[linux-2.6-block.git] / drivers / spi / spi-clps711x.c

/*
 *  CLPS711X SPI bus driver
 *
 *  Copyright (C) 2012-2016 Alexander Shiyan <shc_work@mail.ru>
 *
 * 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/io.h>
#include <linux/clk.h>
#include <linux/gpio.h>
#include <linux/module.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include <linux/mfd/syscon.h>
#include <linux/mfd/syscon/clps711x.h>
#include <linux/spi/spi.h>

#define DRIVER_NAME		"clps711x-spi"

#define SYNCIO_FRMLEN(x)	((x) << 8)
#define SYNCIO_TXFRMEN		(1 << 14)

struct spi_clps711x_data {
	void __iomem		*syncio;
	struct regmap		*syscon;
	struct clk		*spi_clk;

	u8			*tx_buf;
	u8			*rx_buf;
	unsigned int		bpw;
	int			len;
};

static int spi_clps711x_setup(struct spi_device *spi)
{
	if (!spi->controller_state) {
		int ret;

		ret = devm_gpio_request(&spi->master->dev, spi->cs_gpio,
					dev_name(&spi->master->dev));
		if (ret)
			return ret;

		spi->controller_state = spi;
	}

	/* We are expect that SPI-device is not selected */
	gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));

	return 0;
}

static int spi_clps711x_prepare_message(struct spi_master *master,
					struct spi_message *msg)
{
	struct spi_clps711x_data *hw = spi_master_get_devdata(master);
	struct spi_device *spi = msg->spi;

	/* Setup mode for transfer */
	return regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCKNSEN,
				  (spi->mode & SPI_CPHA) ?
				  SYSCON3_ADCCKNSEN : 0);
}

static int spi_clps711x_transfer_one(struct spi_master *master,
				     struct spi_device *spi,
				     struct spi_transfer *xfer)
{
	struct spi_clps711x_data *hw = spi_master_get_devdata(master);
	u8 data;

	clk_set_rate(hw->spi_clk, xfer->speed_hz ? : spi->max_speed_hz);

	hw->len = xfer->len;
	hw->bpw = xfer->bits_per_word;
	hw->tx_buf = (u8 *)xfer->tx_buf;
	hw->rx_buf = (u8 *)xfer->rx_buf;

	/* Initiate transfer */
	data = hw->tx_buf ? *hw->tx_buf++ : 0;
	writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN, hw->syncio);

	return 1;
}

static irqreturn_t spi_clps711x_isr(int irq, void *dev_id)
{
	struct spi_master *master = dev_id;
	struct spi_clps711x_data *hw = spi_master_get_devdata(master);
	u8 data;

	/* Handle RX */
	data = readb(hw->syncio);
	if (hw->rx_buf)
		*hw->rx_buf++ = data;

	/* Handle TX */
	if (--hw->len > 0) {
		data = hw->tx_buf ? *hw->tx_buf++ : 0;
		writel(data | SYNCIO_FRMLEN(hw->bpw) | SYNCIO_TXFRMEN,
		       hw->syncio);
	} else
		spi_finalize_current_transfer(master);

	return IRQ_HANDLED;
}

static int spi_clps711x_probe(struct platform_device *pdev)
{
	struct spi_clps711x_data *hw;
	struct spi_master *master;
	struct resource *res;
	int irq, ret;

	irq = platform_get_irq(pdev, 0);
	if (irq < 0)
		return irq;

	master = spi_alloc_master(&pdev->dev, sizeof(*hw));
	if (!master)
		return -ENOMEM;

	master->bus_num = -1;
	master->mode_bits = SPI_CPHA | SPI_CS_HIGH;
	master->bits_per_word_mask =  SPI_BPW_RANGE_MASK(1, 8);
	master->dev.of_node = pdev->dev.of_node;
	master->setup = spi_clps711x_setup;
	master->prepare_message = spi_clps711x_prepare_message;
	master->transfer_one = spi_clps711x_transfer_one;

	hw = spi_master_get_devdata(master);

	hw->spi_clk = devm_clk_get(&pdev->dev, NULL);
	if (IS_ERR(hw->spi_clk)) {
		ret = PTR_ERR(hw->spi_clk);
		goto err_out;
	}

	hw->syscon =
		syscon_regmap_lookup_by_compatible("cirrus,ep7209-syscon3");
	if (IS_ERR(hw->syscon)) {
		ret = PTR_ERR(hw->syscon);
		goto err_out;
	}

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	hw->syncio = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(hw->syncio)) {
		ret = PTR_ERR(hw->syncio);
		goto err_out;
	}

	/* Disable extended mode due hardware problems */
	regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCON, 0);

