Re: [PATCH v5 09/10] phy: qualcomm: phy-qcom-qmp-ufs: Add High Speed Gear 5 support for SM8550

Can Guo
2023-11-28T09:01:14Z

On 11/28/2023 2:47 PM, Manivannan Sadhasivam wrote:
> On Thu, Nov 23, 2023 at 12:46:29AM -0800, Can Guo wrote:
>> On SM8550, two sets of UFS PHY settings are provided, one set is to support
>> HS-G5, another set is to support HS-G4 and lower gears. The two sets of PHY
>> settings are programming different values to different registers, mixing
>> the two sets and/or overwriting one set with another set is definitely not
>> blessed by UFS PHY designers.
>>
>> To add HS-G5 support for SM8550, split the two sets of PHY settings into
>> their dedicated overlay tables, only the common parts of the two sets of
>> PHY settings are left in the .tbls.
>>
>> Consider we are going to add even higher gear support in future, to avoid
>> adding more tables with different names, rename the .tbls_hs_g4 and make it
>> an array, a size of 2 is enough as of now.
>>
>> In this case, .tbls alone is not a complete set of PHY settings, so either
>> tbls_hs_overlay[0] or tbls_hs_overlay[1] must be applied on top of the
>> .tbls to become a complete set of PHY settings.
>>
>
> Thanks for the update! This really helps in minimizing the changes for future
> gears.
>
>> Signed-off-by: Can Guo <quic_cang@quicinc.com>
>> ---
>> drivers/phy/qualcomm/phy-qcom-qmp-pcs-ufs-v6.h | 2 +
>> drivers/phy/qualcomm/phy-qcom-qmp-qserdes-com-v6.h | 2 +
>> .../qualcomm/phy-qcom-qmp-qserdes-txrx-ufs-v6.h | 9 ++
>> drivers/phy/qualcomm/phy-qcom-qmp-ufs.c | 174 ++++++++++++++++++---
>> 4 files changed, 166 insertions(+), 21 deletions(-)
>>
>>
>
> [...]
>
>> -static void qmp_ufs_init_registers(struct qmp_ufs *qmp, const struct qmp_phy_cfg *cfg)
>> +static bool qmp_ufs_match_gear_overlay(struct qmp_ufs *qmp, const struct qmp_phy_cfg *cfg, int *i)
>> +{
>> + u32 max_gear, floor_max_gear = cfg->max_supported_gear;
>> + bool found = false;
>> + int j;
>> +
>> + for (j = 0; j < NUM_OVERLAY; j ++) {
>> + max_gear = cfg->tbls_hs_overlay[j].max_gear;
>> +
>> + if (max_gear == 0)
>
> Is this condition possible for hs_overlay tables?

Yes, now there are 2 overlays for SM8550, but only one overlay for the
rest targets. For those who has only one overlay, this check fits them.

>
>> + continue;
>> +
>> + /* Direct matching, bail */
>> + if (qmp->submode == max_gear) {
>> + *i = j;
>> + return true;
>> + }
>> +
>> + /* If no direct matching, the lowest gear is the best matching */
>> + if (max_gear < floor_max_gear) {
>
> Can you start the loop from max? If looks odd to set the matching params in the
> first iteration itself and then checking the next one.

OK, will start from j = NUM_VERLAY - 1; in next version. When I wrote
the code, I was not expecting the max is always in the last overlay,
they can come in any orders.

>
>> + *i = j;
>> + found = true;
>> + floor_max_gear = max_gear;
>> + }
>> + }
>> +
>> + return found;
>> +}
>> +
>> +static int qmp_ufs_init_registers(struct qmp_ufs *qmp, const struct qmp_phy_cfg *cfg)
>> {
>> + bool apply_overlay;
>> + int i;
>> +
>> + if (qmp->submode > cfg->max_supported_gear || qmp->submode == 0) {
>> + dev_err(qmp->dev, "Invalid PHY submode %u\n", qmp->submode);
>> + return -EINVAL;
>> + }
>
> This check should be moved to qmp_ufs_set_mode().

OK.

Thanks,
Can Guo.

>
> Rest LGTM.
>
> - Mani
>