From: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
The i.MX esdhc has a nonstandard bit layout for the SDHCI_HOST_CONTROL
register. To support 8bit bus width on i.MX populate the platform_bus_width
callback. This is tested on an i.MX25, but should according to the datasheets
work on the other i.MX using this hardware aswell. The i.MX6, while having
a SDHCI_SPEC_300 controller, still uses the same nonstandard register layout.
Signed-off-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx>
---
drivers/mmc/host/sdhci-esdhc-imx.c | 56 ++++++++++++++++++++++++++-
include/linux/platform_data/mmc-esdhc-imx.h | 1 +
2 files changed, 55 insertions(+), 2 deletions(-)
diff --git a/drivers/mmc/host/sdhci-esdhc-imx.c b/drivers/mmc/host/sdhci-esdhc-imx.c
index 24daaf4..f7ee5e6 100644
--- a/drivers/mmc/host/sdhci-esdhc-imx.c
+++ b/drivers/mmc/host/sdhci-esdhc-imx.c
@@ -41,6 +41,13 @@
#define ESDHC_MIX_CTRL_SDHCI_MASK 0xb7
/*
+ * Our interpretation of the SDHCI_HOST_CONTROL register
+ */
+#define ESDHC_CTRL_4BITBUS (0x1 << 1)
+#define ESDHC_CTRL_8BITBUS (0x2 << 1)
+#define ESDHC_CTRL_BUSWIDTH_MASK (0x3 << 1)
+
+/*
* There is an INT DMA ERR mis-match between eSDHC and STD SDHC SPEC:
* Bit25 is used in STD SPEC, and is reserved in fsl eSDHC design,
* but bit28 is used as the INT DMA ERR in fsl eSDHC design.
@@ -294,6 +301,7 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg)
struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
struct pltfm_imx_data *imx_data = pltfm_host->priv;
u32 new_val;
+ u32 mask;
switch (reg) {
case SDHCI_POWER_CONTROL:
@@ -304,7 +312,7 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg)
return;
case SDHCI_HOST_CONTROL:
/* FSL messed up here, so we need to manually compose it. */
- new_val = val & (SDHCI_CTRL_LED | SDHCI_CTRL_4BITBUS);
+ new_val = val & SDHCI_CTRL_LED;
/* ensure the endianness */
new_val |= ESDHC_HOST_CONTROL_LE;
/* bits 8&9 are reserved on mx25 */
@@ -313,7 +321,13 @@ static void esdhc_writeb_le(struct sdhci_host *host, u8 val, int reg)
new_val |= (val & SDHCI_CTRL_DMA_MASK) << 5;
}
- esdhc_clrset_le(host, 0xffff, new_val, reg);
+ /*
+ * Do not touch buswidth bits here. This is done in
+ * esdhc_pltfm_bus_width.
+ */
+ mask = 0xffff & ~ESDHC_CTRL_BUSWIDTH_MASK;
+
+ esdhc_clrset_le(host, mask, new_val, reg);
return;
}
esdhc_clrset_le(host, 0xff, val, reg);
@@ -370,6 +384,28 @@ static unsigned int esdhc_pltfm_get_ro(struct sdhci_host *host)
return -ENOSYS;
}
+static int esdhc_pltfm_bus_width(struct sdhci_host *host, int width)
+{
+ u32 ctrl;
+
+ switch (width) {
+ case MMC_BUS_WIDTH_8:
+ ctrl = ESDHC_CTRL_8BITBUS;
+ break;
+ case MMC_BUS_WIDTH_4:
+ ctrl = ESDHC_CTRL_4BITBUS;
+ break;
+ default:
+ ctrl = 0;
+ break;
+ }
+
+ esdhc_clrset_le(host, ESDHC_CTRL_BUSWIDTH_MASK, ctrl,
+ SDHCI_HOST_CONTROL);
+
+ return 0;
+}
+
static struct sdhci_ops sdhci_esdhc_ops = {
.read_l = esdhc_readl_le,
.read_w = esdhc_readw_le,
@@ -380,6 +416,7 @@ static struct sdhci_ops sdhci_esdhc_ops = {
.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,
};
static struct sdhci_pltfm_data sdhci_esdhc_imx_pdata = {
@@ -417,6 +454,8 @@ sdhci_esdhc_imx_probe_dt(struct platform_device *pdev,
if (gpio_is_valid(boarddata->wp_gpio))
boarddata->wp_type = ESDHC_WP_GPIO;
+ of_property_read_u32(np, "bus-width", &boarddata->max_bus_width);
+
return 0;
}
#else
@@ -548,6 +587,19 @@ static int sdhci_esdhc_imx_probe(struct platform_device *pdev)
break;
}
+ switch (boarddata->max_bus_width) {
+ case 8:
+ host->mmc->caps |= MMC_CAP_8_BIT_DATA | MMC_CAP_4_BIT_DATA;
+ break;
+ case 4:
+ host->mmc->caps |= MMC_CAP_4_BIT_DATA;
+ break;
+ case 1:
+ default:
+ host->quirks |= SDHCI_QUIRK_FORCE_1_BIT_DATA;
+ break;
+ }
+
err = sdhci_add_host(host);
if (err)
goto disable_clk;
diff --git a/include/linux/platform_data/mmc-esdhc-imx.h b/include/linux/platform_data/mmc-esdhc-imx.h
index aaf9748..b4a0521 100644
--- a/include/linux/platform_data/mmc-esdhc-imx.h
+++ b/include/linux/platform_data/mmc-esdhc-imx.h
@@ -39,5 +39,6 @@ struct esdhc_platform_data {
unsigned int cd_gpio;
enum wp_types wp_type;
enum cd_types cd_type;
+ int max_bus_width;
};
#endif /* __ASM_ARCH_IMX_ESDHC_H */
--
1.7.9.5
--
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