1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * This file is part of STM32 ADC driver 4 * 5 * Copyright (C) 2016, STMicroelectronics - All Rights Reserved 6 * Author: Fabrice Gasnier <fabrice.gasnier@st.com>. 7 */ 8 9 #include <linux/clk.h> 10 #include <linux/delay.h> 11 #include <linux/dma-mapping.h> 12 #include <linux/dmaengine.h> 13 #include <linux/iio/iio.h> 14 #include <linux/iio/buffer.h> 15 #include <linux/iio/timer/stm32-lptim-trigger.h> 16 #include <linux/iio/timer/stm32-timer-trigger.h> 17 #include <linux/iio/trigger.h> 18 #include <linux/iio/trigger_consumer.h> 19 #include <linux/iio/triggered_buffer.h> 20 #include <linux/interrupt.h> 21 #include <linux/io.h> 22 #include <linux/iopoll.h> 23 #include <linux/module.h> 24 #include <linux/platform_device.h> 25 #include <linux/pm_runtime.h> 26 #include <linux/of.h> 27 #include <linux/of_device.h> 28 29 #include "stm32-adc-core.h" 30 31 /* Number of linear calibration shadow registers / LINCALRDYW control bits */ 32 #define STM32H7_LINCALFACT_NUM 6 33 34 /* BOOST bit must be set on STM32H7 when ADC clock is above 20MHz */ 35 #define STM32H7_BOOST_CLKRATE 20000000UL 36 37 #define STM32_ADC_CH_MAX 20 /* max number of channels */ 38 #define STM32_ADC_CH_SZ 10 /* max channel name size */ 39 #define STM32_ADC_MAX_SQ 16 /* SQ1..SQ16 */ 40 #define STM32_ADC_MAX_SMP 7 /* SMPx range is [0..7] */ 41 #define STM32_ADC_TIMEOUT_US 100000 42 #define STM32_ADC_TIMEOUT (msecs_to_jiffies(STM32_ADC_TIMEOUT_US / 1000)) 43 #define STM32_ADC_HW_STOP_DELAY_MS 100 44 45 #define STM32_DMA_BUFFER_SIZE PAGE_SIZE 46 47 /* External trigger enable */ 48 enum stm32_adc_exten { 49 STM32_EXTEN_SWTRIG, 50 STM32_EXTEN_HWTRIG_RISING_EDGE, 51 STM32_EXTEN_HWTRIG_FALLING_EDGE, 52 STM32_EXTEN_HWTRIG_BOTH_EDGES, 53 }; 54 55 /* extsel - trigger mux selection value */ 56 enum stm32_adc_extsel { 57 STM32_EXT0, 58 STM32_EXT1, 59 STM32_EXT2, 60 STM32_EXT3, 61 STM32_EXT4, 62 STM32_EXT5, 63 STM32_EXT6, 64 STM32_EXT7, 65 STM32_EXT8, 66 STM32_EXT9, 67 STM32_EXT10, 68 STM32_EXT11, 69 STM32_EXT12, 70 STM32_EXT13, 71 STM32_EXT14, 72 STM32_EXT15, 73 STM32_EXT16, 74 STM32_EXT17, 75 STM32_EXT18, 76 STM32_EXT19, 77 STM32_EXT20, 78 }; 79 80 /** 81 * struct stm32_adc_trig_info - ADC trigger info 82 * @name: name of the trigger, corresponding to its source 83 * @extsel: trigger selection 84 */ 85 struct stm32_adc_trig_info { 86 const char *name; 87 enum stm32_adc_extsel extsel; 88 }; 89 90 /** 91 * struct stm32_adc_calib - optional adc calibration data 92 * @calfact_s: Calibration offset for single ended channels 93 * @calfact_d: Calibration offset in differential 94 * @lincalfact: Linearity calibration factor 95 * @calibrated: Indicates calibration status 96 */ 97 struct stm32_adc_calib { 98 u32 calfact_s; 99 u32 calfact_d; 100 u32 lincalfact[STM32H7_LINCALFACT_NUM]; 101 bool calibrated; 102 }; 103 104 /** 105 * struct stm32_adc_regs - stm32 ADC misc registers & bitfield desc 106 * @reg: register offset 107 * @mask: bitfield mask 108 * @shift: left shift 109 */ 110 struct stm32_adc_regs { 111 int reg; 112 int mask; 113 int shift; 114 }; 115 116 /** 117 * struct stm32_adc_regspec - stm32 registers definition 118 * @dr: data register offset 119 * @ier_eoc: interrupt enable register & eocie bitfield 120 * @ier_ovr: interrupt enable register & overrun bitfield 121 * @isr_eoc: interrupt status register & eoc bitfield 122 * @isr_ovr: interrupt status register & overrun bitfield 123 * @sqr: reference to sequence registers array 124 * @exten: trigger control register & bitfield 125 * @extsel: trigger selection register & bitfield 126 * @res: resolution selection register & bitfield 127 * @smpr: smpr1 & smpr2 registers offset array 128 * @smp_bits: smpr1 & smpr2 index and bitfields 129 */ 130 struct stm32_adc_regspec { 131 const u32 dr; 132 const struct stm32_adc_regs ier_eoc; 133 const struct stm32_adc_regs ier_ovr; 134 const struct stm32_adc_regs isr_eoc; 135 const struct stm32_adc_regs isr_ovr; 136 const struct stm32_adc_regs *sqr; 137 const struct stm32_adc_regs exten; 138 const struct stm32_adc_regs extsel; 139 const struct stm32_adc_regs res; 140 const u32 smpr[2]; 141 const struct stm32_adc_regs *smp_bits; 142 }; 143 144 struct stm32_adc; 145 146 /** 147 * struct stm32_adc_cfg - stm32 compatible configuration data 148 * @regs: registers descriptions 149 * @adc_info: per instance input channels definitions 150 * @trigs: external trigger sources 151 * @clk_required: clock is required 152 * @has_vregready: vregready status flag presence 153 * @prepare: optional prepare routine (power-up, enable) 154 * @start_conv: routine to start conversions 155 * @stop_conv: routine to stop conversions 156 * @unprepare: optional unprepare routine (disable, power-down) 157 * @irq_clear: routine to clear irqs 158 * @smp_cycles: programmable sampling time (ADC clock cycles) 159 */ 160 struct stm32_adc_cfg { 161 const struct stm32_adc_regspec *regs; 162 const struct stm32_adc_info *adc_info; 163 struct stm32_adc_trig_info *trigs; 164 bool clk_required; 165 bool has_vregready; 166 int (*prepare)(struct iio_dev *); 167 void (*start_conv)(struct iio_dev *, bool dma); 168 void (*stop_conv)(struct iio_dev *); 169 void (*unprepare)(struct iio_dev *); 170 void (*irq_clear)(struct iio_dev *indio_dev, u32 msk); 171 const unsigned int *smp_cycles; 172 }; 173 174 /** 175 * struct stm32_adc - private data of each ADC IIO instance 176 * @common: reference to ADC block common data 177 * @offset: ADC instance register offset in ADC block 178 * @cfg: compatible configuration data 179 * @completion: end of single conversion completion 180 * @buffer: data buffer + 8 bytes for timestamp if enabled 181 * @clk: clock for this adc instance 182 * @irq: interrupt for this adc instance 183 * @lock: spinlock 184 * @bufi: data buffer index 185 * @num_conv: expected number of scan conversions 186 * @res: data resolution (e.g. RES bitfield value) 187 * @trigger_polarity: external trigger polarity (e.g. exten) 188 * @dma_chan: dma channel 189 * @rx_buf: dma rx buffer cpu address 190 * @rx_dma_buf: dma rx buffer bus address 191 * @rx_buf_sz: dma rx buffer size 192 * @difsel: bitmask to set single-ended/differential channel 193 * @pcsel: bitmask to preselect channels on some devices 194 * @smpr_val: sampling time settings (e.g. smpr1 / smpr2) 195 * @cal: optional calibration data on some devices 196 * @chan_name: channel name array 197 */ 198 struct stm32_adc { 199 struct stm32_adc_common *common; 200 u32 offset; 201 const struct stm32_adc_cfg *cfg; 202 struct completion completion; 203 u16 buffer[STM32_ADC_MAX_SQ + 4] __aligned(8); 204 struct clk *clk; 205 int irq; 206 spinlock_t lock; /* interrupt lock */ 207 unsigned int bufi; 208 unsigned int num_conv; 209 u32 res; 210 u32 trigger_polarity; 211 struct dma_chan *dma_chan; 212 u8 *rx_buf; 213 dma_addr_t rx_dma_buf; 214 unsigned int rx_buf_sz; 215 u32 difsel; 216 u32 pcsel; 217 u32 smpr_val[2]; 218 struct stm32_adc_calib cal; 219 char chan_name[STM32_ADC_CH_MAX][STM32_ADC_CH_SZ]; 220 }; 221 222 struct stm32_adc_diff_channel { 223 u32 vinp; 224 u32 vinn; 225 }; 226 227 /** 228 * struct stm32_adc_info - stm32 ADC, per instance config data 229 * @max_channels: Number of channels 230 * @resolutions: available resolutions 231 * @num_res: number of available resolutions 232 */ 233 struct stm32_adc_info { 234 int max_channels; 235 const unsigned int *resolutions; 236 const unsigned int num_res; 237 }; 238 239 static const unsigned int stm32f4_adc_resolutions[] = { 240 /* sorted values so the index matches RES[1:0] in STM32F4_ADC_CR1 */ 241 12, 10, 8, 6, 242 }; 243 244 /* stm32f4 can have up to 16 channels */ 245 static const struct stm32_adc_info stm32f4_adc_info = { 246 .max_channels = 16, 247 .resolutions = stm32f4_adc_resolutions, 248 .num_res = ARRAY_SIZE(stm32f4_adc_resolutions), 249 }; 250 251 static const unsigned int stm32h7_adc_resolutions[] = { 252 /* sorted values so the index matches RES[2:0] in STM32H7_ADC_CFGR */ 253 16, 14, 12, 10, 8, 254 }; 255 256 /* stm32h7 can have up to 20 channels */ 257 static const struct stm32_adc_info stm32h7_adc_info = { 258 .max_channels = STM32_ADC_CH_MAX, 259 .resolutions = stm32h7_adc_resolutions, 260 .num_res = ARRAY_SIZE(stm32h7_adc_resolutions), 261 }; 262 263 /* 264 * stm32f4_sq - describe regular sequence registers 