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@@ -0,0 +1,268 @@
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+/*
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+ * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
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+ *
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+ * Copyright (C) 2014 Google, Inc.
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+ *
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+ * This program is free software; you can redistribute it and/or modify
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+ * it under the terms of the GNU General Public License as published by
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+ * the Free Software Foundation; either version 2 of the License, or
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+ * (at your option) any later version.
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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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+ * You should have received a copy of the GNU General Public License
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+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
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+ */
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+
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+#include <linux/fs.h>
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+#include <linux/module.h>
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+#include <linux/platform_device.h>
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+#include <linux/uaccess.h>
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+
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+#include "cros_ec_dev.h"
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+
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+/* Device variables */
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+#define CROS_MAX_DEV 128
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+static struct class *cros_class;
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+static int ec_major;
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+
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+/* Basic communication */
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+static int ec_get_version(struct cros_ec_device *ec, char *str, int maxlen)
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+{
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+ struct ec_response_get_version *resp;
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+ static const char * const current_image_name[] = {
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+ "unknown", "read-only", "read-write", "invalid",
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+ };
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+ struct cros_ec_command msg = {
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+ .version = 0,
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+ .command = EC_CMD_GET_VERSION,
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+ .outdata = { 0 },
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+ .outsize = 0,
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+ .indata = { 0 },
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+ .insize = sizeof(*resp),
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+ };
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+ int ret;
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+
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+ ret = cros_ec_cmd_xfer(ec, &msg);
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+ if (ret < 0)
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+ return ret;
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+
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+ if (msg.result != EC_RES_SUCCESS) {
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+ snprintf(str, maxlen,
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+ "%s\nUnknown EC version: EC returned %d\n",
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+ CROS_EC_DEV_VERSION, msg.result);
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+ return 0;
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+ }
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+
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+ resp = (struct ec_response_get_version *)msg.indata;
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+ if (resp->current_image >= ARRAY_SIZE(current_image_name))
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+ resp->current_image = 3; /* invalid */
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+
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+ snprintf(str, maxlen, "%s\n%s\n%s\n\%s\n", CROS_EC_DEV_VERSION,
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+ resp->version_string_ro, resp->version_string_rw,
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+ current_image_name[resp->current_image]);
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+
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+ return 0;
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+}
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+
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+/* Device file ops */
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+static int ec_device_open(struct inode *inode, struct file *filp)
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+{
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+ filp->private_data = container_of(inode->i_cdev,
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+ struct cros_ec_device, cdev);
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+ return 0;
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+}
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+
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+static int ec_device_release(struct inode *inode, struct file *filp)
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+{
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+ return 0;
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+}
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+
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+static ssize_t ec_device_read(struct file *filp, char __user *buffer,
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+ size_t length, loff_t *offset)
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+{
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+ struct cros_ec_device *ec = filp->private_data;
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+ char msg[sizeof(struct ec_response_get_version) +
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+ sizeof(CROS_EC_DEV_VERSION)];
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+ size_t count;
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+ int ret;
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+
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+ if (*offset != 0)
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+ return 0;
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+
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+ ret = ec_get_version(ec, msg, sizeof(msg));
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+ if (ret)
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+ return ret;
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+
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+ count = min(length, strlen(msg));
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+
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+ if (copy_to_user(buffer, msg, count))
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+ return -EFAULT;
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+
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+ *offset = count;
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+ return count;
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+}
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+
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+/* Ioctls */
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+static long ec_device_ioctl_xcmd(struct cros_ec_device *ec, void __user *arg)
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+{
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+ long ret;
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+ struct cros_ec_command s_cmd = { };
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+
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+ if (copy_from_user(&s_cmd, arg, sizeof(s_cmd)))
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+ return -EFAULT;
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+
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+ ret = cros_ec_cmd_xfer(ec, &s_cmd);
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+ /* Only copy data to userland if data was received. */
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+ if (ret < 0)
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+ return ret;
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+
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+ if (copy_to_user(arg, &s_cmd, sizeof(s_cmd)))
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+ return -EFAULT;
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+
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+ return 0;
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+}
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+
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+static long ec_device_ioctl_readmem(struct cros_ec_device *ec, void __user *arg)
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+{
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+ struct cros_ec_readmem s_mem = { };
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+ long num;
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+
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+ /* Not every platform supports direct reads */
