Fabrice Gasnier | 597f55e | 2019-04-02 15:30:44 +0900 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * STM32 Low-Power Timer Encoder and Counter driver |
| 4 | * |
| 5 | * Copyright (C) STMicroelectronics 2017 |
| 6 | * |
| 7 | * Author: Fabrice Gasnier <fabrice.gasnier@st.com> |
| 8 | * |
| 9 | * Inspired by 104-quad-8 and stm32-timer-trigger drivers. |
| 10 | * |
| 11 | */ |
| 12 | |
| 13 | #include <linux/bitfield.h> |
| 14 | #include <linux/counter.h> |
| 15 | #include <linux/iio/iio.h> |
| 16 | #include <linux/mfd/stm32-lptimer.h> |
| 17 | #include <linux/module.h> |
| 18 | #include <linux/pinctrl/consumer.h> |
| 19 | #include <linux/platform_device.h> |
| 20 | |
| 21 | struct stm32_lptim_cnt { |
| 22 | struct counter_device counter; |
| 23 | struct device *dev; |
| 24 | struct regmap *regmap; |
| 25 | struct clk *clk; |
| 26 | u32 ceiling; |
| 27 | u32 polarity; |
| 28 | u32 quadrature_mode; |
| 29 | bool enabled; |
| 30 | }; |
| 31 | |
| 32 | static int stm32_lptim_is_enabled(struct stm32_lptim_cnt *priv) |
| 33 | { |
| 34 | u32 val; |
| 35 | int ret; |
| 36 | |
| 37 | ret = regmap_read(priv->regmap, STM32_LPTIM_CR, &val); |
| 38 | if (ret) |
| 39 | return ret; |
| 40 | |
| 41 | return FIELD_GET(STM32_LPTIM_ENABLE, val); |
| 42 | } |
| 43 | |
| 44 | static int stm32_lptim_set_enable_state(struct stm32_lptim_cnt *priv, |
| 45 | int enable) |
| 46 | { |
| 47 | int ret; |
| 48 | u32 val; |
| 49 | |
| 50 | val = FIELD_PREP(STM32_LPTIM_ENABLE, enable); |
| 51 | ret = regmap_write(priv->regmap, STM32_LPTIM_CR, val); |
| 52 | if (ret) |
| 53 | return ret; |
| 54 | |
| 55 | if (!enable) { |
| 56 | clk_disable(priv->clk); |
| 57 | priv->enabled = false; |
| 58 | return 0; |
| 59 | } |
| 60 | |
| 61 | /* LP timer must be enabled before writing CMP & ARR */ |
| 62 | ret = regmap_write(priv->regmap, STM32_LPTIM_ARR, priv->ceiling); |
| 63 | if (ret) |
| 64 | return ret; |
| 65 | |
| 66 | ret = regmap_write(priv->regmap, STM32_LPTIM_CMP, 0); |
| 67 | if (ret) |
| 68 | return ret; |
| 69 | |
| 70 | /* ensure CMP & ARR registers are properly written */ |
| 71 | ret = regmap_read_poll_timeout(priv->regmap, STM32_LPTIM_ISR, val, |
| 72 | (val & STM32_LPTIM_CMPOK_ARROK), |
| 73 | 100, 1000); |
| 74 | if (ret) |
| 75 | return ret; |
| 76 | |
| 77 | ret = regmap_write(priv->regmap, STM32_LPTIM_ICR, |
| 78 | STM32_LPTIM_CMPOKCF_ARROKCF); |
| 79 | if (ret) |
| 80 | return ret; |
| 81 | |
| 82 | ret = clk_enable(priv->clk); |
| 83 | if (ret) { |
| 84 | regmap_write(priv->regmap, STM32_LPTIM_CR, 0); |
| 85 | return ret; |
| 86 | } |
| 87 | priv->enabled = true; |
| 88 | |
| 89 | /* Start LP timer in continuous mode */ |
| 90 | return regmap_update_bits(priv->regmap, STM32_LPTIM_CR, |
| 91 | STM32_LPTIM_CNTSTRT, STM32_LPTIM_CNTSTRT); |
| 92 | } |
| 93 | |
| 94 | static int stm32_lptim_setup(struct stm32_lptim_cnt *priv, int enable) |
| 95 | { |
| 96 | u32 mask = STM32_LPTIM_ENC | STM32_LPTIM_COUNTMODE | |
| 97 | STM32_LPTIM_CKPOL | STM32_LPTIM_PRESC; |
| 98 | u32 val; |
| 99 | |
| 100 | /* Setup LP timer encoder/counter and polarity, without prescaler */ |
| 101 | if (priv->quadrature_mode) |
| 102 | val = enable ? STM32_LPTIM_ENC : 0; |
| 103 | else |