265 * - L: sequence len (register & bit field) 266 * - SQ1..SQ16: sequence entries (register & bit field) 267 */ 268 static const struct stm32_adc_regs stm32f4_sq[STM32_ADC_MAX_SQ + 1] = { 269 /* L: len bit field description to be kept as first element */ 270 { STM32F4_ADC_SQR1, GENMASK(23, 20), 20 }, 271 /* SQ1..SQ16 registers & bit fields (reg, mask, shift) */ 272 { STM32F4_ADC_SQR3, GENMASK(4, 0), 0 }, 273 { STM32F4_ADC_SQR3, GENMASK(9, 5), 5 }, 274 { STM32F4_ADC_SQR3, GENMASK(14, 10), 10 }, 275 { STM32F4_ADC_SQR3, GENMASK(19, 15), 15 }, 276 { STM32F4_ADC_SQR3, GENMASK(24, 20), 20 }, 277 { STM32F4_ADC_SQR3, GENMASK(29, 25), 25 }, 278 { STM32F4_ADC_SQR2, GENMASK(4, 0), 0 }, 279 { STM32F4_ADC_SQR2, GENMASK(9, 5), 5 }, 280 { STM32F4_ADC_SQR2, GENMASK(14, 10), 10 }, 281 { STM32F4_ADC_SQR2, GENMASK(19, 15), 15 }, 282 { STM32F4_ADC_SQR2, GENMASK(24, 20), 20 }, 283 { STM32F4_ADC_SQR2, GENMASK(29, 25), 25 }, 284 { STM32F4_ADC_SQR1, GENMASK(4, 0), 0 }, 285 { STM32F4_ADC_SQR1, GENMASK(9, 5), 5 }, 286 { STM32F4_ADC_SQR1, GENMASK(14, 10), 10 }, 287 { STM32F4_ADC_SQR1, GENMASK(19, 15), 15 }, 288 }; 289 290 /* STM32F4 external trigger sources for all instances */ 291 static struct stm32_adc_trig_info stm32f4_adc_trigs[] = { 292 { TIM1_CH1, STM32_EXT0 }, 293 { TIM1_CH2, STM32_EXT1 }, 294 { TIM1_CH3, STM32_EXT2 }, 295 { TIM2_CH2, STM32_EXT3 }, 296 { TIM2_CH3, STM32_EXT4 }, 297 { TIM2_CH4, STM32_EXT5 }, 298 { TIM2_TRGO, STM32_EXT6 }, 299 { TIM3_CH1, STM32_EXT7 }, 300 { TIM3_TRGO, STM32_EXT8 }, 301 { TIM4_CH4, STM32_EXT9 }, 302 { TIM5_CH1, STM32_EXT10 }, 303 { TIM5_CH2, STM32_EXT11 }, 304 { TIM5_CH3, STM32_EXT12 }, 305 { TIM8_CH1, STM32_EXT13 }, 306 { TIM8_TRGO, STM32_EXT14 }, 307 {}, /* sentinel */ 308 }; 309 310 /* 311 * stm32f4_smp_bits[] - describe sampling time register index & bit fields 312 * Sorted so it can be indexed by channel number. 313 */ 314 static const struct stm32_adc_regs stm32f4_smp_bits[] = { 315 /* STM32F4_ADC_SMPR2: smpr[] index, mask, shift for SMP0 to SMP9 */ 316 { 1, GENMASK(2, 0), 0 }, 317 { 1, GENMASK(5, 3), 3 }, 318 { 1, GENMASK(8, 6), 6 }, 319 { 1, GENMASK(11, 9), 9 }, 320 { 1, GENMASK(14, 12), 12 }, 321 { 1, GENMASK(17, 15), 15 }, 322 { 1, GENMASK(20, 18), 18 }, 323 { 1, GENMASK(23, 21), 21 }, 324 { 1, GENMASK(26, 24), 24 }, 325 { 1, GENMASK(29, 27), 27 }, 326 /* STM32F4_ADC_SMPR1, smpr[] index, mask, shift for SMP10 to SMP18 */ 327 { 0, GENMASK(2, 0), 0 }, 328 { 0, GENMASK(5, 3), 3 }, 329 { 0, GENMASK(8, 6), 6 }, 330 { 0, GENMASK(11, 9), 9 }, 331 { 0, GENMASK(14, 12), 12 }, 332 { 0, GENMASK(17, 15), 15 }, 333 { 0, GENMASK(20, 18), 18 }, 334 { 0, GENMASK(23, 21), 21 }, 335 { 0, GENMASK(26, 24), 24 }, 336 }; 337 338 /* STM32F4 programmable sampling time (ADC clock cycles) */ 339 static const unsigned int stm32f4_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = { 340 3, 15, 28, 56, 84, 112, 144, 480, 341 }; 342 343 static const struct stm32_adc_regspec stm32f4_adc_regspec = { 344 .dr = STM32F4_ADC_DR, 345 .ier_eoc = { STM32F4_ADC_CR1, STM32F4_EOCIE }, 346 .ier_ovr = { STM32F4_ADC_CR1, STM32F4_OVRIE }, 347 .isr_eoc = { STM32F4_ADC_SR, STM32F4_EOC }, 348 .isr_ovr = { STM32F4_ADC_SR, STM32F4_OVR }, 349 .sqr = stm32f4_sq, 350 .exten = { STM32F4_ADC_CR2, STM32F4_EXTEN_MASK, STM32F4_EXTEN_SHIFT }, 351 .extsel = { STM32F4_ADC_CR2, STM32F4_EXTSEL_MASK, 352 STM32F4_EXTSEL_SHIFT }, 353 .res = { STM32F4_ADC_CR1, STM32F4_RES_MASK, STM32F4_RES_SHIFT }, 354 .smpr = { STM32F4_ADC_SMPR1, STM32F4_ADC_SMPR2 }, 355 .smp_bits = stm32f4_smp_bits, 356 }; 357 358 static const struct stm32_adc_regs stm32h7_sq[STM32_ADC_MAX_SQ + 1] = { 359 /* L: len bit field description to be kept as first element */ 360 { STM32H7_ADC_SQR1, GENMASK(3, 0), 0 }, 361 /* SQ1..SQ16 registers & bit fields (reg, mask, shift) */ 362 { STM32H7_ADC_SQR1, GENMASK(10, 6), 6 }, 363 { STM32H7_ADC_SQR1, GENMASK(16, 12), 12 }, 364 { STM32H7_ADC_SQR1, GENMASK(22, 18), 18 }, 365 { STM32H7_ADC_SQR1, GENMASK(28, 24), 24 }, 366 { STM32H7_ADC_SQR2, GENMASK(4, 0), 0 }, 367 { STM32H7_ADC_SQR2, GENMASK(10, 6), 6 }, 368 { STM32H7_ADC_SQR2, GENMASK(16, 12), 12 }, 369 { STM32H7_ADC_SQR2, GENMASK(22, 18), 18 }, 370 { STM32H7_ADC_SQR2, GENMASK(28, 24), 24 }, 371 { STM32H7_ADC_SQR3, GENMASK(4, 0), 0 }, 372 { STM32H7_ADC_SQR3, GENMASK(10, 6), 6 }, 373 { STM32H7_ADC_SQR3, GENMASK(16, 12), 12 }, 374 { STM32H7_ADC_SQR3, GENMASK(22, 18), 18 }, 375 { STM32H7_ADC_SQR3, GENMASK(28, 24), 24 }, 376 { STM32H7_ADC_SQR4, GENMASK(4, 0), 0 }, 377 { STM32H7_ADC_SQR4, GENMASK(10, 6), 6 }, 378 }; 379 380 /* STM32H7 external trigger sources for all instances */ 381 static struct stm32_adc_trig_info stm32h7_adc_trigs[] = { 382 { TIM1_CH1, STM32_EXT0 }, 383 { TIM1_CH2, STM32_EXT1 }, 384 { TIM1_CH3, STM32_EXT2 }, 385 { TIM2_CH2, STM32_EXT3 }, 386 { TIM3_TRGO, STM32_EXT4 }, 387 { TIM4_CH4, STM32_EXT5 }, 388 { TIM8_TRGO, STM32_EXT7 }, 389 { TIM8_TRGO2, STM32_EXT8 }, 390 { TIM1_TRGO, STM32_EXT9 }, 391 { TIM1_TRGO2, STM32_EXT10 }, 392 { TIM2_TRGO, STM32_EXT11 }, 393 { TIM4_TRGO, STM32_EXT12 }, 394 { TIM6_TRGO, STM32_EXT13 }, 395 { TIM15_TRGO, STM32_EXT14 }, 396 { TIM3_CH4, STM32_EXT15 }, 397 { LPTIM1_OUT, STM32_EXT18 }, 398 { LPTIM2_OUT, STM32_EXT19 }, 399 { LPTIM3_OUT, STM32_EXT20 }, 400 {}, 401 }; 402 403 /* 404 * stm32h7_smp_bits - describe sampling time register index & bit fields 405 * Sorted so it can be indexed by channel number. 406 */ 407 static const struct stm32_adc_regs stm32h7_smp_bits[] = { 408 /* STM32H7_ADC_SMPR1, smpr[] index, mask, shift for SMP0 to SMP9 */ 409 { 0, GENMASK(2, 0), 0 }, 410 { 0, GENMASK(5, 3), 3 }, 411 { 0, GENMASK(8, 6), 6 }, 412 { 0, GENMASK(11, 9), 9 }, 413 { 0, GENMASK(14, 12), 12 }, 414 { 0, GENMASK(17, 15), 15 }, 415 { 0, GENMASK(20, 18), 18 }, 416 { 0, GENMASK(23, 21), 21 }, 417 { 0, GENMASK(26, 24), 24 }, 418 { 0, GENMASK(29, 27), 27 }, 419 /* STM32H7_ADC_SMPR2, smpr[] index, mask, shift for SMP10 to SMP19 */ 420 { 1, GENMASK(2, 0), 0 }, 421 { 1, GENMASK(5, 3), 3 }, 422 { 1, GENMASK(8, 6), 6 }, 423 { 1, GENMASK(11, 9), 9 }, 424 { 1, GENMASK(14, 12), 12 }, 425 { 1, GENMASK(17, 15), 15 }, 426 { 1, GENMASK(20, 18), 18 }, 427 { 1, GENMASK(23, 21), 21 }, 428 { 1, GENMASK(26, 24), 24 }, 429 { 1, GENMASK(29, 27), 27 }, 430 }; 431 432 /* STM32H7 programmable sampling time (ADC clock cycles, rounded down) */ 433 static const unsigned int stm32h7_adc_smp_cycles[STM32_ADC_MAX_SMP + 1] = { 434 1, 2, 8, 16, 32, 64, 387, 810, 435 }; 436 437 static const struct stm32_adc_regspec stm32h7_adc_regspec = { 438 .dr = STM32H7_ADC_DR, 439 .ier_eoc = { STM32H7_ADC_IER, STM32H7_EOCIE }, 440 .ier_ovr = { STM32H7_ADC_IER, STM32H7_OVRIE }, 441 .isr_eoc = { STM32H7_ADC_ISR, STM32H7_EOC }, 442 .isr_ovr = { STM32H7_ADC_ISR, STM32H7_OVR }, 443 .sqr = stm32h7_sq, 444 .exten = { STM32H7_ADC_CFGR, STM32H7_EXTEN_MASK, STM32H7_EXTEN_SHIFT }, 445 .extsel = { STM32H7_ADC_CFGR, STM32H7_EXTSEL_MASK, 446 STM32H7_EXTSEL_SHIFT }, 447 .res = { STM32H7_ADC_CFGR, STM32H7_RES_MASK, STM32H7_RES_SHIFT }, 448 .smpr = { STM32H7_ADC_SMPR1, STM32H7_ADC_SMPR2 }, 449 .smp_bits = stm32h7_smp_bits, 450 }; 451 452 /* 453 * STM32 ADC registers access routines 454 * @adc: stm32 adc instance 455 * @reg: reg offset in adc instance 456 * 457 * Note: All instances share same base, with 0x0, 0x100 or 0x200 offset resp. 458 * for adc1, adc2 and adc3. 