Re: [PATCH RESEND v7 3/4] clk: meson: add sub MMC clock controller driver

[Jerome Brunet <jbrunet@baylibre.com>]

On Thu, 2018-12-13 at 12:55 +0800, Jianxin Pan wrote:
> On 2018/12/12 0:59, Jerome Brunet wrote:
> > On Tue, 2018-12-11 at 00:04 +0800, Jianxin Pan wrote:
> > > From: Yixun Lan <yixun.lan@amlogic.com>
> > > 
> [...]
> > >  
> > > +config COMMON_CLK_MMC_MESON
> > > +	tristate "Meson MMC Sub Clock Controller Driver"
> > > +	select MFD_SYSCON
> > > +	select COMMON_CLK_AMLOGIC
> > > +	select COMMON_CLK_AMLOGIC_AUDIO
> > 
> > No it is wrong for the mmc to select AUDIO clocks.
> > If as a result of your patch sclk is needed for things, make the necessary
> > change in the Makefile.
> OK, I will add COMMON_CLK_AMLOGIC_SCLKDIV for sclk-div.

No! There is no reason to create a specific configuration for this.
please put it under COMMON_CLK_AMLOGIC

> [...]>> +#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 "clkc.h"
> > > +#include "clkc-audio.h"
> > 
> > Again having audio in the mmc controller is wrong.
> > Please make the necessary rework.
> Yes, I will split out sclk-div.h from clkc-audio.h in the next version.

Same, clkc.h will do

> Thanks for your time.
> > > +
> > > +/* clock ID used by internal driver */
> > > +#define CLKID_MMC_MUX			0
> > > +
> > > +#define   SD_EMMC_CLOCK		0
> >            ^
> > why the multiple space here ? this looks odd
> I will check the alignement  in the whole patchset and fix them, Thank you.
> > > +#define   CLK_DELAY_STEP_PS		200
> > 
> > Please keep thing aligned aligned consistently.
> > 
> > > +
> > > +#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;
> > 
> > Why use a tab above ?
> OK
> > > +};
> > > +
> > > +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,
> > > +		.shift   = (0),
> > > +		.width   = (6),
> > 
> > Please remove the unncessary parenthesis
> OK, I will remove them.
> > > +	},
> > > +	.hi = {
> > > +		.width   = 0,
> > > +	},
> > 
> > structure is a static const, all non-list members will be zero
> > drop the 
> OK, I will remove it in the next version. 
> > > +	.flags = 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,
> > > +		},
> > 
> > Again, an effort on alignement would appreciated, same below
> OK, I will fix them.
> > > +		.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;
> > > +
> > 
> > nitpick: remove this newline
> OK.
> > > +	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);
> > 
> > I don't think this cast is necessary     ^
> Yes, return clk is ok here.
> > > +		}
> > > +
> > > +		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 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, "Core %s clock registration failed\n", suffix);
> > 
> >                                ^
> > this function is not only called by the core clock, is it ?
> OK, I will drop "Core" in this line.
> > > +
> > > +	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*/
> > > +	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;
> > > +
> > > +	clk = mmc_clkc_register_mux(dev, map);
> > > +	if (IS_ERR(clk))
> > > +		return PTR_ERR(clk);
> > > +	onecell_data->hws[CLKID_MMC_MUX]		= &clk->hw,
> > 
> > It does not really need to have an ID or be in the onecell data if you are
> > not
> > going to expose it. On the other controllers, we are using the onecell for
> > the
> > registration as well, which is why there is unexpeosed IDs, but it is not
> > the
> > case here.
> > 
> > ... and please, stop with this unnecessary tab. a space will do. same
> > below.
> CLKID_MMC_MUX is an internal clock, and I will remove the ID and onecell
> date in the next version.
> And I will double check and fix tabs. Thank you.
> > > +
> > > +	div_data = devm_kzalloc(dev, sizeof(*div_data), GFP_KERNEL);
> > > +	if (!div_data)
> > > +		return -ENOMEM;
> > > +	*div_data = mmc_clkc_div_data;
> > 
> > memcpy would be more appropriate.
> Sure.
> > > +
> > > +	clk = mmc_clkc_register_clk_with_parent(dev, map, "div",
> > > +						&clk->hw,
> [...]
> > 
> > .
> >