Merge tag 'chrome-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/olof/chrome-platform

Pull chrome platform updates from Olof Johansson:
 "Here's a set of updates to the Chrome OS platform drivers for this
  merge window.

  Main new things this cycle is:

   - Driver changes to expose the lightbar to users.  With this, you can
     make your own blinkenlights on Chromebook Pixels.

   - Changes in the way that the atmel_mxt trackpads are probed.  The
     laptop driver is trying to be smart and not instantiate the devices
     that don't answer to probe.  For the trackpad that can come up in
     two modes (bootloader or regular), this gets complicated since the
     driver already knows how to handle the two modes including the
     actual addresses used.  So now the laptop driver needs to know more
     too, instantiating the regular address even if the bootloader one
     is the probe that passed.

   - mfd driver improvements by Javier Martines Canillas, and a few
     bugfixes from him, kbuild and myself"

* tag 'chrome-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/olof/chrome-platform:
  platform/chrome: chromeos_laptop - instantiate Atmel at primary address
  platform/chrome: cros_ec_lpc - Depend on X86 || COMPILE_TEST
  platform/chrome: cros_ec_lpc - Include linux/io.h header file
  platform/chrome: fix platform_no_drv_owner.cocci warnings
  platform/chrome: cros_ec_lightbar - fix duplicate const warning
  platform/chrome: cros_ec_dev - fix Unknown escape '%' warning
  platform/chrome: Expose Chrome OS Lightbar to users
  platform/chrome: Create sysfs attributes for the ChromeOS EC
  mfd: cros_ec: Instantiate ChromeOS EC character device
  platform/chrome: Add Chrome OS EC userspace device interface
  platform/chrome: Add cros_ec_lpc driver for x86 devices
  mfd: cros_ec: Add char dev and virtual dev pointers
  mfd: cros_ec: Use fixed size arrays to transfer data with the EC

Documentation/ioctl/ioctl-number.txt

@@ -321,6 +321,7 @@ Code  Seq#(hex)	Include File		Comments
 0xDB	00-0F	drivers/char/mwave/mwavepub.h
 0xDD	00-3F	ZFCP device driver	see drivers/s390/scsi/
 					<mailto:aherrman@de.ibm.com>
+0xEC	00-01	drivers/platform/chrome/cros_ec_dev.h	ChromeOS EC driver
 0xF3	00-3F	drivers/usb/misc/sisusbvga/sisusb.h	sisfb (in development)
 					<mailto:thomas@winischhofer.net>
 0xF4	00-1F	video/mbxfb.h		mbxfb

drivers/i2c/busses/i2c-cros-ec-tunnel.c

@@ -182,72 +182,41 @@ static int ec_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg i2c_msgs[],
 	const u16 bus_num = bus->remote_bus;
 	int request_len;
 	int response_len;
-	u8 *request = NULL;
-	u8 *response = NULL;
 	int result;
-	struct cros_ec_command msg;
+	struct cros_ec_command msg = { };
 
 	request_len = ec_i2c_count_message(i2c_msgs, num);
 	if (request_len < 0) {
 		dev_warn(dev, "Error constructing message %d\n", request_len);
-		result = request_len;
-		goto exit;
+		return request_len;
 	}
+
 	response_len = ec_i2c_count_response(i2c_msgs, num);
 	if (response_len < 0) {
 		/* Unexpected; no errors should come when NULL response */
 		dev_warn(dev, "Error preparing response %d\n", response_len);
-		result = response_len;
-		goto exit;
-	}
-
-	if (request_len <= ARRAY_SIZE(bus->request_buf)) {
-		request = bus->request_buf;
-	} else {
-		request = kzalloc(request_len, GFP_KERNEL);
-		if (request == NULL) {
-			result = -ENOMEM;
-			goto exit;
-		}
-	}
-	if (response_len <= ARRAY_SIZE(bus->response_buf)) {
-		response = bus->response_buf;
-	} else {
-		response = kzalloc(response_len, GFP_KERNEL);
-		if (response == NULL) {
-			result = -ENOMEM;
-			goto exit;
-		}
+		return response_len;
 	}
 
-	result = ec_i2c_construct_message(request, i2c_msgs, num, bus_num);
+	result = ec_i2c_construct_message(msg.outdata, i2c_msgs, num, bus_num);
 	if (result)
-		goto exit;
+		return result;
 
 	msg.version = 0;
 	msg.command = EC_CMD_I2C_PASSTHRU;
-	msg.outdata = request;
 	msg.outsize = request_len;
-	msg.indata = response;
 	msg.insize = response_len;
 
 	result = cros_ec_cmd_xfer(bus->ec, &msg);
 	if (result < 0)
-		goto exit;
+		return result;
 
-	result = ec_i2c_parse_response(response, i2c_msgs, &num);
+	result = ec_i2c_parse_response(msg.indata, i2c_msgs, &num);
 	if (result < 0)
-		goto exit;
+		return result;
 
 	/* Indicate success by saying how many messages were sent */
-	result = num;
-exit:
-	if (request != bus->request_buf)
-		kfree(request);
-	if (response != bus->response_buf)
-		kfree(response);
-
-	return result;
+	return num;
 }
 
 static u32 ec_i2c_functionality(struct i2c_adapter *adap)

drivers/input/keyboard/cros_ec_keyb.c

@@ -148,16 +148,19 @@ static void cros_ec_keyb_process(struct cros_ec_keyb *ckdev,
 
 static int cros_ec_keyb_get_state(struct cros_ec_keyb *ckdev, uint8_t *kb_state)
 {
+	int ret;
 	struct cros_ec_command msg = {
-		.version = 0,
 		.command = EC_CMD_MKBP_STATE,
-		.outdata = NULL,
-		.outsize = 0,
-		.indata = kb_state,
 		.insize = ckdev->cols,
 	};
 
