Bjorn Andersson | 10c5a84 | 2014-03-13 19:07:43 -0700 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2009-2013, The Linux Foundation. All rights reserved. |
| 3 | * Copyright (c) 2014, Sony Mobile Communications AB. |
| 4 | * |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify |
| 7 | * it under the terms of the GNU General Public License version 2 and |
| 8 | * only version 2 as published by the Free Software Foundation. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, |
| 11 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 13 | * GNU General Public License for more details. |
| 14 | * |
| 15 | */ |
| 16 | |
| 17 | #include <linux/clk.h> |
| 18 | #include <linux/delay.h> |
| 19 | #include <linux/err.h> |
| 20 | #include <linux/i2c.h> |
| 21 | #include <linux/interrupt.h> |
| 22 | #include <linux/io.h> |
| 23 | #include <linux/module.h> |
| 24 | #include <linux/of.h> |
| 25 | #include <linux/platform_device.h> |
| 26 | #include <linux/pm_runtime.h> |
| 27 | |
| 28 | /* QUP Registers */ |
| 29 | #define QUP_CONFIG 0x000 |
| 30 | #define QUP_STATE 0x004 |
| 31 | #define QUP_IO_MODE 0x008 |
| 32 | #define QUP_SW_RESET 0x00c |
| 33 | #define QUP_OPERATIONAL 0x018 |
| 34 | #define QUP_ERROR_FLAGS 0x01c |
| 35 | #define QUP_ERROR_FLAGS_EN 0x020 |
| 36 | #define QUP_HW_VERSION 0x030 |
| 37 | #define QUP_MX_OUTPUT_CNT 0x100 |
| 38 | #define QUP_OUT_FIFO_BASE 0x110 |
| 39 | #define QUP_MX_WRITE_CNT 0x150 |
| 40 | #define QUP_MX_INPUT_CNT 0x200 |
| 41 | #define QUP_MX_READ_CNT 0x208 |
| 42 | #define QUP_IN_FIFO_BASE 0x218 |
| 43 | #define QUP_I2C_CLK_CTL 0x400 |
| 44 | #define QUP_I2C_STATUS 0x404 |
| 45 | |
| 46 | /* QUP States and reset values */ |
| 47 | #define QUP_RESET_STATE 0 |
| 48 | #define QUP_RUN_STATE 1 |
| 49 | #define QUP_PAUSE_STATE 3 |
| 50 | #define QUP_STATE_MASK 3 |
| 51 | |
| 52 | #define QUP_STATE_VALID BIT(2) |
| 53 | #define QUP_I2C_MAST_GEN BIT(4) |
| 54 | |
| 55 | #define QUP_OPERATIONAL_RESET 0x000ff0 |
| 56 | #define QUP_I2C_STATUS_RESET 0xfffffc |
| 57 | |
| 58 | /* QUP OPERATIONAL FLAGS */ |
| 59 | #define QUP_I2C_NACK_FLAG BIT(3) |
| 60 | #define QUP_OUT_NOT_EMPTY BIT(4) |
| 61 | #define QUP_IN_NOT_EMPTY BIT(5) |
| 62 | #define QUP_OUT_FULL BIT(6) |
| 63 | #define QUP_OUT_SVC_FLAG BIT(8) |
| 64 | #define QUP_IN_SVC_FLAG BIT(9) |
| 65 | #define QUP_MX_OUTPUT_DONE BIT(10) |
| 66 | #define QUP_MX_INPUT_DONE BIT(11) |
| 67 | |
| 68 | /* I2C mini core related values */ |
| 69 | #define QUP_CLOCK_AUTO_GATE BIT(13) |
| 70 | #define I2C_MINI_CORE (2 << 8) |
| 71 | #define I2C_N_VAL 15 |
| 72 | /* Most significant word offset in FIFO port */ |
| 73 | #define QUP_MSW_SHIFT (I2C_N_VAL + 1) |
| 74 | |
| 75 | /* Packing/Unpacking words in FIFOs, and IO modes */ |
| 76 | #define QUP_OUTPUT_BLK_MODE (1 << 10) |
| 77 | #define QUP_INPUT_BLK_MODE (1 << 12) |
| 78 | #define QUP_UNPACK_EN BIT(14) |
| 79 | #define QUP_PACK_EN BIT(15) |
| 80 | |
| 81 | #define QUP_REPACK_EN (QUP_UNPACK_EN | QUP_PACK_EN) |
| 82 | |
| 83 | #define QUP_OUTPUT_BLOCK_SIZE(x)(((x) >> 0) & 0x03) |
| 84 | #define QUP_OUTPUT_FIFO_SIZE(x) (((x) >> 2) & 0x07) |
