This patch adds support of connecting an MMC media using an 8-bit
bus width connection to Freescale's P2020 H/W SDHC controller. During
the probe function, it detects if the processor is P2020 (by looking
at device tree) and if so, it adds the MMC_CAP_8_BIT_DATA to the MMC
caps
Signed-off-by: Oded Gabbay <ogabbay@xxxxxxxxxxxxxxx>
---
drivers/mmc/host/sdhci-esdhc.h | 7 ++++++
drivers/mmc/host/sdhci-of-esdhc.c | 49 ++++++++++++++++++++++++++++++++++++++-
2 files changed, 55 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/host/sdhci-esdhc.h b/drivers/mmc/host/sdhci-esdhc.h
index d25f9ab..6f9a018 100644
--- a/drivers/mmc/host/sdhci-esdhc.h
+++ b/drivers/mmc/host/sdhci-esdhc.h
@@ -36,6 +36,13 @@
/* pltfm-specific */
#define ESDHC_HOST_CONTROL_LE 0x20
+/*
+ * P2020 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)
+
/* OF-specific */
#define ESDHC_DMA_SYSCTL 0x40c
#define ESDHC_DMA_SNOOP 0x00000040
diff --git a/drivers/mmc/host/sdhci-of-esdhc.c b/drivers/mmc/host/sdhci-of-esdhc.c
index f8eb1fb..6f433b8 100644
--- a/drivers/mmc/host/sdhci-of-esdhc.c
+++ b/drivers/mmc/host/sdhci-of-esdhc.c
@@ -13,6 +13,7 @@
* your option) any later version.
*/
+#include <linux/err.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/delay.h>
@@ -143,6 +144,31 @@ static void esdhc_of_resume(struct sdhci_host *host)
}
#endif
+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;
+ }
+
+ clrsetbits_be32(host->ioaddr + SDHCI_HOST_CONTROL,
+ ESDHC_CTRL_BUSWIDTH_MASK, ctrl);
+
+ return 0;
+}
+
+
static struct sdhci_ops sdhci_esdhc_ops = {
.read_l = sdhci_be32bs_readl,
.read_w = esdhc_readw,
@@ -158,6 +184,7 @@ static struct sdhci_ops sdhci_esdhc_ops = {
.platform_suspend = esdhc_of_suspend,
.platform_resume = esdhc_of_resume,
#endif
+ .platform_8bit_width = esdhc_pltfm_bus_width
};
static struct sdhci_pltfm_data sdhci_esdhc_pdata = {
@@ -169,7 +196,27 @@ static struct sdhci_pltfm_data sdhci_esdhc_pdata = {
static int __devinit sdhci_esdhc_probe(struct platform_device *pdev)
{
- return sdhci_pltfm_register(pdev, &sdhci_esdhc_pdata);
+ struct sdhci_host *host;
+ struct device_node *np;
+ int ret = 0;
+
+ host = sdhci_pltfm_init(pdev, &sdhci_esdhc_pdata);
+ if (IS_ERR(host))
+ return PTR_ERR(host);
+
+ sdhci_get_of_property(pdev);
+
+ np = pdev->dev.of_node;
+ if (of_device_is_compatible(np, "fsl,p2020-esdhc")) {
+ /* P2020 has capability of 8 bit bus width */
+ host->mmc->caps |= MMC_CAP_8_BIT_DATA;
+ }
+
+ ret = sdhci_add_host(host);
+ if (ret)
+ sdhci_pltfm_free(pdev);
+
+ return ret;
}
static int __devexit sdhci_esdhc_remove(struct platform_device *pdev)
--
1.7.11.7
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