-	return cros_ec_cmd_xfer(ckdev->ec, &msg);
+	ret = cros_ec_cmd_xfer(ckdev->ec, &msg);
+	if (ret < 0)
+		return ret;
+
+	memcpy(kb_state, msg.indata, ckdev->cols);
+
+	return 0;
 }
 
 static irqreturn_t cros_ec_keyb_irq(int irq, void *data)

drivers/mfd/cros_ec.c

@@ -74,15 +74,11 @@ int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
 	ret = ec_dev->cmd_xfer(ec_dev, msg);
 	if (msg->result == EC_RES_IN_PROGRESS) {
 		int i;
-		struct cros_ec_command status_msg;
-		struct ec_response_get_comms_status status;
+		struct cros_ec_command status_msg = { };
+		struct ec_response_get_comms_status *status;
 
-		status_msg.version = 0;
 		status_msg.command = EC_CMD_GET_COMMS_STATUS;
-		status_msg.outdata = NULL;
-		status_msg.outsize = 0;
-		status_msg.indata = (uint8_t *)&status;
-		status_msg.insize = sizeof(status);
+		status_msg.insize = sizeof(*status);
 
 		/*
 		 * Query the EC's status until it's no longer busy or
@@ -98,7 +94,10 @@ int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
 			msg->result = status_msg.result;
 			if (status_msg.result != EC_RES_SUCCESS)
 				break;
-			if (!(status.flags & EC_COMMS_STATUS_PROCESSING))
+
+			status = (struct ec_response_get_comms_status *)
+				 status_msg.indata;
+			if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
 				break;
 		}
 	}
@@ -119,6 +118,10 @@ static const struct mfd_cell cros_devs[] = {
 		.id = 2,
 		.of_compatible = "google,cros-ec-i2c-tunnel",
 	},
+	{
+		.name = "cros-ec-ctl",
+		.id = 3,
+	},
 };
 
 int cros_ec_register(struct cros_ec_device *ec_dev)

drivers/platform/chrome/Kconfig

@@ -4,7 +4,7 @@
 
 menuconfig CHROME_PLATFORMS
 	bool "Platform support for Chrome hardware"
-	depends on X86
+	depends on X86 || ARM
 	---help---
 	  Say Y here to get to see options for platform support for
 	  various Chromebooks and Chromeboxes. This option alone does
@@ -16,8 +16,7 @@ if CHROME_PLATFORMS
 
 config CHROMEOS_LAPTOP
 	tristate "Chrome OS Laptop"
-	depends on I2C
-	depends on DMI
+	depends on I2C && DMI && X86
 	---help---
 	  This driver instantiates i2c and smbus devices such as
 	  light sensors and touchpads.
@@ -27,6 +26,7 @@ config CHROMEOS_LAPTOP
 
 config CHROMEOS_PSTORE
 	tristate "Chrome OS pstore support"
+	depends on X86
 	---help---
 	  This module instantiates the persistent storage on x86 ChromeOS
 	  devices. It can be used to store away console logs and crash
@@ -38,5 +38,25 @@ config CHROMEOS_PSTORE
 	  If you have a supported Chromebook, choose Y or M here.
 	  The module will be called chromeos_pstore.
 
+config CROS_EC_CHARDEV
+        tristate "Chrome OS Embedded Controller userspace device interface"
+        depends on MFD_CROS_EC
+        ---help---
+          This driver adds support to talk with the ChromeOS EC from userspace.
+
+          If you have a supported Chromebook, choose Y or M here.
+          The module will be called cros_ec_dev.
+
+config CROS_EC_LPC
+        tristate "ChromeOS Embedded Controller (LPC)"
+        depends on MFD_CROS_EC && (X86 || COMPILE_TEST)
+        help
+          If you say Y here, you get support for talking to the ChromeOS EC
+          over an LPC bus. This uses a simple byte-level protocol with a
+          checksum. This is used for userspace access only. The kernel
+          typically has its own communication methods.
+
+          To compile this driver as a module, choose M here: the
+          module will be called cros_ec_lpc.
 
 endif # CHROMEOS_PLATFORMS

drivers/platform/chrome/Makefile

 
 obj-$(CONFIG_CHROMEOS_LAPTOP)	+= chromeos_laptop.o
 obj-$(CONFIG_CHROMEOS_PSTORE)	+= chromeos_pstore.o
+cros_ec_devs-objs               := cros_ec_dev.o cros_ec_sysfs.o cros_ec_lightbar.o
+obj-$(CONFIG_CROS_EC_CHARDEV)   += cros_ec_devs.o
+obj-$(CONFIG_CROS_EC_LPC)       += cros_ec_lpc.o

drivers/platform/chrome/chromeos_laptop.c

@@ -133,12 +133,13 @@ static struct i2c_client *__add_probed_i2c_device(
 		const char *name,
 		int bus,
 		struct i2c_board_info *info,
-		const unsigned short *addrs)
+		const unsigned short *alt_addr_list)
 {
 	const struct dmi_device *dmi_dev;
 	const struct dmi_dev_onboard *dev_data;
 	struct i2c_adapter *adapter;
-	struct i2c_client *client;
+	struct i2c_client *client = NULL;
+	const unsigned short addr_list[] = { info->addr, I2C_CLIENT_END };
 
 	if (bus < 0)
 		return NULL;
@@ -169,8 +170,28 @@ static struct i2c_client *__add_probed_i2c_device(
 		return NULL;
 	}
 
