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 <mboa...@prograde.net>.
A minor cosmetic fix in a comment as well.
Signed-off-by: Lubomir Popov <lpo...@mm-sol.com>
---
Tested on a custom OMAP5430 board with a SanDisk 8 GB eMMC, and on a TI
750-2172 Processor Board (with OMAP4460 ES1.1 and a 32 GB SanDisk eMMC),
mounted on a custom main board. Actual performance gain is negligible as
compared to 4-bit mode (about 2 ms faster FAT loading for a 4 MB image on
the 4460, that is in the range of 1%), but the advantage is that the eMMC
interface can be electrically validated in U-Boot.
drivers/mmc/omap_hsmmc.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/mmc/omap_hsmmc.c b/drivers/mmc/omap_hsmmc.c
index 975b2c5..08e2c8b 100644
--- a/drivers/mmc/omap_hsmmc.c
+++ b/drivers/mmc/omap_hsmmc.c
@@ -376,6 +376,7 @@ static int mmc_send_cmd(struct mmc *mmc, struct mmc_cmd
*cmd,
}
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);
@@ -480,7 +481,7 @@ static int mmc_write_data(struct hsmmc *mmc_base, const
char *buf,
unsigned int count;
/*
- * Start Polled Read
+ * Start Polled Write
*/
count = (size > MMCSD_SECTOR_SIZE) ? MMCSD_SECTOR_SIZE : size;
count /= 4;
@@ -586,6 +587,8 @@ int omap_mmc_init(int dev_index, uint host_caps_mask, uint
f_max, int cd_gpio,
{
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;
@@ -600,11 +603,20 @@ int omap_mmc_init(int dev_index, uint host_caps_mask,
uint f_max, int cd_gpio,
#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:
--
1.7.9.5
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