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i2c-omap.c
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linux-6.19.14/drivers/i2c/busses/i2c-omap.c
1// SPDX-License-Identifier: GPL-2.0-or-later 2/* 3 * TI OMAP I2C master mode driver 4 * 5 * Copyright (C) 2003 MontaVista Software, Inc. 6 * Copyright (C) 2005 Nokia Corporation 7 * Copyright (C) 2004 - 2007 Texas Instruments. 8 * 9 * Originally written by MontaVista Software, Inc. 10 * Additional contributions by: 11 * Tony Lindgren <tony@atomide.com> 12 * Imre Deak <imre.deak@nokia.com> 13 * Juha Yrjölä <juha.yrjola@solidboot.com> 14 * Syed Khasim <x0khasim@ti.com> 15 * Nishant Menon <nm@ti.com> 16 */ 17 18#include <linux/module.h> 19#include <linux/delay.h> 20#include <linux/i2c.h> 21#include <linux/err.h> 22#include <linux/interrupt.h> 23#include <linux/completion.h> 24#include <linux/platform_device.h> 25#include <linux/clk.h> 26#include <linux/io.h> 27#include <linux/mux/consumer.h> 28#include <linux/of.h> 29#include <linux/slab.h> 30#include <linux/platform_data/i2c-omap.h> 31#include <linux/pm_runtime.h> 32#include <linux/pinctrl/consumer.h> 33#include <linux/property.h> 34 35/* I2C controller revisions */ 36#define OMAP_I2C_OMAP1_REV_2 0x20 37 38/* I2C controller revisions present on specific hardware */ 39#define OMAP_I2C_REV_ON_2430 0x00000036 40#define OMAP_I2C_REV_ON_3430_3530 0x0000003C 41#define OMAP_I2C_REV_ON_3630 0x00000040 42#define OMAP_I2C_REV_ON_4430_PLUS 0x50400002 43 44/* timeout waiting for the controller to respond */ 45#define OMAP_I2C_TIMEOUT (msecs_to_jiffies(1000)) 46 47/* timeout for pm runtime autosuspend */ 48#define OMAP_I2C_PM_TIMEOUT 1000 /* ms */ 49 50/* timeout for making decision on bus free status */ 51#define OMAP_I2C_BUS_FREE_TIMEOUT (msecs_to_jiffies(10)) 52 53/* For OMAP3 I2C_IV has changed to I2C_WE (wakeup enable) */ 54enum { 55 OMAP_I2C_REV_REG = 0, 56 OMAP_I2C_IE_REG, 57 OMAP_I2C_STAT_REG, 58 OMAP_I2C_IV_REG, 59 OMAP_I2C_WE_REG, 60 OMAP_I2C_SYSS_REG, 61 OMAP_I2C_BUF_REG, 62 OMAP_I2C_CNT_REG, 63 OMAP_I2C_DATA_REG, 64 OMAP_I2C_SYSC_REG, 65 OMAP_I2C_CON_REG, 66 OMAP_I2C_OA_REG, 67 OMAP_I2C_SA_REG, 68 OMAP_I2C_PSC_REG, 69 OMAP_I2C_SCLL_REG, 70 OMAP_I2C_SCLH_REG, 71 OMAP_I2C_SYSTEST_REG, 72 OMAP_I2C_BUFSTAT_REG, 73 /* only on OMAP4430 */ 74 OMAP_I2C_IP_V2_REVNB_LO, 75 OMAP_I2C_IP_V2_REVNB_HI, 76 OMAP_I2C_IP_V2_IRQSTATUS_RAW, 77 OMAP_I2C_IP_V2_IRQENABLE_SET, 78 OMAP_I2C_IP_V2_IRQENABLE_CLR, 79}; 80 81/* I2C Interrupt Enable Register (OMAP_I2C_IE): */ 82#define OMAP_I2C_IE_XDR (1 << 14) /* TX Buffer drain int enable */ 83#define OMAP_I2C_IE_RDR (1 << 13) /* RX Buffer drain int enable */ 84#define OMAP_I2C_IE_XRDY (1 << 4) /* TX data ready int enable */ 85#define OMAP_I2C_IE_RRDY (1 << 3) /* RX data ready int enable */ 86#define OMAP_I2C_IE_ARDY (1 << 2) /* Access ready int enable */ 87#define OMAP_I2C_IE_NACK (1 << 1) /* No ack interrupt enable */ 88#define OMAP_I2C_IE_AL (1 << 0) /* Arbitration lost int ena */ 89 90/* I2C Status Register (OMAP_I2C_STAT): */ 91#define OMAP_I2C_STAT_XDR (1 << 14) /* TX Buffer draining */ 92#define OMAP_I2C_STAT_RDR (1 << 13) /* RX Buffer draining */ 93#define OMAP_I2C_STAT_BB (1 << 12) /* Bus busy */ 94#define OMAP_I2C_STAT_ROVR (1 << 11) /* Receive overrun */ 95#define OMAP_I2C_STAT_XUDF (1 << 10) /* Transmit underflow */ 96#define OMAP_I2C_STAT_AAS (1 << 9) /* Address as slave */ 97#define OMAP_I2C_STAT_BF (1 << 8) /* Bus Free */ 98#define OMAP_I2C_STAT_XRDY (1 << 4) /* Transmit data ready */ 99#define OMAP_I2C_STAT_RRDY (1 << 3) /* Receive data ready */ 100#define OMAP_I2C_STAT_ARDY (1 << 2) /* Register access ready */ 101#define OMAP_I2C_STAT_NACK (1 << 1) /* No ack interrupt enable */ 102#define OMAP_I2C_STAT_AL (1 << 0) /* Arbitration lost int ena */ 103 104/* I2C WE wakeup enable register */ 105#define OMAP_I2C_WE_XDR_WE (1 << 14) /* TX drain wakup */ 106#define OMAP_I2C_WE_RDR_WE (1 << 13) /* RX drain wakeup */ 107#define OMAP_I2C_WE_AAS_WE (1 << 9) /* Address as slave wakeup*/ 108#define OMAP_I2C_WE_BF_WE (1 << 8) /* Bus free wakeup */ 109#define OMAP_I2C_WE_STC_WE (1 << 6) /* Start condition wakeup */ 110#define OMAP_I2C_WE_GC_WE (1 << 5) /* General call wakeup */ 111#define OMAP_I2C_WE_DRDY_WE (1 << 3) /* TX/RX data ready wakeup */ 112#define OMAP_I2C_WE_ARDY_WE (1 << 2) /* Reg access ready wakeup */ 113#define OMAP_I2C_WE_NACK_WE (1 << 1) /* No acknowledgment wakeup */ 114#define OMAP_I2C_WE_AL_WE (1 << 0) /* Arbitration lost wakeup */ 115 116#define OMAP_I2C_WE_ALL (OMAP_I2C_WE_XDR_WE | OMAP_I2C_WE_RDR_WE | \ 117 OMAP_I2C_WE_AAS_WE | OMAP_I2C_WE_BF_WE | \ 118 OMAP_I2C_WE_STC_WE | OMAP_I2C_WE_GC_WE | \ 119 OMAP_I2C_WE_DRDY_WE | OMAP_I2C_WE_ARDY_WE | \ 120 OMAP_I2C_WE_NACK_WE | OMAP_I2C_WE_AL_WE) 121 122/* I2C Buffer Configuration Register (OMAP_I2C_BUF): */ 123#define OMAP_I2C_BUF_RDMA_EN (1 << 15) /* RX DMA channel enable */ 124#define OMAP_I2C_BUF_RXFIF_CLR (1 << 14) /* RX FIFO Clear */ 125#define OMAP_I2C_BUF_XDMA_EN (1 << 7) /* TX DMA channel enable */ 126#define OMAP_I2C_BUF_TXFIF_CLR (1 << 6) /* TX FIFO Clear */ 127 128/* I2C Configuration Register (OMAP_I2C_CON): */ 129#define OMAP_I2C_CON_EN (1 << 15) /* I2C module enable */ 130#define OMAP_I2C_CON_BE (1 << 14) /* Big endian mode */ 131#define OMAP_I2C_CON_OPMODE_HS (1 << 12) /* High Speed support */ 132#define OMAP_I2C_CON_STB (1 << 11) /* Start byte mode (master) */ 133#define OMAP_I2C_CON_MST (1 << 10) /* Master/slave mode */ 134#define OMAP_I2C_CON_TRX (1 << 9) /* TX/RX mode (master only) */ 135#define OMAP_I2C_CON_XA (1 << 8) /* Expand address */ 136#define OMAP_I2C_CON_RM (1 << 2) /* Repeat mode (master only) */ 137#define OMAP_I2C_CON_STP (1 << 1) /* Stop cond (master only) */ 138#define OMAP_I2C_CON_STT (1 << 0) /* Start condition (master) */ 139 140/* I2C SCL time value when Master */ 141#define OMAP_I2C_SCLL_HSSCLL 8 142#define OMAP_I2C_SCLH_HSSCLH 8 143 144/* I2C System Test Register (OMAP_I2C_SYSTEST): */ 145#define OMAP_I2C_SYSTEST_ST_EN (1 << 15) /* System test enable */ 146#define OMAP_I2C_SYSTEST_FREE (1 << 14) /* Free running mode */ 147#define OMAP_I2C_SYSTEST_TMODE_MASK (3 << 