-	/* add the i2c device */
-	client = i2c_new_probed_device(adapter, info, addrs, NULL);
+	/*
+	 * Add the i2c device. If we can't detect it at the primary
+	 * address we scan secondary addresses. In any case the client
+	 * structure gets assigned primary address.
+	 */
+	client = i2c_new_probed_device(adapter, info, addr_list, NULL);
+	if (!client && alt_addr_list) {
+		struct i2c_board_info dummy_info = {
+			I2C_BOARD_INFO("dummy", info->addr),
+		};
+		struct i2c_client *dummy;
+
+		dummy = i2c_new_probed_device(adapter, &dummy_info,
+					      alt_addr_list, NULL);
+		if (dummy) {
+			pr_debug("%s %d-%02x is probed at %02x\n",
+				  __func__, bus, info->addr, dummy->addr);
+			i2c_unregister_device(dummy);
+			client = i2c_new_device(adapter, info);
+		}
+	}
+
 	if (!client)
 		pr_notice("%s failed to register device %d-%02x\n",
 			  __func__, bus, info->addr);
@@ -254,12 +275,10 @@ static struct i2c_client *add_i2c_device(const char *name,
 						enum i2c_adapter_type type,
 						struct i2c_board_info *info)
 {
-	const unsigned short addr_list[] = { info->addr, I2C_CLIENT_END };
-
 	return __add_probed_i2c_device(name,
 				       find_i2c_adapter_num(type),
 				       info,
-				       addr_list);
+				       NULL);
 }
 
 static int setup_cyapa_tp(enum i2c_adapter_type type)
@@ -275,7 +294,6 @@ static int setup_cyapa_tp(enum i2c_adapter_type type)
 static int setup_atmel_224s_tp(enum i2c_adapter_type type)
 {
 	const unsigned short addr_list[] = { ATMEL_TP_I2C_BL_ADDR,
-					     ATMEL_TP_I2C_ADDR,
 					     I2C_CLIENT_END };
 	if (tp)
 		return 0;
@@ -289,7 +307,6 @@ static int setup_atmel_224s_tp(enum i2c_adapter_type type)
 static int setup_atmel_1664s_ts(enum i2c_adapter_type type)
 {
 	const unsigned short addr_list[] = { ATMEL_TS_I2C_BL_ADDR,
-					     ATMEL_TS_I2C_ADDR,
 					     I2C_CLIENT_END };
 	if (ts)
 		return 0;

drivers/platform/chrome/cros_ec_dev.c

+/*
+ * 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/module.h>
+#include <linux/platform_device.h>
+#include <linux/uaccess.h>
+
+#include "cros_ec_dev.h"
+
+/* Device variables */
+#define CROS_MAX_DEV 128
+static struct class *cros_class;
+static int ec_major;
+
+/* Basic communication */
+static int ec_get_version(struct cros_ec_device *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 = {
+		.version = 0,
+		.command = EC_CMD_GET_VERSION,
+		.outdata = { 0 },
+		.outsize = 0,
+		.indata = { 0 },
+		.insize = sizeof(*resp),
+	};
+	int ret;
+
+	ret = cros_ec_cmd_xfer(ec, &msg);
+	if (ret < 0)
+		return ret;
+
+	if (msg.result != EC_RES_SUCCESS) {
+		snprintf(str, maxlen,
+			 "%s\nUnknown EC version: EC returned %d\n",
+			 CROS_EC_DEV_VERSION, msg.result);
+		return 0;
+	}
+
+	resp = (struct ec_response_get_version *)msg.indata;
+	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]);
+
+	return 0;
+}
+
+/* Device file ops */
+static int ec_device_open(struct inode *inode, struct file *filp)
+{
+	filp->private_data = container_of(inode->i_cdev,
+					  struct cros_ec_device, cdev);
+	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_device *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_device *ec, void __user *arg)
+{
+	long ret;
+	struct cros_ec_command s_cmd = { };
+
+	if (copy_from_user(&s_cmd, arg, sizeof(s_cmd)))
+		return -EFAULT;
+
+	ret = cros_ec_cmd_xfer(ec, &s_cmd);
+	/* Only copy data to userland if data was received. */
+	if (ret < 0)
+		return ret;
+
+	if (copy_to_user(arg, &s_cmd, sizeof(s_cmd)))
+		return -EFAULT;
+
+	return 0;
+}
+
+static long ec_device_ioctl_readmem(struct cros_ec_device *ec, void __user *arg)
+{
+	struct cros_ec_readmem s_mem = { };
+	long num;
+
+	/* Not every platform supports direct reads */
+	if (!ec->cmd_readmem)
+		return -ENOTTY;
+
+	if (copy_from_user(&s_mem, arg, sizeof(s_mem)))
+		return -EFAULT;
+
+	num = ec->cmd_readmem(ec, 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_device *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,
+};
+
+static int ec_device_probe(struct platform_device *pdev)
+{
+	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
+	int retval = -ENOTTY;
+	dev_t devno = MKDEV(ec_major, 0);
+
+	/* Instantiate it (and remember the EC) */
+	cdev_init(&ec->cdev, &fops);
+
+	retval = cdev_add(&ec->cdev, devno, 1);
+	if (retval) {
+		dev_err(&pdev->dev, ": failed to add character device\n");
+		return retval;
+	}
+
+	ec->vdev = device_create(cros_class, NULL, devno, ec,
+				 CROS_EC_DEV_NAME);
+	if (IS_ERR(ec->vdev)) {
+		retval = PTR_ERR(ec->vdev);
+		dev_err(&pdev->dev, ": failed to create device\n");
+		cdev_del(&ec->cdev);
+		return retval;
+	}
+
+	/* Initialize extra interfaces */
+	ec_dev_sysfs_init(ec);
+	ec_dev_lightbar_init(ec);
+
+	return 0;
+}
+
+static int ec_device_remove(struct platform_device *pdev)
+{
+	struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent);
+
+	ec_dev_lightbar_remove(ec);
+	ec_dev_sysfs_remove(ec);
+	device_destroy(cros_class, MKDEV(ec_major, 0));
+	cdev_del(&ec->cdev);
+	return 0;
+}
+
+static struct platform_driver cros_ec_dev_driver = {
+	.driver = {
+		.name = "cros-ec-ctl",
+	},
+	.probe = ec_device_probe,
+	.remove = ec_device_remove,
+};
+
+static int __init cros_ec_dev_init(void)
+{
+	int ret;
+	dev_t dev = 0;
+
+	cros_class = class_create(THIS_MODULE, "chromeos");
+	if (IS_ERR(cros_class)) {
+		pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
+		return PTR_ERR(cros_class);
+	}
+
+	/* 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_destroy(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_destroy(cros_class);
+}
+
+module_init(cros_ec_dev_init);
+module_exit(cros_ec_dev_exit);
+
+MODULE_AUTHOR("Bill Richardson <wfrichar@chromium.org>");
+MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
+MODULE_VERSION("1.0");
+MODULE_LICENSE("GPL");

