drivers/staging/greybus/pwm.c

   1 /*
   2  * PWM Greybus driver.
   3  *
   4  * Copyright 2014 Google Inc.
   5  * Copyright 2014 Linaro Ltd.
   6  *
   7  * Released under the GPLv2 only.
   8  */
   9
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/slab.h>
  13 #include <linux/pwm.h>
  14
  15 #include "greybus.h"
  16 #include "gbphy.h"
  17
  18 struct gb_pwm_chip {
  19         struct gb_connection    *connection;
  20         u8                      pwm_max;        /* max pwm number */
  21
  22         struct pwm_chip         chip;
  23         struct pwm_chip         *pwm;
  24 };
  25 #define pwm_chip_to_gb_pwm_chip(chip) \
  26         container_of(chip, struct gb_pwm_chip, chip)
  27
  28
  29 static int gb_pwm_count_operation(struct gb_pwm_chip *pwmc)
  30 {
  31         struct gb_pwm_count_response response;
  32         int ret;
  33
  34         ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_PWM_COUNT,
  35                                 NULL, 0, &response, sizeof(response));
  36         if (ret)
  37                 return ret;
  38         pwmc->pwm_max = response.count;
  39         return 0;
  40 }
  41
  42 static int gb_pwm_activate_operation(struct gb_pwm_chip *pwmc,
  43                                      u8 which)
  44 {
  45         struct gb_pwm_activate_request request;
  46         struct gbphy_device *gbphy_dev;
  47         int ret;
  48
  49         if (which > pwmc->pwm_max)
  50                 return -EINVAL;
  51
  52         request.which = which;
  53
  54         gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
  55         ret = gbphy_runtime_get_sync(gbphy_dev);
  56         if (ret)
  57                 return ret;
  58
  59         ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ACTIVATE,
  60                                 &request, sizeof(request), NULL, 0);
  61
  62         gbphy_runtime_put_autosuspend(gbphy_dev);
  63
  64         return ret;
  65 }
  66
  67 static int gb_pwm_deactivate_operation(struct gb_pwm_chip *pwmc,
  68                                        u8 which)
  69 {
  70         struct gb_pwm_deactivate_request request;
  71         struct gbphy_device *gbphy_dev;
  72         int ret;
  73
  74         if (which > pwmc->pwm_max)
  75                 return -EINVAL;
  76
  77         request.which = which;
  78
  79         gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
  80         ret = gbphy_runtime_get_sync(gbphy_dev);
  81         if (ret)
  82                 return ret;
  83
  84         ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DEACTIVATE,
  85                                 &request, sizeof(request), NULL, 0);
  86
  87         gbphy_runtime_put_autosuspend(gbphy_dev);
  88
  89         return ret;
  90 }
  91
  92 static int gb_pwm_config_operation(struct gb_pwm_chip *pwmc,
  93                                    u8 which, u32 duty, u32 period)
  94 {
  95         struct gb_pwm_config_request request;
  96         struct gbphy_device *gbphy_dev;
  97         int ret;
  98
  99         if (which > pwmc->pwm_max)
 100                 return -EINVAL;
 101
 102         request.which = which;
 103         request.duty = cpu_to_le32(duty);
 104         request.period = cpu_to_le32(period);
 105
 106         gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
 107         ret = gbphy_runtime_get_sync(gbphy_dev);
 108         if (ret)
 109                 return ret;
 110
 111         ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_CONFIG,
 112                                 &request, sizeof(request), NULL, 0);
 113
 114         gbphy_runtime_put_autosuspend(gbphy_dev);
 115
 116         return ret;
 117 }
 118
 119 static int gb_pwm_set_polarity_operation(struct gb_pwm_chip *pwmc,
 120                                          u8 which, u8 polarity)
 121 {
 122         struct gb_pwm_polarity_request request;
 123         struct gbphy_device *gbphy_dev;
 124         int ret;
 125
 126         if (which > pwmc->pwm_max)
 127                 return -EINVAL;
 128
 129         request.which = which;
 130         request.polarity = polarity;
 131
 132         gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
 133         ret = gbphy_runtime_get_sync(gbphy_dev);
 134         if (ret)
 135                 return ret;
 136
 137         ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_POLARITY,
 138                                 &request, sizeof(request), NULL, 0);
 139
 140         gbphy_runtime_put_autosuspend(gbphy_dev);
 141
 142         return ret;
 143 }
 144
 145 static int gb_pwm_enable_operation(struct gb_pwm_chip *pwmc,
 146                                    u8 which)
 147 {
 148         struct gb_pwm_enable_request request;
 149         struct gbphy_device *gbphy_dev;
 150         int ret;
 151
 152         if (which > pwmc->pwm_max)
 153                 return -EINVAL;
 154
 155         request.which = which;
 156
 157         gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
 158         ret = gbphy_runtime_get_sync(gbphy_dev);
 159         if (ret)
 160                 return ret;
 161
 162         ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_ENABLE,
 163                                 &request, sizeof(request), NULL, 0);
 164         if (ret)
 165                 gbphy_runtime_put_autosuspend(gbphy_dev);
 166
 167         return ret;
 168 }
 169
 170 static int gb_pwm_disable_operation(struct gb_pwm_chip *pwmc,
 171                                     u8 which)
 172 {
 173         struct gb_pwm_disable_request request;
