ARM: OMAP: Enable 8-bit eMMC access for OMAP4/5/DRA7xx
Enable 8-bit host capability for HSMMC2 and/or HSMMC3. CONFIG_HSMMC2_8BIT
(for OMAP4/5/DRA7xx) and/or CONFIG_HSMMC3_8BIT (for DRA7xx only) must be
defined in the board header if an 8-bit eMMC device is connected to the
corresponding port.
Fix the "No status update" error that appeared for eMMC devices by
inserting a 20 us delay between writing arguments and command. This
solution has been proposed by Michael Cashwell <mboards@prograde.net>.
A minor cosmetic fix in a comment as well.
Signed-off-by: Lubomir Popov <lpopov@mm-sol.com>
diff --git a/drivers/mmc/omap_hsmmc.c b/drivers/mmc/omap_hsmmc.c
index 0e36bf9..d3a8b53 100644
--- a/drivers/mmc/omap_hsmmc.c
+++ b/drivers/mmc/omap_hsmmc.c
@@ -400,6 +400,7 @@
}
writel(cmd->cmdarg, &mmc_base->arg);
+ udelay(20); /* To fix "No status update" error on eMMC */
writel((cmd->cmdidx << 24) | flags, &mmc_base->cmd);
start = get_timer(0);
@@ -504,7 +505,7 @@
unsigned int count;
/*
- * Start Polled Read
+ * Start Polled Write
*/
count = (size > MMCSD_SECTOR_SIZE) ? MMCSD_SECTOR_SIZE : size;
count /= 4;
@@ -610,6 +611,8 @@
{
struct mmc *mmc = &hsmmc_dev[dev_index];
struct omap_hsmmc_data *priv_data = &hsmmc_dev_data[dev_index];
+ uint host_caps_val = MMC_MODE_4BIT | MMC_MODE_HS_52MHz | MMC_MODE_HS |
+ MMC_MODE_HC;
sprintf(mmc->name, "OMAP SD/MMC");
mmc->send_cmd = mmc_send_cmd;
@@ -624,11 +627,20 @@
#ifdef OMAP_HSMMC2_BASE
case 1:
priv_data->base_addr = (struct hsmmc *)OMAP_HSMMC2_BASE;
+#if (defined(CONFIG_OMAP44XX) || defined(CONFIG_OMAP54XX) || \
+ defined(CONFIG_DRA7XX)) && defined(CONFIG_HSMMC2_8BIT)
+ /* Enable 8-bit interface for eMMC on OMAP4/5 or DRA7XX */
+ host_caps_val |= MMC_MODE_8BIT;
+#endif
break;
#endif
#ifdef OMAP_HSMMC3_BASE
case 2:
priv_data->base_addr = (struct hsmmc *)OMAP_HSMMC3_BASE;
+#if defined(CONFIG_DRA7XX) && defined(CONFIG_HSMMC3_8BIT)
+ /* Enable 8-bit interface for eMMC on DRA7XX */
+ host_caps_val |= MMC_MODE_8BIT;
+#endif
break;
#endif
default:
@@ -644,8 +656,7 @@
mmc->getwp = omap_mmc_getwp;
mmc->voltages = MMC_VDD_32_33 | MMC_VDD_33_34 | MMC_VDD_165_195;
- mmc->host_caps = (MMC_MODE_4BIT | MMC_MODE_HS_52MHz | MMC_MODE_HS |
- MMC_MODE_HC) & ~host_caps_mask;
+ mmc->host_caps = host_caps_val & ~host_caps_mask;
mmc->f_min = 400000;