| 85 | #define QUP_INPUT_BLOCK_SIZE(x) (((x) >> 5) & 0x03) |
| 86 | #define QUP_INPUT_FIFO_SIZE(x) (((x) >> 7) & 0x07) |
| 87 | |
| 88 | /* QUP tags */ |
| 89 | #define QUP_TAG_START (1 << 8) |
| 90 | #define QUP_TAG_DATA (2 << 8) |
| 91 | #define QUP_TAG_STOP (3 << 8) |
| 92 | #define QUP_TAG_REC (4 << 8) |
| 93 | |
| 94 | /* Status, Error flags */ |
| 95 | #define I2C_STATUS_WR_BUFFER_FULL BIT(0) |
| 96 | #define I2C_STATUS_BUS_ACTIVE BIT(8) |
| 97 | #define I2C_STATUS_ERROR_MASK 0x38000fc |
| 98 | #define QUP_STATUS_ERROR_FLAGS 0x7c |
| 99 | |
| 100 | #define QUP_READ_LIMIT 256 |
| 101 | |
| 102 | struct qup_i2c_dev { |
| 103 | struct device *dev; |
| 104 | void __iomem *base; |
| 105 | int irq; |
| 106 | struct clk *clk; |
| 107 | struct clk *pclk; |
| 108 | struct i2c_adapter adap; |
| 109 | |
| 110 | int clk_ctl; |
| 111 | int out_fifo_sz; |
| 112 | int in_fifo_sz; |
| 113 | int out_blk_sz; |
| 114 | int in_blk_sz; |
| 115 | |
| 116 | unsigned long one_byte_t; |
| 117 | |
| 118 | struct i2c_msg *msg; |
| 119 | /* Current posion in user message buffer */ |
| 120 | int pos; |
| 121 | /* I2C protocol errors */ |
| 122 | u32 bus_err; |
| 123 | /* QUP core errors */ |
| 124 | u32 qup_err; |
| 125 | |
| 126 | struct completion xfer; |
| 127 | }; |
| 128 | |
| 129 | static irqreturn_t qup_i2c_interrupt(int irq, void *dev) |
| 130 | { |
| 131 | struct qup_i2c_dev *qup = dev; |
| 132 | u32 bus_err; |
| 133 | u32 qup_err; |
| 134 | u32 opflags; |
| 135 | |
| 136 | bus_err = readl(qup->base + QUP_I2C_STATUS); |
| 137 | qup_err = readl(qup->base + QUP_ERROR_FLAGS); |
| 138 | opflags = readl(qup->base + QUP_OPERATIONAL); |
| 139 | |
| 140 | if (!qup->msg) { |
| 141 | /* Clear Error interrupt */ |
| 142 | writel(QUP_RESET_STATE, qup->base + QUP_STATE); |
| 143 | return IRQ_HANDLED; |
| 144 | } |
| 145 | |
| 146 | bus_err &= I2C_STATUS_ERROR_MASK; |
| 147 | qup_err &= QUP_STATUS_ERROR_FLAGS; |
| 148 | |
| 149 | if (qup_err) { |
| 150 | /* Clear Error interrupt */ |
| 151 | writel(qup_err, qup->base + QUP_ERROR_FLAGS); |
| 152 | goto done; |
| 153 | } |
| 154 | |
| 155 | if (bus_err) { |
| 156 | /* Clear Error interrupt */ |
| 157 | writel(QUP_RESET_STATE, qup->base + QUP_STATE); |
| 158 | goto done; |
| 159 | } |
| 160 | |
| 161 | if (opflags & QUP_IN_SVC_FLAG) |
| 162 | writel(QUP_IN_SVC_FLAG, qup->base + QUP_OPERATIONAL); |
| 163 | |
| 164 | if (opflags & QUP_OUT_SVC_FLAG) |
| 165 | writel(QUP_OUT_SVC_FLAG, qup->base + QUP_OPERATIONAL); |
| 166 | |
| 167 | done: |
| 168 | qup->qup_err = qup_err; |
| 169 | qup->bus_err = bus_err; |
| 170 | complete(&qup->xfer); |
| 171 | return IRQ_HANDLED; |
| 172 | } |
| 173 | |
| 174 | static int qup_i2c_poll_state_mask(struct qup_i2c_dev *qup, |
| 175 | u32 req_state, u32 req_mask) |
| 176 | { |
| 177 | int retries = 1; |
| 178 | u32 state; |
| 179 | |
| 180 | /* |
| 181 | * State transition takes 3 AHB clocks cycles + 3 I2C master clock |
| 182 | * cycles. So retry once after a 1uS delay. |
| 183 | */ |
| 184 | do { |
| 185 | state = readl(qup->base + QUP_STATE); |
| 186 | |
| 187 | if (state & QUP_STATE_VALID && |
| 188 | (state & req_mask) == req_state) |
