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 enum spi_direction { 31 SPI_DIR_RX, 32 SPI_DIR_TX 33 }; 34 35 static int spi_xmit(struct spi_device *spi_dev, void *addr, const int len, 36 enum spi_direction dir) 37 { 38 struct spi_message msg; 39 int r; 40 struct spi_transfer xfer = { 41 .len = len, 42 }; 43 44 if (dir == SPI_DIR_TX) 45 xfer.tx_buf = addr; 46 else 47 xfer.rx_buf = addr; 48 49 if (spi_dev == NULL) { 50 dev_err(&spi_dev->dev, "SPI device is uninitialized\n"); 51 return -ENODEV; 52 } 53 54 spi_message_init(&msg); 55 spi_message_add_tail(&xfer, &msg); 56 57 r = spi_sync(spi_dev, &msg); 58 if (r < 0) 59 dev_err(&spi_dev->dev, "%s spi_sync failed %d\n", __func__, r); 60 61 return r; 62 } 63 64 int s5c73m3_spi_write(struct s5c73m3 *state, const void *addr, 65 const unsigned int len, const unsigned int tx_size) 66 { 67 struct spi_device *spi_dev = state->spi_dev; 68 u32 count = len / tx_size; 69 u32 extra = len % tx_size; 70 unsigned int i, j = 0; 71 u8 padding[32]; 72 int r = 0; 73 74 memset(padding, 0, sizeof(padding)); 75 76 for (i = 0; i < count; i++) { 77 r = spi_xmit(spi_dev, (void *)addr + j, tx_size, SPI_DIR_TX); 78 if (r < 0) 79 return r; 80 j += tx_size; 81 } 82 83 if (extra > 0) { 84 r = spi_xmit(spi_dev, (void *)addr + j, extra, SPI_DIR_TX); 85 if (r < 0) 86 return r; 87 } 88 89 return spi_xmit(spi_dev, padding, sizeof(padding), SPI_DIR_TX); 90 } 91 92 int s5c73m3_spi_read(struct s5c73m3 *state, void *addr, 93 const unsigned int len, const unsigned int tx_size) 94 { 95 struct spi_device *spi_dev = state->spi_dev; 96 u32 count = len / tx_size; 97 u32 extra = len % tx_size; 98 unsigned int i, j = 0; 99 int r = 0; 100 101 for (i = 0; i < count; i++) { 102 r = spi_xmit(spi_dev, addr + j, tx_size, SPI_DIR_RX); 103 if (r < 0) 104 return r; 105 j += tx_size; 106 } 107 108 if (extra > 0) 109 return spi_xmit(spi_dev, addr + j, extra, SPI_DIR_RX); 110 111 return 0; 112 } 113 114 static int s5c73m3_spi_probe(struct spi_device *spi) 115 { 116 int r; 117 struct s5c73m3 *state = container_of(spi->dev.driver, struct s5c73m3, 118 spidrv.driver); 119 spi->bits_per_word = 32; 120 121 r = spi_setup(spi); 122 if (r < 0) { 123 dev_err(&spi->dev, "spi_setup() failed\n"); 124 return r; 125 } 126 127 mutex_lock(&state->lock); 128 state->spi_dev = spi; 129 mutex_unlock(&state->lock); 130 131 v4l2_info(&state->sensor_sd, "S5C73M3 SPI probed successfully\n"); 132 return 0; 133 } 134 135 static int s5c73m3_spi_remove(struct spi_device *spi) 136 { 137 return 0; 138 } 139 140 int s5c73m3_register_spi_driver(struct s5c73m3 *state) 141 { 142 struct spi_driver *spidrv = &state->spidrv; 143 144 spidrv->remove = s5c73m3_spi_remove; 145 spidrv->probe = s5c73m3_spi_probe; 146 spidrv->driver.name = S5C73M3_SPI_DRV_NAME; 147 spidrv->driver.bus = &spi_bus_type; 148 spidrv->driver.owner = THIS_MODULE; 149 150 return spi_register_driver(spidrv); 151 } 152 153 void s5c73m3_unregister_spi_driver(struct s5c73m3 *state) 154 { 155 spi_unregister_driver(&state->spidrv); 156 } 157