12) /* Test mode select */ 148#define OMAP_I2C_SYSTEST_TMODE_SHIFT (12) /* Test mode select */ 149/* Functional mode */ 150#define OMAP_I2C_SYSTEST_SCL_I_FUNC (1 << 8) /* SCL line input value */ 151#define OMAP_I2C_SYSTEST_SCL_O_FUNC (1 << 7) /* SCL line output value */ 152#define OMAP_I2C_SYSTEST_SDA_I_FUNC (1 << 6) /* SDA line input value */ 153#define OMAP_I2C_SYSTEST_SDA_O_FUNC (1 << 5) /* SDA line output value */ 154/* SDA/SCL IO mode */ 155#define OMAP_I2C_SYSTEST_SCL_I (1 << 3) /* SCL line sense in */ 156#define OMAP_I2C_SYSTEST_SCL_O (1 << 2) /* SCL line drive out */ 157#define OMAP_I2C_SYSTEST_SDA_I (1 << 1) /* SDA line sense in */ 158#define OMAP_I2C_SYSTEST_SDA_O (1 << 0) /* SDA line drive out */ 159 160/* OCP_SYSSTATUS bit definitions */ 161#define SYSS_RESETDONE_MASK (1 << 0) 162 163/* OCP_SYSCONFIG bit definitions */ 164#define SYSC_CLOCKACTIVITY_MASK (0x3 << 8) 165#define SYSC_SIDLEMODE_MASK (0x3 << 3) 166#define SYSC_ENAWAKEUP_MASK (1 << 2) 167#define SYSC_SOFTRESET_MASK (1 << 1) 168#define SYSC_AUTOIDLE_MASK (1 << 0) 169 170#define SYSC_IDLEMODE_SMART 0x2 171#define SYSC_CLOCKACTIVITY_FCLK 0x2 172 173/* Errata definitions */ 174#define I2C_OMAP_ERRATA_I207 (1 << 0) 175#define I2C_OMAP_ERRATA_I462 (1 << 1) 176 177#define OMAP_I2C_IP_V2_INTERRUPTS_MASK 0x6FFF 178 179struct omap_i2c_dev { 180 struct device *dev; 181 void __iomem *base; /* virtual */ 182 int irq; 183 int reg_shift; /* bit shift for I2C register addresses */ 184 struct completion cmd_complete; 185 struct resource *ioarea; 186 u32 latency; /* maximum mpu wkup latency */ 187 void (*set_mpu_wkup_lat)(struct device *dev, 188 long latency); 189 u32 speed; /* Speed of bus in kHz */ 190 u32 flags; 191 u16 scheme; 192 u16 cmd_err; 193 u8 *buf; 194 u8 *regs; 195 size_t buf_len; 196 struct i2c_adapter adapter; 197 u8 threshold; 198 u8 fifo_size; /* use as flag and value 199 * fifo_size==0 implies no fifo 200 * if set, should be trsh+1 201 */ 202 u32 rev; 203 unsigned b_hw:1; /* bad h/w fixes */ 204 unsigned bb_valid:1; /* true when BB-bit reflects 205 * the I2C bus state 206 */ 207 unsigned receiver:1; /* true when we're in receiver mode */ 208 u16 iestate; /* Saved interrupt register */ 209 u16 pscstate; 210 u16 scllstate; 211 u16 sclhstate; 212 u16 syscstate; 213 u16 westate; 214 u16 errata; 215 struct mux_state *mux_state; 216}; 217 218static const u8 reg_map_ip_v1[] = { 219 [OMAP_I2C_REV_REG] = 0x00, 220 [OMAP_I2C_IE_REG] = 0x01, 221 [OMAP_I2C_STAT_REG] = 0x02, 222 [OMAP_I2C_IV_REG] = 0x03, 223 [OMAP_I2C_WE_REG] = 0x03, 224 [OMAP_I2C_SYSS_REG] = 0x04, 225 [OMAP_I2C_BUF_REG] = 0x05, 226 [OMAP_I2C_CNT_REG] = 0x06, 227 [OMAP_I2C_DATA_REG] = 0x07, 228 [OMAP_I2C_SYSC_REG] = 0x08, 229 [OMAP_I2C_CON_REG] = 0x09, 230 [OMAP_I2C_OA_REG] = 0x0a, 231 [OMAP_I2C_SA_REG] = 0x0b, 232 [OMAP_I2C_PSC_REG] = 0x0c, 233 [OMAP_I2C_SCLL_REG] = 0x0d, 234 [OMAP_I2C_SCLH_REG] = 0x0e, 235 [OMAP_I2C_SYSTEST_REG] = 0x0f, 236 [OMAP_I2C_BUFSTAT_REG] = 0x10, 237}; 238 239static const u8 reg_map_ip_v2[] = { 240 [OMAP_I2C_REV_REG] = 0x04, 241 [OMAP_I2C_IE_REG] = 0x2c, 242 [OMAP_I2C_STAT_REG] = 0x28, 243 [OMAP_I2C_IV_REG] = 0x34, 244 [OMAP_I2C_WE_REG] = 0x34, 245 [OMAP_I2C_SYSS_REG] = 0x90, 246 [OMAP_I2C_BUF_REG] = 0x94, 247 [OMAP_I2C_CNT_REG] = 0x98, 248 [OMAP_I2C_DATA_REG] = 0x9c, 249 [OMAP_I2C_SYSC_REG] = 0x10, 250 [OMAP_I2C_CON_REG] = 0xa4, 251 [OMAP_I2C_OA_REG] = 0xa8, 252 [OMAP_I2C_SA_REG] = 0xac, 253 [OMAP_I2C_PSC_REG] = 0xb0, 254 [OMAP_I2C_SCLL_REG] = 0xb4, 255 [OMAP_I2C_SCLH_REG] = 0xb8, 256 [OMAP_I2C_SYSTEST_REG] = 0xbC, 257 [OMAP_I2C_BUFSTAT_REG] = 0xc0, 258 [OMAP_I2C_IP_V2_REVNB_LO] = 0x00, 259 [OMAP_I2C_IP_V2_REVNB_HI] = 0x04, 260 [OMAP_I2C_IP_V2_IRQSTATUS_RAW] = 0x24, 261 [OMAP_I2C_IP_V2_IRQENABLE_SET] = 0x2c, 262 [OMAP_I2C_IP_V2_IRQENABLE_CLR] = 0x30, 263}; 264 265static int omap_i2c_xfer_data(struct omap_i2c_dev *omap); 266 267static inline void omap_i2c_write_reg(struct omap_i2c_dev *omap, 268 int reg, u16 val) 269{ 270 writew_relaxed(val, omap->base + 271 (omap->regs[reg] << omap->reg_shift)); 272} 273 274static inline u16 omap_i2c_read_reg(struct omap_i2c_dev *omap, int reg) 275{ 276 return readw_relaxed(omap->base + 277 (omap->regs[reg] << omap->reg_shift)); 278} 279 280static void __omap_i2c_init(struct omap_i2c_dev *omap) 281{ 282 283 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0); 284 285 /* Setup clock prescaler to obtain approx 12MHz I2C module clock: */ 286 omap_i2c_write_reg(omap, OMAP_I2C_PSC_REG, omap->pscstate); 287 288 /* SCL low and high time values */ 289 omap_i2c_write_reg(omap, OMAP_I2C_SCLL_REG, omap->scllstate); 290 omap_i2c_write_reg(omap, OMAP_I2C_SCLH_REG, omap->sclhstate); 291 if (omap->rev >= OMAP_I2C_REV_ON_3430_3530) 292 omap_i2c_write_reg(omap, OMAP_I2C_WE_REG, omap->westate); 293 294 /* Take the I2C module out of reset: */ 295 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); 296 297 /* 298 * NOTE: right after setting CON_EN, STAT_BB could be 0 while the 299 * bus is busy. It will be changed to 1 on the next IP FCLK clock. 300 * udelay(1) will be enough to fix that. 301 */ 302 303 /* 304 * Don't write to this register if the IE state is 0 as it can 305 * cause deadlock. 306 */ 307 if (omap->iestate) 308 omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, omap->iestate); 309} 310 311static int omap_i2c_reset(struct omap_i2c_dev *omap) 312{ 313 unsigned long timeout; 314 u16 sysc; 315 316 if (omap->rev >= OMAP_I2C_OMAP1_REV_2) { 317 sysc = omap_i2c_read_reg(omap, OMAP_I2C_SYSC_REG); 318 319 /* Disable I2C controller before soft reset */ 320 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 321 omap_i2c_read_reg(omap, OMAP_I2C_CON_REG) & 322 ~(OMAP_I2C_CON_EN)); 323 324 omap_i2c_write_reg(omap, OMAP_I2C_SYSC_REG, SYSC_SOFTRESET_MASK); 325 /* For some reason we need to set the EN bit before the 326 * reset done bit gets set. */ 327 timeout = jiffies + OMAP_I2C_TIMEOUT; 328 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_EN); 329 while (!