mmc: sdhci: Distinguish between base clock and maximum peripheral frequency

The sdhci controller assumes that the base clock frequency is fully supported by
the peripheral and doesn't support hardware limitations. The Linux kernel
distinguishes between base clock (max_clk) of the host controller and maximum
frequency (f_max) of the card interface. Use the same differentiation and allow
the platform to constrain the peripheral interface.

Signed-off-by: Stefan Herbrechtsmeier <stefan.herbrechtsmeier@weidmueller.com>

1 files changed, 18 insertions, 16 deletions

diff --git a/drivers/mmc/sdhci.c b/drivers/mmc/sdhci.c
index 5b404ff..84e0581 100644
--- a/drivers/mmc/sdhci.c
+++ b/drivers/mmc/sdhci.c
@@ -325,7 +325,7 @@ static int sdhci_set_clock(struct mmc *mmc, unsigned int clock)
 		 */
 		if (host->clk_mul) {
 			for (div = 1; div <= 1024; div++) {
-				if ((mmc->cfg->f_max * host->clk_mul / div)
+				if ((host->max_clk * host->clk_mul / div)
 					<= clock)
 					break;
 			}
@@ -338,13 +338,13 @@ static int sdhci_set_clock(struct mmc *mmc, unsigned int clock)
 			div--;
 		} else {
 			/* Version 3.00 divisors must be a multiple of 2. */
-			if (mmc->cfg->f_max <= clock) {
+			if (host->max_clk <= clock) {
 				div = 1;
 			} else {
 				for (div = 2;
 				     div < SDHCI_MAX_DIV_SPEC_300;
 				     div += 2) {
-					if ((mmc->cfg->f_max / div) <= clock)
+					if ((host->max_clk / div) <= clock)
 						break;
 				}
 			}
@@ -353,7 +353,7 @@ static int sdhci_set_clock(struct mmc *mmc, unsigned int clock)
 	} else {
 		/* Version 2.00 divisors must be a power of 2. */
 		for (div = 1; div < SDHCI_MAX_DIV_SPEC_200; div *= 2) {
-			if ((mmc->cfg->f_max / div) <= clock)
+			if ((host->max_clk / div) <= clock)
 				break;
 		}
 		div >>= 1;
@@ -513,7 +513,7 @@ static const struct mmc_ops sdhci_ops = {
 #endif
 
 int sdhci_setup_cfg(struct mmc_config *cfg, struct sdhci_host *host,
-		u32 max_clk, u32 min_clk)
+		u32 f_max, u32 f_min)
 {
 	u32 caps, caps_1;
 
@@ -536,24 +536,26 @@ int sdhci_setup_cfg(struct mmc_config *cfg, struct sdhci_host *host,
 #ifndef CONFIG_DM_MMC_OPS
 	cfg->ops = &sdhci_ops;
 #endif
-	if (max_clk)
-		cfg->f_max = max_clk;
-	else {
+	if (host->max_clk == 0) {
 		if (SDHCI_GET_VERSION(host) >= SDHCI_SPEC_300)
-			cfg->f_max = (caps & SDHCI_CLOCK_V3_BASE_MASK) >>
+			host->max_clk = (caps & SDHCI_CLOCK_V3_BASE_MASK) >>
 				SDHCI_CLOCK_BASE_SHIFT;
 		else
-			cfg->f_max = (caps & SDHCI_CLOCK_BASE_MASK) >>
+			host->max_clk = (caps & SDHCI_CLOCK_BASE_MASK) >>
 				SDHCI_CLOCK_BASE_SHIFT;
-		cfg->f_max *= 1000000;
+		host->max_clk *= 1000000;
 	}
-	if (cfg->f_max == 0) {
+	if (host->max_clk == 0) {
 		printf("%s: Hardware doesn't specify base clock frequency\n",
 		       __func__);
 		return -EINVAL;
 	}
-	if (min_clk)
-		cfg->f_min = min_clk;
+	if (f_max && (f_max < host->max_clk))
+		cfg->f_max = f_max;
+	else
+		cfg->f_max = host->max_clk;
+	if (f_min)
+		cfg->f_min = f_min;
 	else {
 		if (SDHCI_GET_VERSION(host) >= SDHCI_SPEC_300)
 			cfg->f_min = cfg->f_max / SDHCI_MAX_DIV_SPEC_300;
@@ -598,11 +600,11 @@ int sdhci_bind(struct udevice *dev, struct mmc *mmc, struct mmc_config *cfg)
 	return mmc_bind(dev, mmc, cfg);
 }
 #else
-int add_sdhci(struct sdhci_host *host, u32 max_clk, u32 min_clk)
+int add_sdhci(struct sdhci_host *host, u32 f_max, u32 f_min)
 {
 	int ret;
 
-	ret = sdhci_setup_cfg(&host->cfg, host, max_clk, min_clk);
+	ret = sdhci_setup_cfg(&host->cfg, host, f_max, f_min);
 	if (ret)
 		return ret;