drivers/platform/chrome/cros_ec_dev.h

+/*
+ * cros_ec_dev - expose the Chrome OS Embedded Controller to userspace
+ *
+ * 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/>.
+ */
+
+#ifndef _CROS_EC_DEV_H_
+#define _CROS_EC_DEV_H_
+
+#include <linux/ioctl.h>
+#include <linux/types.h>
+#include <linux/mfd/cros_ec.h>
+
+#define CROS_EC_DEV_NAME "cros_ec"
+#define CROS_EC_DEV_VERSION "1.0.0"
+
+/*
+ * @offset: within EC_LPC_ADDR_MEMMAP region
+ * @bytes: number of bytes to read. zero means "read a string" (including '\0')
+ *         (at most only EC_MEMMAP_SIZE bytes can be read)
+ * @buffer: where to store the result
+ * ioctl returns the number of bytes read, negative on error
+ */
+struct cros_ec_readmem {
+	uint32_t offset;
+	uint32_t bytes;
+	uint8_t buffer[EC_MEMMAP_SIZE];
+};
+
+#define CROS_EC_DEV_IOC       0xEC
+#define CROS_EC_DEV_IOCXCMD   _IOWR(CROS_EC_DEV_IOC, 0, struct cros_ec_command)
+#define CROS_EC_DEV_IOCRDMEM  _IOWR(CROS_EC_DEV_IOC, 1, struct cros_ec_readmem)
+
+void ec_dev_sysfs_init(struct cros_ec_device *);
+void ec_dev_sysfs_remove(struct cros_ec_device *);
+
+void ec_dev_lightbar_init(struct cros_ec_device *);
+void ec_dev_lightbar_remove(struct cros_ec_device *);
+
+#endif /* _CROS_EC_DEV_H_ */

