1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Atmel ADC driver for SAMA5D2 devices and compatible. 4 * 5 * Copyright (C) 2015 Atmel, 6 * 2015 Ludovic Desroches <ludovic.desroches@atmel.com> 7 * 2021 Microchip Technology, Inc. and its subsidiaries 8 * 2021 Eugen Hristev <eugen.hristev@microchip.com> 9 */ 10 11 #include <linux/bitops.h> 12 #include <linux/clk.h> 13 #include <linux/delay.h> 14 #include <linux/dma-mapping.h> 15 #include <linux/dmaengine.h> 16 #include <linux/interrupt.h> 17 #include <linux/io.h> 18 #include <linux/module.h> 19 #include <linux/of_device.h> 20 #include <linux/platform_device.h> 21 #include <linux/sched.h> 22 #include <linux/wait.h> 23 #include <linux/iio/iio.h> 24 #include <linux/iio/sysfs.h> 25 #include <linux/iio/buffer.h> 26 #include <linux/iio/trigger.h> 27 #include <linux/iio/trigger_consumer.h> 28 #include <linux/iio/triggered_buffer.h> 29 #include <linux/pinctrl/consumer.h> 30 #include <linux/regulator/consumer.h> 31 32 struct at91_adc_reg_layout { 33 /* Control Register */ 34 u16 CR; 35 /* Software Reset */ 36 #define AT91_SAMA5D2_CR_SWRST BIT(0) 37 /* Start Conversion */ 38 #define AT91_SAMA5D2_CR_START BIT(1) 39 /* Touchscreen Calibration */ 40 #define AT91_SAMA5D2_CR_TSCALIB BIT(2) 41 /* Comparison Restart */ 42 #define AT91_SAMA5D2_CR_CMPRST BIT(4) 43 44 /* Mode Register */ 45 u16 MR; 46 /* Trigger Selection */ 47 #define AT91_SAMA5D2_MR_TRGSEL(v) ((v) << 1) 48 /* ADTRG */ 49 #define AT91_SAMA5D2_MR_TRGSEL_TRIG0 0 50 /* TIOA0 */ 51 #define AT91_SAMA5D2_MR_TRGSEL_TRIG1 1 52 /* TIOA1 */ 53 #define AT91_SAMA5D2_MR_TRGSEL_TRIG2 2 54 /* TIOA2 */ 55 #define AT91_SAMA5D2_MR_TRGSEL_TRIG3 3 56 /* PWM event line 0 */ 57 #define AT91_SAMA5D2_MR_TRGSEL_TRIG4 4 58 /* PWM event line 1 */ 59 #define AT91_SAMA5D2_MR_TRGSEL_TRIG5 5 60 /* TIOA3 */ 61 #define AT91_SAMA5D2_MR_TRGSEL_TRIG6 6 62 /* RTCOUT0 */ 63 #define AT91_SAMA5D2_MR_TRGSEL_TRIG7 7 64 /* Sleep Mode */ 65 #define AT91_SAMA5D2_MR_SLEEP BIT(5) 66 /* Fast Wake Up */ 67 #define AT91_SAMA5D2_MR_FWUP BIT(6) 68 /* Prescaler Rate Selection */ 69 #define AT91_SAMA5D2_MR_PRESCAL(v) ((v) << AT91_SAMA5D2_MR_PRESCAL_OFFSET) 70 #define AT91_SAMA5D2_MR_PRESCAL_OFFSET 8 71 #define AT91_SAMA5D2_MR_PRESCAL_MAX 0xff 72 #define AT91_SAMA5D2_MR_PRESCAL_MASK GENMASK(15, 8) 73 /* Startup Time */ 74 #define AT91_SAMA5D2_MR_STARTUP(v) ((v) << 16) 75 #define AT91_SAMA5D2_MR_STARTUP_MASK GENMASK(19, 16) 76 /* Analog Change */ 77 #define AT91_SAMA5D2_MR_ANACH BIT(23) 78 /* Tracking Time */ 79 #define AT91_SAMA5D2_MR_TRACKTIM(v) ((v) << 24) 80 #define AT91_SAMA5D2_MR_TRACKTIM_MAX 0xff 81 /* Transfer Time */ 82 #define AT91_SAMA5D2_MR_TRANSFER(v) ((v) << 28) 83 #define AT91_SAMA5D2_MR_TRANSFER_MAX 0x3 84 /* Use Sequence Enable */ 85 #define AT91_SAMA5D2_MR_USEQ BIT(31) 86 87 /* Channel Sequence Register 1 */ 88 u16 SEQR1; 89 /* Channel Sequence Register 2 */ 90 u16 SEQR2; 91 /* Channel Enable Register */ 92 u16 CHER; 93 /* Channel Disable Register */ 94 u16 CHDR; 95 /* Channel Status Register */ 96 u16 CHSR; 97 /* Last Converted Data Register */ 98 u16 LCDR; 99 /* Interrupt Enable Register */ 100 u16 IER; 101 /* Interrupt Enable Register - TS X measurement ready */ 102 #define AT91_SAMA5D2_IER_XRDY BIT(20) 103 /* Interrupt Enable Register - TS Y measurement ready */ 104 #define AT91_SAMA5D2_IER_YRDY BIT(21) 105 /* Interrupt Enable Register - TS pressure measurement ready */ 106 #define AT91_SAMA5D2_IER_PRDY BIT(22) 107 /* Interrupt Enable Register - Data ready */ 108 #define AT91_SAMA5D2_IER_DRDY BIT(24) 109 /* Interrupt Enable Register - general overrun error */ 110 #define AT91_SAMA5D2_IER_GOVRE BIT(25) 111 /* Interrupt Enable Register - Pen detect */ 112 #define AT91_SAMA5D2_IER_PEN BIT(29) 113 /* Interrupt Enable Register - No pen detect */ 114 #define AT91_SAMA5D2_IER_NOPEN BIT(30) 115 116 /* Interrupt Disable Register */ 117 u16 IDR; 118 /* Interrupt Mask Register */ 119 u16 IMR; 120 /* Interrupt Status Register */ 121 u16 ISR; 122 /* End of Conversion Interrupt Enable Register */ 123 u16 EOC_IER; 124 /* End of Conversion Interrupt Disable Register */ 125 u16 EOC_IDR; 126 /* End of Conversion Interrupt Mask Register */ 127 u16 EOC_IMR; 128 /* End of Conversion Interrupt Status Register */ 129 u16 EOC_ISR; 130 /* Interrupt Status Register - Pen touching sense status */ 131 #define AT91_SAMA5D2_ISR_PENS BIT(31) 132 /* Last Channel Trigger Mode Register */ 133 u16 LCTMR; 134 /* Last Channel Compare Window Register */ 135 u16 LCCWR; 136 /* Overrun Status Register */ 137 u16 OVER; 138 /* Extended Mode Register */ 139 u16 EMR; 140 /* Extended Mode Register - Oversampling rate */ 141 #define AT91_SAMA5D2_EMR_OSR(V) ((V) << 16) 142 #define AT91_SAMA5D2_EMR_OSR_MASK GENMASK(17, 16) 143 #define AT91_SAMA5D2_EMR_OSR_1SAMPLES 0 144 #define AT91_SAMA5D2_EMR_OSR_4SAMPLES 1 145 #define AT91_SAMA5D2_EMR_OSR_16SAMPLES 2 146 147 /* Extended Mode Register - Averaging on single trigger event */ 148 #define AT91_SAMA5D2_EMR_ASTE(V) ((V) << 20) 149 150 /* Compare Window Register */ 151 u16 CWR; 152 /* Channel Gain Register */ 153 u16 CGR; 154 /* Channel Offset Register */ 155 u16 COR; 156 /* Channel Offset Register differential offset - constant, not a register */ 157 u16 COR_diff_offset; 158 /* Analog Control Register */ 159 u16 ACR; 160 /* Analog Control Register - Pen detect sensitivity mask */ 161 #define AT91_SAMA5D2_ACR_PENDETSENS_MASK GENMASK(1, 0) 162 163 /* Touchscreen Mode Register */ 164 u16 TSMR; 165 /* Touchscreen Mode Register - No touch mode */ 166 #define AT91_SAMA5D2_TSMR_TSMODE_NONE 0 167 /* Touchscreen Mode Register - 4 wire screen, no pressure measurement */ 168 #define AT91_SAMA5D2_TSMR_TSMODE_4WIRE_NO_PRESS 1 169 /* Touchscreen Mode Register - 4 wire screen, pressure measurement */ 170 #define AT91_SAMA5D2_TSMR_TSMODE_4WIRE_PRESS 2 171 /* Touchscreen Mode Register - 5 wire screen */ 172 #define AT91_SAMA5D2_TSMR_TSMODE_5WIRE 3 173 /* Touchscreen Mode Register - Average samples mask */ 174 #define AT91_SAMA5D2_TSMR_TSAV_MASK GENMASK(5, 4) 175 /* Touchscreen Mode Register - Average samples */ 176 #define AT91_SAMA5D2_TSMR_TSAV(x) ((x) << 4) 177 /* Touchscreen Mode Register - Touch/trigger frequency ratio mask */ 178 #define AT91_SAMA5D2_TSMR_TSFREQ_MASK GENMASK(11, 8) 179 /* Touchscreen Mode Register - Touch/trigger frequency ratio */ 180 #define AT91_SAMA5D2_TSMR_TSFREQ(x) ((x) << 8) 181 /* Touchscreen Mode Register - Pen Debounce Time mask */ 182 #define AT91_SAMA5D2_TSMR_PENDBC_MASK GENMASK(31, 28) 183 /* Touchscreen Mode Register - Pen Debounce Time */ 184 #define AT91_SAMA5D2_TSMR_PENDBC(x) ((x) << 28) 185 /* Touchscreen Mode Register - No DMA for touch measurements */ 186 #define AT91_SAMA5D2_TSMR_NOTSDMA BIT(22) 187 /* Touchscreen Mode Register - Disable pen detection */ 188 #define AT91_SAMA5D2_TSMR_PENDET_DIS (0 << 24) 189 /* Touchscreen Mode Register - Enable pen detection */ 190 #define AT91_SAMA5D2_TSMR_PENDET_ENA BIT(24) 191 192 /* Touchscreen X Position Register */ 193 u16 XPOSR; 194 /* Touchscreen Y Position Register */ 195 u16 YPOSR; 196 /* Touchscreen Pressure Register */ 197 u16 PRESSR; 198 /* Trigger Register */ 199 u16 TRGR; 200 /* Mask for TRGMOD field of TRGR register */ 201 #define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0) 202 /* No trigger, only software trigger can start conversions */ 203 #define AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER 0 204 /* Trigger Mode external trigger rising edge */ 205 #define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE 1 206 /* Trigger Mode external trigger falling edge */ 207 #define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL 2 208 /* Trigger Mode external trigger any edge */ 209 #define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY 3 210 /* Trigger Mode internal periodic */ 211 #define AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC 5 212 /* Trigger Mode - trigger period mask */ 213 #define AT91_SAMA5D2_TRGR_TRGPER_MASK GENMASK(31, 16) 214 /* Trigger Mode - trigger period */ 215 #define AT91_SAMA5D2_TRGR_TRGPER(x) ((x) << 16) 216 217 /* Correction Select Register */ 218 u16 COSR; 219 /* Correction Value Register */ 220 u16 CVR; 221 /* Channel Error Correction Register */ 222 u16 CECR; 223 /* Write Protection Mode Register */ 224 u16 WPMR; 225 /* Write Protection Status Register */ 226 u16 WPSR; 227 /* Version Register */ 228 u16 VERSION; 229 }; 230 231 static const struct at91_adc_reg_layout sama5d2_layout = { 232 .CR = 0x00, 233 .MR = 0x04, 234 .SEQR1 = 0x08, 235 .SEQR2 = 0x0c, 236 .CHER = 0x10, 237 .CHDR = 0x14, 238 .CHSR = 0x18, 239 .LCDR = 0x20, 240 .IER = 0x24, 241 .IDR = 0x28, 242 .IMR = 0x2c, 243 .ISR = 0x30, 