Re: [PATCH] clk: meson-axg: add clocks required by pcie driver

From: Yixun Lan
Date: Mon Jun 25 2018 - 09:59:27 EST

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In reply to: Jerome Brunet: "Re: [PATCH] clk: meson-axg: add clocks required by pcie driver"
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Hi Jerome

see my comments below

On 06/25/2018 05:32 PM, Jerome Brunet wrote:
> On Thu, 2018-06-21 at 12:26 +0000, Yixun Lan wrote:
>> Adding clocks for pcie driver, due to the ASIC design,
> Adding clocks for the pcie driver. Due to the ASIC design,
>
Ok, I will adjust these in v2

>> the pcie controller re-use part of the mipi clock logic,
>> so the mipi clock is also required.
>>
>> Tested-by: Jianxin Qin <jianxin.qin@xxxxxxxxxxx>
>> Signed-off-by: Yixun Lan <yixun.lan@xxxxxxxxxxx>
>> ---
>> drivers/clk/meson/axg.c | 145 +++++++++++++++++++++++++++
>> drivers/clk/meson/axg.h | 6 +-
>> include/dt-bindings/clock/axg-clkc.h | 3 +
>> 3 files changed, 153 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/clk/meson/axg.c b/drivers/clk/meson/axg.c
>> index bd4dbc696b88..f1dc5433b69d 100644
>> --- a/drivers/clk/meson/axg.c
>> +++ b/drivers/clk/meson/axg.c
>> @@ -626,6 +626,137 @@ static struct clk_regmap axg_mpll3 = {
>> },
>> };
>>
>> +static const struct pll_rate_table axg_pcie_pll_rate_table[] = {
>> + {
>> + .rate = 100000000,
>> + .m = 200,
>> + .n = 3,
>> + .od = 1,
>> + .od2 = 3,
>> + },
>> + { /* sentinel */ },
>> +};
>> +
>> +static const struct reg_sequence axg_pcie_init_regs[] = {
>> + { .reg = HHI_PCIE_PLL_CNTL, .def = 0x400106c8 },
>> + { .reg = HHI_PCIE_PLL_CNTL1, .def = 0x0084a2aa },
>> + { .reg = HHI_PCIE_PLL_CNTL2, .def = 0xb75020be },
>> + { .reg = HHI_PCIE_PLL_CNTL3, .def = 0x0a47488e },
>> + { .reg = HHI_PCIE_PLL_CNTL4, .def = 0xc000004d },
>> + { .reg = HHI_PCIE_PLL_CNTL5, .def = 0x00078000 },
>> + { .reg = HHI_PCIE_PLL_CNTL6, .def = 0x002323c6 },
>> +};
>> +
>> +static struct clk_regmap axg_pcie_pll = {
>> + .data = &(struct meson_clk_pll_data){
>> + .m = {
>> + .reg_off = HHI_PCIE_PLL_CNTL,
>> + .shift = 0,
>> + .width = 9,
>> + },
>> + .n = {
>> + .reg_off = HHI_PCIE_PLL_CNTL,
>> + .shift = 9,
>> + .width = 5,
>> + },
>> + .od = {
>> + .reg_off = HHI_PCIE_PLL_CNTL,
>> + .shift = 16,
>> + .width = 2,
>> + },
>> + .od2 = {
>> + .reg_off = HHI_PCIE_PLL_CNTL6,
>> + .shift = 6,
>> + .width = 2,
>> + },
>> + .frac = {
>> + .reg_off = HHI_PCIE_PLL_CNTL1,
>> + .shift = 0,
>> + .width = 12,
>> + },
>> + .l = {
>> + .reg_off = HHI_PCIE_PLL_CNTL,
>> + .shift = 31,
>> + .width = 1,
>> + },
>> + .rst = {
>> + .reg_off = HHI_PCIE_PLL_CNTL,
>> + .shift = 29,
>> + .width = 1,
>> + },
>> + .table = axg_pcie_pll_rate_table,
>> + .init_regs = axg_pcie_init_regs,
>> + .init_count = ARRAY_SIZE(axg_pcie_init_regs),
>> + },
>> + .hw.init = &(struct clk_init_data){
>> + .name = "pcie_pll",
>> + .ops = &meson_clk_pll_ops,
>> + .parent_names = (const char *[]){ "xtal" },
>> + .num_parents = 1,
>> + },
>> +};
>> +
>> +static struct clk_regmap axg_pcie_mux = {
>> + .data = &(struct clk_regmap_mux_data){
>> + .offset = HHI_PCIE_PLL_CNTL6,
>> + .mask = 0x1,
>> + .shift = 2,
>> + },
>> + .hw.init = &(struct clk_init_data){
>> + .name = "pcie_mux",
>> + .ops = &clk_regmap_mux_ops,
>> + .parent_names = (const char *[]){ "mpll3", "pcie_pll" },
>> + .num_parents = 2,
>> + .flags = CLK_SET_RATE_PARENT,
>> + },
>> +};
>> +
>> +static struct clk_regmap axg_pcie_ref = {
>> + .data = &(struct clk_regmap_mux_data){
>> + .offset = HHI_PCIE_PLL_CNTL6,
>> + .mask = 0x1,
>> + .shift = 1,
>> + },
>> + .hw.init = &(struct clk_init_data){
>> + .name = "pcie_ref",
>> + .ops = &clk_regmap_mux_ops,
>> + /* do not select the first partent, debug only */
>> + .parent_names = (const char *[]){ "",
>> + "pcie_mux" },
>
> A) No declaring a clock name "" is not the way to do it.
>
> Either declare a mux with just one parent and provide a table with the index of
> the said parent (have a look around, other clocks mux are using table), OR just
> declare what parent 0 is.
>
Ok, in this case, I will go as the first way - using table with only one
parent