drivers/platform/chrome/cros_ec_lightbar.c

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

drivers/platform/chrome/cros_ec_lpc.c

+/*
+ * cros_ec_lpc - LPC access to the Chrome OS Embedded Controller
+ *
+ * Copyright (C) 2012-2015 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.
+ *
+ * This driver uses the Chrome OS EC byte-level message-based protocol for
+ * communicating the keyboard state (which keys are pressed) from a keyboard EC
+ * to the AP over some bus (such as i2c, lpc, spi).  The EC does debouncing,
+ * but everything else (including deghosting) is done here.  The main
+ * motivation for this is to keep the EC firmware as simple as possible, since
+ * it cannot be easily upgraded and EC flash/IRAM space is relatively
+ * expensive.
+ */
+
+#include <linux/dmi.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/mfd/cros_ec.h>
+#include <linux/mfd/cros_ec_commands.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+
+#define DRV_NAME "cros_ec_lpc"
+
+static int ec_response_timed_out(void)
+{
+	unsigned long one_second = jiffies + HZ;
+
+	usleep_range(200, 300);
+	do {
+		if (!(inb(EC_LPC_ADDR_HOST_CMD) & EC_LPC_STATUS_BUSY_MASK))
+			return 0;
+		usleep_range(100, 200);
+	} while (time_before(jiffies, one_second));
+
+	return 1;
+}
+
+static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,
+				struct cros_ec_command *msg)
+{
+	struct ec_lpc_host_args args;
+	int csum;
+	int i;
+	int ret = 0;
+
+	if (msg->outsize > EC_PROTO2_MAX_PARAM_SIZE ||
+	    msg->insize > EC_PROTO2_MAX_PARAM_SIZE) {
+		dev_err(ec->dev,
+			"invalid buffer sizes (out %d, in %d)\n",
+			msg->outsize, msg->insize);
+		return -EINVAL;
+	}
+
+	/* Now actually send the command to the EC and get the result */
+	args.flags = EC_HOST_ARGS_FLAG_FROM_HOST;
+	args.command_version = msg->version;
+	args.data_size = msg->outsize;
+
+	/* Initialize checksum */
+	csum = msg->command + args.flags +
+		args.command_version + args.data_size;
+
+	/* Copy data and update checksum */
+	for (i = 0; i < msg->outsize; i++) {
+		outb(msg->outdata[i], EC_LPC_ADDR_HOST_PARAM + i);
+		csum += msg->outdata[i];
+	}
+
+	/* Finalize checksum and write args */
+	args.checksum = csum & 0xFF;
+	outb(args.flags, EC_LPC_ADDR_HOST_ARGS);
+	outb(args.command_version, EC_LPC_ADDR_HOST_ARGS + 1);
+	outb(args.data_size, EC_LPC_ADDR_HOST_ARGS + 2);
+	outb(args.checksum, EC_LPC_ADDR_HOST_ARGS + 3);
+
+	/* Here we go */
+	outb(msg->command, EC_LPC_ADDR_HOST_CMD);
+
+	if (ec_response_timed_out()) {
+		dev_warn(ec->dev, "EC responsed timed out\n");
+		ret = -EIO;
+		goto done;
+	}
+
+	/* Check result */
+	msg->result = inb(EC_LPC_ADDR_HOST_DATA);
+
+	switch (msg->result) {
+	case EC_RES_SUCCESS:
+		break;
+	case EC_RES_IN_PROGRESS:
+		ret = -EAGAIN;
+		dev_dbg(ec->dev, "command 0x%02x in progress\n",
+			msg->command);
+		goto done;
+	default:
+		dev_dbg(ec->dev, "command 0x%02x returned %d\n",
+			msg->command, msg->result);
+	}
+
+	/* Read back args */
+	args.flags = inb(EC_LPC_ADDR_HOST_ARGS);
+	args.command_version = inb(EC_LPC_ADDR_HOST_ARGS + 1);
+	args.data_size = inb(EC_LPC_ADDR_HOST_ARGS + 2);
+	args.checksum = inb(EC_LPC_ADDR_HOST_ARGS + 3);
+
+	if (args.data_size > msg->insize) {
+		dev_err(ec->dev,
+			"packet too long (%d bytes, expected %d)",
+			args.data_size, msg->insize);
+		ret = -ENOSPC;
+		goto done;
+	}
+
+	/* Start calculating response checksum */
+	csum = msg->command + args.flags +
+		args.command_version + args.data_size;
+
+	/* Read response and update checksum */
+	for (i = 0; i < args.data_size; i++) {
+		msg->indata[i] = inb(EC_LPC_ADDR_HOST_PARAM + i);
+		csum += msg->indata[i];
+	}
+
+	/* Verify checksum */
+	if (args.checksum != (csum & 0xFF)) {
+		dev_err(ec->dev,
+			"bad packet checksum, expected %02x, got %02x\n",
+			args.checksum, csum & 0xFF);
+		ret = -EBADMSG;
+		goto done;
+	}
+
+	/* Return actual amount of data received */
+	ret = args.data_size;
+done:
+	return ret;
+}
+
+/* Returns num bytes read, or negative on error. Doesn't need locking. */
+static int cros_ec_lpc_readmem(struct cros_ec_device *ec, unsigned int offset,
+			       unsigned int bytes, void *dest)
+{
+	int i = offset;
+	char *s = dest;
+	int cnt = 0;
+
+	if (offset >= EC_MEMMAP_SIZE - bytes)
+		return -EINVAL;
+
+	/* fixed length */
+	if (bytes) {
+		for (; cnt < bytes; i++, s++, cnt++)
+			*s = inb(EC_LPC_ADDR_MEMMAP + i);
+		return cnt;
+	}
+
+	/* string */
+	for (; i < EC_MEMMAP_SIZE; i++, s++) {
+		*s = inb(EC_LPC_ADDR_MEMMAP + i);
+		cnt++;
+		if (!*s)
+			break;
+	}
+
+	return cnt;
+}
+
+static int cros_ec_lpc_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct cros_ec_device *ec_dev;
+	int ret;
+
+	if (!devm_request_region(dev, EC_LPC_ADDR_MEMMAP, EC_MEMMAP_SIZE,
+				 dev_name(dev))) {
+		dev_err(dev, "couldn't reserve memmap region\n");
+		return -EBUSY;
+	}
+
+	if ((inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID) != 'E') ||
+	    (inb(EC_LPC_ADDR_MEMMAP + EC_MEMMAP_ID + 1) != 'C')) {
+		dev_err(dev, "EC ID not detected\n");
+		return -ENODEV;
+	}
+
+	if (!devm_request_region(dev, EC_HOST_CMD_REGION0,
+				 EC_HOST_CMD_REGION_SIZE, dev_name(dev))) {
+		dev_err(dev, "couldn't reserve region0\n");
+		return -EBUSY;
+	}
+	if (!devm_request_region(dev, EC_HOST_CMD_REGION1,
+				 EC_HOST_CMD_REGION_SIZE, dev_name(dev))) {
+		dev_err(dev, "couldn't reserve region1\n");
+		return -EBUSY;
+	}
+
+	ec_dev = devm_kzalloc(dev, sizeof(*ec_dev), GFP_KERNEL);
+	if (!ec_dev)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, ec_dev);
+	ec_dev->dev = dev;
+	ec_dev->ec_name = pdev->name;
+	ec_dev->phys_name = dev_name(dev);
+	ec_dev->parent = dev;
+	ec_dev->cmd_xfer = cros_ec_cmd_xfer_lpc;
+	ec_dev->cmd_readmem = cros_ec_lpc_readmem;
+
+	ret = cros_ec_register(ec_dev);
+	if (ret) {
+		dev_err(dev, "couldn't register ec_dev (%d)\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static int cros_ec_lpc_remove(struct platform_device *pdev)
+{
+	struct cros_ec_device *ec_dev;
+
+	ec_dev = platform_get_drvdata(pdev);
+	cros_ec_remove(ec_dev);
+
+	return 0;
+}
+
+static struct dmi_system_id cros_ec_lpc_dmi_table[] __initdata = {
+	{
+		/*
+		 * Today all Chromebooks/boxes ship with Google_* as version and
+		 * coreboot as bios vendor. No other systems with this
+		 * combination are known to date.
+		 */
+		.matches = {
+			DMI_MATCH(DMI_BIOS_VENDOR, "coreboot"),
+			DMI_MATCH(DMI_BIOS_VERSION, "Google_"),
+		},
+	},
+	{
+		/* x86-link, the Chromebook Pixel. */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Link"),
+		},
+	},
+	{
+		/* x86-peppy, the Acer C720 Chromebook. */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Peppy"),
+		},
+	},
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(dmi, cros_ec_lpc_dmi_table);
+
+static struct platform_driver cros_ec_lpc_driver = {
+	.driver = {
+		.name = DRV_NAME,
+	},
+	.probe = cros_ec_lpc_probe,
+	.remove = cros_ec_lpc_remove,
+};
+
+static struct platform_device cros_ec_lpc_device = {
+	.name = DRV_NAME
+};
+
+static int __init cros_ec_lpc_init(void)
+{
+	int ret;
+
+	if (!dmi_check_system(cros_ec_lpc_dmi_table)) {
+		pr_err(DRV_NAME ": unsupported system.\n");
+		return -ENODEV;
+	}
+
+	/* Register the driver */
+	ret = platform_driver_register(&cros_ec_lpc_driver);
+	if (ret) {
+		pr_err(DRV_NAME ": can't register driver: %d\n", ret);
+		return ret;
+	}
+
+	/* Register the device, and it'll get hooked up automatically */
+	ret = platform_device_register(&cros_ec_lpc_device);
+	if (ret) {
+		pr_err(DRV_NAME ": can't register device: %d\n", ret);
+		platform_driver_unregister(&cros_ec_lpc_driver);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __exit cros_ec_lpc_exit(void)
+{
+	platform_device_unregister(&cros_ec_lpc_device);
+	platform_driver_unregister(&cros_ec_lpc_driver);
+}
+
+module_init(cros_ec_lpc_init);
+module_exit(cros_ec_lpc_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("ChromeOS EC LPC driver");

