[deliverable/linux.git] / drivers / spi / spi_mpc83xx.c

/*
 * MPC83xx SPI controller driver.
 *
 * Maintainer: Kumar Gala
 *
 * Copyright (C) 2006 Polycom, Inc.
 *
 * 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, or (at your
 * option) any later version.
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/completion.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/irq.h>
#include <linux/device.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/platform_device.h>
#include <linux/fsl_devices.h>

#include <asm/irq.h>
#include <asm/io.h>

/* SPI Controller registers */
struct mpc83xx_spi_reg {
	u8 res1[0x20];
	__be32 mode;
	__be32 event;
	__be32 mask;
	__be32 command;
	__be32 transmit;
	__be32 receive;
};

/* SPI Controller mode register definitions */
#define	SPMODE_CI_INACTIVEHIGH	(1 << 29)
#define	SPMODE_CP_BEGIN_EDGECLK	(1 << 28)
#define	SPMODE_DIV16		(1 << 27)
#define	SPMODE_REV		(1 << 26)
#define	SPMODE_MS		(1 << 25)
#define	SPMODE_ENABLE		(1 << 24)
#define	SPMODE_LEN(x)		((x) << 20)
#define	SPMODE_PM(x)		((x) << 16)

/*
 * Default for SPI Mode:
 * 	SPI MODE 0 (inactive low, phase middle, MSB, 8-bit length, slow clk
 */
#define	SPMODE_INIT_VAL (SPMODE_CI_INACTIVEHIGH | SPMODE_DIV16 | SPMODE_REV | \
			 SPMODE_MS | SPMODE_LEN(7) | SPMODE_PM(0xf))

/* SPIE register values */
#define	SPIE_NE		0x00000200	/* Not empty */
#define	SPIE_NF		0x00000100	/* Not full */

/* SPIM register values */
#define	SPIM_NE		0x00000200	/* Not empty */
#define	SPIM_NF		0x00000100	/* Not full */

/* SPI Controller driver's private data. */
struct mpc83xx_spi {
	/* bitbang has to be first */
	struct spi_bitbang bitbang;
	struct completion done;

	struct mpc83xx_spi_reg __iomem *base;

	/* rx & tx bufs from the spi_transfer */
	const void *tx;
	void *rx;

	/* functions to deal with different sized buffers */
	void (*get_rx) (u32 rx_data, struct mpc83xx_spi *);
	u32(*get_tx) (struct mpc83xx_spi *);

	unsigned int count;
	u32 irq;

	unsigned nsecs;		/* (clock cycle time)/2 */

	u32 sysclk;
	void (*activate_cs) (u8 cs, u8 polarity);
	void (*deactivate_cs) (u8 cs, u8 polarity);
};

static inline void mpc83xx_spi_write_reg(__be32 __iomem * reg, u32 val)
{
	out_be32(reg, val);
}

static inline u32 mpc83xx_spi_read_reg(__be32 __iomem * reg)
{
	return in_be32(reg);
}

#define MPC83XX_SPI_RX_BUF(type) 					  \
void mpc83xx_spi_rx_buf_##type(u32 data, struct mpc83xx_spi *mpc83xx_spi) \
{									  \
	type * rx = mpc83xx_spi->rx;					  \
	*rx++ = (type)data;						  \
	mpc83xx_spi->rx = rx;						  \
}

#define MPC83XX_SPI_TX_BUF(type)				\
u32 mpc83xx_spi_tx_buf_##type(struct mpc83xx_spi *mpc83xx_spi)	\
{								\
	u32 data;						\
	const type * tx = mpc83xx_spi->tx;			\
	if (!tx)						\
		return 0;					\
	data = *tx++;						\
	mpc83xx_spi->tx = tx;					\
	return data;						\
}

