i2c/s5c73m3/s5c73m3-spi.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Samsung LSI S5C73M3 8M pixel camera driver
0004  *
0005  * Copyright (C) 2012, Samsung Electronics, Co., Ltd.
0006  * Sylwester Nawrocki <s.nawrocki@samsung.com>
0007  * Andrzej Hajda <a.hajda@samsung.com>
0008  */
0009
0010 #include <linux/sizes.h>
0011 #include <linux/delay.h>
0012 #include <linux/init.h>
0013 #include <linux/media.h>
0014 #include <linux/module.h>
0015 #include <linux/slab.h>
0016 #include <linux/spi/spi.h>
0017
0018 #include "s5c73m3.h"
0019
0020 #define S5C73M3_SPI_DRV_NAME "S5C73M3-SPI"
0021
0022 static const struct of_device_id s5c73m3_spi_ids[] = {
0023     { .compatible = "samsung,s5c73m3" },
0024     { }
0025 };
0026 MODULE_DEVICE_TABLE(of, s5c73m3_spi_ids);
0027
0028 enum spi_direction {
0029     SPI_DIR_RX,
0030     SPI_DIR_TX
0031 };
0032
0033 static int spi_xmit(struct spi_device *spi_dev, void *addr, const int len,
0034                             enum spi_direction dir)
0035 {
0036     struct spi_message msg;
0037     int r;
0038     struct spi_transfer xfer = {
0039         .len    = len,
0040     };
0041
0042     if (dir == SPI_DIR_TX)
0043         xfer.tx_buf = addr;
0044     else
0045         xfer.rx_buf = addr;
0046
0047     if (spi_dev == NULL) {
0048         pr_err("SPI device is uninitialized\n");
0049         return -ENODEV;
0050     }
0051
0052     spi_message_init(&msg);
0053     spi_message_add_tail(&xfer, &msg);
0054
0055     r = spi_sync(spi_dev, &msg);
0056     if (r < 0)
0057         dev_err(&spi_dev->dev, "%s spi_sync failed %d\n", __func__, r);
0058
0059     return r;
0060 }
0061
0062 int s5c73m3_spi_write(struct s5c73m3 *state, const void *addr,
0063               const unsigned int len, const unsigned int tx_size)
0064 {
0065     struct spi_device *spi_dev = state->spi_dev;
0066     u32 count = len / tx_size;
0067     u32 extra = len % tx_size;
0068     unsigned int i, j = 0;
0069     u8 padding[32];
0070     int r = 0;
0071
0072     memset(padding, 0, sizeof(padding));
0073
0074     for (i = 0; i < count; i++) {
0075         r = spi_xmit(spi_dev, (void *)addr + j, tx_size, SPI_DIR_TX);
0076         if (r < 0)
0077             return r;
0078         j += tx_size;
0079     }
0080
0081     if (extra > 0) {
0082         r = spi_xmit(spi_dev, (void *)addr + j, extra, SPI_DIR_TX);
0083         if (r < 0)
0084             return r;
0085     }
0086
0087     return spi_xmit(spi_dev, padding, sizeof(padding), SPI_DIR_TX);
0088 }
0089
0090 int s5c73m3_spi_read(struct s5c73m3 *state, void *addr,
0091              const unsigned int len, const unsigned int tx_size)
0092 {
0093     struct spi_device *spi_dev = state->spi_dev;
0094     u32 count = len / tx_size;
0095     u32 extra = len % tx_size;
0096     unsigned int i, j = 0;
0097     int r = 0;
0098
0099     for (i = 0; i < count; i++) {
0100         r = spi_xmit(spi_dev, addr + j, tx_size, SPI_DIR_RX);
0101         if (r < 0)
0102             return r;
0103         j += tx_size;
0104     }
0105
0106     if (extra > 0)
0107         return spi_xmit(spi_dev, addr + j, extra, SPI_DIR_RX);
0108
0109     return 0;
0110 }
0111
0112 static int s5c73m3_spi_probe(struct spi_device *spi)
0113 {
0114     int r;
0115     struct s5c73m3 *state = container_of(spi->dev.driver, struct s5c73m3,
0116                          spidrv.driver);
0117     spi->bits_per_word = 32;
0118
0119     r = spi_setup(spi);
0120     if (r < 0) {
0121         dev_err(&spi->dev, "spi_setup() failed\n");
0122         return r;
0123     }
0124
0125     mutex_lock(&state->lock);
0126     state->spi_dev = spi;
0127     mutex_unlock(&state->lock);
0128
0129     v4l2_info(&state->sensor_sd, "S5C73M3 SPI probed successfully\n");
0130     return 0;
0131 }
0132
0133 int s5c73m3_register_spi_driver(struct s5c73m3 *state)
0134 {
0135     struct spi_driver *spidrv = &state->spidrv;
0136
0137     spidrv->probe = s5c73m3_spi_probe;
0138     spidrv->driver.name = S5C73M3_SPI_DRV_NAME;
0139     spidrv->driver.of_match_table = s5c73m3_spi_ids;
0140
0141     return spi_register_driver(spidrv);
0142 }
0143
0144 void s5c73m3_unregister_spi_driver(struct s5c73m3 *state)
0145 {
0146     spi_unregister_driver(&state->spidrv);
0147 }