linux-kernel - [RFC PATCH v3 1/3] cpufreq: sun50i: Refactor speed bin decoding

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Message-Id: <20231222111407.104270-2-fusibrandon13@gmail.com>
Date: Fri, 22 Dec 2023 12:14:05 +0100
From: Brandon Cheo Fusi <fusibrandon13@...il.com>
To: Andre Przywara <andre.przywara@....com>,
	Rob Herring <robh+dt@...nel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
	Conor Dooley <conor+dt@...nel.org>,
	Paul Walmsley <paul.walmsley@...ive.com>,
	Palmer Dabbelt <palmer@...belt.com>,
	Albert Ou <aou@...s.berkeley.edu>,
	Chen-Yu Tsai <wens@...e.org>,
	Jernej Skrabec <jernej.skrabec@...il.com>,
	Samuel Holland <samuel@...lland.org>,
	Yangtao Li <tiny.windzz@...il.com>,
	"Rafael J . Wysocki" <rafael@...nel.org>,
	Viresh Kumar <viresh.kumar@...aro.org>,
	Stephen Rothwell <sfr@...b.auug.org.au>
Cc: devicetree@...r.kernel.org,
	linux-riscv@...ts.infradead.org,
	linux-arm-kernel@...ts.infradead.org,
	linux-sunxi@...ts.linux.dev,
	linux-kernel@...r.kernel.org,
	linux-pm@...r.kernel.org,
	Brandon Cheo Fusi <fusibrandon13@...il.com>
Subject: [RFC PATCH v3 1/3] cpufreq: sun50i: Refactor speed bin decoding

Make converting the speed bin value into a speed grade generic
and determined by a platform specific callback.

Signed-off-by: Brandon Cheo Fusi <fusibrandon13@...il.com>
---
 drivers/cpufreq/sun50i-cpufreq-nvmem.c | 58 ++++++++++++++++++--------
 1 file changed, 40 insertions(+), 18 deletions(-)

diff --git a/drivers/cpufreq/sun50i-cpufreq-nvmem.c b/drivers/cpufreq/sun50i-cpufreq-nvmem.c
index 32a9c88f8..e8c2a1dc3 100644
--- a/drivers/cpufreq/sun50i-cpufreq-nvmem.c
+++ b/drivers/cpufreq/sun50i-cpufreq-nvmem.c
@@ -25,6 +25,38 @@
 
 static struct platform_device *cpufreq_dt_pdev, *sun50i_cpufreq_pdev;
 
+struct sunxi_cpufreq_data {
+	u32 (*efuse_xlate)(u32 speedbin);
+};
+
+static u32 sun50i_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_cpufreq_data = {
+	.efuse_xlate = sun50i_efuse_xlate,
+};
+
+static const struct of_device_id cpu_opp_match_list[] = {
+	{ .compatible = "allwinner,sun50i-h6-operating-points",
+	  .data = &sun50i_cpufreq_data,
+	},
+	{}
+};
+
 /**
  * sun50i_cpufreq_get_efuse() - Determine speed grade from efuse value
  * @versions: Set to the value parsed from efuse
@@ -36,9 +68,9 @@ static int sun50i_cpufreq_get_efuse(u32 *versions)
 	struct nvmem_cell *speedbin_nvmem;
 	struct device_node *np;
 	struct device *cpu_dev;
-	u32 *speedbin, efuse_value;
-	size_t len;
-	int ret;
+	const struct of_device_id *match;
+	const struct sunxi_cpufreq_data *opp_data;
+	u32 *speedbin;
 
 	cpu_dev = get_cpu_device(0);
 	if (!cpu_dev)
@@ -48,12 +80,12 @@ 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);
@@ -61,22 +93,12 @@ 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;
+	*versions = opp_data->efuse_xlate(*speedbin);
 
 	kfree(speedbin);
 	return 0;
-- 
2.30.2