| 189 | return 0; |
| 190 | |
| 191 | udelay(1); |
| 192 | } while (retries--); |
| 193 | |
| 194 | return -ETIMEDOUT; |
| 195 | } |
| 196 | |
| 197 | static int qup_i2c_poll_state(struct qup_i2c_dev *qup, u32 req_state) |
| 198 | { |
| 199 | return qup_i2c_poll_state_mask(qup, req_state, QUP_STATE_MASK); |
| 200 | } |
| 201 | |
| 202 | static int qup_i2c_poll_state_valid(struct qup_i2c_dev *qup) |
| 203 | { |
| 204 | return qup_i2c_poll_state_mask(qup, 0, 0); |
| 205 | } |
| 206 | |
| 207 | static int qup_i2c_poll_state_i2c_master(struct qup_i2c_dev *qup) |
| 208 | { |
| 209 | return qup_i2c_poll_state_mask(qup, QUP_I2C_MAST_GEN, QUP_I2C_MAST_GEN); |
| 210 | } |
| 211 | |
| 212 | static int qup_i2c_change_state(struct qup_i2c_dev *qup, u32 state) |
| 213 | { |
| 214 | if (qup_i2c_poll_state_valid(qup) != 0) |
| 215 | return -EIO; |
| 216 | |
| 217 | writel(state, qup->base + QUP_STATE); |
| 218 | |
| 219 | if (qup_i2c_poll_state(qup, state) != 0) |
| 220 | return -EIO; |
| 221 | return 0; |
| 222 | } |
| 223 | |
| 224 | static int qup_i2c_wait_writeready(struct qup_i2c_dev *qup) |
| 225 | { |
| 226 | unsigned long timeout; |
| 227 | u32 opflags; |
| 228 | u32 status; |
| 229 | |
| 230 | timeout = jiffies + HZ; |
| 231 | |
| 232 | for (;;) { |
| 233 | opflags = readl(qup->base + QUP_OPERATIONAL); |
| 234 | status = readl(qup->base + QUP_I2C_STATUS); |
| 235 | |
| 236 | if (!(opflags & QUP_OUT_NOT_EMPTY) && |
| 237 | !(status & I2C_STATUS_BUS_ACTIVE)) |
| 238 | return 0; |
| 239 | |
| 240 | if (time_after(jiffies, timeout)) |
| 241 | return -ETIMEDOUT; |
| 242 | |
| 243 | usleep_range(qup->one_byte_t, qup->one_byte_t * 2); |
| 244 | } |
| 245 | } |
| 246 | |
| 247 | static void qup_i2c_set_write_mode(struct qup_i2c_dev *qup, struct i2c_msg *msg) |
| 248 | { |
| 249 | /* Number of entries to shift out, including the start */ |
| 250 | int total = msg->len + 1; |
| 251 | |
| 252 | if (total < qup->out_fifo_sz) { |
| 253 | /* FIFO mode */ |
| 254 | writel(QUP_REPACK_EN, qup->base + QUP_IO_MODE); |
| 255 | writel(total, qup->base + QUP_MX_WRITE_CNT); |
| 256 | } else { |
| 257 | /* BLOCK mode (transfer data on chunks) */ |
| 258 | writel(QUP_OUTPUT_BLK_MODE | QUP_REPACK_EN, |
| 259 | qup->base + QUP_IO_MODE); |
| 260 | writel(total, qup->base + QUP_MX_OUTPUT_CNT); |
| 261 | } |
| 262 | } |
| 263 | |
| 264 | static void qup_i2c_issue_write(struct qup_i2c_dev *qup, struct i2c_msg *msg) |
| 265 | { |
| 266 | u32 addr = msg->addr << 1; |
| 267 | u32 qup_tag; |
| 268 | u32 opflags; |
| 269 | int idx; |
| 270 | u32 val; |
| 271 | |
| 272 | if (qup->pos == 0) { |
| 273 | val = QUP_TAG_START | addr; |
| 274 | idx = 1; |
| 275 | } else { |
| 276 | val = 0; |
| 277 | idx = 0; |
| 278 | } |
| 279 | |
| 280 | while (qup->pos < msg->len) { |
| 281 | /* Check that there's space in the FIFO for our pair */ |
| 282 | opflags = readl(qup->base + QUP_OPERATIONAL); |
| 283 | if (opflags & QUP_OUT_FULL) |
| 284 | break; |
| 285 | |
| 286 | if (qup->pos == msg->len - 1) |
| 287 | qup_tag = QUP_TAG_STOP; |
| 288 | else |
| 289 | qup_tag = QUP_TAG_DATA; |
| 290 | |
| 291 | if (idx & 1) |