459 */ 460 static u32 stm32_adc_readl(struct stm32_adc *adc, u32 reg) 461 { 462 return readl_relaxed(adc->common->base + adc->offset + reg); 463 } 464 465 #define stm32_adc_readl_addr(addr) stm32_adc_readl(adc, addr) 466 467 #define stm32_adc_readl_poll_timeout(reg, val, cond, sleep_us, timeout_us) \ 468 readx_poll_timeout(stm32_adc_readl_addr, reg, val, \ 469 cond, sleep_us, timeout_us) 470 471 static u16 stm32_adc_readw(struct stm32_adc *adc, u32 reg) 472 { 473 return readw_relaxed(adc->common->base + adc->offset + reg); 474 } 475 476 static void stm32_adc_writel(struct stm32_adc *adc, u32 reg, u32 val) 477 { 478 writel_relaxed(val, adc->common->base + adc->offset + reg); 479 } 480 481 static void stm32_adc_set_bits(struct stm32_adc *adc, u32 reg, u32 bits) 482 { 483 unsigned long flags; 484 485 spin_lock_irqsave(&adc->lock, flags); 486 stm32_adc_writel(adc, reg, stm32_adc_readl(adc, reg) | bits); 487 spin_unlock_irqrestore(&adc->lock, flags); 488 } 489 490 static void stm32_adc_clr_bits(struct stm32_adc *adc, u32 reg, u32 bits) 491 { 492 unsigned long flags; 493 494 spin_lock_irqsave(&adc->lock, flags); 495 stm32_adc_writel(adc, reg, stm32_adc_readl(adc, reg) & ~bits); 496 spin_unlock_irqrestore(&adc->lock, flags); 497 } 498 499 /** 500 * stm32_adc_conv_irq_enable() - Enable end of conversion interrupt 501 * @adc: stm32 adc instance 502 */ 503 static void stm32_adc_conv_irq_enable(struct stm32_adc *adc) 504 { 505 stm32_adc_set_bits(adc, adc->cfg->regs->ier_eoc.reg, 506 adc->cfg->regs->ier_eoc.mask); 507 }; 508 509 /** 510 * stm32_adc_conv_irq_disable() - Disable end of conversion interrupt 511 * @adc: stm32 adc instance 512 */ 513 static void stm32_adc_conv_irq_disable(struct stm32_adc *adc) 514 { 515 stm32_adc_clr_bits(adc, adc->cfg->regs->ier_eoc.reg, 516 adc->cfg->regs->ier_eoc.mask); 517 } 518 519 static void stm32_adc_ovr_irq_enable(struct stm32_adc *adc) 520 { 521 stm32_adc_set_bits(adc, adc->cfg->regs->ier_ovr.reg, 522 adc->cfg->regs->ier_ovr.mask); 523 } 524 525 static void stm32_adc_ovr_irq_disable(struct stm32_adc *adc) 526 { 527 stm32_adc_clr_bits(adc, adc->cfg->regs->ier_ovr.reg, 528 adc->cfg->regs->ier_ovr.mask); 529 } 530 531 static void stm32_adc_set_res(struct stm32_adc *adc) 532 { 533 const struct stm32_adc_regs *res = &adc->cfg->regs->res; 534 u32 val; 535 536 val = stm32_adc_readl(adc, res->reg); 537 val = (val & ~res->mask) | (adc->res << res->shift); 538 stm32_adc_writel(adc, res->reg, val); 539 } 540 541 static int stm32_adc_hw_stop(struct device *dev) 542 { 543 struct iio_dev *indio_dev = dev_get_drvdata(dev); 544 struct stm32_adc *adc = iio_priv(indio_dev); 545 546 if (adc->cfg->unprepare) 547 adc->cfg->unprepare(indio_dev); 548 549 clk_disable_unprepare(adc->clk); 550 551 return 0; 552 } 553 554 static int stm32_adc_hw_start(struct device *dev) 555 { 556 struct iio_dev *indio_dev = dev_get_drvdata(dev); 557 struct stm32_adc *adc = iio_priv(indio_dev); 558 int ret; 559 560 ret = clk_prepare_enable(adc->clk); 561 if (ret) 562 return ret; 563 564 stm32_adc_set_res(adc); 565 566 if (adc->cfg->prepare) { 567 ret = adc->cfg->prepare(indio_dev); 568 if (ret) 569 goto err_clk_dis; 570 } 571 572 return 0; 573 574 err_clk_dis: 575 clk_disable_unprepare(adc->clk); 576 577 return ret; 578 } 579 580 /** 581 * stm32f4_adc_start_conv() - Start conversions for regular channels. 582 * @indio_dev: IIO device instance 583 * @dma: use dma to transfer conversion result 584 * 585 * Start conversions for regular channels. 586 * Also take care of normal or DMA mode. Circular DMA may be used for regular 587 * conversions, in IIO buffer modes. Otherwise, use ADC interrupt with direct 588 * DR read instead (e.g. read_raw, or triggered buffer mode without DMA). 589 */ 590 static void stm32f4_adc_start_conv(struct iio_dev *indio_dev, bool dma) 591 { 592 struct stm32_adc *adc = iio_priv(indio_dev); 593 594 stm32_adc_set_bits(adc, STM32F4_ADC_CR1, STM32F4_SCAN); 595 596 if (dma) 597 stm32_adc_set_bits(adc, STM32F4_ADC_CR2, 598 STM32F4_DMA | STM32F4_DDS); 599 600 stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_EOCS | STM32F4_ADON); 601 602 /* Wait for Power-up time (tSTAB from datasheet) */ 603 usleep_range(2, 3); 604 605 /* Software start ? (e.g. trigger detection disabled ?) */ 606 if (!(stm32_adc_readl(adc, STM32F4_ADC_CR2) & STM32F4_EXTEN_MASK)) 607 stm32_adc_set_bits(adc, STM32F4_ADC_CR2, STM32F4_SWSTART); 608 } 609 610 static void stm32f4_adc_stop_conv(struct iio_dev *indio_dev) 611 { 612 struct stm32_adc *adc = iio_priv(indio_dev); 613 614 stm32_adc_clr_bits(adc, STM32F4_ADC_CR2, STM32F4_EXTEN_MASK); 615 stm32_adc_clr_bits(adc, STM32F4_ADC_SR, STM32F4_STRT); 616 617 stm32_adc_clr_bits(adc, STM32F4_ADC_CR1, STM32F4_SCAN); 618 stm32_adc_clr_bits(adc, STM32F4_ADC_CR2, 619 STM32F4_ADON | STM32F4_DMA | STM32F4_DDS); 620 } 621 622 static void stm32f4_adc_irq_clear(struct iio_dev *indio_dev, u32 msk) 623 { 624 struct stm32_adc *adc = iio_priv(indio_dev); 625 626 stm32_adc_clr_bits(adc, adc->cfg->regs->isr_eoc.reg, msk); 627 } 628 629 static void stm32h7_adc_start_conv(struct iio_dev *indio_dev, bool dma) 630 { 631 struct stm32_adc *adc = iio_priv(indio_dev); 632 enum stm32h7_adc_dmngt dmngt; 633 unsigned long flags; 634 u32 val; 635 636 if (dma) 637 dmngt = STM32H7_DMNGT_DMA_CIRC; 638 else 639 dmngt = STM32H7_DMNGT_DR_ONLY; 640 641 spin_lock_irqsave(&adc->lock, flags); 642 val = stm32_adc_readl(adc, STM32H7_ADC_CFGR); 643 val = (val & ~STM32H7_DMNGT_MASK) | (dmngt << STM32H7_DMNGT_SHIFT); 644 stm32_adc_writel(adc, STM32H7_ADC_CFGR, val); 645 spin_unlock_irqrestore(&adc->lock, flags); 646 647 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADSTART); 648 } 649 650 static void stm32h7_adc_stop_conv(struct iio_dev *indio_dev) 651 { 652 struct stm32_adc *adc = iio_priv(indio_dev); 653 int ret; 654 u32 val; 655 656 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADSTP); 657 658 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, 659 !(val & (STM32H7_ADSTART)), 660 100, STM32_ADC_TIMEOUT_US); 661 if (ret) 662 dev_warn(&indio_dev->dev, "stop failed\n"); 663 664 stm32_adc_clr_bits(adc, STM32H7_ADC_CFGR, STM32H7_DMNGT_MASK); 665 } 666 667 static void stm32h7_adc_irq_clear(struct iio_dev *indio_dev, u32 msk) 668 { 669 struct stm32_adc *adc = iio_priv(indio_dev); 670 /* On STM32H7 IRQs are cleared by writing 1 into ISR register */ 671 stm32_adc_set_bits(adc, adc->cfg->regs->isr_eoc.reg, msk); 672 } 673 674 static int stm32h7_adc_exit_pwr_down(struct iio_dev *indio_dev) 675 { 676 struct stm32_adc *adc = iio_priv(indio_dev); 677 int ret; 678 u32 val; 679 680 /* Exit deep power down, then enable ADC voltage regulator */ 681 stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD); 682 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADVREGEN); 683 684 if (adc->common->rate > STM32H7_BOOST_CLKRATE) 685 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_BOOST); 686 687 /* Wait for startup time */ 688 if (!adc->cfg->has_vregready) { 689 usleep_range(10, 20); 690 return 0; 691 } 692 693 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_ISR, val, 694 val & STM32MP1_VREGREADY, 100, 695 STM32_ADC_TIMEOUT_US); 696 if (ret) { 697 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD); 698 dev_err(&indio_dev->dev, "Failed to exit power down\n"); 699 } 700 701 return ret; 702 } 703 704 static void stm32h7_adc_enter_pwr_down(struct stm32_adc *adc) 705 { 706 stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_BOOST); 707 708 /* Setting DEEPPWD disables ADC vreg and clears ADVREGEN */ 709 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_DEEPPWD); 710 } 711 712 static int stm32h7_adc_enable(struct iio_dev *indio_dev) 713 { 714 struct stm32_adc *adc = iio_priv(indio_dev); 715 int ret; 716 u32 val; 717 718 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADEN); 719 720 /* Poll for ADRDY to be set (after adc startup time) */ 721 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_ISR, val, 722 val & STM32H7_ADRDY, 723 100, STM32_ADC_TIMEOUT_US); 724 if (ret) { 725 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADDIS); 726 dev_err(&indio_dev->dev, "Failed to enable ADC\n"); 727 } else { 728 /* Clear ADRDY by writing one */ 729 stm32_adc_set_bits(adc, STM32H7_ADC_ISR, STM32H7_ADRDY); 730 } 731 732 return ret; 733 } 734 735 static void stm32h7_adc_disable(struct iio_dev *indio_dev) 736 { 737 struct stm32_adc *adc = iio_priv(indio_dev); 738 int ret; 739 u32 val; 740 741 /* Disable ADC and wait until it's effectively disabled */ 742 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADDIS); 743 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, 744 !(val & STM32H7_ADEN), 100, 745 STM32_ADC_TIMEOUT_US); 746 if (ret) 747 dev_warn(&indio_dev->dev, "Failed to disable\n"); 748 } 749 750 /** 751 * stm32h7_adc_read_selfcalib() - read calibration shadow regs, save result 752 * @indio_dev: IIO device instance 753 * Note: Must be called once ADC is enabled, so LINCALRDYW[1..6] are writable 754 */ 755 static int stm32h7_adc_read_selfcalib(struct iio_dev *indio_dev) 756 { 757 struct stm32_adc *adc = iio_priv(indio_dev); 758 int i, ret; 759 u32 lincalrdyw_mask, val; 760 761 /* Read linearity calibration */ 762 lincalrdyw_mask = STM32H7_LINCALRDYW6; 763 for (i = STM32H7_LINCALFACT_NUM - 1; i >= 0; i--) { 764 /* Clear STM32H7_LINCALRDYW[6..1]: transfer calib to CALFACT2 */ 765 stm32_adc_clr_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask); 766 767 /* Poll: wait calib data to be ready in CALFACT2 register */ 768 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, 769 !