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 SA
 *
 * 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/kernel.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/highmem.h>
#include <linux/log2.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/amba/bus.h>
#include <linux/clk.h>
#include <linux/scatterlist.h>
#include <linux/gpio.h>
#include <linux/regulator/consumer.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/amba/mmci.h>
#include <linux/pm_runtime.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;

/**
 * struct variant_data - MMCI variant-specific quirks
 * @clkreg: default value for MCICLOCK register
 * @clkreg_enable: enable value for MMCICLOCK register
 * @datalength_bits: number of bits in the MMCIDATALENGTH register
 * @fifosize: number of bytes that can be written when MMCI_TXFIFOEMPTY
 *	      is asserted (likewise for RX)
 * @fifohalfsize: number of bytes that can be written when MCI_TXFIFOHALFEMPTY
 *		  is asserted (likewise for RX)
 * @sdio: variant supports SDIO
 * @st_clkdiv: true if using a ST-specific clock divider algorithm
 * @blksz_datactrl16: true if Block size is at b16..b30 position in datactrl register
 */
struct variant_data {
	unsigned int		clkreg;
	unsigned int		clkreg_enable;
	unsigned int		datalength_bits;
	unsigned int		fifosize;
	unsigned int		fifohalfsize;
	bool			sdio;
	bool			st_clkdiv;
	bool			blksz_datactrl16;
};

static struct variant_data variant_arm = {
	.fifosize		= 16 * 4,
	.fifohalfsize		= 8 * 4,
	.datalength_bits	= 16,
};

static struct variant_data variant_arm_extended_fifo = {
	.fifosize		= 128 * 4,
	.fifohalfsize		= 64 * 4,
	.datalength_bits	= 16,
};

static struct variant_data variant_u300 = {
	.fifosize		= 16 * 4,
	.fifohalfsize		= 8 * 4,
	.clkreg_enable		= MCI_ST_U300_HWFCEN,
	.datalength_bits	= 16,
	.sdio			= true,
};

static struct variant_data variant_ux500 = {
	.fifosize		= 30 * 4,
	.fifohalfsize		= 8 * 4,
	.clkreg			= MCI_CLK_ENABLE,
	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
	.datalength_bits	= 24,
	.sdio			= true,
	.st_clkdiv		= true,
};

static struct variant_data variant_ux500v2 = {
	.fifosize		= 30 * 4,
	.fifohalfsize		= 8 * 4,
	.clkreg			= MCI_CLK_ENABLE,
	.clkreg_enable		= MCI_ST_UX500_HWFCEN,
	.datalength_bits	= 24,
	.sdio			= true,
	.st_clkdiv		= true,
	.blksz_datactrl16	= true,
};

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

	if (desired) {
		if (desired >= host->mclk) {
			clk = MCI_CLK_BYPASS;
			if (variant->st_clkdiv)
				clk |= MCI_ST_UX500_NEG_EDGE;
			host->cclk = host->mclk;
		} else if (variant->st_clkdiv) {
			/*
			 * DB8500 TRM says f = mclk / (clkdiv + 2)
			 * => clkdiv = (mclk / f) - 2
			 * Round the divider up so we don't exceed the max
			 * frequency
			 */
			clk = DIV_ROUND_UP(host->mclk, desired) - 2;
			if (clk >= 256)
				clk = 255;
			host->cclk = host->mclk / (clk + 2);
		} else {
			/*
			 * PL180 TRM says f = mclk / (2 * (clkdiv + 1))
			 * => clkdiv = mclk / (2 * f) - 1
			 */
			clk = host->mclk / (2 * desired) - 1;
			if (clk >= 256)
				clk = 255;
			host->cclk = host->mclk / (2 * (clk + 1));
		}

		clk |= variant->clkreg_enable;
		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;

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

static void mmci_set_mask1(struct mmci_host *host, unsigned int mask)
{
	void __iomem *base = host->base;

	if (host->singleirq) {
		unsigned int mask0 = readl(base + MMCIMASK0);

		mask0 &= ~MCI_IRQ1MASK;
		mask0 |= mask;

		writel(mask0, base + MMCIMASK0);
	}

	writel(mask, base + MMCIMASK1);
}

static void mmci_stop_data(struct mmci_host *host)
{
	writel(0, host->base + MMCIDATACTRL);
	mmci_set_mask1(host, 0);
	host->data = NULL;
}

static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
{
	unsigned int flags = SG_MITER_ATOMIC;

	if (data->flags & MMC_DATA_READ)
		flags |= SG_MITER_TO_SG;
	else
		flags |= SG_MITER_FROM_SG;

	sg_miter_start(&host->sg_miter, data->sg, data->sg_len, flags);
}

/*
 * All the DMA operation mode stuff goes inside this ifdef.
 * This assumes that you have a generic DMA device interface,
 * no custom DMA interfaces are supported.
 */
#ifdef CONFIG_DMA_ENGINE
static void __devinit mmci_dma_setup(struct mmci_host *host)
{
	struct mmci_platform_data *plat = host->plat;
	const char *rxname, *txname;
	dma_cap_mask_t mask;

	if (!plat || !plat->dma_filter) {
		dev_info(mmc_dev(host->mmc), "no DMA platform data\n");
		return;
	}

	/* initialize pre request cookie */
	host->next_data.cookie = 1;

	/* Try to acquire a generic DMA engine slave channel */
	dma_cap_zero(mask);
	dma_cap_set(DMA_SLAVE, mask);

	/*
	 * If only an RX channel is specified, the driver will
	 * attempt to use it bidirectionally, however if it is
	 * is specified but cannot be located, DMA will be disabled.
	 */
	if (plat->dma_rx_param) {
		host->dma_rx_channel = dma_request_channel(mask,
							   plat->dma_filter,
							   plat->dma_rx_param);
		/* E.g if no DMA hardware is present */
		if (!host->dma_rx_channel)
			dev_err(mmc_dev(host->mmc), "no RX DMA channel\n");
	}

	if (plat->dma_tx_param) {
		host->dma_tx_channel = dma_request_channel(mask,
							   plat->dma_filter,
							   plat->dma_tx_param);
		if (!host->dma_tx_channel)
			dev_warn(mmc_dev(host->mmc), "no TX DMA channel\n");
	} else {
		host->dma_tx_channel = host->dma_rx_channel;
	}

	if (host->dma_rx_channel)
		rxname = dma_chan_name(host->dma_rx_channel);
	else
		rxname = "none";

	if (host->dma_tx_channel)
		txname = dma_chan_name(host->dma_tx_channel);
	else
		txname = "none";

	dev_info(mmc_dev(host->mmc), "DMA chann