[050/177] sdhci-s3c: add support for the non standard minimal clock value

Commit Message

Andrew Morton Aug. 11, 2010, 1:01 a.m. UTC

None

Patch

diff -puN drivers/mmc/host/sdhci-s3c.c~sdhci-s3c-add-support-for-the-non-standard-minimal-clock-value drivers/mmc/host/sdhci-s3c.c
--- a/drivers/mmc/host/sdhci-s3c.c~sdhci-s3c-add-support-for-the-non-standard-minimal-clock-value
+++ a/drivers/mmc/host/sdhci-s3c.c
@@ -203,9 +203,36 @@  static void sdhci_s3c_set_clock(struct s
 	}
 }
 
+/**
+ * sdhci_s3c_get_min_clock - callback to get minimal supported clock value
+ * @host: The SDHCI host being queried
+ *
+ * To init mmc host properly a minimal clock value is needed. For high system
+ * bus clock's values the standard formula gives values out of allowed range.
+ * The clock still can be set to lower values, if clock source other then
+ * system bus is selected.
+*/
+static unsigned int sdhci_s3c_get_min_clock(struct sdhci_host *host)
+{
+	struct sdhci_s3c *ourhost = to_s3c(host);
+	unsigned int delta, min = UINT_MAX;
+	int src;
+
+	for (src = 0; src < MAX_BUS_CLK; src++) {
+		delta = sdhci_s3c_consider_clock(ourhost, src, 0);
+		if (delta == UINT_MAX)
+			continue;
+		/* delta is a negative value in this case */
+		if (-delta < min)
+			min = -delta;
+	}
+	return min;
+}
+
 static struct sdhci_ops sdhci_s3c_ops = {
 	.get_max_clock		= sdhci_s3c_get_max_clk,
 	.set_clock		= sdhci_s3c_set_clock,
+	.get_min_clock		= sdhci_s3c_get_min_clock,
 };
 
 static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
diff -puN drivers/mmc/host/sdhci.c~sdhci-s3c-add-support-for-the-non-standard-minimal-clock-value drivers/mmc/host/sdhci.c
--- a/drivers/mmc/host/sdhci.c~sdhci-s3c-add-support-for-the-non-standard-minimal-clock-value
+++ a/drivers/mmc/host/sdhci.c
@@ -1791,8 +1791,7 @@  int sdhci_add_host(struct sdhci_host *ho
 	 * Set host parameters.
 	 */
 	mmc->ops = &sdhci_ops;
-	if (host->quirks & SDHCI_QUIRK_NONSTANDARD_CLOCK &&
-			host->ops->get_min_clock)
+	if (host->ops->get_min_clock)
 		mmc->f_min = host->ops->get_min_clock(host);
 	else
 		mmc->f_min = host->max_clk / 256;