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