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

[claudiu beznea <claudiu.beznea@tuxon.dev>]

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.