(omap_i2c_read_reg(omap, OMAP_I2C_SYSS_REG) & 330 SYSS_RESETDONE_MASK)) { 331 if (time_after(jiffies, timeout)) { 332 dev_warn(omap->dev, "timeout waiting " 333 "for controller reset\n"); 334 return -ETIMEDOUT; 335 } 336 msleep(1); 337 } 338 339 /* SYSC register is cleared by the reset; rewrite it */ 340 omap_i2c_write_reg(omap, OMAP_I2C_SYSC_REG, sysc); 341 342 if (omap->rev > OMAP_I2C_REV_ON_3430_3530) { 343 /* Schedule I2C-bus monitoring on the next transfer */ 344 omap->bb_valid = 0; 345 } 346 } 347 348 return 0; 349} 350 351static int omap_i2c_init(struct omap_i2c_dev *omap) 352{ 353 u16 psc = 0, scll = 0, sclh = 0; 354 u16 fsscll = 0, fssclh = 0, hsscll = 0, hssclh = 0; 355 unsigned long fclk_rate = 12000000; 356 unsigned long internal_clk = 0; 357 struct clk *fclk; 358 int error; 359 360 if (omap->rev >= OMAP_I2C_REV_ON_3430_3530) { 361 /* 362 * Enabling all wakup sources to stop I2C freezing on 363 * WFI instruction. 364 * REVISIT: Some wkup sources might not be needed. 365 */ 366 omap->westate = OMAP_I2C_WE_ALL; 367 } 368 369 if (omap->flags & OMAP_I2C_FLAG_ALWAYS_ARMXOR_CLK) { 370 /* 371 * The I2C functional clock is the armxor_ck, so there's 372 * no need to get "armxor_ck" separately. Now, if OMAP2420 373 * always returns 12MHz for the functional clock, we can 374 * do this bit unconditionally. 375 */ 376 fclk = clk_get(omap->dev, "fck"); 377 if (IS_ERR(fclk)) { 378 error = PTR_ERR(fclk); 379 dev_err(omap->dev, "could not get fck: %i\n", error); 380 381 return error; 382 } 383 384 fclk_rate = clk_get_rate(fclk); 385 clk_put(fclk); 386 387 /* TRM for 5912 says the I2C clock must be prescaled to be 388 * between 7 - 12 MHz. The XOR input clock is typically 389 * 12, 13 or 19.2 MHz. So we should have code that produces: 390 * 391 * XOR MHz Divider Prescaler 392 * 12 1 0 393 * 13 2 1 394 * 19.2 2 1 395 */ 396 if (fclk_rate > 12000000) 397 psc = fclk_rate / 12000000; 398 } 399 400 if (!(omap->flags & OMAP_I2C_FLAG_SIMPLE_CLOCK)) { 401 402 /* 403 * HSI2C controller internal clk rate should be 19.2 Mhz for 404 * HS and for all modes on 2430. On 34xx we can use lower rate 405 * to get longer filter period for better noise suppression. 406 * The filter is iclk (fclk for HS) period. 407 */ 408 if (omap->speed > 400 || 409 omap->flags & OMAP_I2C_FLAG_FORCE_19200_INT_CLK) 410 internal_clk = 19200; 411 else if (omap->speed > 100) 412 internal_clk = 9600; 413 else 414 internal_clk = 4000; 415 fclk = clk_get(omap->dev, "fck"); 416 if (IS_ERR(fclk)) { 417 error = PTR_ERR(fclk); 418 dev_err(omap->dev, "could not get fck: %i\n", error); 419 420 return error; 421 } 422 fclk_rate = clk_get_rate(fclk) / 1000; 423 clk_put(fclk); 424 425 /* Compute prescaler divisor */ 426 psc = fclk_rate / internal_clk; 427 psc = psc - 1; 428 429 /* If configured for High Speed */ 430 if (omap->speed > 400) { 431 unsigned long scl; 432 433 /* For first phase of HS mode */ 434 scl = internal_clk / 400; 435 fsscll = scl - (scl / 3) - 7; 436 fssclh = (scl / 3) - 5; 437 438 /* For second phase of HS mode */ 439 scl = fclk_rate / omap->speed; 440 hsscll = scl - (scl / 3) - 7; 441 hssclh = (scl / 3) - 5; 442 } else if (omap->speed > 100) { 443 unsigned long scl; 444 445 /* Fast mode */ 446 scl = internal_clk / omap->speed; 447 fsscll = scl - (scl / 3) - 7; 448 fssclh = (scl / 3) - 5; 449 } else { 450 /* Standard mode */ 451 fsscll = internal_clk / (omap->speed * 2) - 7; 452 fssclh = internal_clk / (omap->speed * 2) - 5; 453 } 454 scll = (hsscll << OMAP_I2C_SCLL_HSSCLL) | fsscll; 455 sclh = (hssclh << OMAP_I2C_SCLH_HSSCLH) | fssclh; 456 } else { 457 /* Program desired operating rate */ 458 fclk_rate /= (psc + 1) * 1000; 459 if (psc > 2) 460 psc = 2; 461 scll = fclk_rate / (omap->speed * 2) - 7 + psc; 462 sclh = fclk_rate / (omap->speed * 2) - 7 + psc; 463 } 464 465 omap->iestate = (OMAP_I2C_IE_XRDY | OMAP_I2C_IE_RRDY | 466 OMAP_I2C_IE_ARDY | OMAP_I2C_IE_NACK | 467 OMAP_I2C_IE_AL) | ((omap->fifo_size) ? 468 (OMAP_I2C_IE_RDR | OMAP_I2C_IE_XDR) : 0); 469 470 omap->pscstate = psc; 471 omap->scllstate = scll; 472 omap->sclhstate = sclh; 473 474 if (omap->rev <= OMAP_I2C_REV_ON_3430_3530) { 475 /* Not implemented */ 476 omap->bb_valid = 1; 477 } 478 479 __omap_i2c_init(omap); 480 481 return 0; 482} 483 484/* 485 * Try bus recovery, but only if SDA is actually low. 486 */ 487static int omap_i2c_recover_bus(struct omap_i2c_dev *omap) 488{ 489 u16 systest; 490 491 systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG); 492 if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) && 493 (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC)) 494 return 0; /* bus seems to already be fine */ 495 if (!(systest & OMAP_I2C_SYSTEST_SCL_I_FUNC)) 496 return -EBUSY; /* recovery would not fix SCL */ 497 return i2c_recover_bus(&omap->adapter); 498} 499 500/* 501 * Waiting on Bus Busy 502 */ 503static int omap_i2c_wait_for_bb(struct omap_i2c_dev *omap) 504{ 505 unsigned long timeout; 506 507 timeout = jiffies + OMAP_I2C_TIMEOUT; 508 while (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG) & OMAP_I2C_STAT_BB) { 509 if (time_after(jiffies, timeout)) 510 return omap_i2c_recover_bus(omap); 511 msleep(1); 512 } 513 514 return 0; 515} 516 517/* 518 * Wait while BB-bit doesn't reflect the I2C bus state 519 * 520 * In a multimaster environment, after IP software reset, BB-bit value doesn't 521 * correspond to the current bus state. It may happen what BB-bit will be 0, 522 * while the bus is busy due to another I2C master activity. 523 * Here are BB-bit values after reset: 524 * SDA SCL BB NOTES 525 * 0 0 0 1, 2 526 * 1 0 0 1, 2 527 * 0 1 1 528 * 1 1 0 3 529 * Later, if IP detect SDA=0 and SCL=1 (ACK) or SDA 1->0 while SCL=1 (START) 530 * combinations on the bus, it set BB-bit to 1. 531 * If IP detect SDA 0->1 while SCL=1 (STOP) combination on the bus, 532 * it set BB-bit to 0 and BF to 1. 533 * BB and BF bits correctly tracks the bus state while IP is suspended 534 * BB bit became valid on the next FCLK clock after CON_EN bit set 535 * 536 * NOTES: 537 * 1. Any transfer started when BB=0 and bus is busy wouldn't be 538 * completed by IP and results in controller timeout. 