MPC83XX_SPI_RX_BUF(u8)
MPC83XX_SPI_RX_BUF(u16)
MPC83XX_SPI_RX_BUF(u32)
MPC83XX_SPI_TX_BUF(u8)
MPC83XX_SPI_TX_BUF(u16)
MPC83XX_SPI_TX_BUF(u32)

static void mpc83xx_spi_chipselect(struct spi_device *spi, int value)
{
	struct mpc83xx_spi *mpc83xx_spi;
	u8 pol = spi->mode & SPI_CS_HIGH ? 1 : 0;

	mpc83xx_spi = spi_master_get_devdata(spi->master);

	if (value == BITBANG_CS_INACTIVE) {
		if (mpc83xx_spi->deactivate_cs)
			mpc83xx_spi->deactivate_cs(spi->chip_select, pol);
	}

	if (value == BITBANG_CS_ACTIVE) {
		u32 regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
		u32 len = spi->bits_per_word;
		if (len == 32)
			len = 0;
		else
			len = len - 1;

		/* mask out bits we are going to set */
		regval &= ~0x38ff0000;

		if (spi->mode & SPI_CPHA)
			regval |= SPMODE_CP_BEGIN_EDGECLK;
		if (spi->mode & SPI_CPOL)
			regval |= SPMODE_CI_INACTIVEHIGH;

		regval |= SPMODE_LEN(len);

		if ((mpc83xx_spi->sysclk / spi->max_speed_hz) >= 64) {
			u8 pm = mpc83xx_spi->sysclk / (spi->max_speed_hz * 64);
			regval |= SPMODE_PM(pm) | SPMODE_DIV16;
		} else {
			u8 pm = mpc83xx_spi->sysclk / (spi->max_speed_hz * 4);
			regval |= SPMODE_PM(pm);
		}

		mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
		if (mpc83xx_spi->activate_cs)
			mpc83xx_spi->activate_cs(spi->chip_select, pol);
	}
}

static
int mpc83xx_spi_setup_transfer(struct spi_device *spi, struct spi_transfer *t)
{
	struct mpc83xx_spi *mpc83xx_spi;
	u32 regval;
	u8 bits_per_word;
	u32 hz;

	mpc83xx_spi = spi_master_get_devdata(spi->master);

	if (t) {
		bits_per_word = t->bits_per_word;
		hz = t->speed_hz;
	} else {
		bits_per_word = 0;
		hz = 0;
	}

	/* spi_transfer level calls that work per-word */
	if (!bits_per_word)
		bits_per_word = spi->bits_per_word;

	/* Make sure its a bit width we support [4..16, 32] */
	if ((bits_per_word < 4)
	    || ((bits_per_word > 16) && (bits_per_word != 32)))
		return -EINVAL;

	if (bits_per_word <= 8) {
		mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
		mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;
	} else if (bits_per_word <= 16) {
		mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u16;
		mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u16;
	} else if (bits_per_word <= 32) {
		mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u32;
		mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u32;
	} else
		return -EINVAL;

	/* nsecs = (clock period)/2 */
	if (!hz)
		hz = spi->max_speed_hz;
	mpc83xx_spi->nsecs = (1000000000 / 2) / hz;
	if (mpc83xx_spi->nsecs > MAX_UDELAY_MS * 1000)
		return -EINVAL;

	if (bits_per_word == 32)
		bits_per_word = 0;
	else
		bits_per_word = bits_per_word - 1;

	regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);

	/* Mask out bits_per_wordgth */
	regval &= 0xff0fffff;
	regval |= SPMODE_LEN(bits_per_word);

	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);

	return 0;
}

/* the spi->mode bits understood by this driver: */
#define MODEBITS (SPI_CPOL | SPI_CPHA | SPI_CS_HIGH)

static int mpc83xx_spi_setup(struct spi_device *spi)
{
	struct spi_bitbang *bitbang;
	struct mpc83xx_spi *mpc83xx_spi;
	int retval;

	if (spi->mode & ~MODEBITS) {
		dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
			spi->mode & ~MODEBITS);
		return -EINVAL;
	}

	if (!spi->max_speed_hz)
		return -EINVAL;

	bitbang = spi_master_get_devdata(spi->master);
	mpc83xx_spi = spi_master_get_devdata(spi->master);

	if (!spi->bits_per_word)
		spi->bits_per_word = 8;

	retval = mpc83xx_spi_setup_transfer(spi, NULL);
	if (retval < 0)
		return retval;

	dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec\n",
		__FUNCTION__, spi->mode & (SPI_CPOL | SPI_CPHA),
		spi->bits_per_word, 2 * mpc83xx_spi->nsecs);