| 104 | val = enable ? STM32_LPTIM_COUNTMODE : 0; |
| 105 | val |= FIELD_PREP(STM32_LPTIM_CKPOL, enable ? priv->polarity : 0); |
| 106 | |
| 107 | return regmap_update_bits(priv->regmap, STM32_LPTIM_CFGR, mask, val); |
| 108 | } |
| 109 | |
| 110 | static int stm32_lptim_write_raw(struct iio_dev *indio_dev, |
| 111 | struct iio_chan_spec const *chan, |
| 112 | int val, int val2, long mask) |
| 113 | { |
| 114 | struct stm32_lptim_cnt *priv = iio_priv(indio_dev); |
| 115 | int ret; |
| 116 | |
| 117 | switch (mask) { |
| 118 | case IIO_CHAN_INFO_ENABLE: |
| 119 | if (val < 0 || val > 1) |
| 120 | return -EINVAL; |
| 121 | |
| 122 | /* Check nobody uses the timer, or already disabled/enabled */ |
| 123 | ret = stm32_lptim_is_enabled(priv); |
| 124 | if ((ret < 0) || (!ret && !val)) |
| 125 | return ret; |
| 126 | if (val && ret) |
| 127 | return -EBUSY; |
| 128 | |
| 129 | ret = stm32_lptim_setup(priv, val); |
| 130 | if (ret) |
| 131 | return ret; |
| 132 | return stm32_lptim_set_enable_state(priv, val); |
| 133 | |
| 134 | default: |
| 135 | return -EINVAL; |
| 136 | } |
| 137 | } |
| 138 | |
| 139 | static int stm32_lptim_read_raw(struct iio_dev *indio_dev, |
| 140 | struct iio_chan_spec const *chan, |
| 141 | int *val, int *val2, long mask) |
| 142 | { |
| 143 | struct stm32_lptim_cnt *priv = iio_priv(indio_dev); |
| 144 | u32 dat; |
| 145 | int ret; |
| 146 | |
| 147 | switch (mask) { |
| 148 | case IIO_CHAN_INFO_RAW: |
| 149 | ret = regmap_read(priv->regmap, STM32_LPTIM_CNT, &dat); |
| 150 | if (ret) |
| 151 | return ret; |
| 152 | *val = dat; |
| 153 | return IIO_VAL_INT; |
| 154 | |
| 155 | case IIO_CHAN_INFO_ENABLE: |
| 156 | ret = stm32_lptim_is_enabled(priv); |
| 157 | if (ret < 0) |
| 158 | return ret; |
| 159 | *val = ret; |
| 160 | return IIO_VAL_INT; |
| 161 | |
| 162 | case IIO_CHAN_INFO_SCALE: |
| 163 | /* Non-quadrature mode: scale = 1 */ |
| 164 | *val = 1; |
| 165 | *val2 = 0; |
| 166 | if (priv->quadrature_mode) { |
| 167 | /* |
| 168 | * Quadrature encoder mode: |
| 169 | * - both edges, quarter cycle, scale is 0.25 |
| 170 | * - either rising/falling edge scale is 0.5 |
| 171 | */ |
| 172 | if (priv->polarity > 1) |
| 173 | *val2 = 2; |
| 174 | else |
| 175 | *val2 = 1; |
| 176 | } |
| 177 | return IIO_VAL_FRACTIONAL_LOG2; |
| 178 | |
| 179 | default: |
| 180 | return -EINVAL; |
| 181 | } |
| 182 | } |
| 183 | |
| 184 | static const struct iio_info stm32_lptim_cnt_iio_info = { |
| 185 | .read_raw = stm32_lptim_read_raw, |
| 186 | .write_raw = stm32_lptim_write_raw, |
| 187 | }; |
| 188 | |
| 189 | static const char *const stm32_lptim_quadrature_modes[] = { |
| 190 | "non-quadrature", |
| 191 | "quadrature", |
| 192 | }; |
| 193 | |
| 194 | static int stm32_lptim_get_quadrature_mode(struct iio_dev *indio_dev, |
| 195 | const struct iio_chan_spec *chan) |
| 196 | { |
| 197 | struct stm32_lptim_cnt *priv = iio_priv(indio_dev); |
| 198 | |
| 199 | return priv->quadrature_mode; |
| 200 | } |
| 201 | |
| 202 | static int stm32_lptim_set_quadrature_mode(struct iio_dev *indio_dev, |
| 203 | const struct iio_chan_spec *chan, |
| 204 | unsigned int type) |
| 205 | { |
| 206 | struct stm32_lptim_cnt *priv = iio_priv(indio_dev); |
| 207 | |
| 208 | if (stm32_lptim_is_enabled(priv)) |
