diff options
Diffstat (limited to 'drivers/mfd/cros_ec.c')
| -rw-r--r-- | drivers/mfd/cros_ec.c | 196 |
1 files changed, 196 insertions, 0 deletions
diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c new file mode 100644 index 00000000000..10cd14e35eb --- /dev/null +++ b/drivers/mfd/cros_ec.c @@ -0,0 +1,196 @@ +/* + * 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 |