244 .LCTMR = 0x34, 245 .LCCWR = 0x38, 246 .OVER = 0x3c, 247 .EMR = 0x40, 248 .CWR = 0x44, 249 .CGR = 0x48, 250 .COR = 0x4c, 251 .COR_diff_offset = 16, 252 .ACR = 0x94, 253 .TSMR = 0xb0, 254 .XPOSR = 0xb4, 255 .YPOSR = 0xb8, 256 .PRESSR = 0xbc, 257 .TRGR = 0xc0, 258 .COSR = 0xd0, 259 .CVR = 0xd4, 260 .CECR = 0xd8, 261 .WPMR = 0xe4, 262 .WPSR = 0xe8, 263 .VERSION = 0xfc, 264 }; 265 266 static const struct at91_adc_reg_layout sama7g5_layout = { 267 .CR = 0x00, 268 .MR = 0x04, 269 .SEQR1 = 0x08, 270 .SEQR2 = 0x0c, 271 .CHER = 0x10, 272 .CHDR = 0x14, 273 .CHSR = 0x18, 274 .LCDR = 0x20, 275 .IER = 0x24, 276 .IDR = 0x28, 277 .IMR = 0x2c, 278 .ISR = 0x30, 279 .EOC_IER = 0x34, 280 .EOC_IDR = 0x38, 281 .EOC_IMR = 0x3c, 282 .EOC_ISR = 0x40, 283 .OVER = 0x4c, 284 .EMR = 0x50, 285 .CWR = 0x54, 286 .COR = 0x5c, 287 .COR_diff_offset = 0, 288 .ACR = 0xe0, 289 .TRGR = 0x100, 290 .COSR = 0x104, 291 .CVR = 0x108, 292 .CECR = 0x10c, 293 .WPMR = 0x118, 294 .WPSR = 0x11c, 295 .VERSION = 0x130, 296 }; 297 298 #define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US 2000 /* 2ms */ 299 #define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US 200 300 301 #define AT91_SAMA5D2_XYZ_MASK GENMASK(11, 0) 302 303 #define AT91_SAMA5D2_MAX_POS_BITS 12 304 305 #define AT91_HWFIFO_MAX_SIZE_STR "128" 306 #define AT91_HWFIFO_MAX_SIZE 128 307 308 /* Possible values for oversampling ratio */ 309 #define AT91_OSR_1SAMPLES 1 310 #define AT91_OSR_4SAMPLES 4 311 #define AT91_OSR_16SAMPLES 16 312 313 #define AT91_SAMA5D2_CHAN_SINGLE(index, num, addr) \ 314 { \ 315 .type = IIO_VOLTAGE, \ 316 .channel = num, \ 317 .address = addr, \ 318 .scan_index = index, \ 319 .scan_type = { \ 320 .sign = 'u', \ 321 .realbits = 14, \ 322 .storagebits = 16, \ 323 }, \ 324 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 325 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 326 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\ 327 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ 328 .datasheet_name = "CH"#num, \ 329 .indexed = 1, \ 330 } 331 332 #define AT91_SAMA5D2_CHAN_DIFF(index, num, num2, addr) \ 333 { \ 334 .type = IIO_VOLTAGE, \ 335 .differential = 1, \ 336 .channel = num, \ 337 .channel2 = num2, \ 338 .address = addr, \ 339 .scan_index = index, \ 340 .scan_type = { \ 341 .sign = 's', \ 342 .realbits = 14, \ 343 .storagebits = 16, \ 344 }, \ 345 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 346 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 347 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\ 348 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ 349 .datasheet_name = "CH"#num"-CH"#num2, \ 350 .indexed = 1, \ 351 } 352 353 #define AT91_SAMA5D2_CHAN_TOUCH(num, name, mod) \ 354 { \ 355 .type = IIO_POSITIONRELATIVE, \ 356 .modified = 1, \ 357 .channel = num, \ 358 .channel2 = mod, \ 359 .scan_index = num, \ 360 .scan_type = { \ 361 .sign = 'u', \ 362 .realbits = 12, \ 363 .storagebits = 16, \ 364 }, \ 365 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 366 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\ 367 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ 368 .datasheet_name = name, \ 369 } 370 #define AT91_SAMA5D2_CHAN_PRESSURE(num, name) \ 371 { \ 372 .type = IIO_PRESSURE, \ 373 .channel = num, \ 374 .scan_index = num, \ 375 .scan_type = { \ 376 .sign = 'u', \ 377 .realbits = 12, \ 378 .storagebits = 16, \ 379 }, \ 380 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 381 .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\ 382 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), \ 383 .datasheet_name = name, \ 384 } 385 386 #define at91_adc_readl(st, reg) \ 387 readl_relaxed((st)->base + (st)->soc_info.platform->layout->reg) 388 #define at91_adc_read_chan(st, reg) \ 389 readl_relaxed((st)->base + reg) 390 #define at91_adc_writel(st, reg, val) \ 391 writel_relaxed(val, (st)->base + (st)->soc_info.platform->layout->reg) 392 393 /** 394 * struct at91_adc_platform - at91-sama5d2 platform information struct 395 * @layout: pointer to the reg layout struct 396 * @adc_channels: pointer to an array of channels for registering in 397 * the iio subsystem 398 * @nr_channels: number of physical channels available 399 * @touch_chan_x: index of the touchscreen X channel 400 * @touch_chan_y: index of the touchscreen Y channel 401 * @touch_chan_p: index of the touchscreen P channel 402 * @max_channels: number of total channels 403 * @max_index: highest channel index (highest index may be higher 404 * than the total channel number) 405 * @hw_trig_cnt: number of possible hardware triggers 406 */ 407 struct at91_adc_platform { 408 const struct at91_adc_reg_layout *layout; 409 const struct iio_chan_spec (*adc_channels)[]; 410 unsigned int nr_channels; 411 unsigned int touch_chan_x; 412 unsigned int touch_chan_y; 413 unsigned int touch_chan_p; 414 unsigned int max_channels; 415 unsigned int max_index; 416 unsigned int hw_trig_cnt; 417 }; 418 419 /** 420 * struct at91_adc_soc_info - at91-sama5d2 soc information struct 421 * @startup_time: device startup time 422 * @min_sample_rate: minimum sample rate in Hz 423 * @max_sample_rate: maximum sample rate in Hz 424 * @platform: pointer to the platform structure 425 */ 426 struct at91_adc_soc_info { 427 unsigned startup_time; 428 unsigned min_sample_rate; 429 unsigned max_sample_rate; 430 const struct at91_adc_platform *platform; 431 }; 432 433 struct at91_adc_trigger { 434 char *name; 435 unsigned int trgmod_value; 436 unsigned int edge_type; 437 bool hw_trig; 438 }; 439 440 /** 441 * struct at91_adc_dma - at91-sama5d2 dma information struct 442 * @dma_chan: the dma channel acquired 443 * @rx_buf: dma coherent allocated area 444 * @rx_dma_buf: dma handler for the buffer 445 * @phys_addr: physical address of the ADC base register 446 * @buf_idx: index inside the dma buffer where reading was last done 447 * @rx_buf_sz: size of buffer used by DMA operation 448 * @watermark: number of conversions to copy before DMA triggers irq 449 * @dma_ts: hold the start timestamp of dma operation 450 */ 451 struct at91_adc_dma { 452 struct dma_chan *dma_chan; 453 u8 *rx_buf; 454 dma_addr_t rx_dma_buf; 455 phys_addr_t phys_addr; 456 int buf_idx; 457 int rx_buf_sz; 458 int watermark; 459 s64 dma_ts; 460 }; 461 462 /** 463 * struct at91_adc_touch - at91-sama5d2 touchscreen information struct 464 * @sample_period_val: the value for periodic trigger interval 465 * @touching: is the pen touching the screen or not 466 * @x_pos: temporary placeholder for pressure computation 467 * @channels_bitmask: bitmask with the touchscreen channels enabled 468 * @workq: workqueue for buffer data pushing 469 */ 470 struct at91_adc_touch { 471 u16 sample_period_val; 472 bool touching; 473 u16 x_pos; 474 unsigned long channels_bitmask; 475 struct work_struct workq; 476 }; 477 478 /* 479 * Buffer size requirements: 480 * No channels * bytes_per_channel(2) + timestamp bytes (8) 481 * Divided by 2 because we need half words. 482 * We assume 32 channels for now, has to be increased if needed. 483 * Nobody minds a buffer being too big. 484 */ 485 #define AT91_BUFFER_MAX_HWORDS ((32 * 2 + 8) / 2) 486 487 struct at91_adc_state { 488 void __iomem *base; 489 int irq; 490 struct clk *per_clk; 491 struct regulator *reg; 492 struct regulator *vref; 493 int vref_uv; 494 unsigned int current_sample_rate; 495 struct iio_trigger *trig; 496 const struct at91_adc_trigger *selected_trig; 497 const struct iio_chan_spec *chan; 498 bool conversion_done; 499 u32 conversion_value; 500 unsigned int oversampling_ratio; 501 struct at91_adc_soc_info soc_info; 502 wait_queue_head_t wq_data_available; 503 struct at91_adc_dma dma_st; 504 struct at91_adc_touch touch_st; 505 struct iio_dev *indio_dev; 506 /* Ensure naturally aligned timestamp */ 507 u16 buffer[AT91_BUFFER_MAX_HWORDS] __aligned(8); 508 /* 509 * lock to prevent concurrent 'single conversion' requests through 510 * sysfs. 511 */ 512 struct mutex lock; 513 }; 514 515 static const struct at91_adc_trigger at91_adc_trigger_list[] = { 516 { 517 .name = "external_rising", 518 .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE, 519 .edge_type = IRQ_TYPE_EDGE_RISING, 520 .hw_trig = true, 521 }, 522 { 523 .name = "external_falling", 524 .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL, 525 .edge_type = IRQ_TYPE_EDGE_FALLING, 526 .hw_trig = true, 527 }, 528 { 529 .name = "external_any", 530 .