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....@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 <jbru...@baylibre.com>
>> + *
>> + * Copyright (c) 2018 Amlogic, inc.
>> + * Author: Yixun Lan <yixun....@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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