drivers/platform/chrome/cros_ec_sysfs.c

+/*
+ * cros_ec_sysfs - expose the Chrome OS EC through sysfs
+ *
+ * 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/>.
+ */
+
+#define pr_fmt(fmt) "cros_ec_sysfs: " fmt
+
+#include <linux/ctype.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/kobject.h>
+#include <linux/mfd/cros_ec.h>
+#include <linux/mfd/cros_ec_commands.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+#include <linux/stat.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+#include "cros_ec_dev.h"
+
+/* Accessor functions */
+
+static ssize_t show_ec_reboot(struct device *dev,
+			      struct device_attribute *attr, char *buf)
+{
+	int count = 0;
+
+	count += scnprintf(buf + count, PAGE_SIZE - count,
+			   "ro|rw|cancel|cold|disable-jump|hibernate");
+	count += scnprintf(buf + count, PAGE_SIZE - count,
+			   " [at-shutdown]\n");
+	return count;
+}
+
+static ssize_t store_ec_reboot(struct device *dev,
+			       struct device_attribute *attr,
+			       const char *buf, size_t count)
+{
+	static const struct {
+		const char * const str;
+		uint8_t cmd;
+		uint8_t flags;
+	} words[] = {
+		{"cancel",       EC_REBOOT_CANCEL, 0},
+		{"ro",           EC_REBOOT_JUMP_RO, 0},
+		{"rw",           EC_REBOOT_JUMP_RW, 0},
+		{"cold",         EC_REBOOT_COLD, 0},
+		{"disable-jump", EC_REBOOT_DISABLE_JUMP, 0},
+		{"hibernate",    EC_REBOOT_HIBERNATE, 0},
+		{"at-shutdown",  -1, EC_REBOOT_FLAG_ON_AP_SHUTDOWN},
+	};
+	struct cros_ec_command msg = { 0 };
+	struct ec_params_reboot_ec *param =
+		(struct ec_params_reboot_ec *)msg.outdata;
+	int got_cmd = 0, offset = 0;
+	int i;
+	int ret;
+	struct cros_ec_device *ec = dev_get_drvdata(dev);
+
+	param->flags = 0;
+	while (1) {
+		/* Find word to start scanning */
+		while (buf[offset] && isspace(buf[offset]))
+			offset++;
+		if (!buf[offset])
+			break;
+
+		for (i = 0; i < ARRAY_SIZE(words); i++) {
+			if (!strncasecmp(words[i].str, buf+offset,
+					 strlen(words[i].str))) {
+				if (words[i].flags) {
+					param->flags |= words[i].flags;
+				} else {
+					param->cmd = words[i].cmd;
+					got_cmd = 1;
+				}
+				break;
+			}
+		}
+
+		/* On to the next word, if any */
+		while (buf[offset] && !isspace(buf[offset]))
+			offset++;
+	}
+
+	if (!got_cmd)
+		return -EINVAL;
+
+	msg.command = EC_CMD_REBOOT_EC;
+	msg.outsize = sizeof(param);
+	ret = cros_ec_cmd_xfer(ec, &msg);
+	if (ret < 0)
+		return ret;
+	if (msg.result != EC_RES_SUCCESS) {
+		dev_dbg(ec->dev, "EC result %d\n", msg.result);
+		return -EINVAL;
+	}
+
+	return count;
+}
+
+static ssize_t show_ec_version(struct device *dev,
+			       struct device_attribute *attr, char *buf)
+{
+	static const char * const image_names[] = {"unknown", "RO", "RW"};
+	struct ec_response_get_version *r_ver;
+	struct ec_response_get_chip_info *r_chip;
+	struct ec_response_board_version *r_board;
+	struct cros_ec_command msg = { 0 };
+	int ret;
+	int count = 0;
+	struct cros_ec_device *ec = dev_get_drvdata(dev);
+
+	/* Get versions. RW may change. */
+	msg.command = EC_CMD_GET_VERSION;
+	msg.insize = sizeof(*r_ver);
+	ret = cros_ec_cmd_xfer(ec, &msg);
+	if (ret < 0)
+		return ret;
+	if (msg.result != EC_RES_SUCCESS)
+		return scnprintf(buf, PAGE_SIZE,
+				 "ERROR: EC returned %d\n", msg.result);
+
+	r_ver = (struct ec_response_get_version *)msg.indata;
+	/* Strings should be null-terminated, but let's be sure. */
+	r_ver->version_string_ro[sizeof(r_ver->version_string_ro) - 1] = '\0';
+	r_ver->version_string_rw[sizeof(r_ver->version_string_rw) - 1] = '\0';
+	count += scnprintf(buf + count, PAGE_SIZE - count,
+			   "RO version:    %s\n", r_ver->version_string_ro);
+	count += scnprintf(buf + count, PAGE_SIZE - count,
+			   "RW version:    %s\n", r_ver->version_string_rw);
+	count += scnprintf(buf + count, PAGE_SIZE - count,
+			   "Firmware copy: %s\n",
