1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * LPC32xx I2C interface driver 4 * 5 * (C) Copyright 2014-2015 DENX Software Engineering GmbH 6 * Written-by: Albert ARIBAUD - 3ADEV <albert.aribaud (at) 3adev.fr> 7 */ 8 9 #include <common.h> 10 #include <asm/io.h> 11 #include <i2c.h> 12 #include <linux/errno.h> 13 #include <asm/arch/clk.h> 14 #include <asm/arch/i2c.h> 15 #include <dm.h> 16 #include <mapmem.h> 17 18 /* 19 * Provide default speed and slave if target did not 20 */ 21 22 #if !defined(CONFIG_SYS_I2C_LPC32XX_SPEED) 23 #define CONFIG_SYS_I2C_LPC32XX_SPEED 350000 24 #endif 25 26 #if !defined(CONFIG_SYS_I2C_LPC32XX_SLAVE) 27 #define CONFIG_SYS_I2C_LPC32XX_SLAVE 0 28 #endif 29 30 /* TX register fields */ 31 #define LPC32XX_I2C_TX_START 0x00000100 32 #define LPC32XX_I2C_TX_STOP 0x00000200 33 34 /* Control register values */ 35 #define LPC32XX_I2C_SOFT_RESET 0x00000100 36 37 /* Status register values */ 38 #define LPC32XX_I2C_STAT_TFF 0x00000400 39 #define LPC32XX_I2C_STAT_RFE 0x00000200 40 #define LPC32XX_I2C_STAT_DRMI 0x00000008 41 #define LPC32XX_I2C_STAT_NAI 0x00000004 42 #define LPC32XX_I2C_STAT_TDI 0x00000001 43 44 #ifndef CONFIG_DM_I2C 45 static struct lpc32xx_i2c_base *lpc32xx_i2c[] = { 46 (struct lpc32xx_i2c_base *)I2C1_BASE, 47 (struct lpc32xx_i2c_base *)I2C2_BASE, 48 (struct lpc32xx_i2c_base *)(USB_BASE + 0x300) 49 }; 50 #endif 51 52 /* Set I2C bus speed */ 53 static unsigned int __i2c_set_bus_speed(struct lpc32xx_i2c_base *base, 54 unsigned int speed, unsigned int chip) 55 { 56 int half_period; 57 58 if (speed == 0) 59 return -EINVAL; 60 61 /* OTG I2C clock source and CLK registers are different */ 62 if (chip == 2) { 63 half_period = (get_periph_clk_rate() / speed) / 2; 64 if (half_period > 0xFF) 65 return -EINVAL; 66 } else { 67 half_period = (get_hclk_clk_rate() / speed) / 2; 68 if (half_period > 0x3FF) 69 return -EINVAL; 70 } 71 72 writel(half_period, &base->clk_hi); 73 writel(half_period, &base->clk_lo); 74 return 0; 75 } 76 77 /* I2C init called by cmd_i2c when doing 'i2c reset'. */ 78 static void __i2c_init(struct lpc32xx_i2c_base *base, 79 int requested_speed, int slaveadd, unsigned int chip) 80 { 81 /* soft reset (auto-clears) */ 82 writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl); 83 /* set HI and LO periods for half of the default speed */ 84 __i2c_set_bus_speed(base, requested_speed, chip); 85 } 86 87 /* I2C probe called by cmd_i2c when doing 'i2c probe'. */ 88 static int __i2c_probe_chip(struct lpc32xx_i2c_base *base, u8 dev) 89 { 90 int stat; 91 92 /* Soft-reset the controller */ 93 writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl); 94 while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET) 95 ; 96 /* Addre slave for write with start before and stop after */ 97 writel((dev<<1) | LPC32XX_I2C_TX_START | LPC32XX_I2C_TX_STOP, 98 &base->tx); 99 /* wait for end of transation */ 100 while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI)) 101 ; 102 /* was there no acknowledge? */ 103 return (stat & LPC32XX_I2C_STAT_NAI) ? -1 : 0; 104 } 105 106 /* 107 * I2C read called by cmd_i2c when doing 'i2c read' and by cmd_eeprom.c 108 * Begin write, send address byte(s), begin read, receive data bytes, end. 109 */ 110 static int __i2c_read(struct lpc32xx_i2c_base *base, u8 dev, uint addr, 111 int alen, u8 *data, int length) 112 { 113 int stat, wlen; 114 115 /* Soft-reset the controller */ 116 writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl); 117 while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET) 118 ; 119 /* do we need to write an address at all? */ 120 if (alen) { 121 /* Address slave in write mode */ 122 writel((dev<<1) | LPC32XX_I2C_TX_START, &base->tx); 123 /* write address bytes */ 124 while (alen--) { 125 /* compute address byte + stop for the last one */ 126 int a = (addr >> (8 * alen)) & 0xff; 127 if (!alen) 128 a |= LPC32XX_I2C_TX_STOP; 129 /* Send address byte */ 130 writel(a, &base->tx); 131 } 132 /* wait for end of transation */ 133 while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI)) 134 ; 135 /* clear end-of-transaction flag */ 136 writel(1, &base->stat); 137 } 138 /* do we have to read data at all? */ 139 if (length) { 140 /* Address slave in read mode */ 141 writel(1 | (dev<<1) | LPC32XX_I2C_TX_START, &base->tx); 142 wlen = length; 143 /* get data */ 144 while (length | wlen) { 145 /* read status for TFF and RFE */ 146 stat = readl(&base->stat); 147 /* must we, can we write a trigger byte? */ 148 if ((wlen > 0) 149 & (!(stat & LPC32XX_I2C_STAT_TFF))) { 150 wlen--; 151 /* write trigger byte + stop if last */ 152 writel(wlen ? 0 : 153 LPC32XX_I2C_TX_STOP, &base->tx); 154 } 155 /* must we, can we read a data byte? */ 156 if ((length > 0) 157 & (!(stat & LPC32XX_I2C_STAT_RFE))) { 158 length--; 159 /* read byte */ 160 *(data++) = readl(&base->rx); 161 } 162 } 163 /* wait for end of transation */ 164 while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI)) 165 ; 166 /* clear end-of-transaction flag */ 167 writel(1, &base->stat); 168 } 169 /* success */ 170 return 0; 171 } 172 173 /* 174 * I2C write called by cmd_i2c when doing 'i2c write' and by cmd_eeprom.c 175 * Begin write, send address byte(s), send data bytes, end. 176 */ 177 static int __i2c_write(struct lpc32xx_i2c_base *base, u8 dev, uint addr, 178 int alen, u8 *data, int length) 179 { 180 int stat; 181 182 /* Soft-reset the controller */ 183 writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl); 184 while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET) 185 ; 186 /* do we need to write anything at all? */ 187 if (alen | length) 188 /* Address slave in write mode */ 189 writel((dev<<1) | LPC32XX_I2C_TX_START, &base->tx); 190 else 191 return 0; 192 /* write address bytes */ 193 while (alen) { 194 /* wait for transmit fifo not full */ 195 stat = readl(&base->stat); 196 if (!(stat & LPC32XX_I2C_STAT_TFF)) { 197 alen--; 198 int a = (addr >> (8 * alen)) & 0xff; 199 if (!(alen | length)) 200 a |= LPC32XX_I2C_TX_STOP; 201 /* Send address byte */ 202 writel(a, &base->tx); 203 } 204 } 205 while (length) { 206 /* wait for transmit fifo not full */ 207 stat = readl(&base->stat); 208 if (!(stat & LPC32XX_I2C_STAT_TFF)) { 209 /* compute data byte, add stop if length==0 */ 210 length--; 211 int d = *(data++); 212 if (!length) 213 d |= LPC32XX_I2C_TX_STOP; 214 /* Send data byte */ 215 writel(d, &base->tx); 216 } 217 } 218 /* wait for end of transation */ 219 while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI)) 220 ; 221 /* clear end-of-transaction flag */ 222 writel(1, &base->stat); 223 return 0; 224 } 225 226 #ifndef CONFIG_DM_I2C 227 static void lpc32xx_i2c_init(struct i2c_adapter *adap, 228 int requested_speed, int slaveadd) 229 { 230 __i2c_init(lpc32xx_i2c[adap->hwadapnr], requested_speed, slaveadd, 231 adap->hwadapnr); 232 } 233 234 static int lpc32xx_i2c_probe_chip(struct i2c_adapter *adap, u8 dev) 235 { 236 return __i2c_probe_chip(lpc32xx_i2c[adap->hwadapnr], dev); 237 } 238 239 static int lpc32xx_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr, 240 int alen, u8 *data, int length) 