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@@ -0,0 +1,201 @@
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+/*
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+ * ChromeOS EC multi-function device (I2C)
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+ *
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+ * Copyright (C) 2012 Google, Inc
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+ *
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+ * This software is licensed under the terms of the GNU General Public
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+ * License version 2, as published by the Free Software Foundation, and
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+ * may be copied, distributed, and modified under those terms.
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+ *
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+ * This program is distributed in the hope that it will be useful,
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+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
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+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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+ * GNU General Public License for more details.
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+ */
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+
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+#include <linux/kernel.h>
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+#include <linux/module.h>
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+#include <linux/i2c.h>
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+#include <linux/interrupt.h>
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+#include <linux/mfd/cros_ec.h>
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+#include <linux/mfd/cros_ec_commands.h>
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+#include <linux/platform_device.h>
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+#include <linux/slab.h>
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+
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+static inline struct cros_ec_device *to_ec_dev(struct device *dev)
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+{
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+ struct i2c_client *client = to_i2c_client(dev);
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+
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+ return i2c_get_clientdata(client);
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+}
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+
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+static int cros_ec_command_xfer(struct cros_ec_device *ec_dev,
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+ struct cros_ec_msg *msg)
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+{
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+ struct i2c_client *client = ec_dev->priv;
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+ int ret = -ENOMEM;
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+ int i;
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+ int packet_len;
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+ u8 *out_buf = NULL;
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+ u8 *in_buf = NULL;
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+ u8 sum;
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+ struct i2c_msg i2c_msg[2];
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+
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+ i2c_msg[0].addr = client->addr;
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+ i2c_msg[0].flags = 0;
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+ i2c_msg[1].addr = client->addr;
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+ i2c_msg[1].flags = I2C_M_RD;
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+
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+ /*
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+ * allocate larger packet (one byte for checksum, one byte for
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+ * length, and one for result code)
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+ */
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+ packet_len = msg->in_len + 3;
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+ in_buf = kzalloc(packet_len, GFP_KERNEL);
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+ if (!in_buf)
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+ goto done;
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+ i2c_msg[1].len = packet_len;
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+ i2c_msg[1].buf = (char *)in_buf;
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+
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+ /*
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+ * allocate larger packet (one byte for checksum, one for
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+ * command code, one for length, and one for command version)
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+ */
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+ packet_len = msg->out_len + 4;
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+ out_buf = kzalloc(packet_len, GFP_KERNEL);
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+ if (!out_buf)
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+ goto done;
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+ i2c_msg[0].len = packet_len;
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+ i2c_msg[0].buf = (char *)out_buf;
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+
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+ out_buf[0] = EC_CMD_VERSION0 + msg->version;
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+ out_buf[1] = msg->cmd;
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+ out_buf[2] = msg->out_len;
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+
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+ /* copy message payload and compute checksum */
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+ sum = out_buf[0] + out_buf[1] + out_buf[2];
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+ for (i = 0; i < msg->out_len; i++) {
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+ out_buf[3 + i] = msg->out_buf[i];
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+ sum += out_buf[3 + i];
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+ }
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+ out_buf[3 + msg->out_len] = sum;
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+
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+ /* send command to EC and read answer */
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+ ret = i2c_transfer(client->adapter, i2c_msg, 2);
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+ if (ret < 0) {
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+ dev_err(ec_dev->dev, "i2c transfer failed: %d\n", ret);
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+ goto done;
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+ } else if (ret != 2) {
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+ dev_err(ec_dev->dev, "failed to get response: %d\n", ret);
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+ ret = -EIO;
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+ goto done;
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+ }
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+
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+ /* check response error code */
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+ if (i2c_msg[1].buf[0]) {
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+ dev_warn(ec_dev->dev, "command 0x%02x returned an error %d\n",
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+ msg->cmd, i2c_msg[1].buf[0]);
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+ ret = -EINVAL;
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+ goto done;
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+ }
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+
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+ /* copy response packet payload and compute checksum */
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+ sum = in_buf[0] + in_buf[1];
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+ for (i = 0; i < msg->in_len; i++) {
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+ msg->in_buf[i] = in_buf[2 + i];
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+ sum += in_buf[2 + i];
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+ }
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+ dev_dbg(ec_dev->dev, "packet: %*ph, sum = %02x\n",
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+ i2c_msg[1].len, in_buf, sum);
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+ if (sum != in_buf[2 + msg->in_len]) {
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+ dev_err(ec_dev->dev, "bad packet checksum\n");
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+ ret = -EBADMSG;
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+ goto done;
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+ }
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+
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+ ret = 0;
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+ done:
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+ kfree(in_buf);
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+ kfree(out_buf);
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+ return ret;
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+}
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+
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+static int cros_ec_probe_i2c(struct i2c_client *client,
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+ const struct i2c_device_id *dev_id)
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+{
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+ struct device *dev = &client->dev;
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+ struct cros_ec_device *ec_dev = NULL;
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+ int err;
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+
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+ ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
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+ if (!ec_dev)
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+ return -ENOMEM;
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+
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+ i2c_set_clientdata(client, ec_dev);
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+ ec_dev->name = "I2C";
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+ ec_dev->dev = dev;
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+ ec_dev->priv = client;
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+ ec_dev->irq = client->irq;
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+ ec_dev->command_xfer = cros_ec_command_xfer;
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+ ec_dev->ec_name = client->name;
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+ ec_dev->phys_name = client->adapter->name;
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+ ec_dev->parent = &client->dev;
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+
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+ err = cros_ec_register(ec_dev);
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+ if (err) {
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+ dev_err(dev, "cannot register EC\n");
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+ return err;
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+ }
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+
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+ return 0;
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+}
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+
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+static int cros_ec_remove_i2c(struct i2c_client *client)
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+{
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+ struct cros_ec_device *ec_dev = i2c_get_clientdata(client);
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+
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+ cros_ec_remove(ec_dev);
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+
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+ return 0;
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+}
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+
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+#ifdef CONFIG_PM_SLEEP
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+static int cros_ec_i2c_suspend(struct device *dev)
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+{
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+ struct cros_ec_device *ec_dev = to_ec_dev(dev);
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+
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+ return cros_ec_suspend(ec_dev);
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+}
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+
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+static int cros_ec_i2c_resume(struct device *dev)
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+{
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+ struct cros_ec_device *ec_dev = to_ec_dev(dev);
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+
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+ return cros_ec_resume(ec_dev);
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+}
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+#endif
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+
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+static SIMPLE_DEV_PM_OPS(cros_ec_i2c_pm_ops, cros_ec_i2c_suspend,
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+ cros_ec_i2c_resume);
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+
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+static const struct i2c_device_id cros_ec_i2c_id[] = {
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+ { "cros-ec-i2c", 0 },
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+ { }
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+};
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+MODULE_DEVICE_TABLE(i2c, cros_ec_i2c_id);
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+
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+static struct i2c_driver cros_ec_driver = {
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+ .driver = {
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+ .name = "cros-ec-i2c",
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+ .owner = THIS_MODULE,
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+ .pm = &cros_ec_i2c_pm_ops,
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+ },
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+ .probe = cros_ec_probe_i2c,
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+ .remove = cros_ec_remove_i2c,
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+ .id_table = cros_ec_i2c_id,
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+};
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+
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+module_i2c_driver(cros_ec_driver);
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+
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+MODULE_LICENSE("GPL");
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+MODULE_DESCRIPTION("ChromeOS EC multi function device");
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