[PATCH v9 4/4] clk: meson: add sub MMC clock controller driver
Liang Yang
liang.yang at amlogic.com
Thu Jan 13 21:14:46 PST 2022
Hi Stephen,
On 2022/1/14 5:35, Stephen Boyd wrote:
> [ EXTERNAL EMAIL ]
>
> Quoting Liang Yang (2022-01-13 03:57:45)
>> diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
>> index bb0f59eea366..3de6f3b24461 100644
>> --- a/drivers/clk/meson/Kconfig
>> +++ b/drivers/clk/meson/Kconfig
>> @@ -39,6 +39,20 @@ config COMMON_CLK_MESON_AO_CLKC
>> select COMMON_CLK_MESON_REGMAP
>> select RESET_CONTROLLER
>>
>> +config COMMON_CLK_MMC_MESON
>> + tristate "Meson MMC Sub Clock Controller Driver"
>> + depends on ARCH_MESON || COMPILE_TEST
>> + select MFD_SYSCON
>> + select COMMON_CLK_AMLOGIC
>> + select COMMON_CLK_MESON_PHASE
>> + select COMMON_CLK_MESON_PHASE_DELAY
>> + select COMMON_CLK_MESON_SCLK_DIV
>> + help
>> + Support for the MMC sub clock controller on
>> + Amlogic Meson Platform, which includes S905 (GXBB, GXL),
>> + A113D/X (AXG) devices . Say Y if you want this
>
> s/devices /devices/
ok, i will fix it
>
>> + clock enabled.
>> +
>> config COMMON_CLK_MESON_EE_CLKC
>> tristate
>> select COMMON_CLK_MESON_REGMAP
>> diff --git a/drivers/clk/meson/mmc-clkc.c b/drivers/clk/meson/mmc-clkc.c
>> new file mode 100644
>> index 000000000000..f53977f61390
>> --- /dev/null
>> +++ b/drivers/clk/meson/mmc-clkc.c
>> @@ -0,0 +1,300 @@
>> +// SPDX-License-Identifier: (GPL-2.0+ OR MIT)
>> +/*
>> + * Copyright (c) 2019 Amlogic, Inc. All rights reserved.
>> + */
>> +
>> +#include <linux/clk.h>
>> +#include <linux/clk-provider.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 "sclk-div.h"
>> +#include "clk-phase-delay.h"
>> +#include "clk-regmap.h"
>> +#include "clk-phase.h"
>> +
>> +/* clock ID used by internal driver */
>> +
>> +#define SD_EMMC_CLOCK 0
>> +#define CLK_DELAY_STEP_PS_GX 200
>> +#define CLK_DELAY_STEP_PS_AXG 78
>> +#define MUX_CLK_NUM_PARENTS 2
>> +#define MMC_MAX_CLKS 4
>> +
>> +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,
>> +};
>> +
>> +static const struct meson_sclk_div_data mmc_clkc_div_data = {
>> + .div = {
>> + .reg_off = SD_EMMC_CLOCK,
>> + .width = 6,
>> + },
>> + .flags = MESON_SCLK_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_GX,
>> + },
>> + .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_GX,
>> + },
>> +};
>> +
>> +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_AXG,
>> + },
>> + .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_AXG,
>> + },
>> +};
>> +
>> +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);
>
> Use dev_err_probe()?
ok
>
>> + return ERR_CAST(clk);
>> + }
>> +
>> + parent_names[i] = __clk_get_name(clk);
>
> Why can't we use clk_parent_data?
ok, i will try clk_parent_data.
>
>> + }
>> +
>> + 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 struct clk_hw *hw,
>> + unsigned long flags,
>> + const struct clk_ops *ops, void *data)
>> +{
>> + struct clk_init_data init;
>> + struct clk_regmap *clk;
>> + const char *parent_name = clk_hw_get_name(hw);
>> +
>> + init.ops = ops;
>> + init.flags = flags;
>> + init.parent_names = &parent_name;
>> + init.num_parents = 1;
>> +
>> + clk = mmc_clkc_register_clk(dev, map, &init, suffix, data);
>> + if (IS_ERR(clk))
>> + dev_err(dev, "%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 *clk, *core;
>> + struct meson_sclk_div_data *div_data;
>> +
>> + /*cast to drop the const in match->data*/
>
> Space after *, also why do we need to cast away const? The user of this
> pointer passes it all the way down to mmc_clkc_register_clk() which
> could take the data as const void pointer and decide to cast away const
> there.
if use 'const' here, it will report a warning:
drivers/clk/meson/mmc-clkc.c:224:7: error: assignment discards ‘const’
qualifier from pointer targe
t type [-Werror=discarded-qualifiers]
data = (const struct mmc_clkc_data *)of_device_get_match_data(dev);
>
>> + 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,
>> + struct_size(onecell_data, hws,
>> + MMC_MAX_CLKS),
>> + GFP_KERNEL);
>> + if (!onecell_data)
>> + return -ENOMEM;
>> +
>> + clk = mmc_clkc_register_mux(dev, map);
>> + if (IS_ERR(clk))
>> + return PTR_ERR(clk);
>> +
>> + div_data = devm_kzalloc(dev, sizeof(*div_data), GFP_KERNEL);
>> + if (!div_data)
>> + return -ENOMEM;
>> +
>> + memcpy(div_data, &mmc_clkc_div_data, sizeof(*div_data));
>> + clk = mmc_clkc_register_clk_with_parent(dev, map, "div",
>> + &clk->hw,
>> + CLK_SET_RATE_PARENT,
>> + &meson_sclk_div_ops,
>> + div_data);
>> + if (IS_ERR(clk))
>> + return PTR_ERR(clk);
>> +
>> + onecell_data->hws[CLKID_MMC_DIV] = &clk->hw;
>> + core = mmc_clkc_register_clk_with_parent(dev, map, "core",
>> + &clk->hw,
>> + CLK_SET_RATE_PARENT,
>> + &meson_clk_phase_ops,
>> + &mmc_clkc_core_phase);
>> + if (IS_ERR(core))
>> + return PTR_ERR(core);
>> +
>> + onecell_data->hws[CLKID_MMC_PHASE_CORE] = &core->hw;
>> + clk = mmc_clkc_register_clk_with_parent(dev, map, "rx",
>> + &core->hw, 0,
>> + &meson_clk_phase_delay_ops,
>> + &data->rx);
>> + if (IS_ERR(clk))
>> + return PTR_ERR(clk);
>> +
>> + onecell_data->hws[CLKID_MMC_PHASE_RX] = &clk->hw;
>> + clk = mmc_clkc_register_clk_with_parent(dev, map, "tx",
>> + &core->hw, 0,
>> + &meson_clk_phase_delay_ops,
>> + &data->tx);
>> + if (IS_ERR(clk))
>> + return PTR_ERR(clk);
>> +
>> + onecell_data->hws[CLKID_MMC_PHASE_TX] = &clk->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);
>> +
>> +MODULE_DESCRIPTION("Amlogic AXG MMC clock driver");
>> +MODULE_AUTHOR("Jianxin Pan <jianxin.pan at amlogic.com>");
>> +MODULE_LICENSE("GPL v2");
>
> .
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