539 * 2. Any transfer started when BB=0 and SCL=0 results in IP 540 * starting to drive SDA low. In that case IP corrupt data 541 * on the bus. 542 * 3. Any transfer started in the middle of another master's transfer 543 * results in unpredictable results and data corruption 544 */ 545static int omap_i2c_wait_for_bb_valid(struct omap_i2c_dev *omap) 546{ 547 unsigned long bus_free_timeout = 0; 548 unsigned long timeout; 549 int bus_free = 0; 550 u16 stat, systest; 551 552 if (omap->bb_valid) 553 return 0; 554 555 timeout = jiffies + OMAP_I2C_TIMEOUT; 556 while (1) { 557 stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); 558 /* 559 * We will see BB or BF event in a case IP had detected any 560 * activity on the I2C bus. Now IP correctly tracks the bus 561 * state. BB-bit value is valid. 562 */ 563 if (stat & (OMAP_I2C_STAT_BB | OMAP_I2C_STAT_BF)) 564 break; 565 566 /* 567 * Otherwise, we must look signals on the bus to make 568 * the right decision. 569 */ 570 systest = omap_i2c_read_reg(omap, OMAP_I2C_SYSTEST_REG); 571 if ((systest & OMAP_I2C_SYSTEST_SCL_I_FUNC) && 572 (systest & OMAP_I2C_SYSTEST_SDA_I_FUNC)) { 573 if (!bus_free) { 574 bus_free_timeout = jiffies + 575 OMAP_I2C_BUS_FREE_TIMEOUT; 576 bus_free = 1; 577 } 578 579 /* 580 * SDA and SCL lines was high for 10 ms without bus 581 * activity detected. The bus is free. Consider 582 * BB-bit value is valid. 583 */ 584 if (time_after(jiffies, bus_free_timeout)) 585 break; 586 } else { 587 bus_free = 0; 588 } 589 590 if (time_after(jiffies, timeout)) { 591 /* 592 * SDA or SCL were low for the entire timeout without 593 * any activity detected. Most likely, a slave is 594 * locking up the bus with no master driving the clock. 595 */ 596 dev_warn(omap->dev, "timeout waiting for bus ready\n"); 597 return omap_i2c_recover_bus(omap); 598 } 599 600 msleep(1); 601 } 602 603 omap->bb_valid = 1; 604 return 0; 605} 606 607static void omap_i2c_resize_fifo(struct omap_i2c_dev *omap, u8 size, bool is_rx) 608{ 609 u16 buf; 610 611 if (omap->flags & OMAP_I2C_FLAG_NO_FIFO) 612 return; 613 614 /* 615 * Set up notification threshold based on message size. We're doing 616 * this to try and avoid draining feature as much as possible. Whenever 617 * we have big messages to transfer (bigger than our total fifo size) 618 * then we might use draining feature to transfer the remaining bytes. 619 */ 620 621 omap->threshold = clamp(size, (u8) 1, omap->fifo_size); 622 623 buf = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG); 624 625 if (is_rx) { 626 /* Clear RX Threshold */ 627 buf &= ~(0x3f << 8); 628 buf |= ((omap->threshold - 1) << 8) | OMAP_I2C_BUF_RXFIF_CLR; 629 } else { 630 /* Clear TX Threshold */ 631 buf &= ~0x3f; 632 buf |= (omap->threshold - 1) | OMAP_I2C_BUF_TXFIF_CLR; 633 } 634 635 omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, buf); 636 637 if (omap->rev < OMAP_I2C_REV_ON_3630) 638 omap->b_hw = 1; /* Enable hardware fixes */ 639 640 /* calculate wakeup latency constraint for MPU */ 641 if (omap->set_mpu_wkup_lat != NULL) 642 omap->latency = (1000000 * omap->threshold) / 643 (1000 * omap->speed / 8); 644} 645 646static void omap_i2c_wait(struct omap_i2c_dev *omap) 647{ 648 u16 stat; 649 u16 mask = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG); 650 int count = 0; 651 652 do { 653 stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); 654 count++; 655 } while (!(stat & mask) && count < 5); 656} 657 658/* 659 * Low level master read/write transaction. 660 */ 661static int omap_i2c_xfer_msg(struct i2c_adapter *adap, 662 struct i2c_msg *msg, int stop, bool polling) 663{ 664 struct omap_i2c_dev *omap = i2c_get_adapdata(adap); 665 unsigned long time_left; 666 u16 w; 667 int ret; 668 669 dev_dbg(omap->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n", 670 msg->addr, msg->len, msg->flags, stop); 671 672 omap->receiver = !!(msg->flags & I2C_M_RD); 673 omap_i2c_resize_fifo(omap, msg->len, omap->receiver); 674 675 omap_i2c_write_reg(omap, OMAP_I2C_SA_REG, msg->addr); 676 677 /* REVISIT: Could the STB bit of I2C_CON be used with probing? */ 678 omap->buf = msg->buf; 679 omap->buf_len = msg->len; 680 681 /* make sure writes to omap->buf_len are ordered */ 682 barrier(); 683 684 omap_i2c_write_reg(omap, OMAP_I2C_CNT_REG, omap->buf_len); 685 686 /* Clear the FIFO Buffers */ 687 w = omap_i2c_read_reg(omap, OMAP_I2C_BUF_REG); 688 w |= OMAP_I2C_BUF_RXFIF_CLR | OMAP_I2C_BUF_TXFIF_CLR; 689 omap_i2c_write_reg(omap, OMAP_I2C_BUF_REG, w); 690 691 if (!polling) 692 reinit_completion(&omap->cmd_complete); 693 omap->cmd_err = 0; 694 695 w = OMAP_I2C_CON_EN | OMAP_I2C_CON_MST | OMAP_I2C_CON_STT; 696 697 /* High speed configuration */ 698 if (omap->speed > 400) 699 w |= OMAP_I2C_CON_OPMODE_HS; 700 701 if (msg->flags & I2C_M_STOP) 702 stop = 1; 703 if (msg->flags & I2C_M_TEN) 704 w |= OMAP_I2C_CON_XA; 705 if (!(msg->flags & I2C_M_RD)) 706 w |= OMAP_I2C_CON_TRX; 707 708 if (!omap->b_hw && stop) 709 w |= OMAP_I2C_CON_STP; 710 /* 711 * NOTE: STAT_BB bit could became 1 here if another master occupy 712 * the bus. IP successfully complete transfer when the bus will be 713 * free again (BB reset to 0). 714 */ 715 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w); 716 717 /* 718 * Don't write stt and stp together on some hardware. 719 */ 720 if (omap->b_hw && stop) { 721 unsigned long delay = jiffies + OMAP_I2C_TIMEOUT; 722 u16 con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG); 723 while (con & OMAP_I2C_CON_STT) { 724 con = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG); 725 726 /* Let the user know if i2c is in a bad state */ 727 if (time_after(jiffies, delay)) { 728 dev_err(omap->dev, "controller timed out " 729 "waiting for start condition to finish\n"); 730 return -ETIMEDOUT; 731 } 732 cpu_relax(); 733 } 734 735 w |= OMAP_I2C_CON_STP; 736 w &= ~OMAP_I2C_CON_STT; 737 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w); 738 } 739 740 /* 741 * REVISIT: We should abort the transfer on signals, but the bus goes 742 * into arbitration and we're currently unable to recover from it. 743 */ 744 if (!polling) { 745 time_left = wait_for_completion_timeout(&omap->cmd_complete, 746 OMAP_I2C_TIMEOUT); 747 } else { 748 do { 749 omap_i2c_wait(omap); 750 ret = omap_i2c_xfer_data(omap); 751 } while (ret == -EAGAIN); 752 753 time_left = !ret; 754 } 755 756 if (time_left == 0) { 757 omap_i2c_reset(omap); 758 __omap_i2c_init(omap); 759 return -ETIMEDOUT; 760 } 761 762 if (likely(!omap->cmd_err)) 763 return 0; 764 765 /* We have an error */ 766 if (omap->cmd_err & (OMAP_I2C_STAT_ROVR | OMAP_I2C_STAT_XUDF)) { 767 omap_i2c_reset(omap); 768 __omap_i2c_init(omap); 769 return -EIO; 770 } 771 772 if (omap->cmd_err & OMAP_I2C_STAT_AL) 773 return -EAGAIN; 774 775 if (omap->cmd_err & OMAP_I2C_STAT_NACK) { 776 if (msg->flags & I2C_M_IGNORE_NAK) 777 return 0; 778 779 w = omap_i2c_read_reg(omap, OMAP_I2C_CON_REG); 780 w |= OMAP_I2C_CON_STP; 781 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, w); 782 return -EREMOTEIO; 783 } 784 return -EIO; 785} 786 787 788/* 789 * Prepare controller for a transaction and call omap_i2c_xfer_msg 790 * to do the work during IRQ processing. 