Re: [PATCH v2 1/2] drm/msm/dsi: Use "ref" fw clock instead of global name for VCO parent

[AngeloGioacchino Del Regno]

Il 30/08/21 20:24, Marijn Suijten ha scritto:
> All DSI PHY/PLL drivers were referencing their VCO parent clock by a
> global name, most of which don't exist or have been renamed.  These
> clock drivers seem to function fine without that except the 14nm driver
> for the sdm6xx [1].
>
> At the same time all DTs provide a "ref" clock as per the requirements
> of dsi-phy-common.yaml, but the clock is never used.  This patchset puts
> that clock to use without relying on a global clock name, so that all
> dependencies are explicitly defined in DT (the firmware) in the end.
>
> Note that msm8974 is the only board not providing this clock, and
> apq8064 was providing the wrong clock (19.2MHz cxo instead of 27MHz
> pxo).  Both have been been addressed in separate patches that are
> supposed to land well in advance of this patchset.
>
> Furthermore not all board-DTs provided this clock initially but that
> deficiency has been addressed in followup patches (see the Fixes:
> below).  Those commits seem to assume that the clock was used, while
> nothing in history indicates that this "ref" clock was ever retrieved.
>
> [1]: https://lore.kernel.org/linux-arm-msm/386db1a6-a1cd-3c7d-a88e-dc83f8a1be96@xxxxxxxxxxxxxx/
>
> Fixes: 79e51645a1dd ("arm64: dts: qcom: msm8916: Set 'xo_board' as ref clock of the DSI PHY")
> Fixes: 6969d1d9c615 ("ARM: dts: qcom-apq8064: Set 'cxo_board' as ref clock of the DSI PHY")
> Fixes: 0c0e72705a33 ("arm64: dts: sdm845: Set 'bi_tcxo' as ref clock of the DSI PHYs")
> Signed-off-by: Marijn Suijten <marijn.suijten@xxxxxxxxxxxxxx>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxxx>

> ---
>   drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c      | 4 +++-
>   drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c      | 4 +++-
>   drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c      | 4 +++-
>   drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm_8960.c | 4 +++-
>   drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c       | 4 +++-
>   5 files changed, 15 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c
> index e46b10fc793a..3cbb1f1475e8 100644
> --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c
> +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_10nm.c
> @@ -562,7 +562,9 @@ static int pll_10nm_register(struct dsi_pll_10nm *pll_10nm, struct clk_hw **prov
>   	char clk_name[32], parent[32], vco_name[32];
>   	char parent2[32], parent3[32], parent4[32];
>   	struct clk_init_data vco_init = {
> -		.parent_names = (const char *[]){ "xo" },
> +		.parent_data = &(const struct clk_parent_data) {
> +			.fw_name = "ref",
> +		},
>   		.num_parents = 1,
>   		.name = vco_name,
>   		.flags = CLK_IGNORE_UNUSED,
> diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c
> index bb31230721bd..406470265408 100644
> --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c
> +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c
> @@ -804,7 +804,9 @@ static int pll_14nm_register(struct dsi_pll_14nm *pll_14nm, struct clk_hw **prov
>   {
>   	char clk_name[32], parent[32], vco_name[32];
>   	struct clk_init_data vco_init = {
> -		.parent_names = (const char *[]){ "xo" },
> +		.parent_data = &(const struct clk_parent_data) {
> +			.fw_name = "ref",
> +		},
>   		.num_parents = 1,
>   		.name = vco_name,
>   		.flags = CLK_IGNORE_UNUSED,
> diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c
> index 2da673a2add6..8ee9c9c0548d 100644
> --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c
> +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm.c
> @@ -521,7 +521,9 @@ static int pll_28nm_register(struct dsi_pll_28nm *pll_28nm, struct clk_hw **prov
>   {
>   	char clk_name[32], parent1[32], parent2[32], vco_name[32];
>   	struct clk_init_data vco_init = {
> -		.parent_names = (const char *[]){ "xo" },
> +		.parent_data = &(const struct clk_parent_data) {
> +			.fw_name = "ref",
> +		},
>   		.num_parents = 1,
>   		.name = vco_name,
>   		.flags = CLK_IGNORE_UNUSED,
> diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm_8960.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm_8960.c
> index aaa37456f4ee..9662cb236468 100644
> --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm_8960.c
> +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_28nm_8960.c
> @@ -385,7 +385,9 @@ static int pll_28nm_register(struct dsi_pll_28nm *pll_28nm, struct clk_hw **prov
>   {
>   	char *clk_name, *parent_name, *vco_name;
>   	struct clk_init_data vco_init = {
> -		.parent_names = (const char *[]){ "pxo" },
> +		.parent_data = &(const struct clk_parent_data) {
> +			.fw_name = "ref",
> +		},
>   		.num_parents = 1,
>   		.flags = CLK_IGNORE_UNUSED,
>   		.ops = &clk_ops_dsi_pll_28nm_vco,
> diff --git a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c
> index 7c23d4c47338..c77c30628cca 100644
> --- a/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c
> +++ b/drivers/gpu/drm/msm/dsi/phy/dsi_phy_7nm.c
> @@ -590,7 +590,9 @@ static int pll_7nm_register(struct dsi_pll_7nm *pll_7nm, struct clk_hw **provide
>   	char clk_name[32], parent[32], vco_name[32];
>   	char parent2[32], parent3[32], parent4[32];
>   	struct clk_init_data vco_init = {
> -		.parent_names = (const char *[]){ "bi_tcxo" },
> +		.parent_data = &(const struct clk_parent_data) {
> +			.fw_name = "ref",
> +		},
>   		.num_parents = 1,
>   		.name = vco_name,
>   		.flags = CLK_IGNORE_UNUSED,