(val & lincalrdyw_mask), 770 100, STM32_ADC_TIMEOUT_US); 771 if (ret) { 772 dev_err(&indio_dev->dev, "Failed to read calfact\n"); 773 return ret; 774 } 775 776 val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT2); 777 adc->cal.lincalfact[i] = (val & STM32H7_LINCALFACT_MASK); 778 adc->cal.lincalfact[i] >>= STM32H7_LINCALFACT_SHIFT; 779 780 lincalrdyw_mask >>= 1; 781 } 782 783 /* Read offset calibration */ 784 val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT); 785 adc->cal.calfact_s = (val & STM32H7_CALFACT_S_MASK); 786 adc->cal.calfact_s >>= STM32H7_CALFACT_S_SHIFT; 787 adc->cal.calfact_d = (val & STM32H7_CALFACT_D_MASK); 788 adc->cal.calfact_d >>= STM32H7_CALFACT_D_SHIFT; 789 adc->cal.calibrated = true; 790 791 return 0; 792 } 793 794 /** 795 * stm32h7_adc_restore_selfcalib() - Restore saved self-calibration result 796 * @indio_dev: IIO device instance 797 * Note: ADC must be enabled, with no on-going conversions. 798 */ 799 static int stm32h7_adc_restore_selfcalib(struct iio_dev *indio_dev) 800 { 801 struct stm32_adc *adc = iio_priv(indio_dev); 802 int i, ret; 803 u32 lincalrdyw_mask, val; 804 805 val = (adc->cal.calfact_s << STM32H7_CALFACT_S_SHIFT) | 806 (adc->cal.calfact_d << STM32H7_CALFACT_D_SHIFT); 807 stm32_adc_writel(adc, STM32H7_ADC_CALFACT, val); 808 809 lincalrdyw_mask = STM32H7_LINCALRDYW6; 810 for (i = STM32H7_LINCALFACT_NUM - 1; i >= 0; i--) { 811 /* 812 * Write saved calibration data to shadow registers: 813 * Write CALFACT2, and set LINCALRDYW[6..1] bit to trigger 814 * data write. Then poll to wait for complete transfer. 815 */ 816 val = adc->cal.lincalfact[i] << STM32H7_LINCALFACT_SHIFT; 817 stm32_adc_writel(adc, STM32H7_ADC_CALFACT2, val); 818 stm32_adc_set_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask); 819 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, 820 val & lincalrdyw_mask, 821 100, STM32_ADC_TIMEOUT_US); 822 if (ret) { 823 dev_err(&indio_dev->dev, "Failed to write calfact\n"); 824 return ret; 825 } 826 827 /* 828 * Read back calibration data, has two effects: 829 * - It ensures bits LINCALRDYW[6..1] are kept cleared 830 * for next time calibration needs to be restored. 831 * - BTW, bit clear triggers a read, then check data has been 832 * correctly written. 833 */ 834 stm32_adc_clr_bits(adc, STM32H7_ADC_CR, lincalrdyw_mask); 835 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, 836 !(val & lincalrdyw_mask), 837 100, STM32_ADC_TIMEOUT_US); 838 if (ret) { 839 dev_err(&indio_dev->dev, "Failed to read calfact\n"); 840 return ret; 841 } 842 val = stm32_adc_readl(adc, STM32H7_ADC_CALFACT2); 843 if (val != adc->cal.lincalfact[i] << STM32H7_LINCALFACT_SHIFT) { 844 dev_err(&indio_dev->dev, "calfact not consistent\n"); 845 return -EIO; 846 } 847 848 lincalrdyw_mask >>= 1; 849 } 850 851 return 0; 852 } 853 854 /* 855 * Fixed timeout value for ADC calibration. 856 * worst cases: 857 * - low clock frequency 858 * - maximum prescalers 859 * Calibration requires: 860 * - 131,072 ADC clock cycle for the linear calibration 861 * - 20 ADC clock cycle for the offset calibration 862 * 863 * Set to 100ms for now 864 */ 865 #define STM32H7_ADC_CALIB_TIMEOUT_US 100000 866 867 /** 868 * stm32h7_adc_selfcalib() - Procedure to calibrate ADC 869 * @indio_dev: IIO device instance 870 * Note: Must be called once ADC is out of power down. 871 */ 872 static int stm32h7_adc_selfcalib(struct iio_dev *indio_dev) 873 { 874 struct stm32_adc *adc = iio_priv(indio_dev); 875 int ret; 876 u32 val; 877 878 if (adc->cal.calibrated) 879 return true; 880 881 /* 882 * Select calibration mode: 883 * - Offset calibration for single ended inputs 884 * - No linearity calibration (do it later, before reading it) 885 */ 886 stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALDIF); 887 stm32_adc_clr_bits(adc, STM32H7_ADC_CR, STM32H7_ADCALLIN); 888 889 /* Start calibration, then wait for completion */ 890 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADCAL); 891 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, 892 !(val & STM32H7_ADCAL), 100, 893 STM32H7_ADC_CALIB_TIMEOUT_US); 894 if (ret) { 895 dev_err(&indio_dev->dev, "calibration failed\n"); 896 goto out; 897 } 898 899 /* 900 * Select calibration mode, then start calibration: 901 * - Offset calibration for differential input 902 * - Linearity calibration (needs to be done only once for single/diff) 903 * will run simultaneously with offset calibration. 904 */ 905 stm32_adc_set_bits(adc, STM32H7_ADC_CR, 906 STM32H7_ADCALDIF | STM32H7_ADCALLIN); 907 stm32_adc_set_bits(adc, STM32H7_ADC_CR, STM32H7_ADCAL); 908 ret = stm32_adc_readl_poll_timeout(STM32H7_ADC_CR, val, 909 !(val & STM32H7_ADCAL), 100, 910 STM32H7_ADC_CALIB_TIMEOUT_US); 911 if (ret) { 912 dev_err(&indio_dev->dev, "calibration failed\n"); 913 goto out; 914 } 915 916 out: 917 stm32_adc_clr_bits(adc, STM32H7_ADC_CR, 918 STM32H7_ADCALDIF | STM32H7_ADCALLIN); 919 920 return ret; 921 } 922 923 /** 924 * stm32h7_adc_prepare() - Leave power down mode to enable ADC. 925 * @indio_dev: IIO device instance 926 * Leave power down mode. 927 * Configure channels as single ended or differential before enabling ADC. 928 * Enable ADC. 929 * Restore calibration data. 930 * Pre-select channels that may be used in PCSEL (required by input MUX / IO): 931 * - Only one input is selected for single ended (e.g. 'vinp') 932 * - Two inputs are selected for differential channels (e.g. 'vinp' & 'vinn') 933 */ 934 static int stm32h7_adc_prepare(struct iio_dev *indio_dev) 935 { 936 struct stm32_adc *adc = iio_priv(indio_dev); 937 int calib, ret; 938 939 ret = stm32h7_adc_exit_pwr_down(indio_dev); 940 if (ret) 941 return ret; 942 943 ret = stm32h7_adc_selfcalib(indio_dev); 944 if (ret < 0) 945 goto pwr_dwn; 946 calib = ret; 947 948 stm32_adc_writel(adc, STM32H7_ADC_DIFSEL, adc->difsel); 949 950 ret = stm32h7_adc_enable(indio_dev); 951 if (ret) 952 goto pwr_dwn; 953 954 /* Either restore or read calibration result for future reference */ 955 if (calib) 956 ret = stm32h7_adc_restore_selfcalib(indio_dev); 957 else 958 ret = stm32h7_adc_read_selfcalib(indio_dev); 959 if (ret) 960 goto disable; 961 962 stm32_adc_writel(adc, STM32H7_ADC_PCSEL, adc->pcsel); 963 964 return 0; 965 966 disable: 967 stm32h7_adc_disable(indio_dev); 968 pwr_dwn: 969 stm32h7_adc_enter_pwr_down(adc); 970 971 return ret; 972 } 973 974 static void stm32h7_adc_unprepare(struct iio_dev *indio_dev) 975 { 976 struct stm32_adc *adc = iio_priv(indio_dev); 977 978 stm32h7_adc_disable(indio_dev); 979 stm32h7_adc_enter_pwr_down(adc); 980 } 981 982 /** 983 * stm32_adc_conf_scan_seq() - Build regular channels scan sequence 984 * @indio_dev: IIO device 985 * @scan_mask: channels to be converted 986 * 987 * Conversion sequence : 988 * Apply sampling time settings for all channels. 989 * Configure ADC scan sequence based on selected channels in scan_mask. 990 * Add channels to SQR registers, from scan_mask LSB to MSB, then 991 * program sequence len. 992 */ 993 static int stm32_adc_conf_scan_seq(struct iio_dev *indio_dev, 994 const unsigned long *scan_mask) 995 { 996 struct stm32_adc *adc = iio_priv(indio_dev); 997 const struct stm32_adc_regs *sqr = adc->cfg->regs->sqr; 998 const struct iio_chan_spec *chan; 999 u32 val, bit; 1000 int i = 0; 1001 1002 /* Apply sampling time settings */ 1003 stm32_adc_writel(adc, adc->cfg->regs->smpr[0], adc->smpr_val[0]); 1004 stm32_adc_writel(adc, adc->cfg->regs->smpr[1], adc->smpr_val[1]); 1005 1006 for_each_set_bit(bit, scan_mask, indio_dev->masklength) { 1007 chan = indio_dev->channels + bit; 1008 /* 1009 * Assign one channel per SQ entry in regular 1010 * sequence, starting with SQ1. 1011 */ 1012 i++; 1013 if (i > STM32_ADC_MAX_SQ) 1014 return -EINVAL; 1015 1016 dev_dbg(&indio_dev->dev, "%s chan %d to SQ%d\n", 1017 __func__, chan->channel, i); 1018 1019 val = stm32_adc_readl(adc, sqr[i].reg); 1020 val &= ~sqr[i].mask; 1021 val |= chan->channel << sqr[i].shift; 1022 stm32_adc_writel(adc, sqr[i].reg, val); 1023 } 1024 1025 if (!i) 1026 return -EINVAL; 1027 1028 /* Sequence len */ 1029 val = stm32_adc_readl(adc, sqr[0].reg); 1030 val &= ~sqr[0].mask; 1031 val |= ((i - 1) << sqr[0].shift); 1032 stm32_adc_writel(adc, sqr[0].reg, val); 1033 1034 return 0; 1035 } 1036 1037 /** 1038 * stm32_adc_get_trig_extsel() - Get external trigger selection 1039 * @indio_dev: IIO device structure 1040 * @trig: trigger 1041 * 1042 * Returns trigger extsel value, if trig matches, -EINVAL otherwise. 