	/* Clear possible pending interrupt */
	readl(hw->syncio);

	ret = devm_request_irq(&pdev->dev, irq, spi_clps711x_isr, 0,
			       dev_name(&pdev->dev), master);
	if (ret)
		goto err_out;

	ret = devm_spi_register_master(&pdev->dev, master);
	if (!ret)
		return 0;

err_out:
	spi_master_put(master);

	return ret;
}

static const struct of_device_id clps711x_spi_dt_ids[] = {
	{ .compatible = "cirrus,ep7209-spi", },
	{ }
};
MODULE_DEVICE_TABLE(of, clps711x_spi_dt_ids);

static struct platform_driver clps711x_spi_driver = {
	.driver	= {
		.name	= DRIVER_NAME,
		.of_match_table = clps711x_spi_dt_ids,
	},
	.probe	= spi_clps711x_probe,
};
module_platform_driver(clps711x_spi_driver);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
MODULE_DESCRIPTION("CLPS711X SPI bus driver");
MODULE_ALIAS("platform:" DRIVER_NAME);
Commit	Line	Data
161b96c3 AS	1	/*
	2	* CLPS711X SPI bus driver
	3	*
6acaadc8	4	* Copyright (C) 2012-2016 Alexander Shiyan <shc_work@mail.ru>
161b96c3 AS	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*/
	11
	12	#include <linux/io.h>
	13	#include <linux/clk.h>
161b96c3	14	#include <linux/gpio.h>
161b96c3 AS	15	#include <linux/module.h>
	16	#include <linux/interrupt.h>
	17	#include <linux/platform_device.h>
3dc92594 AS	18	#include <linux/regmap.h>
	19	#include <linux/mfd/syscon.h>
	20	#include <linux/mfd/syscon/clps711x.h>
161b96c3	21	#include <linux/spi/spi.h>
161b96c3	22
6acaadc8	23	#define DRIVER_NAME "clps711x-spi"
161b96c3	24
3dc92594 AS	25	#define SYNCIO_FRMLEN(x) ((x) << 8)
	26	#define SYNCIO_TXFRMEN (1 << 14)
	27
161b96c3	28	struct spi_clps711x_data {
3dc92594 AS	29	void __iomem *syncio;
3dc92594 AS	30	struct regmap *syscon;
161b96c3	31	struct clk *spi_clk;
161b96c3 AS	32
	33	u8 *tx_buf;
	34	u8 *rx_buf;
8dda9d9a	35	unsigned int bpw;
161b96c3	36	int len;
161b96c3 AS	37	};
	38
	39	static int spi_clps711x_setup(struct spi_device *spi)
	40	{
6acaadc8 AS	41	if (!spi->controller_state) {
	42	int ret;
	43
	44	ret = devm_gpio_request(&spi->master->dev, spi->cs_gpio,
	45	dev_name(&spi->master->dev));
	46	if (ret)
	47	return ret;
	48
	49	spi->controller_state = spi;
	50	}
	51
161b96c3	52	/* We are expect that SPI-device is not selected */
3e9ea4b4	53	gpio_direction_output(spi->cs_gpio, !(spi->mode & SPI_CS_HIGH));
161b96c3 AS	54
	55	return 0;
	56	}
	57
bf5c2e27 AL	58	static int spi_clps711x_prepare_message(struct spi_master *master,
bf5c2e27 AL	59	struct spi_message *msg)
161b96c3	60	{
3dc92594	61	struct spi_clps711x_data *hw = spi_master_get_devdata(master);
8dda9d9a	62	struct spi_device *spi = msg->spi;
161b96c3	63
3dc92594 AS	64	/* Setup mode for transfer */
	65	return regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCKNSEN,
	66	(spi->mode & SPI_CPHA) ?
	67	SYSCON3_ADCCKNSEN : 0);
bf5c2e27	68	}
161b96c3	69
bf5c2e27 AL	70	static int spi_clps711x_transfer_one(struct spi_master *master,
	71	struct spi_device *spi,
	72	struct spi_transfer *xfer)
	73	{
	74	struct spi_clps711x_data *hw = spi_master_get_devdata(master);
	75	u8 data;
161b96c3	76
a5b4b234	77	clk_set_rate(hw->spi_clk, xfer->speed_hz ? : spi->max_speed_hz);
161b96c3	78
bf5c2e27	79	hw->len = xfer->len;
bed890b4	80	hw->bpw = xfer->bits_per_word;
bf5c2e27 AL	81	hw->tx_buf = (u8 *)xfer->tx_buf;
bf5c2e27 AL	82	hw->rx_buf = (u8 *)xfer->rx_buf;
161b96c3	83
bf5c2e27 AL	84	/* Initiate transfer */
bf5c2e27 AL	85	data = hw->tx_buf ? *hw->tx_buf++ : 0;
3dc92594 AS	86	writel(data \| SYNCIO_FRMLEN(hw->bpw) \| SYNCIO_TXFRMEN, hw->syncio);
3dc92594 AS	87
bf5c2e27	88	return 1;
161b96c3 AS	89	}
	90
	91	static irqreturn_t spi_clps711x_isr(int irq, void *dev_id)