| 209 | return -EBUSY; |
| 210 | |
| 211 | priv->quadrature_mode = type; |
| 212 | |
| 213 | return 0; |
| 214 | } |
| 215 | |
| 216 | static const struct iio_enum stm32_lptim_quadrature_mode_en = { |
| 217 | .items = stm32_lptim_quadrature_modes, |
| 218 | .num_items = ARRAY_SIZE(stm32_lptim_quadrature_modes), |
| 219 | .get = stm32_lptim_get_quadrature_mode, |
| 220 | .set = stm32_lptim_set_quadrature_mode, |
| 221 | }; |
| 222 | |
| 223 | static const char * const stm32_lptim_cnt_polarity[] = { |
| 224 | "rising-edge", "falling-edge", "both-edges", |
| 225 | }; |
| 226 | |
| 227 | static int stm32_lptim_cnt_get_polarity(struct iio_dev *indio_dev, |
| 228 | const struct iio_chan_spec *chan) |
| 229 | { |
| 230 | struct stm32_lptim_cnt *priv = iio_priv(indio_dev); |
| 231 | |
| 232 | return priv->polarity; |
| 233 | } |
| 234 | |
| 235 | static int stm32_lptim_cnt_set_polarity(struct iio_dev *indio_dev, |
| 236 | const struct iio_chan_spec *chan, |
| 237 | unsigned int type) |
| 238 | { |
| 239 | struct stm32_lptim_cnt *priv = iio_priv(indio_dev); |
| 240 | |
| 241 | if (stm32_lptim_is_enabled(priv)) |
| 242 | return -EBUSY; |
| 243 | |
| 244 | priv->polarity = type; |
| 245 | |
| 246 | return 0; |
| 247 | } |
| 248 | |
| 249 | static const struct iio_enum stm32_lptim_cnt_polarity_en = { |
| 250 | .items = stm32_lptim_cnt_polarity, |
| 251 | .num_items = ARRAY_SIZE(stm32_lptim_cnt_polarity), |
| 252 | .get = stm32_lptim_cnt_get_polarity, |
| 253 | .set = stm32_lptim_cnt_set_polarity, |
| 254 | }; |
| 255 | |
| 256 | static ssize_t stm32_lptim_cnt_get_ceiling(struct stm32_lptim_cnt *priv, |
| 257 | char *buf) |
| 258 | { |
| 259 | return snprintf(buf, PAGE_SIZE, "%u\n", priv->ceiling); |
| 260 | } |
| 261 | |
| 262 | static ssize_t stm32_lptim_cnt_set_ceiling(struct stm32_lptim_cnt *priv, |
| 263 | const char *buf, size_t len) |
| 264 | { |
| 265 | int ret; |
| 266 | |
| 267 | if (stm32_lptim_is_enabled(priv)) |
| 268 | return -EBUSY; |
| 269 | |
| 270 | ret = kstrtouint(buf, 0, &priv->ceiling); |
| 271 | if (ret) |
| 272 | return ret; |
| 273 | |
| 274 | if (priv->ceiling > STM32_LPTIM_MAX_ARR) |
| 275 | return -EINVAL; |
| 276 | |
| 277 | return len; |
| 278 | } |
| 279 | |
| 280 | static ssize_t stm32_lptim_cnt_get_preset_iio(struct iio_dev *indio_dev, |
| 281 | uintptr_t private, |
| 282 | const struct iio_chan_spec *chan, |
| 283 | char *buf) |
| 284 | { |
| 285 | struct stm32_lptim_cnt *priv = iio_priv(indio_dev); |
| 286 | |
| 287 | return stm32_lptim_cnt_get_ceiling(priv, buf); |
| 288 | } |
| 289 | |
| 290 | static ssize_t stm32_lptim_cnt_set_preset_iio(struct iio_dev *indio_dev, |
| 291 | uintptr_t private, |
| 292 | const struct iio_chan_spec *chan, |
| 293 | const char *buf, size_t len) |
| 294 | { |
| 295 | struct stm32_lptim_cnt *priv = iio_priv(indio_dev); |
| 296 | |
| 297 | return stm32_lptim_cnt_set_ceiling(priv, buf, len); |
| 298 | } |
| 299 | |
| 300 | /* LP timer with encoder */ |
| 301 | static const struct iio_chan_spec_ext_info stm32_lptim_enc_ext_info[] = { |
| 302 | { |
| 303 | .name = "preset", |
| 304 | .shared = IIO_SEPARATE, |
| 305 | .read = stm32_lptim_cnt_get_preset_iio, |
| 306 | .write = stm32_lptim_cnt_set_preset_iio, |
