Re: [PATCH v4 27/39] clk: at91: sam9x7: add sam9x7 pmc driver

Varshini.Rajendran
2024-03-18T09:26:32Z

Hi Claudiu,

On 11/03/24 11:28 am, claudiu beznea wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> On 23.02.2024 19:28, Varshini Rajendran wrote:
>> Add a driver for the PMC clocks of sam9x7 Soc family.
>>
>> Signed-off-by: Varshini Rajendran <varshini.rajendran@microchip.com>
>> ---
>> Changes in v4:
>> - Changed variable name alloc_mem to clk_mux_buffer to be more
>> suggestive
>> - Changed description of @f structure member appropriately
>> ---
>> drivers/clk/at91/Makefile | 1 +
>> drivers/clk/at91/sam9x7.c | 946 ++++++++++++++++++++++++++++++++++++++
>> 2 files changed, 947 insertions(+)
>> create mode 100644 drivers/clk/at91/sam9x7.c
>>
>> diff --git a/drivers/clk/at91/Makefile b/drivers/clk/at91/Makefile
>> index 89061b85e7d2..8e3684ba2c74 100644
>> --- a/drivers/clk/at91/Makefile
>> +++ b/drivers/clk/at91/Makefile
>> @@ -20,6 +20,7 @@ obj-$(CONFIG_SOC_AT91SAM9) += at91sam9260.o at91sam9rl.o at91sam9x5.o dt-compat.
>> obj-$(CONFIG_SOC_AT91SAM9) += at91sam9g45.o dt-compat.o
>> obj-$(CONFIG_SOC_AT91SAM9) += at91sam9n12.o at91sam9x5.o dt-compat.o
>> obj-$(CONFIG_SOC_SAM9X60) += sam9x60.o
>> +obj-$(CONFIG_SOC_SAM9X7) += sam9x7.o
>> obj-$(CONFIG_SOC_SAMA5D3) += sama5d3.o dt-compat.o
>> obj-$(CONFIG_SOC_SAMA5D4) += sama5d4.o dt-compat.o
>> obj-$(CONFIG_SOC_SAMA5D2) += sama5d2.o dt-compat.o
>> diff --git a/drivers/clk/at91/sam9x7.c b/drivers/clk/at91/sam9x7.c
>> new file mode 100644
>> index 000000000000..d03387d2e35a
>> --- /dev/null
>> +++ b/drivers/clk/at91/sam9x7.c
>> @@ -0,0 +1,946 @@
>> +// SPDX-License-Identifier: GPL-2.0
>> +/*
>> + * SAM9X7 PMC code.
>> + *
>> + * Copyright (C) 2023 Microchip Technology Inc. and its subsidiaries
>> + *
>> + * Author: Varshini Rajendran <varshini.rajendran@microchip.com>
>> + *
>> + */
>> +#include <linux/clk.h>
>> +#include <linux/clk-provider.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/slab.h>
>> +
>> +#include <dt-bindings/clock/at91.h>
>> +
>> +#include "pmc.h"
>> +
>> +static DEFINE_SPINLOCK(pmc_pll_lock);
>> +static DEFINE_SPINLOCK(mck_lock);
>> +
>> +/**
>> + * enum pll_ids - PLL clocks identifiers
>> + * @PLL_ID_PLLA: PLLA identifier
>> + * @PLL_ID_UPLL: UPLL identifier
>> + * @PLL_ID_AUDIO: Audio PLL identifier
>> + * @PLL_ID_LVDS: LVDS PLL identifier
>> + * @PLL_ID_PLLA_DIV2: PLLA DIV2 identifier
>> + * @PLL_ID_MAX: Max PLL Identifier
>> + */
>> +enum pll_ids {
>> + PLL_ID_PLLA,
>> + PLL_ID_UPLL,
>> + PLL_ID_AUDIO,
>> + PLL_ID_LVDS,
>> + PLL_ID_PLLA_DIV2,
>> + PLL_ID_MAX,
>> +};
>> +
>> +/**
>> + * enum pll_type - PLL type identifiers
>> + * @PLL_TYPE_FRAC: fractional PLL identifier
>> + * @PLL_TYPE_DIV: divider PLL identifier
>> + */
>> +enum pll_type {
>> + PLL_TYPE_FRAC,
>> + PLL_TYPE_DIV,
>> +};
>> +
>> +static const struct clk_master_characteristics mck_characteristics = {
>> + .output = { .min = 32000000, .max = 266666667 },
>> + .divisors = { 1, 2, 4, 3, 5},
>> + .have_div3_pres = 1,
>> +};
>> +
>> +static const struct clk_master_layout sam9x7_master_layout = {
>> + .mask = 0x373,
>> + .pres_shift = 4,
>> + .offset = 0x28,
>> +};
>> +
>> +/* Fractional PLL core output range. */
>> +static const struct clk_range plla_core_outputs[] = {
>> + { .min = 375000000, .max = 1600000000 },
>> +};
>> +
>> +static const struct clk_range upll_core_outputs[] = {
>> + { .min = 600000000, .max = 1200000000 },
>> +};
>> +
>> +static const struct clk_range lvdspll_core_outputs[] = {
>> + { .min = 400000000, .max = 800000000 },
>> +};
>> +
>> +static const struct clk_range audiopll_core_outputs[] = {
>> + { .min = 400000000, .max = 800000000 },
>> +};
>> +
>> +static const struct clk_range plladiv2_core_outputs[] = {
>> + { .min = 375000000, .max = 1600000000 },
>> +};
>> +
>> +/* Fractional PLL output range. */
>> +static const struct clk_range plla_outputs[] = {
>> + { .min = 732421, .max = 800000000 },
>> +};
>> +
>> +static const struct clk_range upll_outputs[] = {
>> + { .min = 300000000, .max = 600000000 },
>> +};
>> +
