1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * Freescale i.MX7D ADC driver 4 * 5 * Copyright (C) 2015 Freescale Semiconductor, Inc. 6 */ 7 8 #include <linux/clk.h> 9 #include <linux/completion.h> 10 #include <linux/err.h> 11 #include <linux/interrupt.h> 12 #include <linux/io.h> 13 #include <linux/kernel.h> 14 #include <linux/module.h> 15 #include <linux/platform_device.h> 16 #include <linux/regulator/consumer.h> 17 18 #include <linux/iio/iio.h> 19 #include <linux/iio/driver.h> 20 #include <linux/iio/sysfs.h> 21 22 /* ADC register */ 23 #define IMX7D_REG_ADC_CH_A_CFG1 0x00 24 #define IMX7D_REG_ADC_CH_A_CFG2 0x10 25 #define IMX7D_REG_ADC_CH_B_CFG1 0x20 26 #define IMX7D_REG_ADC_CH_B_CFG2 0x30 27 #define IMX7D_REG_ADC_CH_C_CFG1 0x40 28 #define IMX7D_REG_ADC_CH_C_CFG2 0x50 29 #define IMX7D_REG_ADC_CH_D_CFG1 0x60 30 #define IMX7D_REG_ADC_CH_D_CFG2 0x70 31 #define IMX7D_REG_ADC_CH_SW_CFG 0x80 32 #define IMX7D_REG_ADC_TIMER_UNIT 0x90 33 #define IMX7D_REG_ADC_DMA_FIFO 0xa0 34 #define IMX7D_REG_ADC_FIFO_STATUS 0xb0 35 #define IMX7D_REG_ADC_INT_SIG_EN 0xc0 36 #define IMX7D_REG_ADC_INT_EN 0xd0 37 #define IMX7D_REG_ADC_INT_STATUS 0xe0 38 #define IMX7D_REG_ADC_CHA_B_CNV_RSLT 0xf0 39 #define IMX7D_REG_ADC_CHC_D_CNV_RSLT 0x100 40 #define IMX7D_REG_ADC_CH_SW_CNV_RSLT 0x110 41 #define IMX7D_REG_ADC_DMA_FIFO_DAT 0x120 42 #define IMX7D_REG_ADC_ADC_CFG 0x130 43 44 #define IMX7D_REG_ADC_CHANNEL_CFG2_BASE 0x10 45 #define IMX7D_EACH_CHANNEL_REG_OFFSET 0x20 46 47 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN (0x1 << 31) 48 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE BIT(30) 49 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN BIT(29) 50 #define IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(x) ((x) << 24) 51 52 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4 (0x0 << 12) 53 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8 (0x1 << 12) 54 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16 (0x2 << 12) 55 #define IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32 (0x3 << 12) 56 57 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4 (0x0 << 29) 58 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8 (0x1 << 29) 59 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16 (0x2 << 29) 60 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32 (0x3 << 29) 61 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64 (0x4 << 29) 62 #define IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128 (0x5 << 29) 63 64 #define IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN BIT(31) 65 #define IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN BIT(1) 66 #define IMX7D_REG_ADC_ADC_CFG_ADC_EN BIT(0) 67 68 #define IMX7D_REG_ADC_INT_CHA_COV_INT_EN BIT(8) 69 #define IMX7D_REG_ADC_INT_CHB_COV_INT_EN BIT(9) 70 #define IMX7D_REG_ADC_INT_CHC_COV_INT_EN BIT(10) 71 #define IMX7D_REG_ADC_INT_CHD_COV_INT_EN BIT(11) 72 #define IMX7D_REG_ADC_INT_CHANNEL_INT_EN \ 73 (IMX7D_REG_ADC_INT_CHA_COV_INT_EN | \ 74 IMX7D_REG_ADC_INT_CHB_COV_INT_EN | \ 75 IMX7D_REG_ADC_INT_CHC_COV_INT_EN | \ 76 IMX7D_REG_ADC_INT_CHD_COV_INT_EN) 77 #define IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS 0xf00 78 #define IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT 0xf0000 79 80 #define IMX7D_ADC_TIMEOUT msecs_to_jiffies(100) 81 #define IMX7D_ADC_INPUT_CLK 24000000 82 83 enum imx7d_adc_clk_pre_div { 