1 // SPDX-License-Identifier: GPL-2.0-only 2 /** 3 * Copyright (C) 2020 Microchip 4 * 5 * Author: Kamel Bouhara <kamel.bouhara@bootlin.com> 6 */ 7 #include <linux/clk.h> 8 #include <linux/counter.h> 9 #include <linux/mfd/syscon.h> 10 #include <linux/module.h> 11 #include <linux/mutex.h> 12 #include <linux/of.h> 13 #include <linux/of_device.h> 14 #include <linux/platform_device.h> 15 #include <linux/regmap.h> 16 #include <soc/at91/atmel_tcb.h> 17 18 #define ATMEL_TC_CMR_MASK (ATMEL_TC_LDRA_RISING | ATMEL_TC_LDRB_FALLING | \ 19 ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_LDBDIS | \ 20 ATMEL_TC_LDBSTOP) 21 22 #define ATMEL_TC_QDEN BIT(8) 23 #define ATMEL_TC_POSEN BIT(9) 24 25 struct mchp_tc_data { 26 const struct atmel_tcb_config *tc_cfg; 27 struct counter_device counter; 28 struct regmap *regmap; 29 int qdec_mode; 30 int num_channels; 31 int channel[2]; 32 bool trig_inverted; 33 }; 34 35 enum mchp_tc_count_function { 36 MCHP_TC_FUNCTION_INCREASE, 37 MCHP_TC_FUNCTION_QUADRATURE, 38 }; 39 40 static enum counter_count_function mchp_tc_count_functions[] = { 41 [MCHP_TC_FUNCTION_INCREASE] = COUNTER_COUNT_FUNCTION_INCREASE, 42 [MCHP_TC_FUNCTION_QUADRATURE] = COUNTER_COUNT_FUNCTION_QUADRATURE_X4, 43 }; 44 45 enum mchp_tc_synapse_action { 46 MCHP_TC_SYNAPSE_ACTION_NONE = 0, 47 MCHP_TC_SYNAPSE_ACTION_RISING_EDGE, 48 MCHP_TC_SYNAPSE_ACTION_FALLING_EDGE, 49 MCHP_TC_SYNAPSE_ACTION_BOTH_EDGE 50 }; 51 52 static enum counter_synapse_action mchp_tc_synapse_actions[] = { 53 [MCHP_TC_SYNAPSE_ACTION_NONE] = COUNTER_SYNAPSE_ACTION_NONE, 54 [MCHP_TC_SYNAPSE_ACTION_RISING_EDGE] = COUNTER_SYNAPSE_ACTION_RISING_EDGE, 55 [MCHP_TC_SYNAPSE_ACTION_FALLING_EDGE] = COUNTER_SYNAPSE_ACTION_FALLING_EDGE, 56 [MCHP_TC_SYNAPSE_ACTION_BOTH_EDGE] = COUNTER_SYNAPSE_ACTION_BOTH_EDGES, 57 }; 58 59 static struct counter_signal mchp_tc_count_signals[] = { 60 { 61 .id = 0, 62 .name = "Channel A", 63 }, 64 { 65 .id = 1, 66 .name = "Channel B", 67 } 68 }; 69 70 static struct counter_synapse mchp_tc_count_synapses[] = { 71 { 72 .actions_list = mchp_tc_synapse_actions, 73 .num_actions = ARRAY_SIZE(mchp_tc_synapse_actions), 74 .signal = &mchp_tc_count_signals[0] 75 }, 76 { 77 .actions_list = mchp_tc_synapse_actions, 78 .num_actions = ARRAY_SIZE(mchp_tc_synapse_actions), 79 .signal = &mchp_tc_count_signals[1] 80 } 81 }; 82 83 static int mchp_tc_count_function_get(struct counter_device *counter, 84 struct counter_count *count, 85 size_t *function) 86 { 87 struct mchp_tc_data *const priv = counter->priv; 88 89 if (priv->qdec_mode) 90 *function = MCHP_TC_FUNCTION_QUADRATURE; 91 else 92 *function = MCHP_TC_FUNCTION_INCREASE; 93 94 return 0; 95 } 96 97 static int mchp_tc_count_function_set(struct counter_device *counter, 98 struct counter_count *count, 99 size_t function) 100 { 101 struct mchp_tc_data *const priv = counter->priv; 102 u32 bmr, cmr; 103 104 