| 292 | val |= (qup_tag | msg->buf[qup->pos]) << QUP_MSW_SHIFT; |
| 293 | else |
| 294 | val = qup_tag | msg->buf[qup->pos]; |
| 295 | |
| 296 | /* Write out the pair and the last odd value */ |
| 297 | if (idx & 1 || qup->pos == msg->len - 1) |
| 298 | writel(val, qup->base + QUP_OUT_FIFO_BASE); |
| 299 | |
| 300 | qup->pos++; |
| 301 | idx++; |
| 302 | } |
| 303 | } |
| 304 | |
| 305 | static int qup_i2c_write_one(struct qup_i2c_dev *qup, struct i2c_msg *msg) |
| 306 | { |
| 307 | unsigned long left; |
| 308 | int ret; |
| 309 | |
| 310 | qup->msg = msg; |
| 311 | qup->pos = 0; |
| 312 | |
| 313 | enable_irq(qup->irq); |
| 314 | |
| 315 | qup_i2c_set_write_mode(qup, msg); |
| 316 | |
| 317 | ret = qup_i2c_change_state(qup, QUP_RUN_STATE); |
| 318 | if (ret) |
| 319 | goto err; |
| 320 | |
| 321 | writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL); |
| 322 | |
| 323 | do { |
| 324 | ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE); |
| 325 | if (ret) |
| 326 | goto err; |
| 327 | |
| 328 | qup_i2c_issue_write(qup, msg); |
| 329 | |
| 330 | ret = qup_i2c_change_state(qup, QUP_RUN_STATE); |
| 331 | if (ret) |
| 332 | goto err; |
| 333 | |
| 334 | left = wait_for_completion_timeout(&qup->xfer, HZ); |
| 335 | if (!left) { |
| 336 | writel(1, qup->base + QUP_SW_RESET); |
| 337 | ret = -ETIMEDOUT; |
| 338 | goto err; |
| 339 | } |
| 340 | |
| 341 | if (qup->bus_err || qup->qup_err) { |
| 342 | if (qup->bus_err & QUP_I2C_NACK_FLAG) |
| 343 | dev_err(qup->dev, "NACK from %x\n", msg->addr); |
| 344 | ret = -EIO; |
| 345 | goto err; |
| 346 | } |
| 347 | } while (qup->pos < msg->len); |
| 348 | |
| 349 | /* Wait for the outstanding data in the fifo to drain */ |
| 350 | ret = qup_i2c_wait_writeready(qup); |
| 351 | |
| 352 | err: |
| 353 | disable_irq(qup->irq); |
| 354 | qup->msg = NULL; |
| 355 | |
| 356 | return ret; |
| 357 | } |
| 358 | |
| 359 | static void qup_i2c_set_read_mode(struct qup_i2c_dev *qup, int len) |
| 360 | { |
| 361 | if (len < qup->in_fifo_sz) { |
| 362 | /* FIFO mode */ |
| 363 | writel(QUP_REPACK_EN, qup->base + QUP_IO_MODE); |
| 364 | writel(len, qup->base + QUP_MX_READ_CNT); |
| 365 | } else { |
| 366 | /* BLOCK mode (transfer data on chunks) */ |
| 367 | writel(QUP_INPUT_BLK_MODE | QUP_REPACK_EN, |
| 368 | qup->base + QUP_IO_MODE); |
| 369 | writel(len, qup->base + QUP_MX_INPUT_CNT); |
| 370 | } |
| 371 | } |
| 372 | |
| 373 | static void qup_i2c_issue_read(struct qup_i2c_dev *qup, struct i2c_msg *msg) |
| 374 | { |
| 375 | u32 addr, len, val; |
| 376 | |
| 377 | addr = (msg->addr << 1) | 1; |
| 378 | |
| 379 | /* 0 is used to specify a length 256 (QUP_READ_LIMIT) */ |
| 380 | len = (msg->len == QUP_READ_LIMIT) ? 0 : msg->len; |
| 381 | |
| 382 | val = ((QUP_TAG_REC | len) << QUP_MSW_SHIFT) | QUP_TAG_START | addr; |
| 383 | writel(val, qup->base + QUP_OUT_FIFO_BASE); |
| 384 | } |
| 385 | |
| 386 | |
| 387 | static void qup_i2c_read_fifo(struct qup_i2c_dev *qup, struct i2c_msg *msg) |
| 388 | { |
| 389 | u32 opflags; |
| 390 | u32 val = 0; |
| 391 | int idx; |
| 392 | |
| 393 | for (idx = 0; qup->pos < msg->len; idx++) { |
| 394 | if ((idx & 1) == 0) { |