the parent 0 is a debug clock which should been feed directly from
outside (via crystal or somthing), and in the normal cases we don't do this.

> Looking at your clock, the pcie driver will have to call
> clk_set_rate(clk, 100000000) to make sure everything is setup properly,
> including this mux - otherwise you are relying on the setting provided by the
> bootloader, which should be avoided whenever possible.
>
yes, we will call clk_set_rate(clk, 100000000), and let CCF propagate
upside.. we definitely want to avoid relying on bootloader to setup this
clock.

> In this case, CCF should pick the right parent anyway, so there should be no
> harm describing what your clock tree is.
if we want to describe debug clock (the parent 0), which I think the
debug clock should be also 100MHz, then it will be equal to parent 1,
then no difference between these two clocks, the pcie driver may wrongly
choose the parent 0 which doesn't exist in the real case if let CCF
choose freely.

to fix this, one solution come to my mind that is to manually select
parent of the mux clock - but it's kind of tedious/un-necessary ..

>
> B) Please fix the indentation.
>
> C) This mux deal with bit "CML_INPUT_SEL0". there is also a "CML_INPUT_SEL1"
> which seems to hint that there is a mux each CML_EN clock. Are you sure your
> description of the tree is accurate ?
>
we already describe these two mux, see

"CML_INPUT_SEL1" -> bit[2]
static struct clk_regmap axg_pcie_mux

"CML_INPUT_SEL0" -> bit[1]
static struct clk_regmap axg_pcie_ref

the clock map is something like this:

"debug" ->| | -> pcie_cml_en0
xtal -> pcie_pll ->| | pcie_ref ->|
| pcie_mux ->| | -> pcie_cml_en1
|
mpll3 ->|

