drivers/media/platform/cros-ec-cec/cros-ec-cec.c

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * CEC driver for ChromeOS Embedded Controller
   4  *
   5  * Copyright (c) 2018 BayLibre, SAS
   6  * Author: Neil Armstrong <narmstrong@baylibre.com>
   7  */
   8
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/dmi.h>
  13 #include <linux/pci.h>
  14 #include <linux/cec.h>
  15 #include <linux/slab.h>
  16 #include <linux/interrupt.h>
  17 #include <media/cec.h>
  18 #include <media/cec-notifier.h>
  19 #include <linux/mfd/cros_ec.h>
  20 #include <linux/mfd/cros_ec_commands.h>
  21
  22 #define DRV_NAME        "cros-ec-cec"
  23
  24 /**
  25  * struct cros_ec_cec - Driver data for EC CEC
  26  *
  27  * @cros_ec: Pointer to EC device
  28  * @notifier: Notifier info for responding to EC events
  29  * @adap: CEC adapter
  30  * @notify: CEC notifier pointer
  31  * @rx_msg: storage for a received message
  32  */
  33 struct cros_ec_cec {
  34         struct cros_ec_device *cros_ec;
  35         struct notifier_block notifier;
  36         struct cec_adapter *adap;
  37         struct cec_notifier *notify;
  38         struct cec_msg rx_msg;
  39 };
  40
  41 static void handle_cec_message(struct cros_ec_cec *cros_ec_cec)
  42 {
  43         struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec;
  44         uint8_t *cec_message = cros_ec->event_data.data.cec_message;
  45         unsigned int len = cros_ec->event_size;
  46
  47         cros_ec_cec->rx_msg.len = len;
  48         memcpy(cros_ec_cec->rx_msg.msg, cec_message, len);
  49
  50         cec_received_msg(cros_ec_cec->adap, &cros_ec_cec->rx_msg);
  51 }
  52
  53 static void handle_cec_event(struct cros_ec_cec *cros_ec_cec)
  54 {
  55         struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec;
  56         uint32_t events = cros_ec->event_data.data.cec_events;
  57
  58         if (events & EC_MKBP_CEC_SEND_OK)
  59                 cec_transmit_attempt_done(cros_ec_cec->adap,
  60                                           CEC_TX_STATUS_OK);
  61
  62         /* FW takes care of all retries, tell core to avoid more retries */
  63         if (events & EC_MKBP_CEC_SEND_FAILED)
  64                 cec_transmit_attempt_done(cros_ec_cec->adap,
  65                                           CEC_TX_STATUS_MAX_RETRIES |
  66                                           CEC_TX_STATUS_NACK);
  67 }
  68
  69 static int cros_ec_cec_event(struct notifier_block *nb,
  70                              unsigned long queued_during_suspend,
  71                              void *_notify)
  72 {
  73         struct cros_ec_cec *cros_ec_cec;
  74         struct cros_ec_device *cros_ec;
  75
  76         cros_ec_cec = container_of(nb, struct cros_ec_cec, notifier);
  77         cros_ec = cros_ec_cec->cros_ec;
  78
  79         if (cros_ec->event_data.event_type == EC_MKBP_EVENT_CEC_EVENT) {
  80                 handle_cec_event(cros_ec_cec);
  81                 return NOTIFY_OK;
  82         }
  83
  84         if (cros_ec->event_data.event_type == EC_MKBP_EVENT_CEC_MESSAGE) {
  85                 handle_cec_message(cros_ec_cec);
  86                 return NOTIFY_OK;
  87         }
  88
  89         return NOTIFY_DONE;
  90 }
  91
  92 static int cros_ec_cec_set_log_addr(struct cec_adapter *adap, u8 logical_addr)
  93 {
  94         struct cros_ec_cec *cros_ec_cec = adap->priv;
  95         struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec;
  96         struct {
  97                 struct cros_ec_command msg;
  98                 struct ec_params_cec_set data;
  99         } __packed msg = {};
 100         int ret;
 101
 102         msg.msg.command = EC_CMD_CEC_SET;
 103         msg.msg.outsize = sizeof(msg.data);
 104         msg.data.cmd = CEC_CMD_LOGICAL_ADDRESS;
 105         msg.data.val = logical_addr;
 106
 107         ret = cros_ec_cmd_xfer_status(cros_ec, &msg.msg);
 108         if (ret < 0) {
 109                 dev_err(cros_ec->dev,
 110                         "error setting CEC logical address on EC: %d\n", ret);
 111                 return ret;
 112         }
 113
