s5c73m3-spi.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Samsung LSI S5C73M3 8M pixel camera driver
  4 *
  5 * Copyright (C) 2012, Samsung Electronics, Co., Ltd.
  6 * Sylwester Nawrocki <s.nawrocki@samsung.com>
  7 * Andrzej Hajda <a.hajda@samsung.com>
  8 */
  9
 10#include <linux/sizes.h>
 11#include <linux/delay.h>
 12#include <linux/init.h>
 13#include <linux/media.h>
 14#include <linux/module.h>
 15#include <linux/slab.h>
 16#include <linux/spi/spi.h>
 17
 18#include "s5c73m3.h"
 19
 20#define S5C73M3_SPI_DRV_NAME "S5C73M3-SPI"
 21
 22static const struct of_device_id s5c73m3_spi_ids[] = {
 23	{ .compatible = "samsung,s5c73m3" },
 24	{ }
 25};
 26MODULE_DEVICE_TABLE(of, s5c73m3_spi_ids);
 27
 28enum spi_direction {
 29	SPI_DIR_RX,
 30	SPI_DIR_TX
 31};
 32
 33static int spi_xmit(struct spi_device *spi_dev, void *addr, const int len,
 34							enum spi_direction dir)
 35{
 36	struct spi_message msg;
 37	int r;
 38	struct spi_transfer xfer = {
 39		.len	= len,
 40	};
 41
 42	if (dir == SPI_DIR_TX)
 43		xfer.tx_buf = addr;
 44	else
 45		xfer.rx_buf = addr;
 46
 47	if (spi_dev == NULL) {
 48		pr_err("SPI device is uninitialized\n");
 49		return -ENODEV;
 50	}
 51
 52	spi_message_init(&msg);
 53	spi_message_add_tail(&xfer, &msg);
 54
 55	r = spi_sync(spi_dev, &msg);
 56	if (r < 0)
 57		dev_err(&spi_dev->dev, "%s spi_sync failed %d\n", __func__, r);
 58
 59	return r;
 60}
 61
 62int s5c73m3_spi_write(struct s5c73m3 *state, const void *addr,
 63		      const unsigned int len, const unsigned int tx_size)
 64{
 65	struct spi_device *spi_dev = state->spi_dev;
 66	u32 count = len / tx_size;
 67	u32 extra = len % tx_size;
 68	unsigned int i, j = 0;
 69	u8 padding[32];
 70	int r = 0;
 71
 72	memset(padding, 0, sizeof(padding));
 73
 74	for (i = 0; i < count; i++) {
 75		r = spi_xmit(spi_dev, (void *)addr + j, tx_size, SPI_DIR_TX);
 76		if (r < 0)
 77			return r;
 78		j += tx_size;
 79	}
 80
 81	if (extra > 0) {
 82		r = spi_xmit(spi_dev, (void *)addr + j, extra, SPI_DIR_TX);
 83		if (r < 0)
 84			return r;
 85	}
 86
 87	return spi_xmit(spi_dev, padding, sizeof(padding), SPI_DIR_TX);
 88}
 89
 90int s5c73m3_spi_read(struct s5c73m3 *state, void *addr,
 91		     const unsigned int len, const unsigned int tx_size)
 92{
 93	struct spi_device *spi_dev = state->spi_dev;
 94	u32 count = len / tx_size;
 95	u32 extra = len % tx_size;
 96	unsigned int i, j = 0;
 97	int r = 0;
 98
 99	for (i = 0; i < count; i++) {
100		r = spi_xmit(spi_dev, addr + j, tx_size, SPI_DIR_RX);
101		if (r < 0)
102			return r;
103		j += tx_size;
104	}
105
106	if (extra > 0)
107		return spi_xmit(spi_dev, addr + j, extra, SPI_DIR_RX);
108
109	return 0;
110}
111
112static int s5c73m3_spi_probe(struct spi_device *spi)
113{
114	int r;
115	struct s5c73m3 *state = container_of(spi->dev.driver, struct s5c73m3,
116					     spidrv.driver);
117	spi->bits_per_word = 32;
118
119	r = spi_setup(spi);
120	if (r < 0) {
121		dev_err(&spi->dev, "spi_setup() failed\n");
122		return r;
123	}
124
125	mutex_lock(&state->lock);
126	state->spi_dev = spi;
127	mutex_unlock(&state->lock);
128
129	v4l2_info(&state->sensor_sd, "S5C73M3 SPI probed successfully\n");
130	return 0;
131}
132
133int s5c73m3_register_spi_driver(struct s5c73m3 *state)
134{
135	struct spi_driver *spidrv = &state->spidrv;
136
137	spidrv->probe = s5c73m3_spi_probe;
138	spidrv->driver.name = S5C73M3_SPI_DRV_NAME;
139	spidrv->driver.of_match_table = s5c73m3_spi_ids;
140
141	return spi_register_driver(spidrv);
142}
143
144void s5c73m3_unregister_spi_driver(struct s5c73m3 *state)
145{
146	spi_unregister_driver(&state->spidrv);
147}