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY, 531 .edge_type = IRQ_TYPE_EDGE_BOTH, 532 .hw_trig = true, 533 }, 534 { 535 .name = "software", 536 .trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER, 537 .edge_type = IRQ_TYPE_NONE, 538 .hw_trig = false, 539 }, 540 }; 541 542 static const struct iio_chan_spec at91_sama5d2_adc_channels[] = { 543 AT91_SAMA5D2_CHAN_SINGLE(0, 0, 0x50), 544 AT91_SAMA5D2_CHAN_SINGLE(1, 1, 0x54), 545 AT91_SAMA5D2_CHAN_SINGLE(2, 2, 0x58), 546 AT91_SAMA5D2_CHAN_SINGLE(3, 3, 0x5c), 547 AT91_SAMA5D2_CHAN_SINGLE(4, 4, 0x60), 548 AT91_SAMA5D2_CHAN_SINGLE(5, 5, 0x64), 549 AT91_SAMA5D2_CHAN_SINGLE(6, 6, 0x68), 550 AT91_SAMA5D2_CHAN_SINGLE(7, 7, 0x6c), 551 AT91_SAMA5D2_CHAN_SINGLE(8, 8, 0x70), 552 AT91_SAMA5D2_CHAN_SINGLE(9, 9, 0x74), 553 AT91_SAMA5D2_CHAN_SINGLE(10, 10, 0x78), 554 AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x7c), 555 /* original ABI has the differential channels with a gap in between */ 556 AT91_SAMA5D2_CHAN_DIFF(12, 0, 1, 0x50), 557 AT91_SAMA5D2_CHAN_DIFF(14, 2, 3, 0x58), 558 AT91_SAMA5D2_CHAN_DIFF(16, 4, 5, 0x60), 559 AT91_SAMA5D2_CHAN_DIFF(18, 6, 7, 0x68), 560 AT91_SAMA5D2_CHAN_DIFF(20, 8, 9, 0x70), 561 AT91_SAMA5D2_CHAN_DIFF(22, 10, 11, 0x78), 562 IIO_CHAN_SOFT_TIMESTAMP(23), 563 AT91_SAMA5D2_CHAN_TOUCH(24, "x", IIO_MOD_X), 564 AT91_SAMA5D2_CHAN_TOUCH(25, "y", IIO_MOD_Y), 565 AT91_SAMA5D2_CHAN_PRESSURE(26, "pressure"), 566 }; 567 568 static const struct iio_chan_spec at91_sama7g5_adc_channels[] = { 569 AT91_SAMA5D2_CHAN_SINGLE(0, 0, 0x60), 570 AT91_SAMA5D2_CHAN_SINGLE(1, 1, 0x64), 571 AT91_SAMA5D2_CHAN_SINGLE(2, 2, 0x68), 572 AT91_SAMA5D2_CHAN_SINGLE(3, 3, 0x6c), 573 AT91_SAMA5D2_CHAN_SINGLE(4, 4, 0x70), 574 AT91_SAMA5D2_CHAN_SINGLE(5, 5, 0x74), 575 AT91_SAMA5D2_CHAN_SINGLE(6, 6, 0x78), 576 AT91_SAMA5D2_CHAN_SINGLE(7, 7, 0x7c), 577 AT91_SAMA5D2_CHAN_SINGLE(8, 8, 0x80), 578 AT91_SAMA5D2_CHAN_SINGLE(9, 9, 0x84), 579 AT91_SAMA5D2_CHAN_SINGLE(10, 10, 0x88), 580 AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x8c), 581 AT91_SAMA5D2_CHAN_SINGLE(12, 12, 0x90), 582 AT91_SAMA5D2_CHAN_SINGLE(13, 13, 0x94), 583 AT91_SAMA5D2_CHAN_SINGLE(14, 14, 0x98), 584 AT91_SAMA5D2_CHAN_SINGLE(15, 15, 0x9c), 585 AT91_SAMA5D2_CHAN_DIFF(16, 0, 1, 0x60), 586 AT91_SAMA5D2_CHAN_DIFF(17, 2, 3, 0x68), 587 AT91_SAMA5D2_CHAN_DIFF(18, 4, 5, 0x70), 588 AT91_SAMA5D2_CHAN_DIFF(19, 6, 7, 0x78), 589 AT91_SAMA5D2_CHAN_DIFF(20, 8, 9, 0x80), 590 AT91_SAMA5D2_CHAN_DIFF(21, 10, 11, 0x88), 591 AT91_SAMA5D2_CHAN_DIFF(22, 12, 13, 0x90), 592 AT91_SAMA5D2_CHAN_DIFF(23, 14, 15, 0x98), 593 IIO_CHAN_SOFT_TIMESTAMP(24), 594 }; 595 596 static const struct at91_adc_platform sama5d2_platform = { 597 .layout = &sama5d2_layout, 598 .adc_channels = &at91_sama5d2_adc_channels, 599 #define AT91_SAMA5D2_SINGLE_CHAN_CNT 12 600 #define AT91_SAMA5D2_DIFF_CHAN_CNT 6 601 .nr_channels = AT91_SAMA5D2_SINGLE_CHAN_CNT + 602 AT91_SAMA5D2_DIFF_CHAN_CNT, 603 #define AT91_SAMA5D2_TOUCH_X_CHAN_IDX (AT91_SAMA5D2_SINGLE_CHAN_CNT + \ 604 AT91_SAMA5D2_DIFF_CHAN_CNT * 2) 605 .touch_chan_x = AT91_SAMA5D2_TOUCH_X_CHAN_IDX, 606 #define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX (AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1) 607 .touch_chan_y = AT91_SAMA5D2_TOUCH_Y_CHAN_IDX, 608 #define AT91_SAMA5D2_TOUCH_P_CHAN_IDX (AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1) 609 .touch_chan_p = AT91_SAMA5D2_TOUCH_P_CHAN_IDX, 610 #define AT91_SAMA5D2_MAX_CHAN_IDX AT91_SAMA5D2_TOUCH_P_CHAN_IDX 611 .max_channels = ARRAY_SIZE(at91_sama5d2_adc_channels), 612 .max_index = AT91_SAMA5D2_MAX_CHAN_IDX, 613 #define AT91_SAMA5D2_HW_TRIG_CNT 3 614 .hw_trig_cnt = AT91_SAMA5D2_HW_TRIG_CNT, 615 }; 616 617 static const struct at91_adc_platform sama7g5_platform = { 618 .layout = &sama7g5_layout, 619 .adc_channels = &at91_sama7g5_adc_channels, 620 #define AT91_SAMA7G5_SINGLE_CHAN_CNT 16 621 #define AT91_SAMA7G5_DIFF_CHAN_CNT 8 622 .nr_channels = AT91_SAMA7G5_SINGLE_CHAN_CNT + 623 AT91_SAMA7G5_DIFF_CHAN_CNT, 624 #define AT91_SAMA7G5_MAX_CHAN_IDX (AT91_SAMA7G5_SINGLE_CHAN_CNT + \ 625 AT91_SAMA7G5_DIFF_CHAN_CNT) 626 .max_channels = ARRAY_SIZE(at91_sama7g5_adc_channels), 627 .max_index = AT91_SAMA7G5_MAX_CHAN_IDX, 628 #define AT91_SAMA7G5_HW_TRIG_CNT 3 629 .hw_trig_cnt = AT91_SAMA7G5_HW_TRIG_CNT, 630 }; 631 632 static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan) 633 { 634 int i; 635 636 for (i = 0; i < indio_dev->num_channels; i++) { 637 if (indio_dev->channels[i].scan_index == chan) 638 return i; 639 } 640 return -EINVAL; 641 } 642 643 static inline struct iio_chan_spec const * 644 at91_adc_chan_get(struct iio_dev *indio_dev, int chan) 645 { 646 int index = at91_adc_chan_xlate(indio_dev, chan); 647 648 if (index < 0) 649 return NULL; 650 return indio_dev->channels + index; 651 } 652 653 static inline int at91_adc_of_xlate(struct iio_dev *indio_dev, 654 const struct of_phandle_args *iiospec) 655 { 656 return at91_adc_chan_xlate(indio_dev, iiospec->args[0]); 657 } 658 659 static unsigned int at91_adc_active_scan_mask_to_reg(struct iio_dev *indio_dev) 660 { 661 u32 mask = 0; 662 u8 bit; 663 struct at91_adc_state *st = iio_priv(indio_dev); 664 665 for_each_set_bit(bit, indio_dev->active_scan_mask, 666 indio_dev->num_channels) { 667 struct iio_chan_spec const *chan = 668 at91_adc_chan_get(indio_dev, bit); 669 mask |= BIT(chan->channel); 670 } 671 672 return mask & GENMASK(st->soc_info.platform->nr_channels, 0); 673 } 674 675 static void at91_adc_cor(struct at91_adc_state *st, 676 struct iio_chan_spec const *chan) 677 { 678 u32 cor, cur_cor; 679 680 cor = BIT(chan->channel) | BIT(chan->channel2); 681 682 cur_cor = at91_adc_readl(st, COR); 683 cor <<= st->soc_info.platform->layout->COR_diff_offset; 684 if (chan->differential) 685 at91_adc_writel(st, COR, cur_cor | cor); 686 else 687 at91_adc_writel(st, COR, cur_cor & ~cor); 688 } 689 690 static void at91_adc_irq_status(struct at91_adc_state *st, u32 *status, 691 u32 *eoc) 692 { 693 *status = at91_adc_readl(st, ISR); 694 if (st->soc_info.platform->layout->EOC_ISR) 695 *eoc = at91_adc_readl(st, EOC_ISR); 696 else 697 *eoc = *status; 698 } 699 700 static void at91_adc_irq_mask(struct at91_adc_state *st, u32 *status, u32 *eoc) 701 { 702 *status = at91_adc_readl(st, IMR); 703 if (st->soc_info.platform->layout->EOC_IMR) 704 *eoc = at91_adc_readl(st, EOC_IMR); 705 else 706 *eoc = *status; 707 } 708 709 static void at91_adc_eoc_dis(struct at91_adc_state *st, unsigned int channel) 710 { 711 /* 712 * On some products having the EOC bits in a separate register, 713 * errata recommends not writing this register (EOC_IDR). 714 * On products having the EOC bits in the IDR register, it's fine to write it. 715 */ 716 if (!st->soc_info.platform->layout->EOC_IDR) 717 at91_adc_writel(st, IDR, BIT(channel)); 718 } 719 720 static void at91_adc_eoc_ena(struct at91_adc_state *st, unsigned int channel) 721 { 722 if (!st->soc_info.platform->layout->EOC_IDR) 723 at91_adc_writel(st, IER, BIT(channel)); 724 else 725 at91_adc_writel(st, EOC_IER, BIT(channel)); 726 } 727 728 static void at91_adc_config_emr(struct at91_adc_state *st) 729 { 730 /* configure the extended mode register */ 731 unsigned int emr = at91_adc_readl(st, EMR); 732 733 /* select oversampling per single trigger event */ 734 emr |= AT91_SAMA5D2_EMR_ASTE(1); 735 736 /* delete leftover content if it's the case */ 737 emr &= ~AT91_SAMA5D2_EMR_OSR_MASK; 738 739 /* select oversampling ratio from configuration */ 740 switch (st->oversampling_ratio) { 741 case AT91_OSR_1SAMPLES: 742 emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_1SAMPLES) & 743 AT91_SAMA5D2_EMR_OSR_MASK; 744 break; 745 case AT91_OSR_4SAMPLES: 746 emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_4SAMPLES) & 747 AT91_SAMA5D2_EMR_OSR_MASK; 748 break; 749 case AT91_OSR_16SAMPLES: 750 emr |= AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_16SAMPLES) & 751 AT91_SAMA5D2_EMR_OSR_MASK; 752 break; 753 } 754 755 at91_adc_writel(st, EMR, emr); 756 } 757 758 static int at91_adc_adjust_val_osr(struct at91_adc_state *st, int *val) 759 { 760 if (st->oversampling_ratio == AT91_OSR_1SAMPLES) { 761 /* 762 * in this case we only have 12 bits of real data, but channel 763 * is registered as 14 bits, so shift left two bits 764 */ 765 *val <<= 2; 766 } else if (st->oversampling_ratio == AT91_OSR_4SAMPLES) { 767 /* 768 * in this case we have 13 bits of real data, but channel 769 * is registered as 14 bits, so left shift one bit 770 */ 771 *val <<= 1; 772 } 773 774 return IIO_VAL_INT; 775 } 776 777 static void at91_adc_adjust_val_osr_array(struct at91_adc_state *st, void *buf, 778 int len) 779 { 780 int i = 0, val; 781 u16 *buf_u16 = (u16 *) buf; 782 783 /* 784 * We are converting each two bytes (each sample). 785 * First convert the byte based array to u16, and convert each sample 786 * separately. 787 * Each value is two bytes in an array of chars, so to not shift 788 * more than we need, save the value separately. 