[mirror_ubuntu-zesty-kernel.git] / drivers / spi / spi-altera.c

/*
 * Altera SPI driver
 *
 * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
 *
 * Based on spi_s3c24xx.c, which is:
 * Copyright (c) 2006 Ben Dooks
 * Copyright (c) 2006 Simtec Electronics
 *	Ben Dooks <ben@simtec.co.uk>
 *
 * 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/init.h>
#include <linux/interrupt.h>
#include <linux/errno.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi_bitbang.h>
#include <linux/io.h>
#include <linux/of.h>

#define DRV_NAME "spi_altera"

#define ALTERA_SPI_RXDATA	0
#define ALTERA_SPI_TXDATA	4
#define ALTERA_SPI_STATUS	8
#define ALTERA_SPI_CONTROL	12
#define ALTERA_SPI_SLAVE_SEL	20

#define ALTERA_SPI_STATUS_ROE_MSK	0x8
#define ALTERA_SPI_STATUS_TOE_MSK	0x10
#define ALTERA_SPI_STATUS_TMT_MSK	0x20
#define ALTERA_SPI_STATUS_TRDY_MSK	0x40
#define ALTERA_SPI_STATUS_RRDY_MSK	0x80
#define ALTERA_SPI_STATUS_E_MSK		0x100

#define ALTERA_SPI_CONTROL_IROE_MSK	0x8
#define ALTERA_SPI_CONTROL_ITOE_MSK	0x10
#define ALTERA_SPI_CONTROL_ITRDY_MSK	0x40
#define ALTERA_SPI_CONTROL_IRRDY_MSK	0x80
#define ALTERA_SPI_CONTROL_IE_MSK	0x100
#define ALTERA_SPI_CONTROL_SSO_MSK	0x400

struct altera_spi {
	/* bitbang has to be first */
	struct spi_bitbang bitbang;
	struct completion done;

	void __iomem *base;
	int irq;
	int len;
	int count;
	int bytes_per_word;
	unsigned long imr;

	/* data buffers */
	const unsigned char *tx;
	unsigned char *rx;
};

static inline struct altera_spi *altera_spi_to_hw(struct spi_device *sdev)
{
	return spi_master_get_devdata(sdev->master);
}

static void altera_spi_chipsel(struct spi_device *spi, int value)
{
	struct altera_spi *hw = altera_spi_to_hw(spi);

	if (spi->mode & SPI_CS_HIGH) {
		switch (value) {
		case BITBANG_CS_INACTIVE:
			writel(1 << spi->chip_select,
			       hw->base + ALTERA_SPI_SLAVE_SEL);
			hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
			writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
			break;

		case BITBANG_CS_ACTIVE:
			hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
			writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
			writel(0, hw->base + ALTERA_SPI_SLAVE_SEL);
			break;
		}
	} else {
		switch (value) {
		case BITBANG_CS_INACTIVE:
			hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
			writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
			break;

		case BITBANG_CS_ACTIVE:
			writel(1 << spi->chip_select,
			       hw->base + ALTERA_SPI_SLAVE_SEL);
			hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
			writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
			break;
		}
	}
}

static inline unsigned int hw_txbyte(struct altera_spi *hw, int count)
{
	if (hw->tx) {
		switch (hw->bytes_per_word) {
		case 1:
			return hw->tx[count];
		case 2:
			return (hw->tx[count * 2]
				| (hw->tx[count * 2 + 1] << 8));
		}
	}
	return 0;
}

static int altera_spi_txrx(struct spi_device *spi, struct spi_transfer *t)
{
	struct altera_spi *hw = altera_spi_to_hw(spi);

	hw->tx = t->tx_buf;
	hw->rx = t->rx_buf;
	hw->count = 0;
	hw->bytes_per_word = DIV_ROUND_UP(t->bits_per_word, 8);
	hw->len = t->len / hw->bytes_per_word;

	if (hw->irq >= 0) {
		/* enable receive interrupt */
		hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK;
		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);

