[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);
			if (pm > 0x0f) {
				printk(KERN_WARNING "MPC83xx SPI: SPICLK can't be less then a SYSCLK/1024!\n"
						"Requested SPICLK is %d Hz. Will use %d Hz instead.\n",
						spi->max_speed_hz, mpc83xx_spi->sysclk / 1024);
				pm = 0x0f;
			}
			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);
698ca47e CW	161	if (pm > 0x0f) {
	162	printk(KERN_WARNING "MPC83xx SPI: SPICLK can't be less then a SYSCLK/1024!\n"
	163	"Requested SPICLK is %d Hz. Will use %d Hz instead.\n",
	164	spi->max_speed_hz, mpc83xx_spi->sysclk / 1024);
	165	pm = 0x0f;
	166	}
ccf06998 KG	167	regval \|= SPMODE_PM(pm) \| SPMODE_DIV16;
	168	} else {
	169	u8 pm = mpc83xx_spi->sysclk / (spi->max_speed_hz * 4);
	170	regval \|= SPMODE_PM(pm);
	171	}
	172
	173	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
	174	if (mpc83xx_spi->activate_cs)
	175	mpc83xx_spi->activate_cs(spi->chip_select, pol);
	176	}
	177	}
	178
	179	static
	180	int mpc83xx_spi_setup_transfer(struct spi_device spi, struct spi_transfer t)
	181	{
	182	struct mpc83xx_spi *mpc83xx_spi;
	183	u32 regval;
	184	u8 bits_per_word;
	185	u32 hz;
	186
	187	mpc83xx_spi = spi_master_get_devdata(spi->master);
	188
	189	if (t) {
	190	bits_per_word = t->bits_per_word;
	191	hz = t->speed_hz;
	192	} else {
	193	bits_per_word = 0;
	194	hz = 0;
	195	}
	196
	197	/* spi_transfer level calls that work per-word */
	198	if (!bits_per_word)
	199	bits_per_word = spi->bits_per_word;
	200
	201	/* Make sure its a bit width we support [4..16, 32] */
	202	if ((bits_per_word < 4)
	203	\|\| ((bits_per_word > 16) && (bits_per_word != 32)))
	204	return -EINVAL;
	205
	206	if (bits_per_word <= 8) {
	207	mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
	208	mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;
	209	} else if (bits_per_word <= 16) {
	210	mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u16;
	211	mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u16;
	212	} else if (bits_per_word <= 32) {
	213	mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u32;
	214	mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u32;
	215	} else
	216	return -EINVAL;
	217
	218	/* nsecs = (clock period)/2 */
	219	if (!hz)
	220	hz = spi->max_speed_hz;
	221	mpc83xx_spi->nsecs = (1000000000 / 2) / hz;
	222	if (mpc83xx_spi->nsecs > MAX_UDELAY_MS * 1000)
	223	return -EINVAL;
	224
	225	if (bits_per_word == 32)
	226	bits_per_word = 0;
	227	else
	228	bits_per_word = bits_per_word - 1;
	229
	230	regval = mpc83xx_spi_read_reg(&mpc83xx_spi->base->mode);
231
232	/* Mask out bits_per_wordgth */
233	regval &= 0xff0fffff;
234	regval \|= SPMODE_LEN(bits_per_word);
235
236	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
237
238	return 0;
239	}
240
dccd573b DB	241	/* the spi->mode bits understood by this driver: */
	242	#define MODEBITS (SPI_CPOL \| SPI_CPHA \| SPI_CS_HIGH)
	243
ccf06998 KG	244	static int mpc83xx_spi_setup(struct spi_device *spi)
	245	{
	246	struct spi_bitbang *bitbang;
	247	struct mpc83xx_spi *mpc83xx_spi;
	248	int retval;
	249
dccd573b DB	250	if (spi->mode & ~MODEBITS) {
	251	dev_dbg(&spi->dev, "setup: unsupported mode bits %x\n",
	252	spi->mode & ~MODEBITS);
	253	return -EINVAL;
	254	}
	255
ccf06998 KG	256	if (!spi->max_speed_hz)
	257	return -EINVAL;
	258
	259	bitbang = spi_master_get_devdata(spi->master);
	260	mpc83xx_spi = spi_master_get_devdata(spi->master);
	261
	262	if (!spi->bits_per_word)
	263	spi->bits_per_word = 8;
	264
	265	retval = mpc83xx_spi_setup_transfer(spi, NULL);
	266	if (retval < 0)
	267	return retval;
	268
	269	dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec\n",
	270	__FUNCTION__, spi->mode & (SPI_CPOL \| SPI_CPHA),
	271	spi->bits_per_word, 2 * mpc83xx_spi->nsecs);
	272
	273	/* NOTE we _need_ to call chipselect() early, ideally with adapter
	274	* setup, unless the hardware defaults cooperate to avoid confusion
	275	* between normal (active low) and inverted chipselects.
