Re: [PATCH v4 1/8] clk: renesas: r8a78000: Add clk_hw to clk_map

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Fri, Oct 16, 2026 at 05:55:40PM +0200, Geert Uytterhoeven wrote:
> Prepare for mapping to other than fixed-rate clocks by adding a clk_hw
> pointer to the clk_map structure, and populating it up-front.
> 
> Move r8a78000_cpg_priv.fixed_hws into fill_clk_map(), as it is no longer
> needed afterwards, and drop NUM_FIXED_CLKS.
> 
> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
> ---
> v4:
>   - No changes,
> 
> v3:
>   - New.
> ---
>  drivers/clk/renesas/r8a78000-cpg.c | 78 +++++++++++++++++++++---------
>  1 file changed, 56 insertions(+), 22 deletions(-)
> 
> diff --git a/drivers/clk/renesas/r8a78000-cpg.c b/drivers/clk/renesas/r8a78000-cpg.c
> index b8024e76743ea53d..5ffd7b89cb48e41c 100644
> --- a/drivers/clk/renesas/r8a78000-cpg.c
> +++ b/drivers/clk/renesas/r8a78000-cpg.c
> @@ -16,19 +16,24 @@
>  
>  #include <dt-bindings/clock/renesas,r8a78000-cpg.h>
>  
> +struct clk_map_in {

The "_in" suffix isn't very explicit.

> +	int dt_id;		/* DT binding clock ID or -1 sentinel */
> +	u32 fw_id;		/* FIXED_CLK() ID */
> +};
> +
>  struct clk_map {
>  	int dt_id;		/* DT binding clock ID or -1 sentinel */
>  	u32 fw_id;		/* FIXED_CLK() ID */
> +	struct clk_hw *hw;
>  };
>  
>  enum fixed_clk {
>  	FIXED_CLK_66M,
>  	FIXED_CLK_133M,
>  	FIXED_CLK_266M,
> -	NUM_FIXED_CLKS
>  };
>  
> -static const unsigned long fixed_clk_rates[NUM_FIXED_CLKS] = {
> +static const unsigned long fixed_clk_rates[] = {
>  	[FIXED_CLK_66M] = 66666000,
>  	[FIXED_CLK_133M] = 133330000,
>  	[FIXED_CLK_266M] = 266660000,
> @@ -41,12 +46,10 @@ static const unsigned long fixed_clk_rates[NUM_FIXED_CLKS] = {
>   *
>   * @dev: CPG device
>   * @map: Mapping from DT clock IDs to fixed-rate clocks
> - * @fixed_hws: Fixed rate clocks
>   */
>  struct r8a78000_cpg_priv {
>  	struct device *dev;
>  	const struct clk_map *map;
> -	struct clk_hw *fixed_hws[NUM_FIXED_CLKS];
>  };
>  
>  static const struct clk_map *clk_map_find(const struct clk_map *map, u32 id)
> @@ -83,8 +86,7 @@ static struct clk_hw *r8a78000_clk_get(struct of_phandle_args *spec,
>  	}
>  
>  	dev_dbg(dev, "Mapping DT clock %u to fixed clock %u\n", id, map->fw_id);
> -
> -	hw = priv->fixed_hws[map->fw_id];
> +	hw = map->hw;
>  
>  	dev_dbg(dev, "clock %u is %s at %lu Hz\n", id, clk_hw_get_name(hw),
>  		clk_hw_get_rate(hw));
> @@ -92,35 +94,69 @@ static struct clk_hw *r8a78000_clk_get(struct of_phandle_args *spec,
>  	return hw;
>  }
>  
> -static int register_fixed_clks(struct r8a78000_cpg_priv *priv)
> +static struct clk_hw **register_fixed_clks(struct device *dev)
>  {
> -	struct device *dev = priv->dev;
> +	unsigned int n = ARRAY_SIZE(fixed_clk_rates);
> +	struct clk_hw **hws, *hw;
>  	unsigned long rate;
> -	struct clk_hw *hw;
>  	const char *name;
>  
> -	for (unsigned int i = 0; i < ARRAY_SIZE(fixed_clk_rates); i++) {
> +	hws = devm_kcalloc(dev, n, sizeof(*hws), GFP_KERNEL);
> +	if (!hws)
> +		return ERR_PTR(-ENOMEM);
> +
> +	for (unsigned int i = 0; i < n; i++) {
>  		rate = fixed_clk_rates[i];
>  		name = devm_kasprintf(dev, GFP_KERNEL, "cpg-%lu", rate);
>  		if (!name)
> -			return -ENOMEM;
> +			return ERR_PTR(-ENOMEM);
>  
>  		hw = devm_clk_hw_register_fixed_rate(dev, name, NULL, 0, rate);
>  		if (IS_ERR(hw))
> -			return PTR_ERR(hw);
> +			return ERR_CAST(hw);
>  
> -		priv->fixed_hws[i] = hw;
> +		hws[i] = hw;
>  	}
>  
> -	return 0;
> +	return hws;
> +}
> +
> +static const struct clk_map *fill_clk_map(struct r8a78000_cpg_priv *priv,
> +					  const struct clk_map_in *map_in)
> +{
> +	struct device *dev = priv->dev;
> +	struct clk_hw **fixed_hws;
> +	struct clk_map *map;
> +	unsigned int i;
> +
> +	fixed_hws = register_fixed_clks(dev);
> +	if (IS_ERR(fixed_hws))
> +		return ERR_CAST(fixed_hws);
> +
> +	for (i = 0; map_in[i].dt_id >= 0; i++) { }

