1 /* 2 * TI OMAP I2C master mode driver 3 * 4 * Copyright (C) 2003 MontaVista Software, Inc. 5 * Copyright (C) 2005 Nokia Corporation 6 * Copyright (C) 2004 - 2007 Texas Instruments. 7 * 8 * Originally written by MontaVista Software, Inc. 9 * Additional contributions by: 10 * Tony Lindgren <tony@atomide.com> 11 * Imre Deak <imre.deak@nokia.com> 12 * Juha Yrjölä <juha.yrjola@solidboot.com> 13 * Syed Khasim <x0khasim@ti.com> 14 * Nishant Menon <nm@ti.com> 15 * 16 * This program is free software; you can redistribute it and/or modify 17 * it under the terms of the GNU General Public License as published by 18 * the Free Software Foundation; either version 2 of the License, or 19 * (at your option) any later version. 20 * 21 * This program is distributed in the hope that it will be useful, 22 * but WITHOUT ANY WARRANTY; without even the implied warranty of 23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 24 * GNU General Public License for more details. 25 */ 26 27 #include <linux/module.h> 28 #include <linux/delay.h> 29 #include <linux/i2c.h> 30 #include <linux/err.h> 31 #include <linux/interrupt.h> 32 #include <linux/completion.h> 33 #include <linux/platform_device.h> 34 #include <linux/clk.h> 35 #include <linux/io.h> 36 #include <linux/of.h> 37 #include <linux/of_device.h> 38 #include <linux/slab.h> 39 #include <linux/platform_data/i2c-omap.h> 40 #include <linux/pm_runtime.h> 41 #include <linux/pinctrl/consumer.h> 42 43 /* I2C controller revisions */ 44 #define OMAP_I2C_OMAP1_REV_2 0x20 45 46 /* I2C controller revisions present on specific hardware */ 47 #define OMAP_I2C_REV_ON_2430 0x00000036 48 #define OMAP_I2C_REV_ON_3430_3530 0x0000003C 49 #define OMAP_I2C_REV_ON_3630 0x00000040 50 #define OMAP_I2C_REV_ON_4430_PLUS 0x50400002 51 52 /* timeout waiting for the controller to respond */ 53 #define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000)) 54 55 /* timeout for pm runtime autosuspend */ 56 #define OMAP_I2C_PM_TIMEOUT 1000 /* ms */ 57 58 /* timeout for making decision on bus free status */ 59 #define OMAP_I2C_BUS_FREE_TIMEOUT (msecs_to_jiffies(10)) 60 61 /* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */ 62 enum { 63 OMAP_I2C_REV_REG = 0, 64 OMAP_I2C_IE_REG, 65 OMAP_I2C_STAT_REG, 66 OMAP_I2C_IV_REG, 67 OMAP_I2C_WE_REG, 68 OMAP_I2C_SYSS_REG, 69 OMAP_I2C_BUF_REG, 70 OMAP_I2C_CNT_REG, 71 OMAP_I2C_DATA_REG, 72 OMAP_I2C_SYSC_REG, 73 OMAP_I2C_CON_REG, 74 OMAP_I2C_OA_REG, 75 OMAP_I2C_SA_REG, 76 OMAP_I2C_PSC_REG, 77 OMAP_I2C_SCLL_REG, 78 OMAP_I2C_SCLH_REG, 79 OMAP_I2C_SYSTEST_REG, 80 OMAP_I2C_BUFSTAT_REG, 81 /* only on OMAP4430 */ 82 OMAP_I2C_IP_V2_REVNB_LO, 83 OMAP_I2C_IP_V2_REVNB_HI, 84 OMAP_I2C_IP_V2_IRQSTATUS_RAW, 85 OMAP_I2C_IP_V2_IRQENABLE_SET, 86 OMAP_I2C_IP_V2_IRQENABLE_CLR, 87 }; 88 89 /* I2C Interrupt Enable Register (OMAP_I2C_IE): */ 90 #define OMAP_I2C_IE_XDR (1 << 14) /* TX Buffer drain int enable */ 91 #define OMAP_I2C_IE_RDR (1 << 13) /* RX Buffer drain int enable */ 92 #define OMAP_I2C_IE_XRDY (1 << 4) /* TX data ready int enable */ 93 #define OMAP_I2C_IE_RRDY (1 << 3) /* RX data ready int enable */ 94 #define OMAP_I2C_IE_ARDY (1 << 2) /* Access ready int enable */ 95 #define OMAP_I2C_IE_NACK (1 << 1) /* No ack interrupt enable */ 96 #define OMAP_I2C_IE_AL (1 << 0) /* Arbitration lost int ena */ 97 98 /* I2C Status Register (OMAP_I2C_STAT): */ 99 #define OMAP_I2C_STAT_XDR (1 << 14) /* TX Buffer draining */ 100 #define OMAP_I2C_STAT_RDR (1 << 13) /* RX Buffer draining */ 101 #define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */ 102 #define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */ 103 #define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */ 104 #define OMAP_I2C_STAT_AAS (1 << 9) /* Address as slave */ 105 #define OMAP_I2C_STAT_BF (1 << 8) /* Bus Free */ 106 #define OMAP_I2C_STAT_XRDY (1 << 4) /* Transmit data ready */ 107 #define OMAP_I2C_STAT_RRDY (1 << 3) /* Receive data ready */ 108 #define OMAP_I2C_STAT_ARDY (1 << 2) /* Register access ready */ 109 #define OMAP_I2C_STAT_NACK (1 << 1) /* No ack interrupt enable */ 110 #define OMAP_I2C_STAT_AL (1 << 0) /* Arbitration lost int ena */ 111 112 /* I2C WE wakeup enable register */ 113 #define OMAP_I2C_WE_XDR_WE (1 << 14) /* TX drain wakup */ 114 #define OMAP_I2C_WE_RDR_WE (1 << 13) /* RX drain wakeup */ 115 #define OMAP_I2C_WE_AAS_WE (1 << 9) /* Address as slave wakeup*/ 116 #define OMAP_I2C_WE_BF_WE (1 << 8) /* Bus free wakeup */ 117 #define OMAP_I2C_WE_STC_WE (1 << 6) /* Start condition wakeup */ 118 #define OMAP_I2C_WE_GC_WE (1 << 5) /* General call wakeup */ 119 #define OMAP_I2C_WE_DRDY_WE (1 << 3) /* TX/RX data ready wakeup */ 120 #define OMAP_I2C_WE_ARDY_WE (1 << 2) /* Reg access ready wakeup */ 121 #define OMAP_I2C_WE_NACK_WE (1 << 1) /* No acknowledgment wakeup */ 122 #define OMAP_I2C_WE_AL_WE (1 << 0) /* Arbitration lost wakeup */ 123 124 #define OMAP_I2C_WE_ALL (OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \ 125 OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \ 126 OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \ 127 OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \ 128 OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE) 129 130 /* I2C Buffer Configuration Register (OMAP_I2C_BUF): */ 131 #define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */ 132 #define OMAP_I2C_BUF_RXFIF_CLR (1 << 14) /* RX FIFO Clear */ 133 #define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */ 134 #define OMAP_I2C_BUF_TXFIF_CLR (1 << 6) /* TX FIFO Clear */ 135 136 /* I2C Configuration Register (OMAP_I2C_CON): */ 137 #define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */ 138 #define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */ 139 #define OMAP_I2C_CON_OPMODE_HS (1 << 12) /* High Speed support */ 140 #define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */ 141 #define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */ 142 #define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */ 143 #define OMAP_I2C_CON_XA (1 << 8) /* Expand address */ 144 #define OMAP_I2C_CON_RM (1 << 2) /* Repeat mode (master only) */ 145 #define OMAP_I2C_CON_STP (1 << 1) /* Stop cond (master only) */ 146 #define OMAP_I2C_CON_STT (1 << 0) /* Start condition (master) */ 147 148 /* I2C SCL time value when Master */ 149 #define OMAP_I2C_SCLL_HSSCLL 8 150 #define OMAP_I2C_SCLH_HSSCLH 8 151 152 /* I2C System Test Register (OMAP_I2C_SYSTEST): */ 153 #define OMAP_I2C_SYSTEST_ST_EN (1 << 15) /* System test enable */ 154 #define OMAP_I2C_SYSTEST_FREE (1 << 14) /* Free running mode */ 155 #define OMAP_I2C_SYSTEST_TMODE_MASK (3 << 12) /* Test mode select */ 156 #define OMAP_I2C_SYSTEST_TMODE_SHIFT (12) /* Test mode select */ 157 /* Functional mode */ 158 #define OMAP_I2C_SYSTEST_SCL_I_FUNC (1 << 8) /* SCL line input value */ 159 #define OMAP_I2C_SYSTEST_SCL_O_FUNC (1 << 7) /* SCL line output value */ 160 #define OMAP_I2C_SYSTEST_SDA_I_FUNC (1 << 6) /* SDA line input value */ 161 #define OMAP_I2C_SYSTEST_SDA_O_FUNC (1 << 5) /* SDA line output value */ 162 /* SDA/SCL IO mode */ 163 #define OMAP_I2C_SYSTEST_SCL_I (1 << 3) /* SCL line sense in */ 164 #define OMAP_I2C_SYSTEST_SCL_O (1 << 2) /* SCL line drive out */ 165 #define OMAP_I2C_SYSTEST_SDA_I (1 << 1) /* SDA line sense in */ 166 #define OMAP_I2C_SYSTEST_SDA_O (1 << 0) /* SDA line drive out */ 167 168 /* OCP_SYSSTATUS bit definitions */ 169 #define SYSS_RESETDONE_MASK (1 << 0) 170 171 /* OCP_SYSCONFIG bit definitions */ 172 #define SYSC_CLOCKACTIVITY_MASK (0x3 << 8) 173 #define SYSC_SIDLEMODE_MASK (0x3 << 3) 174 #define SYSC_ENAWAKEUP_MASK (1 << 2) 175 #define SYSC_SOFTRESET_MASK (1 << 1) 176 #define SYSC_AUTOIDLE_MASK (1 << 0) 177 178 #define SYSC_IDLEMODE_SMART 0x2 179 #define SYSC_CLOCKACTIVITY_FCLK 0x2 180 181 /* Errata definitions */ 182 #define I2C_OMAP_ERRATA_I207 (1 << 0) 183 #define I2C_OMAP_ERRATA_I462 (1 << 1) 184 185 #define OMAP_I2C_IP_V2_INTERRUPTS_MASK 0x6FFF 186 187 struct omap_i2c_dev { 188 struct device *dev; 189 void __iomem *base; /* virtual */ 190 int irq; 191 int reg_shift; /* bit shift for I2C register addresses */ 192 struct completion cmd_complete; 193 struct resource *ioarea; 194 u32 latency; /* maximum mpu wkup latency */ 195 void (*set_mpu_wkup_lat)(struct device *dev, 196 long latency); 197 u32 speed; /* Speed of bus in kHz */ 198 u32 flags; 199 u16 scheme; 200 u16 cmd_err; 201 u8 *buf; 202 u8 *regs; 203 size_t buf_len; 204 struct i2c_adapter adapter; 205 u8 threshold; 206 u8 fifo_size; /* use as flag and value 207 * fifo_size==0 implies no fifo 208 * if set, should be trsh+1 209 */ 210 u32 rev; 211 unsigned b_hw:1; /* bad h/w fixes */ 212 unsigned bb_valid:1; /* true when BB-bit reflects 213 * the I2C bus state 214 */ 215 unsigned receiver:1; /* true when we're in receiver mode */ 216 u16 iestate; /* Saved interrupt register */ 217 u16 pscstate; 218 u16 scllstate; 219 u16 sclhstate; 220 u16 syscstate; 221 u16 westate; 222 u16 errata; 223 }; 224 225 static const u8 reg_map_ip_v1[] = { 226 [OMAP_I2C_REV_REG] = 0x00, 227 [OMAP_I2C_IE_REG] = 0x01, 228 [OMAP_I2C_STAT_REG] = 0x02, 229 [OMAP_I2C_IV_REG] = 0x03, 230 [OMAP_I2C_WE_REG] = 0x03, 231 [OMAP_I2C_SYSS_REG] = 0x04, 232 [OMAP_I2C_BUF_REG] = 0x05, 233 [OMAP_I2C_CNT_REG] = 0x06, 234 [OMAP_I2C_DATA_REG] = 0x07, 235 [OMAP_I2C_SYSC_REG] = 0x08, 236 [OMAP_I2C_CON_REG] = 0x09, 237 [OMAP_I2C_OA_REG] = 0x0a, 238 [OMAP_I2C_SA_REG] = 0x0b, 239 [OMAP_I2C_PSC_REG] = 0x0c, 240 [OMAP_I2C_SCLL_REG] = 0x0d, 241 [OMAP_I2C_SCLH_REG] = 0x0e, 242 [OMAP_I2C_SYSTEST_REG] = 0x0f, 243 [OMAP_I2C_BUFSTAT_REG] = 0x10, 244 }; 245 246 static const u8 reg_map_ip_v2[] = { 247 [OMAP_I2C_REV_REG] = 0x04, 248 [OMAP_I2C_IE_REG] = 0x2c, 249 [OMAP_I2C_STAT_REG] = 0x28, 250 [OMAP_I2C_IV_REG] = 0x34, 251 [OMAP_I2C_WE_REG] = 0x34, 252 [OMAP_I2C_SYSS_REG] = 0x90, 253 [OMAP_I2C_BUF_REG] = 0x94, 254 [OMAP_I2C_CNT_REG] = 0x98, 255 [OMAP_I2C_DATA_REG] = 0x9c, 256 [OMAP_I2C_SYSC_REG] = 0x10, 257 [OMAP_I2C_CON_REG] = 0xa4, 258 [OMAP_I2C_OA_REG] = 0xa8, 259 [OMAP_I2C_SA_REG] = 0xac, 260 [OMAP_I2C_PSC_REG] = 0xb0, 261 [OMAP_I2C_SCLL_REG] = 0xb4, 262 [OMAP_I2C_SCLH_REG] = 0xb8, 263 [OMAP_I2C_SYSTEST_REG] = 0xbC, 264 [OMAP_I2C_BUFSTAT_REG] = 0xc0, 265 [OMAP_I2C_IP_V2_REVNB_LO] = 0x00, 266 [OMAP_I2C_IP_V2_REVNB_HI] = 0x04, 267 [OMAP_I2C_IP_V2_IRQSTATUS_RAW] = 0x24, 268 [OMAP_I2C_IP_V2_IRQENABLE_SET] = 0x2c, 269 [OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30, 270 }; 271 272 static inline void omap_i2c_write_reg(struct omap_i2c_dev *omap, 273 int reg, u16 val) 274 { 275 writew_relaxed(val, omap->base + 276 (omap->regs[reg] << omap->reg_shift)); 277 } 278 279 static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *omap, int reg) 280 { 281 return readw_relaxed(omap->base + 282 (omap->regs[reg] << omap->reg_shift)); 283 } 284 285 static void __omap_i2c_init(struct omap_i2c_dev *omap) 286 { 287 288 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0); 289 290 /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */ 291 omap_i2c_write_reg(omap, OMAP_I2C_PSC_REG, omap->pscstate); 292 293 /* SCL low and high time values */ 294 omap_i2c_write_reg(omap, OMAP_I2C_SCLL_REG, omap->scllstate); 295 omap_i2c_write_reg(omap, OMAP_I2C_SCLH_REG, omap->sclhstate); 296 if (omap->rev >= OMAP_I2C_REV_ON_3430_3530) 297 omap_i2c_write_reg(omap, OMAP_I2C_WE_REG, omap->westate); 298 299 /* Take the I2C module out of reset: */ 300 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); 301 302 /* 303 * NOTE: right after setting CON_EN, STAT_BB could be 0 while the 304 * bus is busy. It will be changed to 1 on the next IP FCLK clock. 305 * udelay(1) will be enough to fix that. 306 */ 307 308 /* 309 * Don't write to this register if the IE state is 0 as it can 310 * cause deadlock. 