| 307 | }, |
| 308 | IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en), |
| 309 | IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en), |
| 310 | IIO_ENUM("quadrature_mode", IIO_SEPARATE, |
| 311 | &stm32_lptim_quadrature_mode_en), |
| 312 | IIO_ENUM_AVAILABLE("quadrature_mode", &stm32_lptim_quadrature_mode_en), |
| 313 | {} |
| 314 | }; |
| 315 | |
| 316 | static const struct iio_chan_spec stm32_lptim_enc_channels = { |
| 317 | .type = IIO_COUNT, |
| 318 | .channel = 0, |
| 319 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
| 320 | BIT(IIO_CHAN_INFO_ENABLE) | |
| 321 | BIT(IIO_CHAN_INFO_SCALE), |
| 322 | .ext_info = stm32_lptim_enc_ext_info, |
| 323 | .indexed = 1, |
| 324 | }; |
| 325 | |
| 326 | /* LP timer without encoder (counter only) */ |
| 327 | static const struct iio_chan_spec_ext_info stm32_lptim_cnt_ext_info[] = { |
| 328 | { |
| 329 | .name = "preset", |
| 330 | .shared = IIO_SEPARATE, |
| 331 | .read = stm32_lptim_cnt_get_preset_iio, |
| 332 | .write = stm32_lptim_cnt_set_preset_iio, |
| 333 | }, |
| 334 | IIO_ENUM("polarity", IIO_SEPARATE, &stm32_lptim_cnt_polarity_en), |
| 335 | IIO_ENUM_AVAILABLE("polarity", &stm32_lptim_cnt_polarity_en), |
| 336 | {} |
| 337 | }; |
| 338 | |
| 339 | static const struct iio_chan_spec stm32_lptim_cnt_channels = { |
| 340 | .type = IIO_COUNT, |
| 341 | .channel = 0, |
| 342 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | |
| 343 | BIT(IIO_CHAN_INFO_ENABLE) | |
| 344 | BIT(IIO_CHAN_INFO_SCALE), |
| 345 | .ext_info = stm32_lptim_cnt_ext_info, |
| 346 | .indexed = 1, |
| 347 | }; |
| 348 | |
| 349 | /** |
Fabrice Gasnier | 81ba7e8 | 2019-09-18 14:22:41 +0200 | [diff] [blame] | 350 | * enum stm32_lptim_cnt_function - enumerates LPTimer counter & encoder modes |
Fabrice Gasnier | 597f55e | 2019-04-02 15:30:44 +0900 | [diff] [blame] | 351 | * @STM32_LPTIM_COUNTER_INCREASE: up count on IN1 rising, falling or both edges |
| 352 | * @STM32_LPTIM_ENCODER_BOTH_EDGE: count on both edges (IN1 & IN2 quadrature) |
| 353 | */ |
| 354 | enum stm32_lptim_cnt_function { |
| 355 | STM32_LPTIM_COUNTER_INCREASE, |
| 356 | STM32_LPTIM_ENCODER_BOTH_EDGE, |
| 357 | }; |
| 358 | |
| 359 | static enum counter_count_function stm32_lptim_cnt_functions[] = { |
| 360 | [STM32_LPTIM_COUNTER_INCREASE] = COUNTER_COUNT_FUNCTION_INCREASE, |
| 361 | [STM32_LPTIM_ENCODER_BOTH_EDGE] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4, |
| 362 | }; |
| 363 | |
| 364 | enum stm32_lptim_synapse_action { |
| 365 | STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE, |
| 366 | STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE, |
| 367 | STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES, |
| 368 | STM32_LPTIM_SYNAPSE_ACTION_NONE, |
| 369 | }; |
| 370 | |
| 371 | static enum counter_synapse_action stm32_lptim_cnt_synapse_actions[] = { |
| 372 | /* Index must match with stm32_lptim_cnt_polarity[] (priv->polarity) */ |
| 373 | [STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE, |
| 374 | [STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE] = COUNTER_SYNAPSE_ACTION_FALLING_EDGE, |
| 375 | [STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES, |
| 376 | [STM32_LPTIM_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE, |
