436 lines
9.9 KiB
C
436 lines
9.9 KiB
C
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/*
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* cros_ec_lightbar - expose the Chromebook Pixel lightbar to userspace
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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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#define pr_fmt(fmt) "cros_ec_lightbar: " fmt
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#include <linux/ctype.h>
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#include <linux/delay.h>
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#include <linux/device.h>
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#include <linux/fs.h>
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#include <linux/kobject.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/module.h>
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#include <linux/platform_device.h>
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#include <linux/sched.h>
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#include <linux/types.h>
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#include <linux/uaccess.h>
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#include <linux/slab.h>
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#include "cros_ec_dev.h"
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/* Rate-limit the lightbar interface to prevent DoS. */
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static unsigned long lb_interval_jiffies = 50 * HZ / 1000;
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static ssize_t interval_msec_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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unsigned long msec = lb_interval_jiffies * 1000 / HZ;
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return scnprintf(buf, PAGE_SIZE, "%lu\n", msec);
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}
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static ssize_t interval_msec_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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unsigned long msec;
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if (kstrtoul(buf, 0, &msec))
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return -EINVAL;
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lb_interval_jiffies = msec * HZ / 1000;
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return count;
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}
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static DEFINE_MUTEX(lb_mutex);
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/* Return 0 if able to throttle correctly, error otherwise */
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static int lb_throttle(void)
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{
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static unsigned long last_access;
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unsigned long now, next_timeslot;
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long delay;
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int ret = 0;
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mutex_lock(&lb_mutex);
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now = jiffies;
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next_timeslot = last_access + lb_interval_jiffies;
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if (time_before(now, next_timeslot)) {
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delay = (long)(next_timeslot) - (long)now;
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set_current_state(TASK_INTERRUPTIBLE);
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if (schedule_timeout(delay) > 0) {
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/* interrupted - just abort */
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ret = -EINTR;
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goto out;
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}
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now = jiffies;
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}
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last_access = now;
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out:
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mutex_unlock(&lb_mutex);
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return ret;
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}
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static struct cros_ec_command *alloc_lightbar_cmd_msg(struct cros_ec_dev *ec)
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{
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struct cros_ec_command *msg;
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int len;
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len = max(sizeof(struct ec_params_lightbar),
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sizeof(struct ec_response_lightbar));
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msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
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if (!msg)
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return NULL;
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msg->version = 0;
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msg->command = EC_CMD_LIGHTBAR_CMD + ec->cmd_offset;
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msg->outsize = sizeof(struct ec_params_lightbar);
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msg->insize = sizeof(struct ec_response_lightbar);
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return msg;
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}
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static int get_lightbar_version(struct cros_ec_dev *ec,
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uint32_t *ver_ptr, uint32_t *flg_ptr)
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{
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struct ec_params_lightbar *param;
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struct ec_response_lightbar *resp;
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struct cros_ec_command *msg;
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int ret;
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msg = alloc_lightbar_cmd_msg(ec);
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if (!msg)
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return 0;
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param = (struct ec_params_lightbar *)msg->data;
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param->cmd = LIGHTBAR_CMD_VERSION;
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ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
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if (ret < 0) {
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ret = 0;
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goto exit;
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}
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switch (msg->result) {
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case EC_RES_INVALID_PARAM:
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/* Pixel had no version command. */
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if (ver_ptr)
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*ver_ptr = 0;
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if (flg_ptr)
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*flg_ptr = 0;
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ret = 1;
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goto exit;
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case EC_RES_SUCCESS:
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resp = (struct ec_response_lightbar *)msg->data;
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/* Future devices w/lightbars should implement this command */
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if (ver_ptr)