84 IMX7D_ADC_ANALOG_CLK_PRE_DIV_4, 85 IMX7D_ADC_ANALOG_CLK_PRE_DIV_8, 86 IMX7D_ADC_ANALOG_CLK_PRE_DIV_16, 87 IMX7D_ADC_ANALOG_CLK_PRE_DIV_32, 88 IMX7D_ADC_ANALOG_CLK_PRE_DIV_64, 89 IMX7D_ADC_ANALOG_CLK_PRE_DIV_128, 90 }; 91 92 enum imx7d_adc_average_num { 93 IMX7D_ADC_AVERAGE_NUM_4, 94 IMX7D_ADC_AVERAGE_NUM_8, 95 IMX7D_ADC_AVERAGE_NUM_16, 96 IMX7D_ADC_AVERAGE_NUM_32, 97 }; 98 99 struct imx7d_adc_feature { 100 enum imx7d_adc_clk_pre_div clk_pre_div; 101 enum imx7d_adc_average_num avg_num; 102 103 u32 core_time_unit; /* impact the sample rate */ 104 }; 105 106 struct imx7d_adc { 107 struct device *dev; 108 void __iomem *regs; 109 struct clk *clk; 110 111 u32 vref_uv; 112 u32 value; 113 u32 channel; 114 u32 pre_div_num; 115 116 struct regulator *vref; 117 struct imx7d_adc_feature adc_feature; 118 119 struct completion completion; 120 }; 121 122 struct imx7d_adc_analogue_core_clk { 123 u32 pre_div; 124 u32 reg_config; 125 }; 126 127 #define IMX7D_ADC_ANALOGUE_CLK_CONFIG(_pre_div, _reg_conf) { \ 128 .pre_div = (_pre_div), \ 129 .reg_config = (_reg_conf), \ 130 } 131 132 static const struct imx7d_adc_analogue_core_clk imx7d_adc_analogue_clk[] = { 133 IMX7D_ADC_ANALOGUE_CLK_CONFIG(4, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_4), 134 IMX7D_ADC_ANALOGUE_CLK_CONFIG(8, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_8), 135 IMX7D_ADC_ANALOGUE_CLK_CONFIG(16, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_16), 136 IMX7D_ADC_ANALOGUE_CLK_CONFIG(32, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_32), 137 IMX7D_ADC_ANALOGUE_CLK_CONFIG(64, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_64), 138 IMX7D_ADC_ANALOGUE_CLK_CONFIG(128, IMX7D_REG_ADC_TIMER_UNIT_PRE_DIV_128), 139 }; 140 141 #define IMX7D_ADC_CHAN(_idx) { \ 142 .type = IIO_VOLTAGE, \ 143 .indexed = 1, \ 144 .channel = (_idx), \ 145 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 146 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ 147 BIT(IIO_CHAN_INFO_SAMP_FREQ), \ 148 } 149 150 static const struct iio_chan_spec imx7d_adc_iio_channels[] = { 151 IMX7D_ADC_CHAN(0), 152 IMX7D_ADC_CHAN(1), 153 IMX7D_ADC_CHAN(2), 154 IMX7D_ADC_CHAN(3), 155 IMX7D_ADC_CHAN(4), 156 IMX7D_ADC_CHAN(5), 157 IMX7D_ADC_CHAN(6), 158 IMX7D_ADC_CHAN(7), 159 IMX7D_ADC_CHAN(8), 160 IMX7D_ADC_CHAN(9), 161 IMX7D_ADC_CHAN(10), 162 IMX7D_ADC_CHAN(11), 163 IMX7D_ADC_CHAN(12), 164 IMX7D_ADC_CHAN(13), 165 IMX7D_ADC_CHAN(14), 166 IMX7D_ADC_CHAN(15), 167 }; 168 169 static const u32 imx7d_adc_average_num[] = { 170 IMX7D_REG_ADC_CH_CFG2_AVG_NUM_4, 171 IMX7D_REG_ADC_CH_CFG2_AVG_NUM_8, 172 IMX7D_REG_ADC_CH_CFG2_AVG_NUM_16, 173 IMX7D_REG_ADC_CH_CFG2_AVG_NUM_32, 174 }; 175 176 static void imx7d_adc_feature_config(struct imx7d_adc *info) 177 { 178 info->adc_feature.clk_pre_div = IMX7D_ADC_ANALOG_CLK_PRE_DIV_4; 179 info->adc_feature.avg_num = IMX7D_ADC_AVERAGE_NUM_32; 180 info->adc_feature.core_time_unit = 1; 181 } 182 183 static void imx7d_adc_sample_rate_set(struct imx7d_adc *info) 184 { 185 struct imx7d_adc_feature *adc_feature = &info->adc_feature; 186 struct imx7d_adc_analogue_core_clk adc_analogure_clk; 187 u32 i; 188 u32 tmp_cfg1; 189 u32 sample_rate = 0; 190 191 /* 192 * Before sample set, disable channel A,B,C,D. Here we 193 * clear the bit 31 of register REG_ADC_CH_A\B\C\D_CFG1. 