regmap_read(priv->regmap, ATMEL_TC_BMR, &bmr); 105 regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr); 106 107 /* Set capture mode */ 108 cmr &= ~ATMEL_TC_WAVE; 109 110 switch (function) { 111 case MCHP_TC_FUNCTION_INCREASE: 112 priv->qdec_mode = 0; 113 /* Set highest rate based on whether soc has gclk or not */ 114 bmr &= ~(ATMEL_TC_QDEN | ATMEL_TC_POSEN); 115 if (priv->tc_cfg->has_gclk) 116 cmr |= ATMEL_TC_TIMER_CLOCK2; 117 else 118 cmr |= ATMEL_TC_TIMER_CLOCK1; 119 /* Setup the period capture mode */ 120 cmr |= ATMEL_TC_CMR_MASK; 121 cmr &= ~(ATMEL_TC_ABETRG | ATMEL_TC_XC0); 122 break; 123 case MCHP_TC_FUNCTION_QUADRATURE: 124 if (!priv->tc_cfg->has_qdec) 125 return -EINVAL; 126 /* In QDEC mode settings both channels 0 and 1 are required */ 127 if (priv->num_channels < 2 || priv->channel[0] != 0 || 128 priv->channel[1] != 1) { 129 pr_err("Invalid channels number or id for quadrature mode\n"); 130 return -EINVAL; 131 } 132 priv->qdec_mode = 1; 133 bmr |= ATMEL_TC_QDEN | ATMEL_TC_POSEN; 134 cmr |= ATMEL_TC_ETRGEDG_RISING | ATMEL_TC_ABETRG | ATMEL_TC_XC0; 135 break; 136 } 137 138 regmap_write(priv->regmap, ATMEL_TC_BMR, bmr); 139 regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), cmr); 140 141 /* Enable clock and trigger counter */ 142 regmap_write(priv->regmap, ATMEL_TC_REG(priv->channel[0], CCR), 143 ATMEL_TC_CLKEN | ATMEL_TC_SWTRG); 144 145 if (priv->qdec_mode) { 146 regmap_write(priv->regmap, 147 ATMEL_TC_REG(priv->channel[1], CMR), cmr); 148 regmap_write(priv->regmap, 149 ATMEL_TC_REG(priv->channel[1], CCR), 150 ATMEL_TC_CLKEN | ATMEL_TC_SWTRG); 151 } 152 153 return 0; 154 } 155 156 static int mchp_tc_count_signal_read(struct counter_device *counter, 157 struct counter_signal *signal, 158 enum counter_signal_value *val) 159 { 160 struct mchp_tc_data *const priv = counter->priv; 161 bool sigstatus; 162 u32 sr; 163 164 regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], SR), &sr); 165 166 if (priv->trig_inverted) 167 sigstatus = (sr & ATMEL_TC_MTIOB); 168 else 169 sigstatus = (sr & ATMEL_TC_MTIOA); 170 171 *val = sigstatus ? COUNTER_SIGNAL_HIGH : COUNTER_SIGNAL_LOW; 172 173 return 0; 174 } 175 176 static int mchp_tc_count_action_get(struct counter_device *counter, 177 struct counter_count *count, 178 struct counter_synapse *synapse, 179 size_t *action) 180 { 181 struct mchp_tc_data *const priv = counter->priv; 182 u32 cmr; 183 184 regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CMR), &cmr); 185 186 *action = MCHP_TC_SYNAPSE_ACTION_NONE; 187 188 if (cmr & ATMEL_TC_ETRGEDG_NONE) 189 *action = MCHP_TC_SYNAPSE_ACTION_NONE; 190 else if (cmr & ATMEL_TC_ETRGEDG_RISING) 191 *action = MCHP_TC_SYNAPSE_ACTION_RISING_EDGE; 192 else if (cmr & ATMEL_TC_ETRGEDG_FALLING) 193 *action = MCHP_TC_SYNAPSE_ACTION_FALLING_EDGE; 194 else if (cmr & ATMEL_TC_ETRGEDG_BOTH) 195 *action = MCHP_TC_SYNAPSE_ACTION_BOTH_EDGE; 