1043 */ 1044 static int stm32_adc_get_trig_extsel(struct iio_dev *indio_dev, 1045 struct iio_trigger *trig) 1046 { 1047 struct stm32_adc *adc = iio_priv(indio_dev); 1048 int i; 1049 1050 /* lookup triggers registered by stm32 timer trigger driver */ 1051 for (i = 0; adc->cfg->trigs[i].name; i++) { 1052 /** 1053 * Checking both stm32 timer trigger type and trig name 1054 * should be safe against arbitrary trigger names. 1055 */ 1056 if ((is_stm32_timer_trigger(trig) || 1057 is_stm32_lptim_trigger(trig)) && 1058 !strcmp(adc->cfg->trigs[i].name, trig->name)) { 1059 return adc->cfg->trigs[i].extsel; 1060 } 1061 } 1062 1063 return -EINVAL; 1064 } 1065 1066 /** 1067 * stm32_adc_set_trig() - Set a regular trigger 1068 * @indio_dev: IIO device 1069 * @trig: IIO trigger 1070 * 1071 * Set trigger source/polarity (e.g. SW, or HW with polarity) : 1072 * - if HW trigger disabled (e.g. trig == NULL, conversion launched by sw) 1073 * - if HW trigger enabled, set source & polarity 1074 */ 1075 static int stm32_adc_set_trig(struct iio_dev *indio_dev, 1076 struct iio_trigger *trig) 1077 { 1078 struct stm32_adc *adc = iio_priv(indio_dev); 1079 u32 val, extsel = 0, exten = STM32_EXTEN_SWTRIG; 1080 unsigned long flags; 1081 int ret; 1082 1083 if (trig) { 1084 ret = stm32_adc_get_trig_extsel(indio_dev, trig); 1085 if (ret < 0) 1086 return ret; 1087 1088 /* set trigger source and polarity (default to rising edge) */ 1089 extsel = ret; 1090 exten = adc->trigger_polarity + STM32_EXTEN_HWTRIG_RISING_EDGE; 1091 } 1092 1093 spin_lock_irqsave(&adc->lock, flags); 1094 val = stm32_adc_readl(adc, adc->cfg->regs->exten.reg); 1095 val &= ~(adc->cfg->regs->exten.mask | adc->cfg->regs->extsel.mask); 1096 val |= exten << adc->cfg->regs->exten.shift; 1097 val |= extsel << adc->cfg->regs->extsel.shift; 1098 stm32_adc_writel(adc, adc->cfg->regs->exten.reg, val); 1099 spin_unlock_irqrestore(&adc->lock, flags); 1100 1101 return 0; 1102 } 1103 1104 static int stm32_adc_set_trig_pol(struct iio_dev *indio_dev, 1105 const struct iio_chan_spec *chan, 1106 unsigned int type) 1107 { 1108 struct stm32_adc *adc = iio_priv(indio_dev); 1109 1110 adc->trigger_polarity = type; 1111 1112 return 0; 1113 } 1114 1115 static int stm32_adc_get_trig_pol(struct iio_dev *indio_dev, 1116 const struct iio_chan_spec *chan) 1117 { 1118 struct stm32_adc *adc = iio_priv(indio_dev); 1119 1120 return adc->trigger_polarity; 1121 } 1122 1123 static const char * const stm32_trig_pol_items[] = { 1124 "rising-edge", "falling-edge", "both-edges", 1125 }; 1126 1127 static const struct iio_enum stm32_adc_trig_pol = { 1128 .items = stm32_trig_pol_items, 1129 .num_items = ARRAY_SIZE(stm32_trig_pol_items), 1130 .get = stm32_adc_get_trig_pol, 1131 .set = stm32_adc_set_trig_pol, 1132 }; 1133 1134 /** 1135 * stm32_adc_single_conv() - Performs a single conversion 1136 * @indio_dev: IIO device 1137 * @chan: IIO channel 1138 * @res: conversion result 1139 * 1140 * The function performs a single conversion on a given channel: 1141 * - Apply sampling time settings 1142 * - Program sequencer with one channel (e.g. in SQ1 with len = 1) 1143 * - Use SW trigger 1144 * - Start conversion, then wait for interrupt completion. 1145 */ 1146 static int stm32_adc_single_conv(struct iio_dev *indio_dev, 1147 const struct iio_chan_spec *chan, 1148 int *res) 1149 { 1150 struct stm32_adc *adc = iio_priv(indio_dev); 1151 struct device *dev = indio_dev->dev.parent; 1152 const struct stm32_adc_regspec *regs = adc->cfg->regs; 1153 long timeout; 1154 u32 val; 1155 int ret; 1156 1157 reinit_completion(&adc->completion); 1158 1159 adc->bufi = 0; 1160 1161 ret = pm_runtime_resume_and_get(dev); 1162 if (ret < 0) 1163 return ret; 1164 1165 /* Apply sampling time settings */ 1166 stm32_adc_writel(adc, regs->smpr[0], adc->smpr_val[0]); 1167 stm32_adc_writel(adc, regs->smpr[1], adc->smpr_val[1]); 1168 1169 /* Program chan number in regular sequence (SQ1) */ 1170 val = stm32_adc_readl(adc, regs->sqr[1].reg); 1171 val &= ~regs->sqr[1].mask; 1172 val |= chan->channel << regs->sqr[1].shift; 1173 stm32_adc_writel(adc, regs->sqr[1].reg, val); 1174 1175 /* Set regular sequence len (0 for 1 conversion) */ 1176 stm32_adc_clr_bits(adc, regs->sqr[0].reg, regs->sqr[0].mask); 1177 1178 /* Trigger detection disabled (conversion can be launched in SW) */ 1179 stm32_adc_clr_bits(adc, regs->exten.reg, regs->exten.mask); 1180 1181 stm32_adc_conv_irq_enable(adc); 1182 1183 adc->cfg->start_conv(indio_dev, false); 1184 1185 timeout = wait_for_completion_interruptible_timeout( 1186 &adc->completion, STM32_ADC_TIMEOUT); 1187 if (timeout == 0) { 1188 ret = -ETIMEDOUT; 1189 } else if (timeout < 0) { 1190 ret = timeout; 1191 } else { 1192 *res = adc->buffer[0]; 1193 ret = IIO_VAL_INT; 1194 } 1195 1196 adc->cfg->stop_conv(indio_dev); 1197 1198 stm32_adc_conv_irq_disable(adc); 1199 1200 pm_runtime_mark_last_busy(dev); 1201 pm_runtime_put_autosuspend(dev); 1202 1203 return ret; 1204 } 1205 1206 static int stm32_adc_read_raw(struct iio_dev *indio_dev, 1207 struct iio_chan_spec const *chan, 1208 int *val, int *val2, long mask) 1209 { 1210 struct stm32_adc *adc = iio_priv(indio_dev); 1211 int ret; 1212 1213 switch (mask) { 1214 case IIO_CHAN_INFO_RAW: 1215 ret = iio_device_claim_direct_mode(indio_dev); 1216 if (ret) 1217 return ret; 1218 if (chan->type == IIO_VOLTAGE) 1219 ret = stm32_adc_single_conv(indio_dev, chan, val); 1220 else 1221 ret = -EINVAL; 1222 iio_device_release_direct_mode(indio_dev); 1223 return ret; 1224 1225 case IIO_CHAN_INFO_SCALE: 1226 if (chan->differential) { 1227 *val = adc->common->vref_mv * 2; 1228 *val2 = chan->scan_type.realbits; 1229 } else { 1230 *val = adc->common->vref_mv; 1231 *val2 = chan->scan_type.realbits; 1232 } 1233 return IIO_VAL_FRACTIONAL_LOG2; 1234 1235 case IIO_CHAN_INFO_OFFSET: 1236 if (chan->differential) 1237 /* ADC_full_scale / 2 */ 1238 *val = -((1 << chan->scan_type.realbits) / 2); 1239 else 1240 *val = 0; 1241 return IIO_VAL_INT; 1242 1243 default: 1244 return -EINVAL; 1245 } 1246 } 1247 1248 static void stm32_adc_irq_clear(struct iio_dev *indio_dev, u32 msk) 1249 { 1250 struct stm32_adc *adc = iio_priv(indio_dev); 1251 1252 adc->cfg->irq_clear(indio_dev, msk); 1253 } 1254 1255 static irqreturn_t stm32_adc_threaded_isr(int irq, void *data) 1256 { 1257 struct iio_dev *indio_dev = data; 1258 struct stm32_adc *adc = iio_priv(indio_dev); 1259 const struct stm32_adc_regspec *regs = adc->cfg->regs; 1260 u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg); 1261 u32 mask = stm32_adc_readl(adc, regs->ier_eoc.reg); 1262 1263 /* Check ovr status right now, as ovr mask should be already disabled */ 1264 if (status & regs->isr_ovr.mask) { 1265 /* 1266 * Clear ovr bit to avoid subsequent calls to IRQ handler. 1267 * This requires to stop ADC first. OVR bit state in ISR, 1268 * is propaged to CSR register by hardware. 1269 */ 1270 adc->cfg->stop_conv(indio_dev); 1271 stm32_adc_irq_clear(indio_dev, regs->isr_ovr.mask); 1272 dev_err(&indio_dev->dev, "Overrun, stopping: restart needed\n"); 1273 return IRQ_HANDLED; 1274 } 1275 1276 if (!(status & mask)) 1277 dev_err_ratelimited(&indio_dev->dev, 1278 "Unexpected IRQ: IER=0x%08x, ISR=0x%08x\n", 1279 mask, status); 1280 1281 return IRQ_NONE; 1282 } 1283 1284 static irqreturn_t stm32_adc_isr(int irq, void *data) 1285 { 1286 struct iio_dev *indio_dev = data; 1287 struct stm32_adc *adc = iio_priv(indio_dev); 1288 const struct stm32_adc_regspec *regs = adc->cfg->regs; 1289 u32 status = stm32_adc_readl(adc, regs->isr_eoc.reg); 1290 u32 mask = stm32_adc_readl(adc, regs->ier_eoc.reg); 1291 1292 if (!(status & mask)) 1293 return IRQ_WAKE_THREAD; 1294 1295 if (status & regs->isr_ovr.mask) { 1296 /* 1297 * Overrun occurred on regular conversions: data for wrong 1298 * channel may be read. Unconditionally disable interrupts 1299 * to stop processing data and print error message. 1300 * Restarting the capture can be done by disabling, then 1301 * re-enabling it (e.g. write 0, then 1 to buffer/enable). 