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

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  CLPS711X SPI bus driver
 *
 *  Copyright (C) 2012-2016 Alexander Shiyan <shc_work@mail.ru>
 */

#include <linux/io.h>
#include <linux/clk.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/of.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_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 device_node *np = pdev->dev.of_node;
	struct spi_clps711x_data *hw;
	struct spi_master *master;
	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->use_gpio_descriptors = true;
	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->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_phandle(np, "syscon");
	if (IS_ERR(hw->syscon)) {
		ret = PTR_ERR(hw->syscon);
		goto err_out;
	}

	hw->syncio = devm_platform_ioremap_resource(pdev, 0);
	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
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
161b96c3 AS	2	/*
	3	* CLPS711X SPI bus driver
	4	*
6acaadc8	5	* Copyright (C) 2012-2016 Alexander Shiyan <shc_work@mail.ru>
161b96c3 AS	6	*/
	7
	8	#include <linux/io.h>
	9	#include <linux/clk.h>
054320b2	10	#include <linux/gpio/consumer.h>
161b96c3	11	#include <linux/module.h>
b0ceb621	12	#include <linux/of.h>
161b96c3 AS	13	#include <linux/interrupt.h>
161b96c3 AS	14	#include <linux/platform_device.h>
3dc92594 AS	15	#include <linux/regmap.h>
	16	#include <linux/mfd/syscon.h>
	17	#include <linux/mfd/syscon/clps711x.h>
161b96c3	18	#include <linux/spi/spi.h>
161b96c3	19
6acaadc8	20	#define DRIVER_NAME "clps711x-spi"
161b96c3	21
3dc92594 AS	22	#define SYNCIO_FRMLEN(x) ((x) << 8)
	23	#define SYNCIO_TXFRMEN (1 << 14)
	24
161b96c3	25	struct spi_clps711x_data {
3dc92594 AS	26	void __iomem *syncio;
3dc92594 AS	27	struct regmap *syscon;
161b96c3	28	struct clk *spi_clk;
161b96c3 AS	29
	30	u8 *tx_buf;
	31	u8 *rx_buf;
8dda9d9a	32	unsigned int bpw;
161b96c3	33	int len;
161b96c3 AS	34	};
161b96c3 AS	35
bf5c2e27 AL	36	static int spi_clps711x_prepare_message(struct spi_master *master,
bf5c2e27 AL	37	struct spi_message *msg)
161b96c3	38	{
3dc92594	39	struct spi_clps711x_data *hw = spi_master_get_devdata(master);
8dda9d9a	40	struct spi_device *spi = msg->spi;
161b96c3	41
3dc92594 AS	42	/* Setup mode for transfer */
	43	return regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCKNSEN,
	44	(spi->mode & SPI_CPHA) ?
	45	SYSCON3_ADCCKNSEN : 0);
bf5c2e27	46	}
161b96c3	47
bf5c2e27 AL	48	static int spi_clps711x_transfer_one(struct spi_master *master,
	49	struct spi_device *spi,
	50	struct spi_transfer *xfer)
	51	{
	52	struct spi_clps711x_data *hw = spi_master_get_devdata(master);
	53	u8 data;
161b96c3	54
a5b4b234	55	clk_set_rate(hw->spi_clk, xfer->speed_hz ? : spi->max_speed_hz);
161b96c3	56
bf5c2e27	57	hw->len = xfer->len;
bed890b4	58	hw->bpw = xfer->bits_per_word;
bf5c2e27 AL	59	hw->tx_buf = (u8 *)xfer->tx_buf;
bf5c2e27 AL	60	hw->rx_buf = (u8 *)xfer->rx_buf;
161b96c3	61
bf5c2e27 AL	62	/* Initiate transfer */
bf5c2e27 AL	63	data = hw->tx_buf ? *hw->tx_buf++ : 0;
3dc92594 AS	64	writel(data \| SYNCIO_FRMLEN(hw->bpw) \| SYNCIO_TXFRMEN, hw->syncio);
3dc92594 AS	65
bf5c2e27	66	return 1;
161b96c3 AS	67	}
	68
	69	static irqreturn_t spi_clps711x_isr(int irq, void *dev_id)
	70	{
bf5c2e27 AL	71	struct spi_master *master = dev_id;
bf5c2e27 AL	72	struct spi_clps711x_data *hw = spi_master_get_devdata(master);