	/* NOTE we _need_ to call chipselect() early, ideally with adapter
	 * setup, unless the hardware defaults cooperate to avoid confusion
	 * between normal (active low) and inverted chipselects.
	 */

	/* deselect chip (low or high) */
	spin_lock(&bitbang->lock);
	if (!bitbang->busy) {
		bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
		ndelay(mpc83xx_spi->nsecs);
	}
	spin_unlock(&bitbang->lock);

	return 0;
}

static int mpc83xx_spi_bufs(struct spi_device *spi, struct spi_transfer *t)
{
	struct mpc83xx_spi *mpc83xx_spi;
	u32 word;

	mpc83xx_spi = spi_master_get_devdata(spi->master);

	mpc83xx_spi->tx = t->tx_buf;
	mpc83xx_spi->rx = t->rx_buf;
	mpc83xx_spi->count = t->len;
	INIT_COMPLETION(mpc83xx_spi->done);

	/* enable rx ints */
	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, SPIM_NE);

	/* transmit word */
	word = mpc83xx_spi->get_tx(mpc83xx_spi);
	mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit, word);

	wait_for_completion(&mpc83xx_spi->done);

	/* disable rx ints */
	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0);

	return t->len - mpc83xx_spi->count;
}

irqreturn_t mpc83xx_spi_irq(s32 irq, void *context_data)
{
	struct mpc83xx_spi *mpc83xx_spi = context_data;
	u32 event;
	irqreturn_t ret = IRQ_NONE;

	/* Get interrupt events(tx/rx) */
	event = mpc83xx_spi_read_reg(&mpc83xx_spi->base->event);

	/* We need handle RX first */
	if (event & SPIE_NE) {
		u32 rx_data = mpc83xx_spi_read_reg(&mpc83xx_spi->base->receive);

		if (mpc83xx_spi->rx)
			mpc83xx_spi->get_rx(rx_data, mpc83xx_spi);

		ret = IRQ_HANDLED;
	}

	if ((event & SPIE_NF) == 0)
		/* spin until TX is done */
		while (((event =
			 mpc83xx_spi_read_reg(&mpc83xx_spi->base->event)) &
						SPIE_NF) == 0)
			 cpu_relax();

	mpc83xx_spi->count -= 1;
	if (mpc83xx_spi->count) {
		if (mpc83xx_spi->tx) {
			u32 word = mpc83xx_spi->get_tx(mpc83xx_spi);
			mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit,
					      word);
		}
	} else {
		complete(&mpc83xx_spi->done);
	}

	/* Clear the events */
	mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, event);

	return ret;
}

static int __init mpc83xx_spi_probe(struct platform_device *dev)
{
	struct spi_master *master;
	struct mpc83xx_spi *mpc83xx_spi;
	struct fsl_spi_platform_data *pdata;
	struct resource *r;
	u32 regval;
	int ret = 0;

	/* Get resources(memory, IRQ) associated with the device */
	master = spi_alloc_master(&dev->dev, sizeof(struct mpc83xx_spi));

	if (master == NULL) {
		ret = -ENOMEM;
		goto err;
	}

	platform_set_drvdata(dev, master);
	pdata = dev->dev.platform_data;

	if (pdata == NULL) {
		ret = -ENODEV;
		goto free_master;
	}

	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
	if (r == NULL) {
		ret = -ENODEV;
		goto free_master;
	}

	mpc83xx_spi = spi_master_get_devdata(master);
	mpc83xx_spi->bitbang.master = spi_master_get(master);
	mpc83xx_spi->bitbang.chipselect = mpc83xx_spi_chipselect;
	mpc83xx_spi->bitbang.setup_transfer = mpc83xx_spi_setup_transfer;
	mpc83xx_spi->bitbang.txrx_bufs = mpc83xx_spi_bufs;
	mpc83xx_spi->sysclk = pdata->sysclk;
	mpc83xx_spi->activate_cs = pdata->activate_cs;
	mpc83xx_spi->deactivate_cs = pdata->deactivate_cs;
	mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
	mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;

	mpc83xx_spi->bitbang.master->setup = mpc83xx_spi_setup;
	init_completion(&mpc83xx_spi->done);

	mpc83xx_spi->base = ioremap(r->start, r->end - r->start + 1);
	if (mpc83xx_spi->base == NULL) {
		ret = -ENOMEM;
		goto put_master;
	}

	mpc83xx_spi->irq = platform_get_irq(dev, 0);

	if (mpc83xx_spi->irq < 0) {
		ret = -ENXIO;
		goto unmap_io;
	}

	/* Register for SPI Interrupt */
	ret = request_irq(mpc83xx_spi->irq, mpc83xx_spi_irq,
			  0, "mpc83xx_spi", mpc83xx_spi);

	if (ret != 0)
		goto unmap_io;

	master->bus_num = pdata->bus_num;
	master->num_chipselect = pdata->max_chipselect;