311 */ 312 if (omap->iestate) 313 omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, omap->iestate); 314 } 315 316 static int omap_i2c_reset(struct omap_i2c_dev *omap) 317 { 318 unsigned long timeout; 319 u16 sysc; 320 321 if (omap->rev >= OMAP_I2C_OMAP1_REV_2) { 322 sysc = omap_i2c_read_reg(omap, OMAP_I2C_SYSC_REG); 323 324 /* Disable I2C controller before soft reset */ 325 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 326 omap_i2c_read_reg(omap, OMAP_I2C_CON_REG) & 327 ~(OMAP_I2C_CON_EN)); 328 329 omap_i2c_write_reg(omap, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK); 330 /* For some reason we need to set the EN bit before the 331 * reset done bit gets set. */ 332 timeout = jiffies + OMAP_I2C_TIMEOUT; 333 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); 334 while (!(omap_i2c_read_reg(omap, OMAP_I2C_SYSS_REG) & 335 SYSS_RESETDONE_MASK)) { 336 if (time_after(jiffies, timeout)) { 337 dev_warn(omap->dev, "timeout waiting " 338 "for controller reset\n"); 339 return -ETIMEDOUT; 340 } 341 msleep(1); 342 } 343 344 /* SYSC register is cleared by the reset; rewrite it */ 345 omap_i2c_write_reg(omap, OMAP_I2C_SYSC_REG, sysc); 346 347 if (omap->rev > OMAP_I2C_REV_ON_3430_3530) { 348 /* Schedule I2C-bus monitoring on the next transfer */ 349 omap->bb_valid = 0; 350 } 351 } 352 353 return 0; 354 } 355 356 static int omap_i2c_init(struct omap_i2c_dev *omap) 357 { 358 u16 psc = 0, scll = 0, sclh = 0; 359 u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0; 360 unsigned long fclk_rate = 12000000; 361 unsigned long internal_clk = 0; 362 struct clk *fclk; 363 int error; 364 365 if (omap->rev >= OMAP_I2C_REV_ON_3430_3530) { 366 /* 367 * Enabling all wakup sources to stop I2C freezing on 368 * WFI instruction. 369 * REVISIT: Some wkup sources might not be needed. 370 */ 371 omap->westate = OMAP_I2C_WE_ALL; 372 } 373 374 if (omap->flags & OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) { 375 /* 376 * The I2C functional clock is the armxor_ck, so there's 377 * no need to get "armxor_ck" separately. Now, if OMAP2420 378 * always returns 12MHz for the functional clock, we can 379 * do this bit unconditionally. 380 */ 381 fclk = clk_get(omap->dev, "fck"); 382 if (IS_ERR(fclk)) { 383 error = PTR_ERR(fclk); 384 dev_err(omap->dev, "could not get fck: %i\n", error); 385 386 return error; 387 } 388 389 fclk_rate = clk_get_rate(fclk); 390 clk_put(fclk); 391 392 /* TRM for 5912 says the I2C clock must be prescaled to be 393 * between 7 - 12 MHz. The XOR input clock is typically 394 * 12, 13 or 19.2 MHz. So we should have code that produces: 395 * 396 * XOR MHz Divider Prescaler 397 * 12 1 0 398 * 13 2 1 399 * 19.2 2 1 400 */ 401 if (fclk_rate > 12000000) 402 psc = fclk_rate / 12000000; 403 } 404 405 if (!(omap->flags & OMAP_I2C_FLAG_SIMPLE_CLOCK)) { 406 407 /* 408 * HSI2C controller internal clk rate should be 19.2 Mhz for 409 * HS and for all modes on 2430. On 34xx we can use lower rate 410 * to get longer filter period for better noise suppression. 411 * The filter is iclk (fclk for HS) period. 412 */ 413 if (omap->speed > 400 || 414 omap->flags & OMAP_I2C_FLAG_FORCE_19200_INT_CLK) 415 internal_clk = 19200; 416 else if (omap->speed > 100) 417 internal_clk = 9600; 418 else 419 internal_clk = 4000; 420 fclk = clk_get(omap->dev, "fck"); 421 if (IS_ERR(fclk)) { 422 error = PTR_ERR(fclk); 423 dev_err(omap->dev, "could not get fck: %i\n", error); 424 425 return error; 426 } 427 fclk_rate = clk_get_rate(fclk) / 1000; 428 clk_put(fclk); 429 430 /* Compute prescaler divisor */ 431 psc = fclk_rate / internal_clk; 432 psc = psc - 1; 433 434 /* If configured for High Speed */ 435 if (omap->speed > 400) { 436 unsigned long scl; 437 438 /* For first phase of HS mode */ 439 scl = internal_clk / 400; 440 fsscll = scl - (scl / 3) - 7; 441 fssclh = (scl / 3) - 5; 442 443 /* For second phase of HS mode */ 444 scl = fclk_rate / omap->speed; 445 hsscll = scl - (scl / 3) - 7; 446 hssclh = (scl / 3) - 5; 447 } else if (omap->speed > 100) { 448 unsigned long scl; 449 450 /* Fast mode */ 451 scl = internal_clk / omap->speed; 452 fsscll = scl - (scl / 3) - 7; 453 fssclh = (scl / 3) - 5; 454 } else { 455 /* Standard mode */ 456 fsscll = internal_clk / (omap->speed * 2) - 7; 457 fssclh = internal_clk / (omap->speed * 2) - 5; 458 } 459 scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll; 460 sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh; 461 } else { 462 /* Program desired operating rate */ 463 fclk_rate /= (psc + 1) * 1000; 464 if (psc > 2) 465 psc = 2; 466 scll = fclk_rate / (omap->speed * 2) - 7 + psc; 467 sclh = fclk_rate / (omap->speed * 2) - 7 + psc; 468 } 469 470 omap->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY | 471 OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK | 472 OMAP_I2C_IE_AL) | ((omap->fifo_size) ? 473 (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0); 474 475 omap->pscstate = psc; 476 omap->scllstate = scll; 477 omap->sclhstate = sclh; 478 479 if (omap->rev <= OMAP_I2C_REV_ON_3430_3530) { 480 /* Not implemented */ 481 omap->bb_valid = 1; 482 } 483 484 __omap_i2c_init(omap); 485 486 return 0; 487 } 488 489 /* 490 * Try bus recovery, but only if SDA is actually low. 491 */ 492 static int omap_i2c_recover_bus(struct omap_i2c_dev *omap) 493 { 494 u16 systest; 495 496 systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG); 497 if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) && 498 (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC)) 499 return 0; /* bus seems to already be fine */ 500 if (!(systest & OMAP_I2C_SYSTEST_SCL_I_FUNC)) 501 return -EBUSY; /* recovery would not fix SCL */ 502 return i2c_recover_bus(&omap->adapter); 503 } 504 505 /* 506 * Waiting on Bus Busy 507 */ 508 static int omap_i2c_wait_for_bb(struct omap_i2c_dev *omap) 509 { 510 unsigned long timeout; 511 512 timeout = jiffies + OMAP_I2C_TIMEOUT; 513 while (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) { 514 if (time_after(jiffies, timeout)) 515 return omap_i2c_recover_bus(omap); 516 msleep(1); 517 } 518 519 return 0; 520 } 521 522 /* 523 * Wait while BB-bit doesn't reflect the I2C bus state 524 * 525 * In a multimaster environment, after IP software reset, BB-bit value doesn't 526 * correspond to the current bus state. It may happen what BB-bit will be 0, 527 * while the bus is busy due to another I2C master activity. 