>> + .num_parents = 2,
>> + .flags = CLK_SET_RATE_PARENT,
>> + },
>> +};
>> +
>> +static struct clk_regmap axg_pcie_cml_en0 = {
>> + .data = &(struct clk_regmap_gate_data){
>> + .offset = HHI_PCIE_PLL_CNTL6,
>> + .bit_idx = 4,
>> + },
>> + .hw.init = &(struct clk_init_data) {
>> + .name = "pcie_cml_en0",
>> + .ops = &clk_regmap_gate_ops,
>> + .parent_names = (const char *[]){ "pcie_ref" },
>> + .num_parents = 1,
>> + .flags = CLK_SET_RATE_PARENT,
>> +
>> + },
>> +};
>> +
>> +static struct clk_regmap axg_pcie_cml_en1 = {
>> + .data = &(struct clk_regmap_gate_data){
>> + .offset = HHI_PCIE_PLL_CNTL6,
>> + .bit_idx = 3,
>> + },
>> + .hw.init = &(struct clk_init_data) {
>> + .name = "pcie_cml_en1",
>> + .ops = &clk_regmap_gate_ops,
>> + .parent_names = (const char *[]){ "pcie_ref" },
>> + .num_parents = 1,
>> + .flags = CLK_SET_RATE_PARENT,
>> + },
>> +};
>> +
>> static u32 mux_table_clk81[] = { 0, 2, 3, 4, 5, 6, 7 };
>> static const char * const clk81_parent_names[] = {
>> "xtal", "fclk_div7", "mpll1", "mpll2", "fclk_div4",
>> @@ -821,6 +952,7 @@ static MESON_GATE(axg_mmc_pclk, HHI_GCLK_MPEG2, 11);
>> static MESON_GATE(axg_vpu_intr, HHI_GCLK_MPEG2, 25);
>> static MESON_GATE(axg_sec_ahb_ahb3_bridge, HHI_GCLK_MPEG2, 26);
>> static MESON_GATE(axg_gic, HHI_GCLK_MPEG2, 30);
>> +static MESON_GATE(axg_mipi_enable, HHI_MIPI_CNTL0, 29);
>>
>> /* Always On (AO) domain gates */
>>
>> @@ -910,6 +1042,13 @@ static struct clk_hw_onecell_data axg_hw_onecell_data = {
>> [CLKID_FCLK_DIV4_DIV] = &axg_fclk_div4_div.hw,
>> [CLKID_FCLK_DIV5_DIV] = &axg_fclk_div5_div.hw,
>> [CLKID_FCLK_DIV7_DIV] = &axg_fclk_div7_div.hw,
>> + [CLKID_PCIE_PLL] = &axg_pcie_pll.hw,
>> + [CLKID_PCIE_MUX] = &axg_pcie_mux.hw,
>> + [CLKID_PCIE_REF] = &axg_pcie_ref.hw,
>> + [CLKID_PCIE_CML_EN0] = &axg_pcie_cml_en0.hw,
>> + [CLKID_PCIE_CML_EN1] = &axg_pcie_cml_en1.hw,
>> + [CLKID_MIPI_ENABLE] = &axg_mipi_enable.hw,
>> +
>> [NR_CLKS] = NULL,
>> },
>> .num = NR_CLKS,
>> @@ -988,6 +1127,12 @@ static struct clk_regmap *const axg_clk_regmaps[] = {
>> &axg_fclk_div4,
>> &axg_fclk_div5,
>> &axg_fclk_div7,
>> + &axg_pcie_pll,
>> + &axg_pcie_mux,
>> + &axg_pcie_ref,
>> + &axg_pcie_cml_en0,
>> + &axg_pcie_cml_en1,
>> + &axg_mipi_enable,
>> };
>>
>> static const struct of_device_id clkc_match_table[] = {
>> diff --git a/drivers/clk/meson/axg.h b/drivers/clk/meson/axg.h
>> index b421df6a7ea0..6e55ebd6c77d 100644
>> --- a/drivers/clk/meson/axg.h
>> +++ b/drivers/clk/meson/axg.h
>> @@ -16,6 +16,7 @@
>> * Register offsets from the data sheet must be multiplied by 4 before
>> * adding them to the base address to get the right value.
>> */
>> +#define HHI_MIPI_CNTL0 0x00
>> #define HHI_GP0_PLL_CNTL 0x40
>> #define HHI_GP0_PLL_CNTL2 0x44
>> #define HHI_GP0_PLL_CNTL3 0x48
>> @@ -127,8 +128,11 @@
>> #define CLKID_FCLK_DIV4_DIV 73
>> #define CLKID_FCLK_DIV5_DIV 74
>> #define CLKID_FCLK_DIV7_DIV 75
>> +#define CLKID_PCIE_PLL 76
>> +#define CLKID_PCIE_MUX 77
>> +#define CLKID_PCIE_REF 78
>>
>> -#define NR_CLKS 76
>> +#define NR_CLKS 82
>>
>> /* include the CLKIDs that have been made part of the DT binding */
>> #include <dt-bindings/clock/axg-clkc.h>
>> diff --git a/include/dt-bindings/clock/axg-clkc.h b/include/dt-bindings/clock/axg-clkc.h
>> index 555937a25504..70371228b7e0 100644
>> --- a/include/dt-bindings/clock/axg-clkc.h
>> +++ b/include/dt-bindings/clock/axg-clkc.h
>
> As usual, please put dt bindings changes in a separate patch.
>
ok, will do

>> @@ -68,5 +68,8 @@
>> #define CLKID_SD_EMMC_B_CLK0 59
>> #define CLKID_SD_EMMC_C_CLK0 60
>> #define CLKID_HIFI_PLL 69
>> +#define CLKID_PCIE_CML_EN0 79
>> +#define CLKID_PCIE_CML_EN1 80
>> +#define CLKID_MIPI_ENABLE 81
>>
>> #endif /* __AXG_CLKC_H */
>
> .
>

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Previous message: kbuild test robot: "Re: [PATCH v2 1/2] arm64/mm: Introduce init_pg_dir"
In reply to: Jerome Brunet: "Re: [PATCH] clk: meson-axg: add clocks required by pcie driver"
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