[PATCH v9 2/5] clk: meson: a1: add Amlogic A1 PLL clock controller driver
Jerome Brunet
jbrunet at baylibre.com
Thu Mar 9 06:20:23 PST 2023
On Mon 06 Mar 2023 at 23:05, Dmitry Rokosov <ddrokosov at sberdevices.ru> wrote:
> On Mon, Mar 06, 2023 at 12:17:23PM +0100, Jerome Brunet wrote:
>>
>> On Wed 01 Mar 2023 at 21:37, Dmitry Rokosov <ddrokosov at sberdevices.ru> wrote:
>>
>> > Introduce PLL clock controller for Amlogic A1 SoC family.
>> >
>> > Signed-off-by: Jian Hu <jian.hu at amlogic.com>
>> > Signed-off-by: Dmitry Rokosov <ddrokosov at sberdevices.ru>
>> > ---
>> > drivers/clk/meson/Kconfig | 10 +
>> > drivers/clk/meson/Makefile | 1 +
>> > drivers/clk/meson/a1-pll.c | 365 +++++++++++++++++++++++++++++++++++++
>> > drivers/clk/meson/a1-pll.h | 47 +++++
>> > 4 files changed, 423 insertions(+)
>> > create mode 100644 drivers/clk/meson/a1-pll.c
>> > create mode 100644 drivers/clk/meson/a1-pll.h
>> >
>
> [...]
>
>> > diff --git a/drivers/clk/meson/a1-pll.c b/drivers/clk/meson/a1-pll.c
>> > new file mode 100644
>> > index 000000000000..c565f9b2a8dd
>> > --- /dev/null
>> > +++ b/drivers/clk/meson/a1-pll.c
>> > @@ -0,0 +1,365 @@
>> > +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
>> > +/*
>> > + * Copyright (c) 2019 Amlogic, Inc. All rights reserved.
>> > + * Author: Jian Hu <jian.hu at amlogic.com>
>> > + *
>> > + * Copyright (c) 2023, SberDevices. All Rights Reserved.
>> > + * Author: Dmitry Rokosov <ddrokosov at sberdevices.ru>
>> > + */
>> > +
>> > +#include <linux/clk-provider.h>
>> > +#include <linux/of_device.h>
>> > +#include <linux/platform_device.h>
>> > +#include "meson-a1-clkc.h"
>>
>> As pointed out by the kernel robot, there is a problem here
>>
>
> My fault. Really sorry for that.
>
> [...]
>
>> > +static struct clk_regmap fixed_pll = {
>> > + .data = &(struct clk_regmap_gate_data){
>> > + .offset = ANACTRL_FIXPLL_CTRL0,
>> > + .bit_idx = 20,
>> > + },
>> > + .hw.init = &(struct clk_init_data) {
>> > + .name = "fixed_pll",
>> > + .ops = &clk_regmap_gate_ops,
>> > + .parent_hws = (const struct clk_hw *[]) {
>> > + &fixed_pll_dco.hw
>> > + },
>> > + .num_parents = 1,
>> > + /*
>> > + * It is enough that the fdiv leaf has critical flag,
>> > + * No critical or unused flag here.
>> > + */
>>
>> The comment is not useful
>>
>
> OK
>
>> > + },
>> > +};
>> > +
>> > +static const struct pll_mult_range hifi_pll_mult_range = {
>> > + .min = 32,
>> > + .max = 64,
>> > +};
>> > +
>> > +static const struct reg_sequence hifi_init_regs[] = {
>> > + { .reg = ANACTRL_HIFIPLL_CTRL1, .def = 0x01800000 },
>> > + { .reg = ANACTRL_HIFIPLL_CTRL2, .def = 0x00001100 },
>> > + { .reg = ANACTRL_HIFIPLL_CTRL3, .def = 0x100a1100 },
>> > + { .reg = ANACTRL_HIFIPLL_CTRL4, .def = 0x00302000 },
>> > + { .reg = ANACTRL_HIFIPLL_CTRL0, .def = 0x01f18440 },
>>
>> This last poke should not bits otherwise handled by parms.
>> This is a rate init in disguise.
>>
>
> I believe, you are talking about hifi_pll clk_regmap conflicts with
> hifi_init_regs. The above init sequence shouldn't affect pll regmap setup,
> it doesn't touch them (we assume that default bit values are all zero):
>
> .en = {
> .reg_off = ANACTRL_HIFIPLL_CTRL0,
> .shift = 28,
> .width = 1,
> },
> // init_value = 0x01f18440
> // en_mask = 0x10000000
>
> .m = {
> .reg_off = ANACTRL_HIFIPLL_CTRL0,
> .shift = 0,
> .width = 8,
> },
> // init_value = 0x01f18440
> // m_mask = 0x0000000f
mask is 0xff with width 8
>
> .n = {
> .reg_off = ANACTRL_HIFIPLL_CTRL0,
> .shift = 10,
> .width = 5,
> },
> // init_value = 0x01f18440
> // n_mask = 0x00007c00
> ^
> oops, one overlap
> but why we can't set init value for pre_sel?
