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path: root/drivers/mmc/host/sdhci-s3c.c
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Diffstat (limited to 'drivers/mmc/host/sdhci-s3c.c')
-rw-r--r--drivers/mmc/host/sdhci-s3c.c66
1 files changed, 66 insertions, 0 deletions
diff --git a/drivers/mmc/host/sdhci-s3c.c b/drivers/mmc/host/sdhci-s3c.c
index aacb862ecc8a..17203586305c 100644
--- a/drivers/mmc/host/sdhci-s3c.c
+++ b/drivers/mmc/host/sdhci-s3c.c
@@ -130,6 +130,15 @@ static unsigned int sdhci_s3c_consider_clock(struct sdhci_s3c *ourhost,
if (!clksrc)
return UINT_MAX;
+ /*
+ * Clock divider's step is different as 1 from that of host controller
+ * when 'clk_type' is S3C_SDHCI_CLK_DIV_EXTERNAL.
+ */
+ if (ourhost->pdata->clk_type) {
+ rate = clk_round_rate(clksrc, wanted);
+ return wanted - rate;
+ }
+
rate = clk_get_rate(clksrc);
for (div = 1; div < 256; div *= 2) {
@@ -232,6 +241,42 @@ static unsigned int sdhci_s3c_get_min_clock(struct sdhci_host *host)
return min;
}
+/* sdhci_cmu_get_max_clk - callback to get maximum clock frequency.*/
+static unsigned int sdhci_cmu_get_max_clock(struct sdhci_host *host)
+{
+ struct sdhci_s3c *ourhost = to_s3c(host);
+
+ return clk_round_rate(ourhost->clk_bus[ourhost->cur_clk], UINT_MAX);
+}
+
+/* sdhci_cmu_get_min_clock - callback to get minimal supported clock value. */
+static unsigned int sdhci_cmu_get_min_clock(struct sdhci_host *host)
+{
+ struct sdhci_s3c *ourhost = to_s3c(host);
+
+ /*
+ * initial clock can be in the frequency range of
+ * 100KHz-400KHz, so we set it as max value.
+ */
+ return clk_round_rate(ourhost->clk_bus[ourhost->cur_clk], 400000);
+}
+
+/* sdhci_cmu_set_clock - callback on clock change.*/
+static void sdhci_cmu_set_clock(struct sdhci_host *host, unsigned int clock)
+{
+ struct sdhci_s3c *ourhost = to_s3c(host);
+
+ /* don't bother if the clock is going off */
+ if (clock == 0)
+ return;
+
+ sdhci_s3c_set_clock(host, clock);
+
+ clk_set_rate(ourhost->clk_bus[ourhost->cur_clk], clock);
+
+ host->clock = clock;
+}
+
static struct sdhci_ops sdhci_s3c_ops = {
.get_max_clock = sdhci_s3c_get_max_clk,
.set_clock = sdhci_s3c_set_clock,
@@ -361,6 +406,13 @@ static int __devinit sdhci_s3c_probe(struct platform_device *pdev)
clks++;
sc->clk_bus[ptr] = clk;
+
+ /*
+ * save current clock index to know which clock bus
+ * is used later in overriding functions.
+ */
+ sc->cur_clk = ptr;
+
clk_enable(clk);
dev_info(dev, "clock source %d: %s (%ld Hz)\n",
@@ -427,6 +479,20 @@ static int __devinit 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 (pdata->clk_type) {
+ 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;
+
ret = sdhci_add_host(host);
if (ret) {
dev_err(dev, "sdhci_add_host() failed\n");