1302 */ 1303 stm32_adc_ovr_irq_disable(adc); 1304 stm32_adc_conv_irq_disable(adc); 1305 return IRQ_WAKE_THREAD; 1306 } 1307 1308 if (status & regs->isr_eoc.mask) { 1309 /* Reading DR also clears EOC status flag */ 1310 adc->buffer[adc->bufi] = stm32_adc_readw(adc, regs->dr); 1311 if (iio_buffer_enabled(indio_dev)) { 1312 adc->bufi++; 1313 if (adc->bufi >= adc->num_conv) { 1314 stm32_adc_conv_irq_disable(adc); 1315 iio_trigger_poll(indio_dev->trig); 1316 } 1317 } else { 1318 complete(&adc->completion); 1319 } 1320 return IRQ_HANDLED; 1321 } 1322 1323 return IRQ_NONE; 1324 } 1325 1326 /** 1327 * stm32_adc_validate_trigger() - validate trigger for stm32 adc 1328 * @indio_dev: IIO device 1329 * @trig: new trigger 1330 * 1331 * Returns: 0 if trig matches one of the triggers registered by stm32 adc 1332 * driver, -EINVAL otherwise. 1333 */ 1334 static int stm32_adc_validate_trigger(struct iio_dev *indio_dev, 1335 struct iio_trigger *trig) 1336 { 1337 return stm32_adc_get_trig_extsel(indio_dev, trig) < 0 ? -EINVAL : 0; 1338 } 1339 1340 static int stm32_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val) 1341 { 1342 struct stm32_adc *adc = iio_priv(indio_dev); 1343 unsigned int watermark = STM32_DMA_BUFFER_SIZE / 2; 1344 unsigned int rx_buf_sz = STM32_DMA_BUFFER_SIZE; 1345 1346 /* 1347 * dma cyclic transfers are used, buffer is split into two periods. 1348 * There should be : 1349 * - always one buffer (period) dma is working on 1350 * - one buffer (period) driver can push data. 1351 */ 1352 watermark = min(watermark, val * (unsigned)(sizeof(u16))); 1353 adc->rx_buf_sz = min(rx_buf_sz, watermark * 2 * adc->num_conv); 1354 1355 return 0; 1356 } 1357 1358 static int stm32_adc_update_scan_mode(struct iio_dev *indio_dev, 1359 const unsigned long *scan_mask) 1360 { 1361 struct stm32_adc *adc = iio_priv(indio_dev); 1362 struct device *dev = indio_dev->dev.parent; 1363 int ret; 1364 1365 ret = pm_runtime_resume_and_get(dev); 1366 if (ret < 0) 1367 return ret; 1368 1369 adc->num_conv = bitmap_weight(scan_mask, indio_dev->masklength); 1370 1371 ret = stm32_adc_conf_scan_seq(indio_dev, scan_mask); 1372 pm_runtime_mark_last_busy(dev); 1373 pm_runtime_put_autosuspend(dev); 1374 1375 return ret; 1376 } 1377 1378 static int stm32_adc_of_xlate(struct iio_dev *indio_dev, 1379 const struct of_phandle_args *iiospec) 1380 { 1381 int i; 1382 1383 for (i = 0; i < indio_dev->num_channels; i++) 1384 if (indio_dev->channels[i].channel == iiospec->args[0]) 1385 return i; 1386 1387 return -EINVAL; 1388 } 1389 1390 /** 1391 * stm32_adc_debugfs_reg_access - read or write register value 1392 * @indio_dev: IIO device structure 1393 * @reg: register offset 1394 * @writeval: value to write 1395 * @readval: value to read 1396 * 1397 * To read a value from an ADC register: 1398 * echo [ADC reg offset] > direct_reg_access 1399 * cat direct_reg_access 1400 * 1401 * To write a value in a ADC register: 1402 * echo [ADC_reg_offset] [value] > direct_reg_access 1403 */ 1404 static int stm32_adc_debugfs_reg_access(struct iio_dev *indio_dev, 1405 unsigned reg, unsigned writeval, 1406 unsigned *readval) 1407 { 1408 struct stm32_adc *adc = iio_priv(indio_dev); 1409 struct device *dev = indio_dev->dev.parent; 1410 int ret; 1411 1412 ret = pm_runtime_resume_and_get(dev); 1413 if (ret < 0) 1414 return ret; 1415 1416 if (!readval) 1417 stm32_adc_writel(adc, reg, writeval); 1418 else 1419 *readval = stm32_adc_readl(adc, reg); 1420 1421 pm_runtime_mark_last_busy(dev); 1422 pm_runtime_put_autosuspend(dev); 1423 1424 return 0; 1425 } 1426 1427 static const struct iio_info stm32_adc_iio_info = { 1428 .read_raw = stm32_adc_read_raw, 1429 .validate_trigger = stm32_adc_validate_trigger, 1430 .hwfifo_set_watermark = stm32_adc_set_watermark, 1431 .update_scan_mode = stm32_adc_update_scan_mode, 1432 .debugfs_reg_access = stm32_adc_debugfs_reg_access, 1433 .of_xlate = stm32_adc_of_xlate, 1434 }; 1435 1436 static unsigned int stm32_adc_dma_residue(struct stm32_adc *adc) 1437 { 1438 struct dma_tx_state state; 1439 enum dma_status status; 1440 1441 status = dmaengine_tx_status(adc->dma_chan, 1442 adc->dma_chan->cookie, 1443 &state); 1444 if (status == DMA_IN_PROGRESS) { 1445 /* Residue is size in bytes from end of buffer */ 1446 unsigned int i = adc->rx_buf_sz - state.residue; 1447 unsigned int size; 1448 1449 /* Return available bytes */ 1450 if (i >= adc->bufi) 1451 size = i - adc->bufi; 1452 else 1453 size = adc->rx_buf_sz + i - adc->bufi; 1454 1455 return size; 1456 } 1457 1458 return 0; 1459 } 1460 1461 static void stm32_adc_dma_buffer_done(void *data) 1462 { 1463 struct iio_dev *indio_dev = data; 1464 struct stm32_adc *adc = iio_priv(indio_dev); 1465 int residue = stm32_adc_dma_residue(adc); 1466 1467 /* 1468 * In DMA mode the trigger services of IIO are not used 1469 * (e.g. no call to iio_trigger_poll). 1470 * Calling irq handler associated to the hardware trigger is not 1471 * relevant as the conversions have already been done. Data 1472 * transfers are performed directly in DMA callback instead. 1473 * This implementation avoids to call trigger irq handler that 1474 * may sleep, in an atomic context (DMA irq handler context). 1475 */ 1476 dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi); 1477 1478 while (residue >= indio_dev->scan_bytes) { 1479 u16 *buffer = (u16 *)&adc->rx_buf[adc->bufi]; 1480 1481 iio_push_to_buffers(indio_dev, buffer); 1482 1483 residue -= indio_dev->scan_bytes; 1484 adc->bufi += indio_dev->scan_bytes; 1485 if (adc->bufi >= adc->rx_buf_sz) 1486 adc->bufi = 0; 1487 } 1488 } 1489 1490 static int stm32_adc_dma_start(struct iio_dev *indio_dev) 1491 { 1492 struct stm32_adc *adc = iio_priv(indio_dev); 1493 struct dma_async_tx_descriptor *desc; 1494 dma_cookie_t cookie; 1495 int ret; 1496 1497 if (!adc->dma_chan) 1498 return 0; 1499 1500 dev_dbg(&indio_dev->dev, "%s size=%d watermark=%d\n", __func__, 1501 adc->rx_buf_sz, adc->rx_buf_sz / 2); 1502 1503 /* Prepare a DMA cyclic transaction */ 1504 desc = dmaengine_prep_dma_cyclic(adc->dma_chan, 1505 adc->rx_dma_buf, 1506 adc->rx_buf_sz, adc->rx_buf_sz / 2, 1507 DMA_DEV_TO_MEM, 1508 DMA_PREP_INTERRUPT); 1509 if (!desc) 1510 return -EBUSY; 1511 1512 desc->callback = stm32_adc_dma_buffer_done; 1513 desc->callback_param = indio_dev; 1514 1515 cookie = dmaengine_submit(desc); 1516 ret = dma_submit_error(cookie); 1517 if (ret) { 1518 dmaengine_terminate_sync(adc->dma_chan); 1519 return ret; 1520 } 1521 1522 /* Issue pending DMA requests */ 1523 dma_async_issue_pending(adc->dma_chan); 1524 1525 return 0; 1526 } 1527 1528 static int stm32_adc_buffer_postenable(struct iio_dev *indio_dev) 1529 { 1530 struct stm32_adc *adc = iio_priv(indio_dev); 1531 struct device *dev = indio_dev->dev.parent; 1532 int ret; 1533 1534 ret = pm_runtime_resume_and_get(dev); 1535 if (ret < 0) 1536 return ret; 1537 1538 ret = stm32_adc_set_trig(indio_dev, indio_dev->trig); 1539 if (ret) { 1540 dev_err(&indio_dev->dev, "Can't set trigger\n"); 1541 goto err_pm_put; 1542 } 1543 1544 ret = stm32_adc_dma_start(indio_dev); 1545 if (ret) { 1546 dev_err(&indio_dev->dev, "Can't start dma\n"); 1547 goto err_clr_trig; 1548 } 1549 1550 /* Reset adc buffer index */ 1551 adc->bufi = 0; 1552 1553 stm32_adc_ovr_irq_enable(adc); 1554 1555 if (!adc->dma_chan) 1556 stm32_adc_conv_irq_enable(adc); 1557 1558 adc->cfg->start_conv(indio_dev, !!adc->dma_chan); 1559 1560 return 0; 1561 1562 err_clr_trig: 1563 stm32_adc_set_trig(indio_dev, NULL); 1564 err_pm_put: 1565 pm_runtime_mark_last_busy(dev); 1566 pm_runtime_put_autosuspend(dev); 1567 1568 return ret; 1569 } 1570 1571 static int stm32_adc_buffer_predisable(struct iio_dev *indio_dev) 1572 { 1573 struct stm32_adc *adc = iio_priv(indio_dev); 1574 struct device *dev = indio_dev->dev.parent; 1575 1576 adc->cfg->stop_conv(indio_dev); 1577 if (!adc->dma_chan) 1578 stm32_adc_conv_irq_disable(adc); 1579 1580 stm32_adc_ovr_irq_disable(adc); 1581 1582 if (adc->dma_chan) 1583 dmaengine_terminate_sync(adc->dma_chan); 1584 1585 if (stm32_adc_set_trig(indio_dev, NULL)) 1586 dev_err(&indio_dev->dev, "Can't clear trigger\n"); 1587 1588 pm_runtime_mark_last_busy(dev); 1589 pm_runtime_put_autosuspend(dev); 1590 1591 return 0; 1592 } 1593 1594 static const struct iio_buffer_setup_ops stm32_adc_buffer_setup_ops = { 1595 .postenable = &stm32_adc_buffer_postenable, 