| 395 | /* Check that FIFO have data */ |
| 396 | opflags = readl(qup->base + QUP_OPERATIONAL); |
| 397 | if (!(opflags & QUP_IN_NOT_EMPTY)) |
| 398 | break; |
| 399 | |
| 400 | /* Reading 2 words at time */ |
| 401 | val = readl(qup->base + QUP_IN_FIFO_BASE); |
| 402 | |
| 403 | msg->buf[qup->pos++] = val & 0xFF; |
| 404 | } else { |
| 405 | msg->buf[qup->pos++] = val >> QUP_MSW_SHIFT; |
| 406 | } |
| 407 | } |
| 408 | } |
| 409 | |
| 410 | static int qup_i2c_read_one(struct qup_i2c_dev *qup, struct i2c_msg *msg) |
| 411 | { |
| 412 | unsigned long left; |
| 413 | int ret; |
| 414 | |
| 415 | /* |
| 416 | * The QUP block will issue a NACK and STOP on the bus when reaching |
| 417 | * the end of the read, the length of the read is specified as one byte |
| 418 | * which limits the possible read to 256 (QUP_READ_LIMIT) bytes. |
| 419 | */ |
| 420 | if (msg->len > QUP_READ_LIMIT) { |
| 421 | dev_err(qup->dev, "HW not capable of reads over %d bytes\n", |
| 422 | QUP_READ_LIMIT); |
| 423 | return -EINVAL; |
| 424 | } |
| 425 | |
| 426 | qup->msg = msg; |
| 427 | qup->pos = 0; |
| 428 | |
| 429 | enable_irq(qup->irq); |
| 430 | |
| 431 | qup_i2c_set_read_mode(qup, msg->len); |
| 432 | |
| 433 | ret = qup_i2c_change_state(qup, QUP_RUN_STATE); |
| 434 | if (ret) |
| 435 | goto err; |
| 436 | |
| 437 | writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL); |
| 438 | |
| 439 | ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE); |
| 440 | if (ret) |
| 441 | goto err; |
| 442 | |
| 443 | qup_i2c_issue_read(qup, msg); |
| 444 | |
| 445 | ret = qup_i2c_change_state(qup, QUP_RUN_STATE); |
| 446 | if (ret) |
| 447 | goto err; |
| 448 | |
| 449 | do { |
| 450 | left = wait_for_completion_timeout(&qup->xfer, HZ); |
| 451 | if (!left) { |
| 452 | writel(1, qup->base + QUP_SW_RESET); |
| 453 | ret = -ETIMEDOUT; |
| 454 | goto err; |
| 455 | } |
| 456 | |
| 457 | if (qup->bus_err || qup->qup_err) { |
| 458 | if (qup->bus_err & QUP_I2C_NACK_FLAG) |
| 459 | dev_err(qup->dev, "NACK from %x\n", msg->addr); |
| 460 | ret = -EIO; |
| 461 | goto err; |
| 462 | } |
| 463 | |
| 464 | qup_i2c_read_fifo(qup, msg); |
| 465 | } while (qup->pos < msg->len); |
| 466 | |
| 467 | err: |
| 468 | disable_irq(qup->irq); |
| 469 | qup->msg = NULL; |
| 470 | |
| 471 | return ret; |
| 472 | } |
| 473 | |
| 474 | static int qup_i2c_xfer(struct i2c_adapter *adap, |
| 475 | struct i2c_msg msgs[], |
| 476 | int num) |
| 477 | { |
| 478 | struct qup_i2c_dev *qup = i2c_get_adapdata(adap); |
| 479 | int ret, idx; |
| 480 | |
| 481 | ret = pm_runtime_get_sync(qup->dev); |
Andy Gross | fa01d09 | 2014-05-02 20:54:29 -0500 | [diff] [blame] | 482 | if (ret < 0) |
Bjorn Andersson | 10c5a84 | 2014-03-13 19:07:43 -0700 | [diff] [blame] | 483 | goto out; |
| 484 | |
| 485 | writel(1, qup->base + QUP_SW_RESET); |
| 486 | ret = qup_i2c_poll_state(qup, QUP_RESET_STATE); |
| 487 | if (ret) |
| 488 | goto out; |
| 489 | |
| 490 | /* Configure QUP as I2C mini core */ |
| 491 | writel(I2C_MINI_CORE | I2C_N_VAL, qup->base + QUP_CONFIG); |
| 492 | |
| 493 | for (idx = 0; idx < num; idx++) { |
| 494 | if (msgs[idx].len == 0) { |
