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SubjectRe: [PATCH v5 3/3] clk: meson: add sub MMC clock controller driver
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Hi Jerome,

On 2018/10/24 17:01, Jerome Brunet wrote:
> On Thu, 2018-10-18 at 13:07 +0800, Jianxin Pan wrote:
>> From: Yixun Lan <yixun.lan@amlogic.com>
>>
>> The patch will add a MMC clock controller driver which used by MMC or NAND,
>> It provide a mux and divider clock, and three phase clocks - core, tx, tx.
>>
[...]
>> diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
>> index efaa70f..8b8ccbc 100644
>> --- a/drivers/clk/meson/Kconfig
>> +++ b/drivers/clk/meson/Kconfig
>> @@ -15,6 +15,16 @@ config COMMON_CLK_MESON_AO
>> select COMMON_CLK_REGMAP_MESON
>> select RESET_CONTROLLER
>>
>> +config COMMON_CLK_MMC_MESON
>> + tristate "Meson MMC Sub Clock Controller Driver"
>> + depends on COMMON_CLK_AMLOGIC
>
> COMMON_CLK_AMLOGIC is not something that is manually enabled
> You should select it, not depends on it. Have a look at how it is done for the
> other controller (like in v4.19)
OK. I will fix it.
>
>> + select MFD_SYSCON
>> + select REGMAP
>
> this is already selected by COMMON_CLK_AMLOGIC, please drop this.
OK.
>
>> + help
>> + Support for the MMC sub clock controller on Amlogic Meson Platform,
>> + which include S905 (GXBB, GXL), A113D/X (AXG) devices.
>> + Say Y if you want this clock enabled.
>> +
>> config COMMON_CLK_REGMAP_MESON
>> bool
>> select REGMAP
>> diff --git a/drivers/clk/meson/Makefile b/drivers/clk/meson/Makefile
>> index 39ce566..31c16d5 100644
>> --- a/drivers/clk/meson/Makefile
>> +++ b/drivers/clk/meson/Makefile
>> @@ -9,4 +9,5 @@ obj-$(CONFIG_COMMON_CLK_MESON8B) += meson8b.o
>> obj-$(CONFIG_COMMON_CLK_GXBB) += gxbb.o gxbb-aoclk.o gxbb-aoclk-32k.o
>> obj-$(CONFIG_COMMON_CLK_AXG) += axg.o axg-aoclk.o
>> obj-$(CONFIG_COMMON_CLK_AXG_AUDIO) += axg-audio.o
>> +obj-$(CONFIG_COMMON_CLK_MMC_MESON) += mmc-clkc.o
>> obj-$(CONFIG_COMMON_CLK_REGMAP_MESON) += clk-regmap.o
>> diff --git a/drivers/clk/meson/clk-regmap.c b/drivers/clk/meson/clk-regmap.c
>> index 305ee30..f96314d 100644
>> --- a/drivers/clk/meson/clk-regmap.c
>> +++ b/drivers/clk/meson/clk-regmap.c
>> @@ -113,8 +113,25 @@ static int clk_regmap_div_set_rate(struct clk_hw *hw, unsigned long rate,
>> clk_div_mask(div->width) << div->shift, val);
>> };
>>
>> -/* Would prefer clk_regmap_div_ro_ops but clashes with qcom */
>> +static void clk_regmap_div_init(struct clk_hw *hw)
>> +{
>> + struct clk_regmap *clk = to_clk_regmap(hw);
>> + struct clk_regmap_div_data *div = clk_get_regmap_div_data(clk);
>> + unsigned int val;
>> + int ret;
>> +
>> + ret = regmap_read(clk->map, div->offset, &val);
>> + if (ret)
>> + return;
>>
>> + val &= (clk_div_mask(div->width) << div->shift);
>> + if (!val)
>> + regmap_update_bits(clk->map, div->offset,
>> + clk_div_mask(div->width) << div->shift,
>> + clk_div_mask(div->width));
>
> This is wrong for several reasons:
> * You should hard code the initial value in the driver.
> * If shift is not 0, I doubt this will give the expected result.
The value 0x00 of divider means nand clock off, then read/write nand register is forbidden.
Should we set the initial value in nand driver, or in sub emmc clk driver?
>
>> +}
>
> Please drop this.