| 377 | }; |
| 378 | |
| 379 | static int stm32_lptim_cnt_read(struct counter_device *counter, |
William Breathitt Gray | d49e6ee | 2019-10-06 16:03:09 -0400 | [diff] [blame] | 380 | struct counter_count *count, unsigned long *val) |
Fabrice Gasnier | 597f55e | 2019-04-02 15:30:44 +0900 | [diff] [blame] | 381 | { |
| 382 | struct stm32_lptim_cnt *const priv = counter->priv; |
| 383 | u32 cnt; |
| 384 | int ret; |
| 385 | |
| 386 | ret = regmap_read(priv->regmap, STM32_LPTIM_CNT, &cnt); |
| 387 | if (ret) |
| 388 | return ret; |
| 389 | |
William Breathitt Gray | d49e6ee | 2019-10-06 16:03:09 -0400 | [diff] [blame] | 390 | *val = cnt; |
Fabrice Gasnier | 597f55e | 2019-04-02 15:30:44 +0900 | [diff] [blame] | 391 | |
| 392 | return 0; |
| 393 | } |
| 394 | |
| 395 | static int stm32_lptim_cnt_function_get(struct counter_device *counter, |
| 396 | struct counter_count *count, |
| 397 | size_t *function) |
| 398 | { |
| 399 | struct stm32_lptim_cnt *const priv = counter->priv; |
| 400 | |
| 401 | if (!priv->quadrature_mode) { |
| 402 | *function = STM32_LPTIM_COUNTER_INCREASE; |
| 403 | return 0; |
| 404 | } |
| 405 | |
| 406 | if (priv->polarity == STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES) { |
| 407 | *function = STM32_LPTIM_ENCODER_BOTH_EDGE; |
| 408 | return 0; |
| 409 | } |
| 410 | |
| 411 | return -EINVAL; |
| 412 | } |
| 413 | |
| 414 | static int stm32_lptim_cnt_function_set(struct counter_device *counter, |
| 415 | struct counter_count *count, |
| 416 | size_t function) |
| 417 | { |
| 418 | struct stm32_lptim_cnt *const priv = counter->priv; |
| 419 | |
| 420 | if (stm32_lptim_is_enabled(priv)) |
| 421 | return -EBUSY; |
| 422 | |
| 423 | switch (function) { |
| 424 | case STM32_LPTIM_COUNTER_INCREASE: |
| 425 | priv->quadrature_mode = 0; |
| 426 | return 0; |
| 427 | case STM32_LPTIM_ENCODER_BOTH_EDGE: |
| 428 | priv->quadrature_mode = 1; |
| 429 | priv->polarity = STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES; |
| 430 | return 0; |
| 431 | } |
| 432 | |
| 433 | return -EINVAL; |
| 434 | } |
| 435 | |
| 436 | static ssize_t stm32_lptim_cnt_enable_read(struct counter_device *counter, |
| 437 | struct counter_count *count, |
| 438 | void *private, char *buf) |
| 439 | { |
| 440 | struct stm32_lptim_cnt *const priv = counter->priv; |
| 441 | int ret; |
| 442 | |
| 443 | ret = stm32_lptim_is_enabled(priv); |
| 444 | if (ret < 0) |
| 445 | return ret; |
| 446 | |
| 447 | return scnprintf(buf, PAGE_SIZE, "%u\n", ret); |
| 448 | } |
| 449 | |
| 450 | static ssize_t stm32_lptim_cnt_enable_write(struct counter_device *counter, |
| 451 | struct counter_count *count, |
| 452 | void *private, |
| 453 | const char *buf, size_t len) |
| 454 | { |
| 455 | struct stm32_lptim_cnt *const priv = counter->priv; |
| 456 | bool enable; |
| 457 | int ret; |
| 458 | |
| 459 | ret = kstrtobool(buf, &enable); |
| 460 | if (ret) |
| 461 | return ret; |
| 462 | |
| 463 | /* Check nobody uses the timer, or already disabled/enabled */ |
| 464 | ret = stm32_lptim_is_enabled(priv); |
| 465 | if ((ret < 0) || (!ret && !enable)) |
| 466 | return ret; |
| 467 | if (enable && ret) |
| 468 | return -EBUSY; |
| 469 | |
| 470 | ret = stm32_lptim_setup(priv, enable); |
