diff options
Diffstat (limited to 'drivers/mfd/cros_ec_dev.c')
| -rw-r--r-- | drivers/mfd/cros_ec_dev.c | 552 |
1 files changed, 552 insertions, 0 deletions
diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c new file mode 100644 index 000000000000..e4fafdd96e5e --- /dev/null +++ b/drivers/mfd/cros_ec_dev.c @@ -0,0 +1,552 @@ +/* + * 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/mfd/core.h> +#include <linux/module.h> +#include <linux/platform_device.h> +#include <linux/pm.h> +#include <linux/slab.h> +#include <linux/uaccess.h> + +#include "cros_ec_dev.h" + +#define DRV_NAME "cros-ec-dev" + +/* Device variables */ +#define CROS_MAX_DEV 128 +static int ec_major; + +static const struct attribute_group *cros_ec_groups[] = { + &cros_ec_attr_group, + &cros_ec_lightbar_attr_group, + &cros_ec_vbc_attr_group, + NULL, +}; + +static struct class cros_class = { + .owner = THIS_MODULE, + .name = "chromeos", + .dev_groups = cros_ec_groups, +}; + +/* Basic communication */ +static int ec_get_version(struct cros_ec_dev *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; + int ret; + + msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL); + if (!msg) + return -ENOMEM; + + msg->version = 0; + msg->command = EC_CMD_GET_VERSION + ec->cmd_offset; + msg->insize = sizeof(*resp); + msg->outsize = 0; + + ret = cros_ec_cmd_xfer(ec->ec_dev, msg); + if (ret < 0) + goto exit; + + if (msg->result != EC_RES_SUCCESS) { + snprintf(str, maxlen, + "%s\nUnknown EC version: EC returned %d\n", + CROS_EC_DEV_VERSION, msg->result); + ret = -EINVAL; + goto exit; + } + + resp = (struct ec_response_get_version *)msg->data; + 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]); + + ret = 0; +exit: + kfree(msg); + return ret; +} + +static int cros_ec_check_features(struct cros_ec_dev *ec, int feature) +{ + struct cros_ec_command *msg; + int ret; + + if (ec->features[0] == -1U && ec->features[1] == -1U) { + /* features bitmap not read yet */ + + msg = kmalloc(sizeof(*msg) + sizeof(ec->features), GFP_KERNEL); + if (!msg) + return -ENOMEM; + + msg->version = 0; + msg->command = EC_CMD_GET_FEATURES + ec->cmd_offset; + msg->insize = sizeof(ec->features); + msg->outsize = 0; + + ret = cros_ec_cmd_xfer(ec->ec_dev, msg); + if (ret < 0 || msg->result != EC_RES_SUCCESS) { + dev_warn(ec->dev, "cannot get EC features: %d/%d\n", + ret, msg->result); + memset(ec->features, 0, sizeof(ec->features)); + } + + memcpy(ec->features, msg->data, sizeof(ec->features)); + + dev_dbg(ec->dev, "EC features %08x %08x\n", + ec->features[0], ec->features[1]); + + kfree(msg); + } + + return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature); +} + +/* Device file ops */ +static int ec_device_open(struct inode *inode, struct file *filp) +{ + struct cros_ec_dev *ec = container_of(inode->i_cdev, + struct cros_ec_dev, cdev); + filp->private_data = ec; + nonseekable_open(inode, filp); + 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_dev *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_dev *ec, void __user *arg) +{ + long ret; + struct cros_ec_command u_cmd; + struct cros_ec_command *s_cmd; + + if (copy_from_user(&u_cmd, arg, sizeof(u_cmd))) + return -EFAULT; + + if ((u_cmd.outsize > EC_MAX_MSG_BYTES) || + (u_cmd.insize > EC_MAX_MSG_BYTES)) + return -EINVAL; + + s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize), + GFP_KERNEL); + if (!s_cmd) + return -ENOMEM; + + if (copy_from_user(s_cmd, arg, sizeof(*s_cmd) + u_cmd.outsize)) { + ret = -EFAULT; + goto exit; + } + + if (u_cmd.outsize != s_cmd->outsize || + u_cmd.insize != s_cmd->insize) { + ret = -EINVAL; + goto exit; + } + + s_cmd->command += ec->cmd_offset; + ret = cros_ec_cmd_xfer(ec->ec_dev, s_cmd); + /* Only copy data to userland if data was received. */ + if (ret < 0) + goto