		/* send the first byte */
		writel(hw_txbyte(hw, 0), hw->base + ALTERA_SPI_TXDATA);

		wait_for_completion(&hw->done);
		/* disable receive interrupt */
		hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
		writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
	} else {
		while (hw->count < hw->len) {
			unsigned int rxd;

			writel(hw_txbyte(hw, hw->count),
			       hw->base + ALTERA_SPI_TXDATA);

			while (!(readl(hw->base + ALTERA_SPI_STATUS) &
				 ALTERA_SPI_STATUS_RRDY_MSK))
				cpu_relax();

			rxd = readl(hw->base + ALTERA_SPI_RXDATA);
			if (hw->rx) {
				switch (hw->bytes_per_word) {
				case 1:
					hw->rx[hw->count] = rxd;
					break;
				case 2:
					hw->rx[hw->count * 2] = rxd;
					hw->rx[hw->count * 2 + 1] = rxd >> 8;
					break;
				}
			}

			hw->count++;
		}
	}

	return hw->count * hw->bytes_per_word;
}

static irqreturn_t altera_spi_irq(int irq, void *dev)
{
	struct altera_spi *hw = dev;
	unsigned int rxd;

	rxd = readl(hw->base + ALTERA_SPI_RXDATA);
	if (hw->rx) {
		switch (hw->bytes_per_word) {
		case 1:
			hw->rx[hw->count] = rxd;
			break;
		case 2:
			hw->rx[hw->count * 2] = rxd;
			hw->rx[hw->count * 2 + 1] = rxd >> 8;
			break;
		}
	}

	hw->count++;

	if (hw->count < hw->len)
		writel(hw_txbyte(hw, hw->count), hw->base + ALTERA_SPI_TXDATA);
	else
		complete(&hw->done);

	return IRQ_HANDLED;
}

static int altera_spi_probe(struct platform_device *pdev)
{
	struct altera_spi_platform_data *platp = dev_get_platdata(&pdev->dev);
	struct altera_spi *hw;
	struct spi_master *master;
	struct resource *res;
	int err = -ENODEV;

	master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
	if (!master)
		return err;

	/* setup the master state. */
	master->bus_num = pdev->id;
	master->num_chipselect = 16;
	master->mode_bits = SPI_CS_HIGH;

	hw = spi_master_get_devdata(master);
	platform_set_drvdata(pdev, hw);

	/* setup the state for the bitbang driver */
	hw->bitbang.master = spi_master_get(master);
	if (!hw->bitbang.master)
		return err;
	hw->bitbang.chipselect = altera_spi_chipsel;
	hw->bitbang.txrx_bufs = altera_spi_txrx;

	/* find and map our resources */
	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	hw->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(hw->base)) {
		err = PTR_ERR(hw->base);
		goto exit;
	}
	/* program defaults into the registers */
	hw->imr = 0;		/* disable spi interrupts */
	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
	writel(0, hw->base + ALTERA_SPI_STATUS);	/* clear status reg */
	if (readl(hw->base + ALTERA_SPI_STATUS) & ALTERA_SPI_STATUS_RRDY_MSK)
		readl(hw->base + ALTERA_SPI_RXDATA);	/* flush rxdata */
	/* irq is optional */
	hw->irq = platform_get_irq(pdev, 0);
	if (hw->irq >= 0) {
		init_completion(&hw->done);
		err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0,
				       pdev->name, hw);
		if (err)
			goto exit;
	}
	/* find platform data */
	if (!platp)
		hw->bitbang.master->dev.of_node = pdev->dev.of_node;

	/* register our spi controller */
	err = spi_bitbang_start(&hw->bitbang);
	if (err)
		goto exit;
	dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);

	return 0;
exit:
	spi_master_put(master);
	return err;
}

static int altera_spi_remove(struct platform_device *dev)
{
	struct altera_spi *hw = platform_get_drvdata(dev);
	struct spi_master *master = hw->bitbang.master;

	spi_bitbang_stop(&hw->bitbang);
	spi_master_put(master);
	return 0;
}

#ifdef CONFIG_OF
static const struct of_device_id altera_spi_match[] = {
	{ .compatible = "ALTR,spi-1.0", },
	{ .compatible = "altr,spi-1.0", },
	{},
};
MODULE_DEVICE_TABLE(of, altera_spi_match);
#endif /* CONFIG_OF */

static struct platform_driver altera_spi_driver = {
	.probe = altera_spi_probe,
	.remove = altera_spi_remove,
	.driver = {
		.name = DRV_NAME,
		.owner = THIS_MODULE,
		.pm = NULL,
		.of_match_table = of_match_ptr(altera_spi_match),
	},
};
module_platform_driver(altera_spi_driver);

