1 // SPDX-License-Identifier: GPL-2.0 2 /* DSA driver for: 3 * Vitesse VSC7385 SparX-G5 5+1-port Integrated Gigabit Ethernet Switch 4 * Vitesse VSC7388 SparX-G8 8-port Integrated Gigabit Ethernet Switch 5 * Vitesse VSC7395 SparX-G5e 5+1-port Integrated Gigabit Ethernet Switch 6 * Vitesse VSC7398 SparX-G8e 8-port Integrated Gigabit Ethernet Switch 7 * 8 * This driver takes control of the switch chip over SPI and 9 * configures it to route packages around when connected to a CPU port. 10 * 11 * Copyright (C) 2018 Linus Wallej <linus.walleij@linaro.org> 12 * Includes portions of code from the firmware uploader by: 13 * Copyright (C) 2009 Gabor Juhos <juhosg@openwrt.org> 14 */ 15 #include <linux/kernel.h> 16 #include <linux/module.h> 17 #include <linux/of.h> 18 #include <linux/spi/spi.h> 19 20 #include "vitesse-vsc73xx.h" 21 22 #define VSC73XX_CMD_SPI_MODE_READ 0 23 #define VSC73XX_CMD_SPI_MODE_WRITE 1 24 #define VSC73XX_CMD_SPI_MODE_SHIFT 4 25 #define VSC73XX_CMD_SPI_BLOCK_SHIFT 5 26 #define VSC73XX_CMD_SPI_BLOCK_MASK 0x7 27 #define VSC73XX_CMD_SPI_SUBBLOCK_MASK 0xf 28 29 /* 30 * struct vsc73xx_spi - VSC73xx SPI state container 31 */ 32 struct vsc73xx_spi { 33 struct spi_device *spi; 34 struct mutex lock; /* Protects SPI traffic */ 35 struct vsc73xx vsc; 36 }; 37 38 static const struct vsc73xx_ops vsc73xx_spi_ops; 39 40 static u8 vsc73xx_make_addr(u8 mode, u8 block, u8 subblock) 41 { 42 u8 ret; 43 44 ret = 45 (block & VSC73XX_CMD_SPI_BLOCK_MASK) << VSC73XX_CMD_SPI_BLOCK_SHIFT; 46 ret |= (mode & 1) << VSC73XX_CMD_SPI_MODE_SHIFT; 47 ret |= subblock & VSC73XX_CMD_SPI_SUBBLOCK_MASK; 48 49 return ret; 50 } 51 52 static int vsc73xx_spi_read(struct vsc73xx *vsc, u8 block, u8 subblock, u8 reg, 53 u32 *val) 54 { 55 struct vsc73xx_spi *vsc_spi = vsc->priv; 56 struct spi_transfer t[2]; 57 struct spi_message m; 58 u8 cmd[4]; 59 u8 buf[4]; 60 int ret; 61 62 if (!vsc73xx_is_addr_valid(block, subblock)) 63 return -EINVAL; 64 65 spi_message_init(&m); 66 67 memset(&t, 0, sizeof(t)); 68 69 t[0].tx_buf = cmd; 70 t[0].len = sizeof(cmd); 71 spi_message_add_tail(&t[0], &m); 72 73 t[1].rx_buf = buf; 74 t[1].len = sizeof(buf); 75 spi_message_add_tail(&t[1], &m); 76 77 cmd[0] = vsc73xx_make_addr(VSC73XX_CMD_SPI_MODE_READ, block, subblock); 78 cmd[1] = reg; 79 cmd[2] = 0; 80 cmd[3] = 0; 81 82 mutex_lock(&vsc_spi->lock); 83 ret = spi_sync(vsc_spi->spi, &m); 84 mutex_unlock(&vsc_spi->lock); 85 86 if (ret) 87 return ret; 88 89 *val = (buf[0] << 24) | (buf[1] << 16) | (buf[2] << 8) | buf[3]; 90 91 return 0; 92 } 93 94 static int vsc73xx_spi_write(struct vsc73xx *vsc, u8 block, u8 subblock, u8 reg, 95 u32 val) 96 { 97 struct vsc73xx_spi *vsc_spi = vsc->priv; 98 struct spi_transfer t[2]; 99 struct spi_message m; 100 u8 cmd[2]; 101 u8 buf[4]; 102 int ret; 103 104 