	92	{
bf5c2e27 AL	93	struct spi_master *master = dev_id;
bf5c2e27 AL	94	struct spi_clps711x_data *hw = spi_master_get_devdata(master);
c7a26f12	95	u8 data;
161b96c3 AS	96
161b96c3 AS	97	/* Handle RX */
3dc92594	98	data = readb(hw->syncio);
161b96c3	99	if (hw->rx_buf)
c7a26f12	100	*hw->rx_buf++ = data;
161b96c3 AS	101
161b96c3 AS	102	/* Handle TX */
c7a26f12 AS	103	if (--hw->len > 0) {
c7a26f12 AS	104	data = hw->tx_buf ? *hw->tx_buf++ : 0;
3dc92594 AS	105	writel(data \| SYNCIO_FRMLEN(hw->bpw) \| SYNCIO_TXFRMEN,
3dc92594 AS	106	hw->syncio);
161b96c3	107	} else
bf5c2e27	108	spi_finalize_current_transfer(master);
161b96c3 AS	109
	110	return IRQ_HANDLED;
	111	}
	112
fd4a319b	113	static int spi_clps711x_probe(struct platform_device *pdev)
161b96c3	114	{
161b96c3	115	struct spi_clps711x_data *hw;
3dc92594 AS	116	struct spi_master *master;
3dc92594 AS	117	struct resource *res;
6acaadc8	118	int irq, ret;
161b96c3	119
3dc92594 AS	120	irq = platform_get_irq(pdev, 0);
	121	if (irq < 0)
	122	return irq;
	123
3e9ea4b4 AS	124	master = spi_alloc_master(&pdev->dev, sizeof(*hw));
3e9ea4b4 AS	125	if (!master)
161b96c3	126	return -ENOMEM;
3e9ea4b4	127
6acaadc8	128	master->bus_num = -1;
161b96c3	129	master->mode_bits = SPI_CPHA \| SPI_CS_HIGH;
8dda9d9a	130	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 8);
6acaadc8	131	master->dev.of_node = pdev->dev.of_node;
161b96c3	132	master->setup = spi_clps711x_setup;
bf5c2e27 AL	133	master->prepare_message = spi_clps711x_prepare_message;
bf5c2e27 AL	134	master->transfer_one = spi_clps711x_transfer_one;
161b96c3 AS	135
	136	hw = spi_master_get_devdata(master);
	137
a5b4b234	138	hw->spi_clk = devm_clk_get(&pdev->dev, NULL);
161b96c3	139	if (IS_ERR(hw->spi_clk)) {
161b96c3 AS	140	ret = PTR_ERR(hw->spi_clk);
	141	goto err_out;
	142	}
161b96c3	143
6acaadc8 AS	144	hw->syscon =
6acaadc8 AS	145	syscon_regmap_lookup_by_compatible("cirrus,ep7209-syscon3");
3dc92594 AS	146	if (IS_ERR(hw->syscon)) {
	147	ret = PTR_ERR(hw->syscon);
	148	goto err_out;
	149	}
	150
3dc92594 AS	151	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	152	hw->syncio = devm_ioremap_resource(&pdev->dev, res);
	153	if (IS_ERR(hw->syncio)) {
	154	ret = PTR_ERR(hw->syncio);
	155	goto err_out;
	156	}
	157
161b96c3	158	/* Disable extended mode due hardware problems */
3dc92594	159	regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCON, 0);
161b96c3 AS	160
161b96c3 AS	161	/* Clear possible pending interrupt */
3dc92594	162	readl(hw->syncio);
161b96c3	163
3dc92594	164	ret = devm_request_irq(&pdev->dev, irq, spi_clps711x_isr, 0,
bf5c2e27	165	dev_name(&pdev->dev), master);
3dc92594	166	if (ret)
c7083790	167	goto err_out;
161b96c3	168
c493fc4b	169	ret = devm_spi_register_master(&pdev->dev, master);
6acaadc8	170	if (!ret)
161b96c3	171	return 0;
161b96c3	172
161b96c3	173	err_out:
161b96c3	174	spi_master_put(master);
161b96c3 AS	175
	176	return ret;
	177	}
	178
6acaadc8 AS	179	static const struct of_device_id clps711x_spi_dt_ids[] = {
	180	{ .compatible = "cirrus,ep7209-spi", },
	181	{ }
	182	};
	183	MODULE_DEVICE_TABLE(of, clps711x_spi_dt_ids);
	184
161b96c3 AS	185	static struct platform_driver clps711x_spi_driver = {
	186	.driver = {
	187	.name = DRIVER_NAME,
6acaadc8	188	.of_match_table = clps711x_spi_dt_ids,
161b96c3 AS	189	},
161b96c3 AS	190	.probe = spi_clps711x_probe,
161b96c3 AS	191	};
	192	module_platform_driver(clps711x_spi_driver);
	193
	194	MODULE_LICENSE("GPL");
	195	MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
	196	MODULE_DESCRIPTION("CLPS711X SPI bus driver");
350a9b33	197	MODULE_ALIAS("platform:" DRIVER_NAME);