791 */ 792static int 793omap_i2c_xfer_common(struct i2c_adapter *adap, struct i2c_msg msgs[], int num, 794 bool polling) 795{ 796 struct omap_i2c_dev *omap = i2c_get_adapdata(adap); 797 int i; 798 int r; 799 800 r = pm_runtime_get_sync(omap->dev); 801 if (r < 0) 802 goto out; 803 804 r = omap_i2c_wait_for_bb_valid(omap); 805 if (r < 0) 806 goto out; 807 808 r = omap_i2c_wait_for_bb(omap); 809 if (r < 0) 810 goto out; 811 812 if (omap->set_mpu_wkup_lat != NULL) 813 omap->set_mpu_wkup_lat(omap->dev, omap->latency); 814 815 for (i = 0; i < num; i++) { 816 r = omap_i2c_xfer_msg(adap, &msgs[i], (i == (num - 1)), 817 polling); 818 if (r != 0) 819 break; 820 } 821 822 if (r == 0) 823 r = num; 824 825 omap_i2c_wait_for_bb(omap); 826 827 if (omap->set_mpu_wkup_lat != NULL) 828 omap->set_mpu_wkup_lat(omap->dev, -1); 829 830out: 831 pm_runtime_put_autosuspend(omap->dev); 832 return r; 833} 834 835static int 836omap_i2c_xfer_irq(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 837{ 838 return omap_i2c_xfer_common(adap, msgs, num, false); 839} 840 841static int 842omap_i2c_xfer_polling(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) 843{ 844 return omap_i2c_xfer_common(adap, msgs, num, true); 845} 846 847static u32 848omap_i2c_func(struct i2c_adapter *adap) 849{ 850 return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK) | 851 I2C_FUNC_PROTOCOL_MANGLING; 852} 853 854static inline void 855omap_i2c_complete_cmd(struct omap_i2c_dev *omap, u16 err) 856{ 857 omap->cmd_err |= err; 858 complete(&omap->cmd_complete); 859} 860 861static inline void 862omap_i2c_ack_stat(struct omap_i2c_dev *omap, u16 stat) 863{ 864 omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, stat); 865} 866 867static inline void i2c_omap_errata_i207(struct omap_i2c_dev *omap, u16 stat) 868{ 869 /* 870 * I2C Errata(Errata Nos. OMAP2: 1.67, OMAP3: 1.8) 871 * Not applicable for OMAP4. 872 * Under certain rare conditions, RDR could be set again 873 * when the bus is busy, then ignore the interrupt and 874 * clear the interrupt. 875 */ 876 if (stat & OMAP_I2C_STAT_RDR) { 877 /* Step 1: If RDR is set, clear it */ 878 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR); 879 880 /* Step 2: */ 881 if (!(omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG) 882 & OMAP_I2C_STAT_BB)) { 883 884 /* Step 3: */ 885 if (omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG) 886 & OMAP_I2C_STAT_RDR) { 887 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR); 888 dev_dbg(omap->dev, "RDR when bus is busy.\n"); 889 } 890 891 } 892 } 893} 894 895/* rev1 devices are apparently only on some 15xx */ 896#ifdef CONFIG_ARCH_OMAP15XX 897 898static irqreturn_t 899omap_i2c_omap1_isr(int this_irq, void *dev_id) 900{ 901 struct omap_i2c_dev *omap = dev_id; 902 u16 iv, w; 903 904 if (pm_runtime_suspended(omap->dev)) 905 return IRQ_NONE; 906 907 iv = omap_i2c_read_reg(omap, OMAP_I2C_IV_REG); 908 switch (iv) { 909 case 0x00: /* None */ 910 break; 911 case 0x01: /* Arbitration lost */ 912 dev_err(omap->dev, "Arbitration lost\n"); 913 omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_AL); 914 break; 915 case 0x02: /* No acknowledgement */ 916 omap_i2c_complete_cmd(omap, OMAP_I2C_STAT_NACK); 917 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, OMAP_I2C_CON_STP); 918 break; 919 case 0x03: /* Register access ready */ 920 omap_i2c_complete_cmd(omap, 0); 921 break; 922 case 0x04: /* Receive data ready */ 923 if (omap->buf_len) { 924 w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG); 925 *omap->buf++ = w; 926 omap->buf_len--; 927 if (omap->buf_len) { 928 *omap->buf++ = w >> 8; 929 omap->buf_len--; 930 } 931 } else 932 dev_err(omap->dev, "RRDY IRQ while no data requested\n"); 933 break; 934 case 0x05: /* Transmit data ready */ 935 if (omap->buf_len) { 936 w = *omap->buf++; 937 omap->buf_len--; 938 if (omap->buf_len) { 939 w |= *omap->buf++ << 8; 940 omap->buf_len--; 941 } 942 omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w); 943 } else 944 dev_err(omap->dev, "XRDY IRQ while no data to send\n"); 945 break; 946 default: 947 return IRQ_NONE; 948 } 949 950 return IRQ_HANDLED; 951} 952#else 953#define omap_i2c_omap1_isr NULL 954#endif 955 956/* 957 * OMAP3430 Errata i462: When an XRDY/XDR is hit, wait for XUDF before writing 958 * data to DATA_REG. Otherwise some data bytes can be lost while transferring 959 * them from the memory to the I2C interface. 