 114         return 0;
 115 }
 116
 117 static int cros_ec_cec_transmit(struct cec_adapter *adap, u8 attempts,
 118                                 u32 signal_free_time, struct cec_msg *cec_msg)
 119 {
 120         struct cros_ec_cec *cros_ec_cec = adap->priv;
 121         struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec;
 122         struct {
 123                 struct cros_ec_command msg;
 124                 struct ec_params_cec_write data;
 125         } __packed msg = {};
 126         int ret;
 127
 128         msg.msg.command = EC_CMD_CEC_WRITE_MSG;
 129         msg.msg.outsize = cec_msg->len;
 130         memcpy(msg.data.msg, cec_msg->msg, cec_msg->len);
 131
 132         ret = cros_ec_cmd_xfer_status(cros_ec, &msg.msg);
 133         if (ret < 0) {
 134                 dev_err(cros_ec->dev,
 135                         "error writing CEC msg on EC: %d\n", ret);
 136                 return ret;
 137         }
 138
 139         return 0;
 140 }
 141
 142 static int cros_ec_cec_adap_enable(struct cec_adapter *adap, bool enable)
 143 {
 144         struct cros_ec_cec *cros_ec_cec = adap->priv;
 145         struct cros_ec_device *cros_ec = cros_ec_cec->cros_ec;
 146         struct {
 147                 struct cros_ec_command msg;
 148                 struct ec_params_cec_set data;
 149         } __packed msg = {};
 150         int ret;
 151
 152         msg.msg.command = EC_CMD_CEC_SET;
 153         msg.msg.outsize = sizeof(msg.data);
 154         msg.data.cmd = CEC_CMD_ENABLE;
 155         msg.data.val = enable;
 156
 157         ret = cros_ec_cmd_xfer_status(cros_ec, &msg.msg);
 158         if (ret < 0) {
 159                 dev_err(cros_ec->dev,
 160                         "error %sabling CEC on EC: %d\n",
 161                         (enable ? "en" : "dis"), ret);
 162                 return ret;
 163         }
 164
 165         return 0;
 166 }
 167
 168 static const struct cec_adap_ops cros_ec_cec_ops = {
 169         .adap_enable = cros_ec_cec_adap_enable,
 170         .adap_log_addr = cros_ec_cec_set_log_addr,
 171         .adap_transmit = cros_ec_cec_transmit,
 172 };
 173
 174 #ifdef CONFIG_PM_SLEEP
 175 static int cros_ec_cec_suspend(struct device *dev)
 176 {
 177         struct platform_device *pdev = to_platform_device(dev);
 178         struct cros_ec_cec *cros_ec_cec = dev_get_drvdata(&pdev->dev);
 179
 180         if (device_may_wakeup(dev))
 181                 enable_irq_wake(cros_ec_cec->cros_ec->irq);
 182
 183         return 0;
 184 }
 185
 186 static int cros_ec_cec_resume(struct device *dev)
 187 {
 188         struct platform_device *pdev = to_platform_device(dev);
 189         struct cros_ec_cec *cros_ec_cec = dev_get_drvdata(&pdev->dev);
 190
 191         if (device_may_wakeup(dev))
 192                 disable_irq_wake(cros_ec_cec->cros_ec->irq);
 193
 194         return 0;
 195 }
 196 #endif
 197
 198 static SIMPLE_DEV_PM_OPS(cros_ec_cec_pm_ops,
 199         cros_ec_cec_suspend, cros_ec_cec_resume);
 200
 201 #if IS_ENABLED(CONFIG_PCI) && IS_ENABLED(CONFIG_DMI)
 202
 203 /*
 204  * The Firmware only handles a single CEC interface tied to a single HDMI
 205  * connector we specify along with the DRM device name handling the HDMI output
 206  */
 207
 208 struct cec_dmi_match {
 209         char *sys_vendor;
 210         char *product_name;
 211         char *devname;
 212         char *conn;
 213 };
 214
 215 static const struct cec_dmi_match cec_dmi_match_table[] = {
 216         /* Google Fizz */
 217         { "Google", "Fizz", "0000:00:02.0", "Port B" },
 218 };
 219
 220 static int cros_ec_cec_get_notifier(struct device *dev,
 221                                     struct cec_notifier **notify)
 222 {
 223         int i;
 224
 225         for (i = 0 ; i < ARRAY_SIZE(cec_dmi_match_table) ; ++i) {
 226                 const struct cec_dmi_match *m = &cec_dmi_match_table[i];
 227
 228                 if (dmi_match(DMI_SYS_VENDOR, m->sys_vendor) &&
 229                     dmi_match(DMI_PRODUCT_NAME, m->product_name)) {
 230                         struct device *d;
 231
 232                         /* Find the device, bail out if not yet registered */