c7a26f12	73	u8 data;
161b96c3 AS	74
161b96c3 AS	75	/* Handle RX */
3dc92594	76	data = readb(hw->syncio);
161b96c3	77	if (hw->rx_buf)
c7a26f12	78	*hw->rx_buf++ = data;
161b96c3 AS	79
161b96c3 AS	80	/* Handle TX */
c7a26f12 AS	81	if (--hw->len > 0) {
c7a26f12 AS	82	data = hw->tx_buf ? *hw->tx_buf++ : 0;
3dc92594 AS	83	writel(data \| SYNCIO_FRMLEN(hw->bpw) \| SYNCIO_TXFRMEN,
3dc92594 AS	84	hw->syncio);
161b96c3	85	} else
bf5c2e27	86	spi_finalize_current_transfer(master);
161b96c3 AS	87
	88	return IRQ_HANDLED;
	89	}
	90
fd4a319b	91	static int spi_clps711x_probe(struct platform_device *pdev)
161b96c3	92	{
b0ceb621	93	struct device_node *np = pdev->dev.of_node;
161b96c3	94	struct spi_clps711x_data *hw;
3dc92594	95	struct spi_master *master;
6acaadc8	96	int irq, ret;
161b96c3	97
3dc92594 AS	98	irq = platform_get_irq(pdev, 0);
	99	if (irq < 0)
	100	return irq;
	101
3e9ea4b4 AS	102	master = spi_alloc_master(&pdev->dev, sizeof(*hw));
3e9ea4b4 AS	103	if (!master)
161b96c3	104	return -ENOMEM;
3e9ea4b4	105
054320b2	106	master->use_gpio_descriptors = true;
6acaadc8	107	master->bus_num = -1;
161b96c3	108	master->mode_bits = SPI_CPHA \| SPI_CS_HIGH;
39062411	109	master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 8);
6acaadc8	110	master->dev.of_node = pdev->dev.of_node;
bf5c2e27 AL	111	master->prepare_message = spi_clps711x_prepare_message;
bf5c2e27 AL	112	master->transfer_one = spi_clps711x_transfer_one;
161b96c3 AS	113
	114	hw = spi_master_get_devdata(master);
	115
a5b4b234	116	hw->spi_clk = devm_clk_get(&pdev->dev, NULL);
161b96c3	117	if (IS_ERR(hw->spi_clk)) {
161b96c3 AS	118	ret = PTR_ERR(hw->spi_clk);
	119	goto err_out;
	120	}
161b96c3	121
b0ceb621	122	hw->syscon = syscon_regmap_lookup_by_phandle(np, "syscon");
3dc92594 AS	123	if (IS_ERR(hw->syscon)) {
	124	ret = PTR_ERR(hw->syscon);
	125	goto err_out;
	126	}
	127
ae43724d	128	hw->syncio = devm_platform_ioremap_resource(pdev, 0);
3dc92594 AS	129	if (IS_ERR(hw->syncio)) {
	130	ret = PTR_ERR(hw->syncio);
	131	goto err_out;
	132	}
	133
161b96c3	134	/* Disable extended mode due hardware problems */
3dc92594	135	regmap_update_bits(hw->syscon, SYSCON_OFFSET, SYSCON3_ADCCON, 0);
161b96c3 AS	136
161b96c3 AS	137	/* Clear possible pending interrupt */
3dc92594	138	readl(hw->syncio);
161b96c3	139
3dc92594	140	ret = devm_request_irq(&pdev->dev, irq, spi_clps711x_isr, 0,
bf5c2e27	141	dev_name(&pdev->dev), master);
3dc92594	142	if (ret)
c7083790	143	goto err_out;
161b96c3	144
c493fc4b	145	ret = devm_spi_register_master(&pdev->dev, master);
6acaadc8	146	if (!ret)
161b96c3	147	return 0;
161b96c3	148
161b96c3	149	err_out:
161b96c3	150	spi_master_put(master);
161b96c3 AS	151
	152	return ret;
	153	}
	154
6acaadc8 AS	155	static const struct of_device_id clps711x_spi_dt_ids[] = {
	156	{ .compatible = "cirrus,ep7209-spi", },
	157	{ }
	158	};
	159	MODULE_DEVICE_TABLE(of, clps711x_spi_dt_ids);
	160
161b96c3 AS	161	static struct platform_driver clps711x_spi_driver = {
	162	.driver = {
	163	.name = DRIVER_NAME,
6acaadc8	164	.of_match_table = clps711x_spi_dt_ids,
161b96c3 AS	165	},
161b96c3 AS	166	.probe = spi_clps711x_probe,
161b96c3 AS	167	};
	168	module_platform_driver(clps711x_spi_driver);
	169
	170	MODULE_LICENSE("GPL");
	171	MODULE_AUTHOR("Alexander Shiyan <shc_work@mail.ru>");
	172	MODULE_DESCRIPTION("CLPS711X SPI bus driver");
350a9b33	173	MODULE_ALIAS("platform:" DRIVER_NAME);