exit; + + if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + s_cmd->insize)) + ret = -EFAULT; +exit: + kfree(s_cmd); + return ret; +} + +static long ec_device_ioctl_readmem(struct cros_ec_dev *ec, void __user *arg) +{ + struct cros_ec_device *ec_dev = ec->ec_dev; + struct cros_ec_readmem s_mem = { }; + long num; + + /* Not every platform supports direct reads */ + if (!ec_dev->cmd_readmem) + return -ENOTTY; + + if (copy_from_user(&s_mem, arg, sizeof(s_mem))) + return -EFAULT; + + num = ec_dev->cmd_readmem(ec_dev, 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_dev *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, +#ifdef CONFIG_COMPAT + .compat_ioctl = ec_device_ioctl, +#endif +}; + +static void __remove(struct device *dev) +{ + struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev, + class_dev); + kfree(ec); +} + +static void cros_ec_sensors_register(struct cros_ec_dev *ec) +{ + /* + * Issue a command to get the number of sensor reported. + * Build an array of sensors driver and register them all. + */ + int ret, i, id, sensor_num; + struct mfd_cell *sensor_cells; + struct cros_ec_sensor_platform *sensor_platforms; + int sensor_type[MOTIONSENSE_TYPE_MAX]; + struct ec_params_motion_sense *params; + struct ec_response_motion_sense *resp; + struct cros_ec_command *msg; + + msg = kzalloc(sizeof(struct cros_ec_command) + + max(sizeof(*params), sizeof(*resp)), GFP_KERNEL); + if (msg == NULL) + return; + + msg->version = 2; + msg->command = EC_CMD_MOTION_SENSE_CMD + ec->cmd_offset; + msg->outsize = sizeof(*params); + msg->insize = sizeof(*resp); + + params = (struct ec_params_motion_sense *)msg->data; + params->cmd = MOTIONSENSE_CMD_DUMP; + + ret = cros_ec_cmd_xfer(ec->ec_dev, msg); + if (ret < 0 || msg->result != EC_RES_SUCCESS) { + dev_warn(ec->dev, "cannot get EC sensor information: %d/%d\n", + ret, msg->result); + goto error; + } + + resp = (struct ec_response_motion_sense *)msg->data; + sensor_num = resp->dump.sensor_count; + /* Allocate 2 extra sensors in case lid angle or FIFO are needed */ + sensor_cells = kzalloc(sizeof(struct mfd_cell) * (sensor_num + 2), + GFP_KERNEL); + if (sensor_cells == NULL) + goto error; + + sensor_platforms = kzalloc(sizeof(struct cros_ec_sensor_platform) * + (sensor_num + 1), GFP_KERNEL); + if (sensor_platforms == NULL) + goto error_platforms; + + memset(sensor_type, 0, sizeof(sensor_type)); + id = 0; + for (i = 0; i < sensor_num; i++) { + params->cmd = MOTIONSENSE_CMD_INFO; + params->info.sensor_num = i; + ret = cros_ec_cmd_xfer(ec->ec_dev, msg); + if (ret < 0 || msg->result != EC_RES_SUCCESS) { + dev_warn(ec->dev, "no info for EC sensor %d : %d/%d\n", + i, ret, msg->result); + continue; + } + switch (resp->info.type) { + case MOTIONSENSE_TYPE_ACCEL: + sensor_cells[id].name = "cros-ec-accel"; + break; + case MOTIONSENSE_TYPE_BARO: + sensor_cells[id].name = "cros-ec-baro"; + break; + case MOTIONSENSE_TYPE_GYRO: + sensor_cells[id].name = "cros-ec-gyro"; + break; + case MOTIONSENSE_TYPE_MAG: + sensor_cells[id].name = "cros-ec-mag"; + break; + case MOTIONSENSE_TYPE_PROX: + sensor_cells[id].name = "cros-ec-prox"; + break; + case MOTIONSENSE_TYPE_LIGHT: + sensor_cells[id].name = "cros-ec-light"; + break; + case MOTIONSENSE_TYPE_ACTIVITY: + sensor_cells[id].name = "cros-ec-activity"; + break; + default: + dev_warn(ec->dev, "unknown type %d\n", resp->info.type); + continue; + } + sensor_platforms[id].sensor_num = i; + sensor_cells[id].id = sensor_type[resp->info.type]; + sensor_cells[id].platform_data = &sensor_platforms[id]; + sensor_cells[id].pdata_size = + sizeof(struct cros_ec_sensor_platform); + + sensor_type[resp->info.type]++; + id++; + } + if (sensor_type[MOTIONSENSE_TYPE_ACCEL] >= 2) { + sensor_platforms[id].sensor_num = sensor_num; + + sensor_cells[id].name = "cros-ec-angle"; + sensor_cells[id].id = 