>
> .frac = {
> .reg_off = ANACTRL_HIFIPLL_CTRL1,
> .shift = 0,
> .width = 19,
> },
> // init_value = 0x01800000
> // frac_mask = 0x0007ffff
>
> .current_en = {
> .reg_off = ANACTRL_HIFIPLL_CTRL0,
> .shift = 26,
> .width = 1,
> },
> // init_value = 0x01f18440
> // current_en_mask = 0x04000000
>
> .l_detect = {
> .reg_off = ANACTRL_HIFIPLL_CTRL2,
> .shift = 6,
> .width = 1,
> },
> // init_value = 0x00001100
> // l_detect_mask = 0x00000040
>
>> > +};
>> > +
>> > +static struct clk_regmap hifi_pll = {
>> > + .data = &(struct meson_clk_pll_data){
>> > + .en = {
>> > + .reg_off = ANACTRL_HIFIPLL_CTRL0,
>> > + .shift = 28,
>> > + .width = 1,
>> > + },
>> > + .m = {
>> > + .reg_off = ANACTRL_HIFIPLL_CTRL0,
>> > + .shift = 0,
>> > + .width = 8,
>> > + },
>> > + .n = {
>> > + .reg_off = ANACTRL_HIFIPLL_CTRL0,
>> > + .shift = 10,
>> > + .width = 5,
>> > + },
>> > + .frac = {
>> > + .reg_off = ANACTRL_HIFIPLL_CTRL1,
>> > + .shift = 0,
>> > + .width = 19,
>> > + },
>> > + .l = {
>> > + .reg_off = ANACTRL_HIFIPLL_STS,
>> > + .shift = 31,
>> > + .width = 1,
>> > + },
>> > + .current_en = {
>> > + .reg_off = ANACTRL_HIFIPLL_CTRL0,
>> > + .shift = 26,
>> > + .width = 1,
>> > + },
>> > + .l_detect = {
>>
>> What is this ?
>>
>
> Lock detection module.
>
> This is IP module included to new PLL power-on sequence. From clk-pll.c
> patchset:
>
> /*
> * Compared with the previous SoCs, self-adaption current module
> * is newly added for A1, keep the new power-on sequence to enable the
> * PLL. The sequence is:
> * 1. enable the pll, delay for 10us
> * 2. enable the pll self-adaption current module, delay for 40us
> * 3. enable the lock detect module
> */
Ok. I missed this is the PLL driver
>
> [...]
>
>> > +static struct clk_regmap fclk_div3 = {
>> > + .data = &(struct clk_regmap_gate_data){
>> > + .offset = ANACTRL_FIXPLL_CTRL0,
>> > + .bit_idx = 22,
>> > + },
>> > + .hw.init = &(struct clk_init_data){
>> > + .name = "fclk_div3",
>> > + .ops = &clk_regmap_gate_ops,
>> > + .parent_hws = (const struct clk_hw *[]) {
>> > + &fclk_div3_div.hw
>> > + },
>> > + .num_parents = 1,
>> > + /*
>> > + * This clock is used by APB bus which is set in boot ROM code
>> > + * and is required by the platform to operate correctly.
>> > + * About critical, refer to fclk_div2.
>>
>> This last line is not useful. Same for other occurences
>>
>
> Good point. Copy-paste detected :-)
>
> [...]
>
>> > +static int meson_a1_pll_probe(struct platform_device *pdev)
>> > +{
>> > + struct device *dev = &pdev->dev;
>> > + struct clk_hw *hw;
>> > + void __iomem *base;
>> > + struct regmap *map;
>> > + int clkid, i, err;
>> > +
>> > + base = devm_platform_ioremap_resource(pdev, 0);
>> > + if (IS_ERR(base))
>> > + return dev_err_probe(dev, PTR_ERR(base),
>> > + "can't ioremap resource\n");
>> > +
>> > + map = devm_regmap_init_mmio(dev, base, &a1_pll_regmap_cfg);
>> > + if (IS_ERR(map))
>> > + return dev_err_probe(dev, PTR_ERR(map),
>> > + "can't init regmap mmio region\n");
>> > +
>> > + /* Populate regmap for the regmap backed clocks */
>> > + for (i = 0; i < ARRAY_SIZE(a1_pll_regmaps); i++)
>> > + a1_pll_regmaps[i]->map = map;
>> > +
>> > + for (clkid = 0; clkid < a1_pll_hw_onecell_data.num; clkid++) {
>> > + hw = a1_pll_hw_onecell_data.hws[clkid];
>> > + err = devm_clk_hw_register(dev, hw);
>> > + if (err)
>> > + return dev_err_probe(dev, err,
>> > + "clock registration failed\n");
>> > + }
>> > +
>> > + return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
>> > + &a1_pll_hw_onecell_data);
>> > +}
>> > +
>> > +#ifdef CONFIG_OF
>>
>> This config is selected by ARM64 which this driver depends on
>>
>
> Make sense, thanks a lot!
>
> [...]
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