528 * Here are BB-bit values after reset: 529 * SDA SCL BB NOTES 530 * 0 0 0 1, 2 531 * 1 0 0 1, 2 532 * 0 1 1 533 * 1 1 0 3 534 * Later, if IP detect SDA=0 and SCL=1 (ACK) or SDA 1->0 while SCL=1 (START) 535 * combinations on the bus, it set BB-bit to 1. 536 * If IP detect SDA 0->1 while SCL=1 (STOP) combination on the bus, 537 * it set BB-bit to 0 and BF to 1. 538 * BB and BF bits correctly tracks the bus state while IP is suspended 539 * BB bit became valid on the next FCLK clock after CON_EN bit set 540 * 541 * NOTES: 542 * 1. Any transfer started when BB=0 and bus is busy wouldn't be 543 * completed by IP and results in controller timeout. 544 * 2. Any transfer started when BB=0 and SCL=0 results in IP 545 * starting to drive SDA low. In that case IP corrupt data 546 * on the bus. 547 * 3. Any transfer started in the middle of another master's transfer 548 * results in unpredictable results and data corruption 549 */ 550 static int omap_i2c_wait_for_bb_valid(struct omap_i2c_dev *omap) 551 { 552 unsigned long bus_free_timeout = 0; 553 unsigned long timeout; 554 int bus_free = 0; 555 u16 stat, systest; 556 557 if (omap->bb_valid) 558 return 0; 559 560 timeout = jiffies + OMAP_I2C_TIMEOUT; 561 while (1) { 562 stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); 563 /* 564 * We will see BB or BF event in a case IP had detected any 565 * activity on the I2C bus. Now IP correctly tracks the bus 566 * state. BB-bit value is valid. 567 */ 568 if (stat & (OMAP_I2C_STAT_BB | OMAP_I2C_STAT_BF)) 569 break; 570 571 /* 572 * Otherwise, we must look signals on the bus to make 573 * the right decision. 574 */ 575 systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG); 576 if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) && 577 (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC)) { 578 if (!bus_free) { 579 bus_free_timeout = jiffies + 580 OMAP_I2C_BUS_FREE_TIMEOUT; 581 bus_free = 1; 582 } 583 584 /* 585 * SDA and SCL lines was high for 10 ms without bus 586 * activity detected. The bus is free. Consider 587 * BB-bit value is valid. 588 */ 589 if (time_after(jiffies, bus_free_timeout)) 590 break; 591 } else { 592 bus_free = 0; 593 } 594 595 if (time_after(jiffies, timeout)) { 596 /* 597 * SDA or SCL were low for the entire timeout without 598 * any activity detected. Most likely, a slave is 599 * locking up the bus with no master driving the clock. 600 */ 601 dev_warn(omap->dev, "timeout waiting for bus ready\n"); 602 return omap_i2c_recover_bus(omap); 603 } 604 605 msleep(1); 606 } 607 608 omap->bb_valid = 1; 609 return 0; 610 } 611 612 static void omap_i2c_resize_fifo(struct omap_i2c_dev *omap, u8 size, bool is_rx) 613 { 614 u16 buf; 615 616 if (omap->flags & OMAP_I2C_FLAG_NO_FIFO) 617 return; 618 619 /* 620 * Set up notification threshold based on message size. We're doing 621 * this to try and avoid draining feature as much as possible. Whenever 622 * we have big messages to transfer (bigger than our total fifo size) 623 * then we might use draining feature to transfer the remaining bytes. 624 */ 625 626 omap->threshold = clamp(size, (u8) 1, omap->fifo_size); 627 628 buf = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG); 629 630 if (is_rx) { 631 /* Clear RX Threshold */ 632 buf &= ~(0x3f << 8); 633 buf |= ((omap->threshold - 1) << 8) | OMAP_I2C_BUF_RXFIF_CLR; 634 } else { 635 /* Clear TX Threshold */ 636 buf &= ~0x3f; 637 buf |= (omap->threshold - 1) | OMAP_I2C_BUF_TXFIF_CLR; 638 } 639 640 omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, buf); 641 642 if (omap->rev < OMAP_I2C_REV_ON_3630) 643 omap->b_hw = 1; /* Enable hardware fixes */ 644 645 /* calculate wakeup latency constraint for MPU */ 646 if (omap->set_mpu_wkup_lat != NULL) 647 omap->latency = (1000000 * omap->threshold) / 648 (1000 * omap->speed / 8); 649 } 650 651 /* 652 * Low level master read/write transaction. 653 */ 654 static int omap_i2c_xfer_msg(struct i2c_adapter *adap, 655 struct i2c_msg *msg, int stop) 656 { 657 struct omap_i2c_dev *omap = i2c_get_adapdata(adap); 658 unsigned long timeout; 659 u16 w; 660 661 dev_dbg(omap->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n", 662 msg->addr, msg->len, msg->flags, stop); 663 664 omap->receiver = !!(msg->flags & I2C_M_RD); 665 omap_i2c_resize_fifo(omap, msg->len, omap->receiver); 666 667 omap_i2c_write_reg(omap, OMAP_I2C_SA_REG, msg->addr); 668 669 /* REVISIT: Could the STB bit of I2C_CON be used with probing? */ 670 omap->buf = msg->buf; 671 omap->buf_len = msg->len; 672 673 /* make sure writes to omap->buf_len are ordered */ 674 barrier(); 675 676 omap_i2c_write_reg(omap, OMAP_I2C_CNT_REG, omap->buf_len); 677 678 /* Clear the FIFO Buffers */ 679 w = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG); 680 w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR; 681 omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, w); 682 683 reinit_completion(&omap->cmd_complete); 684 omap->cmd_err = 0; 685 686 w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT; 687 688 /* High speed configuration */ 689 if (omap->speed > 400) 690 w |= OMAP_I2C_CON_OPMODE_HS; 691 692 if (msg->flags & I2C_M_STOP) 693 stop = 1; 694 if (msg->flags & I2C_M_TEN) 695 w |= OMAP_I2C_CON_XA; 696 if (!(msg->flags & I2C_M_RD)) 697 w |= OMAP_I2C_CON_TRX; 698 699 if (!omap->b_hw && stop) 700 w |= OMAP_I2C_CON_STP; 701 /* 702 * NOTE: STAT_BB bit could became 1 here if another master occupy 703 * the bus. IP successfully complete transfer when the bus will be 704 * free again (BB reset to 0). 705 */ 706 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w); 707 708 /* 709 * Don't write stt and stp together on some hardware. 