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Date:   Mon, 04 Sep 2023 21:28:57 +0200
From:   Martin Botka <martin.botka@somainline.org>
Subject: Re: [PATCH 4/6] cpufreq: sun50i: Add H616 support
To:     Mark Rutland <mark.rutland@arm.com>,
        Lorenzo Pieralisi <lpieralisi@kernel.org>,
        Sudeep Holla <sudeep.holla@arm.com>,
        "Rafael J. Wysocki" <rafael@kernel.org>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Yangtao Li <tiny.windzz@gmail.com>,
        Chen-Yu Tsai <wens@csie.org>,
        Jernej Skrabec <jernej.skrabec@gmail.com>,
        Samuel Holland <samuel@sholland.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>
Cc:     linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        linux-pm@vger.kernel.org, linux-sunxi@lists.linux.dev,
        devicetree@vger.kernel.org,
        Andre Przywara <andre.przywara@arm.com>,
        Alan Ma <tech@biqu3d.com>,
        Luke Harrison <bttuniversity@biqu3d.com>,
        Marijn Suijten <marijn.suijten@somainline.org>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@somainline.org>,
        Konrad Dybcio <konrad.dybcio@somainline.org>,
        Rogerio Goncalves <rogerlz@gmail.com>,
        Martin Botka <martin@biqu3d.com>
Message-Id: <9G7H0S.VAAJCUTOCA353@somainline.org>
In-Reply-To: <20230904-cpufreq-h616-v1-4-b8842e525c43@somainline.org>
References: <20230904-cpufreq-h616-v1-0-b8842e525c43@somainline.org>
        <20230904-cpufreq-h616-v1-4-b8842e525c43@somainline.org>
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On Mon, Sep 4 2023 at 05:57:04 PM +02:00:00, Martin Botka 
<martin.botka@somainline.org> wrote:
> AllWinner H616 SoC has few revisions that support different list
> of uV and frequencies.
> 
> Some revisions have the same NVMEM value and thus we have to check
> the SoC revision from SMCCC to differentiate between them.
> 
> Signed-off-by: Martin Botka <martin.botka@somainline.org>
> ---
>  drivers/cpufreq/sun50i-cpufreq-nvmem.c | 149 
> ++++++++++++++++++++++++++++-----
>  1 file changed, 126 insertions(+), 23 deletions(-)
> 
> diff --git a/drivers/cpufreq/sun50i-cpufreq-nvmem.c 
> b/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> index 4321d7bbe769..19c126fb081e 100644
> --- a/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> +++ b/drivers/cpufreq/sun50i-cpufreq-nvmem.c
> @@ -10,6 +10,7 @@
> 
>  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> 
> +#include <linux/arm-smccc.h>
>  #include <linux/cpu.h>
>  #include <linux/module.h>
>  #include <linux/nvmem-consumer.h>
> @@ -23,20 +24,94 @@
>  #define NVMEM_MASK	0x7
>  #define NVMEM_SHIFT	5
> 
> +struct sunxi_cpufreq_soc_data {
> +	int (*efuse_xlate)(u32 *versions, u32 *efuse, char *name, size_t 
> len);
> +	u8 ver_freq_limit;
> +};
> +
>  static struct platform_device *cpufreq_dt_pdev, *sun50i_cpufreq_pdev;
> 
> +static int sun50i_h616_efuse_xlate(u32 *versions, u32 *efuse, char 
> *name, size_t len)
> +{
> +	int value = 0;
> +	u32 speedgrade = 0;
> +	u32 i;
> +	int ver_bits = arm_smccc_get_soc_id_revision();
> +
> +	if (len > 4) {
> +		pr_err("Invalid nvmem cell length\n");
> +		return -EINVAL;
> +	}
> +
> +	for (i = 0; i < len; i++)
> +		speedgrade |= (efuse[i] << (i * 8));
> +
> +	switch (speedgrade) {
> +	case 0x2000:
> +		value = 0;
> +		break;
> +	case 0x2400:
> +	case 0x7400:
> +	case 0x2c00:
> +	case 0x7c00:
> +		if (ver_bits <= 1) {
> +			/* ic version A/B */
> +			value = 1;
> +		} else {
> +			/* ic version C and later version */
> +			value = 2;
> +		}
> +		break;
> +	case 0x5000:
> +	case 0x5400:
> +	case 0x6000:
> +		value = 3;
> +		break;
> +	case 0x5c00:
> +		value = 4;
> +		break;
> +	case 0x5d00:
> +	default:
> +		value = 0;
> +	}
> +	*versions = (1 << value);
> +	snprintf(name, MAX_NAME_LEN, "speed%d", value);
> +	return 0;
> +}
> +
> +static int sun50i_h6_efuse_xlate(u32 *versions, u32 *efuse, char 
> *name, size_t len)
> +{
> +	int efuse_value = (*efuse >> 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;
> +
> +	snprintf(name, MAX_NAME_LEN, "speed%d", *versions);
> +	return 0;
> +}
> +
>  /**
>   * sun50i_cpufreq_get_efuse() - Determine speed grade from efuse 
> value
> + * @soc_data: Struct containing soc specific data & functions