 233                         d = bus_find_device_by_name(&pci_bus_type, NULL,
 234                                                     m->devname);
 235                         if (!d)
 236                                 return -EPROBE_DEFER;
 237
 238                         *notify = cec_notifier_get_conn(d, m->conn);
 239                         return 0;
 240                 }
 241         }
 242
 243         /* Hardware support must be added in the cec_dmi_match_table */
 244         dev_warn(dev, "CEC notifier not configured for this hardware\n");
 245
 246         return -ENODEV;
 247 }
 248
 249 #else
 250
 251 static int cros_ec_cec_get_notifier(struct device *dev,
 252                                     struct cec_notifier **notify)
 253 {
 254         return -ENODEV;
 255 }
 256
 257 #endif
 258
 259 static int cros_ec_cec_probe(struct platform_device *pdev)
 260 {
 261         struct cros_ec_dev *ec_dev = dev_get_drvdata(pdev->dev.parent);
 262         struct cros_ec_device *cros_ec = ec_dev->ec_dev;
 263         struct cros_ec_cec *cros_ec_cec;
 264         int ret;
 265
 266         cros_ec_cec = devm_kzalloc(&pdev->dev, sizeof(*cros_ec_cec),
 267                                    GFP_KERNEL);
 268         if (!cros_ec_cec)
 269                 return -ENOMEM;
 270
 271         platform_set_drvdata(pdev, cros_ec_cec);
 272         cros_ec_cec->cros_ec = cros_ec;
 273
 274         ret = cros_ec_cec_get_notifier(&pdev->dev, &cros_ec_cec->notify);
 275         if (ret)
 276                 return ret;
 277
 278         ret = device_init_wakeup(&pdev->dev, 1);
 279         if (ret) {
 280                 dev_err(&pdev->dev, "failed to initialize wakeup\n");
 281                 return ret;
 282         }
 283
 284         cros_ec_cec->adap = cec_allocate_adapter(&cros_ec_cec_ops, cros_ec_cec,
 285                                                  DRV_NAME, CEC_CAP_DEFAULTS, 1);
 286         if (IS_ERR(cros_ec_cec->adap))
 287                 return PTR_ERR(cros_ec_cec->adap);
 288
 289         /* Get CEC events from the EC. */
 290         cros_ec_cec->notifier.notifier_call = cros_ec_cec_event;
 291         ret = blocking_notifier_chain_register(&cros_ec->event_notifier,
 292                                                &cros_ec_cec->notifier);
 293         if (ret) {
 294                 dev_err(&pdev->dev, "failed to register notifier\n");
 295                 cec_delete_adapter(cros_ec_cec->adap);
 296                 return ret;
 297         }
 298
 299         ret = cec_register_adapter(cros_ec_cec->adap, &pdev->dev);
 300         if (ret < 0) {
 301                 cec_delete_adapter(cros_ec_cec->adap);
 302                 return ret;
 303         }
 304
 305         cec_register_cec_notifier(cros_ec_cec->adap, cros_ec_cec->notify);
 306
 307         return 0;
 308 }
 309
 310 static int cros_ec_cec_remove(struct platform_device *pdev)
 311 {
 312         struct cros_ec_cec *cros_ec_cec = platform_get_drvdata(pdev);
 313         struct device *dev = &pdev->dev;
 314         int ret;
 315
 316         ret = blocking_notifier_chain_unregister(
 317                         &cros_ec_cec->cros_ec->event_notifier,
 318                         &cros_ec_cec->notifier);
 319
 320         if (ret) {
 321                 dev_err(dev, "failed to unregister notifier\n");
 322                 return ret;
 323         }
 324
 325         cec_unregister_adapter(cros_ec_cec->adap);
 326
 327         if (cros_ec_cec->notify)
 328                 cec_notifier_put(cros_ec_cec->notify);
 329
 330         return 0;
 331 }
 332
 333 static struct platform_driver cros_ec_cec_driver = {
 334         .probe = cros_ec_cec_probe,
 335         .remove  = cros_ec_cec_remove,
 336         .driver = {
 337                 .name = DRV_NAME,
 338                 .pm = &cros_ec_cec_pm_ops,
 339         },
 340 };
 341
 342 module_platform_driver(cros_ec_cec_driver);
 343
 344 MODULE_DESCRIPTION("CEC driver for ChromeOS ECs");
 345 MODULE_AUTHOR("Neil Armstrong <narmstrong@baylibre.com>");
 346 MODULE_LICENSE("GPL");
 347 MODULE_ALIAS("platform:" DRV_NAME);