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

/*
 *  linux/drivers/mmc/host/omap.c
 *
 *  Copyright (C) 2004 Nokia Corporation
 *  Written by Tuukka Tikkanen and Juha Yrjölä<juha.yrjola@nokia.com>
 *  Misc hacks here and there by Tony Lindgren <tony@atomide.com>
 *  Other hacks (DMA, SD, etc) by David Brownell
 *
 * 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/platform_device.h>
#include <linux/interrupt.h>
#include <linux/dmaengine.h>
#include <linux/dma-mapping.h>
#include <linux/delay.h>
#include <linux/spinlock.h>
#include <linux/timer.h>
#include <linux/of.h>
#include <linux/mmc/host.h>
#include <linux/mmc/card.h>
#include <linux/mmc/mmc.h>
#include <linux/clk.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>
#include <linux/platform_data/mmc-omap.h>


#define	OMAP_MMC_REG_CMD	0x00
#define	OMAP_MMC_REG_ARGL	0x01
#define	OMAP_MMC_REG_ARGH	0x02
#define	OMAP_MMC_REG_CON	0x03
#define	OMAP_MMC_REG_STAT	0x04
#define	OMAP_MMC_REG_IE		0x05
#define	OMAP_MMC_REG_CTO	0x06
#define	OMAP_MMC_REG_DTO	0x07
#define	OMAP_MMC_REG_DATA	0x08
#define	OMAP_MMC_REG_BLEN	0x09
#define	OMAP_MMC_REG_NBLK	0x0a
#define	OMAP_MMC_REG_BUF	0x0b
#define	OMAP_MMC_REG_SDIO	0x0d
#define	OMAP_MMC_REG_REV	0x0f
#define	OMAP_MMC_REG_RSP0	0x10
#define	OMAP_MMC_REG_RSP1	0x11
#define	OMAP_MMC_REG_RSP2	0x12
#define	OMAP_MMC_REG_RSP3	0x13
#define	OMAP_MMC_REG_RSP4	0x14
#define	OMAP_MMC_REG_RSP5	0x15
#define	OMAP_MMC_REG_RSP6	0x16
#define	OMAP_MMC_REG_RSP7	0x17
#define	OMAP_MMC_REG_IOSR	0x18
#define	OMAP_MMC_REG_SYSC	0x19
#define	OMAP_MMC_REG_SYSS	0x1a

#define	OMAP_MMC_STAT_CARD_ERR		(1 << 14)
#define	OMAP_MMC_STAT_CARD_IRQ		(1 << 13)
#define	OMAP_MMC_STAT_OCR_BUSY		(1 << 12)
#define	OMAP_MMC_STAT_A_EMPTY		(1 << 11)
#define	OMAP_MMC_STAT_A_FULL		(1 << 10)
#define	OMAP_MMC_STAT_CMD_CRC		(1 <<  8)
#define	OMAP_MMC_STAT_CMD_TOUT		(1 <<  7)
#define	OMAP_MMC_STAT_DATA_CRC		(1 <<  6)
#define	OMAP_MMC_STAT_DATA_TOUT		(1 <<  5)
#define	OMAP_MMC_STAT_END_BUSY		(1 <<  4)
#define	OMAP_MMC_STAT_END_OF_DATA	(1 <<  3)
#define	OMAP_MMC_STAT_CARD_BUSY		(1 <<  2)
#define	OMAP_MMC_STAT_END_OF_CMD	(1 <<  0)

#define mmc_omap7xx()	(host->features & MMC_OMAP7XX)
#define mmc_omap15xx()	(host->features & MMC_OMAP15XX)
#define mmc_omap16xx()	(host->features & MMC_OMAP16XX)
#define MMC_OMAP1_MASK	(MMC_OMAP7XX | MMC_OMAP15XX | MMC_OMAP16XX)
#define mmc_omap1()	(host->features & MMC_OMAP1_MASK)
#define mmc_omap2()	(!mmc_omap1())

#define OMAP_MMC_REG(host, reg)		(OMAP_MMC_REG_##reg << (host)->reg_shift)
#define OMAP_MMC_READ(host, reg)	__raw_readw((host)->virt_base + OMAP_MMC_REG(host, reg))
#define OMAP_MMC_WRITE(host, reg, val)	__raw_writew((val), (host)->virt_base + OMAP_MMC_REG(host, reg))

/*
 * Command types
 */
#define OMAP_MMC_CMDTYPE_BC	0
#define OMAP_MMC_CMDTYPE_BCR	1
#define OMAP_MMC_CMDTYPE_AC	2
#define OMAP_MMC_CMDTYPE_ADTC	3

#define DRIVER_NAME "mmci-omap"

