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 <[email protected]> --- 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 -- To unsubscribe from this list: send the line "unsubscribe linux-mmc" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
