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authorLinus Torvalds <torvalds@linux-foundation.org>2015-04-26 23:36:02 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2015-04-26 23:36:02 +0300
commit36a8032d77649430f5ef11fbf0df2bb026be0b04 (patch)
tree18e386a957bde5f71e9efd2cddf1d8aadafe48e4 /drivers/platform/chrome/cros_ec_dev.c
parent7f9f44308c8993c9ab8078d174dad34bea3e82d7 (diff)
parent96cba9b00e297303774bec59e192064d20adeb3d (diff)
downloadlinux-36a8032d77649430f5ef11fbf0df2bb026be0b04.tar.xz
Merge tag 'chrome-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/olof/chrome-platform
Pull chrome platform updates from Olof Johansson: "Here's a set of updates to the Chrome OS platform drivers for this merge window. Main new things this cycle is: - Driver changes to expose the lightbar to users. With this, you can make your own blinkenlights on Chromebook Pixels. - Changes in the way that the atmel_mxt trackpads are probed. The laptop driver is trying to be smart and not instantiate the devices that don't answer to probe. For the trackpad that can come up in two modes (bootloader or regular), this gets complicated since the driver already knows how to handle the two modes including the actual addresses used. So now the laptop driver needs to know more too, instantiating the regular address even if the bootloader one is the probe that passed. - mfd driver improvements by Javier Martines Canillas, and a few bugfixes from him, kbuild and myself" * tag 'chrome-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/olof/chrome-platform: platform/chrome: chromeos_laptop - instantiate Atmel at primary address platform/chrome: cros_ec_lpc - Depend on X86 || COMPILE_TEST platform/chrome: cros_ec_lpc - Include linux/io.h header file platform/chrome: fix platform_no_drv_owner.cocci warnings platform/chrome: cros_ec_lightbar - fix duplicate const warning platform/chrome: cros_ec_dev - fix Unknown escape '%' warning platform/chrome: Expose Chrome OS Lightbar to users platform/chrome: Create sysfs attributes for the ChromeOS EC mfd: cros_ec: Instantiate ChromeOS EC character device platform/chrome: Add Chrome OS EC userspace device interface platform/chrome: Add cros_ec_lpc driver for x86 devices mfd: cros_ec: Add char dev and virtual dev pointers mfd: cros_ec: Use fixed size arrays to transfer data with the EC
Diffstat (limited to 'drivers/platform/chrome/cros_ec_dev.c')
-rw-r--r--drivers/platform/chrome/cros_ec_dev.c274
1 files changed, 274 insertions, 0 deletions
diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
new file mode 100644
index 000000000000..6090d0b2826f
--- /dev/null
+++ b/drivers/platform/chrome/cros_ec_dev.c
@@ -0,0 +1,274 @@
+/*
+ * cros_ec_dev - expose the Chrome OS Embedded Controller to user-space
+ *
+ * Copyright (C) 2014 Google, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/fs.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/uaccess.h>
+
+#include "cros_ec_dev.h"
+
+/* Device variables */
+#define CROS_MAX_DEV 128
+static struct class *cros_class;
+static int ec_major;
+
+/* Basic communication */
+static int ec_get_version(struct cros_ec_device *ec, char *str, int maxlen)
+{
+ struct ec_response_get_version *resp;
+ static const char * const current_image_name[] = {
+ "unknown", "read-only", "read-write", "invalid",
+ };
+ struct cros_ec_command msg = {
+ .version = 0,
+ .command = EC_CMD_GET_VERSION,
+ .outdata = { 0 },
+ .outsize = 0,
+ .indata = { 0 },
+ .insize = sizeof(*resp),
+ };
+ int ret;
+
+ ret = cros_ec_cmd_xfer(ec, &msg);
+ if (ret < 0)
+ return ret;
+
+ if (msg.result != EC_RES_SUCCESS) {
+ snprintf(str, maxlen,
+ "%s\nUnknown EC version: EC returned %d\n",
+ CROS_EC_DEV_VERSION, msg.result);
+ return 0;
+ }
+
+ resp = (struct ec_response_get_version *)msg.indata;
+ if (resp->current_image >= ARRAY_SIZE(current_image_name))
+ resp->current_image = 3; /* invalid */
+
+ snprintf(str, maxlen, "%s\n%s\n%s\n%s\n", CROS_EC_DEV_VERSION,
+ resp->version_string_ro, resp->version_string_rw,
+ current_image_name[resp->current_image]);
+
+ return 0;
+}
+
+/* Device file ops */
+static int ec_device_open(struct inode *inode, struct file *filp)
+{
+ filp->private_data = container_of(inode->i_cdev,
+ struct cros_ec_device, cdev);
+ return 0;
+}
+
+static int ec_device_release(struct inode *inode, struct file *filp)
+{
+ return 0;
+}
+
+static ssize_t ec_device_read(struct file *filp, char __user *buffer,
+ size_t length, loff_t *offset)