710 */ 711 if (omap->b_hw && stop) { 712 unsigned long delay = jiffies + OMAP_I2C_TIMEOUT; 713 u16 con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG); 714 while (con & OMAP_I2C_CON_STT) { 715 con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG); 716 717 /* Let the user know if i2c is in a bad state */ 718 if (time_after(jiffies, delay)) { 719 dev_err(omap->dev, "controller timed out " 720 "waiting for start condition to finish\n"); 721 return -ETIMEDOUT; 722 } 723 cpu_relax(); 724 } 725 726 w |= OMAP_I2C_CON_STP; 727 w &= ~OMAP_I2C_CON_STT; 728 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w); 729 } 730 731 /* 732 * REVISIT: We should abort the transfer on signals, but the bus goes 733 * into arbitration and we're currently unable to recover from it. 734 */ 735 timeout = wait_for_completion_timeout(&omap->cmd_complete, 736 OMAP_I2C_TIMEOUT); 737 if (timeout == 0) { 738 dev_err(omap->dev, "controller timed out\n"); 739 omap_i2c_reset(omap); 740 __omap_i2c_init(omap); 741 return -ETIMEDOUT; 742 } 743 744 if (likely(!omap->cmd_err)) 745 return 0; 746 747 /* We have an error */ 748 if (omap->cmd_err & (OMAP_I2C_STAT_ROVR | OMAP_I2C_STAT_XUDF)) { 749 omap_i2c_reset(omap); 750 __omap_i2c_init(omap); 751 return -EIO; 752 } 753 754 if (omap->cmd_err & OMAP_I2C_STAT_AL) 755 return -EAGAIN; 756 757 if (omap->cmd_err & OMAP_I2C_STAT_NACK) { 758 if (msg->flags & I2C_M_IGNORE_NAK) 759 return 0; 760 761 w = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG); 762 w |= OMAP_I2C_CON_STP; 763 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w); 764 return -EREMOTEIO; 765 } 766 return -EIO; 767 } 768 769 770 /* 771 * Prepare controller for a transaction and call omap_i2c_xfer_msg 772 * to do the work during IRQ processing. 773 */ 774 static int 775 omap_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 776 { 777 struct omap_i2c_dev *omap = i2c_get_adapdata(adap); 778 int i; 779 int r; 780 781 r = pm_runtime_get_sync(omap->dev); 782 if (r < 0) 783 goto out; 784 785 r = omap_i2c_wait_for_bb_valid(omap); 786 if (r < 0) 787 goto out; 788 789 r = omap_i2c_wait_for_bb(omap); 790 if (r < 0) 791 goto out; 792 793 if (omap->set_mpu_wkup_lat != NULL) 794 omap->set_mpu_wkup_lat(omap->dev, omap->latency); 795 796 for (i = 0; i < num; i++) { 797 r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1))); 798 if (r != 0) 799 break; 800 } 801 802 if (r == 0) 803 r = num; 804 805 omap_i2c_wait_for_bb(omap); 806 807 if (omap->set_mpu_wkup_lat != NULL) 808 omap->set_mpu_wkup_lat(omap->dev, -1); 809 810 out: 811 pm_runtime_mark_last_busy(omap->dev); 812 pm_runtime_put_autosuspend(omap->dev); 813 return r; 814 } 815 816 static u32 817 omap_i2c_func(struct i2c_adapter *adap) 818 { 819 return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) | 820 I2C_FUNC_PROTOCOL_MANGLING; 821 } 822 823 static inline void 824 omap_i2c_complete_cmd(struct omap_i2c_dev *omap, u16 err) 825 { 826 omap->cmd_err |= err; 827 complete(&omap->cmd_complete); 828 } 829 830 static inline void 831 omap_i2c_ack_stat(struct omap_i2c_dev *omap, u16 stat) 832 { 833 omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, stat); 834 } 835 836 static inline void i2c_omap_errata_i207(struct omap_i2c_dev *omap, u16 stat) 837 { 838 /* 839 * I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8) 840 * Not applicable for OMAP4. 841 * Under certain rare conditions, RDR could be set again 842 * when the bus is busy, then ignore the interrupt and 843 * clear the interrupt. 844 */ 845 if (stat & OMAP_I2C_STAT_RDR) { 846 /* Step 1: If RDR is set, clear it */ 847 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR); 848 849 /* Step 2: */ 850 if (!(omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG) 851 & OMAP_I2C_STAT_BB)) { 852 853 /* Step 3: */ 854 if (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG) 855 & OMAP_I2C_STAT_RDR) { 856 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR); 857 dev_dbg(omap->dev, "RDR when bus is busy.\n"); 858 } 859 860 } 861 } 862 } 863 864 /* rev1 devices are apparently only on some 15xx */ 865 #ifdef CONFIG_ARCH_OMAP15XX 866 867 static irqreturn_t 868 omap_i2c_omap1_isr(int this_irq, void *dev_id) 869 { 870 struct omap_i2c_dev *omap = dev_id; 871 u16 iv, w; 872 873 if (pm_runtime_suspended(omap->dev)) 874 return IRQ_NONE; 875 876 iv = omap_i2c_read_reg(omap, OMAP_I2C_IV_REG); 877 switch (iv) { 878 case 0x00: /* None */ 879 break; 880 case 0x01: /* Arbitration lost */ 881 dev_err(omap->dev, "Arbitration lost\n"); 882 omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_AL); 883 break; 884 case 0x02: /* No acknowledgement */ 885 omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_NACK); 886 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP); 887 break; 888 case 0x03: /* Register access ready */ 889 omap_i2c_complete_cmd(omap, 0); 890 break; 891 case 0x04: /* Receive data ready */ 892 if (omap->buf_len) { 893 w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG); 894 *omap->buf++ = w; 895 omap->buf_len--; 896 if (omap->buf_len) { 897 *omap->buf++ = w >> 8; 898 omap->buf_len--; 899 } 900 } else 901 dev_err(omap->dev, "RRDY IRQ while no data requested\n"); 902 break; 903 case 0x05: /* Transmit data ready */ 904 if (omap->buf_len) { 905 w = *omap->buf++; 906 omap->buf_len--; 907 if (omap->buf_len) { 908 w |= *omap->buf++ << 8; 909 omap->buf_len--; 910 } 911 omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w); 912 } else 913 dev_err(omap->dev, "XRDY IRQ while no data to send\n"); 914 break; 915 default: 916 return IRQ_NONE; 917 } 918 919 return IRQ_HANDLED; 920 } 921 #else 922 #define omap_i2c_omap1_isr NULL 923 #endif 924 925 /* 926 * OMAP3430 Errata i462: When an XRDY/XDR is hit, wait for XUDF before writing 927 * data to DATA_REG. Otherwise some data bytes can be lost while transferring 928 * them from the memory to the I2C interface. 