drivers/counter/microchip-tcb-capture.c

   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 const 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 const 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         switch (cmr & ATMEL_TC_ETRGEDG) {
 187         default:
 188                 *action = MCHP_TC_SYNAPSE_ACTION_NONE;
 189                 break;
 190         case ATMEL_TC_ETRGEDG_RISING:
 191                 *action = MCHP_TC_SYNAPSE_ACTION_RISING_EDGE;
 192                 break;
 193         case ATMEL_TC_ETRGEDG_FALLING:
 194                 *action = MCHP_TC_SYNAPSE_ACTION_FALLING_EDGE;
 195                 break;
 196         case ATMEL_TC_ETRGEDG_BOTH:
 197                 *action = MCHP_TC_SYNAPSE_ACTION_BOTH_EDGE;
 198                 break;
 199         }
 200
 201         return 0;
 202 }
 203
 204 static int mchp_tc_count_action_set(struct counter_device *counter,
 205                                     struct counter_count *count,
 206                                     struct counter_synapse *synapse,
 207                                     size_t action)
 208 {
 209         struct mchp_tc_data *const priv = counter->priv;
 210         u32 edge = ATMEL_TC_ETRGEDG_NONE;
 211
 212         /* QDEC mode is rising edge only */
 213         if (priv->qdec_mode)
 214                 return -EINVAL;
 215
 216         switch (action) {
 217         case MCHP_TC_SYNAPSE_ACTION_NONE:
 218                 edge = ATMEL_TC_ETRGEDG_NONE;
 219                 break;
 220         case MCHP_TC_SYNAPSE_ACTION_RISING_EDGE:
 221                 edge = ATMEL_TC_ETRGEDG_RISING;
 222                 break;
 223         case MCHP_TC_SYNAPSE_ACTION_FALLING_EDGE:
 224                 edge = ATMEL_TC_ETRGEDG_FALLING;
 225                 break;
 226         case MCHP_TC_SYNAPSE_ACTION_BOTH_EDGE:
 227                 edge = ATMEL_TC_ETRGEDG_BOTH;
 228                 break;
 229         }
 230
 231         return regmap_write_bits(priv->regmap,
 232                                 ATMEL_TC_REG(priv->channel[0], CMR),
 233                                 ATMEL_TC_ETRGEDG, edge);
 234 }
 235
 236 static int mchp_tc_count_read(struct counter_device *counter,
 237                               struct counter_count *count,
 238                               unsigned long *val)
 239 {
 240         struct mchp_tc_data *const priv = counter->priv;
 241         u32 cnt;
 242
 243         regmap_read(priv->regmap, ATMEL_TC_REG(priv->channel[0], CV), &cnt);
 244         *val = cnt;
 245
 246         return 0;
 247 }
 248
 249 static struct counter_count mchp_tc_counts[] = {
 250         {
 251                 .id = 0,
 252                 .name = "Timer Counter",
 253                 .functions_list = mchp_tc_count_functions,
 254                 .num_functions = ARRAY_SIZE(mchp_tc_count_functions),
 255                 .synapses = mchp_tc_count_synapses,
 256                 .num_synapses = ARRAY_SIZE(mchp_tc_count_synapses),
 257         },
 258 };
 259
 260 static const struct counter_ops mchp_tc_ops = {
 261         .signal_read  = mchp_tc_count_signal_read,
 262         .count_read   = mchp_tc_count_read,
 263         .function_get = mchp_tc_count_function_get,
 264         .function_set = mchp_tc_count_function_set,
 265         .action_get   = mchp_tc_count_action_get,
 266         .action_set   = mchp_tc_count_action_set
 267 };
 268
 269 static const struct atmel_tcb_config tcb_rm9200_config = {
 270                 .counter_width = 16,
 271 };
 272
 273 static const struct atmel_tcb_config tcb_sam9x5_config = {
 274                 .counter_width = 32,
 275 };
 276
 277 static const struct atmel_tcb_config tcb_sama5d2_config = {
 278                 .counter_width = 32,
 279                 .has_gclk = true,
 280                 .has_qdec = true,
 281 };
 282
 283 static const struct atmel_tcb_config tcb_sama5d3_config = {
 284                 .counter_width = 32,
 285                 .has_qdec = true,
 286 };
 287
 288 static const struct of_device_id atmel_tc_of_match[] = {
 289         { .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, },
 290         { .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, },
 291         { .compatible = "atmel,sama5d2-tcb", .data = &tcb_sama5d2_config, },