789 * len is in bytes, so divide by two to get number of samples. 790 */ 791 while (i < len / 2) { 792 val = buf_u16[i]; 793 at91_adc_adjust_val_osr(st, &val); 794 buf_u16[i] = val; 795 i++; 796 } 797 } 798 799 static int at91_adc_configure_touch(struct at91_adc_state *st, bool state) 800 { 801 u32 clk_khz = st->current_sample_rate / 1000; 802 int i = 0; 803 u16 pendbc; 804 u32 tsmr, acr; 805 806 if (!state) { 807 /* disabling touch IRQs and setting mode to no touch enabled */ 808 at91_adc_writel(st, IDR, 809 AT91_SAMA5D2_IER_PEN | AT91_SAMA5D2_IER_NOPEN); 810 at91_adc_writel(st, TSMR, 0); 811 return 0; 812 } 813 /* 814 * debounce time is in microseconds, we need it in milliseconds to 815 * multiply with kilohertz, so, divide by 1000, but after the multiply. 816 * round up to make sure pendbc is at least 1 817 */ 818 pendbc = round_up(AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US * 819 clk_khz / 1000, 1); 820 821 /* get the required exponent */ 822 while (pendbc >> i++) 823 ; 824 825 pendbc = i; 826 827 tsmr = AT91_SAMA5D2_TSMR_TSMODE_4WIRE_PRESS; 828 829 tsmr |= AT91_SAMA5D2_TSMR_TSAV(2) & AT91_SAMA5D2_TSMR_TSAV_MASK; 830 tsmr |= AT91_SAMA5D2_TSMR_PENDBC(pendbc) & 831 AT91_SAMA5D2_TSMR_PENDBC_MASK; 832 tsmr |= AT91_SAMA5D2_TSMR_NOTSDMA; 833 tsmr |= AT91_SAMA5D2_TSMR_PENDET_ENA; 834 tsmr |= AT91_SAMA5D2_TSMR_TSFREQ(2) & AT91_SAMA5D2_TSMR_TSFREQ_MASK; 835 836 at91_adc_writel(st, TSMR, tsmr); 837 838 acr = at91_adc_readl(st, ACR); 839 acr &= ~AT91_SAMA5D2_ACR_PENDETSENS_MASK; 840 acr |= 0x02 & AT91_SAMA5D2_ACR_PENDETSENS_MASK; 841 at91_adc_writel(st, ACR, acr); 842 843 /* Sample Period Time = (TRGPER + 1) / ADCClock */ 844 st->touch_st.sample_period_val = 845 round_up((AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US * 846 clk_khz / 1000) - 1, 1); 847 /* enable pen detect IRQ */ 848 at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN); 849 850 return 0; 851 } 852 853 static u16 at91_adc_touch_pos(struct at91_adc_state *st, int reg) 854 { 855 u32 val = 0; 856 u32 scale, result, pos; 857 858 /* 859 * to obtain the actual position we must divide by scale 860 * and multiply with max, where 861 * max = 2^AT91_SAMA5D2_MAX_POS_BITS - 1 862 */ 863 /* first half of register is the x or y, second half is the scale */ 864 if (reg == st->soc_info.platform->layout->XPOSR) 865 val = at91_adc_readl(st, XPOSR); 866 else if (reg == st->soc_info.platform->layout->YPOSR) 867 val = at91_adc_readl(st, YPOSR); 868 869 if (!val) 870 dev_dbg(&st->indio_dev->dev, "pos is 0\n"); 871 872 pos = val & AT91_SAMA5D2_XYZ_MASK; 873 result = (pos << AT91_SAMA5D2_MAX_POS_BITS) - pos; 874 scale = (val >> 16) & AT91_SAMA5D2_XYZ_MASK; 875 if (scale == 0) { 876 dev_err(&st->indio_dev->dev, "scale is 0\n"); 877 return 0; 878 } 879 result /= scale; 880 881 return result; 882 } 883 884 static u16 at91_adc_touch_x_pos(struct at91_adc_state *st) 885 { 886 st->touch_st.x_pos = at91_adc_touch_pos(st, st->soc_info.platform->layout->XPOSR); 887 return st->touch_st.x_pos; 888 } 889 890 static u16 at91_adc_touch_y_pos(struct at91_adc_state *st) 891 { 892 return at91_adc_touch_pos(st, st->soc_info.platform->layout->YPOSR); 893 } 894 895 static u16 at91_adc_touch_pressure(struct at91_adc_state *st) 896 { 897 u32 val; 898 u32 z1, z2; 899 u32 pres; 900 u32 rxp = 1; 901 u32 factor = 1000; 902 903 /* calculate the pressure */ 904 val = at91_adc_readl(st, PRESSR); 905 z1 = val & AT91_SAMA5D2_XYZ_MASK; 906 z2 = (val >> 16) & AT91_SAMA5D2_XYZ_MASK; 907 908 if (z1 != 0) 909 pres = rxp * (st->touch_st.x_pos * factor / 1024) * 910 (z2 * factor / z1 - factor) / 911 factor; 912 else 913 pres = 0xFFFF; /* no pen contact */ 914 915 /* 916 * The pressure from device grows down, minimum is 0xFFFF, maximum 0x0. 917 * We compute it this way, but let's return it in the expected way, 918 * growing from 0 to 0xFFFF. 919 */ 920 return 0xFFFF - pres; 921 } 922 923 static int at91_adc_read_position(struct at91_adc_state *st, int chan, u16 *val) 924 { 925 *val = 0; 926 if (!st->touch_st.touching) 927 return -ENODATA; 928 if (chan == st->soc_info.platform->touch_chan_x) 929 *val = at91_adc_touch_x_pos(st); 930 else if (chan == st->soc_info.platform->touch_chan_y) 931 *val = at91_adc_touch_y_pos(st); 932 else 933 return -ENODATA; 934 935 return IIO_VAL_INT; 936 } 937 938 static int at91_adc_read_pressure(struct at91_adc_state *st, int chan, u16 *val) 939 { 940 *val = 0; 941 if (!st->touch_st.touching) 942 return -ENODATA; 943 if (chan == st->soc_info.platform->touch_chan_p) 944 *val = at91_adc_touch_pressure(st); 945 else 946 return -ENODATA; 947 948 return IIO_VAL_INT; 949 } 950 951 static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state) 952 { 953 struct iio_dev *indio = iio_trigger_get_drvdata(trig); 954 struct at91_adc_state *st = iio_priv(indio); 955 u32 status = at91_adc_readl(st, TRGR); 956 957 /* clear TRGMOD */ 958 status &= ~AT91_SAMA5D2_TRGR_TRGMOD_MASK; 959 960 if (state) 961 status |= st->selected_trig->trgmod_value; 962 963 /* set/unset hw trigger */ 964 at91_adc_writel(st, TRGR, status); 965 966 return 0; 967 } 968 969 static void at91_adc_reenable_trigger(struct iio_trigger *trig) 970 { 971 struct iio_dev *indio = iio_trigger_get_drvdata(trig); 972 struct at91_adc_state *st = iio_priv(indio); 973 974 /* if we are using DMA, we must not reenable irq after each trigger */ 975 if (st->dma_st.dma_chan) 976 return; 977 978 enable_irq(st->irq); 979 980 /* Needed to ACK the DRDY interruption */ 981 at91_adc_readl(st, LCDR); 982 } 983 984 static const struct iio_trigger_ops at91_adc_trigger_ops = { 985 .set_trigger_state = &at91_adc_configure_trigger, 986 .reenable = &at91_adc_reenable_trigger, 987 .validate_device = iio_trigger_validate_own_device, 988 }; 989 990 static int at91_adc_dma_size_done(struct at91_adc_state *st) 991 { 992 struct dma_tx_state state; 993 enum dma_status status; 994 int i, size; 995 996 status = dmaengine_tx_status(st->dma_st.dma_chan, 997 st->dma_st.dma_chan->cookie, 998 &state); 999 if (status != DMA_IN_PROGRESS) 1000 return 0; 1001 1002 /* Transferred length is size in bytes from end of buffer */ 1003 i = st->dma_st.rx_buf_sz - state.residue; 1004 1005 /* Return available bytes */ 1006 if (i >= st->dma_st.buf_idx) 1007 size = i - st->dma_st.buf_idx; 1008 else 1009 size = st->dma_st.rx_buf_sz + i - st->dma_st.buf_idx; 1010 return size; 1011 } 1012 1013 static void at91_dma_buffer_done(void *data) 1014 { 1015 struct iio_dev *indio_dev = data; 1016 1017 iio_trigger_poll_chained(indio_dev->trig); 1018 } 1019 1020 static int at91_adc_dma_start(struct iio_dev *indio_dev) 1021 { 1022 struct at91_adc_state *st = iio_priv(indio_dev); 1023 struct dma_async_tx_descriptor *desc; 1024 dma_cookie_t cookie; 1025 int ret; 1026 u8 bit; 1027 1028 if (!st->dma_st.dma_chan) 1029 return 0; 1030 1031 /* we start a new DMA, so set buffer index to start */ 1032 st->dma_st.buf_idx = 0; 1033 1034 /* 1035 * compute buffer size w.r.t. watermark and enabled channels. 1036 * scan_bytes is aligned so we need an exact size for DMA 1037 */ 1038 st->dma_st.rx_buf_sz = 0; 1039 1040 for_each_set_bit(bit, indio_dev->active_scan_mask, 1041 indio_dev->num_channels) { 1042 struct iio_chan_spec const *chan = 1043 at91_adc_chan_get(indio_dev, bit); 1044 1045 if (!chan) 1046 continue; 1047 1048 st->dma_st.rx_buf_sz += chan->scan_type.storagebits / 8; 1049 } 1050 st->dma_st.rx_buf_sz *= st->dma_st.watermark; 1051 1052 /* Prepare a DMA cyclic transaction */ 1053 desc = dmaengine_prep_dma_cyclic(st->dma_st.dma_chan, 1054 st->dma_st.rx_dma_buf, 1055 st->dma_st.rx_buf_sz, 1056 st->dma_st.rx_buf_sz / 2, 1057 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT); 1058 1059 if (!desc) { 1060 dev_err(&indio_dev->dev, "cannot prepare DMA cyclic\n"); 1061 return -EBUSY; 1062 } 1063 1064 desc->callback = at91_dma_buffer_done; 1065 desc->callback_param = indio_dev; 1066 1067 cookie = dmaengine_submit(desc); 1068 ret = dma_submit_error(cookie); 1069 if (ret) { 1070 dev_err(&indio_dev->dev, "cannot submit DMA cyclic\n"); 1071 dmaengine_terminate_async(st->dma_st.dma_chan); 1072 return ret; 1073 } 1074 1075 /* enable general overrun error signaling */ 1076 at91_adc_writel(st, IER, AT91_SAMA5D2_IER_GOVRE); 1077 /* Issue pending DMA requests */ 1078 dma_async_issue_pending(st->dma_st.dma_chan); 1079 1080 /* consider current time as DMA start time for timestamps */ 1081 st->dma_st.dma_ts = iio_get_time_ns(indio_dev); 1082 1083 dev_dbg(&indio_dev->dev, "DMA cyclic started\n"); 1084 1085 return 0; 1086 } 1087 1088 static bool at91_adc_buffer_check_use_irq(struct iio_dev *indio, 1089 struct at91_adc_state *st) 1090 { 1091 /* if using DMA, we do not use our own IRQ (we use DMA-controller) */ 1092 if (st->dma_st.dma_chan) 1093 return false; 1094 /* if the trigger is not ours, then it has its own IRQ */ 1095 if (iio_trigger_validate_own_device(indio->trig, indio)) 1096 return false; 1097 return true; 1098 } 1099 1100 static bool at91_adc_current_chan_is_touch(struct iio_dev *indio_dev) 1101 { 1102 struct at91_adc_state *st = iio_priv(indio_dev); 1103 1104 return !!bitmap_subset(indio_dev->active_scan_mask, 1105 &st->touch_st.channels_bitmask, 1106 st->soc_info.platform->max_index + 1); 1107 } 1108 1109 static int at91_adc_buffer_prepare(struct iio_dev *indio_dev) 1110 { 1111 int ret; 1112 u8 bit; 1113 struct at91_adc_state *st = iio_priv(indio_dev); 1114 1115 /* check if we are enabling triggered buffer or the touchscreen */ 1116 if (at91_adc_current_chan_is_touch(indio_dev)) 1117 return at91_adc_configure_touch(st, true); 1118 1119 /* if we are not in triggered mode, we cannot enable the buffer. */ 1120 if (!