path: root/drivers/mmc/host/mmci.c

/*
 *  linux/drivers/mmc/host/mmci.c - ARM PrimeCell MMCI PL180/1 driver
 *
 *  Copyright (C) 2003 Deep Blue Solutions, Ltd, All Rights Reserved.
 *  Copyright (C) 2010 ST-Ericsson AB.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/highmem.h>
#include <linux/log2.h>
#include <linux/mmc/host.h>
#include <linux/amba/bus.h>
#include <linux/clk.h>
#include <linux/scatterlist.h>
#include <linux/gpio.h>
#include <linux/amba/mmci.h>
#include <linux/regulator/consumer.h>

#include <asm/cacheflush.h>
#include <asm/div64.h>
#include <asm/io.h>
#include <asm/sizes.h>

#include "mmci.h"

#define DRIVER_NAME "mmci-pl18x"

static unsigned int fmax = 515633;

/*
 * This must be called with host->lock held
 */
static void mmci_set_clkreg(struct mmci_host *host, unsigned int desired)
{
	u32 clk = 0;

	if (desired) {
		if (desired >= host->mclk) {
			clk = MCI_CLK_BYPASS;
			host->cclk = host->mclk;
		} else {
			clk = host->mclk / (2 * desired) - 1;
			if (clk >= 256)
				clk = 255;
			host->cclk = host->mclk / (2 * (clk + 1));
		}
		if (host->hw_designer == AMBA_VENDOR_ST)
			clk |= MCI_ST_FCEN; /* Bug fix in ST IP block */
		clk |= MCI_CLK_ENABLE;
		/* This hasn't proven to be worthwhile */
		/* clk |= MCI_CLK_PWRSAVE; */
	}

	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_4)
		clk |= MCI_4BIT_BUS;
	if (host->mmc->ios.bus_width == MMC_BUS_WIDTH_8)
		clk |= MCI_ST_8BIT_BUS;

	writel(clk, host->base + MMCICLOCK);
}

static void
mmci_request_end(struct mmci_host *host, struct mmc_request *mrq)
{
	writel(0, host->base + MMCICOMMAND);

	BUG_ON(host->data);

	host->mrq = NULL;
	host->cmd = NULL;

	if (mrq->data)
		mrq->data->bytes_xfered = host->data_xfered;

	/*
	 * Need to drop the host lock here; mmc_request_done may call
	 * back into the driver...
	 */
	spin_unlock(&host->lock);
	mmc_request_done(host->mmc, mrq);
	spin_lock(&host->lock);
}

static void mmci_stop_data(struct mmci_host *host)
{
	writel(0, host->base + MMCIDATACTRL);
	writel(0, host->base + MMCIMASK1);
	host->data = NULL;
}

static void mmci_start_data(struct mmci_host *host, struct mmc_data *data)
{
	unsigned int datactrl, timeout, irqmask;
	unsigned long long clks;
	void __iomem *base;
	int blksz_bits;

	dev_dbg(mmc_dev(host->mmc), "blksz %04x blks %04x flags %08x\n",
		data->blksz, data->blocks, data->flags);

	host->data = data;
	host->size = data->blksz;
	host->data_xfered = 0;

	mmci_init_sg(host, data);

	clks = (unsigned long long)data->timeout_ns * host->cclk;
	do_div(clks, 1000000000UL);

	timeout = data->timeout_clks + (unsigned int)clks;

	base = host->base;
	writel(timeout, base + MMCIDATATIMER);
	writel(host->size, base + MMCIDATALENGTH);

	blksz_bits = ffs(data->blksz) - 1;
	BUG_ON(1 << blksz_bits != data->blksz);

	datactrl = MCI_DPSM_ENABLE | blksz_bits << 4;
	if (data->flags & MMC_DATA_READ) {
		datactrl |= MCI_DPSM_DIRECTION;
		irqmask = MCI_RXFIFOHALFFULLMASK;

		/*
		 * If we have less than a FIFOSIZE of bytes to transfer,
		 * trigger a PIO interrupt as soon as any data is available.
		 */
		if (host->size < MCI_FIFOSIZE)
			irqmask |= MCI_RXDATAAVLBLMASK;
	} else {
		/*
		 * We don't actually need to include "FIFO empty" here
		 * since its implicit in "FIFO half empty".
		 */
		irqmask = MCI_TXFIFOHALFEMPTYMASK;
	}

	writel(datactrl, base + MMCIDATACTRL);
	writel(readl(base + MMCIMASK0) & ~MCI_DATAENDMASK, base + MMCIMASK0);
	writel(irqmask, base + MMCIMASK1);
}

static void
mmci_start_command(struct mmci_host *host, struct mmc_command *cmd, u32 c)
{
	void __iomem *base = host->base;

	dev_dbg(mmc_dev(host->mmc), "op %02x arg %08x flags %08x\n",
	    cmd->opcode, cmd->arg, cmd->flags);

	if (readl(base + MMCICOMMAND) & MCI_CPSM_ENABLE