On Fri, Jan 2, 2015 at 5:32 AM, Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx> wrote: > > From: Bill Richardson <wfrichar@xxxxxxxxxxxx> > > This patch adds a device interface to access the > Chrome OS Embedded Controller from user-space. > > Signed-off-by: Bill Richardson <wfrichar@xxxxxxxxxxxx> > Reviewed-by: Simon Glass <sjg@xxxxxxxxxx> > Signed-off-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx> Reviewed-by: Gwendal Grignou <gwendal@xxxxxxxxxxxx> > --- > > Changes since v1: > - The cros_ec_dev driver does not belong to drivers/mfd (Lee Jones) > - Don't call class_create in the probe function (Gwendal Grignou) > - Don't use the deprecated register_chrdev() function (Gwendal Grignou) > - Remove struct cros_ec_device *ec global variable (Lee Jones) > - Arrange structures to be 64-bit safe instead using the IOCTL compact API > (Alan Cox) > - Use _CHARDEV instead of _DEV as a postfix to denote that is a character > device user-space interface (Lee Jones) > - Remove the CROS_CLASS_NAME define and just use the name directly (Lee Jones) > - Remove unncessary include headers (Lee Jones) > - Add a newline when appropiate and remove double new lines (Lee Jones) > - If *offset == 0, there is no need to do *offset +=, just use = (Lee Jones) > - Use dev_err() instead of pr_err() when possible (Lee Jones) > - Remove unnecesary goto and just return an error instead (Lee Jones) > - Don't set .owner to THIS_MODULE since that is made by the core (Lee Jones) > - Document the ioctl number used in Documentation/ioctl/ioctl-number.txt > > Documentation/ioctl/ioctl-number.txt | 1 + > drivers/platform/chrome/Kconfig | 14 +- > drivers/platform/chrome/Makefile | 1 + > drivers/platform/chrome/cros_ec_dev.c | 268 ++++++++++++++++++++++++++++++++++ > drivers/platform/chrome/cros_ec_dev.h | 47 ++++++ > 5 files changed, 328 insertions(+), 3 deletions(-) > create mode 100644 drivers/platform/chrome/cros_ec_dev.c > create mode 100644 drivers/platform/chrome/cros_ec_dev.h > > diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt > index 8136e1f..51f4221 100644 > --- a/Documentation/ioctl/ioctl-number.txt > +++ b/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@xxxxxxxxxx> > +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@xxxxxxxxxxxxxxxx> > 0xF4 00-1F video/mbxfb.h mbxfb > diff --git a/drivers/platform/chrome/Kconfig b/drivers/platform/chrome/Kconfig > index 440ed77..75dc514 100644 > --- a/drivers/platform/chrome/Kconfig > +++ b/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 +38,13 @@ 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. > > endif # CHROMEOS_PLATFORMS > diff --git a/drivers/platform/chrome/Makefile b/drivers/platform/chrome/Makefile > index 2b860ca..10f1361 100644 > --- a/drivers/platform/chrome/Makefile > +++ b/drivers/platform/chrome/Makefile > @@ -1,3 +1,4 @@ > > obj-$(CONFIG_CHROMEOS_LAPTOP) += chromeos_laptop.o > obj-$(CONFIG_CHROMEOS_PSTORE) += chromeos_pstore.o > +obj-$(CONFIG_CROS_EC_CHARDEV) += cros_ec_dev.o > diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c > new file mode 100644 > index 0000000..04cc8eb > --- /dev/null > +++ b/drivers/platform/chrome/cros_ec_dev.c > @@ -0,0 +1,268 @@ > +/* > + * 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; > + } > + > + return 0; > +} > + > +static int ec_device_remove(struct platform_device *pdev) > +{ > + struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent); > + > + 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-dev", > + }, > + .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@xxxxxxxxxxxx>"); > +MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller"); > +MODULE_VERSION("1.0"); > +MODULE_LICENSE("GPL"); > diff --git a/drivers/platform/chrome/cros_ec_dev.h b/drivers/platform/chrome/cros_ec_dev.h > new file mode 100644 > index 0000000..15c54c4 > --- /dev/null > +++ b/drivers/platform/chrome/cros_ec_dev.h > @@ -0,0 +1,47 @@ > +/* > + * 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) > + > +#endif /* _CROS_EC_DEV_H_ */ > -- > 2.1.3 > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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