	276	*/
	277
	278	/* deselect chip (low or high) */
	279	spin_lock(&bitbang->lock);
	280	if (!bitbang->busy) {
	281	bitbang->chipselect(spi, BITBANG_CS_INACTIVE);
	282	ndelay(mpc83xx_spi->nsecs);
	283	}
	284	spin_unlock(&bitbang->lock);
	285
	286	return 0;
	287	}
	288
	289	static int mpc83xx_spi_bufs(struct spi_device spi, struct spi_transfer t)
	290	{
	291	struct mpc83xx_spi *mpc83xx_spi;
	292	u32 word;
	293
	294	mpc83xx_spi = spi_master_get_devdata(spi->master);
	295
	296	mpc83xx_spi->tx = t->tx_buf;
	297	mpc83xx_spi->rx = t->rx_buf;
	298	mpc83xx_spi->count = t->len;
	299	INIT_COMPLETION(mpc83xx_spi->done);
	300
	301	/* enable rx ints */
	302	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, SPIM_NE);
	303
	304	/* transmit word */
	305	word = mpc83xx_spi->get_tx(mpc83xx_spi);
	306	mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit, word);
	307
	308	wait_for_completion(&mpc83xx_spi->done);
	309
	310	/* disable rx ints */
	311	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0);
	312
	313	return t->len - mpc83xx_spi->count;
	314	}
	315
7d12e780	316	irqreturn_t mpc83xx_spi_irq(s32 irq, void *context_data)
ccf06998 KG	317	{
	318	struct mpc83xx_spi *mpc83xx_spi = context_data;
	319	u32 event;
	320	irqreturn_t ret = IRQ_NONE;
	321
	322	/* Get interrupt events(tx/rx) */
	323	event = mpc83xx_spi_read_reg(&mpc83xx_spi->base->event);
	324
	325	/* We need handle RX first */
	326	if (event & SPIE_NE) {
	327	u32 rx_data = mpc83xx_spi_read_reg(&mpc83xx_spi->base->receive);
	328
	329	if (mpc83xx_spi->rx)
	330	mpc83xx_spi->get_rx(rx_data, mpc83xx_spi);
	331
	332	ret = IRQ_HANDLED;
	333	}
	334
	335	if ((event & SPIE_NF) == 0)
	336	/* spin until TX is done */
	337	while (((event =
	338	mpc83xx_spi_read_reg(&mpc83xx_spi->base->event)) &
	339	SPIE_NF) == 0)
	340	cpu_relax();
	341
	342	mpc83xx_spi->count -= 1;
	343	if (mpc83xx_spi->count) {
	344	if (mpc83xx_spi->tx) {
	345	u32 word = mpc83xx_spi->get_tx(mpc83xx_spi);
	346	mpc83xx_spi_write_reg(&mpc83xx_spi->base->transmit,
	347	word);
	348	}
	349	} else {
	350	complete(&mpc83xx_spi->done);
	351	}
	352
	353	/* Clear the events */
	354	mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, event);
	355
	356	return ret;
	357	}
	358
	359	static int __init mpc83xx_spi_probe(struct platform_device *dev)
	360	{
	361	struct spi_master *master;
	362	struct mpc83xx_spi *mpc83xx_spi;
	363	struct fsl_spi_platform_data *pdata;
	364	struct resource *r;
	365	u32 regval;
	366	int ret = 0;
	367
	368	/* Get resources(memory, IRQ) associated with the device */
	369	master = spi_alloc_master(&dev->dev, sizeof(struct mpc83xx_spi));
	370
	371	if (master == NULL) {
	372	ret = -ENOMEM;
	373	goto err;
	374	}
	375
	376	platform_set_drvdata(dev, master);
	377	pdata = dev->dev.platform_data;
	378
	379	if (pdata == NULL) {
	380	ret = -ENODEV;
381	goto free_master;
382	}
383
384	r = platform_get_resource(dev, IORESOURCE_MEM, 0);
385	if (r == NULL) {
386	ret = -ENODEV;
387	goto free_master;
388	}
389
390	mpc83xx_spi = spi_master_get_devdata(master);
391	mpc83xx_spi->bitbang.master = spi_master_get(master);
