drivers/mfd/cros_ec.c

   1 /*
   2  * ChromeOS EC multi-function device
   3  *
   4  * Copyright (C) 2012 Google, Inc
   5  *
   6  * This software is licensed under the terms of the GNU General Public
   7  * License version 2, as published by the Free Software Foundation, and
   8  * may be copied, distributed, and modified under those terms.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * The ChromeOS EC multi function device is used to mux all the requests
  16  * to the EC device for its multiple features: keyboard controller,
  17  * battery charging and regulator control, firmware update.
  18  */
  19
  20 #include <linux/of_platform.h>
  21 #include <linux/interrupt.h>
  22 #include <linux/slab.h>
  23 #include <linux/module.h>
  24 #include <linux/mfd/core.h>
  25 #include <linux/mfd/cros_ec.h>
  26
  27 #define CROS_EC_DEV_EC_INDEX 0
  28 #define CROS_EC_DEV_PD_INDEX 1
  29
  30 static struct cros_ec_platform ec_p = {
  31         .ec_name = CROS_EC_DEV_NAME,
  32         .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_EC_INDEX),
  33 };
  34
  35 static struct cros_ec_platform pd_p = {
  36         .ec_name = CROS_EC_DEV_PD_NAME,
  37         .cmd_offset = EC_CMD_PASSTHRU_OFFSET(CROS_EC_DEV_PD_INDEX),
  38 };
  39
  40 static const struct mfd_cell ec_cell = {
  41         .name = "cros-ec-ctl",
  42         .platform_data = &ec_p,
  43         .pdata_size = sizeof(ec_p),
  44 };
  45
  46 static const struct mfd_cell ec_pd_cell = {
  47         .name = "cros-ec-ctl",
  48         .platform_data = &pd_p,
  49         .pdata_size = sizeof(pd_p),
  50 };
  51
  52 int cros_ec_register(struct cros_ec_device *ec_dev)
  53 {
  54         struct device *dev = ec_dev->dev;
  55         int err = 0;
  56
  57         ec_dev->max_request = sizeof(struct ec_params_hello);
  58         ec_dev->max_response = sizeof(struct ec_response_get_protocol_info);
  59         ec_dev->max_passthru = 0;
  60
  61         ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
  62         if (!ec_dev->din)
  63                 return -ENOMEM;
  64
  65         ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
  66         if (!ec_dev->dout)
  67                 return -ENOMEM;
  68
  69         mutex_init(&ec_dev->lock);
  70
  71         err = cros_ec_query_all(ec_dev);
  72         if (err) {
  73                 dev_err(dev, "Cannot identify the EC: error %d\n", err);
  74                 return err;
  75         }
  76
  77         err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO, &ec_cell, 1,
  78                               NULL, ec_dev->irq, NULL);
  79         if (err) {
  80                 dev_err(dev,
  81                         "Failed to register Embedded Controller subdevice %d\n",
  82                         err);
  83                 return err;
  84         }
  85
  86         if (ec_dev->max_passthru) {
  87                 /*
  88                  * Register a PD device as well on top of this device.
  89                  * We make the following assumptions:
  90                  * - behind an EC, we have a pd
  91                  * - only one device added.
  92                  * - the EC is responsive at init time (it is not true for a
  93                  *   sensor hub.
  94                  */
  95                 err = mfd_add_devices(ec_dev->dev, PLATFORM_DEVID_AUTO,
  96                                       &ec_pd_cell, 1, NULL, ec_dev->irq, NULL);
  97                 if (err) {
  98                         dev_err(dev,
  99                                 "Failed to register Power Delivery subdevice %d\n",
 100                                 err);
 101                         return err;
 102                 }
 103         }
 104
 105         if (IS_ENABLED(CONFIG_OF) && dev->of_node) {
 106                 err = of_platform_populate(dev->of_node, NULL, NULL, dev);
 107                 if (err) {
 108                         mfd_remove_devices(dev);
 109                         dev_err(dev, "Failed to register sub-devices\n");
 110                         return err;
 111                 }
 112         }
 113
 114         dev_info(dev, "Chrome EC device registered\n");
 115
 116         return 0;
 117 }
 118 EXPORT_SYMBOL(cros_ec_register);
 119
 120 int cros_ec_remove(struct cros_ec_device *ec_dev)
 121 {
 122         mfd_remove_devices(ec_dev->dev);
 123
 124         return 0;
 125 }
 126 EXPORT_SYMBOL(cros_ec_remove);
 127
 128 #ifdef CONFIG_PM_SLEEP
 129 int cros_ec_suspend(struct cros_ec_device *ec_dev)
 130 {
 131         struct device *dev = ec_dev->dev;
 132
 133         if (device_may_wakeup(dev))
 134                 ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
 135
 136         disable_irq(ec_dev->irq);
 137         ec_dev->was_wake_device = ec_dev->wake_enabled;
 138
 139         return 0;
 140 }
 141 EXPORT_SYMBOL(cros_ec_suspend);
 142
 143 int cros_ec_resume(struct cros_ec_device *ec_dev)
 144 {
 145         enable_irq(ec_dev->irq);
 146
 147         if (ec_dev->wake_enabled) {
 148                 disable_irq_wake(ec_dev->irq);
 149                 ec_dev->wake_enabled = 0;
 150         }
 151
 152         return 0;
 153 }
 154 EXPORT_SYMBOL(cros_ec_resume);
 155
 156 #endif
 157
 158 MODULE_LICENSE("GPL");
 159 MODULE_DESCRIPTION("ChromeOS EC core driver");