| 471 | if (ret) |
| 472 | return ret; |
| 473 | |
| 474 | ret = stm32_lptim_set_enable_state(priv, enable); |
| 475 | if (ret) |
| 476 | return ret; |
| 477 | |
| 478 | return len; |
| 479 | } |
| 480 | |
| 481 | static ssize_t stm32_lptim_cnt_ceiling_read(struct counter_device *counter, |
| 482 | struct counter_count *count, |
| 483 | void *private, char *buf) |
| 484 | { |
| 485 | struct stm32_lptim_cnt *const priv = counter->priv; |
| 486 | |
| 487 | return stm32_lptim_cnt_get_ceiling(priv, buf); |
| 488 | } |
| 489 | |
| 490 | static ssize_t stm32_lptim_cnt_ceiling_write(struct counter_device *counter, |
| 491 | struct counter_count *count, |
| 492 | void *private, |
| 493 | const char *buf, size_t len) |
| 494 | { |
| 495 | struct stm32_lptim_cnt *const priv = counter->priv; |
| 496 | |
| 497 | return stm32_lptim_cnt_set_ceiling(priv, buf, len); |
| 498 | } |
| 499 | |
| 500 | static const struct counter_count_ext stm32_lptim_cnt_ext[] = { |
| 501 | { |
| 502 | .name = "enable", |
| 503 | .read = stm32_lptim_cnt_enable_read, |
| 504 | .write = stm32_lptim_cnt_enable_write |
| 505 | }, |
| 506 | { |
| 507 | .name = "ceiling", |
| 508 | .read = stm32_lptim_cnt_ceiling_read, |
| 509 | .write = stm32_lptim_cnt_ceiling_write |
| 510 | }, |
| 511 | }; |
| 512 | |
| 513 | static int stm32_lptim_cnt_action_get(struct counter_device *counter, |
| 514 | struct counter_count *count, |
| 515 | struct counter_synapse *synapse, |
| 516 | size_t *action) |
| 517 | { |
| 518 | struct stm32_lptim_cnt *const priv = counter->priv; |
| 519 | size_t function; |
| 520 | int err; |
| 521 | |
| 522 | err = stm32_lptim_cnt_function_get(counter, count, &function); |
| 523 | if (err) |
| 524 | return err; |
| 525 | |
| 526 | switch (function) { |
| 527 | case STM32_LPTIM_COUNTER_INCREASE: |
| 528 | /* LP Timer acts as up-counter on input 1 */ |
| 529 | if (synapse->signal->id == count->synapses[0].signal->id) |
| 530 | *action = priv->polarity; |
| 531 | else |
| 532 | *action = STM32_LPTIM_SYNAPSE_ACTION_NONE; |
| 533 | return 0; |
| 534 | case STM32_LPTIM_ENCODER_BOTH_EDGE: |
| 535 | *action = priv->polarity; |
| 536 | return 0; |
| 537 | } |
| 538 | |
| 539 | return -EINVAL; |
| 540 | } |
| 541 | |
| 542 | static int stm32_lptim_cnt_action_set(struct counter_device *counter, |
| 543 | struct counter_count *count, |
| 544 | struct counter_synapse *synapse, |
| 545 | size_t action) |
| 546 | { |
| 547 | struct stm32_lptim_cnt *const priv = counter->priv; |
| 548 | size_t function; |
| 549 | int err; |
| 550 | |
| 551 | if (stm32_lptim_is_enabled(priv)) |
| 552 | return -EBUSY; |
| 553 | |
| 554 | err = stm32_lptim_cnt_function_get(counter, count, &function); |
| 555 | if (err) |
| 556 | return err; |
| 557 | |
| 558 | /* only set polarity when in counter mode (on input 1) */ |
| 559 | if (function == STM32_LPTIM_COUNTER_INCREASE |
| 560 | && synapse->signal->id == count->synapses[0].signal->id) { |
| 561 | switch (action) { |
| 562 | case STM32_LPTIM_SYNAPSE_ACTION_RISING_EDGE: |
| 563 | case STM32_LPTIM_SYNAPSE_ACTION_FALLING_EDGE: |
| 564 | case STM32_LPTIM_SYNAPSE_ACTION_BOTH_EDGES: |
| 565 | priv->polarity = action; |
| 566 | return 0; |
| 567 | } |
| 568 | } |