	/* SPI controller initializations */
	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0);
	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0);
	mpc83xx_spi_write_reg(&mpc83xx_spi->base->command, 0);
	mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, 0xffffffff);

	/* Enable SPI interface */
	regval = pdata->initial_spmode | SPMODE_INIT_VAL | SPMODE_ENABLE;
	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);

	ret = spi_bitbang_start(&mpc83xx_spi->bitbang);

	if (ret != 0)
		goto free_irq;

	printk(KERN_INFO
	       "%s: MPC83xx SPI Controller driver at 0x%p (irq = %d)\n",
	       dev->dev.bus_id, mpc83xx_spi->base, mpc83xx_spi->irq);

	return ret;

free_irq:
	free_irq(mpc83xx_spi->irq, mpc83xx_spi);
unmap_io:
	iounmap(mpc83xx_spi->base);
put_master:
	spi_master_put(master);
free_master:
	kfree(master);
err:
	return ret;
}

static int __devexit mpc83xx_spi_remove(struct platform_device *dev)
{
	struct mpc83xx_spi *mpc83xx_spi;
	struct spi_master *master;

	master = platform_get_drvdata(dev);
	mpc83xx_spi = spi_master_get_devdata(master);

	spi_bitbang_stop(&mpc83xx_spi->bitbang);
	free_irq(mpc83xx_spi->irq, mpc83xx_spi);
	iounmap(mpc83xx_spi->base);
	spi_master_put(mpc83xx_spi->bitbang.master);

	return 0;
}

static struct platform_driver mpc83xx_spi_driver = {
	.probe = mpc83xx_spi_probe,
	.remove = __devexit_p(mpc83xx_spi_remove),
	.driver = {
		   .name = "mpc83xx_spi",
	},
};

static int __init mpc83xx_spi_init(void)
{
	return platform_driver_register(&mpc83xx_spi_driver);
}

static void __exit mpc83xx_spi_exit(void)
{
	platform_driver_unregister(&mpc83xx_spi_driver);
}

module_init(mpc83xx_spi_init);
module_exit(mpc83xx_spi_exit);