960 */ 961static int errata_omap3_i462(struct omap_i2c_dev *omap) 962{ 963 unsigned long timeout = 10000; 964 u16 stat; 965 966 do { 967 stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); 968 if (stat & OMAP_I2C_STAT_XUDF) 969 break; 970 971 if (stat & (OMAP_I2C_STAT_NACK | OMAP_I2C_STAT_AL)) { 972 omap_i2c_ack_stat(omap, (OMAP_I2C_STAT_XRDY | 973 OMAP_I2C_STAT_XDR)); 974 if (stat & OMAP_I2C_STAT_NACK) { 975 omap->cmd_err |= OMAP_I2C_STAT_NACK; 976 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK); 977 } 978 979 if (stat & OMAP_I2C_STAT_AL) { 980 dev_err(omap->dev, "Arbitration lost\n"); 981 omap->cmd_err |= OMAP_I2C_STAT_AL; 982 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL); 983 } 984 985 return -EIO; 986 } 987 988 cpu_relax(); 989 } while (--timeout); 990 991 if (!timeout) { 992 dev_err(omap->dev, "timeout waiting on XUDF bit\n"); 993 return 0; 994 } 995 996 return 0; 997} 998 999static void omap_i2c_receive_data(struct omap_i2c_dev *omap, u8 num_bytes, 1000 bool is_rdr) 1001{ 1002 u16 w; 1003 1004 while (num_bytes--) { 1005 w = omap_i2c_read_reg(omap, OMAP_I2C_DATA_REG); 1006 *omap->buf++ = w; 1007 omap->buf_len--; 1008 1009 /* 1010 * Data reg in 2430, omap3 and 1011 * omap4 is 8 bit wide 1012 */ 1013 if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) { 1014 *omap->buf++ = w >> 8; 1015 omap->buf_len--; 1016 } 1017 } 1018} 1019 1020static int omap_i2c_transmit_data(struct omap_i2c_dev *omap, u8 num_bytes, 1021 bool is_xdr) 1022{ 1023 u16 w; 1024 1025 while (num_bytes--) { 1026 w = *omap->buf++; 1027 omap->buf_len--; 1028 1029 /* 1030 * Data reg in 2430, omap3 and 1031 * omap4 is 8 bit wide 1032 */ 1033 if (omap->flags & OMAP_I2C_FLAG_16BIT_DATA_REG) { 1034 w |= *omap->buf++ << 8; 1035 omap->buf_len--; 1036 } 1037 1038 if (omap->errata & I2C_OMAP_ERRATA_I462) { 1039 int ret; 1040 1041 ret = errata_omap3_i462(omap); 1042 if (ret < 0) 1043 return ret; 1044 } 1045 1046 omap_i2c_write_reg(omap, OMAP_I2C_DATA_REG, w); 1047 } 1048 1049 return 0; 1050} 1051 1052static int omap_i2c_xfer_data(struct omap_i2c_dev *omap) 1053{ 1054 u16 bits; 1055 u16 stat; 1056 int err = 0, count = 0; 1057 1058 do { 1059 bits = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG); 1060 stat = omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); 1061 stat &= bits; 1062 1063 /* If we're in receiver mode, ignore XDR/XRDY */ 1064 if (omap->receiver) 1065 stat &= ~(OMAP_I2C_STAT_XDR | OMAP_I2C_STAT_XRDY); 1066 else 1067 stat &= ~(OMAP_I2C_STAT_RDR | OMAP_I2C_STAT_RRDY); 1068 1069 if (!stat) { 1070 /* my work here is done */ 1071 err = -EAGAIN; 1072 break; 1073 } 1074 1075 dev_dbg(omap->dev, "IRQ (ISR = 0x%04x)\n", stat); 1076 if (count++ == 100) { 1077 dev_warn(omap->dev, "Too much work in one IRQ\n"); 1078 break; 1079 } 1080 1081 if (stat & OMAP_I2C_STAT_NACK) { 1082 omap->cmd_err |= OMAP_I2C_STAT_NACK; 1083 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_NACK); 1084 1085 if (!(stat & ~OMAP_I2C_STAT_NACK)) { 1086 err = -EAGAIN; 1087 break; 1088 } 1089 } 1090 1091 if (stat & OMAP_I2C_STAT_AL) { 1092 dev_err(omap->dev, "Arbitration lost\n"); 1093 err |= OMAP_I2C_STAT_AL; 1094 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_AL); 1095 } 1096 1097 /* 1098 * ProDB0017052: Clear ARDY bit twice 1099 */ 1100 if (stat & OMAP_I2C_STAT_ARDY) 1101 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ARDY); 1102 1103 if (stat & (OMAP_I2C_STAT_ARDY | OMAP_I2C_STAT_NACK | 1104 OMAP_I2C_STAT_AL)) { 1105 omap_i2c_ack_stat(omap, (OMAP_I2C_STAT_RRDY | 1106 OMAP_I2C_STAT_RDR | 1107 OMAP_I2C_STAT_XRDY | 1108 OMAP_I2C_STAT_XDR | 1109 OMAP_I2C_STAT_ARDY)); 1110 break; 1111 } 1112 1113 if (stat & OMAP_I2C_STAT_RDR) { 1114 u8 num_bytes = 1; 1115 1116 if (omap->fifo_size) 1117 num_bytes = omap->buf_len; 1118 1119 if (omap->errata & I2C_OMAP_ERRATA_I207) { 1120 i2c_omap_errata_i207(omap, stat); 1121 num_bytes = (omap_i2c_read_reg(omap, 1122 OMAP_I2C_BUFSTAT_REG) >> 8) & 0x3F; 1123 } 1124 1125 omap_i2c_receive_data(omap, num_bytes, true); 1126 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RDR); 1127 continue; 1128 } 1129 1130 if (stat & OMAP_I2C_STAT_RRDY) { 1131 u8 num_bytes = 1; 1132 1133 if (omap->threshold) 1134 num_bytes = omap->threshold; 1135 1136 omap_i2c_receive_data(omap, num_bytes, false); 1137 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_RRDY); 1138 continue; 1139 } 1140 1141 if (stat & OMAP_I2C_STAT_XDR) { 1142 u8 num_bytes = 1; 1143 int ret; 1144 1145 if (omap->fifo_size) 1146 num_bytes = omap->buf_len; 1147 1148 ret = omap_i2c_transmit_data(omap, num_bytes, true); 1149 if (ret < 0) 1150 break; 1151 1152 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XDR); 1153 continue; 1154 } 1155 1156 if (stat & OMAP_I2C_STAT_XRDY) { 1157 u8 num_bytes = 1; 1158 int ret; 1159 1160 if (omap->threshold) 1161 num_bytes = omap->threshold; 1162 1163 ret = omap_i2c_transmit_data(omap, num_bytes, false); 1164 if (ret < 0) 1165 break; 1166 1167 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XRDY); 1168 continue; 1169 } 1170 1171 if (stat & OMAP_I2C_STAT_ROVR) { 1172 dev_err(omap->dev, "Receive overrun\n"); 1173 err |= OMAP_I2C_STAT_ROVR; 1174 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_ROVR); 1175 break; 1176 } 1177 1178 if (stat & OMAP_I2C_STAT_XUDF) { 1179 dev_err(omap->dev, "Transmit underflow\n"); 1180 err |= OMAP_I2C_STAT_XUDF; 1181 omap_i2c_ack_stat(omap, OMAP_I2C_STAT_XUDF); 1182 break; 1183 } 1184 } while (stat); 1185 1186 return err; 1187} 1188 1189static irqreturn_t 1190omap_i2c_isr_thread(int this_irq, void *dev_id) 1191{ 1192 int ret; 1193 struct omap_i2c_dev *omap = dev_id; 1194 1195 ret = omap_i2c_xfer_data(omap); 1196 if (ret != -EAGAIN) 1197 omap_i2c_complete_cmd(omap, ret); 1198 1199 return IRQ_HANDLED; 1200} 1201 1202static const struct i2c_algorithm omap_i2c_algo = { 1203 .xfer = omap_i2c_xfer_irq, 1204 .xfer_atomic = omap_i2c_xfer_polling, 1205 .functionality = omap_i2c_func, 1206}; 1207 1208static const struct i2c_adapter_quirks omap_i2c_quirks = { 1209 .flags = I2C_AQ_NO_ZERO_LEN, 1210}; 1211 1212#ifdef CONFIG_OF 1213static struct omap_i2c_bus_platform_data omap2420_pdata = { 1214 .rev = OMAP_I2C_IP_VERSION_1, 1215 .flags = OMAP_I2C_FLAG_NO_FIFO | 1216 OMAP_I2C_FLAG_SIMPLE_CLOCK | 1217 OMAP_I2C_FLAG_16BIT_DATA_REG | 1218 OMAP_I2C_FLAG_BUS_SHIFT_2, 1219}; 1220 1221static struct omap_i2c_bus_platform_data omap2430_pdata = { 1222 .rev = OMAP_I2C_IP_VERSION_1, 1223 .flags = OMAP_I2C_FLAG_BUS_SHIFT_2 | 1224 OMAP_I2C_FLAG_FORCE_19200_INT_CLK, 1225}; 1226 1227static struct omap_i2c_bus_platform_data omap3_pdata = { 1228 .rev = OMAP_I2C_IP_VERSION_1, 1229 .flags = OMAP_I2C_FLAG_BUS_SHIFT_2, 1230}; 1231 1232static struct omap_i2c_bus_platform_data omap4_pdata = { 1233 .rev = OMAP_I2C_IP_VERSION_2, 1234}; 1235 1236static const struct of_device_id omap_i2c_of_match[] = { 1237 { 1238 .compatible = "ti,omap4-i2c", 1239 .data = &omap4_pdata, 1240 }, 