mmc: zynq: Add fdt max-frequency support

The maximum supported peripheral clock frequency of the zynq depends on
the IO routing. The MIO and EMIO support a maximum frequency of 50 MHz
respectively 25 MHz. Use the max-frequency value of the device tree to
determine the maximal supported peripheral clock frequency.

Signed-off-by: Stefan Herbrechtsmeier <stefan.herbrechtsmeier@weidmueller.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Jaehoon Chung <jh80.chung@samsung.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>

diff --git a/drivers/mmc/zynq_sdhci.c b/drivers/mmc/zynq_sdhci.c
index c73a4d3..28cedf0 100644 (file)
--- a/drivers/mmc/zynq_sdhci.c
+++ b/drivers/mmc/zynq_sdhci.c
@@ -14,6 +14,8 @@
 #include <malloc.h>
 #include <sdhci.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 #ifndef CONFIG_ZYNQ_SDHCI_MIN_FREQ
 # define CONFIG_ZYNQ_SDHCI_MIN_FREQ    0
 #endif
@@ -21,6 +23,7 @@
 struct arasan_sdhci_plat {
        struct mmc_config cfg;
        struct mmc mmc;
+       unsigned int f_max;
 };
 
 static int arasan_sdhci_probe(struct udevice *dev)
@@ -60,7 +63,7 @@ static int arasan_sdhci_probe(struct udevice *dev)
 
        host->max_clk = clock;
 
-       ret = sdhci_setup_cfg(&plat->cfg, host, CONFIG_ZYNQ_SDHCI_MAX_FREQ,
+       ret = sdhci_setup_cfg(&plat->cfg, host, plat->f_max,
                              CONFIG_ZYNQ_SDHCI_MIN_FREQ);
        host->mmc = &plat->mmc;
        if (ret)
@@ -74,11 +77,15 @@ static int arasan_sdhci_probe(struct udevice *dev)
 
 static int arasan_sdhci_ofdata_to_platdata(struct udevice *dev)
 {
+       struct arasan_sdhci_plat *plat = dev_get_platdata(dev);
        struct sdhci_host *host = dev_get_priv(dev);
 
        host->name = dev->name;
        host->ioaddr = (void *)dev_get_addr(dev);
 
+       plat->f_max = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
+                               "max-frequency", CONFIG_ZYNQ_SDHCI_MAX_FREQ);
+
        return 0;
 }