--- /dev/null
+/*
+ * ChromeOS EC multi-function device
+ *
+ * Copyright (C) 2012 Google, Inc
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * The ChromeOS EC multi function device is used to mux all the requests
+ * to the EC device for its multiple features: keyboard controller,
+ * battery charging and regulator control, firmware update.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/cros_ec.h>
+#include <linux/mfd/cros_ec_commands.h>
+#include <linux/delay.h>
+
+#define EC_COMMAND_RETRIES 50
+
+int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
+ struct cros_ec_command *msg)
+{
+ uint8_t *out;
+ int csum, i;
+
+ BUG_ON(msg->outsize > EC_PROTO2_MAX_PARAM_SIZE);
+ out = ec_dev->dout;
+ out[0] = EC_CMD_VERSION0 + msg->version;
+ out[1] = msg->command;
+ out[2] = msg->outsize;
+ csum = out[0] + out[1] + out[2];
+ for (i = 0; i < msg->outsize; i++)
+ csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->outdata[i];
+ out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = (uint8_t)(csum & 0xff);
+
+ return EC_MSG_TX_PROTO_BYTES + msg->outsize;
+}
+EXPORT_SYMBOL(cros_ec_prepare_tx);
+
+int cros_ec_check_result(struct cros_ec_device *ec_dev,
+ struct cros_ec_command *msg)
+{
+ switch (msg->result) {
+ case EC_RES_SUCCESS:
+ return 0;
+ case EC_RES_IN_PROGRESS:
+ dev_dbg(ec_dev->dev, "command 0x%02x in progress\n",
+ msg->command);
+ return -EAGAIN;
+ default:
+ dev_dbg(ec_dev->dev, "command 0x%02x returned %d\n",
+ msg->command, msg->result);
+ return 0;
+ }
+}
+EXPORT_SYMBOL(cros_ec_check_result);
+
+int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
+ struct cros_ec_command *msg)
+{
+ int ret;
+
+ mutex_lock(&ec_dev->lock);
+ ret = ec_dev->cmd_xfer(ec_dev, msg);
+ if (msg->result == EC_RES_IN_PROGRESS) {
+ int i;
+ struct cros_ec_command status_msg = { };
+ struct ec_response_get_comms_status *status;
+
+ status_msg.command = EC_CMD_GET_COMMS_STATUS;
+ status_msg.insize = sizeof(*status);
+
+ /*
+ * Query the EC's status until it's no longer busy or
+ * we encounter an error.
+ */
+ for (i = 0; i < EC_COMMAND_RETRIES; i++) {
+ usleep_range(10000, 11000);
+
+ ret = ec_dev->cmd_xfer(ec_dev, &status_msg);
+ if (ret < 0)
+ break;
+
+ msg->result = status_msg.result;
+ if (status_msg.result != EC_RES_SUCCESS)
+ break;
+
+ status = (struct ec_response_get_comms_status *)
+ status_msg.indata;
+ if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
+ break;
+ }
+ }
+ mutex_unlock(&ec_dev->lock);
+
+ return ret;
+}
+EXPORT_SYMBOL(cros_ec_cmd_xfer);
+
+static const struct mfd_cell cros_devs[] = {
+ {
+ .name = "cros-ec-keyb",
+ .id = 1,
+ .of_compatible = "google,cros-ec-keyb",
+ },
+ {
+ .name = "cros-ec-i2c-tunnel",
+ .id = 2,
+ .of_compatible = "google,cros-ec-i2c-tunnel",
+ },
+ {
+ .name = "cros-ec-ctl",
+ .id = 3,
+ },
+};
+
+int cros_ec_register(struct cros_ec_device *ec_dev)
+{
+ struct device *dev = ec_dev->dev;
+ int err = 0;
+
+ if (ec_dev->din_size) {
+ ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL);
+ if (!ec_dev->din)
+ return -ENOMEM;
+ }
+ if (ec_dev->dout_size) {
+ ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL);
+ if (!ec_dev->dout)
+ return -ENOMEM;
+ }
+
+ mutex_init(&ec_dev->lock);
+
+ err = mfd_add_devices(dev, 0, cros_devs,
+ ARRAY_SIZE(cros_devs),
+ NULL, ec_dev->irq, NULL);
+ if (err) {
+ dev_err(dev, "failed to add mfd devices\n");
+ return err;
+ }
+
+ dev_info(dev, "Chrome EC device registered\n");
+
+ return 0;
+}
+EXPORT_SYMBOL(cros_ec_register);
+
+int cros_ec_remove(struct cros_ec_device *ec_dev)
+{
+ mfd_remove_devices(ec_dev->dev);
+
+ return 0;
+}
+EXPORT_SYMBOL(cros_ec_remove);
+
+#ifdef CONFIG_PM_SLEEP
+int cros_ec_suspend(struct cros_ec_device *ec_dev)
+{
+ struct device *dev = ec_dev->dev;
+
+ if (device_may_wakeup(dev))
+ ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq);
+
+ disable_irq(ec_dev->irq);
+ ec_dev->was_wake_device = ec_dev->wake_enabled;
+
+ return 0;
+}
+EXPORT_SYMBOL(cros_ec_suspend);
+
+int cros_ec_resume(struct cros_ec_device *ec_dev)
+{
+ enable_irq(ec_dev->irq);
+
+ if (ec_dev->wake_enabled) {
+ disable_irq_wake(ec_dev->irq);
+ ec_dev->wake_enabled = 0;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL(cros_ec_resume);
+
+#endif
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ChromeOS EC core driver");
Code Review / kvmfornfv.git / blobdiff