diff options
| -rw-r--r-- | Documentation/devicetree/bindings/mfd/cros-ec.txt | 56 | ||||
| -rw-r--r-- | drivers/mfd/Kconfig | 8 | ||||
| -rw-r--r-- | drivers/mfd/Makefile | 1 | ||||
| -rw-r--r-- | drivers/mfd/cros_ec.c | 189 | ||||
| -rw-r--r-- | include/linux/mfd/cros_ec.h | 170 |
5 files changed, 424 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mfd/cros-ec.txt b/Documentation/devicetree/bindings/mfd/cros-ec.txt new file mode 100644 index 000000000000..e0e59c58a1f9 --- /dev/null +++ b/Documentation/devicetree/bindings/mfd/cros-ec.txt @@ -0,0 +1,56 @@ +ChromeOS Embedded Controller + +Google's ChromeOS EC is a Cortex-M device which talks to the AP and +implements various function such as keyboard and battery charging. + +The EC can be connect through various means (I2C, SPI, LPC) and the +compatible string used depends on the inteface. Each connection method has +its own driver which connects to the top level interface-agnostic EC driver. +Other Linux driver (such as cros-ec-keyb for the matrix keyboard) connect to +the top-level driver. + +Required properties (I2C): +- compatible: "google,cros-ec-i2c" +- reg: I2C slave address + +Required properties (SPI): +- compatible: "google,cros-ec-spi" +- reg: SPI chip select + +Required properties (LPC): +- compatible: "google,cros-ec-lpc" +- reg: List of (IO address, size) pairs defining the interface uses + + +Example for I2C: + +i2c@12CA0000 { + cros-ec@1e { + reg = <0x1e>; + compatible = "google,cros-ec-i2c"; + interrupts = <14 0>; + interrupt-parent = <&wakeup_eint>; + wakeup-source; + }; + + +Example for SPI: + +spi@131b0000 { + ec@0 { + compatible = "google,cros-ec-spi"; + reg = <0x0>; + interrupts = <14 0>; + interrupt-parent = <&wakeup_eint>; + wakeup-source; + spi-max-frequency = <5000000>; + controller-data { + cs-gpio = <&gpf0 3 4 3 0>; + samsung,spi-cs; + samsung,spi-feedback-delay = <2>; + }; + }; +}; + + +Example for LPC is not supplied as it is not yet implemented. diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig index c346941a2515..a8bafb560196 100644 --- a/drivers/mfd/Kconfig +++ b/drivers/mfd/Kconfig @@ -21,6 +21,14 @@ config MFD_88PM860X select individual components like voltage regulators, RTC and battery-charger under the corresponding menus. +config MFD_CROS_EC + tristate "Support ChromeOS Embedded Controller" + help + If you say Y here you get support for the ChromeOS Embedded + Controller (EC) providing keyboard, battery and power services. + You also ned to enable the driver for the bus you are using. The + protocol for talking to the EC is defined by the bus driver. + config MFD_88PM800 tristate "Support Marvell 88PM800" depends on I2C=y && GENERIC_HARDIRQS diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile index b90409c23664..967767d3d759 100644 --- a/drivers/mfd/Makefile +++ b/drivers/mfd/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_MFD_88PM800) += 88pm800.o 88pm80x.o obj-$(CONFIG_MFD_88PM805) += 88pm805.o 88pm80x.o obj-$(CONFIG_MFD_SM501) += sm501.o obj-$(CONFIG_MFD_ASIC3) += asic3.o tmio_core.o +obj-$(CONFIG_MFD_CROS_EC) += cros_ec.o rtsx_pci-objs := rtsx_pcr.o rts5209.o rts5229.o rtl8411.o rts5227.o obj-$(CONFIG_MFD_RTSX_PCI) += rtsx_pci.o diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c new file mode 100644 index 000000000000..ac824ccab52a --- /dev/null +++ b/drivers/mfd/cros_ec.c @@ -0,0 +1,189 @@ +/* + * 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/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; +} + +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; +} + +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; +} + +#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; +} + +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; +} +#endif diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h new file mode 100644 index 000000000000..032af7fc5b2e --- /dev/null +++ b/include/linux/mfd/cros_ec.h @@ -0,0 +1,170 @@ +/* + * 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. + */ + +#ifndef __LINUX_MFD_CROS_EC_H +#define __LINUX_MFD_CROS_EC_H + +#include <linux/mfd/cros_ec_commands.h> + +/* + * Command interface between EC and AP, for LPC, I2C and SPI interfaces. + */ +enum { + EC_MSG_TX_HEADER_BYTES = 3, + EC_MSG_TX_TRAILER_BYTES = 1, + EC_MSG_TX_PROTO_BYTES = EC_MSG_TX_HEADER_BYTES + + EC_MSG_TX_TRAILER_BYTES, + EC_MSG_RX_PROTO_BYTES = 3, + + /* Max length of messages */ + EC_MSG_BYTES = EC_HOST_PARAM_SIZE + EC_MSG_TX_PROTO_BYTES, + +}; + +/** + * struct cros_ec_msg - A message sent to the EC, and its reply + * + * @version: Command version number (often 0) + * @cmd: Command to send (EC_CMD_...) + * @out_buf: Outgoing payload (to EC) + * @outlen: Outgoing length + * @in_buf: Incoming payload (from EC) + * @in_len: Incoming length + */ +struct cros_ec_msg { + u8 version; + u8 cmd; + uint8_t *out_buf; + int out_len; + uint8_t *in_buf; + int in_len; +}; + +/** + * struct cros_ec_device - Information about a ChromeOS EC device + * + * @name: Name of this EC interface + * @priv: Private data + * @irq: Interrupt to use + * @din: input buffer (from EC) + * @dout: output buffer (to EC) + * \note + * These two buffers will always be dword-aligned and include enough + * space for up to 7 word-alignment bytes also, so we can ensure that + * the body of the message is always dword-aligned (64-bit). + * + * We use this alignment to keep ARM and x86 happy. Probably word + * alignment would be OK, there might be a small performance advantage + * to using dword. + * @din_size: size of din buffer + * @dout_size: size of dout buffer + * @command_send: send a command + * @command_recv: receive a command + * @ec_name: name of EC device (e.g. 'chromeos-ec') + * @phys_name: name of physical comms layer (e.g. 'i2c-4') + * @parent: pointer to parent device (e.g. i2c or spi device) + * @dev: Device pointer + * dev_lock: Lock to prevent concurrent access + * @wake_enabled: true if this device can wake the system from sleep + * @was_wake_device: true if this device was set to wake the system from + * sleep at the last suspend + * @event_notifier: interrupt event notifier for transport devices + */ +struct cros_ec_device { + const char *name; + void *priv; + int irq; + uint8_t *din; + uint8_t *dout; + int din_size; + int dout_size; + int (*command_send)(struct cros_ec_device *ec, + uint16_t cmd, void *out_buf, int out_len); + int (*command_recv)(struct cros_ec_device *ec, + uint16_t cmd, void *in_buf, int in_len); + int (*command_sendrecv)(struct cros_ec_device *ec, + uint16_t cmd, void *out_buf, int out_len, + void *in_buf, int in_len); + int (*command_xfer)(struct cros_ec_device *ec, + struct cros_ec_msg *msg); + + const char *ec_name; + const char *phys_name; + struct device *parent; + + /* These are --private-- fields - do not assign */ + struct device *dev; + struct mutex dev_lock; + bool wake_enabled; + bool was_wake_device; + struct blocking_notifier_head event_notifier; +}; + +/** + * cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device + * + * This can be called by drivers to handle a suspend event. + * + * ec_dev: Device to suspend + * @return 0 if ok, -ve on error + */ +int cros_ec_suspend(struct cros_ec_device *ec_dev); + +/** + * cros_ec_resume - Handle a resume operation for the ChromeOS EC device + * + * This can be called by drivers to handle a resume event. + * + * @ec_dev: Device to resume + * @return 0 if ok, -ve on error + */ +int cros_ec_resume(struct cros_ec_device *ec_dev); + +/** + * cros_ec_prepare_tx - Prepare an outgoing message in the output buffer + * + * This is intended to be used by all ChromeOS EC drivers, but at present + * only SPI uses it. Once LPC uses the same protocol it can start using it. + * I2C could use it now, with a refactor of the existing code. + * + * @ec_dev: Device to register + * @msg: Message to write + */ +int cros_ec_prepare_tx(struct cros_ec_device *ec_dev, + struct cros_ec_msg *msg); + +/** + * cros_ec_remove - Remove a ChromeOS EC + * + * Call this to deregister a ChromeOS EC. After this you should call + * cros_ec_free(). + * + * @ec_dev: Device to register + * @return 0 if ok, -ve on error + */ +int cros_ec_remove(struct cros_ec_device *ec_dev); + +/** + * cros_ec_register - Register a new ChromeOS EC, using the provided info + * + * Before calling this, allocate a pointer to a new device and then fill + * in all the fields up to the --private-- marker. + * + * @ec_dev: Device to register + * @return 0 if ok, -ve on error + */ +int cros_ec_register(struct cros_ec_device *ec_dev); + +#endif /* __LINUX_MFD_CROS_EC_H */ |