929 */ 930 static int errata_omap3_i462(struct omap_i2c_dev *omap) 931 { 932 unsigned long timeout = 10000; 933 u16 stat; 934 935 do { 936 stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); 937 if (stat & OMAP_I2C_STAT_XUDF) 938 break; 939 940 if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) { 941 omap_i2c_ack_stat(omap, (OMAP_I2C_STAT_XRDY | 942 OMAP_I2C_STAT_XDR)); 943 if (stat & OMAP_I2C_STAT_NACK) { 944 omap->cmd_err |= OMAP_I2C_STAT_NACK; 945 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK); 946 } 947 948 if (stat & OMAP_I2C_STAT_AL) { 949 dev_err(omap->dev, "Arbitration lost\n"); 950 omap->cmd_err |= OMAP_I2C_STAT_AL; 951 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL); 952 } 953 954 return -EIO; 955 } 956 957 cpu_relax(); 958 } while (--timeout); 959 960 if (!timeout) { 961 dev_err(omap->dev, "timeout waiting on XUDF bit\n"); 962 return 0; 963 } 964 965 return 0; 966 } 967 968 static void omap_i2c_receive_data(struct omap_i2c_dev *omap, u8 num_bytes, 969 bool is_rdr) 970 { 971 u16 w; 972 973 while (num_bytes--) { 974 w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG); 975 *omap->buf++ = w; 976 omap->buf_len--; 977 978 /* 979 * Data reg in 2430, omap3 and 980 * omap4 is 8 bit wide 981 */ 982 if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) { 983 *omap->buf++ = w >> 8; 984 omap->buf_len--; 985 } 986 } 987 } 988 989 static int omap_i2c_transmit_data(struct omap_i2c_dev *omap, u8 num_bytes, 990 bool is_xdr) 991 { 992 u16 w; 993 994 while (num_bytes--) { 995 w = *omap->buf++; 996 omap->buf_len--; 997 998 /* 999 * Data reg in 2430, omap3 and 1000 * omap4 is 8 bit wide 1001 */ 1002 if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) { 1003 w |= *omap->buf++ << 8; 1004 omap->buf_len--; 1005 } 1006 1007 if (omap->errata & I2C_OMAP_ERRATA_I462) { 1008 int ret; 1009 1010 ret = errata_omap3_i462(omap); 1011 if (ret < 0) 1012 return ret; 1013 } 1014 1015 omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w); 1016 } 1017 1018 return 0; 1019 } 1020 1021 static irqreturn_t 1022 omap_i2c_isr(int irq, void *dev_id) 1023 { 1024 struct omap_i2c_dev *omap = dev_id; 1025 irqreturn_t ret = IRQ_HANDLED; 1026 u16 mask; 1027 u16 stat; 1028 1029 stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); 1030 mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG); 1031 1032 if (stat & mask) 1033 ret = IRQ_WAKE_THREAD; 1034 1035 return ret; 1036 } 1037 1038 static irqreturn_t 1039 omap_i2c_isr_thread(int this_irq, void *dev_id) 1040 { 1041 struct omap_i2c_dev *omap = dev_id; 1042 u16 bits; 1043 u16 stat; 1044 int err = 0, count = 0; 1045 1046 do { 1047 bits = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG); 1048 stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); 1049 stat &= bits; 1050 1051 /* If we're in receiver mode, ignore XDR/XRDY */ 1052 if (omap->receiver) 1053 stat &= ~(OMAP_I2C_STAT_XDR | OMAP_I2C_STAT_XRDY); 1054 else 1055 stat &= ~(OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_RRDY); 1056 1057 if (!stat) { 1058 /* my work here is done */ 1059 goto out; 1060 } 1061 1062 dev_dbg(omap->dev, "IRQ (ISR = 0x%04x)\n", stat); 1063 if (count++ == 100) { 1064 dev_warn(omap->dev, "Too much work in one IRQ\n"); 1065 break; 1066 } 1067 1068 if (stat & OMAP_I2C_STAT_NACK) { 1069 err |= OMAP_I2C_STAT_NACK; 1070 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK); 1071 } 1072 1073 if (stat & OMAP_I2C_STAT_AL) { 1074 dev_err(omap->dev, "Arbitration lost\n"); 1075 err |= OMAP_I2C_STAT_AL; 1076 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL); 1077 } 1078 1079 /* 1080 * ProDB0017052: Clear ARDY bit twice 1081 */ 1082 if (stat & OMAP_I2C_STAT_ARDY) 1083 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ARDY); 1084 1085 if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK | 1086 OMAP_I2C_STAT_AL)) { 1087 omap_i2c_ack_stat(omap, (OMAP_I2C_STAT_RRDY | 1088 OMAP_I2C_STAT_RDR | 1089 OMAP_I2C_STAT_XRDY | 1090 OMAP_I2C_STAT_XDR | 1091 OMAP_I2C_STAT_ARDY)); 1092 break; 1093 } 1094 1095 if (stat & OMAP_I2C_STAT_RDR) { 1096 u8 num_bytes = 1; 1097 1098 if (omap->fifo_size) 1099 num_bytes = omap->buf_len; 1100 1101 if (omap->errata & I2C_OMAP_ERRATA_I207) { 1102 i2c_omap_errata_i207(omap, stat); 1103 num_bytes = (omap_i2c_read_reg(omap, 1104 OMAP_I2C_BUFSTAT_REG) >> 8) & 0x3F; 1105 } 1106 1107 omap_i2c_receive_data(omap, num_bytes, true); 1108 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR); 1109 continue; 1110 } 1111 1112 if (stat & OMAP_I2C_STAT_RRDY) { 1113 u8 num_bytes = 1; 1114 1115 if (omap->threshold) 1116 num_bytes = omap->threshold; 1117 1118 omap_i2c_receive_data(omap, num_bytes, false); 1119 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RRDY); 1120 continue; 1121 } 1122 1123 if (stat & OMAP_I2C_STAT_XDR) { 1124 u8 num_bytes = 1; 1125 int ret; 1126 1127 if (omap->fifo_size) 1128 num_bytes = omap->buf_len; 1129 1130 ret = omap_i2c_transmit_data(omap, num_bytes, true); 1131 if (ret < 0) 1132 break; 1133 1134 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XDR); 1135 continue; 1136 } 1137 1138 if (stat & OMAP_I2C_STAT_XRDY) { 1139 u8 num_bytes = 1; 1140 int ret; 1141 1142 if (omap->threshold) 1143 num_bytes = omap->threshold; 1144 1145 ret = omap_i2c_transmit_data(omap, num_bytes, false); 1146 if (ret < 0) 1147 break; 1148 1149 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XRDY); 1150 continue; 1151 } 1152 1153 if (stat & OMAP_I2C_STAT_ROVR) { 1154 dev_err(omap->dev, "Receive overrun\n"); 1155 err |= OMAP_I2C_STAT_ROVR; 1156 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ROVR); 1157 break; 1158 } 1159 1160 if (stat & OMAP_I2C_STAT_XUDF) { 1161 dev_err(omap->dev, "Transmit underflow\n"); 1162 err |= OMAP_I2C_STAT_XUDF; 1163 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XUDF); 1164 break; 1165 } 1166 } while (stat); 1167 1168 omap_i2c_complete_cmd(omap, err); 1169 1170 out: 1171 return IRQ_HANDLED; 1172 } 1173 1174 static const struct i2c_algorithm omap_i2c_algo = { 1175 .master_xfer = omap_i2c_xfer, 1176 .functionality = omap_i2c_func, 1177 }; 1178 1179 static const struct i2c_adapter_quirks omap_i2c_quirks = { 1180 .flags = I2C_AQ_NO_ZERO_LEN, 1181 }; 1182 1183 #ifdef CONFIG_OF 1184 static struct omap_i2c_bus_platform_data omap2420_pdata = { 1185 .rev = OMAP_I2C_IP_VERSION_1, 1186 .flags = OMAP_I2C_FLAG_NO_FIFO | 1187 OMAP_I2C_FLAG_SIMPLE_CLOCK | 1188 OMAP_I2C_FLAG_16BIT_DATA_REG | 1189 OMAP_I2C_FLAG_BUS_SHIFT_2, 1190 }; 1191 1192 static struct omap_i2c_bus_platform_data omap2430_pdata = { 1193 .rev = OMAP_I2C_IP_VERSION_1, 1194 .flags = OMAP_I2C_FLAG_BUS_SHIFT_2 | 1195 OMAP_I2C_FLAG_FORCE_19200_INT_CLK, 1196 }; 1197 1198 static struct omap_i2c_bus_platform_data omap3_pdata = { 1199 .rev = OMAP_I2C_IP_VERSION_1, 1200 .flags = OMAP_I2C_FLAG_BUS_SHIFT_2, 1201 }; 1202 1203 static struct omap_i2c_bus_platform_data omap4_pdata = { 1204 .rev = OMAP_I2C_IP_VERSION_2, 1205 }; 1206 1207 static const struct of_device_id omap_i2c_of_match[] = { 1208 { 1209 .compatible = "ti,omap4-i2c", 1210 .data = &omap4_pdata, 1211 }, 1212 { 1213 .compatible = "ti,omap3-i2c", 1214 .data = &omap3_pdata, 1215 }, 1216 { 1217 .compatible = "ti,omap2430-i2c", 1218 .data = &omap2430_pdata, 1219 }, 1220 { 1221 .compatible = "ti,omap2420-i2c", 1222 .data = &omap2420_pdata, 1223 }, 1224 { }, 1225 }; 1226 MODULE_DEVICE_TABLE(of, omap_i2c_of_match); 1227 #endif 1228 1229 #define OMAP_I2C_SCHEME(rev) ((rev & 0xc000) >> 14) 1230 1231 #define OMAP_I2C_REV_SCHEME_0_MAJOR(rev) (rev >> 4) 1232 #define OMAP_I2C_REV_SCHEME_0_MINOR(rev) (rev & 0xf) 1233 1234 #define OMAP_I2C_REV_SCHEME_1_MAJOR(rev) ((rev & 0x0700) >> 7) 1235 #define OMAP_I2C_REV_SCHEME_1_MINOR(rev) (rev & 0x1f) 1236 #define OMAP_I2C_SCHEME_0 0 1237 #define OMAP_I2C_SCHEME_1 1 1238 1239 static int omap_i2c_get_scl(struct i2c_adapter *adap) 1240 { 1241 struct omap_i2c_dev *dev = i2c_get_adapdata(adap); 1242 u32 reg; 1243 1244 reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); 1245 1246 return reg & OMAP_I2C_SYSTEST_SCL_I_FUNC; 1247 } 1248 1249 static int omap_i2c_get_sda(struct i2c_adapter *adap) 1250 { 1251 struct omap_i2c_dev *dev = i2c_get_adapdata(adap); 1252 u32 reg; 1253 1254 reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); 1255 1256 return reg & OMAP_I2C_SYSTEST_SDA_I_FUNC; 1257 } 1258 1259 static void omap_i2c_set_scl(struct i2c_adapter *adap, int val) 1260 { 1261 struct omap_i2c_dev *dev = i2c_get_adapdata(adap); 1262 u32 reg; 1263 1264 reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); 1265 if (val) 1266 reg |= OMAP_I2C_SYSTEST_SCL_O; 1267 else 1268 reg &= ~OMAP_I2C_SYSTEST_SCL_O; 1269 omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg); 1270 } 1271 1272 static void omap_i2c_prepare_recovery(struct i2c_adapter *adap) 1273 { 1274 struct omap_i2c_dev *dev = i2c_get_adapdata(adap); 1275 u32 reg; 1276 1277 reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); 1278 /* enable test mode */ 1279 reg |= OMAP_I2C_SYSTEST_ST_EN; 1280 /* select SDA/SCL IO mode */ 1281 reg |= 3 << OMAP_I2C_SYSTEST_TMODE_SHIFT; 1282 /* set SCL to high-impedance state (reset value is 0) */ 1283 reg |= OMAP_I2C_SYSTEST_SCL_O; 1284 /* set SDA to high-impedance state (reset value is 0) */ 1285 reg |= OMAP_I2C_SYSTEST_SDA_O; 1286 omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg); 1287 } 1288 1289 static void omap_i2c_unprepare_recovery(struct i2c_adapter *adap) 1290 { 1291 struct omap_i2c_dev *dev = i2c_get_adapdata(adap); 1292 u32 reg; 1293 1294 reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); 1295 /* restore reset values */ 1296 reg &= ~OMAP_I2C_SYSTEST_ST_EN; 1297 reg &= ~OMAP_I2C_SYSTEST_TMODE_MASK; 1298 reg &= ~OMAP_I2C_SYSTEST_SCL_O; 1299 reg &= ~OMAP_I2C_SYSTEST_SDA_O; 1300 omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg); 1301 } 1302 1303 static struct i2c_bus_recovery_info omap_i2c_bus_recovery_info = { 1304 .get_scl = omap_i2c_get_scl, 1305 .get_sda = omap_i2c_get_sda, 1306 .set_scl = omap_i2c_set_scl, 1307 .prepare_recovery = omap_i2c_prepare_recovery, 1308 .unprepare_recovery = omap_i2c_unprepare_recovery, 1309 .recover_bus = i2c_generic_scl_recovery, 1310 }; 1311 1312 static int 1313 omap_i2c_probe(struct platform_device *pdev) 1314 { 1315 struct omap_i2c_dev *omap; 1316 struct i2c_adapter *adap; 1317 struct resource *mem; 1318 const struct omap_i2c_bus_platform_data *pdata = 1319 dev_get_platdata(&pdev->dev); 1320 struct device_node *node = pdev->dev.of_node; 1321 const struct of_device_id *match; 1322 int irq; 1323 int r; 1324 u32 rev; 1325 u16 minor, major; 1326 1327 irq = platform_get_irq(pdev, 0); 1328 if (irq < 0) { 1329 dev_err(&pdev->dev, "no irq resource?\n"); 1330 return irq; 1331 } 1332 1333 omap = devm_kzalloc(&pdev->dev, sizeof(struct omap_i2c_dev), GFP_KERNEL); 1334 if (!omap) 1335 return -ENOMEM; 1336 1337 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 1338 omap->base = devm_ioremap_resource(&pdev->dev, mem); 1339 if (IS_ERR(omap->base)) 1340 return PTR_ERR(omap->base); 1341 1342 match = of_match_device(of_match_ptr(omap_i2c_of_match), &pdev->dev); 1343 if (match) { 1344 u32 freq = 100000; /* default to 100000 Hz */ 1345 1346 pdata = match->data; 1347 omap->flags = pdata->flags; 1348 1349 of_property_read_u32(node, "clock-frequency", &freq); 1350 /* convert DT freq value in Hz into kHz for speed */ 1351 omap->speed = freq / 1000; 1352 } else if (pdata != NULL) { 1353 omap->speed = pdata->clkrate; 1354 omap->flags = pdata->flags; 1355 omap->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat; 1356 } 1357 1358 omap->dev = &pdev->dev; 1359 omap->irq = irq; 1360 1361 platform_set_drvdata(pdev, omap); 1362 init_completion(&omap->cmd_complete); 1363 1364 omap->reg_shift = (omap->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3; 1365 1366 pm_runtime_enable(omap->dev); 1367 pm_runtime_set_autosuspend_delay(omap->dev, OMAP_I2C_PM_TIMEOUT); 1368 pm_runtime_use_autosuspend(omap->dev); 1369 1370 r = pm_runtime_get_sync(omap->dev); 1371 if (r < 0) 1372 goto err_free_mem; 1373 1374 /* 1375 * Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2. 1376 * On omap1/3/2 Offset 4 is IE Reg the bit [15:14] is 0 at reset. 