194 */ 195 for (i = 0; i < 4; i++) { 196 tmp_cfg1 = 197 readl(info->regs + i * IMX7D_EACH_CHANNEL_REG_OFFSET); 198 tmp_cfg1 &= ~IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN; 199 writel(tmp_cfg1, 200 info->regs + i * IMX7D_EACH_CHANNEL_REG_OFFSET); 201 } 202 203 adc_analogure_clk = imx7d_adc_analogue_clk[adc_feature->clk_pre_div]; 204 sample_rate |= adc_analogure_clk.reg_config; 205 info->pre_div_num = adc_analogure_clk.pre_div; 206 207 sample_rate |= adc_feature->core_time_unit; 208 writel(sample_rate, info->regs + IMX7D_REG_ADC_TIMER_UNIT); 209 } 210 211 static void imx7d_adc_hw_init(struct imx7d_adc *info) 212 { 213 u32 cfg; 214 215 /* power up and enable adc analogue core */ 216 cfg = readl(info->regs + IMX7D_REG_ADC_ADC_CFG); 217 cfg &= ~(IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN | 218 IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN); 219 cfg |= IMX7D_REG_ADC_ADC_CFG_ADC_EN; 220 writel(cfg, info->regs + IMX7D_REG_ADC_ADC_CFG); 221 222 /* enable channel A,B,C,D interrupt */ 223 writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN, 224 info->regs + IMX7D_REG_ADC_INT_SIG_EN); 225 writel(IMX7D_REG_ADC_INT_CHANNEL_INT_EN, 226 info->regs + IMX7D_REG_ADC_INT_EN); 227 228 imx7d_adc_sample_rate_set(info); 229 } 230 231 static void imx7d_adc_channel_set(struct imx7d_adc *info) 232 { 233 u32 cfg1 = 0; 234 u32 cfg2; 235 u32 channel; 236 237 channel = info->channel; 238 239 /* the channel choose single conversion, and enable average mode */ 240 cfg1 |= (IMX7D_REG_ADC_CH_CFG1_CHANNEL_EN | 241 IMX7D_REG_ADC_CH_CFG1_CHANNEL_SINGLE | 242 IMX7D_REG_ADC_CH_CFG1_CHANNEL_AVG_EN); 243 244 /* 245 * physical channel 0 chose logical channel A 246 * physical channel 1 chose logical channel B 247 * physical channel 2 chose logical channel C 248 * physical channel 3 chose logical channel D 249 */ 250 cfg1 |= IMX7D_REG_ADC_CH_CFG1_CHANNEL_SEL(channel); 251 252 /* 253 * read register REG_ADC_CH_A\B\C\D_CFG2, according to the 254 * channel chosen 255 */ 256 cfg2 = readl(info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel + 257 IMX7D_REG_ADC_CHANNEL_CFG2_BASE); 258 259 cfg2 |= imx7d_adc_average_num[info->adc_feature.avg_num]; 260 261 /* 262 * write the register REG_ADC_CH_A\B\C\D_CFG2, according to 263 * the channel chosen 264 */ 265 writel(cfg2, info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel + 266 IMX7D_REG_ADC_CHANNEL_CFG2_BASE); 267 writel(cfg1, info->regs + IMX7D_EACH_CHANNEL_REG_OFFSET * channel); 268 } 269 270 static u32 imx7d_adc_get_sample_rate(struct imx7d_adc *info) 271 { 272 u32 analogue_core_clk; 273 u32 core_time_unit = info->adc_feature.core_time_unit; 274 u32 tmp; 275 276 analogue_core_clk = IMX7D_ADC_INPUT_CLK / info->pre_div_num; 277 tmp = (core_time_unit + 1) * 6; 278 279 return analogue_core_clk / tmp; 280 } 281 282 static int imx7d_adc_read_raw(struct iio_dev *indio_dev, 283 struct iio_chan_spec const *chan, 284 int *val, 285 int *val2, 286 long mask) 287 { 288 struct imx7d_adc *info = iio_priv(indio_dev); 289 290 u32 channel; 291 long ret; 292 293 switch (mask) { 294 case IIO_CHAN_INFO_RAW: 295 mutex_lock(&indio_dev->mlock); 296 reinit_completion(&info->completion); 297 298 channel = chan->channel & 0x03; 299 info->channel = channel; 300 imx7d_adc_channel_set(info); 301 302 ret = wait_for_completion_interruptible_timeout 303 (&info->completion, IMX7D_ADC_TIMEOUT); 304 if (ret == 0) { 305 mutex_unlock(&indio_dev->mlock); 306 return -ETIMEDOUT; 307 } 308 if (ret < 0) { 309 mutex_unlock(&indio_dev->mlock); 310 return ret; 311 } 312 313 *val = info->value; 314 mutex_unlock(&indio_dev->mlock); 315 return IIO_VAL_INT; 316 317 case IIO_CHAN_INFO_SCALE: 318 info->vref_uv = regulator_get_voltage(info->vref); 319 *val = info->vref_uv / 1000; 320 *val2 = 12; 321 return IIO_VAL_FRACTIONAL_LOG2; 322 323 case IIO_CHAN_INFO_SAMP_FREQ: 324 *val = imx7d_adc_get_sample_rate(info); 325 return IIO_VAL_INT; 326 327 default: 328 return -EINVAL; 329 } 330 } 331 332 static int imx7d_adc_read_data(struct imx7d_adc *info) 333 { 334 u32 channel; 335 u32 value; 336 337 channel = info->channel & 0x03; 338 339 /* 340 * channel A and B conversion result share one register, 341 * bit[27~16] is the channel B conversion result, 342 * bit[11~0] is the channel A conversion result. 343 * channel C and D is the same. 344 */ 345 if (channel < 2) 346 value = readl(info->regs + IMX7D_REG_ADC_CHA_B_CNV_RSLT); 347 else 348 value = readl(info->regs + IMX7D_REG_ADC_CHC_D_CNV_RSLT); 349 if (channel & 0x1) /* channel B or D */ 350 value = (value >> 16) & 0xFFF; 351 else /* channel A or C */ 352 value &= 0xFFF; 353 354 return value; 355 } 356 357 static irqreturn_t imx7d_adc_isr(int irq, void *dev_id) 358 { 359 struct imx7d_adc *info = dev_id; 360 int status; 361 362 status = readl(info->regs + IMX7D_REG_ADC_INT_STATUS); 363 if (status & IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS) { 364 info->value = imx7d_adc_read_data(info); 365 complete(&info->completion); 366 367 /* 368 * The register IMX7D_REG_ADC_INT_STATUS can't clear 369 * itself after read operation, need software to write 370 * 0 to the related bit. Here we clear the channel A/B/C/D 371 * conversion finished flag. 372 */ 373 status &= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_INT_STATUS; 374 writel(status, info->regs + IMX7D_REG_ADC_INT_STATUS); 375 } 376 377 /* 378 * If the channel A/B/C/D conversion timeout, report it and clear these 379 * timeout flags. 380 */ 381 if (status & IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT) { 382 dev_err(info->dev, 383 "ADC got conversion time out interrupt: 0x%08x\n", 384 status); 385 status &= ~IMX7D_REG_ADC_INT_STATUS_CHANNEL_CONV_TIME_OUT; 386 writel(status, info->regs + IMX7D_REG_ADC_INT_STATUS); 387 } 388 389 return IRQ_HANDLED; 390 } 391 392 static int imx7d_adc_reg_access(struct iio_dev *indio_dev, 393 unsigned reg, unsigned writeval, 394 unsigned *readval) 395 { 396 struct imx7d_adc *info = iio_priv(indio_dev); 397 398 if (!readval || reg % 4 || reg > IMX7D_REG_ADC_ADC_CFG) 399 return -EINVAL; 400 401 *readval = readl(info->regs + reg); 402 403 return 0; 404 } 405 406 static const struct iio_info imx7d_adc_iio_info = { 407 .read_raw = &imx7d_adc_read_raw, 408 .debugfs_reg_access = &imx7d_adc_reg_access, 409 }; 410 411 static const struct of_device_id imx7d_adc_match[] = { 412 { .compatible = "fsl,imx7d-adc", }, 413 { /* sentinel */ } 414 }; 415 MODULE_DEVICE_TABLE(of, imx7d_adc_match); 416 417 static void imx7d_adc_power_down(struct imx7d_adc *info) 418 { 419 u32 adc_cfg; 420 421 adc_cfg = readl(info->regs + IMX7D_REG_ADC_ADC_CFG); 422 adc_cfg |= IMX7D_REG_ADC_ADC_CFG_ADC_CLK_DOWN | 423 IMX7D_REG_ADC_ADC_CFG_ADC_POWER_DOWN; 424 adc_cfg &= ~IMX7D_REG_ADC_ADC_CFG_ADC_EN; 425 writel(adc_cfg, info->regs + IMX7D_REG_ADC_ADC_CFG); 426 } 427 428 static int imx7d_adc_enable(struct device *dev) 429 { 430 struct iio_dev *indio_dev = dev_get_drvdata(dev); 431 struct imx7d_adc *info = iio_priv(indio_dev); 432 int ret; 433 434 ret = regulator_enable(info->vref); 435 if (ret) { 436 dev_err(info->dev, 437 "Can't enable adc reference top voltage, err = %d\n", 438 ret); 439 return ret; 440 } 441 442 ret = clk_prepare_enable(info->clk); 443 if (ret) { 444 dev_err(info->dev, 445 "Could not prepare or enable clock.