(indio_dev->currentmode & INDIO_ALL_TRIGGERED_MODES)) 1121 return -EINVAL; 1122 1123 /* we continue with the triggered buffer */ 1124 ret = at91_adc_dma_start(indio_dev); 1125 if (ret) { 1126 dev_err(&indio_dev->dev, "buffer prepare failed\n"); 1127 return ret; 1128 } 1129 1130 for_each_set_bit(bit, indio_dev->active_scan_mask, 1131 indio_dev->num_channels) { 1132 struct iio_chan_spec const *chan = 1133 at91_adc_chan_get(indio_dev, bit); 1134 if (!chan) 1135 continue; 1136 /* these channel types cannot be handled by this trigger */ 1137 if (chan->type == IIO_POSITIONRELATIVE || 1138 chan->type == IIO_PRESSURE) 1139 continue; 1140 1141 at91_adc_cor(st, chan); 1142 1143 at91_adc_writel(st, CHER, BIT(chan->channel)); 1144 } 1145 1146 if (at91_adc_buffer_check_use_irq(indio_dev, st)) 1147 at91_adc_writel(st, IER, AT91_SAMA5D2_IER_DRDY); 1148 1149 return 0; 1150 } 1151 1152 static int at91_adc_buffer_postdisable(struct iio_dev *indio_dev) 1153 { 1154 struct at91_adc_state *st = iio_priv(indio_dev); 1155 u8 bit; 1156 1157 /* check if we are disabling triggered buffer or the touchscreen */ 1158 if (at91_adc_current_chan_is_touch(indio_dev)) 1159 return at91_adc_configure_touch(st, false); 1160 1161 /* if we are not in triggered mode, nothing to do here */ 1162 if (!(indio_dev->currentmode & INDIO_ALL_TRIGGERED_MODES)) 1163 return -EINVAL; 1164 1165 /* 1166 * For each enable channel we must disable it in hardware. 1167 * In the case of DMA, we must read the last converted value 1168 * to clear EOC status and not get a possible interrupt later. 1169 * This value is being read by DMA from LCDR anyway, so it's not lost. 1170 */ 1171 for_each_set_bit(bit, indio_dev->active_scan_mask, 1172 indio_dev->num_channels) { 1173 struct iio_chan_spec const *chan = 1174 at91_adc_chan_get(indio_dev, bit); 1175 1176 if (!chan) 1177 continue; 1178 /* these channel types are virtual, no need to do anything */ 1179 if (chan->type == IIO_POSITIONRELATIVE || 1180 chan->type == IIO_PRESSURE) 1181 continue; 1182 1183 at91_adc_writel(st, CHDR, BIT(chan->channel)); 1184 1185 if (st->dma_st.dma_chan) 1186 at91_adc_read_chan(st, chan->address); 1187 } 1188 1189 if (at91_adc_buffer_check_use_irq(indio_dev, st)) 1190 at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_DRDY); 1191 1192 /* read overflow register to clear possible overflow status */ 1193 at91_adc_readl(st, OVER); 1194 1195 /* if we are using DMA we must clear registers and end DMA */ 1196 if (st->dma_st.dma_chan) 1197 dmaengine_terminate_sync(st->dma_st.dma_chan); 1198 1199 return 0; 1200 } 1201 1202 static const struct iio_buffer_setup_ops at91_buffer_setup_ops = { 1203 .postdisable = &at91_adc_buffer_postdisable, 1204 }; 1205 1206 static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *indio, 1207 char *trigger_name) 1208 { 1209 struct iio_trigger *trig; 1210 int ret; 1211 1212 trig = devm_iio_trigger_alloc(&indio->dev, "%s-dev%d-%s", indio->name, 1213 iio_device_id(indio), trigger_name); 1214 if (!trig) 1215 return NULL; 1216 1217 trig->dev.parent = indio->dev.parent; 1218 iio_trigger_set_drvdata(trig, indio); 1219 trig->ops = &at91_adc_trigger_ops; 1220 1221 ret = devm_iio_trigger_register(&indio->dev, trig); 1222 if (ret) 1223 return ERR_PTR(ret); 1224 1225 return trig; 1226 } 1227 static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev, 1228 struct iio_poll_func *pf) 1229 { 1230 struct at91_adc_state *st = iio_priv(indio_dev); 1231 int i = 0; 1232 int val; 1233 u8 bit; 1234 u32 mask = at91_adc_active_scan_mask_to_reg(indio_dev); 1235 unsigned int timeout = 50; 1236 u32 status, imr, eoc = 0, eoc_imr; 1237 1238 /* 1239 * Check if the conversion is ready. If not, wait a little bit, and 1240 * in case of timeout exit with an error. 1241 */ 1242 while (((eoc & mask) != mask) && timeout) { 1243 at91_adc_irq_status(st, &status, &eoc); 1244 at91_adc_irq_mask(st, &imr, &eoc_imr); 1245 usleep_range(50, 100); 1246 timeout--; 1247 } 1248 1249 /* Cannot read data, not ready. Continue without reporting data */ 1250 if (!timeout) 1251 return; 1252 1253 for_each_set_bit(bit, indio_dev->active_scan_mask, 1254 indio_dev->num_channels) { 1255 struct iio_chan_spec const *chan = 1256 at91_adc_chan_get(indio_dev, bit); 1257 1258 if (!chan) 1259 continue; 1260 /* 1261 * Our external trigger only supports the voltage channels. 1262 * In case someone requested a different type of channel 1263 * just put zeroes to buffer. 1264 * This should not happen because we check the scan mode 1265 * and scan mask when we enable the buffer, and we don't allow 1266 * the buffer to start with a mixed mask (voltage and something 1267 * else). 1268 * Thus, emit a warning. 1269 */ 1270 if (chan->type == IIO_VOLTAGE) { 1271 val = at91_adc_read_chan(st, chan->address); 1272 at91_adc_adjust_val_osr(st, &val); 1273 st->buffer[i] = val; 1274 } else { 1275 st->buffer[i] = 0; 1276 WARN(true, "This trigger cannot handle this type of channel"); 1277 } 1278 i++; 1279 } 1280 iio_push_to_buffers_with_timestamp(indio_dev, st->buffer, 1281 pf->timestamp); 1282 } 1283 1284 static void at91_adc_trigger_handler_dma(struct iio_dev *indio_dev) 1285 { 1286 struct at91_adc_state *st = iio_priv(indio_dev); 1287 int transferred_len = at91_adc_dma_size_done(st); 1288 s64 ns = iio_get_time_ns(indio_dev); 1289 s64 interval; 1290 int sample_index = 0, sample_count, sample_size; 1291 1292 u32 status = at91_adc_readl(st, ISR); 1293 /* if we reached this point, we cannot sample faster */ 1294 if (status & AT91_SAMA5D2_IER_GOVRE) 1295 pr_info_ratelimited("%s: conversion overrun detected\n", 1296 indio_dev->name); 1297 1298 sample_size = div_s64(st->dma_st.rx_buf_sz, st->dma_st.watermark); 1299 1300 sample_count = div_s64(transferred_len, sample_size); 1301 1302 /* 1303 * interval between samples is total time since last transfer handling 1304 * divided by the number of samples (total size divided by sample size) 1305 */ 1306 interval = div_s64((ns - st->dma_st.dma_ts), sample_count); 1307 1308 while (transferred_len >= sample_size) { 1309 /* 1310 * for all the values in the current sample, 1311 * adjust the values inside the buffer for oversampling 1312 */ 1313 at91_adc_adjust_val_osr_array(st, 1314 &st->dma_st.rx_buf[st->dma_st.buf_idx], 1315 sample_size); 1316 1317 iio_push_to_buffers_with_timestamp(indio_dev, 1318 (st->dma_st.rx_buf + st->dma_st.buf_idx), 1319 (st->dma_st.dma_ts + interval * sample_index)); 1320 /* adjust remaining length */ 1321 transferred_len -= sample_size; 1322 /* adjust buffer index */ 1323 st->dma_st.buf_idx += sample_size; 1324 /* in case of reaching end of buffer, reset index */ 1325 if (st->dma_st.buf_idx >= st->dma_st.rx_buf_sz) 1326 st->dma_st.buf_idx = 0; 1327 sample_index++; 1328 } 1329 /* adjust saved time for next transfer handling */ 1330 st->dma_st.dma_ts = iio_get_time_ns(indio_dev); 1331 } 1332 1333 static irqreturn_t at91_adc_trigger_handler(int irq, void *p) 1334 { 1335 struct iio_poll_func *pf = p; 1336 struct iio_dev *indio_dev = pf->indio_dev; 1337 struct at91_adc_state *st = iio_priv(indio_dev); 1338 1339 /* 1340 * If it's not our trigger, start a conversion now, as we are 1341 * actually polling the trigger now. 1342 */ 1343 if (iio_trigger_validate_own_device(indio_dev->trig, indio_dev)) 1344 at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START); 1345 1346 if (st->dma_st.dma_chan) 1347 at91_adc_trigger_handler_dma(indio_dev); 1348 else 1349 at91_adc_trigger_handler_nodma(indio_dev, pf); 1350 1351 iio_trigger_notify_done(indio_dev->trig); 1352 1353 return IRQ_HANDLED; 1354 } 1355 1356 static unsigned at91_adc_startup_time(unsigned startup_time_min, 1357 unsigned adc_clk_khz) 1358 { 1359 static const unsigned int startup_lookup[] = { 1360 0, 8, 16, 24, 1361 64, 80, 96, 112, 1362 512, 576, 640, 704, 1363 768, 832, 896, 960 1364 }; 1365 unsigned ticks_min, i; 1366 1367 /* 1368 * Since the adc frequency is checked before, there is no reason 1369 * to not meet the startup time constraint. 