1 /* 2 * (C) Copyright 2015 Google, Inc 3 * 4 * (C) Copyright 2008-2014 Rockchip Electronics 5 * Peter, Software Engineering, <superpeter.cai@gmail.com>. 6 * 7 * SPDX-License-Identifier: GPL-2.0+ 8 */ 9 10 #include <common.h> 11 #include <clk.h> 12 #include <dm.h> 13 #include <errno.h> 14 #include <i2c.h> 15 #include <asm/io.h> 16 #include <asm/arch/clock.h> 17 #include <asm/arch/i2c.h> 18 #include <asm/arch/periph.h> 19 #include <dm/pinctrl.h> 20 #include <linux/sizes.h> 21 22 DECLARE_GLOBAL_DATA_PTR; 23 24 /* i2c timerout */ 25 #define I2C_TIMEOUT_MS 100 26 #define I2C_RETRY_COUNT 3 27 28 /* rk i2c fifo max transfer bytes */ 29 #define RK_I2C_FIFO_SIZE 32 30 31 struct rk_i2c { 32 struct clk clk; 33 struct i2c_regs *regs; 34 unsigned int speed; 35 }; 36 37 static inline void rk_i2c_get_div(int div, int *divh, int *divl) 38 { 39 *divl = div / 2; 40 if (div % 2 == 0) 41 *divh = div / 2; 42 else 43 *divh = DIV_ROUND_UP(div, 2); 44 } 45 46 /* 47 * SCL Divisor = 8 * (CLKDIVL+1 + CLKDIVH+1) 48 * SCL = PCLK / SCLK Divisor 49 * i2c_rate = PCLK 50 */ 51 static void rk_i2c_set_clk(struct rk_i2c *i2c, uint32_t scl_rate) 52 { 53 uint32_t i2c_rate; 54 int div, divl, divh; 55 56 /* First get i2c rate from pclk */ 57 i2c_rate = clk_get_rate(&i2c->clk); 58 59 div = DIV_ROUND_UP(i2c_rate, scl_rate * 8) - 2; 60 divh = 0; 61 divl = 0; 62 if (div >= 0) 63 rk_i2c_get_div(div, &divh, &divl); 64 writel(I2C_CLKDIV_VAL(divl, divh), &i2c->regs->clkdiv); 65 66 debug("rk_i2c_set_clk: i2c rate = %d, scl rate = %d\n", i2c_rate, 67 scl_rate); 68 debug("set i2c clk div = %d, divh = %d, divl = %d\n", div, divh, divl); 69 debug("set clk(I2C_CLKDIV: 0x%08x)\n", readl(&i2c->regs->clkdiv)); 70 } 71 72 static void rk_i2c_show_regs(struct i2c_regs *regs) 73 { 74 #ifdef DEBUG 75 uint i; 76 77 debug("i2c_con: 0x%08x\n", readl(®s->con)); 78 debug("i2c_clkdiv: 0x%08x\n", readl(®s->clkdiv)); 79 debug("i2c_mrxaddr: 0x%08x\n", readl(®s->mrxaddr)); 80 debug("i2c_mrxraddR: 0x%08x\n", readl(®s->mrxraddr)); 81 debug("i2c_mtxcnt: 0x%08x\n", readl(®s->mtxcnt)); 82 debug("i2c_mrxcnt: 0x%08x\n", readl(®s->mrxcnt)); 83 debug("i2c_ien: 0x%08x\n", readl(®s->ien)); 84 debug("i2c_ipd: 0x%08x\n", readl(®s->ipd)); 85 debug("i2c_fcnt: 0x%08x\n", readl(®s->fcnt)); 86 for (i = 0; i < 8; i++) 87 debug("i2c_txdata%d: 0x%08x\n", i, readl(®s->txdata[i])); 88 for (i = 0; i < 8; i++) 89 debug("i2c_rxdata%d: 0x%08x\n", i, readl(®s->rxdata[i])); 90 #endif 91 } 92 93 static int rk_i2c_send_start_bit(struct rk_i2c *i2c) 94 { 95 struct i2c_regs *regs = i2c->regs; 96 ulong start; 97 98 debug("I2c Send Start bit.