>
>> +
>> +/* Would prefer clk_regmap_div_ro_ops but clashes with qcom */
>> const struct clk_ops clk_regmap_divider_ops = {
>> .recalc_rate = clk_regmap_div_recalc_rate,
>> .round_rate = clk_regmap_div_round_rate,
>> @@ -122,6 +139,14 @@ static int clk_regmap_div_set_rate(struct clk_hw *hw, unsigned long rate,
>> };
>> EXPORT_SYMBOL_GPL(clk_regmap_divider_ops);
>>
>> +const struct clk_ops clk_regmap_divider_with_init_ops = {
>> + .recalc_rate = clk_regmap_div_recalc_rate,
>> + .round_rate = clk_regmap_div_round_rate,
>> + .set_rate = clk_regmap_div_set_rate,
>> + .init = clk_regmap_div_init,
>> +};
>> +EXPORT_SYMBOL_GPL(clk_regmap_divider_with_init_ops);
>
> ... and this.
>
>> +
>> const struct clk_ops clk_regmap_divider_ro_ops = {
>> .recalc_rate = clk_regmap_div_recalc_rate,
>> .round_rate = clk_regmap_div_round_rate,
>> diff --git a/drivers/clk/meson/clk-regmap.h b/drivers/clk/meson/clk-regmap.h
>> index ed2d434..0ab7d37 100644
>> --- a/drivers/clk/meson/clk-regmap.h
>> +++ b/drivers/clk/meson/clk-regmap.h
>> @@ -109,5 +109,6 @@ struct clk_regmap_mux_data {
>>
>> extern const struct clk_ops clk_regmap_mux_ops;
>> extern const struct clk_ops clk_regmap_mux_ro_ops;
>> +extern const struct clk_ops clk_regmap_divider_with_init_ops;
>
> ... and this as well.
>
> There is no reason to to init the divider to something other than what it is
> already when we register the clock controller.
>
> If your consumer needs the clocks to be initialised, it should call
> clk_set_rate()
>
>>
>> #endif /* __CLK_REGMAP_H */
>> diff --git a/drivers/clk/meson/mmc-clkc.c b/drivers/clk/meson/mmc-clkc.c
>> new file mode 100644
>> index 0000000..5555e3f
>> --- /dev/null
>> +++ b/drivers/clk/meson/mmc-clkc.c
>> @@ -0,0 +1,296 @@
>> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
>> +/*
>> + * Amlogic Meson MMC Sub Clock Controller Driver
>> + *
>> + * Copyright (c) 2017 Baylibre SAS.
>> + * Author: Jerome Brunet <jbrunet@baylibre.com>
>> + *
>> + * Copyright (c) 2018 Amlogic, inc.
>> + * Author: Yixun Lan <yixun.lan@amlogic.com>
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/module.h>
>> +#include <linux/regmap.h>
>> +#include <linux/slab.h>
>> +#include <linux/of_device.h>
>> +#include <linux/mfd/syscon.h>
>> +#include <linux/platform_device.h>
>> +#include <dt-bindings/clock/amlogic,mmc-clkc.h>
>> +
>> +#include "clkc.h"
>> +
>> +/* clock ID used by internal driver */
>> +#define CLKID_MMC_MUX 0
>> +
>> +#define SD_EMMC_CLOCK 0
>> +#define CLK_DELAY_STEP_PS 200
>> +#define CLK_PHASE_STEP 30
>> +#define CLK_PHASE_POINT_NUM (360 / CLK_PHASE_STEP)
>> +
>> +#define MUX_CLK_NUM_PARENTS 2
>> +#define MMC_MAX_CLKS 5
>> +
>> +struct mmc_clkc_data {
>> + struct meson_clk_phase_delay_data tx;
>> + struct meson_clk_phase_delay_data rx;
>> +};
>> +
>> +static struct clk_regmap_mux_data mmc_clkc_mux_data = {
>> + .offset = SD_EMMC_CLOCK,
>> + .mask = 0x3,
>> + .shift = 6,
>> + .flags = CLK_DIVIDER_ROUND_CLOSEST,
>> +};
>> +
>> +static struct clk_regmap_div_data mmc_clkc_div_data = {
>> + .offset = SD_EMMC_CLOCK,
>> + .shift = 0,
>> + .width = 6,
>> + .flags = CLK_DIVIDER_ROUND_CLOSEST | CLK_DIVIDER_ONE_BASED,
>> +};
>> +
>> +static struct meson_clk_phase_data mmc_clkc_core_phase = {
>> + .ph = {
>> + .reg_off = SD_EMMC_CLOCK,
>> + .shift = 8,
>> + .width = 2,
>> + }
>> +};
>> +
>> +static const struct mmc_clkc_data mmc_clkc_gx_data = {