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*ver_ptr = resp->version.num;
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if (flg_ptr)
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*flg_ptr = resp->version.flags;
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ret = 1;
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goto exit;
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}
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/* Anything else (ie, EC_RES_INVALID_COMMAND) - no lightbar */
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ret = 0;
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exit:
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kfree(msg);
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return ret;
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}
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static ssize_t version_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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uint32_t version = 0, flags = 0;
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struct cros_ec_dev *ec = container_of(dev,
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struct cros_ec_dev, class_dev);
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int ret;
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ret = lb_throttle();
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if (ret)
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return ret;
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/* This should always succeed, because we check during init. */
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if (!get_lightbar_version(ec, &version, &flags))
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return -EIO;
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return scnprintf(buf, PAGE_SIZE, "%d %d\n", version, flags);
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}
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static ssize_t brightness_store(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct ec_params_lightbar *param;
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struct cros_ec_command *msg;
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int ret;
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unsigned int val;
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struct cros_ec_dev *ec = container_of(dev,
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struct cros_ec_dev, class_dev);
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if (kstrtouint(buf, 0, &val))
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return -EINVAL;
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msg = alloc_lightbar_cmd_msg(ec);
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if (!msg)
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return -ENOMEM;
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param = (struct ec_params_lightbar *)msg->data;
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param->cmd = LIGHTBAR_CMD_SET_BRIGHTNESS;
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param->set_brightness.num = val;
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ret = lb_throttle();
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if (ret)
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goto exit;
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ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
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if (ret < 0)
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goto exit;
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if (msg->result != EC_RES_SUCCESS) {
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ret = -EINVAL;
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goto exit;
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}
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ret = count;
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exit:
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kfree(msg);
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return ret;
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}
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/*
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* We expect numbers, and we'll keep reading until we find them, skipping over
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* any whitespace (sysfs guarantees that the input is null-terminated). Every
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* four numbers are sent to the lightbar as <LED,R,G,B>. We fail at the first
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* parsing error, if we don't parse any numbers, or if we have numbers left
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* over.
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*/
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static ssize_t led_rgb_store(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct ec_params_lightbar *param;
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struct cros_ec_command *msg;
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struct cros_ec_dev *ec = container_of(dev,
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struct cros_ec_dev, class_dev);
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unsigned int val[4];
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int ret, i = 0, j = 0, ok = 0;
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msg = alloc_lightbar_cmd_msg(ec);
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if (!msg)
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return -ENOMEM;
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do {
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/* Skip any whitespace */
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while (*buf && isspace(*buf))
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buf++;
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if (!*buf)
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break;
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ret = sscanf(buf, "%i", &val[i++]);
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if (ret == 0)
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goto exit;
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if (i == 4) {
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param = (struct ec_params_lightbar *)msg->data;
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param->cmd = LIGHTBAR_CMD_SET_RGB;
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param->set_rgb.led = val[0];
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param->set_rgb.red = val[1];
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param->set_rgb.green = val[2];
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param->set_rgb.blue = val[3];
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/*
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* Throttle only the first of every four transactions,
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* so that the user can update all four LEDs at once.
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*/
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if ((j++ % 4) == 0) {
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ret = lb_throttle();
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if (ret)
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goto exit;
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}
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ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
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if (ret < 0)
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goto exit;
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if (msg->result != EC_RES_SUCCESS)
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goto exit;
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i = 0;
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ok = 1;
