From 1fcecf281b99f9ca262ae7fbc3703c421be5c857 Mon Sep 17 00:00:00 2001 From: Balaji T K Date: Wed, 1 Jun 2011 16:45:22 +0530 Subject: [PATCH] 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 Acked-by: Kishore Kadiyala Signed-off-by: Tony Lindgren --- arch/arm/mach-omap2/hsmmc.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/arch/arm/mach-omap2/hsmmc.c b/arch/arm/mach-omap2/hsmmc.c index 857f7daa3286..66868c5d5a29 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 */ -- 2.20.1