1241 { 1242 .compatible = "ti,omap3-i2c", 1243 .data = &omap3_pdata, 1244 }, 1245 { 1246 .compatible = "ti,omap2430-i2c", 1247 .data = &omap2430_pdata, 1248 }, 1249 { 1250 .compatible = "ti,omap2420-i2c", 1251 .data = &omap2420_pdata, 1252 }, 1253 { } 1254}; 1255MODULE_DEVICE_TABLE(of, omap_i2c_of_match); 1256#endif 1257 1258#define OMAP_I2C_SCHEME(rev) ((rev & 0xc000) >> 14) 1259 1260#define OMAP_I2C_REV_SCHEME_0_MAJOR(rev) (rev >> 4) 1261#define OMAP_I2C_REV_SCHEME_0_MINOR(rev) (rev & 0xf) 1262 1263#define OMAP_I2C_REV_SCHEME_1_MAJOR(rev) ((rev & 0x0700) >> 7) 1264#define OMAP_I2C_REV_SCHEME_1_MINOR(rev) (rev & 0x1f) 1265#define OMAP_I2C_SCHEME_0 0 1266#define OMAP_I2C_SCHEME_1 1 1267 1268static int omap_i2c_get_scl(struct i2c_adapter *adap) 1269{ 1270 struct omap_i2c_dev *dev = i2c_get_adapdata(adap); 1271 u32 reg; 1272 1273 reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); 1274 1275 return reg & OMAP_I2C_SYSTEST_SCL_I_FUNC; 1276} 1277 1278static int omap_i2c_get_sda(struct i2c_adapter *adap) 1279{ 1280 struct omap_i2c_dev *dev = i2c_get_adapdata(adap); 1281 u32 reg; 1282 1283 reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); 1284 1285 return reg & OMAP_I2C_SYSTEST_SDA_I_FUNC; 1286} 1287 1288static void omap_i2c_set_scl(struct i2c_adapter *adap, int val) 1289{ 1290 struct omap_i2c_dev *dev = i2c_get_adapdata(adap); 1291 u32 reg; 1292 1293 reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); 1294 if (val) 1295 reg |= OMAP_I2C_SYSTEST_SCL_O; 1296 else 1297 reg &= ~OMAP_I2C_SYSTEST_SCL_O; 1298 omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg); 1299} 1300 1301static void omap_i2c_prepare_recovery(struct i2c_adapter *adap) 1302{ 1303 struct omap_i2c_dev *dev = i2c_get_adapdata(adap); 1304 u32 reg; 1305 1306 reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); 1307 /* enable test mode */ 1308 reg |= OMAP_I2C_SYSTEST_ST_EN; 1309 /* select SDA/SCL IO mode */ 1310 reg |= 3 << OMAP_I2C_SYSTEST_TMODE_SHIFT; 1311 /* set SCL to high-impedance state (reset value is 0) */ 1312 reg |= OMAP_I2C_SYSTEST_SCL_O; 1313 /* set SDA to high-impedance state (reset value is 0) */ 1314 reg |= OMAP_I2C_SYSTEST_SDA_O; 1315 omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg); 1316} 1317 1318static void omap_i2c_unprepare_recovery(struct i2c_adapter *adap) 1319{ 1320 struct omap_i2c_dev *dev = i2c_get_adapdata(adap); 1321 u32 reg; 1322 1323 reg = omap_i2c_read_reg(dev, OMAP_I2C_SYSTEST_REG); 1324 /* restore reset values */ 1325 reg &= ~OMAP_I2C_SYSTEST_ST_EN; 1326 reg &= ~OMAP_I2C_SYSTEST_TMODE_MASK; 1327 reg &= ~OMAP_I2C_SYSTEST_SCL_O; 1328 reg &= ~OMAP_I2C_SYSTEST_SDA_O; 1329 omap_i2c_write_reg(dev, OMAP_I2C_SYSTEST_REG, reg); 1330} 1331 1332static struct i2c_bus_recovery_info omap_i2c_bus_recovery_info = { 1333 .get_scl = omap_i2c_get_scl, 1334 .get_sda = omap_i2c_get_sda, 1335 .set_scl = omap_i2c_set_scl, 1336 .prepare_recovery = omap_i2c_prepare_recovery, 1337 .unprepare_recovery = omap_i2c_unprepare_recovery, 1338 .recover_bus = i2c_generic_scl_recovery, 1339}; 1340 1341static int 1342omap_i2c_probe(struct platform_device *pdev) 1343{ 1344 struct omap_i2c_dev *omap; 1345 struct i2c_adapter *adap; 1346 const struct omap_i2c_bus_platform_data *pdata = 1347 dev_get_platdata(&pdev->dev); 1348 struct device_node *node = pdev->dev.of_node; 1349 int irq; 1350 int r; 1351 u32 rev; 1352 u16 minor, major; 1353 1354 irq = platform_get_irq(pdev, 0); 1355 if (irq < 0) 1356 return irq; 1357 1358 omap = devm_kzalloc(&pdev->dev, sizeof(struct omap_i2c_dev), GFP_KERNEL); 1359 if (!omap) 1360 return -ENOMEM; 1361 1362 omap->base = devm_platform_ioremap_resource(pdev, 0); 1363 if (IS_ERR(omap->base)) 1364 return PTR_ERR(omap->base); 1365 1366 if (pdev->dev.of_node) { 1367 u32 freq = I2C_MAX_STANDARD_MODE_FREQ; 1368 1369 pdata = device_get_match_data(&pdev->dev); 1370 omap->flags = pdata->flags; 1371 1372 of_property_read_u32(node, "clock-frequency", &freq); 1373 /* convert DT freq value in Hz into kHz for speed */ 1374 omap->speed = freq / 1000; 1375 } else if (pdata != NULL) { 1376 omap->speed = pdata->clkrate; 1377 omap->flags = pdata->flags; 1378 omap->set_mpu_wkup_lat = pdata->set_mpu_wkup_lat; 1379 } 1380 1381 omap->dev = &pdev->dev; 1382 omap->irq = irq; 1383 1384 platform_set_drvdata(pdev, omap); 1385 init_completion(&omap->cmd_complete); 1386 1387 omap->reg_shift = (omap->flags >> OMAP_I2C_FLAG_BUS_SHIFT__SHIFT) & 3; 1388 1389 pm_runtime_enable(omap->dev); 1390 pm_runtime_set_autosuspend_delay(omap->dev, OMAP_I2C_PM_TIMEOUT); 1391 pm_runtime_use_autosuspend(omap->dev); 1392 1393 r = pm_runtime_resume_and_get(omap->dev); 1394 if (r < 0) 1395 goto err_disable_pm; 1396 1397 /* 1398 * Read the Rev hi bit-[15:14] ie scheme this is 1 indicates ver2. 1399 * On omap1/3/2 Offset 4 is IE Reg the bit [15:14] is 0 at reset. 1400 * Also since the omap_i2c_read_reg uses reg_map_ip_* a 1401 * readw_relaxed is done. 1402 */ 1403 rev = readw_relaxed(omap->base + 0x04); 1404 1405 omap->scheme = OMAP_I2C_SCHEME(rev); 1406 switch (omap->scheme) { 1407 case OMAP_I2C_SCHEME_0: 1408 omap->regs = (u8 *)reg_map_ip_v1; 1409 omap->rev = omap_i2c_read_reg(omap, OMAP_I2C_REV_REG); 1410 minor = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev); 1411 major = OMAP_I2C_REV_SCHEME_0_MAJOR(omap->rev); 1412 break; 1413 case OMAP_I2C_SCHEME_1: 1414 default: 1415 omap->regs = (u8 *)reg_map_ip_v2; 1416 rev = (rev << 16) | 1417 omap_i2c_read_reg(omap, OMAP_I2C_IP_V2_REVNB_LO); 1418 minor = OMAP_I2C_REV_SCHEME_1_MINOR(rev); 1419 major = OMAP_I2C_REV_SCHEME_1_MAJOR(rev); 1420 omap->rev = rev; 1421 } 1422 1423 omap->errata = 0; 1424 1425 if (omap->rev >= OMAP_I2C_REV_ON_2430 && 1426 omap->rev < OMAP_I2C_REV_ON_4430_PLUS) 1427 omap->errata |= I2C_OMAP_ERRATA_I207; 1428 1429 if (omap->rev <= OMAP_I2C_REV_ON_3430_3530) 1430 omap->errata |= I2C_OMAP_ERRATA_I462; 1431 1432 if (!(omap->flags & OMAP_I2C_FLAG_NO_FIFO)) { 1433 u16 s; 1434 1435 /* Set up the fifo size - Get total size */ 1436 s = (omap_i2c_read_reg(omap, OMAP_I2C_BUFSTAT_REG) >> 14) & 0x3; 1437 omap->fifo_size = 0x8 << s; 1438 1439 /* 1440 * Set up notification threshold as half the total available 1441 * size. This is to ensure that we can handle the status on int 1442 * call back latencies. 