| 569 | |
| 570 | return -EINVAL; |
| 571 | } |
| 572 | |
| 573 | static const struct counter_ops stm32_lptim_cnt_ops = { |
| 574 | .count_read = stm32_lptim_cnt_read, |
| 575 | .function_get = stm32_lptim_cnt_function_get, |
| 576 | .function_set = stm32_lptim_cnt_function_set, |
| 577 | .action_get = stm32_lptim_cnt_action_get, |
| 578 | .action_set = stm32_lptim_cnt_action_set, |
| 579 | }; |
| 580 | |
| 581 | static struct counter_signal stm32_lptim_cnt_signals[] = { |
| 582 | { |
| 583 | .id = 0, |
| 584 | .name = "Channel 1 Quadrature A" |
| 585 | }, |
| 586 | { |
| 587 | .id = 1, |
| 588 | .name = "Channel 1 Quadrature B" |
| 589 | } |
| 590 | }; |
| 591 | |
| 592 | static struct counter_synapse stm32_lptim_cnt_synapses[] = { |
| 593 | { |
| 594 | .actions_list = stm32_lptim_cnt_synapse_actions, |
| 595 | .num_actions = ARRAY_SIZE(stm32_lptim_cnt_synapse_actions), |
| 596 | .signal = &stm32_lptim_cnt_signals[0] |
| 597 | }, |
| 598 | { |
| 599 | .actions_list = stm32_lptim_cnt_synapse_actions, |
| 600 | .num_actions = ARRAY_SIZE(stm32_lptim_cnt_synapse_actions), |
| 601 | .signal = &stm32_lptim_cnt_signals[1] |
| 602 | } |
| 603 | }; |
| 604 | |
| 605 | /* LP timer with encoder */ |
| 606 | static struct counter_count stm32_lptim_enc_counts = { |
| 607 | .id = 0, |
| 608 | .name = "LPTimer Count", |
| 609 | .functions_list = stm32_lptim_cnt_functions, |
| 610 | .num_functions = ARRAY_SIZE(stm32_lptim_cnt_functions), |
| 611 | .synapses = stm32_lptim_cnt_synapses, |
| 612 | .num_synapses = ARRAY_SIZE(stm32_lptim_cnt_synapses), |
| 613 | .ext = stm32_lptim_cnt_ext, |
| 614 | .num_ext = ARRAY_SIZE(stm32_lptim_cnt_ext) |
| 615 | }; |
| 616 | |
| 617 | /* LP timer without encoder (counter only) */ |
| 618 | static struct counter_count stm32_lptim_in1_counts = { |
| 619 | .id = 0, |
| 620 | .name = "LPTimer Count", |
| 621 | .functions_list = stm32_lptim_cnt_functions, |
| 622 | .num_functions = 1, |
| 623 | .synapses = stm32_lptim_cnt_synapses, |
| 624 | .num_synapses = 1, |
| 625 | .ext = stm32_lptim_cnt_ext, |
| 626 | .num_ext = ARRAY_SIZE(stm32_lptim_cnt_ext) |
| 627 | }; |
| 628 | |
| 629 | static int stm32_lptim_cnt_probe(struct platform_device *pdev) |
| 630 | { |
| 631 | struct stm32_lptimer *ddata = dev_get_drvdata(pdev->dev.parent); |
| 632 | struct stm32_lptim_cnt *priv; |
| 633 | struct iio_dev *indio_dev; |
| 634 | int ret; |
| 635 | |
| 636 | if (IS_ERR_OR_NULL(ddata)) |
| 637 | return -EINVAL; |
| 638 | |
| 639 | indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv)); |
| 640 | if (!indio_dev) |
| 641 | return -ENOMEM; |
| 642 | |
| 643 | priv = iio_priv(indio_dev); |
| 644 | priv->dev = &pdev->dev; |
| 645 | priv->regmap = ddata->regmap; |
| 646 | priv->clk = ddata->clk; |
| 647 | priv->ceiling = STM32_LPTIM_MAX_ARR; |
| 648 | |
| 649 | /* Initialize IIO device */ |
| 650 | indio_dev->name = dev_name(&pdev->dev); |
Fabrice Gasnier | 597f55e | 2019-04-02 15:30:44 +0900 | [diff] [blame] | 651 | indio_dev->dev.of_node = pdev->dev.of_node; |
| 652 | indio_dev->info = &stm32_lptim_cnt_iio_info; |
| 653 | if (ddata->has_encoder) |
| 654 | indio_dev->channels = &stm32_lptim_enc_channels; |
| 655 | else |
| 656 | indio_dev->channels = &stm32_lptim_cnt_channels; |
