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SubjectRe: [PATCH v4 3/3] clk: meson: add sub MMC clock controller driver
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On Thu, 2018-08-09 at 15:07 +0800, Yixun Lan wrote:
> 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.
>
> Two clocks are provided as the parent of MMC clock controller from
> upper layer clock controller - eg "amlogic,axg-clkc" in AXG platform.
>
> To specify which clock the MMC or NAND driver may consume,
> the preprocessor macros in the dt-bindings/clock/amlogic,mmc-clkc.h header
> can be used in the device tree sources.
>
> Signed-off-by: Yixun Lan <yixun.lan@amlogic.com>
> ---
> drivers/clk/meson/Kconfig | 10 ++
> drivers/clk/meson/Makefile | 1 +
> drivers/clk/meson/mmc-clkc.c | 275 +++++++++++++++++++++++++++++++++++
> 3 files changed, 286 insertions(+)
> create mode 100644 drivers/clk/meson/mmc-clkc.c
>
> diff --git a/drivers/clk/meson/Kconfig b/drivers/clk/meson/Kconfig
> index efaa70f682b4..8b8ccbcfed1d 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
> + select MFD_SYSCON
> + select REGMAP
> + 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 39ce5661b654..31c16d524a4b 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/mmc-clkc.c b/drivers/clk/meson/mmc-clkc.c
> new file mode 100644
> index 000000000000..6aa055f7e62c
> --- /dev/null
> +++ b/drivers/clk/meson/mmc-clkc.c
> @@ -0,0 +1,275 @@
> +// 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_DIV_MASK GENMASK(5, 0)
> +#define CLK_SRC_MASK GENMASK(7, 6)
> +#define CLK_CORE_PHASE_MASK GENMASK(9, 8)
> +#define CLK_TX_PHASE_MASK GENMASK(11, 10)
> +#define CLK_RX_PHASE_MASK GENMASK(13, 12)
> +#define CLK_V2_TX_DELAY_MASK GENMASK(19, 16)
> +#define CLK_V2_RX_DELAY_MASK GENMASK(23, 20)
> +#define CLK_V2_ALWAYS_ON BIT(24)
> +
> +#define CLK_V3_TX_DELAY_MASK GENMASK(21, 16)
> +#define CLK_V3_RX_DELAY_MASK GENMASK(27, 22)
> +#define CLK_V3_ALWAYS_ON BIT(28)
> +
> +#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_delay_data mmc_clkc_core_phase_delay = {
> + .phase_mask = CLK_CORE_PHASE_MASK,
> +};
> +
> +static const struct mmc_clkc_data mmc_clkc_gx_data = {
> + {
> + .phase_mask = CLK_TX_PHASE_MASK,
> + .delay_mask = CLK_V2_TX_DELAY_MASK,
> + .delay_step_ps = CLK_DELAY_STEP_PS,
> + },
> + {
> + .phase_mask = CLK_RX_PHASE_MASK,
> + .delay_mask = CLK_V2_RX_DELAY_MASK,
> + .delay_step_ps = CLK_DELAY_STEP_PS,
> + },
> +};
> +
> +static const struct mmc_clkc_data mmc_clkc_axg_data = {
> + {
> + .phase_mask = CLK_TX_PHASE_MASK,
> + .delay_mask = CLK_V3_TX_DELAY_MASK,
> + .delay_step_ps = CLK_DELAY_STEP_PS,
> + },
> + {
> + .phase_mask = CLK_RX_PHASE_MASK,
> + .delay_mask = CLK_V3_RX_DELAY_MASK,
> + .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_other_clk(struct device *dev, struct regmap *map,

This is a poor name. It does not help understand what the function does.
mmc_clkc_register_clk_with_parent or whatever helps understand what's going on

> + char *suffix, char *parent_suffix,

You should not have to rebuild the parent name once again.
Pass the clk_hw* of the parent and get the name from it.

> + unsigned long flags,
> + const struct clk_ops *ops, void *data)
> +{
> + struct clk_init_data init;
> + struct clk_regmap *clk;
> + char *parent;
> +
> + parent = kasprintf(GFP_KERNEL, "%s#%s", dev_name(dev), parent_suffix);
> + if (!parent)
> + return ERR_PTR(-ENOMEM);
> +
> + 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);
> +
> + kfree(parent);
> + 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;

Do you really need all this ? or could store them in your onecell_data->hws
table as you go ?

> +
> + 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_other_clk(dev, map, "div", "mux",
> + CLK_SET_RATE_PARENT,
> + &clk_regmap_divider_ops,
> + &mmc_clkc_div_data);
> + if (IS_ERR(div))
> + return PTR_ERR(div);
> +
> + core = mmc_clkc_register_other_clk(dev, map, "core", "div",
> + CLK_SET_RATE_PARENT,
> + &meson_clk_phase_delay_ops,
> + &mmc_clkc_core_phase_delay);
> + if (IS_ERR(core))
> + return PTR_ERR(core);
> +
> + rx = mmc_clkc_register_other_clk(dev, map, "rx", "core", 0,
> + &meson_clk_phase_delay_ops,
> + &data->rx);
> + if (IS_ERR(rx))
> + return PTR_ERR(rx);
> +
> + tx = mmc_clkc_register_other_clk(dev, map, "tx", "core", 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);


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