196 197 return 0; 198 } 199 200 static int mchp_tc_count_action_set(struct counter_device *counter, 201 struct counter_count *count, 202 struct counter_synapse *synapse, 203 size_t action) 204 { 205 struct mchp_tc_data *const priv = counter->priv; 206 u32 edge = ATMEL_TC_ETRGEDG_NONE; 207 208 /* QDEC mode is rising edge only */ 209 if (priv->qdec_mode) 210 return -EINVAL; 211 212 switch (action) { 213 case MCHP_TC_SYNAPSE_ACTION_NONE: 214 edge = ATMEL_TC_ETRGEDG_NONE; 215 break; 216 case MCHP_TC_SYNAPSE_ACTION_RISING_EDGE: 217 edge = ATMEL_TC_ETRGEDG_RISING; 218 break; 219 case MCHP_TC_SYNAPSE_ACTION_FALLING_EDGE: 220 edge = ATMEL_TC_ETRGEDG_FALLING; 221 break; 222 case MCHP_TC_SYNAPSE_ACTION_BOTH_EDGE: 223 edge = ATMEL_TC_ETRGEDG_BOTH; 224 break; 225 } 226 227 return regmap_write_bits(priv->regmap, 228 ATMEL_TC_REG(priv->channel[0], CMR), 229 ATMEL_TC_ETRGEDG, edge); 230 } 231 232 static int mchp_tc_count_read(struct counter_device *counter, 233 struct counter_count *count, 234 unsigned long *val) 235 { 236 struct mchp_tc_data *const priv = counter->priv; 237 u32 cnt; 238 239 regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CV), &cnt); 240 *val = cnt; 241 242 return 0; 243 } 244 245 static struct counter_count mchp_tc_counts[] = { 246 { 247 .id = 0, 248 .name = "Timer Counter", 249 .functions_list = mchp_tc_count_functions, 250 .num_functions = ARRAY_SIZE(mchp_tc_count_functions), 251 .synapses = mchp_tc_count_synapses, 252 .num_synapses = ARRAY_SIZE(mchp_tc_count_synapses), 253 }, 254 }; 255 256 static struct counter_ops mchp_tc_ops = { 257 .signal_read = mchp_tc_count_signal_read, 258 .count_read = mchp_tc_count_read, 259 .function_get = mchp_tc_count_function_get, 260 .function_set = mchp_tc_count_function_set, 261 .action_get = mchp_tc_count_action_get, 262 .action_set = mchp_tc_count_action_set 263 }; 264 265 static const struct atmel_tcb_config tcb_rm9200_config = { 266 .counter_width = 16, 267 }; 268 269 static const struct atmel_tcb_config tcb_sam9x5_config = { 270 .counter_width = 32, 271 }; 272 273 static const struct atmel_tcb_config tcb_sama5d2_config = { 274 .counter_width = 32, 275 .has_gclk = true, 276 .has_qdec = true, 277 }; 278 279 static const struct atmel_tcb_config tcb_sama5d3_config = { 280 .counter_width = 32, 281 .has_qdec = true, 282 }; 283 284 static const struct of_device_id atmel_tc_of_match[] = { 285 { .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, }, 286 { .