1 /* 2 * Samsung LSI S5C73M3 8M pixel camera driver 3 * 4 * Copyright (C) 2012, Samsung Electronics, Co., Ltd. 5 * Sylwester Nawrocki <s.nawrocki@samsung.com> 6 * Andrzej Hajda <a.hajda@samsung.com> 7 * 8 * This program is free software; you can redistribute it and/or 9 * modify it under the terms of the GNU General Public License 10 * version 2 as published by the Free Software Foundation. 11 * 12 * This program is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 */ 17 18 #include <linux/sizes.h> 19 #include <linux/delay.h> 20 #include <linux/init.h> 21 #include <linux/media.h> 22 #include <linux/module.h> 23 #include <linux/slab.h> 24 #include <linux/spi/spi.h> 25 26 #include "s5c73m3.h" 27 28 #define S5C73M3_SPI_DRV_NAME "S5C73M3-SPI" 29 30 static const struct of_device_id s5c73m3_spi_ids[] = { 31 { .compatible = "samsung,s5c73m3" }, 32 { } 33 }; 34 35 enum spi_direction { 36 SPI_DIR_RX, 37 SPI_DIR_TX 38 }; 39 40 static int spi_xmit(struct spi_device *spi_dev, void *addr, const int len, 41 enum spi_direction dir) 42 { 43 struct spi_message msg; 44 int r; 45 struct spi_transfer xfer = { 46 .len = len, 47 }; 48 49 if (dir == SPI_DIR_TX) 50 xfer.tx_buf = addr; 51 else 52 xfer.rx_buf = addr; 53 54 if (spi_dev == NULL) { 55 pr_err("SPI device is uninitialized\n"); 56 return -ENODEV; 57 } 58 59 spi_message_init(&msg); 60 spi_message_add_tail(&xfer, &msg); 61 62 r = spi_sync(spi_dev, &msg); 63 if (r < 0) 64 dev_err(&spi_dev->dev, "%s spi_sync failed %d\n", __func__, r); 65 66 return r; 67 } 68 69 int s5c73m3_spi_write(struct s5c73m3 *state, const void *addr, 70 const unsigned int len, const unsigned int tx_size) 71 { 72 struct spi_device *spi_dev = state->spi_dev; 73 u32 count = len / tx_size; 74 u32 extra = len % tx_size; 75 unsigned int i, j = 0; 76 u8 padding[32]; 77 int r = 0; 78 79 memset(padding, 0, sizeof(padding)); 80 81 for (i = 0; i < count; i++) { 82 r = spi_xmit(spi_dev, (void *)addr + j, tx_size, SPI_DIR_TX); 83 if (r < 0) 84 return r; 85 j += tx_size; 86 } 87 88 if (extra > 0) { 89 r = spi_xmit(spi_dev, (void *)addr + j, extra, SPI_DIR_TX); 90 if (r < 0) 91 return r; 92 } 93 94 return spi_xmit(spi_dev, padding, sizeof(padding), SPI_DIR_TX); 95 } 96 97 int s5c73m3_spi_read(struct s5c73m3 *state, void *addr, 98 const unsigned int len, const unsigned int tx_size) 99 { 100 struct spi_device *spi_dev = state->spi_dev; 101 u32 count = len / tx_size; 102 u32 extra = len % tx_size; 103 unsigned int i, j = 0; 104 int r = 0; 105 106 for (i = 0; i < count; i++) { 107 r = spi_xmit(spi_dev, addr + j, tx_size, SPI_DIR_RX); 108 if (r < 0) 109 return r; 110 j += tx_size; 111 } 112 113 if (extra > 0) 114 return spi_xmit(spi_dev, addr + j, extra, SPI_DIR_RX); 115 116 return 0; 117 } 118 119 static int s5c73m3_spi_probe(struct spi_device *spi) 120 { 121 int r; 122 struct s5c73m3 *state = container_of(spi->dev.driver, struct s5c73m3, 123 spidrv.driver); 124 spi->bits_per_word = 32; 125 126 r = spi_setup(spi); 127 if (r < 0) { 128 dev_err(&spi->dev, "spi_setup() failed\n"); 129 return r; 130 } 131 132 mutex_lock(&state->lock); 133 state->spi_dev = spi; 134 mutex_unlock(&state->lock); 135 136 v4l2_info(&state->sensor_sd, "S5C73M3 SPI probed successfully\n"); 137 return 0; 138 } 139 140 static int s5c73m3_spi_remove(struct spi_device *spi) 141 { 142 return 0; 143 } 144 145 int s5c73m3_register_spi_driver(struct s5c73m3 *state) 146 { 147 struct spi_driver *spidrv = &state->spidrv; 148 149 spidrv->remove = s5c73m3_spi_remove; 150 spidrv->probe = s5c73m3_spi_probe; 151 spidrv->driver.name = S5C73M3_SPI_DRV_NAME; 152 spidrv->driver.of_match_table = s5c73m3_spi_ids; 153 154 return spi_register_driver(spidrv); 155 } 156 157 void s5c73m3_unregister_spi_driver(struct s5c73m3 *state) 158 { 159 spi_unregister_driver(&state->spidrv); 160 } 161