This is avoidable by passing { map, ARRAY_SIZE(map) } as match data
instead of just the map.

> +
> +	map = devm_kcalloc(dev, i + 1, sizeof(*map), GFP_KERNEL);
> +	if (!map)
> +		return ERR_PTR(-ENOMEM);
> +
> +	for (i = 0; ; i++) {
> +		map[i].dt_id = map_in[i].dt_id;
> +		if (map[i].dt_id < 0)
> +			break;
> +
> +		map[i].fw_id = map_in[i].fw_id;
> +		map[i].hw = fixed_hws[map[i].fw_id];
> +	}
> +
> +	devm_kfree(dev, fixed_hws);

Why not plain kcalloc/kfree ?

> +	return map;
>  }
>  
>  static int r8a78000_cpg_probe(struct platform_device *pdev)
>  {
>  	struct device *dev = &pdev->dev;
>  	struct r8a78000_cpg_priv *priv;
> -	const struct clk_map *map;
> -	int ret;
> +	const struct clk_map_in *map;
>  
>  	map = of_device_get_match_data(dev);
>  	if (!map)
> @@ -131,16 +167,14 @@ static int r8a78000_cpg_probe(struct platform_device *pdev)
>  		return -ENOMEM;
>  
>  	priv->dev = dev;
> -	priv->map = map;
> -
> -	ret = register_fixed_clks(priv);
> -	if (ret)
> -		return ret;
> +	priv->map = fill_clk_map(priv, map);
> +	if (IS_ERR(priv->map))
> +		return PTR_ERR(priv->map);
>  
>  	return devm_of_clk_add_hw_provider(dev, r8a78000_clk_get, priv);
>  }
>  
> -static const struct clk_map r8a78000_cpg_default[] = {
> +static const struct clk_map_in r8a78000_cpg_default[] = {
>  	{ R8A78000_CPG_SGASYNCD4_PERW_BUS,	FIXED_CLK(266M) },
>  	{ R8A78000_CPG_SGASYNCD8_PERW_BUS,	FIXED_CLK(133M) },
>  	{ R8A78000_CPG_SGASYNCD16_PERW_BUS,	FIXED_CLK(66M) },

-- 
Regards,

Laurent Pinchart