241 { 242 return __i2c_read(lpc32xx_i2c[adap->hwadapnr], dev, addr, 243 alen, data, length); 244 } 245 246 static int lpc32xx_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr, 247 int alen, u8 *data, int length) 248 { 249 return __i2c_write(lpc32xx_i2c[adap->hwadapnr], dev, addr, 250 alen, data, length); 251 } 252 253 static unsigned int lpc32xx_i2c_set_bus_speed(struct i2c_adapter *adap, 254 unsigned int speed) 255 { 256 return __i2c_set_bus_speed(lpc32xx_i2c[adap->hwadapnr], speed, 257 adap->hwadapnr); 258 } 259 260 U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_0, lpc32xx_i2c_init, lpc32xx_i2c_probe_chip, 261 lpc32xx_i2c_read, lpc32xx_i2c_write, 262 lpc32xx_i2c_set_bus_speed, 263 CONFIG_SYS_I2C_LPC32XX_SPEED, 264 CONFIG_SYS_I2C_LPC32XX_SLAVE, 265 0) 266 267 U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_1, lpc32xx_i2c_init, lpc32xx_i2c_probe_chip, 268 lpc32xx_i2c_read, lpc32xx_i2c_write, 269 lpc32xx_i2c_set_bus_speed, 270 CONFIG_SYS_I2C_LPC32XX_SPEED, 271 CONFIG_SYS_I2C_LPC32XX_SLAVE, 272 1) 273 274 U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_2, lpc32xx_i2c_init, NULL, 275 lpc32xx_i2c_read, lpc32xx_i2c_write, 276 lpc32xx_i2c_set_bus_speed, 277 100000, 278 0, 279 2) 280 #else /* CONFIG_DM_I2C */ 281 static int lpc32xx_i2c_probe(struct udevice *bus) 282 { 283 struct lpc32xx_i2c_dev *dev = dev_get_platdata(bus); 284 bus->seq = dev->index; 285 286 __i2c_init(dev->base, dev->speed, 0, dev->index); 287 return 0; 288 } 289 290 static int lpc32xx_i2c_probe_chip(struct udevice *bus, u32 chip_addr, 291 u32 chip_flags) 292 { 293 struct lpc32xx_i2c_dev *dev = dev_get_platdata(bus); 294 return __i2c_probe_chip(dev->base, chip_addr); 295 } 296 297 static int lpc32xx_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, 298 int nmsgs) 299 { 300 struct lpc32xx_i2c_dev *dev = dev_get_platdata(bus); 301 struct i2c_msg *dmsg, *omsg, dummy; 302 uint i = 0, address = 0; 303 304 memset(&dummy, 0, sizeof(struct i2c_msg)); 305 306 /* We expect either two messages (one with an offset and one with the 307 * actual data) or one message (just data) 308 */ 309 if (nmsgs > 2 || nmsgs == 0) { 310 debug("%s: Only one or two messages are supported.", __func__); 311 return -1; 312 } 313 314 omsg = nmsgs == 1 ? &dummy : msg; 315 dmsg = nmsgs == 1 ? msg : msg + 1; 316 317 /* the address is expected to be a uint, not a array. */ 318 address = omsg->buf[0]; 319 for (i = 1; i < omsg->len; i++) 320 address = (address << 8) + omsg->buf[i]; 321 322 if (dmsg->flags & I2C_M_RD) 323 return __i2c_read(dev->base, dmsg->addr, address, 324 omsg->len, dmsg->buf, dmsg->len); 325 else 326 return __i2c_write(dev->base, dmsg->addr, address, 327 omsg->len, dmsg->buf, dmsg->len); 328 } 329 330 static int lpc32xx_i2c_set_bus_speed(struct udevice *bus, unsigned int speed) 331 { 332 struct lpc32xx_i2c_dev *dev = dev_get_platdata(bus); 333 return __i2c_set_bus_speed(dev->base, speed, dev->index); 334 } 335 336 static int lpc32xx_i2c_reset(struct udevice *bus) 337 { 338 struct lpc32xx_i2c_dev *dev = dev_get_platdata(bus); 339 340 __i2c_init(dev->base, dev->speed, 0, dev->index); 341 return 0; 342 } 343 344 static const struct dm_i2c_ops lpc32xx_i2c_ops = { 345 .xfer = lpc32xx_i2c_xfer, 346 .probe_chip = lpc32xx_i2c_probe_chip, 347 .deblock = lpc32xx_i2c_reset, 348 .set_bus_speed = lpc32xx_i2c_set_bus_speed, 349 }; 350 351 U_BOOT_DRIVER(i2c_lpc32xx) = { 352 .id = UCLASS_I2C, 353 .name = "i2c_lpc32xx", 354 .probe = lpc32xx_i2c_probe, 355 .ops = &lpc32xx_i2c_ops, 356 }; 357 #endif /* CONFIG_DM_I2C */ 358