\n"); 446 regulator_disable(info->vref); 447 return ret; 448 } 449 450 imx7d_adc_hw_init(info); 451 452 return 0; 453 } 454 455 static int imx7d_adc_disable(struct device *dev) 456 { 457 struct iio_dev *indio_dev = dev_get_drvdata(dev); 458 struct imx7d_adc *info = iio_priv(indio_dev); 459 460 imx7d_adc_power_down(info); 461 462 clk_disable_unprepare(info->clk); 463 regulator_disable(info->vref); 464 465 return 0; 466 } 467 468 static void __imx7d_adc_disable(void *data) 469 { 470 imx7d_adc_disable(data); 471 } 472 473 static int imx7d_adc_probe(struct platform_device *pdev) 474 { 475 struct imx7d_adc *info; 476 struct iio_dev *indio_dev; 477 struct device *dev = &pdev->dev; 478 int irq; 479 int ret; 480 481 indio_dev = devm_iio_device_alloc(dev, sizeof(*info)); 482 if (!indio_dev) { 483 dev_err(&pdev->dev, "Failed allocating iio device\n"); 484 return -ENOMEM; 485 } 486 487 info = iio_priv(indio_dev); 488 info->dev = dev; 489 490 info->regs = devm_platform_ioremap_resource(pdev, 0); 491 if (IS_ERR(info->regs)) 492 return PTR_ERR(info->regs); 493 494 irq = platform_get_irq(pdev, 0); 495 if (irq < 0) 496 return dev_err_probe(dev, irq, "Failed getting irq\n"); 497 498 info->clk = devm_clk_get(dev, "adc"); 499 if (IS_ERR(info->clk)) 500 return dev_err_probe(dev, PTR_ERR(info->clk), "Failed getting clock\n"); 501 502 info->vref = devm_regulator_get(dev, "vref"); 503 if (IS_ERR(info->vref)) 504 return dev_err_probe(dev, PTR_ERR(info->vref), 505 "Failed getting reference voltage\n"); 506 507 platform_set_drvdata(pdev, indio_dev); 508 509 init_completion(&info->completion); 510 511 indio_dev->name = dev_name(dev); 512 indio_dev->info = &imx7d_adc_iio_info; 513 indio_dev->modes = INDIO_DIRECT_MODE; 514 indio_dev->channels = imx7d_adc_iio_channels; 515 indio_dev->num_channels = ARRAY_SIZE(imx7d_adc_iio_channels); 516 517 ret = devm_request_irq(dev, irq, imx7d_adc_isr, 0, dev_name(dev), info); 518 if (ret < 0) { 519 dev_err(dev, "Failed requesting irq, irq = %d\n", irq); 520 return ret; 521 } 522 523 imx7d_adc_feature_config(info); 524 525 ret = imx7d_adc_enable(&indio_dev->dev); 526 if (ret) 527 return ret; 528 529 ret = devm_add_action_or_reset(dev, __imx7d_adc_disable, 530 &indio_dev->dev); 531 if (ret) 532 return ret; 533 534 ret = devm_iio_device_register(dev, indio_dev); 535 if (ret) { 536 dev_err(&pdev->dev, "Couldn't register the device.\n"); 537 return ret; 538 } 539 540 return 0; 541 } 542 543 static SIMPLE_DEV_PM_OPS(imx7d_adc_pm_ops, imx7d_adc_disable, imx7d_adc_enable); 544 545 static struct platform_driver imx7d_adc_driver = { 546 .probe = imx7d_adc_probe, 547 .driver = { 548 .name = "imx7d_adc", 549 .of_match_table = imx7d_adc_match, 550 .pm = &imx7d_adc_pm_ops, 551 }, 552 }; 553 554 module_platform_driver(imx7d_adc_driver); 555 556 MODULE_AUTHOR("Haibo Chen <haibo.chen@freescale.com>"); 557 MODULE_DESCRIPTION("Freescale IMX7D ADC driver"); 558 MODULE_LICENSE("GPL v2"); 559