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The SDCLK is divided down from the host controller clock. Host controller clock may be different from the maximum SDCLK, so get it from the platform, instead of just using the max SDCLK. Signed-off-by: Lucas Stach <l.stach@pengutronix.de> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Chris Ball <cjb@laptop.org>
83 lines
2.2 KiB
C
83 lines
2.2 KiB
C
/*
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* Freescale eSDHC controller driver generics for OF and pltfm.
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*
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* Copyright (c) 2007 Freescale Semiconductor, Inc.
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* Copyright (c) 2009 MontaVista Software, Inc.
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* Copyright (c) 2010 Pengutronix e.K.
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* Author: Wolfram Sang <w.sang@pengutronix.de>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License.
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*/
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#ifndef _DRIVERS_MMC_SDHCI_ESDHC_H
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#define _DRIVERS_MMC_SDHCI_ESDHC_H
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/*
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* Ops and quirks for the Freescale eSDHC controller.
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*/
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#define ESDHC_DEFAULT_QUIRKS (SDHCI_QUIRK_FORCE_BLK_SZ_2048 | \
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SDHCI_QUIRK_NO_BUSY_IRQ | \
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SDHCI_QUIRK_NONSTANDARD_CLOCK | \
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SDHCI_QUIRK_DATA_TIMEOUT_USES_SDCLK | \
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SDHCI_QUIRK_PIO_NEEDS_DELAY | \
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SDHCI_QUIRK_RESTORE_IRQS_AFTER_RESET)
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#define ESDHC_SYSTEM_CONTROL 0x2c
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#define ESDHC_CLOCK_MASK 0x0000fff0
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#define ESDHC_PREDIV_SHIFT 8
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#define ESDHC_DIVIDER_SHIFT 4
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#define ESDHC_CLOCK_PEREN 0x00000004
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#define ESDHC_CLOCK_HCKEN 0x00000002
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#define ESDHC_CLOCK_IPGEN 0x00000001
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/* pltfm-specific */
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#define ESDHC_HOST_CONTROL_LE 0x20
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/* OF-specific */
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#define ESDHC_DMA_SYSCTL 0x40c
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#define ESDHC_DMA_SNOOP 0x00000040
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#define ESDHC_HOST_CONTROL_RES 0x05
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static inline void esdhc_set_clock(struct sdhci_host *host, unsigned int clock,
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unsigned int host_clock)
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{
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int pre_div = 2;
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int div = 1;
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u32 temp;
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if (clock == 0)
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goto out;
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temp = sdhci_readl(host, ESDHC_SYSTEM_CONTROL);
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temp &= ~(ESDHC_CLOCK_IPGEN | ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN
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| ESDHC_CLOCK_MASK);
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sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL);
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while (host_clock / pre_div / 16 > clock && pre_div < 256)
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pre_div *= 2;
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while (host_clock / pre_div / div > clock && div < 16)
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div++;
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dev_dbg(mmc_dev(host->mmc), "desired SD clock: %d, actual: %d\n",
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clock, host_clock / pre_div / div);
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pre_div >>= 1;
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div--;
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temp = sdhci_readl(host, ESDHC_SYSTEM_CONTROL);
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temp |= (ESDHC_CLOCK_IPGEN | ESDHC_CLOCK_HCKEN | ESDHC_CLOCK_PEREN
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| (div << ESDHC_DIVIDER_SHIFT)
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| (pre_div << ESDHC_PREDIV_SHIFT));
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sdhci_writel(host, temp, ESDHC_SYSTEM_CONTROL);
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mdelay(1);
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out:
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host->clock = clock;
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}
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#endif /* _DRIVERS_MMC_SDHCI_ESDHC_H */
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