MODULE_DESCRIPTION("Altera SPI driver");
MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRV_NAME);
Commit	Line	Data
0b782531 TC	1	/*
	2	* Altera SPI driver
	3	*
	4	* Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
	5	*
	6	* Based on spi_s3c24xx.c, which is:
	7	* Copyright (c) 2006 Ben Dooks
	8	* Copyright (c) 2006 Simtec Electronics
	9	* Ben Dooks <ben@simtec.co.uk>
	10	*
	11	* This program is free software; you can redistribute it and/or modify
	12	* it under the terms of the GNU General Public License version 2 as
	13	* published by the Free Software Foundation.
	14	*/
	15
	16	#include <linux/init.h>
	17	#include <linux/interrupt.h>
	18	#include <linux/errno.h>
d7614de4	19	#include <linux/module.h>
0b782531 TC	20	#include <linux/platform_device.h>
	21	#include <linux/spi/spi.h>
	22	#include <linux/spi/spi_bitbang.h>
	23	#include <linux/io.h>
	24	#include <linux/of.h>
	25
	26	#define DRV_NAME "spi_altera"
	27
	28	#define ALTERA_SPI_RXDATA 0
	29	#define ALTERA_SPI_TXDATA 4
	30	#define ALTERA_SPI_STATUS 8
	31	#define ALTERA_SPI_CONTROL 12
	32	#define ALTERA_SPI_SLAVE_SEL 20
	33
	34	#define ALTERA_SPI_STATUS_ROE_MSK 0x8
	35	#define ALTERA_SPI_STATUS_TOE_MSK 0x10
	36	#define ALTERA_SPI_STATUS_TMT_MSK 0x20
	37	#define ALTERA_SPI_STATUS_TRDY_MSK 0x40
	38	#define ALTERA_SPI_STATUS_RRDY_MSK 0x80
	39	#define ALTERA_SPI_STATUS_E_MSK 0x100
	40
	41	#define ALTERA_SPI_CONTROL_IROE_MSK 0x8
	42	#define ALTERA_SPI_CONTROL_ITOE_MSK 0x10
	43	#define ALTERA_SPI_CONTROL_ITRDY_MSK 0x40
	44	#define ALTERA_SPI_CONTROL_IRRDY_MSK 0x80
	45	#define ALTERA_SPI_CONTROL_IE_MSK 0x100
	46	#define ALTERA_SPI_CONTROL_SSO_MSK 0x400
	47
	48	struct altera_spi {
	49	/* bitbang has to be first */
	50	struct spi_bitbang bitbang;
	51	struct completion done;
	52
	53	void __iomem *base;
	54	int irq;
	55	int len;
	56	int count;
	57	int bytes_per_word;
	58	unsigned long imr;
	59
	60	/* data buffers */
	61	const unsigned char *tx;
	62	unsigned char *rx;
	63	};
	64
	65	static inline struct altera_spi altera_spi_to_hw(struct spi_device sdev)
	66	{
	67	return spi_master_get_devdata(sdev->master);
	68	}
	69
	70	static void altera_spi_chipsel(struct spi_device *spi, int value)
	71	{
	72	struct altera_spi *hw = altera_spi_to_hw(spi);
	73
	74	if (spi->mode & SPI_CS_HIGH) {
	75	switch (value) {
	76	case BITBANG_CS_INACTIVE:
	77	writel(1 << spi->chip_select,
	78	hw->base + ALTERA_SPI_SLAVE_SEL);
	79	hw->imr \|= ALTERA_SPI_CONTROL_SSO_MSK;
	80	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
	81	break;
	82
	83	case BITBANG_CS_ACTIVE:
84	hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
85	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
86	writel(0, hw->base + ALTERA_SPI_SLAVE_SEL);
87	break;
88	}
89	} else {
90	switch (value) {
91	case BITBANG_CS_INACTIVE:
92	hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
93	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
94	break;
95
96	case BITBANG_CS_ACTIVE:
97	writel(1 << spi->chip_select,