\n"); 99 writel(I2C_IPD_ALL_CLEAN, ®s->ipd); 100 101 writel(I2C_CON_EN | I2C_CON_START, ®s->con); 102 writel(I2C_STARTIEN, ®s->ien); 103 104 start = get_timer(0); 105 while (1) { 106 if (readl(®s->ipd) & I2C_STARTIPD) { 107 writel(I2C_STARTIPD, ®s->ipd); 108 break; 109 } 110 if (get_timer(start) > I2C_TIMEOUT_MS) { 111 debug("I2C Send Start Bit Timeout\n"); 112 rk_i2c_show_regs(regs); 113 return -ETIMEDOUT; 114 } 115 udelay(1); 116 } 117 118 return 0; 119 } 120 121 static int rk_i2c_send_stop_bit(struct rk_i2c *i2c) 122 { 123 struct i2c_regs *regs = i2c->regs; 124 ulong start; 125 126 debug("I2c Send Stop bit.\n"); 127 writel(I2C_IPD_ALL_CLEAN, ®s->ipd); 128 129 writel(I2C_CON_EN | I2C_CON_STOP, ®s->con); 130 writel(I2C_CON_STOP, ®s->ien); 131 132 start = get_timer(0); 133 while (1) { 134 if (readl(®s->ipd) & I2C_STOPIPD) { 135 writel(I2C_STOPIPD, ®s->ipd); 136 break; 137 } 138 if (get_timer(start) > I2C_TIMEOUT_MS) { 139 debug("I2C Send Start Bit Timeout\n"); 140 rk_i2c_show_regs(regs); 141 return -ETIMEDOUT; 142 } 143 udelay(1); 144 } 145 146 return 0; 147 } 148 149 static inline void rk_i2c_disable(struct rk_i2c *i2c) 150 { 151 writel(0, &i2c->regs->con); 152 } 153 154 static int rk_i2c_read(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len, 155 uchar *buf, uint b_len) 156 { 157 struct i2c_regs *regs = i2c->regs; 158 uchar *pbuf = buf; 159 uint bytes_remain_len = b_len; 160 uint bytes_xferred = 0; 161 uint words_xferred = 0; 162 ulong start; 163 uint con = 0; 164 uint rxdata; 165 uint i, j; 166 int err; 167 bool snd_chunk = false; 168 169 debug("rk_i2c_read: chip = %d, reg = %d, r_len = %d, b_len = %d\n", 170 chip, reg, r_len, b_len); 171 172 err = rk_i2c_send_start_bit(i2c); 173 if (err) 174 return err; 175 176 writel(I2C_MRXADDR_SET(1, chip << 1 | 1), ®s->mrxaddr); 177 if (r_len == 0) { 178 writel(0, ®s->mrxraddr); 179 } else if (r_len < 4) { 180 writel(I2C_MRXRADDR_SET(r_len, reg), ®s->mrxraddr); 181 } else { 182 debug("I2C Read: addr len %d not supported\n", r_len); 183 return -EIO; 184 } 185 186 while (bytes_remain_len) { 187 if (bytes_remain_len > RK_I2C_FIFO_SIZE) { 188 con = I2C_CON_EN; 189 bytes_xferred = 32; 190 } else { 191 /* 192 * The hw can read up to 32 bytes at a time. If we need 193 * more than one chunk, send an ACK after the last byte. 194 */ 195 con = I2C_CON_EN | I2C_CON_LASTACK; 196 bytes_xferred = bytes_remain_len; 197 } 198 words_xferred = DIV_ROUND_UP(bytes_xferred, 4); 199 200 /* 201 * make sure we are in plain RX mode if we read a second chunk 202 */ 203 if (snd_chunk) 204 con |= I2C_CON_MOD(I2C_MODE_RX); 205 else 206 con |= I2C_CON_MOD(I2C_MODE_TRX); 207 208 writel(con, ®s->con); 209 writel(bytes_xferred, ®s->mrxcnt); 210 writel(I2C_MBRFIEN | I2C_NAKRCVIEN, ®s->ien); 211 212 start = get_timer(0); 213 while (1) { 214 if (readl(®s->ipd) & I2C_NAKRCVIPD) { 215 writel(I2C_NAKRCVIPD, ®s->ipd); 216 err = -EREMOTEIO; 217 } 218 if (readl(®s->ipd) & I2C_MBRFIPD) { 219 writel(I2C_MBRFIPD, ®s->ipd); 220 break; 221 } 222 if (get_timer(start) > I2C_TIMEOUT_MS) { 223 debug("I2C Read Data Timeout\n"); 224 err = -ETIMEDOUT; 225 rk_i2c_show_regs(regs); 226 goto i2c_exit; 227 } 228 udelay(1); 229 } 230 231 for (i = 0; i < words_xferred; i++) { 232 rxdata = readl(®s->rxdata[i]); 233 debug("I2c Read RXDATA[%d] = 0x%x\n", i, rxdata); 234 for (j = 0; j < 4; j++) { 235 if ((i * 4 + j) == bytes_xferred) 236 break; 237 *pbuf++ = (rxdata >> (j * 8)) & 0xff; 238 } 239 } 240 241 bytes_remain_len -= bytes_xferred; 242 snd_chunk = true; 243 debug("I2C Read bytes_remain_len %d\n", bytes_remain_len); 244 } 245 246 i2c_exit: 247 rk_i2c_send_stop_bit(i2c); 248 rk_i2c_disable(i2c); 249 250 return err; 251 } 252 253 static int rk_i2c_write(struct rk_i2c *i2c, uchar chip, uint reg, uint r_len, 254 uchar *buf, uint b_len) 255 { 256 struct i2c_regs *regs = i2c->regs; 257 int err; 258 uchar *pbuf = buf; 259 uint bytes_remain_len = b_len + r_len + 1; 260 uint bytes_xferred = 0; 261 uint words_xferred = 0; 262 ulong start; 263 uint txdata; 264 uint i, j; 265 266 debug("rk_i2c_write: chip = %d, reg = %d, r_len = %d, b_len = %d\n", 267 chip, reg, r_len, b_len); 268 err = rk_i2c_send_start_bit(i2c); 269 if (err) 270 return err; 271 272 while (bytes_remain_len) { 273 if (bytes_remain_len > RK_I2C_FIFO_SIZE) 274 bytes_xferred = RK_I2C_FIFO_SIZE; 275 else 276 bytes_xferred = bytes_remain_len; 277 words_xferred = DIV_ROUND_UP(bytes_xferred, 4); 278 279 for (i = 0; i < words_xferred; i++) { 280 txdata = 0; 281 for (j = 0; j < 4; j++) { 282 if ((i * 4 + j) == bytes_xferred) 283 break; 284 285 if (i == 0 && j == 0 && pbuf == buf) { 286 txdata |= (chip << 1); 287 } else if (i == 0 && j <= r_len && pbuf == buf) { 288 txdata |= (reg & 289 (0xff << ((j - 1) * 8))) << 8; 290 } else { 291 txdata |= (*pbuf++)<<(j * 8); 292 } 293 } 294 writel(txdata, ®s->txdata[i]); 295 debug("I2c Write TXDATA[%d] = 0x%08x\n", i, txdata); 296 } 297 298 writel(I2C_CON_EN | I2C_CON_MOD(I2C_MODE_TX), ®s->con); 299 writel(bytes_xferred, ®s->mtxcnt); 300 writel(I2C_MBTFIEN | I2C_NAKRCVIEN, ®s->ien); 301 302 start = get_timer(0); 303 while (1) { 304 if (readl(®s->ipd) & I2C_NAKRCVIPD) { 305 