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+ if (!ec->cmd_readmem)
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+ return -ENOTTY;
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+
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+ if (copy_from_user(&s_mem, arg, sizeof(s_mem)))
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+ return -EFAULT;
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+
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+ num = ec->cmd_readmem(ec, s_mem.offset, s_mem.bytes, s_mem.buffer);
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+ if (num <= 0)
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+ return num;
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+
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+ if (copy_to_user((void __user *)arg, &s_mem, sizeof(s_mem)))
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+ return -EFAULT;
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+
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+ return 0;
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+}
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+
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+static long ec_device_ioctl(struct file *filp, unsigned int cmd,
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+ unsigned long arg)
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+{
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+ struct cros_ec_device *ec = filp->private_data;
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+
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+ if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC)
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+ return -ENOTTY;
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+
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+ switch (cmd) {
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+ case CROS_EC_DEV_IOCXCMD:
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+ return ec_device_ioctl_xcmd(ec, (void __user *)arg);
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+ case CROS_EC_DEV_IOCRDMEM:
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+ return ec_device_ioctl_readmem(ec, (void __user *)arg);
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+ }
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+
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+ return -ENOTTY;
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+}
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+
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+/* Module initialization */
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+static const struct file_operations fops = {
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+ .open = ec_device_open,
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+ .release = ec_device_release,
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+ .read = ec_device_read,
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+ .unlocked_ioctl = ec_device_ioctl,
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+};
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+
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+static int ec_device_probe(struct platform_device *pdev)
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+{
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+ struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
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+ int retval = -ENOTTY;
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+ dev_t devno = MKDEV(ec_major, 0);
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+
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+ /* Instantiate it (and remember the EC) */
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+ cdev_init(&ec->cdev, &fops);
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+
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+ retval = cdev_add(&ec->cdev, devno, 1);
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+ if (retval) {
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+ dev_err(&pdev->dev, ": failed to add character device\n");
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+ return retval;
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+ }
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+
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+ ec->vdev = device_create(cros_class, NULL, devno, ec,
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+ CROS_EC_DEV_NAME);
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+ if (IS_ERR(ec->vdev)) {
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+ retval = PTR_ERR(ec->vdev);
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+ dev_err(&pdev->dev, ": failed to create device\n");
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+ cdev_del(&ec->cdev);
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+ return retval;
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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 ec_device_remove(struct platform_device *pdev)
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+{
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+ struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
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+
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+ device_destroy(cros_class, MKDEV(ec_major, 0));
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+ cdev_del(&ec->cdev);
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+ return 0;
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+}
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+
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+static struct platform_driver cros_ec_dev_driver = {
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+ .driver = {
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+ .name = "cros-ec-ctl",
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+ },
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+ .probe = ec_device_probe,
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+ .remove = ec_device_remove,
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+};
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+
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+static int __init cros_ec_dev_init(void)
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+{
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+ int ret;
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+ dev_t dev = 0;
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+
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+ cros_class = class_create(THIS_MODULE, "chromeos");
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+ if (IS_ERR(cros_class)) {
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+ pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
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+ return PTR_ERR(cros_class);
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+ }
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+
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+ /* Get a range of minor numbers (starting with 0) to work with */
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+ ret = alloc_chrdev_region(&dev, 0, CROS_MAX_DEV, CROS_EC_DEV_NAME);
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+ if (ret < 0) {
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+ pr_err(CROS_EC_DEV_NAME ": alloc_chrdev_region() failed\n");
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+ goto failed_chrdevreg;
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+ }
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+ ec_major = MAJOR(dev);
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+
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+ /* Register the driver */
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+ ret = platform_driver_register(&cros_ec_dev_driver);
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+ if (ret < 0) {
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+ pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
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+ goto failed_devreg;
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+ }
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+ return 0;
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+
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+failed_devreg:
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+ unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV);
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+failed_chrdevreg:
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+ class_destroy(cros_class);
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+ return ret;
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+}
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+
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+static void __exit cros_ec_dev_exit(void)
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+{
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+ platform_driver_unregister(&cros_ec_dev_driver);
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+ unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
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+ class_destroy(cros_class);
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+}
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+
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+module_init(cros_ec_dev_init);
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+module_exit(cros_ec_dev_exit);
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+
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+MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
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+MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
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+MODULE_VERSION("1.0");
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+MODULE_LICENSE("GPL");
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Bill Richardson