MODULE_AUTHOR("Kumar Gala");
MODULE_DESCRIPTION("Simple MPC83xx SPI Driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
ccf06998 KG	1	/*
	2	* MPC83xx SPI controller driver.
	3	*
	4	* Maintainer: Kumar Gala
	5	*
	6	* Copyright (C) 2006 Polycom, Inc.
	7	*
	8	* This program is free software; you can redistribute it and/or modify it
	9	* under the terms of the GNU General Public License as published by the
	10	* Free Software Foundation; either version 2 of the License, or (at your
	11	* option) any later version.
	12	*/
	13	#include <linux/module.h>
	14	#include <linux/init.h>
	15	#include <linux/types.h>
	16	#include <linux/kernel.h>
	17	#include <linux/completion.h>
	18	#include <linux/interrupt.h>
	19	#include <linux/delay.h>
	20	#include <linux/irq.h>
	21	#include <linux/device.h>
	22	#include <linux/spi/spi.h>
	23	#include <linux/spi/spi_bitbang.h>
	24	#include <linux/platform_device.h>
	25	#include <linux/fsl_devices.h>
	26
	27	#include <asm/irq.h>
	28	#include <asm/io.h>
	29
	30	/* SPI Controller registers */
	31	struct mpc83xx_spi_reg {
	32	u8 res1[0x20];
	33	__be32 mode;
	34	__be32 event;
	35	__be32 mask;
	36	__be32 command;
	37	__be32 transmit;
	38	__be32 receive;
	39	};
	40
	41	/* SPI Controller mode register definitions */
	42	#define SPMODE_CI_INACTIVEHIGH (1 << 29)
	43	#define SPMODE_CP_BEGIN_EDGECLK (1 << 28)
	44	#define SPMODE_DIV16 (1 << 27)
	45	#define SPMODE_REV (1 << 26)
	46	#define SPMODE_MS (1 << 25)
	47	#define SPMODE_ENABLE (1 << 24)
	48	#define SPMODE_LEN(x) ((x) << 20)
	49	#define SPMODE_PM(x) ((x) << 16)
	50
	51	/*
	52	* Default for SPI Mode:
	53	* SPI MODE 0 (inactive low, phase middle, MSB, 8-bit length, slow clk
	54	*/
	55	#define SPMODE_INIT_VAL (SPMODE_CI_INACTIVEHIGH \| SPMODE_DIV16 \| SPMODE_REV \| \
	56	SPMODE_MS \| SPMODE_LEN(7) \| SPMODE_PM(0xf))
	57
	58	/* SPIE register values */
	59	#define SPIE_NE 0x00000200 /* Not empty */
	60	#define SPIE_NF 0x00000100 /* Not full */
	61
	62	/* SPIM register values */
	63	#define SPIM_NE 0x00000200 /* Not empty */
	64	#define SPIM_NF 0x00000100 /* Not full */
65
66	/* SPI Controller driver's private data. */
67	struct mpc83xx_spi {
68	/* bitbang has to be first */
69	struct spi_bitbang bitbang;
70	struct completion done;
71
72	struct mpc83xx_spi_reg __iomem *base;
73
74	/* rx & tx bufs from the spi_transfer */
75	const void *tx;
76	void *rx;
77
78	/* functions to deal with different sized buffers */
79	void (get_rx) (u32 rx_data, struct mpc83xx_spi );
80	u32(get_tx) (struct mpc83xx_spi );
81
82	unsigned int count;
83	u32 irq;
84
85	unsigned nsecs; /* (clock cycle time)/2 */
86
87	u32 sysclk;
88	void (*activate_cs) (u8 cs, u8 polarity);
89	void (*deactivate_cs) (u8 cs, u8 polarity);
90	};
91
92	static inline void mpc83xx_spi_write_reg(__be32 __iomem * reg, u32 val)
93	{
94	out_be32(reg, val);
95	}
96
97	static inline u32 mpc83xx_spi_read_reg(__be32 __iomem * reg)
98	{
99	return in_be32(reg);
100	}
101
102	#define MPC83XX_SPI_RX_BUF(type) \
103	void mpc83xx_spi_rx_buf_##type(u32 data, struct mpc83xx_spi *mpc83xx_spi) \
104	{ \
105	type * rx = mpc83xx_spi->rx; \
106	*rx++ = (type)data; \
107	mpc83xx_spi->rx = rx; \
108	}
109
110	#define MPC83XX_SPI_TX_BUF(type) \
111	u32 mpc83xx_spi_tx_buf_##type(struct mpc83xx_spi *mpc83xx_spi) \
112	{ \
113	u32 data; \
114	const type * tx = mpc83xx_spi->tx; \
4b1badf5 DB	115	if (!tx) \
4b1badf5 DB	116	return 0; \
ccf06998 KG	117	data = *tx++; \
	118	mpc83xx_spi->tx = tx; \
	119	return data; \
	120	}
	121
	122	MPC83XX_SPI_RX_BUF(u8)
	123	MPC83XX_SPI_RX_BUF(u16)
