linux/drivers/mmc/host/sdhci-esdhc.h
Shawn Guo 74f330bcea mmc: sdhci-esdhc: break out early if clock is 0
Since commit 30832ab56 ("mmc: sdhci: Always pass clock request value
zero to set_clock host op") was merged, esdhc_set_clock starts hitting
"if (clock == 0)" where ESDHC_SYSTEM_CONTROL has been operated.  This
causes SDHCI card-detection function being broken.  Fix the regression
by moving "if (clock == 0)" above ESDHC_SYSTEM_CONTROL operation.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Chris Ball <cjb@laptop.org>
2012-09-04 13:58:06 -04:00

82 lines
2.2 KiB
C

/*
* Freescale eSDHC controller driver generics for OF and pltfm.
*
* Copyright (c) 2007 Freescale Semiconductor, Inc.
* Copyright (c) 2009 MontaVista Software, Inc.
* Copyright (c) 2010 Pengutronix e.K.
* Author: Wolfram Sang <w.sang@pengutronix.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License.
*/
#ifndef _DRIVERS_MMC_SDHCI_ESDHC_H
#define _DRIVERS_MMC_SDHCI_ESDHC_H
/*
* Ops and quirks for the Freescale eSDHC controller.
*/
#define ESDHC_DEFAULT_QUIRKS (SDHCI_QUIRK_FORCE_BLK_SZ_2048 | \
SDHCI_QUIRK_NO_BUSY_IRQ | \
SDHCI_QUIRK_NONSTANDARD_CLOCK | \
SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK | \
SDHCI_QUIRK_PIO_NEEDS_DELAY | \
SDHCI_QUIRK_RESTORE_IRQS_AFTER_RESET)
#define ESDHC_SYSTEM_CONTROL 0x2c
#define ESDHC_CLOCK_MASK 0x0000fff0
#define ESDHC_PREDIV_SHIFT 8
#define ESDHC_DIVIDER_SHIFT 4
#define ESDHC_CLOCK_PEREN 0x00000004
#define ESDHC_CLOCK_HCKEN 0x00000002
#define ESDHC_CLOCK_IPGEN 0x00000001
/* pltfm-specific */
#define ESDHC_HOST_CONTROL_LE 0x20
/* OF-specific */
#define ESDHC_DMA_SYSCTL 0x40c
#define ESDHC_DMA_SNOOP 0x00000040
#define ESDHC_HOST_CONTROL_RES 0x05
static inline void esdhc_set_clock(struct sdhci_host *host, unsigned int clock)
{
int pre_div = 2;
int div = 1;
u32 temp;
if (clock == 0)
goto out;
temp = sdhci_readl(host, ESDHC_SYSTEM_CONTROL);
temp &= ~(ESDHC_CLOCK_IPGEN | ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN
| ESDHC_CLOCK_MASK);
sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL);
while (host->max_clk / pre_div / 16 > clock && pre_div < 256)
pre_div *= 2;
while (host->max_clk / pre_div / div > clock && div < 16)
div++;
dev_dbg(mmc_dev(host->mmc), "desired SD clock: %d, actual: %d\n",
clock, host->max_clk / pre_div / div);
pre_div >>= 1;
div--;
temp = sdhci_readl(host, ESDHC_SYSTEM_CONTROL);
temp |= (ESDHC_CLOCK_IPGEN | ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN
| (div << ESDHC_DIVIDER_SHIFT)
| (pre_div << ESDHC_PREDIV_SHIFT));
sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL);
mdelay(1);
out:
host->clock = clock;
}
#endif /* _DRIVERS_MMC_SDHCI_ESDHC_H */