98	hw->base + ALTERA_SPI_SLAVE_SEL);
99	hw->imr \|= ALTERA_SPI_CONTROL_SSO_MSK;
100	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
101	break;
102	}
103	}
104	}
105
0b782531 TC	106	static inline unsigned int hw_txbyte(struct altera_spi *hw, int count)
	107	{
	108	if (hw->tx) {
	109	switch (hw->bytes_per_word) {
	110	case 1:
	111	return hw->tx[count];
	112	case 2:
	113	return (hw->tx[count * 2]
	114	\| (hw->tx[count * 2 + 1] << 8));
	115	}
	116	}
	117	return 0;
	118	}
	119
	120	static int altera_spi_txrx(struct spi_device spi, struct spi_transfer t)
	121	{
	122	struct altera_spi *hw = altera_spi_to_hw(spi);
	123
	124	hw->tx = t->tx_buf;
	125	hw->rx = t->rx_buf;
	126	hw->count = 0;
f073d37d	127	hw->bytes_per_word = DIV_ROUND_UP(t->bits_per_word, 8);
0b782531 TC	128	hw->len = t->len / hw->bytes_per_word;
	129
	130	if (hw->irq >= 0) {
	131	/* enable receive interrupt */
	132	hw->imr \|= ALTERA_SPI_CONTROL_IRRDY_MSK;
	133	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
	134
	135	/* send the first byte */
	136	writel(hw_txbyte(hw, 0), hw->base + ALTERA_SPI_TXDATA);
	137
	138	wait_for_completion(&hw->done);
	139	/* disable receive interrupt */
	140	hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
	141	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
	142	} else {
72be0ee4	143	while (hw->count < hw->len) {
0b782531 TC	144	unsigned int rxd;
0b782531 TC	145
72be0ee4 AL	146	writel(hw_txbyte(hw, hw->count),
	147	hw->base + ALTERA_SPI_TXDATA);
	148
0b782531 TC	149	while (!(readl(hw->base + ALTERA_SPI_STATUS) &
	150	ALTERA_SPI_STATUS_RRDY_MSK))
	151	cpu_relax();
	152
	153	rxd = readl(hw->base + ALTERA_SPI_RXDATA);
	154	if (hw->rx) {
	155	switch (hw->bytes_per_word) {
	156	case 1:
	157	hw->rx[hw->count] = rxd;
	158	break;
	159	case 2:
	160	hw->rx[hw->count * 2] = rxd;
	161	hw->rx[hw->count * 2 + 1] = rxd >> 8;
	162	break;
	163	}
	164	}
	165
	166	hw->count++;
0b782531	167	}
0b782531 TC	168	}
	169
	170	return hw->count * hw->bytes_per_word;
	171	}
	172
	173	static irqreturn_t altera_spi_irq(int irq, void *dev)
	174	{
	175	struct altera_spi *hw = dev;
	176	unsigned int rxd;
	177
	178	rxd = readl(hw->base + ALTERA_SPI_RXDATA);
	179	if (hw->rx) {
	180	switch (hw->bytes_per_word) {
	181	case 1:
	182	hw->rx[hw->count] = rxd;
	183	break;
	184	case 2:
	185	hw->rx[hw->count * 2] = rxd;
	186	hw->rx[hw->count * 2 + 1] = rxd >> 8;
	187	break;
	188	}
	189	}
	190
	191	hw->count++;
	192
	193	if (hw->count < hw->len)
	194	writel(hw_txbyte(hw, hw->count), hw->base + ALTERA_SPI_TXDATA);
	195	else
	196	complete(&hw->done);
	197
	198	return IRQ_HANDLED;
	199	}
	200
fd4a319b	201	static int altera_spi_probe(struct platform_device *pdev)
0b782531	202	{
8074cf06	203	struct altera_spi_platform_data *platp = dev_get_platdata(&pdev->dev);
0b782531 TC	204	struct altera_spi *hw;
	205	struct spi_master *master;
	206	struct resource *res;
	207	int err = -ENODEV;
	208
	209	master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