if (!vsc73xx_is_addr_valid(block, subblock)) 105 return -EINVAL; 106 107 spi_message_init(&m); 108 109 memset(&t, 0, sizeof(t)); 110 111 t[0].tx_buf = cmd; 112 t[0].len = sizeof(cmd); 113 spi_message_add_tail(&t[0], &m); 114 115 t[1].tx_buf = buf; 116 t[1].len = sizeof(buf); 117 spi_message_add_tail(&t[1], &m); 118 119 cmd[0] = vsc73xx_make_addr(VSC73XX_CMD_SPI_MODE_WRITE, block, subblock); 120 cmd[1] = reg; 121 122 buf[0] = (val >> 24) & 0xff; 123 buf[1] = (val >> 16) & 0xff; 124 buf[2] = (val >> 8) & 0xff; 125 buf[3] = val & 0xff; 126 127 mutex_lock(&vsc_spi->lock); 128 ret = spi_sync(vsc_spi->spi, &m); 129 mutex_unlock(&vsc_spi->lock); 130 131 return ret; 132 } 133 134 static int vsc73xx_spi_probe(struct spi_device *spi) 135 { 136 struct device *dev = &spi->dev; 137 struct vsc73xx_spi *vsc_spi; 138 int ret; 139 140 vsc_spi = devm_kzalloc(dev, sizeof(*vsc_spi), GFP_KERNEL); 141 if (!vsc_spi) 142 return -ENOMEM; 143 144 spi_set_drvdata(spi, vsc_spi); 145 vsc_spi->spi = spi_dev_get(spi); 146 vsc_spi->vsc.dev = dev; 147 vsc_spi->vsc.priv = vsc_spi; 148 vsc_spi->vsc.ops = &vsc73xx_spi_ops; 149 mutex_init(&vsc_spi->lock); 150 151 spi->mode = SPI_MODE_0; 152 spi->bits_per_word = 8; 153 ret = spi_setup(spi); 154 if (ret < 0) { 155 dev_err(dev, "spi setup failed.\n"); 156 return ret; 157 } 158 159 return vsc73xx_probe(&vsc_spi->vsc); 160 } 161 162 static int vsc73xx_spi_remove(struct spi_device *spi) 163 { 164 struct vsc73xx_spi *vsc_spi = spi_get_drvdata(spi); 165 166 if (!vsc_spi) 167 return 0; 168 169 vsc73xx_remove(&vsc_spi->vsc); 170 171 spi_set_drvdata(spi, NULL); 172 173 return 0; 174 } 175 176 static void vsc73xx_spi_shutdown(struct spi_device *spi) 177 { 178 struct vsc73xx_spi *vsc_spi = spi_get_drvdata(spi); 179 180 if (!vsc_spi) 181 return; 182 183 vsc73xx_shutdown(&vsc_spi->vsc); 184 185 spi_set_drvdata(spi, NULL); 186 } 187 188 static const struct vsc73xx_ops vsc73xx_spi_ops = { 189 .read = vsc73xx_spi_read, 190 .write = vsc73xx_spi_write, 191 }; 192 193 static const struct of_device_id vsc73xx_of_match[] = { 194 { 195 .compatible = "vitesse,vsc7385", 196 }, 197 { 198 .compatible = "vitesse,vsc7388", 199 }, 200 { 201 .compatible = "vitesse,vsc7395", 202 }, 203 { 204 .compatible = "vitesse,vsc7398", 205 }, 206 { }, 207 }; 208 MODULE_DEVICE_TABLE(of, vsc73xx_of_match); 209 210 static struct spi_driver vsc73xx_spi_driver = { 211 .probe = vsc73xx_spi_probe, 212 .remove = vsc73xx_spi_remove, 213 .shutdown = vsc73xx_spi_shutdown, 214 .driver = { 215 .name = "vsc73xx-spi", 216 .of_match_table = vsc73xx_of_match, 217 }, 218 }; 219 module_spi_driver(vsc73xx_spi_driver); 220 221 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); 222 MODULE_DESCRIPTION("Vitesse VSC7385/7388/7395/7398 SPI driver"); 223 MODULE_LICENSE("GPL v2"); 224