1596 .predisable = &stm32_adc_buffer_predisable, 1597 }; 1598 1599 static irqreturn_t stm32_adc_trigger_handler(int irq, void *p) 1600 { 1601 struct iio_poll_func *pf = p; 1602 struct iio_dev *indio_dev = pf->indio_dev; 1603 struct stm32_adc *adc = iio_priv(indio_dev); 1604 1605 dev_dbg(&indio_dev->dev, "%s bufi=%d\n", __func__, adc->bufi); 1606 1607 /* reset buffer index */ 1608 adc->bufi = 0; 1609 iio_push_to_buffers_with_timestamp(indio_dev, adc->buffer, 1610 pf->timestamp); 1611 iio_trigger_notify_done(indio_dev->trig); 1612 1613 /* re-enable eoc irq */ 1614 stm32_adc_conv_irq_enable(adc); 1615 1616 return IRQ_HANDLED; 1617 } 1618 1619 static const struct iio_chan_spec_ext_info stm32_adc_ext_info[] = { 1620 IIO_ENUM("trigger_polarity", IIO_SHARED_BY_ALL, &stm32_adc_trig_pol), 1621 { 1622 .name = "trigger_polarity_available", 1623 .shared = IIO_SHARED_BY_ALL, 1624 .read = iio_enum_available_read, 1625 .private = (uintptr_t)&stm32_adc_trig_pol, 1626 }, 1627 {}, 1628 }; 1629 1630 static int stm32_adc_of_get_resolution(struct iio_dev *indio_dev) 1631 { 1632 struct device_node *node = indio_dev->dev.of_node; 1633 struct stm32_adc *adc = iio_priv(indio_dev); 1634 unsigned int i; 1635 u32 res; 1636 1637 if (of_property_read_u32(node, "assigned-resolution-bits", &res)) 1638 res = adc->cfg->adc_info->resolutions[0]; 1639 1640 for (i = 0; i < adc->cfg->adc_info->num_res; i++) 1641 if (res == adc->cfg->adc_info->resolutions[i]) 1642 break; 1643 if (i >= adc->cfg->adc_info->num_res) { 1644 dev_err(&indio_dev->dev, "Bad resolution: %u bits\n", res); 1645 return -EINVAL; 1646 } 1647 1648 dev_dbg(&indio_dev->dev, "Using %u bits resolution\n", res); 1649 adc->res = i; 1650 1651 return 0; 1652 } 1653 1654 static void stm32_adc_smpr_init(struct stm32_adc *adc, int channel, u32 smp_ns) 1655 { 1656 const struct stm32_adc_regs *smpr = &adc->cfg->regs->smp_bits[channel]; 1657 u32 period_ns, shift = smpr->shift, mask = smpr->mask; 1658 unsigned int smp, r = smpr->reg; 1659 1660 /* Determine sampling time (ADC clock cycles) */ 1661 period_ns = NSEC_PER_SEC / adc->common->rate; 1662 for (smp = 0; smp <= STM32_ADC_MAX_SMP; smp++) 1663 if ((period_ns * adc->cfg->smp_cycles[smp]) >= smp_ns) 1664 break; 1665 if (smp > STM32_ADC_MAX_SMP) 1666 smp = STM32_ADC_MAX_SMP; 1667 1668 /* pre-build sampling time registers (e.g. smpr1, smpr2) */ 1669 adc->smpr_val[r] = (adc->smpr_val[r] & ~mask) | (smp << shift); 1670 } 1671 1672 static void stm32_adc_chan_init_one(struct iio_dev *indio_dev, 1673 struct iio_chan_spec *chan, u32 vinp, 1674 u32 vinn, int scan_index, bool differential) 1675 { 1676 struct stm32_adc *adc = iio_priv(indio_dev); 1677 char *name = adc->chan_name[vinp]; 1678 1679 chan->type = IIO_VOLTAGE; 1680 chan->channel = vinp; 1681 if (differential) { 1682 chan->differential = 1; 1683 chan->channel2 = vinn; 1684 snprintf(name, STM32_ADC_CH_SZ, "in%d-in%d", vinp, vinn); 1685 } else { 1686 snprintf(name, STM32_ADC_CH_SZ, "in%d", vinp); 1687 } 1688 chan->datasheet_name = name; 1689 chan->scan_index = scan_index; 1690 chan->indexed = 1; 1691 chan->info_mask_separate = BIT(IIO_CHAN_INFO_RAW); 1692 chan->info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | 1693 BIT(IIO_CHAN_INFO_OFFSET); 1694 chan->scan_type.sign = 'u'; 1695 chan->scan_type.realbits = adc->cfg->adc_info->resolutions[adc->res]; 1696 chan->scan_type.storagebits = 16; 1697 chan->ext_info = stm32_adc_ext_info; 1698 1699 /* pre-build selected channels mask */ 1700 adc->pcsel |= BIT(chan->channel); 1701 if (differential) { 1702 /* pre-build diff channels mask */ 1703 adc->difsel |= BIT(chan->channel); 1704 /* Also add negative input to pre-selected channels */ 1705 adc->pcsel |= BIT(chan->channel2); 1706 } 1707 } 1708 1709 static int stm32_adc_chan_of_init(struct iio_dev *indio_dev, bool timestamping) 1710 { 1711 struct device_node *node = indio_dev->dev.of_node; 1712 struct stm32_adc *adc = iio_priv(indio_dev); 1713 const struct stm32_adc_info *adc_info = adc->cfg->adc_info; 1714 struct stm32_adc_diff_channel diff[STM32_ADC_CH_MAX]; 1715 struct property *prop; 1716 const __be32 *cur; 1717 struct iio_chan_spec *channels; 1718 int scan_index = 0, num_channels = 0, num_diff = 0, ret, i; 1719 u32 val, smp = 0; 1720 1721 ret = of_property_count_u32_elems(node, "st,adc-channels"); 1722 if (ret > adc_info->max_channels) { 1723 dev_err(&indio_dev->dev, "Bad st,adc-channels?\n"); 1724 return -EINVAL; 1725 } else if (ret > 0) { 1726 num_channels += ret; 1727 } 1728 1729 ret = of_property_count_elems_of_size(node, "st,adc-diff-channels", 1730 sizeof(*diff)); 1731 if (ret > adc_info->max_channels) { 1732 dev_err(&indio_dev->dev, "Bad st,adc-diff-channels?\n"); 1733 return -EINVAL; 1734 } else if (ret > 0) { 1735 int size = ret * sizeof(*diff) / sizeof(u32); 1736 1737 num_diff = ret; 1738 num_channels += ret; 1739 ret = of_property_read_u32_array(node, "st,adc-diff-channels", 1740 (u32 *)diff, size); 1741 if (ret) 1742 return ret; 1743 } 1744 1745 if (!num_channels) { 1746 dev_err(&indio_dev->dev, "No channels configured\n"); 1747 return -ENODATA; 1748 } 1749 1750 /* Optional sample time is provided either for each, or all channels */ 1751 ret = of_property_count_u32_elems(node, "st,min-sample-time-nsecs"); 1752 if (ret > 1 && ret != num_channels) { 1753 dev_err(&indio_dev->dev, "Invalid st,min-sample-time-nsecs\n"); 1754 return -EINVAL; 1755 } 1756 1757 if (timestamping) 1758 num_channels++; 1759 1760 channels = devm_kcalloc(&indio_dev->dev, num_channels, 1761 sizeof(struct iio_chan_spec), GFP_KERNEL); 1762 if (!channels) 1763 return -ENOMEM; 1764 1765 of_property_for_each_u32(node, "st,adc-channels", prop, cur, val) { 1766 if (val >= adc_info->max_channels) { 1767 dev_err(&indio_dev->dev, "Invalid channel %d\n", val); 1768 return -EINVAL; 1769 } 1770 1771 /* Channel can't be configured both as single-ended & diff */ 1772 for (i = 0; i < num_diff; i++) { 1773 if (val == diff[i].vinp) { 1774 dev_err(&indio_dev->dev, 1775 "channel %d miss-configured\n", val); 1776 return -EINVAL; 1777 } 1778 } 1779 stm32_adc_chan_init_one(indio_dev, &channels[scan_index], val, 1780 0, scan_index, false); 1781 scan_index++; 1782 } 1783 1784 for (i = 0; i < num_diff; i++) { 1785 if (diff[i].vinp >= adc_info->max_channels || 1786 diff[i].vinn >= adc_info->max_channels) { 1787 dev_err(&indio_dev->dev, "Invalid channel in%d-in%d\n", 1788 diff[i].vinp, diff[i].vinn); 1789 return -EINVAL; 1790 } 1791 stm32_adc_chan_init_one(indio_dev, &channels[scan_index], 1792 diff[i].vinp, diff[i].vinn, scan_index, 1793 true); 1794 scan_index++; 1795 } 1796 1797 for (i = 0; i < scan_index; i++) { 1798 /* 1799 * Using of_property_read_u32_index(), smp value will only be 1800 * modified if valid u32 value can be decoded. This allows to 1801 * get either no value, 1 shared value for all indexes, or one 1802 * value per channel. 1803 */ 1804 of_property_read_u32_index(node, "st,min-sample-time-nsecs", 1805 i, &smp); 1806 /* Prepare sampling time settings */ 1807 stm32_adc_smpr_init(adc, channels[i].channel, smp); 1808 } 1809 1810 if (timestamping) { 1811 struct iio_chan_spec *timestamp = &channels[scan_index]; 1812 1813 timestamp->type = IIO_TIMESTAMP; 1814 timestamp->channel = -1; 1815 timestamp->scan_index = scan_index; 1816 timestamp->scan_type.sign = 's'; 1817 timestamp->scan_type.realbits = 64; 1818 timestamp->scan_type.storagebits = 64; 1819 1820 scan_index++; 1821 } 1822 1823 indio_dev->num_channels = scan_index; 1824 indio_dev->channels = channels; 1825 1826 return 0; 1827 } 1828 1829 static int stm32_adc_dma_request(struct device *dev, struct iio_dev *indio_dev) 1830 { 1831 struct stm32_adc *adc = iio_priv(indio_dev); 1832 struct dma_slave_config config; 1833 int ret; 1834 1835 adc->dma_chan = dma_request_chan(dev, "rx"); 1836 if (IS_ERR(adc->dma_chan)) { 1837 ret = PTR_ERR(adc->dma_chan); 1838 if (ret != -ENODEV) 1839 return dev_err_probe(dev, ret, 1840 "DMA channel request failed with\n"); 1841 1842 /* DMA is optional: fall back to IRQ mode */ 1843 adc->dma_chan = NULL; 1844 return 0; 1845 } 1846 1847 adc->rx_buf = dma_alloc_coherent(adc->dma_chan->device->dev, 1848 STM32_DMA_BUFFER_SIZE, 1849 &adc->rx_dma_buf, GFP_KERNEL); 1850 if (!adc->rx_buf) { 1851 ret = -ENOMEM; 1852 goto err_release; 1853 } 1854 1855 /* Configure DMA channel to read data register */ 