmc.c
>>> @@ -1164,7 +1164,7 @@ static int mmc_select_hs400(struct mmc_card *card)
>>>
>>> /* Set host controller to HS timing */
>>> mmc_set_timing(card->host, MMC_TIMING_MMC_HS);
>>> -
>>> + host->ios.transition = HS200_TO_HS_TO_HS400;
>>> /* Reduce frequency to HS frequency */
>>> max_dtr = card->ext_csd.hs_max_dtr;
>>> mmc_set_clock(host, max_dtr);
>>> @@ -1196,7 +1196,7 @@ static int mmc_select_hs400(struct mmc_card *card)
>>> mmc_hostname(host), err);
>>> return err;
>>> }
>>> -
>>> + host->ios.transition = SWITCHING_TO_HS400;
>>> /* Set host controller to HS400 timing and frequency */
>>> mmc_set_timing(host, MMC_TIMING_MMC_HS400);
>>> mmc_set_bus_speed(card);
>>> @@ -1204,7 +1204,7 @@ static int mmc_select_hs400(struct mmc_card *card)
>>> err = mmc_switch_status(card);
>>> if (err)
>>> goto out_err;
>>> -
>>> + host->ios.transition = SWITCHED_TO_HS400;
>>> return 0;
>>>
>>> out_err:
>>> diff --git a/drivers/mmc/host/sdhci-acpi.c b/drivers/mmc/host/sdhci-acpi.c
>>> index ac678e9..a3456be 100644
>>> --- a/drivers/mmc/host/sdhci-acpi.c
>>> +++ b/drivers/mmc/host/sdhci-acpi.c
>>> @@ -89,6 +89,47 @@ static inline bool sdhci_acpi_flag(struct sdhci_acpi_host *c, unsigned int flag)
>>> return c->slot && (c->slot->flags & flag);
>>> }
>>>
>>> + /*AMD Driver Strength function*/
>>
>> This comment is redundant - please omit it.
>>
>>> +
>>> +static int amd_select_drive_strength(struct mmc_card *card,
>>> + unsigned int max_dtr, int host_drv,
>>> + int card_drv, int *drv_type)
>>> +{
>>> + return MMC_SET_DRIVER_TYPE_A;
>>> +}
>>> +
>>> +static void sdhci_acpi_amd_hs400_dll(struct sdhci_host *host)
>>> +{
>>> + /*AMD Platform requires dll setting*/
>>> + sdhci_writel(host, 0x40003210, SDHCI_AMD_REST_DLL_REGISTER);
>>> + usleep_range(10, 20);
>>> + sdhci_writel(host, 0x40033210, SDHCI_AMD_REST_DLL_REGISTER);
>>> +}
>>> +
>>> +/*
>>> + * For AMD Platform it is required to disable the tuning
>>> + * bit first controller to bring to HS Mode from HS200
>>> + * mode, later enable to tune to HS400 mode.
>>> + */
>>> +
>>
>> Why can't you hook ->set_ios() e.g.
>>
>> host->mmc_host_ops.set_ios = amd_set_ios;
>>
>> static void amd_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
>> {
>> sdhci_set_ios(mmc, ios);
>>
>> if (ios->timing == MMC_TIMING_MMC_HS400) {
>> sdhci_writew(host, 0x80, SDHCI_HOST_CONTROL2);
>> sdhci_acpi_amd_hs400_dll(host);
>> }
>> }
>>
>>
>>> +static void sdhci_amd_set_hs400_transition(struct sdhci_host *host)
>>> +{
>>> + switch (host->mmc->ios.transition) {
>>> + case HS200_TO_HS_TO_HS400:
>>> + sdhci_writew(host, 0x9, SDHCI_HOST_CONTROL2);
>>
>> Maybe better to just change the bits in SDHCI_HOST_CONTROL2 that you need
>> and leave the other bits alone.
>>
>> We know when we do tuning whether it is for HS400, so maybe you could hook
>> ->execute_tuning() for this e.g.
>>
>> host->mmc_host_ops.execute_tuning = amd_execute_tuning;
>>
>> static int amd_execute_tuning(struct mmc_host *mmc, u32 opcode)
>> {
>> bool hs400_tuning = host->flags & SDHCI_HS400_TUNING;
>> int err;
>>
>> err = sdhci_execute_tuning(mmc, opcode);
>> if (err)
>> return err;
>>
>> /* Disable tuning during switch to HS400 */
>> if (hs400_tuning)
>> sdhci_writew(host, 0x9, SDHCI_HOST_CONTROL2);
>> }
>>
>>> + break;
>>> +
>>> + case SWITCHING_TO_HS400:
>>
>> This case is always ios->timing == MMC_TIMING_MMC_HS400 so you don't need
>> the ios.transition for this
>>
>>> + sdhci_writew(host, 0x80, SDHCI_HOST_CONTROL2);
>>
>> Maybe better to just change the bits in SDHCI_HOST_CONTROL2 that you need
>> and leave the other bits alone.
>>
>>> + sdhci_acpi_amd_hs400_dll(host);
>>> + break;
>>> +
>>> + case SWITCHED_TO_HS400:
>>> + default:
>>> + break;
>>> + }
>>> +}
>>> +
> Liked your suggestions and tried but doesn't work.Because The changes are required in transition phase i.e in case of switching to HS400 just after "mmc_set_timing(card->host, MMC_TIMING_MMC_HS)" call so these changes are intermediate as we have issue with the IP. Now Hooking with execute_tuning makes the functionality non working as execute_tuning gets called before. So is there any better way to handle intermediate transition? Can you please suggest. So instead of using execute_tuning hook up can be done in set_ios however still it requires the transition cases. Something like this
But what about below:
>
> static void amd_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
> {
> struct sdhci_host *host = mmc_priv(mmc);
unsigned old_timing = host->timing;
> sdhci_set_ios(mmc, ios);
>
>
> switch (host->mmc->ios.transition) {
> case HS200_TO_HS_TO_HS400:
if (old_timing == MMC_TIMING_MMC_HS200 &&
ios->timing == MMC_TIMING_SD_HS)
If you want to know if this is the HS400 case, you could record whether the
SDHCI_HS400_TUNING flag was set during tuning.
> {
> printk(KERN_ERR "Sandeep transition HS200 to HS to HS400 \n");
> sdhci_writew(host, 0x9, SDHCI_HOST_CONTROL2);
> }
> break;
>
> case SWITCHING_TO_HS400:
if (old_timing != MMC_TIMING_MMC_HS400 &&
ios->timing == MMC_TIMING_MMC_HS400)
> {
>
> printk(KERN_ERR "Sandeep transition Switching to HS400 \n");
> sdhci_writew(host, 0x80, SDHCI_HOST_CONTROL2);
>
> sdhci_acpi_amd_hs400_dll(host);
> }
> break;
>
> case SWITCHED_TO_HS400:
> default:
> break;
> }
>
> }
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