In order to make it possible to reduce the SD bus frequency, parse the
optional "max-frequency" attribute as documented in
devicetree/bindings/mmc/mmc.txt
Signed-off-by: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci-esdhc-imx.c | 18 +++++++++++++++++-
include/linux/platform_data/mmc-esdhc-imx.h | 1 +
2 files changed, 18 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 8f99c3c..ac36593 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -384,6 +384,20 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg)
}
}
+static unsigned int esdhc_pltfm_get_max_clock(struct sdhci_host *host)
+{
+ struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
+ struct pltfm_imx_data *imx_data = pltfm_host->priv;
+ struct esdhc_platform_data *boarddata = &imx_data->boarddata;
+
+ u32 f_host = clk_get_rate(pltfm_host->clk);
+
+ if (boarddata->f_max && (boarddata->f_max < f_host))
+ return boarddata->f_max;
+ else
+ return f_host;
+}
+
static unsigned int esdhc_pltfm_get_min_clock(struct sdhci_host *host)
{
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
@@ -447,7 +461,7 @@ static const struct sdhci_ops sdhci_esdhc_ops = {
.write_w = esdhc_writew_le,
.write_b = esdhc_writeb_le,
.set_clock = esdhc_pltfm_set_clock,
- .get_max_clock = sdhci_pltfm_clk_get_max_clock,
+ .get_max_clock = esdhc_pltfm_get_max_clock,
.get_min_clock = esdhc_pltfm_get_min_clock,
.get_ro = esdhc_pltfm_get_ro,
.platform_bus_width = esdhc_pltfm_bus_width,
@@ -490,6 +504,8 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev,
of_property_read_u32(np, "bus-width", &boarddata->max_bus_width);
+ of_property_read_u32(np, "max-frequency", &boarddata->f_max);
+
return 0;
}
#else
diff --git a/include/linux/platform_data/mmc-esdhc-imx.h b/include/linux/platform_data/mmc-esdhc-imx.h
index b4a0521..d44912d 100644
--- a/include/linux/platform_data/mmc-esdhc-imx.h
+++ b/include/linux/platform_data/mmc-esdhc-imx.h
@@ -40,5 +40,6 @@ struct esdhc_platform_data {
enum wp_types wp_type;
enum cd_types cd_type;
int max_bus_width;
+ unsigned int f_max;
};
#endif /* __ASM_ARCH_IMX_ESDHC_H */
--
1.8.2.rc2
--
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