Re: [PATCH v1 2/2] clk: qcom : dispcc: Add support for display port clocks

[Stephen Boyd]

Quoting Taniya Das (2018-10-09 06:57:47)
> diff --git a/drivers/clk/qcom/dispcc-sdm845.c b/drivers/clk/qcom/dispcc-sdm845.c
> index 0cc4909..6d3136a 100644
> --- a/drivers/clk/qcom/dispcc-sdm845.c
> +++ b/drivers/clk/qcom/dispcc-sdm845.c
> @@ -128,6 +144,100 @@ enum {
>         },
>  };
> 
> +static const struct freq_tbl ftbl_disp_cc_mdss_dp_aux_clk_src[] = {
> +       F(19200000, P_BI_TCXO, 1, 0, 0),
> +       { }
> +};
> +
> +static struct clk_rcg2 disp_cc_mdss_dp_aux_clk_src = {
> +       .cmd_rcgr = 0x219c,
> +       .mnd_width = 0,
> +       .hid_width = 5,
> +       .parent_map = disp_cc_parent_map_2,
> +       .freq_tbl = ftbl_disp_cc_mdss_dp_aux_clk_src,
> +       .clkr.hw.init = &(struct clk_init_data){
> +               .name = "disp_cc_mdss_dp_aux_clk_src",
> +               .parent_names = disp_cc_parent_names_2,
> +               .num_parents = 2,
> +               .flags = CLK_SET_RATE_PARENT,
> +               .ops = &clk_rcg2_ops,
> +       },
> +};
> +
> +static const struct freq_tbl ftbl_disp_cc_mdss_dp_crypto_clk_src[] = {
> +       F(108000, P_DP_PHY_PLL_LINK_CLK,   3,   0,   0),
> +       F(180000, P_DP_PHY_PLL_LINK_CLK,   3,   0,   0),
> +       F(360000, P_DP_PHY_PLL_LINK_CLK,   3,   0,   0),
> +       F(540000, P_DP_PHY_PLL_LINK_CLK,   3,   0,   0),
> +       { }
> +};
> +
> +static struct clk_rcg2 disp_cc_mdss_dp_crypto_clk_src = {
> +       .cmd_rcgr = 0x2154,
> +       .mnd_width = 0,
> +       .hid_width = 5,
> +       .parent_map = disp_cc_parent_map_1,
> +       .freq_tbl = ftbl_disp_cc_mdss_dp_crypto_clk_src,
> +       .clkr.hw.init = &(struct clk_init_data){
> +               .name = "disp_cc_mdss_dp_crypto_clk_src",
> +               .parent_names = disp_cc_parent_names_1,
> +               .num_parents = 4,
> +               .flags = CLK_GET_RATE_NOCACHE,

Why?

> +               .ops = &clk_rcg2_ops,
> +       },
> +};
> +
> +static const struct freq_tbl ftbl_disp_cc_mdss_dp_link_clk_src[] = {
> +       F(162000, P_DP_PHY_PLL_LINK_CLK,   1,   0,   0),
> +       F(270000, P_DP_PHY_PLL_LINK_CLK,   1,   0,   0),
> +       F(540000, P_DP_PHY_PLL_LINK_CLK,   1,   0,   0),
> +       F(810000, P_DP_PHY_PLL_LINK_CLK,   1,   0,   0),

Are these in kHz? They really look like it and that's bad. Why do we
need them at all? Just to make sure the display driver picks these exact
frequencies? It seems like we could just pass whatever number comes in
up to the parent and see what it can do.