	124	MPC83XX_SPI_RX_BUF(u32)
	125	MPC83XX_SPI_TX_BUF(u8)
	126	MPC83XX_SPI_TX_BUF(u16)
	127	MPC83XX_SPI_TX_BUF(u32)
	128
	129	static void mpc83xx_spi_chipselect(struct spi_device *spi, int value)
	130	{
	131	struct mpc83xx_spi *mpc83xx_spi;
	132	u8 pol = spi->mode & SPI_CS_HIGH ? 1 : 0;
	133
	134	mpc83xx_spi = spi_master_get_devdata(spi->master);
	135
	136	if (value == BITBANG_CS_INACTIVE) {
	137	if (mpc83xx_spi->deactivate_cs)
	138	mpc83xx_spi->deactivate_cs(spi->chip_select, pol);
	139	}
	140
	141	if (value == BITBANG_CS_ACTIVE) {
	142	u32 regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
	143	u32 len = spi->bits_per_word;
	144	if (len == 32)
	145	len = 0;
	146	else
	147	len = len - 1;
	148
	149	/* mask out bits we are going to set */
	150	regval &= ~0x38ff0000;
	151
	152	if (spi->mode & SPI_CPHA)
	153	regval \|= SPMODE_CP_BEGIN_EDGECLK;
	154	if (spi->mode & SPI_CPOL)
	155	regval \|= SPMODE_CI_INACTIVEHIGH;
	156
	157	regval \|= SPMODE_LEN(len);
	158
	159	if ((mpc83xx_spi->sysclk / spi->max_speed_hz) >= 64) {
	160	u8 pm = mpc83xx_spi->sysclk / (spi->max_speed_hz * 64);
	161	regval \|= SPMODE_PM(pm) \| SPMODE_DIV16;
	162	} else {
	163	u8 pm = mpc83xx_spi->sysclk / (spi->max_speed_hz * 4);
	164	regval \|= SPMODE_PM(pm);
	165	}
	166
	167	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
	168	if (mpc83xx_spi->activate_cs)
	169	mpc83xx_spi->activate_cs(spi->chip_select, pol);
	170	}
	171	}
	172
	173	static
	174	int mpc83xx_spi_setup_transfer(struct spi_device spi, struct spi_transfer t)
	175	{
	176	struct mpc83xx_spi *mpc83xx_spi;
	177	u32 regval;
	178	u8 bits_per_word;
	179	u32 hz;
	180
181	mpc83xx_spi = spi_master_get_devdata(spi->master);
182
183	if (t) {
184	bits_per_word = t->bits_per_word;
185	hz = t->speed_hz;
186	} else {
187	bits_per_word = 0;
188	hz = 0;
189	}
190
191	/* spi_transfer level calls that work per-word */
192	if (!bits_per_word)
193	bits_per_word = spi->bits_per_word;
194
195	/* Make sure its a bit width we support [4..16, 32] */
196	if ((bits_per_word < 4)
197	\|\| ((bits_per_word > 16) && (bits_per_word != 32)))
198	return -EINVAL;
199
200	if (bits_per_word <= 8) {
201	mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
202	mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;
203	} else if (bits_per_word <= 16) {
204	mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u16;
205	mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u16;
206	} else if (bits_per_word <= 32) {
207	mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u32;
208	mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u32;
209	} else
210	return -EINVAL;
211
212	/* nsecs = (clock period)/2 */
213	if (!hz)
214	hz = spi->max_speed_hz;
215	mpc83xx_spi->nsecs = (1000000000 / 2) / hz;
216	if (mpc83xx_spi->nsecs > MAX_UDELAY_MS * 1000)
217	return -EINVAL;
218
219	if (bits_per_word == 32)
220	bits_per_word = 0;
221	else
222	bits_per_word = bits_per_word - 1;
223
224	regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
225
226	/* Mask out bits_per_wordgth */
227	regval &= 0xff0fffff;
228	regval \|= SPMODE_LEN(bits_per_word);
229
230	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
231
232	return 0;
233	}
234
dccd573b DB	235	/* the spi->mode bits understood by this driver: */
	236	#define MODEBITS (SPI_CPOL \| SPI_CPHA \| SPI_CS_HIGH)
	237
ccf06998 KG	238	static int mpc83xx_spi_setup(struct spi_device *spi)
	239	{
	240	struct spi_bitbang *bitbang;
	241	struct mpc83xx_spi *mpc83xx_spi;
	242	int retval;
	243
dccd573b DB	244	if (spi->mode & ~MODEBITS) {