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, }, 287 { .compatible = "atmel,sama5d2-tcb", .data = &tcb_sama5d2_config, }, 288 { .compatible = "atmel,sama5d3-tcb", .data = &tcb_sama5d3_config, }, 289 { /* sentinel */ } 290 }; 291 292 static void mchp_tc_clk_remove(void *ptr) 293 { 294 clk_disable_unprepare((struct clk *)ptr); 295 } 296 297 static int mchp_tc_probe(struct platform_device *pdev) 298 { 299 struct device_node *np = pdev->dev.of_node; 300 const struct atmel_tcb_config *tcb_config; 301 const struct of_device_id *match; 302 struct mchp_tc_data *priv; 303 char clk_name[7]; 304 struct regmap *regmap; 305 struct clk *clk[3]; 306 int channel; 307 int ret, i; 308 309 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); 310 if (!priv) 311 return -ENOMEM; 312 313 platform_set_drvdata(pdev, priv); 314 315 match = of_match_node(atmel_tc_of_match, np->parent); 316 tcb_config = match->data; 317 if (!tcb_config) { 318 dev_err(&pdev->dev, "No matching parent node found\n"); 319 return -ENODEV; 320 } 321 322 regmap = syscon_node_to_regmap(np->parent); 323 if (IS_ERR(priv->regmap)) 324 return PTR_ERR(priv->regmap); 325 326 /* max. channels number is 2 when in QDEC mode */ 327 priv->num_channels = of_property_count_u32_elems(np, "reg"); 328 if (priv->num_channels < 0) { 329 dev_err(&pdev->dev, "Invalid or missing channel\n"); 330 return -EINVAL; 331 } 332 333 /* Register channels and initialize clocks */ 334 for (i = 0; i < priv->num_channels; i++) { 335 ret = of_property_read_u32_index(np, "reg", i, &channel); 336 if (ret < 0 || channel > 2) 337 return -ENODEV; 338 339 priv->channel[i] = channel; 340 341 snprintf(clk_name, sizeof(clk_name), "t%d_clk", channel); 342 343 clk[i] = of_clk_get_by_name(np->parent, clk_name); 344 if (IS_ERR(clk[i])) { 345 /* Fallback to t0_clk */ 346 clk[i] = of_clk_get_by_name(np->parent, "t0_clk"); 347 if (IS_ERR(clk[i])) 348 return PTR_ERR(clk[i]); 349 } 350 351 ret = clk_prepare_enable(clk[i]); 352 if (ret) 353 return ret; 354 355 ret = devm_add_action_or_reset(&pdev->dev, 356 mchp_tc_clk_remove, 357 clk[i]); 358 if (ret) 359 return ret; 360 361 dev_dbg(&pdev->dev, 362 "Initialized capture mode on channel %d\n", 363 channel); 364 } 365 366 priv->tc_cfg = tcb_config; 367 priv->regmap = regmap; 368 priv->counter.name = dev_name(&pdev->dev); 369 priv->counter.parent = &pdev->dev; 370 priv->counter.ops = &mchp_tc_ops; 371 priv->counter.num_counts = ARRAY_SIZE(mchp_tc_counts); 372 priv->counter.counts = mchp_tc_counts; 373 priv->counter.num_signals = ARRAY_SIZE(mchp_tc_count_signals); 374 priv->counter.signals = mchp_tc_count_signals; 375 priv->counter.priv = priv; 376 377 return devm_counter_register(&pdev->dev, &priv->counter); 378 } 379 380 static const struct of_device_id mchp_tc_dt_ids[] = { 381 { .compatible = "microchip,tcb-capture", }, 382 { /* sentinel */ }, 383 }; 384 MODULE_DEVICE_TABLE(of, mchp_tc_dt_ids); 385 386 static struct platform_driver mchp_tc_driver = { 387 .probe = mchp_tc_probe, 388 .driver = { 389 .name = "microchip-tcb-capture", 390 .of_match_table = mchp_tc_dt_ids, 391 }, 392 }; 393 module_platform_driver(mchp_tc_driver); 394 395 MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>"); 396 MODULE_DESCRIPTION("Microchip TCB Capture driver"); 397 MODULE_LICENSE("GPL v2"); 398