392	mpc83xx_spi->bitbang.chipselect = mpc83xx_spi_chipselect;
393	mpc83xx_spi->bitbang.setup_transfer = mpc83xx_spi_setup_transfer;
394	mpc83xx_spi->bitbang.txrx_bufs = mpc83xx_spi_bufs;
395	mpc83xx_spi->sysclk = pdata->sysclk;
396	mpc83xx_spi->activate_cs = pdata->activate_cs;
397	mpc83xx_spi->deactivate_cs = pdata->deactivate_cs;
398	mpc83xx_spi->get_rx = mpc83xx_spi_rx_buf_u8;
399	mpc83xx_spi->get_tx = mpc83xx_spi_tx_buf_u8;
400
401	mpc83xx_spi->bitbang.master->setup = mpc83xx_spi_setup;
402	init_completion(&mpc83xx_spi->done);
403
404	mpc83xx_spi->base = ioremap(r->start, r->end - r->start + 1);
405	if (mpc83xx_spi->base == NULL) {
406	ret = -ENOMEM;
407	goto put_master;
408	}
409
410	mpc83xx_spi->irq = platform_get_irq(dev, 0);
411
412	if (mpc83xx_spi->irq < 0) {
413	ret = -ENXIO;
414	goto unmap_io;
415	}
416
417	/* Register for SPI Interrupt */
418	ret = request_irq(mpc83xx_spi->irq, mpc83xx_spi_irq,
419	0, "mpc83xx_spi", mpc83xx_spi);
420
421	if (ret != 0)
422	goto unmap_io;
423
424	master->bus_num = pdata->bus_num;
425	master->num_chipselect = pdata->max_chipselect;
426
427	/* SPI controller initializations */
428	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, 0);
429	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mask, 0);
430	mpc83xx_spi_write_reg(&mpc83xx_spi->base->command, 0);
431	mpc83xx_spi_write_reg(&mpc83xx_spi->base->event, 0xffffffff);
432
433	/* Enable SPI interface */
434	regval = pdata->initial_spmode \| SPMODE_INIT_VAL \| SPMODE_ENABLE;
435	mpc83xx_spi_write_reg(&mpc83xx_spi->base->mode, regval);
436
437	ret = spi_bitbang_start(&mpc83xx_spi->bitbang);
438
439	if (ret != 0)
440	goto free_irq;
441
442	printk(KERN_INFO
443	"%s: MPC83xx SPI Controller driver at 0x%p (irq = %d)\n",
444	dev->dev.bus_id, mpc83xx_spi->base, mpc83xx_spi->irq);
445
446	return ret;
447
448	free_irq:
449	free_irq(mpc83xx_spi->irq, mpc83xx_spi);
450	unmap_io:
451	iounmap(mpc83xx_spi->base);
452	put_master:
453	spi_master_put(master);
454	free_master:
455	kfree(master);
456	err:
457	return ret;
458	}
459
460	static int __devexit mpc83xx_spi_remove(struct platform_device *dev)
461	{
462	struct mpc83xx_spi *mpc83xx_spi;
463	struct spi_master *master;
464
465	master = platform_get_drvdata(dev);
466	mpc83xx_spi = spi_master_get_devdata(master);
467
468	spi_bitbang_stop(&mpc83xx_spi->bitbang);
469	free_irq(mpc83xx_spi->irq, mpc83xx_spi);
470	iounmap(mpc83xx_spi->base);
471	spi_master_put(mpc83xx_spi->bitbang.master);
472
473	return 0;
474	}
475
476	static struct platform_driver mpc83xx_spi_driver = {
477	.probe = mpc83xx_spi_probe,
478	.remove = __devexit_p(mpc83xx_spi_remove),
479	.driver = {
480	.name = "mpc83xx_spi",
481	},
482	};
483
484	static int __init mpc83xx_spi_init(void)
485	{
486	return platform_driver_register(&mpc83xx_spi_driver);
487	}
488
489	static void __exit mpc83xx_spi_exit(void)
490	{
491	platform_driver_unregister(&mpc83xx_spi_driver);
492	}
493
494	module_init(mpc83xx_spi_init);
495	module_exit(mpc83xx_spi_exit);
496
497	MODULE_AUTHOR("Kumar Gala");
498	MODULE_DESCRIPTION("Simple MPC83xx SPI Driver");
499	MODULE_LICENSE("GPL");