1443 */ 1444 1445 omap->fifo_size = (omap->fifo_size / 2); 1446 1447 if (omap->rev < OMAP_I2C_REV_ON_3630) 1448 omap->b_hw = 1; /* Enable hardware fixes */ 1449 1450 /* calculate wakeup latency constraint for MPU */ 1451 if (omap->set_mpu_wkup_lat != NULL) 1452 omap->latency = (1000000 * omap->fifo_size) / 1453 (1000 * omap->speed / 8); 1454 } 1455 1456 if (of_property_present(node, "mux-states")) { 1457 struct mux_state *mux_state; 1458 1459 mux_state = devm_mux_state_get(&pdev->dev, NULL); 1460 if (IS_ERR(mux_state)) { 1461 r = PTR_ERR(mux_state); 1462 dev_dbg(&pdev->dev, "failed to get I2C mux: %d\n", r); 1463 goto err_put_pm; 1464 } 1465 omap->mux_state = mux_state; 1466 r = mux_state_select(omap->mux_state); 1467 if (r) { 1468 dev_err(&pdev->dev, "failed to select I2C mux: %d\n", r); 1469 goto err_put_pm; 1470 } 1471 } 1472 1473 /* reset ASAP, clearing any IRQs */ 1474 r = omap_i2c_init(omap); 1475 if (r) 1476 goto err_mux_state_deselect; 1477 1478 if (omap->rev < OMAP_I2C_OMAP1_REV_2) 1479 r = devm_request_irq(&pdev->dev, omap->irq, omap_i2c_omap1_isr, 1480 IRQF_NO_SUSPEND, pdev->name, omap); 1481 else 1482 r = devm_request_threaded_irq(&pdev->dev, omap->irq, 1483 NULL, omap_i2c_isr_thread, 1484 IRQF_NO_SUSPEND | IRQF_ONESHOT, 1485 pdev->name, omap); 1486 1487 if (r) { 1488 dev_err(omap->dev, "failure requesting irq %i\n", omap->irq); 1489 goto err_unuse_clocks; 1490 } 1491 1492 adap = &omap->adapter; 1493 i2c_set_adapdata(adap, omap); 1494 adap->owner = THIS_MODULE; 1495 adap->class = I2C_CLASS_DEPRECATED; 1496 strscpy(adap->name, "OMAP I2C adapter", sizeof(adap->name)); 1497 adap->algo = &omap_i2c_algo; 1498 adap->quirks = &omap_i2c_quirks; 1499 adap->dev.parent = &pdev->dev; 1500 adap->dev.of_node = pdev->dev.of_node; 1501 adap->bus_recovery_info = &omap_i2c_bus_recovery_info; 1502 1503 /* i2c device drivers may be active on return from add_adapter() */ 1504 adap->nr = pdev->id; 1505 r = i2c_add_numbered_adapter(adap); 1506 if (r) 1507 goto err_unuse_clocks; 1508 1509 dev_info(omap->dev, "bus %d rev%d.%d at %d kHz\n", adap->nr, 1510 major, minor, omap->speed); 1511 1512 pm_runtime_put_autosuspend(omap->dev); 1513 1514 return 0; 1515 1516err_unuse_clocks: 1517 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0); 1518err_mux_state_deselect: 1519 if (omap->mux_state) 1520 mux_state_deselect(omap->mux_state); 1521err_put_pm: 1522 pm_runtime_put_sync(omap->dev); 1523err_disable_pm: 1524 pm_runtime_dont_use_autosuspend(omap->dev); 1525 pm_runtime_disable(&pdev->dev); 1526 1527 return r; 1528} 1529 1530static void omap_i2c_remove(struct platform_device *pdev) 1531{ 1532 struct omap_i2c_dev *omap = platform_get_drvdata(pdev); 1533 int ret; 1534 1535 i2c_del_adapter(&omap->adapter); 1536 1537 if (omap->mux_state) 1538 mux_state_deselect(omap->mux_state); 1539 1540 ret = pm_runtime_get_sync(&pdev->dev); 1541 if (ret < 0) 1542 dev_err(omap->dev, "Failed to resume hardware, skip disable\n"); 1543 else 1544 omap_i2c_write_reg(omap, OMAP_I2C_CON_REG, 0); 1545 1546 pm_runtime_dont_use_autosuspend(&pdev->dev); 1547 pm_runtime_put_sync(&pdev->dev); 1548 pm_runtime_disable(&pdev->dev); 1549} 1550 1551static int omap_i2c_runtime_suspend(struct device *dev) 1552{ 1553 struct omap_i2c_dev *omap = dev_get_drvdata(dev); 1554 1555 omap->iestate = omap_i2c_read_reg(omap, OMAP_I2C_IE_REG); 1556 1557 if (omap->scheme == OMAP_I2C_SCHEME_0) 1558 omap_i2c_write_reg(omap, OMAP_I2C_IE_REG, 0); 1559 else 1560 omap_i2c_write_reg(omap, OMAP_I2C_IP_V2_IRQENABLE_CLR, 1561 OMAP_I2C_IP_V2_INTERRUPTS_MASK); 1562 1563 if (omap->rev < OMAP_I2C_OMAP1_REV_2) { 1564 omap_i2c_read_reg(omap, OMAP_I2C_IV_REG); /* Read clears */ 1565 } else { 1566 omap_i2c_write_reg(omap, OMAP_I2C_STAT_REG, omap->iestate); 1567 1568 /* Flush posted write */ 1569 omap_i2c_read_reg(omap, OMAP_I2C_STAT_REG); 1570 } 1571 1572 pinctrl_pm_select_sleep_state(dev); 1573 1574 return 0; 1575} 1576 1577static int omap_i2c_runtime_resume(struct device *dev) 1578{ 1579 struct omap_i2c_dev *omap = dev_get_drvdata(dev); 1580 1581 pinctrl_pm_select_default_state(dev); 1582 1583 if (!omap->regs) 1584 return 0; 1585 1586 __omap_i2c_init(omap); 1587 1588 return 0; 1589} 1590 1591static int omap_i2c_suspend(struct device *dev) 1592{ 1593 /* 1594 * If the controller is autosuspended, there is no way to wakeup it once 1595 * runtime pm is disabled (in suspend_late()). 1596 * But a device may need the controller up during suspend_noirq() or 1597 * resume_noirq(). 1598 * Wakeup the controller while runtime pm is enabled, so it is available 1599 * until its suspend_noirq(), and from resume_noirq(). 1600 */ 1601 return pm_runtime_resume_and_get(dev); 1602} 1603 1604static int omap_i2c_resume(struct device *dev) 1605{ 1606 pm_runtime_put_autosuspend(dev); 1607 1608 return 0; 1609} 1610 1611static const struct dev_pm_ops omap_i2c_pm_ops = { 1612 NOIRQ_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend, 1613 pm_runtime_force_resume) 1614 SYSTEM_SLEEP_PM_OPS(omap_i2c_suspend, omap_i2c_resume) 1615 RUNTIME_PM_OPS(omap_i2c_runtime_suspend, 1616 omap_i2c_runtime_resume, NULL) 1617}; 1618 1619static struct platform_driver omap_i2c_driver = { 1620 .probe = omap_i2c_probe, 1621 .remove = omap_i2c_remove, 1622 .driver = { 1623 .name = "omap_i2c", 1624 .pm = pm_ptr(&omap_i2c_pm_ops), 1625 .of_match_table = of_match_ptr(omap_i2c_of_match), 1626 }, 1627}; 1628 1629/* I2C may be needed to bring up other drivers */ 1630static int __init 1631omap_i2c_init_driver(void) 1632{ 1633 return platform_driver_register(&omap_i2c_driver); 1634} 1635subsys_initcall(omap_i2c_init_driver); 1636 1637static void __exit omap_i2c_exit_driver(void) 1638{ 1639 platform_driver_unregister(&omap_i2c_driver); 1640} 1641module_exit(omap_i2c_exit_driver); 1642 1643MODULE_AUTHOR("MontaVista Software, Inc. (and others)"); 1644MODULE_DESCRIPTION("TI OMAP I2C bus adapter"); 1645MODULE_LICENSE("GPL"); 1646MODULE_ALIAS("platform:omap_i2c");
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