1370 */ 1371 1372 ticks_min = startup_time_min * adc_clk_khz / 1000; 1373 for (i = 0; i < ARRAY_SIZE(startup_lookup); i++) 1374 if (startup_lookup[i] > ticks_min) 1375 break; 1376 1377 return i; 1378 } 1379 1380 static void at91_adc_setup_samp_freq(struct iio_dev *indio_dev, unsigned freq) 1381 { 1382 struct at91_adc_state *st = iio_priv(indio_dev); 1383 unsigned f_per, prescal, startup, mr; 1384 1385 f_per = clk_get_rate(st->per_clk); 1386 prescal = (f_per / (2 * freq)) - 1; 1387 1388 startup = at91_adc_startup_time(st->soc_info.startup_time, 1389 freq / 1000); 1390 1391 mr = at91_adc_readl(st, MR); 1392 mr &= ~(AT91_SAMA5D2_MR_STARTUP_MASK | AT91_SAMA5D2_MR_PRESCAL_MASK); 1393 mr |= AT91_SAMA5D2_MR_STARTUP(startup); 1394 mr |= AT91_SAMA5D2_MR_PRESCAL(prescal); 1395 at91_adc_writel(st, MR, mr); 1396 1397 dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u\n", 1398 freq, startup, prescal); 1399 st->current_sample_rate = freq; 1400 } 1401 1402 static inline unsigned at91_adc_get_sample_freq(struct at91_adc_state *st) 1403 { 1404 return st->current_sample_rate; 1405 } 1406 1407 static void at91_adc_touch_data_handler(struct iio_dev *indio_dev) 1408 { 1409 struct at91_adc_state *st = iio_priv(indio_dev); 1410 u8 bit; 1411 u16 val; 1412 int i = 0; 1413 1414 for_each_set_bit(bit, indio_dev->active_scan_mask, 1415 st->soc_info.platform->max_index + 1) { 1416 struct iio_chan_spec const *chan = 1417 at91_adc_chan_get(indio_dev, bit); 1418 1419 if (chan->type == IIO_POSITIONRELATIVE) 1420 at91_adc_read_position(st, chan->channel, &val); 1421 else if (chan->type == IIO_PRESSURE) 1422 at91_adc_read_pressure(st, chan->channel, &val); 1423 else 1424 continue; 1425 st->buffer[i] = val; 1426 i++; 1427 } 1428 /* 1429 * Schedule work to push to buffers. 1430 * This is intended to push to the callback buffer that another driver 1431 * registered. We are still in a handler from our IRQ. If we push 1432 * directly, it means the other driver has it's callback called 1433 * from our IRQ context. Which is something we better avoid. 1434 * Let's schedule it after our IRQ is completed. 1435 */ 1436 schedule_work(&st->touch_st.workq); 1437 } 1438 1439 static void at91_adc_pen_detect_interrupt(struct at91_adc_state *st) 1440 { 1441 at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_PEN); 1442 at91_adc_writel(st, IER, AT91_SAMA5D2_IER_NOPEN | 1443 AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY | 1444 AT91_SAMA5D2_IER_PRDY); 1445 at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC | 1446 AT91_SAMA5D2_TRGR_TRGPER(st->touch_st.sample_period_val)); 1447 st->touch_st.touching = true; 1448 } 1449 1450 static void at91_adc_no_pen_detect_interrupt(struct iio_dev *indio_dev) 1451 { 1452 struct at91_adc_state *st = iio_priv(indio_dev); 1453 1454 at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER); 1455 at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_NOPEN | 1456 AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY | 1457 AT91_SAMA5D2_IER_PRDY); 1458 st->touch_st.touching = false; 1459 1460 at91_adc_touch_data_handler(indio_dev); 1461 1462 at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN); 1463 } 1464 1465 static void at91_adc_workq_handler(struct work_struct *workq) 1466 { 1467 struct at91_adc_touch *touch_st = container_of(workq, 1468 struct at91_adc_touch, workq); 1469 struct at91_adc_state *st = container_of(touch_st, 1470 struct at91_adc_state, touch_st); 1471 struct iio_dev *indio_dev = st->indio_dev; 1472 1473 iio_push_to_buffers(indio_dev, st->buffer); 1474 } 1475 1476 static irqreturn_t at91_adc_interrupt(int irq, void *private) 1477 { 1478 struct iio_dev *indio = private; 1479 struct at91_adc_state *st = iio_priv(indio); 1480 u32 status, eoc, imr, eoc_imr; 1481 u32 rdy_mask = AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY | 1482 AT91_SAMA5D2_IER_PRDY; 1483 1484 at91_adc_irq_status(st, &status, &eoc); 1485 at91_adc_irq_mask(st, &imr, &eoc_imr); 1486 1487 if (!(status & imr) && !(eoc & eoc_imr)) 1488 return IRQ_NONE; 1489 if (status & AT91_SAMA5D2_IER_PEN) { 1490 /* pen detected IRQ */ 1491 at91_adc_pen_detect_interrupt(st); 1492 } else if ((status & AT91_SAMA5D2_IER_NOPEN)) { 1493 /* nopen detected IRQ */ 1494 at91_adc_no_pen_detect_interrupt(indio); 1495 } else if ((status & AT91_SAMA5D2_ISR_PENS) && 1496 ((status & rdy_mask) == rdy_mask)) { 1497 /* periodic trigger IRQ - during pen sense */ 1498 at91_adc_touch_data_handler(indio); 1499 } else if (status & AT91_SAMA5D2_ISR_PENS) { 1500 /* 1501 * touching, but the measurements are not ready yet. 1502 * read and ignore. 1503 */ 1504 status = at91_adc_readl(st, XPOSR); 1505 status = at91_adc_readl(st, YPOSR); 1506 status = at91_adc_readl(st, PRESSR); 1507 } else if (iio_buffer_enabled(indio) && 1508 (status & AT91_SAMA5D2_IER_DRDY)) { 1509 /* triggered buffer without DMA */ 1510 disable_irq_nosync(irq); 1511 iio_trigger_poll(indio->trig); 1512 } else if (iio_buffer_enabled(indio) && st->dma_st.dma_chan) { 1513 /* triggered buffer with DMA - should not happen */ 1514 disable_irq_nosync(irq); 1515 WARN(true, "Unexpected irq occurred\n"); 1516 } else if (!iio_buffer_enabled(indio)) { 1517 /* software requested conversion */ 1518 st->conversion_value = at91_adc_read_chan(st, st->chan->address); 1519 st->conversion_done = true; 1520 wake_up_interruptible(&st->wq_data_available); 1521 } 1522 return IRQ_HANDLED; 1523 } 1524 1525 static int at91_adc_read_info_raw(struct iio_dev *indio_dev, 1526 struct iio_chan_spec const *chan, int *val) 1527 { 1528 struct at91_adc_state *st = iio_priv(indio_dev); 1529 u16 tmp_val; 1530 int ret; 1531 1532 /* 1533 * Keep in mind that we cannot use software trigger or touchscreen 1534 * if external trigger is enabled 1535 */ 1536 if (chan->type == IIO_POSITIONRELATIVE) { 1537 ret = iio_device_claim_direct_mode(indio_dev); 1538 if (ret) 1539 return ret; 1540 mutex_lock(&st->lock); 1541 1542 ret = at91_adc_read_position(st, chan->channel, 1543 &tmp_val); 1544 *val = tmp_val; 1545 mutex_unlock(&st->lock); 1546 iio_device_release_direct_mode(indio_dev); 1547 1548 return at91_adc_adjust_val_osr(st, val); 1549 } 1550 if (chan->type == IIO_PRESSURE) { 1551 ret = iio_device_claim_direct_mode(indio_dev); 1552 if (ret) 1553 return ret; 1554 mutex_lock(&st->lock); 1555 1556 ret = at91_adc_read_pressure(st, chan->channel, 1557 &tmp_val); 1558 *val = tmp_val; 1559 mutex_unlock(&st->lock); 1560 iio_device_release_direct_mode(indio_dev); 1561 1562 return at91_adc_adjust_val_osr(st, val); 1563 } 1564 1565 /* in this case we have a voltage channel */ 1566 1567 ret = iio_device_claim_direct_mode(indio_dev); 1568 if (ret) 1569 return ret; 1570 mutex_lock(&st->lock); 1571 1572 st->chan = chan; 1573 1574 at91_adc_cor(st, chan); 1575 at91_adc_writel(st, CHER, BIT(chan->channel)); 1576 at91_adc_eoc_ena(st, chan->channel); 1577 at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START); 1578 1579 ret = wait_event_interruptible_timeout(st->wq_data_available, 1580 st->conversion_done, 1581 msecs_to_jiffies(1000)); 1582 if (ret == 0) 1583 ret = -ETIMEDOUT; 1584 1585 if (ret > 0) { 1586 *val = st->conversion_value; 1587 ret = at91_adc_adjust_val_osr(st, val); 1588 if (chan->scan_type.sign == 's') 1589 *val = sign_extend32(*val, 1590 chan->scan_type.realbits - 1); 1591 st->conversion_done = false; 1592 } 1593 1594 at91_adc_eoc_dis(st, st->chan->channel); 1595 at91_adc_writel(st, CHDR, BIT(chan->channel)); 1596 1597 /* Needed to ACK the DRDY interruption */ 1598 at91_adc_readl(st, LCDR); 1599 1600 mutex_unlock(&st->lock); 1601 1602 iio_device_release_direct_mode(indio_dev); 1603 return ret; 1604 } 1605 1606 static int at91_adc_read_raw(struct iio_dev *indio_dev, 1607 struct iio_chan_spec const *chan, 1608 int *val, int *val2, long mask) 1609 { 1610 struct at91_adc_state *st = iio_priv(indio_dev); 1611 1612 switch (mask) { 1613 case IIO_CHAN_INFO_RAW: 1614 return at91_adc_read_info_raw(indio_dev, chan, val); 1615 case IIO_CHAN_INFO_SCALE: 1616 *val = st->vref_uv / 1000; 1617 if (chan->differential) 1618 *val *= 2; 1619 *val2 = chan->scan_type.realbits; 1620 return IIO_VAL_FRACTIONAL_LOG2; 1621 1622 case IIO_CHAN_INFO_SAMP_FREQ: 1623 *val = at91_adc_get_sample_freq(st); 1624 return IIO_VAL_INT; 1625 1626 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 1627 *val = st->oversampling_ratio; 1628 return IIO_VAL_INT; 1629 1630 default: 1631 return -EINVAL; 1632 } 1633 } 1634 1635 static int at91_adc_write_raw(struct