| 495 | ret = -EINVAL; |
| 496 | goto out; |
| 497 | } |
| 498 | |
| 499 | if (qup_i2c_poll_state_i2c_master(qup)) { |
| 500 | ret = -EIO; |
| 501 | goto out; |
| 502 | } |
| 503 | |
| 504 | if (msgs[idx].flags & I2C_M_RD) |
| 505 | ret = qup_i2c_read_one(qup, &msgs[idx]); |
| 506 | else |
| 507 | ret = qup_i2c_write_one(qup, &msgs[idx]); |
| 508 | |
| 509 | if (ret) |
| 510 | break; |
| 511 | |
| 512 | ret = qup_i2c_change_state(qup, QUP_RESET_STATE); |
| 513 | if (ret) |
| 514 | break; |
| 515 | } |
| 516 | |
| 517 | if (ret == 0) |
| 518 | ret = num; |
| 519 | out: |
| 520 | |
| 521 | pm_runtime_mark_last_busy(qup->dev); |
| 522 | pm_runtime_put_autosuspend(qup->dev); |
| 523 | |
| 524 | return ret; |
| 525 | } |
| 526 | |
| 527 | static u32 qup_i2c_func(struct i2c_adapter *adap) |
| 528 | { |
| 529 | return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); |
| 530 | } |
| 531 | |
| 532 | static const struct i2c_algorithm qup_i2c_algo = { |
| 533 | .master_xfer = qup_i2c_xfer, |
| 534 | .functionality = qup_i2c_func, |
| 535 | }; |
| 536 | |
| 537 | static void qup_i2c_enable_clocks(struct qup_i2c_dev *qup) |
| 538 | { |
| 539 | clk_prepare_enable(qup->clk); |
| 540 | clk_prepare_enable(qup->pclk); |
| 541 | } |
| 542 | |
| 543 | static void qup_i2c_disable_clocks(struct qup_i2c_dev *qup) |
| 544 | { |
| 545 | u32 config; |
| 546 | |
| 547 | qup_i2c_change_state(qup, QUP_RESET_STATE); |
| 548 | clk_disable_unprepare(qup->clk); |
| 549 | config = readl(qup->base + QUP_CONFIG); |
| 550 | config |= QUP_CLOCK_AUTO_GATE; |
| 551 | writel(config, qup->base + QUP_CONFIG); |
| 552 | clk_disable_unprepare(qup->pclk); |
| 553 | } |
| 554 | |
| 555 | static int qup_i2c_probe(struct platform_device *pdev) |
| 556 | { |
| 557 | static const int blk_sizes[] = {4, 16, 32}; |
| 558 | struct device_node *node = pdev->dev.of_node; |
| 559 | struct qup_i2c_dev *qup; |
| 560 | unsigned long one_bit_t; |
| 561 | struct resource *res; |
| 562 | u32 io_mode, hw_ver, size; |
| 563 | int ret, fs_div, hs_div; |
| 564 | int src_clk_freq; |
Wolfram Sang | cf23e33 | 2014-04-03 11:30:33 +0200 | [diff] [blame] | 565 | u32 clk_freq = 100000; |
Bjorn Andersson | 10c5a84 | 2014-03-13 19:07:43 -0700 | [diff] [blame] | 566 | |
| 567 | qup = devm_kzalloc(&pdev->dev, sizeof(*qup), GFP_KERNEL); |
| 568 | if (!qup) |
| 569 | return -ENOMEM; |
| 570 | |
| 571 | qup->dev = &pdev->dev; |
| 572 | init_completion(&qup->xfer); |
| 573 | platform_set_drvdata(pdev, qup); |
| 574 | |
| 575 | of_property_read_u32(node, "clock-frequency", &clk_freq); |
| 576 | |
| 577 | /* We support frequencies up to FAST Mode (400KHz) */ |
| 578 | if (!clk_freq || clk_freq > 400000) { |
| 579 | dev_err(qup->dev, "clock frequency not supported %d\n", |
| 580 | clk_freq); |
| 581 | return -EINVAL; |
| 582 | } |
| 583 | |
| 584 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 585 | qup->base = devm_ioremap_resource(qup->dev, res); |
| 586 | if (IS_ERR(qup->base)) |
| 587 | return PTR_ERR(qup->base); |
| 588 | |
| 589 | qup->irq = platform_get_irq(pdev, 0); |
| 590 | if (qup->irq < 0) { |
| 591 | dev_err(qup->dev, "No IRQ defined\n"); |