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}
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/* Skip over the number we just read */
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while (*buf && !isspace(*buf))
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buf++;
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} while (*buf);
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exit:
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kfree(msg);
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return (ok && i == 0) ? count : -EINVAL;
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}
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static char const *seqname[] = {
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"ERROR", "S5", "S3", "S0", "S5S3", "S3S0",
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"S0S3", "S3S5", "STOP", "RUN", "PULSE", "TEST", "KONAMI",
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};
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static ssize_t sequence_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct ec_params_lightbar *param;
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struct ec_response_lightbar *resp;
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struct cros_ec_command *msg;
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int ret;
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struct cros_ec_dev *ec = container_of(dev,
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struct cros_ec_dev, class_dev);
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msg = alloc_lightbar_cmd_msg(ec);
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if (!msg)
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return -ENOMEM;
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param = (struct ec_params_lightbar *)msg->data;
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param->cmd = LIGHTBAR_CMD_GET_SEQ;
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ret = lb_throttle();
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if (ret)
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goto exit;
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ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
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if (ret < 0)
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goto exit;
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if (msg->result != EC_RES_SUCCESS) {
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ret = scnprintf(buf, PAGE_SIZE,
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"ERROR: EC returned %d\n", msg->result);
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goto exit;
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}
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resp = (struct ec_response_lightbar *)msg->data;
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if (resp->get_seq.num >= ARRAY_SIZE(seqname))
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ret = scnprintf(buf, PAGE_SIZE, "%d\n", resp->get_seq.num);
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else
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ret = scnprintf(buf, PAGE_SIZE, "%s\n",
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seqname[resp->get_seq.num]);
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exit:
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kfree(msg);
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return ret;
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}
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static ssize_t sequence_store(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct ec_params_lightbar *param;
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struct cros_ec_command *msg;
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unsigned int num;
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int ret, len;
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struct cros_ec_dev *ec = container_of(dev,
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struct cros_ec_dev, class_dev);
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for (len = 0; len < count; len++)
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if (!isalnum(buf[len]))
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break;
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for (num = 0; num < ARRAY_SIZE(seqname); num++)
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if (!strncasecmp(seqname[num], buf, len))
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break;
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if (num >= ARRAY_SIZE(seqname)) {
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ret = kstrtouint(buf, 0, &num);
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if (ret)
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return ret;
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}
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msg = alloc_lightbar_cmd_msg(ec);
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if (!msg)
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return -ENOMEM;
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param = (struct ec_params_lightbar *)msg->data;
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param->cmd = LIGHTBAR_CMD_SEQ;
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param->seq.num = num;
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ret = lb_throttle();
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if (ret)
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goto exit;
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ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
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if (ret < 0)
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goto exit;
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if (msg->result != EC_RES_SUCCESS) {
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ret = -EINVAL;
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goto exit;
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}
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ret = count;
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exit:
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kfree(msg);
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return ret;
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}
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/* Module initialization */
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static DEVICE_ATTR_RW(interval_msec);
|
||
|
|
static DEVICE_ATTR_RO(version);
|
||
|
|
static DEVICE_ATTR_WO(brightness);
|
||
|
|
static DEVICE_ATTR_WO(led_rgb);
|
||
|
|
static DEVICE_ATTR_RW(sequence);
|
||
|
|
static struct attribute *__lb_cmds_attrs[] = {
|
||
|
|
&dev_attr_interval_msec.attr,
|
||
|
|
&dev_attr_version.attr,
|
||
|
|
&dev_attr_brightness.attr,
|
||
|
|
&dev_attr_led_rgb.attr,
|
||
|
|
&dev_attr_sequence.attr,
|
||
|
|
NULL,
|
||
|
|
};
|
||
|
|
|
||
|
|
static umode_t cros_ec_lightbar_attrs_are_visible(struct kobject *kobj,
|
||
|
|
struct attribute *a, int n)
|
||
|
|
{
|
||
|
|
struct device *dev = container_of(kobj, struct device, kobj);
|
||
|
|
struct cros_ec_dev *ec = container_of(dev,
|
||
|
|
struct cros_ec_dev, class_dev);
|
||
|
|
struct platform_device *pdev = to_platform_device(ec->dev);
|
||
|
|
struct cros_ec_platform *pdata = pdev->dev.platform_data;
|
||
|
|
int is_cros_ec;
|
||
|
|
|
||
|
|
is_cros_ec = strcmp(pdata->ec_name, CROS_EC_DEV_NAME);
|
||
|
|
|
||
|
|
if (is_cros_ec != 0)
|
||
|
|
return 0;
|
||
|
|
|
||
|
|
/* Only instantiate this stuff if the EC has a lightbar */
|
||
|
|
if (get_lightbar_version(ec, NULL, NULL))
|
||
|
|
return a->mode;
|
||
|
|
else
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
struct attribute_group cros_ec_lightbar_attr_group = {
|
||
|
|
.name = "lightbar",
|
||
|
|
.attrs = __lb_cmds_attrs,
|
||
|
|
.is_visible = cros_ec_lightbar_attrs_are_visible,
|
||
|
|
};
|