 174         struct gbphy_device *gbphy_dev;
 175         int ret;
 176
 177         if (which > pwmc->pwm_max)
 178                 return -EINVAL;
 179
 180         request.which = which;
 181
 182         ret = gb_operation_sync(pwmc->connection, GB_PWM_TYPE_DISABLE,
 183                                 &request, sizeof(request), NULL, 0);
 184
 185         gbphy_dev = to_gbphy_dev(pwmc->chip.dev);
 186         gbphy_runtime_put_autosuspend(gbphy_dev);
 187
 188         return ret;
 189 }
 190
 191 static int gb_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm)
 192 {
 193         struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 194
 195         return gb_pwm_activate_operation(pwmc, pwm->hwpwm);
 196 };
 197
 198 static void gb_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm)
 199 {
 200         struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 201
 202         if (pwm_is_enabled(pwm))
 203                 dev_warn(chip->dev, "freeing PWM device without disabling\n");
 204
 205         gb_pwm_deactivate_operation(pwmc, pwm->hwpwm);
 206 }
 207
 208 static int gb_pwm_config(struct pwm_chip *chip, struct pwm_device *pwm,
 209                          int duty_ns, int period_ns)
 210 {
 211         struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 212
 213         return gb_pwm_config_operation(pwmc, pwm->hwpwm, duty_ns, period_ns);
 214 };
 215
 216 static int gb_pwm_set_polarity(struct pwm_chip *chip, struct pwm_device *pwm,
 217                                enum pwm_polarity polarity)
 218 {
 219         struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 220
 221         return gb_pwm_set_polarity_operation(pwmc, pwm->hwpwm, polarity);
 222 };
 223
 224 static int gb_pwm_enable(struct pwm_chip *chip, struct pwm_device *pwm)
 225 {
 226         struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 227
 228         return gb_pwm_enable_operation(pwmc, pwm->hwpwm);
 229 };
 230
 231 static void gb_pwm_disable(struct pwm_chip *chip, struct pwm_device *pwm)
 232 {
 233         struct gb_pwm_chip *pwmc = pwm_chip_to_gb_pwm_chip(chip);
 234
 235         gb_pwm_disable_operation(pwmc, pwm->hwpwm);
 236 };
 237
 238 static const struct pwm_ops gb_pwm_ops = {
 239         .request = gb_pwm_request,
 240         .free = gb_pwm_free,
 241         .config = gb_pwm_config,
 242         .set_polarity = gb_pwm_set_polarity,
 243         .enable = gb_pwm_enable,
 244         .disable = gb_pwm_disable,
 245         .owner = THIS_MODULE,
 246 };
 247
 248 static int gb_pwm_probe(struct gbphy_device *gbphy_dev,
 249                         const struct gbphy_device_id *id)
 250 {
 251         struct gb_connection *connection;
 252         struct gb_pwm_chip *pwmc;
 253         struct pwm_chip *pwm;
 254         int ret;
 255
 256         pwmc = kzalloc(sizeof(*pwmc), GFP_KERNEL);
 257         if (!pwmc)
 258                 return -ENOMEM;
 259
 260         connection = gb_connection_create(gbphy_dev->bundle,
 261                                           le16_to_cpu(gbphy_dev->cport_desc->id),
 262                                           NULL);
 263         if (IS_ERR(connection)) {
 264                 ret = PTR_ERR(connection);
 265                 goto exit_pwmc_free;
 266         }
 267
 268         pwmc->connection = connection;
 269         gb_connection_set_data(connection, pwmc);
 270         gb_gbphy_set_data(gbphy_dev, pwmc);
 271
 272         ret = gb_connection_enable(connection);
 273         if (ret)
 274                 goto exit_connection_destroy;
 275
 276         /* Query number of pwms present */
 277         ret = gb_pwm_count_operation(pwmc);
 278         if (ret)
 279                 goto exit_connection_disable;
 280
 281         pwm = &pwmc->chip;
 282
 283         pwm->dev = &gbphy_dev->dev;
 284         pwm->ops = &gb_pwm_ops;
 285         pwm->base = -1;                 /* Allocate base dynamically */
 286         pwm->npwm = pwmc->pwm_max + 1;
 287
 288         ret = pwmchip_add(pwm);
 289         if (ret) {
 290                 dev_err(&gbphy_dev->dev,
 291                         "failed to register PWM: %d\n", ret);
 292                 goto exit_connection_disable;
 293         }
 294
 295         gbphy_runtime_put_autosuspend(gbphy_dev);
 296         return 0;
 297
 298 exit_connection_disable:
 299         gb_connection_disable(connection);
 300 exit_connection_destroy:
 301         gb_connection_destroy(connection);
 302 exit_pwmc_free:
 303         kfree(pwmc);
 304         return ret;
 305 }
 306
 307 static void gb_pwm_remove(struct gbphy_device *gbphy_dev)
 308 {
 309         struct gb_pwm_chip *pwmc = gb_gbphy_get_data(gbphy_dev);
 310         struct gb_connection *connection = pwmc->connection;
 311         int ret;
 312
 313         ret = gbphy_runtime_get_sync(gbphy_dev);
 314         if (ret)
 315                 gbphy_runtime_get_noresume(gbphy_dev);
 316
 317         pwmchip_remove(&pwmc->chip);
 318         gb_connection_disable(connection);
 319         gb_connection_destroy(connection);
 320         kfree(pwmc);
 321 }
 322
 323 static const struct gbphy_device_id gb_pwm_id_table[] = {
 324         { GBPHY_PROTOCOL(GREYBUS_PROTOCOL_PWM) },
 325         { },
 326 };
 327 MODULE_DEVICE_TABLE(gbphy, gb_pwm_id_table);
 328
 329 static struct gbphy_driver pwm_driver = {
 330         .name           = "pwm",
 331         .probe          = gb_pwm_probe,
 332         .remove         = gb_pwm_remove,
 333         .id_table       = gb_pwm_id_table,
 334 };
 335
 336 module_gbphy_driver(pwm_driver);
 337 MODULE_LICENSE("GPL v2");