	245	dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
	246	spi->mode & ~MODEBITS);
	247	return -EINVAL;
	248	}
	249
ccf06998 KG	250	if (!spi->max_speed_hz)
	251	return -EINVAL;
	252
	253	bitbang = spi_master_get_devdata(spi->master);
	254	mpc83xx_spi = spi_master_get_devdata(spi->master);
	255
	256	if (!spi->bits_per_word)
	257	spi->bits_per_word = 8;
	258
	259	retval = mpc83xx_spi_setup_transfer(spi, NULL);
	260	if (retval < 0)
	261	return retval;
	262
	263	dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec\n",
	264	__FUNCTION__, spi->mode & (SPI_CPOL \| SPI_CPHA),
	265	spi->bits_per_word, 2 * mpc83xx_spi->nsecs);
	266
	267	/* NOTE we _need_ to call chipselect() early, ideally with adapter
	268	* setup, unless the hardware defaults cooperate to avoid confusion
	269	* between normal (active low) and inverted chipselects.
	270	*/
	271
	272	/* deselect chip (low or high) */
	273	spin_lock(&bitbang->lock);
	274	if (!bitbang->busy) {
	275	bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
	276	ndelay(mpc83xx_spi->nsecs);
	277	}
	278	spin_unlock(&bitbang->lock);
	279
	280	return 0;
	281	}
	282
	283	static int mpc83xx_spi_bufs(struct spi_device spi, struct spi_transfer t)
	284	{
	285	struct mpc83xx_spi *mpc83xx_spi;
	286	u32 word;
	287
	288	mpc83xx_spi = spi_master_get_devdata(spi->master);
	289
	290	mpc83xx_spi->tx = t->tx_buf;
	291	mpc83xx_spi->rx = t->rx_buf;
	292	mpc83xx_spi->count = t->len;
	293	INIT_COMPLETION(mpc83xx_spi->done);
	294
	295	/* enable rx ints */
	296	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, SPIM_NE);
	297
	298	/* transmit word */
	299	word = mpc83xx_spi->get_tx(mpc83xx_spi);
	300	mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit, word);
	301
	302	wait_for_completion(&mpc83xx_spi->done);
	303
	304	/* disable rx ints */
	305	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0);
	306
	307	return t->len - mpc83xx_spi->count;
	308	}
	309
7d12e780	310	irqreturn_t mpc83xx_spi_irq(s32 irq, void *context_data)
ccf06998 KG	311	{
	312	struct mpc83xx_spi *mpc83xx_spi = context_data;
	313	u32 event;
	314	irqreturn_t ret = IRQ_NONE;
	315
	316	/* Get interrupt events(tx/rx) */
	317	event = mpc83xx_spi_read_reg(&mpc83xx_spi->base->event);
	318
	319	/* We need handle RX first */
	320	if (event & SPIE_NE) {
	321	u32 rx_data = mpc83xx_spi_read_reg(&mpc83xx_spi->base->receive);
	322
	323	if (mpc83xx_spi->rx)
	324	mpc83xx_spi->get_rx(rx_data, mpc83xx_spi);
	325
	326	ret = IRQ_HANDLED;
	327	}
	328
	329	if ((event & SPIE_NF) == 0)
	330	/* spin until TX is done */
	331	while (((event =
	332	mpc83xx_spi_read_reg(&mpc83xx_spi->base->event)) &
	333	SPIE_NF) == 0)
	334	cpu_relax();
	335
	336	mpc83xx_spi->count -= 1;
	337	if (mpc83xx_spi->count) {
	338	if (mpc83xx_spi->tx) {
	339	u32 word = mpc83xx_spi->get_tx(mpc83xx_spi);
	340	mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit,
	341	word);
	342	}
	343	} else {
	344	complete(&mpc83xx_spi->done);
	345	}
	346
	347	/* Clear the events */
	348	mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, event);
	349
	350	return ret;
	351	}
	352
	353	static int __init mpc83xx_spi_probe(struct platform_device *dev)
	354	{
	355	struct spi_master *master;
	356	struct mpc83xx_spi *mpc83xx_spi;
	357	struct fsl_spi_platform_data *pdata;
	358	struct resource *r;
	359	u32 regval;
	360	int ret = 0;
	361
	362	/* Get resources(memory, IRQ) associated with the device */
	363	master = spi_alloc_master(&dev->dev, sizeof(struct mpc83xx_spi));
	364
	365	if (master == NULL) {
	366	ret = -ENOMEM;
	367	goto err;