iio_dev *indio_dev, 1636 struct iio_chan_spec const *chan, 1637 int val, int val2, long mask) 1638 { 1639 struct at91_adc_state *st = iio_priv(indio_dev); 1640 1641 switch (mask) { 1642 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 1643 if ((val != AT91_OSR_1SAMPLES) && (val != AT91_OSR_4SAMPLES) && 1644 (val != AT91_OSR_16SAMPLES)) 1645 return -EINVAL; 1646 /* if no change, optimize out */ 1647 if (val == st->oversampling_ratio) 1648 return 0; 1649 st->oversampling_ratio = val; 1650 /* update ratio */ 1651 at91_adc_config_emr(st); 1652 return 0; 1653 case IIO_CHAN_INFO_SAMP_FREQ: 1654 if (val < st->soc_info.min_sample_rate || 1655 val > st->soc_info.max_sample_rate) 1656 return -EINVAL; 1657 1658 at91_adc_setup_samp_freq(indio_dev, val); 1659 return 0; 1660 default: 1661 return -EINVAL; 1662 } 1663 } 1664 1665 static void at91_adc_dma_init(struct at91_adc_state *st) 1666 { 1667 struct device *dev = &st->indio_dev->dev; 1668 struct dma_slave_config config = {0}; 1669 /* we have 2 bytes for each channel */ 1670 unsigned int sample_size = st->soc_info.platform->nr_channels * 2; 1671 /* 1672 * We make the buffer double the size of the fifo, 1673 * such that DMA uses one half of the buffer (full fifo size) 1674 * and the software uses the other half to read/write. 1675 */ 1676 unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE * 1677 sample_size * 2, PAGE_SIZE); 1678 1679 if (st->dma_st.dma_chan) 1680 return; 1681 1682 st->dma_st.dma_chan = dma_request_chan(dev, "rx"); 1683 if (IS_ERR(st->dma_st.dma_chan)) { 1684 dev_info(dev, "can't get DMA channel\n"); 1685 st->dma_st.dma_chan = NULL; 1686 goto dma_exit; 1687 } 1688 1689 st->dma_st.rx_buf = dma_alloc_coherent(st->dma_st.dma_chan->device->dev, 1690 pages * PAGE_SIZE, 1691 &st->dma_st.rx_dma_buf, 1692 GFP_KERNEL); 1693 if (!st->dma_st.rx_buf) { 1694 dev_info(dev, "can't allocate coherent DMA area\n"); 1695 goto dma_chan_disable; 1696 } 1697 1698 /* Configure DMA channel to read data register */ 1699 config.direction = DMA_DEV_TO_MEM; 1700 config.src_addr = (phys_addr_t)(st->dma_st.phys_addr 1701 + st->soc_info.platform->layout->LCDR); 1702 config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; 1703 config.src_maxburst = 1; 1704 config.dst_maxburst = 1; 1705 1706 if (dmaengine_slave_config(st->dma_st.dma_chan, &config)) { 1707 dev_info(dev, "can't configure DMA slave\n"); 1708 goto dma_free_area; 1709 } 1710 1711 dev_info(dev, "using %s for rx DMA transfers\n", 1712 dma_chan_name(st->dma_st.dma_chan)); 1713 1714 return; 1715 1716 dma_free_area: 1717 dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE, 1718 st->dma_st.rx_buf, st->dma_st.rx_dma_buf); 1719 dma_chan_disable: 1720 dma_release_channel(st->dma_st.dma_chan); 1721 st->dma_st.dma_chan = NULL; 1722 dma_exit: 1723 dev_info(dev, "continuing without DMA support\n"); 1724 } 1725 1726 static void at91_adc_dma_disable(struct at91_adc_state *st) 1727 { 1728 struct device *dev = &st->indio_dev->dev; 1729 /* we have 2 bytes for each channel */ 1730 unsigned int sample_size = st->soc_info.platform->nr_channels * 2; 1731 unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE * 1732 sample_size * 2, PAGE_SIZE); 1733 1734 /* if we are not using DMA, just return */ 1735 if (!st->dma_st.dma_chan) 1736 return; 1737 1738 /* wait for all transactions to be terminated first*/ 1739 dmaengine_terminate_sync(st->dma_st.dma_chan); 1740 1741 dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE, 1742 st->dma_st.rx_buf, st->dma_st.rx_dma_buf); 1743 dma_release_channel(st->dma_st.dma_chan); 1744 st->dma_st.dma_chan = NULL; 1745 1746 dev_info(dev, "continuing without DMA support\n"); 1747 } 1748 1749 static int at91_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val) 1750 { 1751 struct at91_adc_state *st = iio_priv(indio_dev); 1752 int ret; 1753 1754 if (val > AT91_HWFIFO_MAX_SIZE) 1755 return -EINVAL; 1756 1757 if (!st->selected_trig->hw_trig) { 1758 dev_dbg(&indio_dev->dev, "we need hw trigger for DMA\n"); 1759 return 0; 1760 } 1761 1762 dev_dbg(&indio_dev->dev, "new watermark is %u\n", val); 1763 st->dma_st.watermark = val; 1764 1765 /* 1766 * The logic here is: if we have watermark 1, it means we do 1767 * each conversion with it's own IRQ, thus we don't need DMA. 1768 * If the watermark is higher, we do DMA to do all the transfers in bulk 1769 */ 1770 1771 if (val == 1) 1772 at91_adc_dma_disable(st); 1773 else if (val > 1) 1774 at91_adc_dma_init(st); 1775 1776 /* 1777 * We can start the DMA only after setting the watermark and 1778 * having the DMA initialization completed 1779 */ 1780 ret = at91_adc_buffer_prepare(indio_dev); 1781 if (ret) 1782 at91_adc_dma_disable(st); 1783 1784 return ret; 1785 } 1786 1787 static int at91_adc_update_scan_mode(struct iio_dev *indio_dev, 1788 const unsigned long *scan_mask) 1789 { 1790 struct at91_adc_state *st = iio_priv(indio_dev); 1791 1792 if (bitmap_subset(scan_mask, &st->touch_st.channels_bitmask, 1793 st->soc_info.platform->max_index + 1)) 1794 return 0; 1795 /* 1796 * if the new bitmap is a combination of touchscreen and regular 1797 * channels, then we are not fine 1798 */ 1799 if (bitmap_intersects(&st->touch_st.channels_bitmask, scan_mask, 1800 st->soc_info.platform->max_index + 1)) 1801 return -EINVAL; 1802 return 0; 1803 } 1804 1805 static void at91_adc_hw_init(struct iio_dev *indio_dev) 1806 { 1807 struct at91_adc_state *st = iio_priv(indio_dev); 1808 1809 at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST); 1810 if (st->soc_info.platform->layout->EOC_IDR) 1811 at91_adc_writel(st, EOC_IDR, 0xffffffff); 1812 at91_adc_writel(st, IDR, 0xffffffff); 1813 /* 1814 * Transfer field must be set to 2 according to the datasheet and 1815 * allows different analog settings for each channel. 1816 */ 1817 at91_adc_writel(st, MR, 1818 AT91_SAMA5D2_MR_TRANSFER(2) | AT91_SAMA5D2_MR_ANACH); 1819 1820 at91_adc_setup_samp_freq(indio_dev, st->soc_info.min_sample_rate); 1821 1822 /* configure extended mode register */ 1823 at91_adc_config_emr(st); 1824 } 1825 1826 static ssize_t at91_adc_get_fifo_state(struct device *dev, 1827 struct device_attribute *attr, char *buf) 1828 { 1829 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 1830 struct at91_adc_state *st = iio_priv(indio_dev); 1831 1832 return scnprintf(buf, PAGE_SIZE, "%d\n", !!st->dma_st.dma_chan); 1833 } 1834 1835 static ssize_t at91_adc_get_watermark(struct device *dev, 1836 struct device_attribute *attr, char *buf) 1837 { 1838 struct iio_dev *indio_dev = dev_to_iio_dev(dev); 1839 struct at91_adc_state *st = iio_priv(indio_dev); 1840 1841 return scnprintf(buf, PAGE_SIZE, "%d\n", st->dma_st.watermark); 1842 } 1843 1844 static IIO_DEVICE_ATTR(hwfifo_enabled, 0444, 1845 at91_adc_get_fifo_state, NULL, 0); 1846 static IIO_DEVICE_ATTR(hwfifo_watermark, 0444, 1847 at91_adc_get_watermark, NULL, 0); 1848 1849 static IIO_CONST_ATTR(hwfifo_watermark_min, "2"); 1850 static IIO_CONST_ATTR(hwfifo_watermark_max, AT91_HWFIFO_MAX_SIZE_STR); 1851 1852 static IIO_CONST_ATTR(oversampling_ratio_available, 1853 __stringify(AT91_OSR_1SAMPLES) " " 1854 __stringify(AT91_OSR_4SAMPLES) " " 1855 __stringify(AT91_OSR_16SAMPLES)); 1856 1857 static struct attribute *at91_adc_attributes[] = { 1858 &iio_const_attr_oversampling_ratio_available.dev_attr.attr, 1859 NULL, 1860 }; 1861 1862 static const struct attribute_group at91_adc_attribute_group = { 1863 .attrs = at91_adc_attributes, 1864 }; 1865 1866 static const struct attribute *at91_adc_fifo_attributes[] = { 1867 &iio_const_attr_hwfifo_watermark_min.dev_attr.attr, 1868 &iio_const_attr_hwfifo_watermark_max.dev_attr.attr, 1869 &iio_dev_attr_hwfifo_watermark.dev_attr.attr, 1870 &iio_dev_attr_hwfifo_enabled.dev_attr.attr, 1871 NULL, 1872 }; 1873 1874 static const struct iio_info at91_adc_info = { 1875 .attrs = &at91_adc_attribute_group, 1876 .read_raw = &at91_adc_read_raw, 1877 .write_raw = &at91_adc_write_raw, 1878 .update_scan_mode = &at91_adc_update_scan_mode, 1879 .of_xlate = &at91_adc_of_xlate, 1880 .hwfifo_set_watermark = &at91_adc_set_watermark, 1881 }; 1882 1883 static int at91_adc_buffer_and_trigger_init(struct device *dev, 1884 struct iio_dev *indio) 1885 { 1886 struct at91_adc_state *st = iio_priv(indio); 1887 const struct attribute **fifo_attrs; 1888 int ret; 1889 1890 if (st->selected_trig->hw_trig) 1891 fifo_attrs = at91_adc_fifo_attributes; 1892 else 1893 fifo_attrs = NULL; 1894 1895 ret = devm_iio_triggered_buffer_setup_ext(&indio->dev, indio, 1896 &iio_pollfunc_store_time, &at91_adc_trigger_handler, 1897 IIO_BUFFER_DIRECTION_IN, &at91_buffer_setup_ops, fifo_attrs); 1898 if (ret < 0) { 1899 dev_err(dev, "couldn't initialize the buffer.