| 592 | return qup->irq; |
| 593 | } |
| 594 | |
| 595 | qup->clk = devm_clk_get(qup->dev, "core"); |
| 596 | if (IS_ERR(qup->clk)) { |
| 597 | dev_err(qup->dev, "Could not get core clock\n"); |
| 598 | return PTR_ERR(qup->clk); |
| 599 | } |
| 600 | |
| 601 | qup->pclk = devm_clk_get(qup->dev, "iface"); |
| 602 | if (IS_ERR(qup->pclk)) { |
| 603 | dev_err(qup->dev, "Could not get iface clock\n"); |
| 604 | return PTR_ERR(qup->pclk); |
| 605 | } |
| 606 | |
| 607 | qup_i2c_enable_clocks(qup); |
| 608 | |
| 609 | /* |
| 610 | * Bootloaders might leave a pending interrupt on certain QUP's, |
| 611 | * so we reset the core before registering for interrupts. |
| 612 | */ |
| 613 | writel(1, qup->base + QUP_SW_RESET); |
| 614 | ret = qup_i2c_poll_state_valid(qup); |
| 615 | if (ret) |
| 616 | goto fail; |
| 617 | |
| 618 | ret = devm_request_irq(qup->dev, qup->irq, qup_i2c_interrupt, |
| 619 | IRQF_TRIGGER_HIGH, "i2c_qup", qup); |
| 620 | if (ret) { |
| 621 | dev_err(qup->dev, "Request %d IRQ failed\n", qup->irq); |
| 622 | goto fail; |
| 623 | } |
| 624 | disable_irq(qup->irq); |
| 625 | |
| 626 | hw_ver = readl(qup->base + QUP_HW_VERSION); |
| 627 | dev_dbg(qup->dev, "Revision %x\n", hw_ver); |
| 628 | |
| 629 | io_mode = readl(qup->base + QUP_IO_MODE); |
| 630 | |
| 631 | /* |
| 632 | * The block/fifo size w.r.t. 'actual data' is 1/2 due to 'tag' |
| 633 | * associated with each byte written/received |
| 634 | */ |
| 635 | size = QUP_OUTPUT_BLOCK_SIZE(io_mode); |
Pramod Gurav | 3cf357d | 2014-08-06 18:03:25 +0530 | [diff] [blame] | 636 | if (size >= ARRAY_SIZE(blk_sizes)) { |
| 637 | ret = -EIO; |
| 638 | goto fail; |
| 639 | } |
Bjorn Andersson | 10c5a84 | 2014-03-13 19:07:43 -0700 | [diff] [blame] | 640 | qup->out_blk_sz = blk_sizes[size] / 2; |
| 641 | |
| 642 | size = QUP_INPUT_BLOCK_SIZE(io_mode); |
Pramod Gurav | 3cf357d | 2014-08-06 18:03:25 +0530 | [diff] [blame] | 643 | if (size >= ARRAY_SIZE(blk_sizes)) { |
| 644 | ret = -EIO; |
| 645 | goto fail; |
| 646 | } |
Bjorn Andersson | 10c5a84 | 2014-03-13 19:07:43 -0700 | [diff] [blame] | 647 | qup->in_blk_sz = blk_sizes[size] / 2; |
| 648 | |
| 649 | size = QUP_OUTPUT_FIFO_SIZE(io_mode); |
| 650 | qup->out_fifo_sz = qup->out_blk_sz * (2 << size); |
| 651 | |
| 652 | size = QUP_INPUT_FIFO_SIZE(io_mode); |
| 653 | qup->in_fifo_sz = qup->in_blk_sz * (2 << size); |
| 654 | |
| 655 | src_clk_freq = clk_get_rate(qup->clk); |
| 656 | fs_div = ((src_clk_freq / clk_freq) / 2) - 3; |
| 657 | hs_div = 3; |
| 658 | qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff); |
| 659 | |
| 660 | /* |
| 661 | * Time it takes for a byte to be clocked out on the bus. |
| 662 | * Each byte takes 9 clock cycles (8 bits + 1 ack). |
| 663 | */ |
| 664 | one_bit_t = (USEC_PER_SEC / clk_freq) + 1; |
| 665 | qup->one_byte_t = one_bit_t * 9; |
| 666 | |
| 667 | dev_dbg(qup->dev, "IN:block:%d, fifo:%d, OUT:block:%d, fifo:%d\n", |
| 668 | qup->in_blk_sz, qup->in_fifo_sz, |
| 669 | qup->out_blk_sz, qup->out_fifo_sz); |
| 670 | |
| 671 | i2c_set_adapdata(&qup->adap, qup); |
| 672 | qup->adap.algo = &qup_i2c_algo; |
| 673 | qup->adap.dev.parent = qup->dev; |