+{
+ struct cros_ec_device *ec = filp->private_data;
+ char msg[sizeof(struct ec_response_get_version) +
+ sizeof(CROS_EC_DEV_VERSION)];
+ size_t count;
+ int ret;
+
+ if (*offset != 0)
+ return 0;
+
+ ret = ec_get_version(ec, msg, sizeof(msg));
+ if (ret)
+ return ret;
+
+ count = min(length, strlen(msg));
+
+ if (copy_to_user(buffer, msg, count))
+ return -EFAULT;
+
+ *offset = count;
+ return count;
+}
+
+/* Ioctls */
+static long ec_device_ioctl_xcmd(struct cros_ec_device *ec, void __user *arg)
+{
+ long ret;
+ struct cros_ec_command s_cmd = { };
+
+ if (copy_from_user(&s_cmd, arg, sizeof(s_cmd)))
+ return -EFAULT;
+
+ ret = cros_ec_cmd_xfer(ec, &s_cmd);
+ /* Only copy data to userland if data was received. */
+ if (ret < 0)
+ return ret;
+
+ if (copy_to_user(arg, &s_cmd, sizeof(s_cmd)))
+ return -EFAULT;
+
+ return 0;
+}
+
+static long ec_device_ioctl_readmem(struct cros_ec_device *ec, void __user *arg)
+{
+ struct cros_ec_readmem s_mem = { };
+ long num;
+
+ /* Not every platform supports direct reads */
+ if (!ec->cmd_readmem)
+ return -ENOTTY;
+
+ if (copy_from_user(&s_mem, arg, sizeof(s_mem)))
+ return -EFAULT;
+
+ num = ec->cmd_readmem(ec, s_mem.offset, s_mem.bytes, s_mem.buffer);
+ if (num <= 0)
+ return num;
+
+ if (copy_to_user((void __user *)arg, &s_mem, sizeof(s_mem)))
+ return -EFAULT;
+
+ return 0;
+}
+
+static long ec_device_ioctl(struct file *filp, unsigned int cmd,
+ unsigned long arg)
+{
+ struct cros_ec_device *ec = filp->private_data;
+
+ if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC)
+ return -ENOTTY;
+
+ switch (cmd) {
+ case CROS_EC_DEV_IOCXCMD:
+ return ec_device_ioctl_xcmd(ec, (void __user *)arg);
+ case CROS_EC_DEV_IOCRDMEM:
+ return ec_device_ioctl_readmem(ec, (void __user *)arg);
+ }
+
+ return -ENOTTY;
+}
+
+/* Module initialization */
+static const struct file_operations fops = {
+ .open = ec_device_open,
+ .release = ec_device_release,
+ .read = ec_device_read,
+ .unlocked_ioctl = ec_device_ioctl,
+};
+
+static int ec_device_probe(struct platform_device *pdev)
+{
+ struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
+ int retval = -ENOTTY;
+ dev_t devno = MKDEV(ec_major, 0);
+
+ /* Instantiate it (and remember the EC) */
+ cdev_init(&ec->cdev, &fops);
+
+ retval = cdev_add(&ec->cdev, devno, 1);
+ if (retval) {
+ dev_err(&pdev->dev, ": failed to add character device\n");
+ return retval;
+ }
+
+ ec->vdev = device_create(cros_class, NULL, devno, ec,
+ CROS_EC_DEV_NAME);
+ if (IS_ERR(ec->vdev)) {
+ retval = PTR_ERR(ec->vdev);
+ dev_err(&pdev->dev, ": failed to create device\n");
+ cdev_del(&ec->cdev);
+ return retval;
+ }
+
+ /* Initialize extra interfaces */
+ ec_dev_sysfs_init(ec);
+ ec_dev_lightbar_init(ec);
+
+ return 0;
+}
+
+static int ec_device_remove(struct platform_device *pdev)
+{
+ struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
+
+ ec_dev_lightbar_remove(ec);
+ ec_dev_sysfs_remove(ec);
+ device_destroy(cros_class, MKDEV(ec_major, 0));
+ cdev_del(&ec->cdev);
+ return 0;
+}
+
+static struct platform_driver cros_ec_dev_driver = {
+ .driver = {
+ .name = "cros-ec-ctl",
+ },
+ .probe = ec_device_probe,
+ .remove = ec_device_remove,
+};
+
+static int __init cros_ec_dev_init(void)
+{
+ int ret;
+ dev_t dev = 0;
+
+ cros_class = class_create(THIS_MODULE, "chromeos");
+ if (IS_ERR(cros_class)) {
+ pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
+ return PTR_ERR(cros_class);
+ }
+
+ /* Get a range of minor numbers (starting with 0) to work with */
+ ret = alloc_chrdev_region(&dev, 0, CROS_MAX_DEV, CROS_EC_DEV_NAME);
+ if (ret < 0) {
+ pr_err(CROS_EC_DEV_NAME ": alloc_chrdev_region() failed\n");
+ goto failed_chrdevreg;
+ }
+ ec_major = MAJOR(dev);
+
+ /* Register the driver */
+ ret = platform_driver_register(&cros_ec_dev_driver);
+ if (ret < 0) {
+ pr_warn(CROS_EC_DEV_NAME ": can't register driver: %d\n", ret);
+ goto failed_devreg;
+ }
+ return 0;
+
+failed_devreg:
+ unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV);
+failed_chrdevreg:
+ class_destroy(cros_class);
+ return ret;
+}
+
+static void __exit cros_ec_dev_exit(void)
+{
+ platform_driver_unregister(&cros_ec_dev_driver);
+ unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
+ class_destroy(cros_class);
+}
+
+module_init(cros_ec_dev_init);
+module_exit(cros_ec_dev_exit);
+
+MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
+MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
+MODULE_VERSION("1.0");
+MODULE_LICENSE("GPL");