/* * ChromeOS EC multi-function device * * Copyright (C) 2012 Google, Inc * * This software is licensed under the terms of the GNU General Public * License version 2, as published by the Free Software Foundation, and * may be copied, distributed, and modified under those terms. * * 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. * * The ChromeOS EC multi function device is used to mux all the requests * to the EC device for its multiple features: keyboard controller, * battery charging and regulator control, firmware update. */ #include <linux/interrupt.h> #include <linux/slab.h> #include <linux/module.h> #include <linux/mfd/core.h> #include <linux/mfd/cros_ec.h> #include <linux/mfd/cros_ec_commands.h> int cros_ec_prepare_tx(struct cros_ec_device *ec_dev, struct cros_ec_msg *msg) { uint8_t *out; int csum, i; BUG_ON(msg->out_len > EC_HOST_PARAM_SIZE); out = ec_dev->dout; out[0] = EC_CMD_VERSION0 + msg->version; out[1] = msg->cmd; out[2] = msg->out_len; csum = out[0] + out[1] + out[2]; for (i = 0; i < msg->out_len; i++) csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->out_buf[i]; out[EC_MSG_TX_HEADER_BYTES + msg->out_len] = (uint8_t)(csum & 0xff); return EC_MSG_TX_PROTO_BYTES + msg->out_len; } EXPORT_SYMBOL(cros_ec_prepare_tx); static int cros_ec_command_sendrecv(struct cros_ec_device *ec_dev, uint16_t cmd, void *out_buf, int out_len, void *in_buf, int in_len) { struct cros_ec_msg msg; msg.version = cmd >> 8; msg.cmd = cmd & 0xff; msg.out_buf = out_buf; msg.out_len = out_len; msg.in_buf = in_buf; msg.in_len = in_len; return ec_dev->command_xfer(ec_dev, &msg); } static int cros_ec_command_recv(struct cros_ec_device *ec_dev, uint16_t cmd, void *buf, int buf_len) { return cros_ec_command_sendrecv(ec_dev, cmd, NULL, 0, buf, buf_len); } static int cros_ec_command_send(struct cros_ec_device *ec_dev, uint16_t cmd, void *buf, int buf_len) { return cros_ec_command_sendrecv(ec_dev, cmd, buf, buf_len, NULL, 0); } static irqreturn_t ec_irq_thread(int irq, void *data) { struct cros_ec_device *ec_dev = data; if (device_may_wakeup(ec_dev->dev)) pm_wakeup_event(ec_dev->dev, 0); blocking_notifier_call_chain(&ec_dev->event_notifier, 1, ec_dev); return IRQ_HANDLED; } static struct mfd_cell cros_devs[] = { { .name = "cros-ec-keyb", .id = 1, .of_compatible = "google,cros-ec-keyb", }, }; int cros_ec_register(struct cros_ec_device *ec_dev) { struct device *dev = ec_dev->dev; int err = 0; BLOCKING_INIT_NOTIFIER_HEAD(&ec_dev->event_notifier); ec_dev->command_send = cros_ec_command_send; ec_dev->command_recv = cros_ec_command_recv; ec_dev->command_sendrecv = cros_ec_command_sendrecv; if (ec_dev->din_size) { ec_dev->din = kmalloc(ec_dev->din_size, GFP_KERNEL); if (!ec_dev->din) { err = -ENOMEM; goto fail_din; } } if (ec_dev->dout_size) { ec_dev->dout = kmalloc(ec_dev->dout_size, GFP_KERNEL); if (!ec_dev->dout) { err = -ENOMEM; goto fail_dout; } } if (!ec_dev->irq) { dev_dbg(dev, "no valid IRQ: %d\n", ec_dev->irq); goto fail_irq; } err = request_threaded_irq(ec_dev->irq, NULL, ec_irq_thread, IRQF_TRIGGER_LOW | IRQF_ONESHOT, "chromeos-ec", ec_dev); if (err) { dev_err(dev, "request irq %d: error %d\n", ec_dev->irq, err); goto fail_irq; } err = mfd_add_devices(dev, 0, cros_devs, ARRAY_SIZE(cros_devs), NULL, ec_dev->irq, NULL); if (err) { dev_err(dev, "failed to add mfd devices\n"); goto fail_mfd; } dev_info(dev, "Chrome EC (%s)\n", ec_dev->name); return 0; fail_mfd: free_irq(ec_dev->irq, ec_dev); fail_irq: kfree(ec_dev->dout); fail_dout: kfree(ec_dev->din); fail_din: return err; } EXPORT_SYMBOL(cros_ec_register); int cros_ec_remove(struct cros_ec_device *ec_dev) { mfd_remove_devices(ec_dev->dev); free_irq(ec_dev->irq, ec_dev); kfree(ec_dev->dout); kfree(ec_dev->din); return 0; } EXPORT_SYMBOL(cros_ec_remove); #ifdef CONFIG_PM_SLEEP int cros_ec_suspend(struct cros_ec_device *ec_dev) { struct device *dev = ec_dev->dev; if (device_may_wakeup(dev)) ec_dev->wake_enabled = !enable_irq_wake(ec_dev->irq); disable_irq(ec_dev->irq); ec_dev->was_wake_device = ec_dev->wake_enabled; return 0; } EXPORT_SYMBOL(cros_ec_suspend); int cros_ec_resume(struct cros_ec_device *ec_dev) { enable_irq(ec_dev->irq); if (ec_dev->wake_enabled) { disable_irq_wake(ec_dev->irq); ec_dev->wake_enabled = 0; } return 0; } EXPORT_SYMBOL(cros_ec_resume); #endif