> +       { }
> +};
> +
> +static struct clk_rcg2 disp_cc_mdss_dp_link_clk_src = {
> +       .cmd_rcgr = 0x2138,
> +       .mnd_width = 0,
> +       .hid_width = 5,
> +       .parent_map = disp_cc_parent_map_1,
> +       .freq_tbl = ftbl_disp_cc_mdss_dp_link_clk_src,
> +       .clkr.hw.init = &(struct clk_init_data){
> +               .name = "disp_cc_mdss_dp_link_clk_src",
> +               .parent_names = disp_cc_parent_names_1,
> +               .num_parents = 4,
> +               .flags = CLK_SET_RATE_PARENT,
> +               .ops = &clk_rcg2_ops,
> +       },
> +};
> +
> +static struct clk_rcg2 disp_cc_mdss_dp_pixel1_clk_src = {
> +       .cmd_rcgr = 0x2184,
> +       .mnd_width = 16,
> +       .hid_width = 5,
> +       .parent_map = disp_cc_parent_map_1,
> +       .clkr.hw.init = &(struct clk_init_data){
> +               .name = "disp_cc_mdss_dp_pixel1_clk_src",
> +               .parent_names = disp_cc_parent_names_1,
> +               .num_parents = 4,
> +               .flags = CLK_SET_RATE_PARENT,
> +               .ops = &clk_dp_ops,
> +       },
> +};
> +
> +static struct clk_rcg2 disp_cc_mdss_dp_pixel_clk_src = {
> +       .cmd_rcgr = 0x216c,
> +       .mnd_width = 16,
> +       .hid_width = 5,
> +       .parent_map = disp_cc_parent_map_1,
> +       .clkr.hw.init = &(struct clk_init_data){
> +               .name = "disp_cc_mdss_dp_pixel_clk_src",
> +               .parent_names = disp_cc_parent_names_1,
> +               .num_parents = 4,
> +               .flags = CLK_SET_RATE_PARENT,
> +               .ops = &clk_dp_ops,
> +       },
> +};
> +
>  static const struct freq_tbl ftbl_disp_cc_mdss_esc0_clk_src[] = {
>         F(19200000, P_BI_TCXO, 1, 0, 0),
>         { }
> @@ -391,6 +501,115 @@ enum {
>         },
>  };
> 
> +static struct clk_branch disp_cc_mdss_dp_aux_clk = {
> +       .halt_reg = 0x2054,
> +       .halt_check = BRANCH_HALT,
> +       .clkr = {
> +               .enable_reg = 0x2054,
> +               .enable_mask = BIT(0),
> +               .hw.init = &(struct clk_init_data){
> +                       .name = "disp_cc_mdss_dp_aux_clk",
> +                       .parent_names = (const char *[]){
> +                               "disp_cc_mdss_dp_aux_clk_src",
> +                       },
> +                       .num_parents = 1,
> +                       .flags = CLK_SET_RATE_PARENT,
> +                       .ops = &clk_branch2_ops,
> +               },
> +       },
> +};
> +
> +static struct clk_branch disp_cc_mdss_dp_crypto_clk = {
> +       .halt_reg = 0x2048,
> +       .halt_check = BRANCH_HALT,
> +       .clkr = {
> +               .enable_reg = 0x2048,
> +               .enable_mask = BIT(0),
> +               .hw.init = &(struct clk_init_data){
> +                       .name = "disp_cc_mdss_dp_crypto_clk",
> +                       .parent_names = (const char *[]){
> +                               "disp_cc_mdss_dp_crypto_clk_src",
> +                       },
> +                       .num_parents = 1,
> +                       .flags = CLK_SET_RATE_PARENT,
> +                       .ops = &clk_branch2_ops,
> +               },
> +       },
> +};
> +
> +static struct clk_branch disp_cc_mdss_dp_link_clk = {
> +       .halt_reg = 0x2040,
> +       .halt_check = BRANCH_HALT,
> +       .clkr = {
> +               .enable_reg = 0x2040,
> +               .enable_mask = BIT(0),
> +               .hw.init = &(struct clk_init_data){
> +                       .name = "disp_cc_mdss_dp_link_clk",
> +                       .parent_names = (const char *[]){
> +                               "disp_cc_mdss_dp_link_clk_src",
> +                       },
> +                       .num_parents = 1,
> +                       .flags = CLK_SET_RATE_PARENT,
> +                       .ops = &clk_branch2_ops,
> +               },
> +       },
> +};
> +
> +/* reset state of disp_cc_mdss_dp_link_div_clk_src divider is 0x3 (div 4) */

Not sure what this comment is for. But it's interesting nonetheless.

> +static struct clk_branch disp_cc_mdss_dp_link_intf_clk = {
> +       .halt_reg = 0x2044,
> +       .halt_check = BRANCH_HALT,
> +       .clkr = {
> +               .enable_reg = 0x2044,
> +               .enable_mask = BIT(0),
> +               .hw.init = &(struct clk_init_data){
> +                       .name = "disp_cc_mdss_dp_link_intf_clk",
> +                       .parent_names = (const char *[]){
> +                               "disp_cc_mdss_dp_link_clk_src",
> +                       },
> +                       .num_parents = 1,
> +                       .flags = CLK_GET_RATE_NOCACHE,

Why?

> +                       .ops = &clk_branch2_ops,
> +               },
> +       },
> +};
> +