	210	if (!master)
	211	return err;
	212
	213	/* setup the master state. */
	214	master->bus_num = pdev->id;
	215	master->num_chipselect = 16;
	216	master->mode_bits = SPI_CS_HIGH;
0b782531 TC	217
	218	hw = spi_master_get_devdata(master);
	219	platform_set_drvdata(pdev, hw);
	220
	221	/* setup the state for the bitbang driver */
	222	hw->bitbang.master = spi_master_get(master);
	223	if (!hw->bitbang.master)
	224	return err;
0b782531 TC	225	hw->bitbang.chipselect = altera_spi_chipsel;
	226	hw->bitbang.txrx_bufs = altera_spi_txrx;
	227
	228	/* find and map our resources */
	229	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
b3136f8f JL	230	hw->base = devm_ioremap_resource(&pdev->dev, res);
	231	if (IS_ERR(hw->base)) {
	232	err = PTR_ERR(hw->base);
	233	goto exit;
	234	}
0b782531 TC	235	/* program defaults into the registers */
	236	hw->imr = 0; /* disable spi interrupts */
	237	writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
	238	writel(0, hw->base + ALTERA_SPI_STATUS); /* clear status reg */
	239	if (readl(hw->base + ALTERA_SPI_STATUS) & ALTERA_SPI_STATUS_RRDY_MSK)
	240	readl(hw->base + ALTERA_SPI_RXDATA); /* flush rxdata */
	241	/* irq is optional */
	242	hw->irq = platform_get_irq(pdev, 0);
	243	if (hw->irq >= 0) {
	244	init_completion(&hw->done);
	245	err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0,
	246	pdev->name, hw);
	247	if (err)
	248	goto exit;
	249	}
	250	/* find platform data */
	251	if (!platp)
	252	hw->bitbang.master->dev.of_node = pdev->dev.of_node;
	253
	254	/* register our spi controller */
	255	err = spi_bitbang_start(&hw->bitbang);
	256	if (err)
	257	goto exit;
	258	dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
	259
	260	return 0;
0b782531	261	exit:
0b782531 TC	262	spi_master_put(master);
	263	return err;
	264	}
	265
fd4a319b	266	static int altera_spi_remove(struct platform_device *dev)
0b782531 TC	267	{
	268	struct altera_spi *hw = platform_get_drvdata(dev);
	269	struct spi_master *master = hw->bitbang.master;
	270
	271	spi_bitbang_stop(&hw->bitbang);
0b782531 TC	272	spi_master_put(master);
	273	return 0;
	274	}
	275
	276	#ifdef CONFIG_OF
	277	static const struct of_device_id altera_spi_match[] = {
	278	{ .compatible = "ALTR,spi-1.0", },
13960b47	279	{ .compatible = "altr,spi-1.0", },
0b782531 TC	280	{},
	281	};
	282	MODULE_DEVICE_TABLE(of, altera_spi_match);
0b782531 TC	283	#endif /* CONFIG_OF */
	284
	285	static struct platform_driver altera_spi_driver = {
	286	.probe = altera_spi_probe,
fd4a319b	287	.remove = altera_spi_remove,
0b782531 TC	288	.driver = {
	289	.name = DRV_NAME,
	290	.owner = THIS_MODULE,
	291	.pm = NULL,
89f98dc5	292	.of_match_table = of_match_ptr(altera_spi_match),
0b782531 TC	293	},
0b782531 TC	294	};
940ab889	295	module_platform_driver(altera_spi_driver);
0b782531 TC	296
	297	MODULE_DESCRIPTION("Altera SPI driver");
	298	MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
	299	MODULE_LICENSE("GPL");
	300	MODULE_ALIAS("platform:" DRV_NAME);