Re: [PATCH v11 3/7] clk: meson: g12a: make VCLK2 and ENCL clock path configurable by CCF

From: Jerome Brunet
Date: Fri Mar 29 2024 - 09:51:59 EST

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In reply to: Neil Armstrong: "[PATCH v11 3/7] clk: meson: g12a: make VCLK2 and ENCL clock path configurable by CCF"
Next in thread: Neil Armstrong: "Re: [PATCH v11 3/7] clk: meson: g12a: make VCLK2 and ENCL clock path configurable by CCF"
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On Mon 25 Mar 2024 at 12:09, Neil Armstrong <neil.armstrong@xxxxxxxxxx> wrote:

> In order to setup the DSI clock, let's make the unused VCLK2 clock path
> configuration via CCF.
>
> The nocache option is removed from following clocks:
> - vclk2_sel
> - vclk2_input
> - vclk2_div
> - vclk2
> - vclk_div1
> - vclk2_div2_en
> - vclk2_div4_en
> - vclk2_div6_en
> - vclk2_div12_en
> - vclk2_div2
> - vclk2_div4
> - vclk2_div6
> - vclk2_div12
> - cts_encl_sel
>
> vclk2 and vclk2_div uses the newly introduced vclk regmap driver
> to handle the enable and reset bits.
>
> In order to set a rate on cts_encl via the vclk2 clock path,
> the NO_REPARENT flag is set on cts_encl_sel & vclk2_sel in order
> to keep CCF from selection a parent.
> The parents of cts_encl_sel & vclk2_sel are expected to be defined
> in DT or manually set by the display driver at some point.
>
> The following clock scheme is to be used for DSI:
>
> xtal
> \_ gp0_pll_dco
> \_ gp0_pll
> |- vclk2_sel
> | \_ vclk2_input
> | \_ vclk2_div
> | \_ vclk2
> | \_ vclk2_div1
> | \_ cts_encl_sel
> | \_ cts_encl -> to VPU LCD Encoder
> |- mipi_dsi_pxclk_sel
> \_ mipi_dsi_pxclk_div
> \_ mipi_dsi_pxclk -> to DSI controller
>
> The mipi_dsi_pxclk_div is set as bypass with a single /1 entry in div_table
> in order to use the same GP0 for mipi_dsi_pxclk and vclk2_input.
>
> The SET_RATE_PARENT is only set on the mipi_dsi_pxclk_sel clock so the
> DSI bitclock is the reference base clock to calculate the vclk2_div value
> when pixel clock is set on the cts_encl endpoint.
>
> Signed-off-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>
> ---
> drivers/clk/meson/Kconfig | 1 +
> drivers/clk/meson/g12a.c | 72 ++++++++++++++++++++++++++++++++++-------------
> 2 files changed, 53 insertions(+), 20 deletions(-)
>
> diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
> index 8a9823789fa3..59a40a49f8e1 100644
> --- a/drivers/clk/meson/Kconfig
> +++ b/drivers/clk/meson/Kconfig
> @@ -144,6 +144,7 @@ config COMMON_CLK_G12A
> select COMMON_CLK_MESON_EE_CLKC
> select COMMON_CLK_MESON_CPU_DYNDIV
> select COMMON_CLK_MESON_VID_PLL_DIV
> + select COMMON_CLK_MESON_VCLK
> select MFD_SYSCON
> help
> Support for the clock controller on Amlogic S905D2, S905X2 and S905Y2
> diff --git a/drivers/clk/meson/g12a.c b/drivers/clk/meson/g12a.c
> index 90f4c6103014..083882e53b65 100644
> --- a/drivers/clk/meson/g12a.c
> +++ b/drivers/clk/meson/g12a.c
> @@ -22,6 +22,7 @@
> #include "clk-regmap.h"
> #include "clk-cpu-dyndiv.h"
> #include "vid-pll-div.h"
> +#include "vclk.h"
> #include "meson-eeclk.h"
> #include "g12a.h"
>
> @@ -3165,7 +3166,7 @@ static struct clk_regmap g12a_vclk2_sel = {
> .ops = &clk_regmap_mux_ops,
> .parent_hws = g12a_vclk_parent_hws,
> .num_parents = ARRAY_SIZE(g12a_vclk_parent_hws),
> - .flags = CLK_SET_RATE_NO_REPARENT | CLK_GET_RATE_NOCACHE,
> + .flags = CLK_SET_RATE_NO_REPARENT,
> },
> };
>
> @@ -3193,7 +3194,6 @@ static struct clk_regmap g12a_vclk2_input = {
> .ops = &clk_regmap_gate_ops,
> .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2_sel.hw },
> .num_parents = 1,
> - .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED,
> },
> };
>
> @@ -3215,19 +3215,32 @@ static struct clk_regmap g12a_vclk_div = {
> };
>
> static struct clk_regmap g12a_vclk2_div = {
> - .data = &(struct clk_regmap_div_data){
> - .offset = HHI_VIID_CLK_DIV,
> - .shift = 0,
> - .width = 8,
> + .data = &(struct meson_vclk_div_data){
> + .div = {
> + .reg_off = HHI_VIID_CLK_DIV,
> + .shift = 0,
> + .width = 8,
> + },
> + .enable = {
> + .reg_off = HHI_VIID_CLK_DIV,
> + .shift = 16,
> + .width = 1,