\n"); 1900 return ret; 1901 } 1902 1903 if (!st->selected_trig->hw_trig) 1904 return 0; 1905 1906 st->trig = at91_adc_allocate_trigger(indio, st->selected_trig->name); 1907 if (IS_ERR(st->trig)) { 1908 dev_err(dev, "could not allocate trigger\n"); 1909 return PTR_ERR(st->trig); 1910 } 1911 1912 /* 1913 * Initially the iio buffer has a length of 2 and 1914 * a watermark of 1 1915 */ 1916 st->dma_st.watermark = 1; 1917 1918 return 0; 1919 } 1920 1921 static int at91_adc_probe(struct platform_device *pdev) 1922 { 1923 struct iio_dev *indio_dev; 1924 struct at91_adc_state *st; 1925 struct resource *res; 1926 int ret, i; 1927 u32 edge_type = IRQ_TYPE_NONE; 1928 1929 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st)); 1930 if (!indio_dev) 1931 return -ENOMEM; 1932 1933 st = iio_priv(indio_dev); 1934 st->indio_dev = indio_dev; 1935 1936 st->soc_info.platform = of_device_get_match_data(&pdev->dev); 1937 1938 indio_dev->name = dev_name(&pdev->dev); 1939 indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE; 1940 indio_dev->info = &at91_adc_info; 1941 indio_dev->channels = *st->soc_info.platform->adc_channels; 1942 indio_dev->num_channels = st->soc_info.platform->max_channels; 1943 1944 bitmap_set(&st->touch_st.channels_bitmask, 1945 st->soc_info.platform->touch_chan_x, 1); 1946 bitmap_set(&st->touch_st.channels_bitmask, 1947 st->soc_info.platform->touch_chan_y, 1); 1948 bitmap_set(&st->touch_st.channels_bitmask, 1949 st->soc_info.platform->touch_chan_p, 1); 1950 1951 st->oversampling_ratio = AT91_OSR_1SAMPLES; 1952 1953 ret = of_property_read_u32(pdev->dev.of_node, 1954 "atmel,min-sample-rate-hz", 1955 &st->soc_info.min_sample_rate); 1956 if (ret) { 1957 dev_err(&pdev->dev, 1958 "invalid or missing value for atmel,min-sample-rate-hz\n"); 1959 return ret; 1960 } 1961 1962 ret = of_property_read_u32(pdev->dev.of_node, 1963 "atmel,max-sample-rate-hz", 1964 &st->soc_info.max_sample_rate); 1965 if (ret) { 1966 dev_err(&pdev->dev, 1967 "invalid or missing value for atmel,max-sample-rate-hz\n"); 1968 return ret; 1969 } 1970 1971 ret = of_property_read_u32(pdev->dev.of_node, "atmel,startup-time-ms", 1972 &st->soc_info.startup_time); 1973 if (ret) { 1974 dev_err(&pdev->dev, 1975 "invalid or missing value for atmel,startup-time-ms\n"); 1976 return ret; 1977 } 1978 1979 ret = of_property_read_u32(pdev->dev.of_node, 1980 "atmel,trigger-edge-type", &edge_type); 1981 if (ret) { 1982 dev_dbg(&pdev->dev, 1983 "atmel,trigger-edge-type not specified, only software trigger available\n"); 1984 } 1985 1986 st->selected_trig = NULL; 1987 1988 /* find the right trigger, or no trigger at all */ 1989 for (i = 0; i < st->soc_info.platform->hw_trig_cnt + 1; i++) 1990 if (at91_adc_trigger_list[i].edge_type == edge_type) { 1991 st->selected_trig = &at91_adc_trigger_list[i]; 1992 break; 1993 } 1994 1995 if (!st->selected_trig) { 1996 dev_err(&pdev->dev, "invalid external trigger edge value\n"); 1997 return -EINVAL; 1998 } 1999 2000 init_waitqueue_head(&st->wq_data_available); 2001 mutex_init(&st->lock); 2002 INIT_WORK(&st->touch_st.workq, at91_adc_workq_handler); 2003 2004 st->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res); 2005 if (IS_ERR(st->base)) 2006 return PTR_ERR(st->base); 2007 2008 /* if we plan to use DMA, we need the physical address of the regs */ 2009 st->dma_st.phys_addr = res->start; 2010 2011 st->irq = platform_get_irq(pdev, 0); 2012 if (st->irq <= 0) { 2013 if (!st->irq) 2014 st->irq = -ENXIO; 2015 2016 return st->irq; 2017 } 2018 2019 st->per_clk = devm_clk_get(&pdev->dev, "adc_clk"); 2020 if (IS_ERR(st->per_clk)) 2021 return PTR_ERR(st->per_clk); 2022 2023 st->reg = devm_regulator_get(&pdev->dev, "vddana"); 2024 if (IS_ERR(st->reg)) 2025 return PTR_ERR(st->reg); 2026 2027 st->vref = devm_regulator_get(&pdev->dev, "vref"); 2028 if (IS_ERR(st->vref)) 2029 return PTR_ERR(st->vref); 2030 2031 ret = devm_request_irq(&pdev->dev, st->irq, at91_adc_interrupt, 0, 2032 pdev->dev.driver->name, indio_dev); 2033 if (ret) 2034 return ret; 2035 2036 ret = regulator_enable(st->reg); 2037 if (ret) 2038 return ret; 2039 2040 ret = regulator_enable(st->vref); 2041 if (ret) 2042 goto reg_disable; 2043 2044 st->vref_uv = regulator_get_voltage(st->vref); 2045 if (st->vref_uv <= 0) { 2046 ret = -EINVAL; 2047 goto vref_disable; 2048 } 2049 2050 ret = clk_prepare_enable(st->per_clk); 2051 if (ret) 2052 goto vref_disable; 2053 2054 at91_adc_hw_init(indio_dev); 2055 2056 platform_set_drvdata(pdev, indio_dev); 2057 2058 ret = at91_adc_buffer_and_trigger_init(&pdev->dev, indio_dev); 2059 if (ret < 0) 2060 goto per_clk_disable_unprepare; 2061 2062 if (dma_coerce_mask_and_coherent(&indio_dev->dev, DMA_BIT_MASK(32))) 2063 dev_info(&pdev->dev, "cannot set DMA mask to 32-bit\n"); 2064 2065 ret = iio_device_register(indio_dev); 2066 if (ret < 0) 2067 goto dma_disable; 2068 2069 if (st->selected_trig->hw_trig) 2070 dev_info(&pdev->dev, "setting up trigger as %s\n", 2071 st->selected_trig->name); 2072 2073 dev_info(&pdev->dev, "version: %x\n", 2074 readl_relaxed(st->base + st->soc_info.platform->layout->VERSION)); 2075 2076 return 0; 2077 2078 dma_disable: 2079 at91_adc_dma_disable(st); 2080 per_clk_disable_unprepare: 2081 clk_disable_unprepare(st->per_clk); 2082 vref_disable: 2083 regulator_disable(st->vref); 2084 reg_disable: 2085 regulator_disable(st->reg); 2086 return ret; 2087 } 2088 2089 static int at91_adc_remove(struct platform_device *pdev) 2090 { 2091 struct iio_dev *indio_dev = platform_get_drvdata(pdev); 2092 struct at91_adc_state *st = iio_priv(indio_dev); 2093 2094 iio_device_unregister(indio_dev); 2095 2096 at91_adc_dma_disable(st); 2097 2098 clk_disable_unprepare(st->per_clk); 2099 2100 regulator_disable(st->vref); 2101 regulator_disable(st->reg); 2102 2103 return 0; 2104 } 2105 2106 static __maybe_unused int at91_adc_suspend(struct device *dev) 2107 { 2108 struct iio_dev *indio_dev = dev_get_drvdata(dev); 2109 struct at91_adc_state *st = iio_priv(indio_dev); 2110 2111 /* 2112 * Do a sofware reset of the ADC before we go to suspend. 2113 * this will ensure that all pins are free from being muxed by the ADC 2114 * and can be used by for other devices. 2115 * Otherwise, ADC will hog them and we can't go to suspend mode. 2116 */ 2117 at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST); 2118 2119 clk_disable_unprepare(st->per_clk); 2120 regulator_disable(st->vref); 2121 regulator_disable(st->reg); 2122 2123 return pinctrl_pm_select_sleep_state(dev); 2124 } 2125 2126 static __maybe_unused int at91_adc_resume(struct device *dev) 2127 { 2128 struct iio_dev *indio_dev = dev_get_drvdata(dev); 2129 struct at91_adc_state *st = iio_priv(indio_dev); 2130 int ret; 2131 2132 ret = pinctrl_pm_select_default_state(dev); 2133 if (ret) 2134 goto resume_failed; 2135 2136 ret = regulator_enable(st->reg); 2137 if (ret) 2138 goto resume_failed; 2139 2140 ret = regulator_enable(st->vref); 2141 if (ret) 2142 goto reg_disable_resume; 2143 2144 ret = clk_prepare_enable(st->per_clk); 2145 if (ret) 2146 goto vref_disable_resume; 2147 2148 at91_adc_hw_init(indio_dev); 2149 2150 /* reconfiguring trigger hardware state */ 2151 if (!iio_buffer_enabled(indio_dev)) 2152 return 0; 2153 2154 /* check if we are enabling triggered buffer or the touchscreen */ 2155 if (at91_adc_current_chan_is_touch(indio_dev)) 2156 return at91_adc_configure_touch(st, true); 2157 else 2158 return at91_adc_configure_trigger(st->trig, true); 2159 2160 /* not needed but more explicit */ 2161 return 0; 2162 2163 vref_disable_resume: 2164 regulator_disable(st->vref); 2165 reg_disable_resume: 2166 regulator_disable(st->reg); 2167 resume_failed: 2168 dev_err(&indio_dev->dev, "failed to resume\n"); 2169 return ret; 2170 } 2171 2172 static SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend, at91_adc_resume); 2173 2174 static const struct of_device_id at91_adc_dt_match[] = { 2175 { 2176 .compatible = "atmel,sama5d2-adc", 2177 .data = (const void *)&sama5d2_platform, 2178 }, { 2179 .compatible = "microchip,sama7g5-adc", 2180 .data = (const void *)&sama7g5_platform, 2181 }, { 2182 /* sentinel */ 2183 } 2184 }; 2185 MODULE_DEVICE_TABLE(of, at91_adc_dt_match); 2186 2187 static struct platform_driver at91_adc_driver = { 2188 .probe = at91_adc_probe, 2189 .remove = at91_adc_remove, 2190 .driver = { 2191 .name = "at91-sama5d2_adc", 2192 .of_match_table = at91_adc_dt_match, 2193 .pm = &at91_adc_pm_ops, 2194 }, 2195 }; 2196 module_platform_driver(at91_adc_driver) 2197 2198 MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@microchip.com>"); 2199 MODULE_AUTHOR("Eugen Hristev <eugen.hristev@microchip.com"); 2200 MODULE_DESCRIPTION("Atmel AT91 SAMA5D2 ADC"); 2201 MODULE_LICENSE("GPL v2"); 2202