Re: [PATCH v3 4/8] cpufreq: sun50i: Refactor speed bin decoding

["Jernej Škrabec" <jernej.skrabec@gmail.com>]

Dne torek, 26. marec 2024 ob 12:47:39 CET je Andre Przywara napisal(a):
> From: Brandon Cheo Fusi <fusibrandon13@gmail.com>
> 
> Make converting the speed bin value into a speed grade generic and
> determined by a platform specific callback. Also change the prototypes
> involved to encode the speed bin directly in the return value.
> 
> This allows to extend the driver more easily to support more SoCs.
> 
> Signed-off-by: Brandon Cheo Fusi <fusibrandon13@gmail.com>
> [Andre: merge output into return value]
> Signed-off-by: Andre Przywara <andre.przywara@arm.com>
> ---
>  drivers/cpufreq/sun50i-cpufreq-nvmem.c | 74 +++++++++++++++++---------
>  1 file changed, 49 insertions(+), 25 deletions(-)
> 
> diff --git a/drivers/cpufreq/sun50i-cpufreq-nvmem.c b/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> index 32a9c88f8ff6d..7b44f3b13e7d2 100644
> --- a/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> +++ b/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> @@ -25,19 +25,52 @@
>  
>  static struct platform_device *cpufreq_dt_pdev, *sun50i_cpufreq_pdev;
>  
> +struct sunxi_cpufreq_data {
> +	u32 (*efuse_xlate)(u32 speedbin);
> +};
> +
> +static u32 sun50i_h6_efuse_xlate(u32 speedbin)
> +{
> +	u32 efuse_value;
> +
> +	efuse_value = (speedbin >> NVMEM_SHIFT) & NVMEM_MASK;
> +
> +	/*
> +	 * We treat unexpected efuse values as if the SoC was from
> +	 * the slowest bin. Expected efuse values are 1-3, slowest
> +	 * to fastest.
> +	 */
> +	if (efuse_value >= 1 && efuse_value <= 3)
> +		return efuse_value - 1;
> +	else
> +		return 0;
> +}
> +
> +static struct sunxi_cpufreq_data sun50i_h6_cpufreq_data = {
> +	.efuse_xlate = sun50i_h6_efuse_xlate,
> +};
> +
> +static const struct of_device_id cpu_opp_match_list[] = {
> +	{ .compatible = "allwinner,sun50i-h6-operating-points",
> +	  .data = &sun50i_h6_cpufreq_data,
> +	},
> +	{}
> +};
> +
>  /**
>   * sun50i_cpufreq_get_efuse() - Determine speed grade from efuse value
> - * @versions: Set to the value parsed from efuse
>   *
> - * Returns 0 if success.
> + * Returns non-negative speed bin index on success, a negative error
> + * value otherwise.
>   */
> -static int sun50i_cpufreq_get_efuse(u32 *versions)
> +static int sun50i_cpufreq_get_efuse(void)
>  {
>  	struct nvmem_cell *speedbin_nvmem;
>  	struct device_node *np;
>  	struct device *cpu_dev;
> -	u32 *speedbin, efuse_value;
> -	size_t len;
> +	const struct of_device_id *match;
> +	const struct sunxi_cpufreq_data *opp_data;
> +	u32 *speedbin;

nit: reverse christmas tree

Other than that,
Reviewed-by: Jernej Skrabec <jernej.skrabec@gmail.com>

Best regards,
Jernej

>  	int ret;
>  
>  	cpu_dev = get_cpu_device(0);
> @@ -48,12 +81,12 @@ static int sun50i_cpufreq_get_efuse(u32 *versions)
>  	if (!np)
>  		return -ENOENT;
>  
> -	ret = of_device_is_compatible(np,
> -				      "allwinner,sun50i-h6-operating-points");
> -	if (!ret) {
> +	match = of_match_node(cpu_opp_match_list, np);
> +	if (!match) {
>  		of_node_put(np);
>  		return -ENOENT;
>  	}
> +	opp_data = match->data;
>  
>  	speedbin_nvmem = of_nvmem_cell_get(np, NULL);
>  	of_node_put(np);
> @@ -61,25 +94,16 @@ static int sun50i_cpufreq_get_efuse(u32 *versions)
>  		return dev_err_probe(cpu_dev, PTR_ERR(speedbin_nvmem),
>  				     "Could not get nvmem cell\n");
>  
> -	speedbin = nvmem_cell_read(speedbin_nvmem, &len);
> +	speedbin = nvmem_cell_read(speedbin_nvmem, NULL);
>  	nvmem_cell_put(speedbin_nvmem);
>  	if (IS_ERR(speedbin))
>  		return PTR_ERR(speedbin);
>  
> -	efuse_value = (*speedbin >> NVMEM_SHIFT) & NVMEM_MASK;
> -
> -	/*
> -	 * We treat unexpected efuse values as if the SoC was from
> -	 * the slowest bin. Expected efuse values are 1-3, slowest
> -	 * to fastest.
> -	 */
> -	if (efuse_value >= 1 && efuse_value <= 3)
> -		*versions = efuse_value - 1;
> -	else
> -		*versions = 0;
> +	ret = opp_data->efuse_xlate(*speedbin);
>  
>  	kfree(speedbin);
> -	return 0;
> +
> +	return ret;
>  };
>  
>  static int sun50i_cpufreq_nvmem_probe(struct platform_device *pdev)
> @@ -87,7 +111,7 @@ static int sun50i_cpufreq_nvmem_probe(struct platform_device *pdev)
>  	int *opp_tokens;
>  	char name[MAX_NAME_LEN];
>  	unsigned int cpu;
> -	u32 speed = 0;
> +	int speed;
>  	int ret;
>  
>  	opp_tokens = kcalloc(num_possible_cpus(), sizeof(*opp_tokens),
> @@ -95,10 +119,10 @@ static int sun50i_cpufreq_nvmem_probe(struct platform_device *pdev)
>  	if (!opp_tokens)
>  		return -ENOMEM;
>  
> -	ret = sun50i_cpufreq_get_efuse(&speed);
> -	if (ret) {
> +	speed = sun50i_cpufreq_get_efuse();
> +	if (speed < 0) {
>  		kfree(opp_tokens);
> -		return ret;
> +		return speed;
>  	}
>  
>  	snprintf(name, MAX_NAME_LEN, "speed%d", speed);
> 





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