[PATCH v9 2/5] clk: meson: a1: add Amlogic A1 PLL clock controller driver
Dmitry Rokosov
ddrokosov at sberdevices.ru
Mon Mar 6 12:05:49 PST 2023
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
.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
*/
[...]
> > +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!
[...]
--
Thank you,
Dmitry
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