| 674 | qup->adap.dev.of_node = pdev->dev.of_node; |
| 675 | strlcpy(qup->adap.name, "QUP I2C adapter", sizeof(qup->adap.name)); |
| 676 | |
| 677 | ret = i2c_add_adapter(&qup->adap); |
| 678 | if (ret) |
| 679 | goto fail; |
| 680 | |
| 681 | pm_runtime_set_autosuspend_delay(qup->dev, MSEC_PER_SEC); |
| 682 | pm_runtime_use_autosuspend(qup->dev); |
| 683 | pm_runtime_set_active(qup->dev); |
| 684 | pm_runtime_enable(qup->dev); |
| 685 | return 0; |
| 686 | |
| 687 | fail: |
| 688 | qup_i2c_disable_clocks(qup); |
| 689 | return ret; |
| 690 | } |
| 691 | |
| 692 | static int qup_i2c_remove(struct platform_device *pdev) |
| 693 | { |
| 694 | struct qup_i2c_dev *qup = platform_get_drvdata(pdev); |
| 695 | |
| 696 | disable_irq(qup->irq); |
| 697 | qup_i2c_disable_clocks(qup); |
| 698 | i2c_del_adapter(&qup->adap); |
| 699 | pm_runtime_disable(qup->dev); |
| 700 | pm_runtime_set_suspended(qup->dev); |
| 701 | return 0; |
| 702 | } |
| 703 | |
| 704 | #ifdef CONFIG_PM |
| 705 | static int qup_i2c_pm_suspend_runtime(struct device *device) |
| 706 | { |
| 707 | struct qup_i2c_dev *qup = dev_get_drvdata(device); |
| 708 | |
| 709 | dev_dbg(device, "pm_runtime: suspending...\n"); |
| 710 | qup_i2c_disable_clocks(qup); |
| 711 | return 0; |
| 712 | } |
| 713 | |
| 714 | static int qup_i2c_pm_resume_runtime(struct device *device) |
| 715 | { |
| 716 | struct qup_i2c_dev *qup = dev_get_drvdata(device); |
| 717 | |
| 718 | dev_dbg(device, "pm_runtime: resuming...\n"); |
| 719 | qup_i2c_enable_clocks(qup); |
| 720 | return 0; |
| 721 | } |
| 722 | #endif |
| 723 | |
| 724 | #ifdef CONFIG_PM_SLEEP |
| 725 | static int qup_i2c_suspend(struct device *device) |
| 726 | { |
| 727 | qup_i2c_pm_suspend_runtime(device); |
| 728 | return 0; |
| 729 | } |
| 730 | |
| 731 | static int qup_i2c_resume(struct device *device) |
| 732 | { |
| 733 | qup_i2c_pm_resume_runtime(device); |
| 734 | pm_runtime_mark_last_busy(device); |
| 735 | pm_request_autosuspend(device); |
| 736 | return 0; |
| 737 | } |
| 738 | #endif |
| 739 | |
| 740 | static const struct dev_pm_ops qup_i2c_qup_pm_ops = { |
| 741 | SET_SYSTEM_SLEEP_PM_OPS( |
| 742 | qup_i2c_suspend, |
| 743 | qup_i2c_resume) |
| 744 | SET_RUNTIME_PM_OPS( |
| 745 | qup_i2c_pm_suspend_runtime, |
| 746 | qup_i2c_pm_resume_runtime, |
| 747 | NULL) |
| 748 | }; |
| 749 | |
| 750 | static const struct of_device_id qup_i2c_dt_match[] = { |
| 751 | { .compatible = "qcom,i2c-qup-v1.1.1" }, |
| 752 | { .compatible = "qcom,i2c-qup-v2.1.1" }, |
| 753 | { .compatible = "qcom,i2c-qup-v2.2.1" }, |
| 754 | {} |
| 755 | }; |
| 756 | MODULE_DEVICE_TABLE(of, qup_i2c_dt_match); |
| 757 | |
| 758 | static struct platform_driver qup_i2c_driver = { |
| 759 | .probe = qup_i2c_probe, |
| 760 | .remove = qup_i2c_remove, |
| 761 | .driver = { |
| 762 | .name = "i2c_qup", |
| 763 | .owner = THIS_MODULE, |
| 764 | .pm = &qup_i2c_qup_pm_ops, |
| 765 | .of_match_table = qup_i2c_dt_match, |
| 766 | }, |
| 767 | }; |
| 768 | |
| 769 | module_platform_driver(qup_i2c_driver); |
| 770 | |
| 771 | MODULE_LICENSE("GPL v2"); |
| 772 | MODULE_ALIAS("platform:i2c_qup"); |