 292         { .compatible = "atmel,sama5d3-tcb", .data = &tcb_sama5d3_config, },
 293         { /* sentinel */ }
 294 };
 295
 296 static void mchp_tc_clk_remove(void *ptr)
 297 {
 298         clk_disable_unprepare((struct clk *)ptr);
 299 }
 300
 301 static int mchp_tc_probe(struct platform_device *pdev)
 302 {
 303         struct device_node *np = pdev->dev.of_node;
 304         const struct atmel_tcb_config *tcb_config;
 305         const struct of_device_id *match;
 306         struct mchp_tc_data *priv;
 307         char clk_name[7];
 308         struct regmap *regmap;
 309         struct clk *clk[3];
 310         int channel;
 311         int ret, i;
 312
 313         priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
 314         if (!priv)
 315                 return -ENOMEM;
 316
 317         platform_set_drvdata(pdev, priv);
 318
 319         match = of_match_node(atmel_tc_of_match, np->parent);
 320         tcb_config = match->data;
 321         if (!tcb_config) {
 322                 dev_err(&pdev->dev, "No matching parent node found\n");
 323                 return -ENODEV;
 324         }
 325
 326         regmap = syscon_node_to_regmap(np->parent);
 327         if (IS_ERR(regmap))
 328                 return PTR_ERR(regmap);
 329
 330         /* max. channels number is 2 when in QDEC mode */
 331         priv->num_channels = of_property_count_u32_elems(np, "reg");
 332         if (priv->num_channels < 0) {
 333                 dev_err(&pdev->dev, "Invalid or missing channel\n");
 334                 return -EINVAL;
 335         }
 336
 337         /* Register channels and initialize clocks */
 338         for (i = 0; i < priv->num_channels; i++) {
 339                 ret = of_property_read_u32_index(np, "reg", i, &channel);
 340                 if (ret < 0 || channel > 2)
 341                         return -ENODEV;
 342
 343                 priv->channel[i] = channel;
 344
 345                 snprintf(clk_name, sizeof(clk_name), "t%d_clk", channel);
 346
 347                 clk[i] = of_clk_get_by_name(np->parent, clk_name);
 348                 if (IS_ERR(clk[i])) {
 349                         /* Fallback to t0_clk */
 350                         clk[i] = of_clk_get_by_name(np->parent, "t0_clk");
 351                         if (IS_ERR(clk[i]))
 352                                 return PTR_ERR(clk[i]);
 353                 }
 354
 355                 ret = clk_prepare_enable(clk[i]);
 356                 if (ret)
 357                         return ret;
 358
 359                 ret = devm_add_action_or_reset(&pdev->dev,
 360                                                mchp_tc_clk_remove,
 361                                                clk[i]);
 362                 if (ret)
 363                         return ret;
 364
 365                 dev_dbg(&pdev->dev,
 366                         "Initialized capture mode on channel %d\n",
 367                         channel);
 368         }
 369
 370         priv->tc_cfg = tcb_config;
 371         priv->regmap = regmap;
 372         priv->counter.name = dev_name(&pdev->dev);
 373         priv->counter.parent = &pdev->dev;
 374         priv->counter.ops = &mchp_tc_ops;
 375         priv->counter.num_counts = ARRAY_SIZE(mchp_tc_counts);
 376         priv->counter.counts = mchp_tc_counts;
 377         priv->counter.num_signals = ARRAY_SIZE(mchp_tc_count_signals);
 378         priv->counter.signals = mchp_tc_count_signals;
 379         priv->counter.priv = priv;
 380
 381         return devm_counter_register(&pdev->dev, &priv->counter);
 382 }
 383
 384 static const struct of_device_id mchp_tc_dt_ids[] = {
 385         { .compatible = "microchip,tcb-capture", },
 386         { /* sentinel */ },
 387 };
 388 MODULE_DEVICE_TABLE(of, mchp_tc_dt_ids);
 389
 390 static struct platform_driver mchp_tc_driver = {
 391         .probe = mchp_tc_probe,
 392         .driver = {
 393                 .name = "microchip-tcb-capture",
 394                 .of_match_table = mchp_tc_dt_ids,
 395         },
 396 };
 397 module_platform_driver(mchp_tc_driver);
 398
 399 MODULE_AUTHOR("Kamel Bouhara <kamel.bouhara@bootlin.com>");
 400 MODULE_DESCRIPTION("Microchip TCB Capture driver");
 401 MODULE_LICENSE("GPL v2");