mmc: sdhci-s3c: Choose sdhci_ops based on variant

The difference between old S3C64xx and newer Exynos4 SDHCI controller
variants is in clock handling (the "no_divider" field in drvdata).
Choose the proper sdhci_ops based on the variant instead of patching
ops in probe, if Exynos4 is used.

This allows making struct sdhci_ops const for code safety and probably
opens further options in the future, as the dynamic pointer ops table is
not anymore that dynamic.
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Link: https://lore.kernel.org/r/20240414-mmc-const-sdhci-ops-v2-5-262f81faadac@kernel.orgSigned-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/mmc/host/sdhci-s3c.c

@@ -130,14 +130,16 @@ struct sdhci_s3c {
  * struct sdhci_s3c_drv_data - S3C SDHCI platform specific driver data
  * @sdhci_quirks: sdhci host specific quirks.
  * @no_divider: no or non-standard internal clock divider.
+ * @ops: sdhci_ops to use for this variant
  *
  * Specifies platform specific configuration of sdhci controller.
  * Note: A structure for driver specific platform data is used for future
  * expansion of its usage.
  */
 struct sdhci_s3c_drv_data {
-	unsigned int	sdhci_quirks;
-	bool		no_divider;
+	unsigned int		sdhci_quirks;
+	bool			no_divider;
+	const struct sdhci_ops	*ops;
 };
 
 static inline struct sdhci_s3c *to_s3c(struct sdhci_host *host)
@@ -412,7 +414,7 @@ static void sdhci_cmu_set_clock(struct sdhci_host *host, unsigned int clock)
 	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
 }
 
-static struct sdhci_ops sdhci_s3c_ops = {
+static const struct sdhci_ops sdhci_s3c_ops_s3c6410 = {
 	.get_max_clock		= sdhci_s3c_get_max_clk,
 	.set_clock		= sdhci_s3c_set_clock,
 	.get_min_clock		= sdhci_s3c_get_min_clock,
@@ -421,6 +423,15 @@ static struct sdhci_ops sdhci_s3c_ops = {
 	.set_uhs_signaling	= sdhci_set_uhs_signaling,
 };
 
+static const struct sdhci_ops sdhci_s3c_ops_exynos4 __maybe_unused = {
+	.get_max_clock		= sdhci_cmu_get_max_clock,
+	.set_clock		= sdhci_cmu_set_clock,
+	.get_min_clock		= sdhci_cmu_get_min_clock,
+	.set_bus_width		= sdhci_set_bus_width,
+	.reset			= sdhci_reset,
+	.set_uhs_signaling	= sdhci_set_uhs_signaling,
+};
+
 #ifdef CONFIG_OF
 static int sdhci_s3c_parse_dt(struct device *dev,
 		struct sdhci_host *host, struct s3c_sdhci_platdata *pdata)
@@ -560,7 +571,7 @@ static int sdhci_s3c_probe(struct platform_device *pdev)
 		pdata->cfg_gpio(pdev, pdata->max_width);
 
 	host->hw_name = "samsung-hsmmc";
-	host->ops = &sdhci_s3c_ops;
+	host->ops = &sdhci_s3c_ops_s3c6410;
 	host->quirks = 0;
 	host->quirks2 = 0;
 	host->irq = irq;
@@ -570,6 +581,7 @@ static int sdhci_s3c_probe(struct platform_device *pdev)
 	host->quirks |= SDHCI_QUIRK_NO_HISPD_BIT;
 	if (drv_data) {
 		host->quirks |= drv_data->sdhci_quirks;
+		host->ops = drv_data->ops;
 		sc->no_divider = drv_data->no_divider;
 	}
 
@@ -617,16 +629,6 @@ static int sdhci_s3c_probe(struct platform_device *pdev)
 	/* HSMMC on Samsung SoCs uses SDCLK as timeout clock */
 	host->quirks |= SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK;
 
-	/*
-	 * If controller does not have internal clock divider,
-	 * we can use overriding functions instead of default.
-	 */
-	if (sc->no_divider) {
-		sdhci_s3c_ops.set_clock = sdhci_cmu_set_clock;
-		sdhci_s3c_ops.get_min_clock = sdhci_cmu_get_min_clock;
-		sdhci_s3c_ops.get_max_clock = sdhci_cmu_get_max_clock;
-	}
-
 	/* It supports additional host capabilities if needed */
 	if (pdata->host_caps)
 		host->mmc->caps |= pdata->host_caps;
@@ -758,6 +760,7 @@ MODULE_DEVICE_TABLE(platform, sdhci_s3c_driver_ids);
 #ifdef CONFIG_OF
 static const struct sdhci_s3c_drv_data exynos4_sdhci_drv_data = {
 	.no_divider = true,
+	.ops = &sdhci_s3c_ops_exynos4,
 };
 
 static const struct of_device_id sdhci_s3c_dt_match[] = {