1856 memset(&config, 0, sizeof(config)); 1857 config.src_addr = (dma_addr_t)adc->common->phys_base; 1858 config.src_addr += adc->offset + adc->cfg->regs->dr; 1859 config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES; 1860 1861 ret = dmaengine_slave_config(adc->dma_chan, &config); 1862 if (ret) 1863 goto err_free; 1864 1865 return 0; 1866 1867 err_free: 1868 dma_free_coherent(adc->dma_chan->device->dev, STM32_DMA_BUFFER_SIZE, 1869 adc->rx_buf, adc->rx_dma_buf); 1870 err_release: 1871 dma_release_channel(adc->dma_chan); 1872 1873 return ret; 1874 } 1875 1876 static int stm32_adc_probe(struct platform_device *pdev) 1877 { 1878 struct iio_dev *indio_dev; 1879 struct device *dev = &pdev->dev; 1880 irqreturn_t (*handler)(int irq, void *p) = NULL; 1881 struct stm32_adc *adc; 1882 bool timestamping = false; 1883 int ret; 1884 1885 if (!pdev->dev.of_node) 1886 return -ENODEV; 1887 1888 indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*adc)); 1889 if (!indio_dev) 1890 return -ENOMEM; 1891 1892 adc = iio_priv(indio_dev); 1893 adc->common = dev_get_drvdata(pdev->dev.parent); 1894 spin_lock_init(&adc->lock); 1895 init_completion(&adc->completion); 1896 adc->cfg = (const struct stm32_adc_cfg *) 1897 of_match_device(dev->driver->of_match_table, dev)->data; 1898 1899 indio_dev->name = dev_name(&pdev->dev); 1900 indio_dev->dev.of_node = pdev->dev.of_node; 1901 indio_dev->info = &stm32_adc_iio_info; 1902 indio_dev->modes = INDIO_DIRECT_MODE | INDIO_HARDWARE_TRIGGERED; 1903 1904 platform_set_drvdata(pdev, indio_dev); 1905 1906 ret = of_property_read_u32(pdev->dev.of_node, "reg", &adc->offset); 1907 if (ret != 0) { 1908 dev_err(&pdev->dev, "missing reg property\n"); 1909 return -EINVAL; 1910 } 1911 1912 adc->irq = platform_get_irq(pdev, 0); 1913 if (adc->irq < 0) 1914 return adc->irq; 1915 1916 ret = devm_request_threaded_irq(&pdev->dev, adc->irq, stm32_adc_isr, 1917 stm32_adc_threaded_isr, 1918 0, pdev->name, indio_dev); 1919 if (ret) { 1920 dev_err(&pdev->dev, "failed to request IRQ\n"); 1921 return ret; 1922 } 1923 1924 adc->clk = devm_clk_get(&pdev->dev, NULL); 1925 if (IS_ERR(adc->clk)) { 1926 ret = PTR_ERR(adc->clk); 1927 if (ret == -ENOENT && !adc->cfg->clk_required) { 1928 adc->clk = NULL; 1929 } else { 1930 dev_err(&pdev->dev, "Can't get clock\n"); 1931 return ret; 1932 } 1933 } 1934 1935 ret = stm32_adc_of_get_resolution(indio_dev); 1936 if (ret < 0) 1937 return ret; 1938 1939 ret = stm32_adc_dma_request(dev, indio_dev); 1940 if (ret < 0) 1941 return ret; 1942 1943 if (!adc->dma_chan) { 1944 /* For PIO mode only, iio_pollfunc_store_time stores a timestamp 1945 * in the primary trigger IRQ handler and stm32_adc_trigger_handler 1946 * runs in the IRQ thread to push out buffer along with timestamp. 1947 */ 1948 handler = &stm32_adc_trigger_handler; 1949 timestamping = true; 1950 } 1951 1952 ret = stm32_adc_chan_of_init(indio_dev, timestamping); 1953 if (ret < 0) 1954 goto err_dma_disable; 1955 1956 ret = iio_triggered_buffer_setup(indio_dev, 1957 &iio_pollfunc_store_time, handler, 1958 &stm32_adc_buffer_setup_ops); 1959 if (ret) { 1960 dev_err(&pdev->dev, "buffer setup failed\n"); 1961 goto err_dma_disable; 1962 } 1963 1964 /* Get stm32-adc-core PM online */ 1965 pm_runtime_get_noresume(dev); 1966 pm_runtime_set_active(dev); 1967 pm_runtime_set_autosuspend_delay(dev, STM32_ADC_HW_STOP_DELAY_MS); 1968 pm_runtime_use_autosuspend(dev); 1969 pm_runtime_enable(dev); 1970 1971 ret = stm32_adc_hw_start(dev); 1972 if (ret) 1973 goto err_buffer_cleanup; 1974 1975 ret = iio_device_register(indio_dev); 1976 if (ret) { 1977 dev_err(&pdev->dev, "iio dev register failed\n"); 1978 goto err_hw_stop; 1979 } 1980 1981 pm_runtime_mark_last_busy(dev); 1982 pm_runtime_put_autosuspend(dev); 1983 1984 return 0; 1985 1986 err_hw_stop: 1987 stm32_adc_hw_stop(dev); 1988 1989 err_buffer_cleanup: 1990 pm_runtime_disable(dev); 1991 pm_runtime_set_suspended(dev); 1992 pm_runtime_put_noidle(dev); 1993 iio_triggered_buffer_cleanup(indio_dev); 1994 1995 err_dma_disable: 1996 if (adc->dma_chan) { 1997 dma_free_coherent(adc->dma_chan->device->dev, 1998 STM32_DMA_BUFFER_SIZE, 1999 adc->rx_buf, adc->rx_dma_buf); 2000 dma_release_channel(adc->dma_chan); 2001 } 2002 2003 return ret; 2004 } 2005 2006 static int stm32_adc_remove(struct platform_device *pdev) 2007 { 2008 struct iio_dev *indio_dev = platform_get_drvdata(pdev); 2009 struct stm32_adc *adc = iio_priv(indio_dev); 2010 2011 pm_runtime_get_sync(&pdev->dev); 2012 iio_device_unregister(indio_dev); 2013 stm32_adc_hw_stop(&pdev->dev); 2014 pm_runtime_disable(&pdev->dev); 2015 pm_runtime_set_suspended(&pdev->dev); 2016 pm_runtime_put_noidle(&pdev->dev); 2017 iio_triggered_buffer_cleanup(indio_dev); 2018 if (adc->dma_chan) { 2019 dma_free_coherent(adc->dma_chan->device->dev, 2020 STM32_DMA_BUFFER_SIZE, 2021 adc->rx_buf, adc->rx_dma_buf); 2022 dma_release_channel(adc->dma_chan); 2023 } 2024 2025 return 0; 2026 } 2027 2028 #if defined(CONFIG_PM_SLEEP) 2029 static int stm32_adc_suspend(struct device *dev) 2030 { 2031 struct iio_dev *indio_dev = dev_get_drvdata(dev); 2032 2033 if (iio_buffer_enabled(indio_dev)) 2034 stm32_adc_buffer_predisable(indio_dev); 2035 2036 return pm_runtime_force_suspend(dev); 2037 } 2038 2039 static int stm32_adc_resume(struct device *dev) 2040 { 2041 struct iio_dev *indio_dev = dev_get_drvdata(dev); 2042 int ret; 2043 2044 ret = pm_runtime_force_resume(dev); 2045 if (ret < 0) 2046 return ret; 2047 2048 if (!iio_buffer_enabled(indio_dev)) 2049 return 0; 2050 2051 ret = stm32_adc_update_scan_mode(indio_dev, 2052 indio_dev->active_scan_mask); 2053 if (ret < 0) 2054 return ret; 2055 2056 return stm32_adc_buffer_postenable(indio_dev); 2057 } 2058 #endif 2059 2060 #if defined(CONFIG_PM) 2061 static int stm32_adc_runtime_suspend(struct device *dev) 2062 { 2063 return stm32_adc_hw_stop(dev); 2064 } 2065 2066 static int stm32_adc_runtime_resume(struct device *dev) 2067 { 2068 return stm32_adc_hw_start(dev); 2069 } 2070 #endif 2071 2072 static const struct dev_pm_ops stm32_adc_pm_ops = { 2073 SET_SYSTEM_SLEEP_PM_OPS(stm32_adc_suspend, stm32_adc_resume) 2074 SET_RUNTIME_PM_OPS(stm32_adc_runtime_suspend, stm32_adc_runtime_resume, 2075 NULL) 2076 }; 2077 2078 static const struct stm32_adc_cfg stm32f4_adc_cfg = { 2079 .regs = &stm32f4_adc_regspec, 2080 .adc_info = &stm32f4_adc_info, 2081 .trigs = stm32f4_adc_trigs, 2082 .clk_required = true, 2083 .start_conv = stm32f4_adc_start_conv, 2084 .stop_conv = stm32f4_adc_stop_conv, 2085 .smp_cycles = stm32f4_adc_smp_cycles, 2086 .irq_clear = stm32f4_adc_irq_clear, 2087 }; 2088 2089 static const struct stm32_adc_cfg stm32h7_adc_cfg = { 2090 .regs = &stm32h7_adc_regspec, 2091 .adc_info = &stm32h7_adc_info, 2092 .trigs = stm32h7_adc_trigs, 2093 .start_conv = stm32h7_adc_start_conv, 2094 .stop_conv = stm32h7_adc_stop_conv, 2095 .prepare = stm32h7_adc_prepare, 2096 .unprepare = stm32h7_adc_unprepare, 2097 .smp_cycles = stm32h7_adc_smp_cycles, 2098 .irq_clear = stm32h7_adc_irq_clear, 2099 }; 2100 2101 static const struct stm32_adc_cfg stm32mp1_adc_cfg = { 2102 .regs = &stm32h7_adc_regspec, 2103 .adc_info = &stm32h7_adc_info, 2104 .trigs = stm32h7_adc_trigs, 2105 .has_vregready = true, 2106 .start_conv = stm32h7_adc_start_conv, 2107 .stop_conv = stm32h7_adc_stop_conv, 2108 .prepare = stm32h7_adc_prepare, 2109 .unprepare = stm32h7_adc_unprepare, 2110 .smp_cycles = stm32h7_adc_smp_cycles, 2111 .irq_clear = stm32h7_adc_irq_clear, 2112 }; 2113 2114 static const struct of_device_id stm32_adc_of_match[] = { 2115 { .compatible = "st,stm32f4-adc", .data = (void *)&stm32f4_adc_cfg }, 2116 { .compatible = "st,stm32h7-adc", .data = (void *)&stm32h7_adc_cfg }, 2117 { .compatible = "st,stm32mp1-adc", .data = (void *)&stm32mp1_adc_cfg }, 2118 {}, 2119 }; 2120 MODULE_DEVICE_TABLE(of, stm32_adc_of_match); 2121 2122 static struct platform_driver stm32_adc_driver = { 2123 .probe = stm32_adc_probe, 2124 .remove = stm32_adc_remove, 2125 .driver = { 2126 .name = "stm32-adc", 2127 .of_match_table = stm32_adc_of_match, 2128 .pm = &stm32_adc_pm_ops, 2129 }, 2130 }; 2131 module_platform_driver(stm32_adc_driver); 2132 2133 MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>"); 2134 MODULE_DESCRIPTION("STMicroelectronics STM32 ADC IIO driver"); 2135 MODULE_LICENSE("GPL v2"); 2136 MODULE_ALIAS("platform:stm32-adc"); 2137