>> +static const struct clk_range lvdspll_outputs[] = {
>> + { .min = 10000000, .max = 800000000 },
>> +};
>> +
>> +static const struct clk_range audiopll_outputs[] = {
>> + { .min = 10000000, .max = 800000000 },
>> +};
>> +
>> +static const struct clk_range plladiv2_outputs[] = {
>> + { .min = 366210, .max = 400000000 },
>> +};
>> +
>> +/* PLL characteristics. */
>> +static const struct clk_pll_characteristics plla_characteristics = {
>> + .input = { .min = 20000000, .max = 50000000 },
>> + .num_output = ARRAY_SIZE(plla_outputs),
>> + .output = plla_outputs,
>> + .core_output = plla_core_outputs,
>> +};
>> +
>> +static const struct clk_pll_characteristics upll_characteristics = {
>> + .input = { .min = 20000000, .max = 50000000 },
>> + .num_output = ARRAY_SIZE(upll_outputs),
>> + .output = upll_outputs,
>> + .core_output = upll_core_outputs,
>> + .upll = true,
>> +};
>> +
>> +static const struct clk_pll_characteristics lvdspll_characteristics = {
>> + .input = { .min = 20000000, .max = 50000000 },
>> + .num_output = ARRAY_SIZE(lvdspll_outputs),
>> + .output = lvdspll_outputs,
>> + .core_output = lvdspll_core_outputs,
>> +};
>> +
>> +static const struct clk_pll_characteristics audiopll_characteristics = {
>> + .input = { .min = 20000000, .max = 50000000 },
>> + .num_output = ARRAY_SIZE(audiopll_outputs),
>> + .output = audiopll_outputs,
>> + .core_output = audiopll_core_outputs,
>> +};
>> +
>> +static const struct clk_pll_characteristics plladiv2_characteristics = {
>> + .input = { .min = 20000000, .max = 50000000 },
>> + .num_output = ARRAY_SIZE(plladiv2_outputs),
>> + .output = plladiv2_outputs,
>> + .core_output = plladiv2_core_outputs,
>> +};
>> +
>> +/* Layout for fractional PLL ID PLLA. */
>> +static const struct clk_pll_layout plla_frac_layout = {
>> + .mul_mask = GENMASK(31, 24),
>> + .frac_mask = GENMASK(21, 0),
>> + .mul_shift = 24,
>> + .frac_shift = 0,
>> + .div2 = 1,
>
> It seems to me that this is not taken into account (see below).
>
>> +};
>> +
>> +/* Layout for fractional PLLs. */
>> +static const struct clk_pll_layout pll_frac_layout = {
>> + .mul_mask = GENMASK(31, 24),
>> + .frac_mask = GENMASK(21, 0),
>> + .mul_shift = 24,
>> + .frac_shift = 0,
>> +};
>> +
>> +/* Layout for DIV PLLs. */
>> +static const struct clk_pll_layout pll_divpmc_layout = {
>> + .div_mask = GENMASK(7, 0),
>> + .endiv_mask = BIT(29),
>> + .div_shift = 0,
>> + .endiv_shift = 29,
>> +};
>> +
>> +/* Layout for DIV PLL ID PLLADIV2. */
>> +static const struct clk_pll_layout plladiv2_divpmc_layout = {
>> + .div_mask = GENMASK(7, 0),
>> + .endiv_mask = BIT(29),
>> + .div_shift = 0,
>> + .endiv_shift = 29,
>> + .div2 = 1,
>> +};
>> +
>> +/* Layout for DIVIO dividers. */
>> +static const struct clk_pll_layout pll_divio_layout = {
>> + .div_mask = GENMASK(19, 12),
>> + .endiv_mask = BIT(30),
>> + .div_shift = 12,
>> + .endiv_shift = 30,
>> +};
>> +
>> +/*
>> + * PLL clocks description
>> + * @n: clock name
>> + * @p: clock parent
>> + * @l: clock layout
>> + * @t: clock type
>> + * @c: pll characteristics
>> + * @f: clock flags
>> + * @eid: export index in sam9x7->chws[] array
>> + */
>> +static const struct {
>> + const char *n;
>> + const char *p;
>> + const struct clk_pll_layout *l;
>> + u8 t;
>> + const struct clk_pll_characteristics *c;
>> + unsigned long f;
>> + u8 eid;
>> +} sam9x7_plls[][PLL_ID_MAX] = {
>> + [PLL_ID_PLLA] = {
>> + {
>> + .n = "plla_fracck",
>> + .p = "mainck",
>> + .l = &plla_frac_layout,
>> + .t = PLL_TYPE_FRAC,
>> + /*
>> + * This feeds plla_divpmcck which feeds CPU. It should
>> + * not be disabled.
>> + */
>> + .f = CLK_IS_CRITICAL | CLK_SET_RATE_GATE,
>> + .c = &plla_characteristics,
>> + },
>> +
>> + {
>> + .n = "plla_divpmcck",
>> + .p = "plla_fracck",
>> + .l = &pll_divpmc_layout,
>
> You mentioned in "[PATCH v4 24/39] clk: at91: sam9x7: add support for HW
> PLL freq dividers" that this has div2 but it is registered w/ a layout that
> has .div2 = 0.

This is handled in the above plla_fracck fractional part as defined in
the plla_frac_layout.
>
>

--
Thanks and Regards,
Varshini Rajendran.