>> + .tx = {
>> + .phase = {
>> + .reg_off = SD_EMMC_CLOCK,
>> + .shift = 10,
>> + .width = 2,
>> + },
>> + .delay = {
>> + .reg_off = SD_EMMC_CLOCK,
>> + .shift = 16,
>> + .width = 4,
>> + },
>> + .delay_step_ps = CLK_DELAY_STEP_PS,
>> + },
>> + .rx = {
>> + .phase = {
>> + .reg_off = SD_EMMC_CLOCK,
>> + .shift = 12,
>> + .width = 2,
>> + },
>> + .delay = {
>> + .reg_off = SD_EMMC_CLOCK,
>> + .shift = 20,
>> + .width = 4,
>> + },
>> + .delay_step_ps = CLK_DELAY_STEP_PS,
>> + },
>> +};
>> +
>> +static const struct mmc_clkc_data mmc_clkc_axg_data = {
>> + .tx = {
>> + .phase = {
>> + .reg_off = SD_EMMC_CLOCK,
>> + .shift = 10,
>> + .width = 2,
>> + },
>> + .delay = {
>> + .reg_off = SD_EMMC_CLOCK,
>> + .shift = 16,
>> + .width = 6,
>> + },
>> + .delay_step_ps = CLK_DELAY_STEP_PS,
>> + },
>> + .rx = {
>> + .phase = {
>> + .reg_off = SD_EMMC_CLOCK,
>> + .shift = 12,
>> + .width = 2,
>> + },
>> + .delay = {
>> + .reg_off = SD_EMMC_CLOCK,
>> + .shift = 22,
>> + .width = 6,
>> + },
>> + .delay_step_ps = CLK_DELAY_STEP_PS,
>> + },
>> +};
>> +
>> +static const struct of_device_id mmc_clkc_match_table[] = {
>> + {
>> + .compatible = "amlogic,gx-mmc-clkc",
>> + .data = &mmc_clkc_gx_data
>> + },
>> + {
>> + .compatible = "amlogic,axg-mmc-clkc",
>> + .data = &mmc_clkc_axg_data
>> + },
>> + {}
>> +};
>> +MODULE_DEVICE_TABLE(of, mmc_clkc_match_table);
>> +
>> +static struct clk_regmap *
>> +mmc_clkc_register_clk(struct device *dev, struct regmap *map,
>> + struct clk_init_data *init,
>> + const char *suffix, void *data)
>> +{
>> + struct clk_regmap *clk;
>> + char *name;
>> + int ret;
>> +
>> + clk = devm_kzalloc(dev, sizeof(*clk), GFP_KERNEL);
>> + if (!clk)
>> + return ERR_PTR(-ENOMEM);
>> +
>> + name = kasprintf(GFP_KERNEL, "%s#%s", dev_name(dev), suffix);
>> + if (!name)
>> + return ERR_PTR(-ENOMEM);
>> +
>> + init->name = name;
>> +
>> + clk->map = map;
>> + clk->data = data;
>> + clk->hw.init = init;
>> +
>> + ret = devm_clk_hw_register(dev, &clk->hw);
>> + if (ret)
>> + clk = ERR_PTR(ret);
>> +
>> + kfree(name);
>> + return clk;
>> +}
>> +
>> +static struct clk_regmap *mmc_clkc_register_mux(struct device *dev,
>> + struct regmap *map)
>> +{
>> + const char *parent_names[MUX_CLK_NUM_PARENTS];
>> + struct clk_init_data init;
>> + struct clk_regmap *mux;
>> + struct clk *clk;
>> + int i;
>> +
>> + for (i = 0; i < MUX_CLK_NUM_PARENTS; i++) {
>> + char name[8];
>> +
>> + snprintf(name, sizeof(name), "clkin%d", i);
>> + clk = devm_clk_get(dev, name);
>> + if (IS_ERR(clk)) {
>> + if (clk != ERR_PTR(-EPROBE_DEFER))
>> + dev_err(dev, "Missing clock %s\n", name);
>> + return ERR_PTR((long)clk);
>> + }
>> +
>> + parent_names[i] = __clk_get_name(clk);
>> + }
>> +
>> + init.ops = &clk_regmap_mux_ops;
>> + init.flags = CLK_SET_RATE_PARENT;
>> + init.parent_names = parent_names;
>> + init.num_parents = MUX_CLK_NUM_PARENTS;
>> +
>> + mux = mmc_clkc_register_clk(dev, map, &init, "mux", &mmc_clkc_mux_data);
>> + if (IS_ERR(mux))
>> + dev_err(dev, "Mux clock registration failed\n");
>> +
>> + return mux;
>> +}
>> +
>> +static struct clk_regmap *
>> +mmc_clkc_register_clk_with_parent(struct device *dev, struct regmap *map,
>> + char *suffix, const char *parent,
>
> I would prefer if you passed the parent clk_hw pointer and call
> clk_hw_get_name() in here
OK. I will fix it. Thanks for your review.