	368	}
	369
	370	platform_set_drvdata(dev, master);
	371	pdata = dev->dev.platform_data;
	372
	373	if (pdata == NULL) {
	374	ret = -ENODEV;
375	goto free_master;
376	}
377
378	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
379	if (r == NULL) {
380	ret = -ENODEV;
381	goto free_master;
382	}
383
384	mpc83xx_spi = spi_master_get_devdata(master);
385	mpc83xx_spi->bitbang.master = spi_master_get(master);
386	mpc83xx_spi->bitbang.chipselect = mpc83xx_spi_chipselect;
387	mpc83xx_spi->bitbang.setup_transfer = mpc83xx_spi_setup_transfer;
388	mpc83xx_spi->bitbang.txrx_bufs = mpc83xx_spi_bufs;
389	mpc83xx_spi->sysclk = pdata->sysclk;
390	mpc83xx_spi->activate_cs = pdata->activate_cs;
391	mpc83xx_spi->deactivate_cs = pdata->deactivate_cs;
392	mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
393	mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;
394
395	mpc83xx_spi->bitbang.master->setup = mpc83xx_spi_setup;
396	init_completion(&mpc83xx_spi->done);
397
398	mpc83xx_spi->base = ioremap(r->start, r->end - r->start + 1);
399	if (mpc83xx_spi->base == NULL) {
400	ret = -ENOMEM;
401	goto put_master;
402	}
403
404	mpc83xx_spi->irq = platform_get_irq(dev, 0);
405
406	if (mpc83xx_spi->irq < 0) {
407	ret = -ENXIO;
408	goto unmap_io;
409	}
410
411	/* Register for SPI Interrupt */
412	ret = request_irq(mpc83xx_spi->irq, mpc83xx_spi_irq,
413	0, "mpc83xx_spi", mpc83xx_spi);
414
415	if (ret != 0)
416	goto unmap_io;
417
418	master->bus_num = pdata->bus_num;
419	master->num_chipselect = pdata->max_chipselect;
420
421	/* SPI controller initializations */
422	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0);
423	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0);
424	mpc83xx_spi_write_reg(&mpc83xx_spi->base->command, 0);
425	mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, 0xffffffff);
426
427	/* Enable SPI interface */
428	regval = pdata->initial_spmode \| SPMODE_INIT_VAL \| SPMODE_ENABLE;
429	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
430
431	ret = spi_bitbang_start(&mpc83xx_spi->bitbang);
432
433	if (ret != 0)
434	goto free_irq;
435
436	printk(KERN_INFO
437	"%s: MPC83xx SPI Controller driver at 0x%p (irq = %d)\n",
438	dev->dev.bus_id, mpc83xx_spi->base, mpc83xx_spi->irq);
439
440	return ret;
441
442	free_irq:
443	free_irq(mpc83xx_spi->irq, mpc83xx_spi);
444	unmap_io:
445	iounmap(mpc83xx_spi->base);
446	put_master:
447	spi_master_put(master);
448	free_master:
449	kfree(master);
450	err:
451	return ret;
452	}
453
454	static int __devexit mpc83xx_spi_remove(struct platform_device *dev)
455	{
456	struct mpc83xx_spi *mpc83xx_spi;
457	struct spi_master *master;
458
459	master = platform_get_drvdata(dev);
460	mpc83xx_spi = spi_master_get_devdata(master);
461
462	spi_bitbang_stop(&mpc83xx_spi->bitbang);
463	free_irq(mpc83xx_spi->irq, mpc83xx_spi);
464	iounmap(mpc83xx_spi->base);
465	spi_master_put(mpc83xx_spi->bitbang.master);
466
467	return 0;
468	}
469
470	static struct platform_driver mpc83xx_spi_driver = {
471	.probe = mpc83xx_spi_probe,
472	.remove = __devexit_p(mpc83xx_spi_remove),
473	.driver = {
474	.name = "mpc83xx_spi",
475	},
476	};
477
478	static int __init mpc83xx_spi_init(void)
479	{
480	return platform_driver_register(&mpc83xx_spi_driver);
481	}
482
483	static void __exit mpc83xx_spi_exit(void)
484	{
485	platform_driver_unregister(&mpc83xx_spi_driver);
486	}
487
488	module_init(mpc83xx_spi_init);
489	module_exit(mpc83xx_spi_exit);
490
491	MODULE_AUTHOR("Kumar Gala");
492	MODULE_DESCRIPTION("Simple MPC83xx SPI Driver");
493	MODULE_LICENSE("GPL");