> + },
> + .reset = {
> + .reg_off = HHI_VIID_CLK_DIV,
> + .shift = 17,
> + .width = 1,
> + },
> + .flags = CLK_DIVIDER_ROUND_CLOSEST,
> },
> .hw.init = &(struct clk_init_data){
> .name = "vclk2_div",
> - .ops = &clk_regmap_divider_ops,
> + .ops = &meson_vclk_div_ops,
> .parent_hws = (const struct clk_hw *[]) {
> &g12a_vclk2_input.hw
> },
> .num_parents = 1,
> - .flags = CLK_GET_RATE_NOCACHE,
> + .flags = CLK_SET_RATE_GATE,
> },
> };
>
> @@ -3246,16 +3259,24 @@ static struct clk_regmap g12a_vclk = {
> };
>
> static struct clk_regmap g12a_vclk2 = {
> - .data = &(struct clk_regmap_gate_data){
> - .offset = HHI_VIID_CLK_CNTL,
> - .bit_idx = 19,
> + .data = &(struct meson_vclk_gate_data){
> + .enable = {
> + .reg_off = HHI_VIID_CLK_CNTL,
> + .shift = 19,
> + .width = 1,
> + },
> + .reset = {
> + .reg_off = HHI_VIID_CLK_CNTL,
> + .shift = 15,
> + .width = 1,
> + },
> },
> .hw.init = &(struct clk_init_data) {
> .name = "vclk2",
> - .ops = &clk_regmap_gate_ops,
> + .ops = &meson_vclk_gate_ops,
> .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2_div.hw },
> .num_parents = 1,
> - .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED,
> + .flags = CLK_SET_RATE_PARENT,
> },
> };
>
> @@ -3339,7 +3360,7 @@ static struct clk_regmap g12a_vclk2_div1 = {
> .ops = &clk_regmap_gate_ops,
> .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw },
> .num_parents = 1,
> - .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED,
> + .flags = CLK_SET_RATE_PARENT,
> },
> };
>
> @@ -3353,7 +3374,7 @@ static struct clk_regmap g12a_vclk2_div2_en = {
> .ops = &clk_regmap_gate_ops,
> .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw },
> .num_parents = 1,
> - .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED,
> + .flags = CLK_SET_RATE_PARENT,
> },
> };
>
> @@ -3367,7 +3388,7 @@ static struct clk_regmap g12a_vclk2_div4_en = {
> .ops = &clk_regmap_gate_ops,
> .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw },
> .num_parents = 1,
> - .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED,
> + .flags = CLK_SET_RATE_PARENT,
> },
> };
>
> @@ -3381,7 +3402,7 @@ static struct clk_regmap g12a_vclk2_div6_en = {
> .ops = &clk_regmap_gate_ops,
> .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw },
> .num_parents = 1,
> - .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED,
> + .flags = CLK_SET_RATE_PARENT,
> },
> };
>
> @@ -3395,7 +3416,7 @@ static struct clk_regmap g12a_vclk2_div12_en = {
> .ops = &clk_regmap_gate_ops,
> .parent_hws = (const struct clk_hw *[]) { &g12a_vclk2.hw },
> .num_parents = 1,
> - .flags = CLK_SET_RATE_PARENT | CLK_IGNORE_UNUSED,
> + .flags = CLK_SET_RATE_PARENT,
> },
> };
>
> @@ -3461,6 +3482,7 @@ static struct clk_fixed_factor g12a_vclk2_div2 = {
> &g12a_vclk2_div2_en.hw
> },
> .num_parents = 1,
> + .flags = CLK_SET_RATE_PARENT,
> },
> };
>
> @@ -3474,6 +3496,7 @@ static struct clk_fixed_factor g12a_vclk2_div4 = {
> &g12a_vclk2_div4_en.hw
> },
> .num_parents = 1,
> + .flags = CLK_SET_RATE_PARENT,
> },
> };
>
> @@ -3487,6 +3510,7 @@ static struct clk_fixed_factor g12a_vclk2_div6 = {
> &g12a_vclk2_div6_en.hw
> },
> .num_parents = 1,
> + .flags = CLK_SET_RATE_PARENT,
> },
> };
>
> @@ -3500,6 +3524,7 @@ static struct clk_fixed_factor g12a_vclk2_div12 = {
> &g12a_vclk2_div12_en.hw
> },
> .num_parents = 1,
> + .flags = CLK_SET_RATE_PARENT,
> },
> };
>
> @@ -3561,7 +3586,7 @@ static struct clk_regmap g12a_cts_encl_sel = {
> .ops = &clk_regmap_mux_ops,
> .parent_hws = g12a_cts_parent_hws,
> .num_parents = ARRAY_SIZE(g12a_cts_parent_hws),
> - .flags = CLK_SET_RATE_NO_REPARENT | CLK_GET_RATE_NOCACHE,
> + .flags = CLK_SET_RATE_PARENT | CLK_SET_RATE_NO_REPARENT,
> },
> };
>
> @@ -3717,15 +3742,22 @@ static struct clk_regmap g12a_mipi_dsi_pxclk_sel = {
> .ops = &clk_regmap_mux_ops,
> .parent_hws = g12a_mipi_dsi_pxclk_parent_hws,
> .num_parents = ARRAY_SIZE(g12a_mipi_dsi_pxclk_parent_hws),
> - .flags = CLK_SET_RATE_NO_REPARENT,
> + .flags = CLK_SET_RATE_NO_REPARENT | CLK_SET_RATE_PARENT,
> },
> };
>
> +/* Force as bypass by forcing a single /1 table entry, and not rely of boot value */