1377 * Also since the omap_i2c_read_reg uses reg_map_ip_* a 1378 * readw_relaxed is done. 1379 */ 1380 rev = readw_relaxed(omap->base + 0x04); 1381 1382 omap->scheme = OMAP_I2C_SCHEME(rev); 1383 switch (omap->scheme) { 1384 case OMAP_I2C_SCHEME_0: 1385 omap->regs = (u8 *)reg_map_ip_v1; 1386 omap->rev = omap_i2c_read_reg(omap, OMAP_I2C_REV_REG); 1387 minor = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev); 1388 major = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev); 1389 break; 1390 case OMAP_I2C_SCHEME_1: 1391 /* FALLTHROUGH */ 1392 default: 1393 omap->regs = (u8 *)reg_map_ip_v2; 1394 rev = (rev << 16) | 1395 omap_i2c_read_reg(omap, OMAP_I2C_IP_V2_REVNB_LO); 1396 minor = OMAP_I2C_REV_SCHEME_1_MINOR(rev); 1397 major = OMAP_I2C_REV_SCHEME_1_MAJOR(rev); 1398 omap->rev = rev; 1399 } 1400 1401 omap->errata = 0; 1402 1403 if (omap->rev >= OMAP_I2C_REV_ON_2430 && 1404 omap->rev < OMAP_I2C_REV_ON_4430_PLUS) 1405 omap->errata |= I2C_OMAP_ERRATA_I207; 1406 1407 if (omap->rev <= OMAP_I2C_REV_ON_3430_3530) 1408 omap->errata |= I2C_OMAP_ERRATA_I462; 1409 1410 if (!(omap->flags & OMAP_I2C_FLAG_NO_FIFO)) { 1411 u16 s; 1412 1413 /* Set up the fifo size - Get total size */ 1414 s = (omap_i2c_read_reg(omap, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3; 1415 omap->fifo_size = 0x8 << s; 1416 1417 /* 1418 * Set up notification threshold as half the total available 1419 * size. This is to ensure that we can handle the status on int 1420 * call back latencies. 1421 */ 1422 1423 omap->fifo_size = (omap->fifo_size / 2); 1424 1425 if (omap->rev < OMAP_I2C_REV_ON_3630) 1426 omap->b_hw = 1; /* Enable hardware fixes */ 1427 1428 /* calculate wakeup latency constraint for MPU */ 1429 if (omap->set_mpu_wkup_lat != NULL) 1430 omap->latency = (1000000 * omap->fifo_size) / 1431 (1000 * omap->speed / 8); 1432 } 1433 1434 /* reset ASAP, clearing any IRQs */ 1435 omap_i2c_init(omap); 1436 1437 if (omap->rev < OMAP_I2C_OMAP1_REV_2) 1438 r = devm_request_irq(&pdev->dev, omap->irq, omap_i2c_omap1_isr, 1439 IRQF_NO_SUSPEND, pdev->name, omap); 1440 else 1441 r = devm_request_threaded_irq(&pdev->dev, omap->irq, 1442 omap_i2c_isr, omap_i2c_isr_thread, 1443 IRQF_NO_SUSPEND | IRQF_ONESHOT, 1444 pdev->name, omap); 1445 1446 if (r) { 1447 dev_err(omap->dev, "failure requesting irq %i\n", omap->irq); 1448 goto err_unuse_clocks; 1449 } 1450 1451 adap = &omap->adapter; 1452 i2c_set_adapdata(adap, omap); 1453 adap->owner = THIS_MODULE; 1454 adap->class = I2C_CLASS_DEPRECATED; 1455 strlcpy(adap->name, "OMAP I2C adapter", sizeof(adap->name)); 1456 adap->algo = &omap_i2c_algo; 1457 adap->quirks = &omap_i2c_quirks; 1458 adap->dev.parent = &pdev->dev; 1459 adap->dev.of_node = pdev->dev.of_node; 1460 adap->bus_recovery_info = &omap_i2c_bus_recovery_info; 1461 1462 /* i2c device drivers may be active on return from add_adapter() */ 1463 adap->nr = pdev->id; 1464 r = i2c_add_numbered_adapter(adap); 1465 if (r) 1466 goto err_unuse_clocks; 1467 1468 dev_info(omap->dev, "bus %d rev%d.%d at %d kHz\n", adap->nr, 1469 major, minor, omap->speed); 1470 1471 pm_runtime_mark_last_busy(omap->dev); 1472 pm_runtime_put_autosuspend(omap->dev); 1473 1474 return 0; 1475 1476 err_unuse_clocks: 1477 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0); 1478 pm_runtime_dont_use_autosuspend(omap->dev); 1479 pm_runtime_put_sync(omap->dev); 1480 pm_runtime_disable(&pdev->dev); 1481 err_free_mem: 1482 1483 return r; 1484 } 1485 1486 static int omap_i2c_remove(struct platform_device *pdev) 1487 { 1488 struct omap_i2c_dev *omap = platform_get_drvdata(pdev); 1489 int ret; 1490 1491 i2c_del_adapter(&omap->adapter); 1492 ret = pm_runtime_get_sync(&pdev->dev); 1493 if (ret < 0) 1494 return ret; 1495 1496 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0); 1497 pm_runtime_dont_use_autosuspend(&pdev->dev); 1498 pm_runtime_put_sync(&pdev->dev); 1499 pm_runtime_disable(&pdev->dev); 1500 return 0; 1501 } 1502 1503 static int __maybe_unused omap_i2c_runtime_suspend(struct device *dev) 1504 { 1505 struct omap_i2c_dev *omap = dev_get_drvdata(dev); 1506 1507 omap->iestate = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG); 1508 1509 if (omap->scheme == OMAP_I2C_SCHEME_0) 1510 omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, 0); 1511 else 1512 omap_i2c_write_reg(omap, OMAP_I2C_IP_V2_IRQENABLE_CLR, 1513 OMAP_I2C_IP_V2_INTERRUPTS_MASK); 1514 1515 if (omap->rev < OMAP_I2C_OMAP1_REV_2) { 1516 omap_i2c_read_reg(omap, OMAP_I2C_IV_REG); /* Read clears */ 1517 } else { 1518 omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, omap->iestate); 1519 1520 /* Flush posted write */ 1521 omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); 1522 } 1523 1524 pinctrl_pm_select_sleep_state(dev); 1525 1526 return 0; 1527 } 1528 1529 static int __maybe_unused omap_i2c_runtime_resume(struct device *dev) 1530 { 1531 struct omap_i2c_dev *omap = dev_get_drvdata(dev); 1532 1533 pinctrl_pm_select_default_state(dev); 1534 1535 if (!omap->regs) 1536 return 0; 1537 1538 __omap_i2c_init(omap); 1539 1540 return 0; 1541 } 1542 1543 static const struct dev_pm_ops omap_i2c_pm_ops = { 1544 SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 1545 pm_runtime_force_resume) 1546 SET_RUNTIME_PM_OPS(omap_i2c_runtime_suspend, 1547 omap_i2c_runtime_resume, NULL) 1548 }; 1549 1550 static struct platform_driver omap_i2c_driver = { 1551 .probe = omap_i2c_probe, 1552 .remove = omap_i2c_remove, 1553 .driver = { 1554 .name = "omap_i2c", 1555 .pm = &omap_i2c_pm_ops, 1556 .of_match_table = of_match_ptr(omap_i2c_of_match), 1557 }, 1558 }; 1559 1560 /* I2C may be needed to bring up other drivers */ 1561 static int __init 1562 omap_i2c_init_driver(void) 1563 { 1564 return platform_driver_register(&omap_i2c_driver); 1565 } 1566 subsys_initcall(omap_i2c_init_driver); 1567 1568 static void __exit omap_i2c_exit_driver(void) 1569 { 1570 platform_driver_unregister(&omap_i2c_driver); 1571 } 1572 module_exit(omap_i2c_exit_driver); 1573 1574 MODULE_AUTHOR("MontaVista Software, Inc. (and others)"); 1575 MODULE_DESCRIPTION("TI OMAP I2C bus adapter"); 1576 MODULE_LICENSE("GPL"); 1577 MODULE_ALIAS("platform:omap_i2c"); 1578