>
>> + unsigned long flags,
>> + const struct clk_ops *ops, void *data)
>> +{
>> + struct clk_init_data init;
>> + struct clk_regmap *clk;
>> +
>> + init.ops = ops;
>> + init.flags = flags;
>> + init.parent_names = (const char* const []){ parent, };
>> + init.num_parents = 1;
>> +
>> + clk = mmc_clkc_register_clk(dev, map, &init, suffix, data);
>> + if (IS_ERR(clk))
>> + dev_err(dev, "Core %s clock registration failed\n", suffix);
>> +
>> + return clk;
>> +}
>> +
>> +static int mmc_clkc_probe(struct platform_device *pdev)
>> +{
>> + struct clk_hw_onecell_data *onecell_data;
>> + struct device *dev = &pdev->dev;
>> + struct mmc_clkc_data *data;
>> + struct regmap *map;
>> + struct clk_regmap *mux, *div, *core, *rx, *tx;
>
> You really don't need all these local variables ( I think I already pointed this
> out in past reviews ...)
>
> You can keep one struct clk_regmap *clk and store the clk->hw in the onecell
> data right after registering the clock.
OK, I will remove them.
>
>
>> +
>> + data = (struct mmc_clkc_data *)of_device_get_match_data(dev);
>> + if (!data)
>> + return -ENODEV;
>> +
>> + map = syscon_node_to_regmap(dev->of_node);
>> + if (IS_ERR(map)) {
>> + dev_err(dev, "could not find mmc clock controller\n");
>> + return PTR_ERR(map);
>> + }
>> +
>> + onecell_data = devm_kzalloc(dev, sizeof(*onecell_data) +
>> + sizeof(*onecell_data->hws) * MMC_MAX_CLKS,
>> + GFP_KERNEL);
>> + if (!onecell_data)
>> + return -ENOMEM;
>> +
>> + mux = mmc_clkc_register_mux(dev, map);
>> + if (IS_ERR(mux))
>> + return PTR_ERR(mux);
>> +
>> + div = mmc_clkc_register_clk_with_parent(dev, map, "div",
>> + clk_hw_get_name(&mux->hw),
>> + CLK_SET_RATE_PARENT,
>> + &clk_regmap_divider_with_init_ops,
>> + &mmc_clkc_div_data);
>> + if (IS_ERR(div))
>> + return PTR_ERR(div);
>> +
>> + core = mmc_clkc_register_clk_with_parent(dev, map, "core",
>> + clk_hw_get_name(&div->hw),
>> + CLK_SET_RATE_PARENT,
>> + &meson_clk_phase_ops,
>> + &mmc_clkc_core_phase);
>> + if (IS_ERR(core))
>> + return PTR_ERR(core);
>> +
>> + rx = mmc_clkc_register_clk_with_parent(dev, map, "rx",
>> + clk_hw_get_name(&core->hw), 0,
>> + &meson_clk_phase_delay_ops,
>> + &data->rx);
>> + if (IS_ERR(rx))
>> + return PTR_ERR(rx);
>> +
>> + tx = mmc_clkc_register_clk_with_parent(dev, map, "tx",
>> + clk_hw_get_name(&core->hw), 0,
>> + &meson_clk_phase_delay_ops,
>> + &data->tx);
>> + if (IS_ERR(tx))
>> + return PTR_ERR(tx);
>> +
>> + onecell_data->hws[CLKID_MMC_MUX] = &mux->hw,
>> + onecell_data->hws[CLKID_MMC_DIV] = &div->hw,
>> + onecell_data->hws[CLKID_MMC_PHASE_CORE] = &core->hw,
>> + onecell_data->hws[CLKID_MMC_PHASE_RX] = &rx->hw,
>> + onecell_data->hws[CLKID_MMC_PHASE_TX] = &tx->hw,
>> + onecell_data->num = MMC_MAX_CLKS;
>> +
>> + return devm_of_clk_add_hw_provider(dev, of_clk_hw_onecell_get,
>> + onecell_data);
>> +}
>> +
>> +static struct platform_driver mmc_clkc_driver = {
>> + .probe = mmc_clkc_probe,
>> + .driver = {
>> + .name = "meson-mmc-clkc",
>> + .of_match_table = of_match_ptr(mmc_clkc_match_table),
>> + },
>> +};
>> +
>> +module_platform_driver(mmc_clkc_driver);
>
> This can be compiled as module so please append the proper:
> MODULE_DESCRIPTION()
> MODULE_AUTHOR()
> MODULE_LICENSE()
OK. I will fix it in the next version.
>
> .
>

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