Hello,
On 12/7/20 8:37 PM, Shuosheng Huang wrote:
> It's better to use efuse_xlate to extract the differentiated part
> regarding different SoC.
>
> Signed-off-by: Shuosheng Huang <huangshuosh...@allwinnertech.com>
> ---
> drivers/cpufreq/sun50i-cpufreq-nvmem.c | 72 +++++++++++++++++---------
> 1 file changed, 48 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> b/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> index 9907a165135b..da23d581a4b4 100644
> --- a/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> +++ b/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> @@ -22,21 +22,52 @@
> #define NVMEM_MASK 0x7
> #define NVMEM_SHIFT 5
You should remove these definitions now that you added the ones below.
>
> +#define SUN50I_H6_NVMEM_MASK 0x7
> +#define SUN50I_H6_NVMEM_SHIFT 5
> +
> +struct sunxi_cpufreq_soc_data {
> + u32 (*efuse_xlate)(void *efuse);
> +};
> +
> static struct platform_device *cpufreq_dt_pdev, *sun50i_cpufreq_pdev;
>
> +static u32 sun50i_h6_efuse_xlate(struct nvmem_cell *speedbin_nvmem)
> +{
> + size_t len;
> + u32 *speedbin;
> + u32 efuse_value;
> +
> + speedbin = nvmem_cell_read(speedbin_nvmem, &len);
> + if (IS_ERR(speedbin))
> + return PTR_ERR(speedbin);
You're trying to return a negative value for an error here, but the
return type is unsigned.
> +
> + efuse_value = (*(u32 *)speedbin >> SUN50I_H6_NVMEM_SHIFT) &
> + SUN50I_H6_NVMEM_MASK;
> + kfree(speedbin);
> + /*
> + * 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;
> +}
> +
> /**
> * sun50i_cpufreq_get_efuse() - Determine speed grade from efuse value
> + * @soc_data: pointer to sunxi_cpufreq_soc_data context
> * @versions: Set to the value parsed from efuse
> *
> * Returns 0 if success.
> */
> -static int sun50i_cpufreq_get_efuse(u32 *versions)
> +static int sun50i_cpufreq_get_efuse(const struct sunxi_cpufreq_soc_data
> *soc_data,
> + u32 *versions)
> {
> struct nvmem_cell *speedbin_nvmem;
> struct device_node *np;
> struct device *cpu_dev;
> - u32 *speedbin, efuse_value;
> - size_t len;
> int ret;
>
> cpu_dev = get_cpu_device(0);
> @@ -63,41 +94,31 @@ static int sun50i_cpufreq_get_efuse(u32 *versions)
> return PTR_ERR(speedbin_nvmem);
> }
>
> - speedbin = nvmem_cell_read(speedbin_nvmem, &len);
> + *versions = soc_data->efuse_xlate(speedbin_nvmem);
> 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;
>
> - kfree(speedbin);
> return 0;
If *versions is negative, you need to pass that error back to the caller.
> };
>
> static int sun50i_cpufreq_nvmem_probe(struct platform_device *pdev)
> {
> + const struct of_device_id *match;
> struct opp_table **opp_tables;
> char name[MAX_NAME_LEN];
> unsigned int cpu;
> u32 speed = 0;
> int ret;
>
> + match = dev_get_platdata(&pdev->dev);
> + if (!match)
> + return -EINVAL;
> +
> opp_tables = kcalloc(num_possible_cpus(), sizeof(*opp_tables),
> GFP_KERNEL);
> if (!opp_tables)
> return -ENOMEM;
>
> - ret = sun50i_cpufreq_get_efuse(&speed);
> + ret = sun50i_cpufreq_get_efuse(match->data, &speed);
> if (ret)
> return ret;
Since we've already decoupled the speed grade from the nvmem value, why
not make this:
int speed;
...
speed = sun50i_cpufreq_get_efuse(match->data);
if (speed < 0)
return speed;
And have sun50i_cpufreq_get_efuse return the value from efuse_xlate
without all the pointer indirection.
And this is a separate bug in the existing code, but it leaks opp_tables
if sun50i_cpufreq_get_efuse fails. That could be fixed by moving the
call to sun50i_cpufreq_get_efuse up.
Cheers,
Samuel
>
> @@ -163,8 +184,12 @@ static struct platform_driver sun50i_cpufreq_driver = {
> },
> };
>
> +static const struct sunxi_cpufreq_soc_data sun50i_h6_data = {
> + .efuse_xlate = sun50i_h6_efuse_xlate,
> +};
> +
> static const struct of_device_id sun50i_cpufreq_match_list[] = {
> - { .compatible = "allwinner,sun50i-h6" },
> + { .compatible = "allwinner,sun50i-h6", .data = &sun50i_h6_data },
> {}
> };
>
> @@ -198,9 +223,8 @@ static int __init sun50i_cpufreq_init(void)
> if (unlikely(ret < 0))
> return ret;
>
> - sun50i_cpufreq_pdev =
> - platform_device_register_simple("sun50i-cpufreq-nvmem",
> - -1, NULL, 0);
> + sun50i_cpufreq_pdev = platform_device_register_data(NULL,
> + "sun50i-cpufreq-nvmem", -1, match, sizeof(*match));
> ret = PTR_ERR_OR_ZERO(sun50i_cpufreq_pdev);
> if (ret == 0)
> return 0;
>
