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authorBalaji T K <balajitk@ti.com>2011-06-01 16:45:22 +0530
committerTony Lindgren <tony@atomide.com>2011-06-01 04:48:15 -0700
commit1fcecf281b99f9ca262ae7fbc3703c421be5c857 (patch)
tree2da4fdfd6c8c04cf476898a555777314e5c1012c /arch
parent1704bf15deb6de20f8f4272c8d8232b36bbc7484 (diff)
downloadop-kernel-dev-1fcecf281b99f9ca262ae7fbc3703c421be5c857.zip
op-kernel-dev-1fcecf281b99f9ca262ae7fbc3703c421be5c857.tar.gz
ARM: OMAP4: MMC: increase delay for pbias
4 micro seconds is not enough for PBIAS if MMC regulator is enabled from MMC regulator OFF. Increase the delay for PBIAS to stabilize. Wait for PBIAS and timeout if not. Resolves MMC/SD failure on OMAP4 "Pbias Voltage is not same as LDO" Signed-off-by: Balaji T K <balajitk@ti.com> Acked-by: Kishore Kadiyala <kishore.kadiyala@ti.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/arm/mach-omap2/hsmmc.c13
1 files changed, 10 insertions, 3 deletions
diff --git a/arch/arm/mach-omap2/hsmmc.c b/arch/arm/mach-omap2/hsmmc.c
index 857f7da..66868c5 100644
--- a/arch/arm/mach-omap2/hsmmc.c
+++ b/arch/arm/mach-omap2/hsmmc.c
@@ -145,6 +145,7 @@ static void omap4_hsmmc1_after_set_reg(struct device *dev, int slot,
int power_on, int vdd)
{
u32 reg;
+ unsigned long timeout;
if (power_on) {
reg = omap4_ctrl_pad_readl(control_pbias_offset);
@@ -157,9 +158,15 @@ static void omap4_hsmmc1_after_set_reg(struct device *dev, int slot,
OMAP4_MMC1_PWRDNZ_MASK |
OMAP4_USBC1_ICUSB_PWRDNZ_MASK);
omap4_ctrl_pad_writel(reg, control_pbias_offset);
- /* 4 microsec delay for comparator to generate an error*/
- udelay(4);
- reg = omap4_ctrl_pad_readl(control_pbias_offset);
+
+ timeout = jiffies + msecs_to_jiffies(5);
+ do {
+ reg = omap4_ctrl_pad_readl(control_pbias_offset);
+ if (!(reg & OMAP4_MMC1_PBIASLITE_VMODE_ERROR_MASK))
+ break;
+ usleep_range(100, 200);
+ } while (!time_after(jiffies, timeout));
+
if (reg & OMAP4_MMC1_PBIASLITE_VMODE_ERROR_MASK) {
pr_err("Pbias Voltage is not same as LDO\n");
/* Caution : On VMODE_ERROR Power Down MMC IO */
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