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

Manivannan Sadhasivam
2023-11-28T06:47:42Z

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?

> + 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.

> + *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().

Rest LGTM.

- Mani

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