>   * @versions: Set to the value parsed from efuse
> + * @name: Set to the name of speed
>   *
>   * 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, char *name)
>  {
>  	struct nvmem_cell *speedbin_nvmem;
>  	struct device_node *np;
>  	struct device *cpu_dev;
> -	u32 *speedbin, efuse_value;
> +	u32 *speedbin;
>  	size_t len;
>  	int ret;
> 
> @@ -48,9 +123,9 @@ 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) {
> +	if (of_device_is_compatible(np, 
> "allwinner,sun50i-h6-operating-points")) {
> +	} else if (of_device_is_compatible(np, 
> "allwinner,sun50i-h616-operating-points")) {
> +	} else {
>  		of_node_put(np);
>  		return -ENOENT;
>  	}
> @@ -66,17 +141,9 @@ static int sun50i_cpufreq_get_efuse(u32 *versions)
>  	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 = soc_data->efuse_xlate(versions, speedbin, name, len);
> +	if (ret)
> +		return ret;
> 
>  	kfree(speedbin);
>  	return 0;
> @@ -84,25 +151,30 @@ static int sun50i_cpufreq_get_efuse(u32 
> *versions)
> 
>  static int sun50i_cpufreq_nvmem_probe(struct platform_device *pdev)
>  {
> +	const struct of_device_id *match;
> +	const struct sunxi_cpufreq_soc_data *soc_data;
>  	int *opp_tokens;
>  	char name[MAX_NAME_LEN];
>  	unsigned int cpu;
> -	u32 speed = 0;
> +	u32 version = 0;
>  	int ret;
> 
> +	match = dev_get_platdata(&pdev->dev);
> +	if (!match)
> +		return -EINVAL;
> +	soc_data = match->data;
> +
>  	opp_tokens = kcalloc(num_possible_cpus(), sizeof(*opp_tokens),
>  			     GFP_KERNEL);
>  	if (!opp_tokens)
>  		return -ENOMEM;
> 
> -	ret = sun50i_cpufreq_get_efuse(&speed);
> +	ret = sun50i_cpufreq_get_efuse(match->data, &version, name);
>  	if (ret) {
>  		kfree(opp_tokens);
>  		return ret;
>  	}
> 
> -	snprintf(name, MAX_NAME_LEN, "speed%d", speed);
> -
>  	for_each_possible_cpu(cpu) {
>  		struct device *cpu_dev = get_cpu_device(cpu);
> 
> @@ -117,6 +189,16 @@ static int sun50i_cpufreq_nvmem_probe(struct 
> platform_device *pdev)
>  			pr_err("Failed to set prop name\n");
>  			goto free_opp;
>  		}
> +
> +		if (soc_data->ver_freq_limit) {
> +			opp_tokens[cpu] = dev_pm_opp_set_supported_hw(cpu_dev,
> +								  &version, 1);
> +			if (opp_tokens[cpu] < 0) {
> +				ret = opp_tokens[cpu];
> +				pr_err("Failed to set hw\n");
> +				goto free_opp;
> +			}
> +		}
>  	}
> 
>  	cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1,
> @@ -132,6 +214,8 @@ static int sun50i_cpufreq_nvmem_probe(struct 
> platform_device *pdev)
>  free_opp:
>  	for_each_possible_cpu(cpu)
>  		dev_pm_opp_put_prop_name(opp_tokens[cpu]);
> +		if (soc_data->ver_freq_limit)
> +			dev_pm_opp_put_supported_hw(opp_tokens[cpu]);
>  	kfree(opp_tokens);
> 
>  	return ret;
> @@ -140,12 +224,21 @@ static int sun50i_cpufreq_nvmem_probe(struct 
> platform_device *pdev)
>  static int sun50i_cpufreq_nvmem_remove(struct platform_device *pdev)
>  {
>  	int *opp_tokens = platform_get_drvdata(pdev);
> +	const struct of_device_id *match;
> +	const struct sunxi_cpufreq_soc_data *soc_data;
>  	unsigned int cpu;
> 
> +	match = dev_get_platdata(&pdev->dev);
> +	if (!match)
> +		return -EINVAL;
> +	soc_data = match->data;
> +
>  	platform_device_unregister(cpufreq_dt_pdev);
> 
>  	for_each_possible_cpu(cpu)
>  		dev_pm_opp_put_prop_name(opp_tokens[cpu]);
> +		if (soc_data->ver_freq_limit)
> +			dev_pm_opp_put_supported_hw(opp_tokens[cpu]);
I completely overlooked this issue here. Clang didnt report a warning 
here. I will fix it in both cases in V2 :) Sorry.
> 
>  	kfree(opp_tokens);
> 
> @@ -160,8 +253,18 @@ static struct platform_driver 
> sun50i_cpufreq_driver = {
>  	},
>  };
> 
> +static const struct sunxi_cpufreq_soc_data sun50i_h616_data = {
> +	.efuse_xlate = sun50i_h616_efuse_xlate,
> +	.ver_freq_limit = true,
> +};
> +
> +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 },
> +	{ .compatible = "allwinner,sun50i-h616", .data = &sun50i_h616_data 
> },
>  	{}
>  };
>  MODULE_DEVICE_TABLE(of, sun50i_cpufreq_match_list);
> @@ -197,8 +300,8 @@ static int __init sun50i_cpufreq_init(void)
>  		return ret;
> 
>  	sun50i_cpufreq_pdev =
> -		platform_device_register_simple("sun50i-cpufreq-nvmem",
> -						-1, NULL, 0);
> +		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;
> 
> --
> 2.42.0
>