| 657 | indio_dev->num_channels = 1; |
| 658 | |
| 659 | /* Initialize Counter device */ |
| 660 | priv->counter.name = dev_name(&pdev->dev); |
| 661 | priv->counter.parent = &pdev->dev; |
| 662 | priv->counter.ops = &stm32_lptim_cnt_ops; |
| 663 | if (ddata->has_encoder) { |
| 664 | priv->counter.counts = &stm32_lptim_enc_counts; |
| 665 | priv->counter.num_signals = ARRAY_SIZE(stm32_lptim_cnt_signals); |
| 666 | } else { |
| 667 | priv->counter.counts = &stm32_lptim_in1_counts; |
| 668 | priv->counter.num_signals = 1; |
| 669 | } |
| 670 | priv->counter.num_counts = 1; |
| 671 | priv->counter.signals = stm32_lptim_cnt_signals; |
| 672 | priv->counter.priv = priv; |
| 673 | |
| 674 | platform_set_drvdata(pdev, priv); |
| 675 | |
| 676 | ret = devm_iio_device_register(&pdev->dev, indio_dev); |
| 677 | if (ret) |
| 678 | return ret; |
| 679 | |
| 680 | return devm_counter_register(&pdev->dev, &priv->counter); |
| 681 | } |
| 682 | |
| 683 | #ifdef CONFIG_PM_SLEEP |
| 684 | static int stm32_lptim_cnt_suspend(struct device *dev) |
| 685 | { |
| 686 | struct stm32_lptim_cnt *priv = dev_get_drvdata(dev); |
| 687 | int ret; |
| 688 | |
| 689 | /* Only take care of enabled counter: don't disturb other MFD child */ |
| 690 | if (priv->enabled) { |
| 691 | ret = stm32_lptim_setup(priv, 0); |
| 692 | if (ret) |
| 693 | return ret; |
| 694 | |
| 695 | ret = stm32_lptim_set_enable_state(priv, 0); |
| 696 | if (ret) |
| 697 | return ret; |
| 698 | |
| 699 | /* Force enable state for later resume */ |
| 700 | priv->enabled = true; |
| 701 | } |
| 702 | |
| 703 | return pinctrl_pm_select_sleep_state(dev); |
| 704 | } |
| 705 | |
| 706 | static int stm32_lptim_cnt_resume(struct device *dev) |
| 707 | { |
| 708 | struct stm32_lptim_cnt *priv = dev_get_drvdata(dev); |
| 709 | int ret; |
| 710 | |
| 711 | ret = pinctrl_pm_select_default_state(dev); |
| 712 | if (ret) |
| 713 | return ret; |
| 714 | |
| 715 | if (priv->enabled) { |
| 716 | priv->enabled = false; |
| 717 | ret = stm32_lptim_setup(priv, 1); |
| 718 | if (ret) |
| 719 | return ret; |
| 720 | |
| 721 | ret = stm32_lptim_set_enable_state(priv, 1); |
| 722 | if (ret) |
| 723 | return ret; |
| 724 | } |
| 725 | |
| 726 | return 0; |
| 727 | } |
| 728 | #endif |
| 729 | |
| 730 | static SIMPLE_DEV_PM_OPS(stm32_lptim_cnt_pm_ops, stm32_lptim_cnt_suspend, |
| 731 | stm32_lptim_cnt_resume); |
| 732 | |
| 733 | static const struct of_device_id stm32_lptim_cnt_of_match[] = { |
| 734 | { .compatible = "st,stm32-lptimer-counter", }, |
| 735 | {}, |
| 736 | }; |
| 737 | MODULE_DEVICE_TABLE(of, stm32_lptim_cnt_of_match); |
| 738 | |
| 739 | static struct platform_driver stm32_lptim_cnt_driver = { |
| 740 | .probe = stm32_lptim_cnt_probe, |
| 741 | .driver = { |
| 742 | .name = "stm32-lptimer-counter", |
| 743 | .of_match_table = stm32_lptim_cnt_of_match, |
| 744 | .pm = &stm32_lptim_cnt_pm_ops, |
| 745 | }, |
| 746 | }; |
| 747 | module_platform_driver(stm32_lptim_cnt_driver); |
| 748 | |
| 749 | MODULE_AUTHOR("Fabrice Gasnier <fabrice.gasnier@st.com>"); |
| 750 | MODULE_ALIAS("platform:stm32-lptimer-counter"); |
| 751 | MODULE_DESCRIPTION("STMicroelectronics STM32 LPTIM counter driver"); |
| 752 | MODULE_LICENSE("GPL v2"); |