writel(I2C_NAKRCVIPD, ®s->ipd); 306 err = -EREMOTEIO; 307 } 308 if (readl(®s->ipd) & I2C_MBTFIPD) { 309 writel(I2C_MBTFIPD, ®s->ipd); 310 break; 311 } 312 if (get_timer(start) > I2C_TIMEOUT_MS) { 313 debug("I2C Write Data Timeout\n"); 314 err = -ETIMEDOUT; 315 rk_i2c_show_regs(regs); 316 goto i2c_exit; 317 } 318 udelay(1); 319 } 320 321 bytes_remain_len -= bytes_xferred; 322 debug("I2C Write bytes_remain_len %d\n", bytes_remain_len); 323 } 324 325 i2c_exit: 326 rk_i2c_send_stop_bit(i2c); 327 rk_i2c_disable(i2c); 328 329 return err; 330 } 331 332 static int rockchip_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, 333 int nmsgs) 334 { 335 struct rk_i2c *i2c = dev_get_priv(bus); 336 int ret; 337 338 debug("i2c_xfer: %d messages\n", nmsgs); 339 for (; nmsgs > 0; nmsgs--, msg++) { 340 debug("i2c_xfer: chip=0x%x, len=0x%x\n", msg->addr, msg->len); 341 if (msg->flags & I2C_M_RD) { 342 ret = rk_i2c_read(i2c, msg->addr, 0, 0, msg->buf, 343 msg->len); 344 } else { 345 ret = rk_i2c_write(i2c, msg->addr, 0, 0, msg->buf, 346 msg->len); 347 } 348 if (ret) { 349 debug("i2c_write: error sending\n"); 350 return -EREMOTEIO; 351 } 352 } 353 354 return 0; 355 } 356 357 int rockchip_i2c_set_bus_speed(struct udevice *bus, unsigned int speed) 358 { 359 struct rk_i2c *i2c = dev_get_priv(bus); 360 361 rk_i2c_set_clk(i2c, speed); 362 363 return 0; 364 } 365 366 static int rockchip_i2c_ofdata_to_platdata(struct udevice *bus) 367 { 368 struct rk_i2c *priv = dev_get_priv(bus); 369 int ret; 370 371 ret = clk_get_by_index(bus, 0, &priv->clk); 372 if (ret < 0) { 373 debug("%s: Could not get clock for %s: %d\n", __func__, 374 bus->name, ret); 375 return ret; 376 } 377 378 return 0; 379 } 380 381 static int rockchip_i2c_probe(struct udevice *bus) 382 { 383 struct rk_i2c *priv = dev_get_priv(bus); 384 385 priv->regs = (void *)devfdt_get_addr(bus); 386 387 return 0; 388 } 389 390 static const struct dm_i2c_ops rockchip_i2c_ops = { 391 .xfer = rockchip_i2c_xfer, 392 .set_bus_speed = rockchip_i2c_set_bus_speed, 393 }; 394 395 static const struct udevice_id rockchip_i2c_ids[] = { 396 { .compatible = "rockchip,rk3066-i2c" }, 397 { .compatible = "rockchip,rk3188-i2c" }, 398 { .compatible = "rockchip,rk3288-i2c" }, 399 { .compatible = "rockchip,rk3399-i2c" }, 400 { } 401 }; 402 403 U_BOOT_DRIVER(i2c_rockchip) = { 404 .name = "i2c_rockchip", 405 .id = UCLASS_I2C, 406 .of_match = rockchip_i2c_ids, 407 .ofdata_to_platdata = rockchip_i2c_ofdata_to_platdata, 408 .probe = rockchip_i2c_probe, 409 .priv_auto_alloc_size = sizeof(struct rk_i2c), 410 .ops = &rockchip_i2c_ops, 411 }; 412