+			   (r_ver->current_image < ARRAY_SIZE(image_names) ?
+			    image_names[r_ver->current_image] : "?"));
+
+	/* Get build info. */
+	msg.command = EC_CMD_GET_BUILD_INFO;
+	msg.insize = sizeof(msg.indata);
+	ret = cros_ec_cmd_xfer(ec, &msg);
+	if (ret < 0)
+		count += scnprintf(buf + count, PAGE_SIZE - count,
+				   "Build info:    XFER ERROR %d\n", ret);
+	else if (msg.result != EC_RES_SUCCESS)
+		count += scnprintf(buf + count, PAGE_SIZE - count,
+				   "Build info:    EC error %d\n", msg.result);
+	else {
+		msg.indata[sizeof(msg.indata) - 1] = '\0';
+		count += scnprintf(buf + count, PAGE_SIZE - count,
+				   "Build info:    %s\n", msg.indata);
+	}
+
+	/* Get chip info. */
+	msg.command = EC_CMD_GET_CHIP_INFO;
+	msg.insize = sizeof(*r_chip);
+	ret = cros_ec_cmd_xfer(ec, &msg);
+	if (ret < 0)
+		count += scnprintf(buf + count, PAGE_SIZE - count,
+				   "Chip info:     XFER ERROR %d\n", ret);
+	else if (msg.result != EC_RES_SUCCESS)
+		count += scnprintf(buf + count, PAGE_SIZE - count,
+				   "Chip info:     EC error %d\n", msg.result);
+	else {
+		r_chip = (struct ec_response_get_chip_info *)msg.indata;
+
+		r_chip->vendor[sizeof(r_chip->vendor) - 1] = '\0';
+		r_chip->name[sizeof(r_chip->name) - 1] = '\0';
+		r_chip->revision[sizeof(r_chip->revision) - 1] = '\0';
+		count += scnprintf(buf + count, PAGE_SIZE - count,
+				   "Chip vendor:   %s\n", r_chip->vendor);
+		count += scnprintf(buf + count, PAGE_SIZE - count,
+				   "Chip name:     %s\n", r_chip->name);
+		count += scnprintf(buf + count, PAGE_SIZE - count,
+				   "Chip revision: %s\n", r_chip->revision);
+	}
+
+	/* Get board version */
+	msg.command = EC_CMD_GET_BOARD_VERSION;
+	msg.insize = sizeof(*r_board);
+	ret = cros_ec_cmd_xfer(ec, &msg);
+	if (ret < 0)
+		count += scnprintf(buf + count, PAGE_SIZE - count,
+				   "Board version: XFER ERROR %d\n", ret);
+	else if (msg.result != EC_RES_SUCCESS)
+		count += scnprintf(buf + count, PAGE_SIZE - count,
+				   "Board version: EC error %d\n", msg.result);
+	else {
+		r_board = (struct ec_response_board_version *)msg.indata;
+
+		count += scnprintf(buf + count, PAGE_SIZE - count,
+				   "Board version: %d\n",
+				   r_board->board_version);
+	}
+
+	return count;
+}
+
+static ssize_t show_ec_flashinfo(struct device *dev,
+				 struct device_attribute *attr, char *buf)
+{
+	struct ec_response_flash_info *resp;
+	struct cros_ec_command msg = { 0 };
+	int ret;
+	struct cros_ec_device *ec = dev_get_drvdata(dev);
+
+	/* The flash info shouldn't ever change, but ask each time anyway. */
+	msg.command = EC_CMD_FLASH_INFO;
+	msg.insize = sizeof(*resp);
+	ret = cros_ec_cmd_xfer(ec, &msg);
+	if (ret < 0)
+		return ret;
+	if (msg.result != EC_RES_SUCCESS)
+		return scnprintf(buf, PAGE_SIZE,
+				 "ERROR: EC returned %d\n", msg.result);
+
+	resp = (struct ec_response_flash_info *)msg.indata;
+
+	return scnprintf(buf, PAGE_SIZE,
+			 "FlashSize %d\nWriteSize %d\n"
+			 "EraseSize %d\nProtectSize %d\n",
+			 resp->flash_size, resp->write_block_size,
+			 resp->erase_block_size, resp->protect_block_size);
+}
+
+/* Module initialization */
+
+static DEVICE_ATTR(reboot, S_IWUSR | S_IRUGO, show_ec_reboot, store_ec_reboot);
+static DEVICE_ATTR(version, S_IRUGO, show_ec_version, NULL);
+static DEVICE_ATTR(flashinfo, S_IRUGO, show_ec_flashinfo, NULL);
+
+static struct attribute *__ec_attrs[] = {
+	&dev_attr_reboot.attr,
+	&dev_attr_version.attr,
+	&dev_attr_flashinfo.attr,
+	NULL,
+};
+
+static struct attribute_group ec_attr_group = {
+	.attrs = __ec_attrs,
+};
+
+void ec_dev_sysfs_init(struct cros_ec_device *ec)
+{
+	int error;
+
+	error = sysfs_create_group(&ec->vdev->kobj, &ec_attr_group);
+	if (error)
+		pr_warn("failed to create group: %d\n", error);
+}
+
+void ec_dev_sysfs_remove(struct cros_ec_device *ec)
+{
+	sysfs_remove_group(&ec->vdev->kobj, &ec_attr_group);
+}