/* Specifies how often in millisecs to poll for card status changes
 * when the cover switch is open */
#define OMAP_MMC_COVER_POLL_DELAY	500

struct mmc_omap_host;

struct mmc_omap_slot {
	int			id;
	unsigned int		vdd;
	u16			saved_con;
	u16			bus_mode;
	u16			power_mode;
	unsigned int		fclk_freq;

	struct tasklet_struct	cover_tasklet;
	struct timer_list       cover_timer;
	unsigned		cover_open;

	struct mmc_request      *mrq;
	struct mmc_omap_host    *host;
	struct mmc_host		*mmc;
	struct omap_mmc_slot_data *pdata;
};

struct mmc_omap_host {
	int			initialized;
	struct mmc_request *	mrq;
	struct mmc_command *	cmd;
	struct mmc_data *	data;
	struct mmc_host *	mmc;
	struct device *		dev;
	unsigned char		id; /* 16xx chips have 2 MMC blocks */
	struct clk *		iclk;
	struct clk *		fclk;
	struct dma_chan		*dma_rx;
	u32			dma_rx_burst;
	struct dma_chan		*dma_tx;
	u32			dma_tx_burst;
	void __iomem		*virt_base;
	unsigned int		phys_base;
	int			irq;
	unsigned char		bus_mode;
	unsigned int		reg_shift;

	struct work_struct	cmd_abort_work;
	unsigned		abort:1;
	struct timer_list	cmd_abort_timer;

	struct work_struct      slot_release_work;
	struct mmc_omap_slot    *next_slot;
	struct work_struct      send_stop_work;
	struct mmc_data		*stop_data;

	unsigned int		sg_len;
	int			sg_idx;
	u16 *			buffer;
	u32			buffer_bytes_left;
	u32			total_bytes_left;

	unsigned		features;
	unsigned		brs_received:1, dma_done:1;
	unsigned		dma_in_use:1;
	spinlock_t		dma_lock;

	struct mmc_omap_slot    *slots[OMAP_MMC_MAX_SLOTS];
	struct mmc_omap_slot    *current_slot;
	spinlock_t              slot_lock;
	wait_queue_head_t       slot_wq;
	int                     nr_slots;

	struct timer_list       clk_timer;
	spinlock_t		clk_lock;     /* for changing enabled state */
	unsigned int            fclk_enabled:1;
	struct workqueue_struct *mmc_omap_wq;

	struct omap_mmc_platform_data *pdata;
};


static void mmc_omap_fclk_offdelay(struct mmc_omap_slot *slot)
{
	unsigned long tick_ns;

	if (slot != NULL && slot->host->fclk_enabled && slot->fclk_freq > 0) {
		tick_ns = DIV_ROUND_UP(NSEC_PER_SEC, slot->fclk_freq);
		ndelay(8 * tick_ns);
	}
}

static void mmc_omap_fclk_enable(struct mmc_omap_host *host, unsigned int enable)
{
	unsigned long flags;

	spin_lock_irqsave(&host->clk_lock, flags);
	if (host->fclk_enabled != enable) {
		host->fclk_enabled = enable;
		if (enable)
			clk_enable(host->fclk);
		else
			clk_disable(host->fclk);
	}
	spin_unlock_irqrestore(&host->clk_lock, flags);
}

static void mmc_omap_select_slot(struct mmc_omap_slot *slot, int claimed)
{
	struct mmc_omap_host *host = slot->host;
	unsigned long flags;

	if (claimed)
		goto no_claim;
	spin_lock_irqsave(&host->slot_lock, flags);
	while (host->mmc != NULL) {
		spin_unlock_irqrestore(&host->slot_lock, flags);
		wait_event(host->slot_wq, host->mmc == NULL);
		spin_lock_irqsave(&host->slot_lock, flags);
	}
	host->mmc = slot->mmc;
	spin_unlock_irqrestore(&host->slot_lock, flags);
no_claim:
	del_timer(&host->clk_timer);
	if (host->current_slot != slot || !claimed)
		mmc_omap_fclk_offdelay(host->current_slot);

	if (host->current_slot != slot) {
		OMAP_MMC_WRITE(host, CON, slot->saved_con & 0xFC00);
		if (host->pdata->switch_slot != NULL)
			host->pdata->switch_slot(mmc_dev(slot->mmc), slot->id);
		host->current_slot = slot;
	}

	if (claimed) {
		mmc_omap_fclk_enable(host, 1);

		/* Doing the dummy read here seems to work around some bug
		 * at least in OMAP24xx silicon where the command would not
		 * start after writing the CMD register. Sigh. */
		OMAP_MMC_READ(host, CON);

		OMAP_MMC_WRITE(host, CON, slot->saved_con);
	} else
		mmc_omap_fclk_enable(host, 0);
}

static void mmc_omap_start_request(struct mmc_omap_host *host,
				   struct mmc_request *req);

static void mmc_omap_slot_release_work(struct work_struct *work)
{
	struct mmc_omap_host *host = container_of(work, struct mmc_omap_host,
						  slot_release_work);
	struct mmc_omap_slot *next_slot = host->next_slot;
	struct mmc_request *rq;

	host->next_slot = NULL;
	mmc_omap_select_slot(next_slot, 1);

	rq = next_slot->mrq;
	next_slot->mrq = NULL;
	mmc_omap_start_request(host, rq);
}

static void mmc_omap_release_slot(struct mmc_omap_slot *slot, int clk_enabled)
{
	struct mmc_omap_host *host = slot->host;
	unsigned long flags;
	int i;

	BUG_ON(slot == NULL || host->mmc == NULL);

	if (clk_enabled)
		/* Keeps clock running for at least 8 cycles on valid freq */
		mod_timer(&host->clk_timer, jiffies  + HZ/10)