0; + sensor_cells[id].platform_data = &sensor_platforms[id]; + sensor_cells[id].pdata_size = + sizeof(struct cros_ec_sensor_platform); + id++; + } + if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE_FIFO)) { + sensor_cells[id].name = "cros-ec-ring"; + id++; + } + + ret = mfd_add_devices(ec->dev, 0, sensor_cells, id, + NULL, 0, NULL); + if (ret) + dev_err(ec->dev, "failed to add EC sensors\n"); + + kfree(sensor_platforms); +error_platforms: + kfree(sensor_cells); +error: + kfree(msg); +} + +static int ec_device_probe(struct platform_device *pdev) +{ + int retval = -ENOMEM; + struct device *dev = &pdev->dev; + struct cros_ec_platform *ec_platform = dev_get_platdata(dev); + struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL); + + if (!ec) + return retval; + + dev_set_drvdata(dev, ec); + ec->ec_dev = dev_get_drvdata(dev->parent); + ec->dev = dev; + ec->cmd_offset = ec_platform->cmd_offset; + ec->features[0] = -1U; /* Not cached yet */ + ec->features[1] = -1U; /* Not cached yet */ + device_initialize(&ec->class_dev); + cdev_init(&ec->cdev, &fops); + + /* + * Add the class device + * Link to the character device for creating the /dev entry + * in devtmpfs. + */ + ec->class_dev.devt = MKDEV(ec_major, pdev->id); + ec->class_dev.class = &cros_class; + ec->class_dev.parent = dev; + ec->class_dev.release = __remove; + + retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name); + if (retval) { + dev_err(dev, "dev_set_name failed => %d\n", retval); + goto failed; + } + + retval = cdev_device_add(&ec->cdev, &ec->class_dev); + if (retval) { + dev_err(dev, "cdev_device_add failed => %d\n", retval); + goto failed; + } + + if (cros_ec_debugfs_init(ec)) + dev_warn(dev, "failed to create debugfs directory\n"); + + /* check whether this EC is a sensor hub. */ + if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE)) + cros_ec_sensors_register(ec); + + /* Take control of the lightbar from the EC. */ + lb_manual_suspend_ctrl(ec, 1); + + return 0; + +failed: + put_device(&ec->class_dev); + return retval; +} + +static int ec_device_remove(struct platform_device *pdev) +{ + struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev); + + /* Let the EC take over the lightbar again. */ + lb_manual_suspend_ctrl(ec, 0); + + cros_ec_debugfs_remove(ec); + + cdev_del(&ec->cdev); + device_unregister(&ec->class_dev); + return 0; +} + +static const struct platform_device_id cros_ec_id[] = { + { DRV_NAME, 0 }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(platform, cros_ec_id); + +static __maybe_unused int ec_device_suspend(struct device *dev) +{ + struct cros_ec_dev *ec = dev_get_drvdata(dev); + + lb_suspend(ec); + + return 0; +} + +static __maybe_unused int ec_device_resume(struct device *dev) +{ + struct cros_ec_dev *ec = dev_get_drvdata(dev); + + lb_resume(ec); + + return 0; +} + +static const struct dev_pm_ops cros_ec_dev_pm_ops = { +#ifdef CONFIG_PM_SLEEP + .suspend = ec_device_suspend, + .resume = ec_device_resume, +#endif +}; + +static struct platform_driver cros_ec_dev_driver = { + .driver = { + .name = DRV_NAME, + .pm = &cros_ec_dev_pm_ops, + }, + .probe = ec_device_probe, + .remove = ec_device_remove, +}; + +static int __init cros_ec_dev_init(void) +{ + int ret; + dev_t dev = 0; + + ret = class_register(&cros_class); + if (ret) { + pr_err(CROS_EC_DEV_NAME ": failed to register device class\n"); + return ret; + } + + /* 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_unregister(&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_unregister(&cros_class); +} + +module_init(cros_ec_dev_init); +module_exit(cros_ec_dev_exit); + +MODULE_ALIAS("platform:" DRV_NAME); +MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>"); +MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller"); +MODULE_VERSION("1.0"); +MODULE_LICENSE("GPL"); |