The comment here is not entirely accurate.

The table below will actually force to only use a 1 divider on
set_rate(), not on boot, AFAICT.

The boot value will stay in the register until the first call to set_rate().

Considering this is quite fragile as it is, It would be nice to prefix
the updated comment with "FIXME"

> +static const struct clk_div_table g12a_mipi_dsi_pxclk_div_table[] = {
> + { .val = 0, .div = 1 },
> + { /* sentinel */ },
> +};
> +
> static struct clk_regmap g12a_mipi_dsi_pxclk_div = {
> .data = &(struct clk_regmap_div_data){
> .offset = HHI_MIPIDSI_PHY_CLK_CNTL,
> .shift = 0,
> .width = 7,
> + .table = g12a_mipi_dsi_pxclk_div_table,
> },
> .hw.init = &(struct clk_init_data){
> .name = "mipi_dsi_pxclk_div",

--
Jerome

Next message: Sasha Levin: "[PATCH AUTOSEL 6.8 80/98] btrfs: preallocate temporary extent buffer for inode logging when needed"
Previous message: Sasha Levin: "[PATCH AUTOSEL 6.8 77/98] input/touchscreen: imagis: Add support for Imagis IST3038B"
In reply to: Neil Armstrong: "[PATCH v11 3/7] clk: meson: g12a: make VCLK2 and ENCL clock path configurable by CCF"
Next in thread: Neil Armstrong: "Re: [PATCH v11 3/7] clk: meson: g12a: make VCLK2 and ENCL clock path configurable by CCF"
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