include/linux/mfd/cros_ec.h

@@ -16,6 +16,7 @@
 #ifndef __LINUX_MFD_CROS_EC_H
 #define __LINUX_MFD_CROS_EC_H
 
+#include <linux/cdev.h>
 #include <linux/notifier.h>
 #include <linux/mfd/cros_ec_commands.h>
 #include <linux/mutex.h>
@@ -38,20 +39,20 @@ enum {
 /*
  * @version: Command version number (often 0)
  * @command: Command to send (EC_CMD_...)
- * @outdata: Outgoing data to EC
  * @outsize: Outgoing length in bytes
- * @indata: Where to put the incoming data from EC
  * @insize: Max number of bytes to accept from EC
  * @result: EC's response to the command (separate from communication failure)
+ * @outdata: Outgoing data to EC
+ * @indata: Where to put the incoming data from EC
  */
 struct cros_ec_command {
 	uint32_t version;
 	uint32_t command;
-	uint8_t *outdata;
 	uint32_t outsize;
-	uint8_t *indata;
 	uint32_t insize;
 	uint32_t result;
+	uint8_t outdata[EC_PROTO2_MAX_PARAM_SIZE];
+	uint8_t indata[EC_PROTO2_MAX_PARAM_SIZE];
 };
 
 /**
@@ -59,9 +60,17 @@ struct cros_ec_command {
  *
  * @ec_name: name of EC device (e.g. 'chromeos-ec')
  * @phys_name: name of physical comms layer (e.g. 'i2c-4')
- * @dev: Device pointer
+ * @dev: Device pointer for physical comms device
+ * @vdev: Device pointer for virtual comms device
+ * @cdev: Character device structure for virtual comms device
  * @was_wake_device: true if this device was set to wake the system from
  * sleep at the last suspend
+ * @cmd_readmem: direct read of the EC memory-mapped region, if supported
+ *     @offset is within EC_LPC_ADDR_MEMMAP region.
+ *     @bytes: number of bytes to read. zero means "read a string" (including
+ *     the trailing '\0'). At most only EC_MEMMAP_SIZE bytes can be read.
+ *     Caller must ensure that the buffer is large enough for the result when
+ *     reading a string.
  *
  * @priv: Private data
  * @irq: Interrupt to use
@@ -90,8 +99,12 @@ struct cros_ec_device {
 	const char *ec_name;
 	const char *phys_name;
 	struct device *dev;
+	struct device *vdev;
+	struct cdev cdev;
 	bool was_wake_device;
 	struct class *cros_class;
+	int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
+			   unsigned int bytes, void *dest);
 
 	/* These are used to implement the platform-specific interface */
 	void *priv;