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Message-Id: <1416238213-15263-2-git-send-email-javier.martinez@collabora.co.uk>
Date: Mon, 17 Nov 2014 16:30:11 +0100
From: Javier Martinez Canillas <javier.martinez@...labora.co.uk>
To: Lee Jones <lee.jones@...aro.org>
Cc: Doug Anderson <dianders@...omium.org>,
Bill Richardson <wfrichar@...omium.org>,
Olof Johansson <olof@...om.net>, Simon Glass <sjg@...gle.com>,
Gwendal Grignou <gwendal@...gle.com>,
linux-kernel@...r.kernel.org,
Javier Martinez Canillas <javier.martinez@...labora.co.uk>
Subject: [PATCH 1/3] mfd: cros_ec: Add Chrome OS EC userspace device interface
From: Bill Richardson <wfrichar@...omium.org>
This patch adds a device interface to access the
ChromeOS Embedded Controller from user-space.
Signed-off-by: Bill Richardson <wfrichar@...omium.org>
Reviewed-on: https://gerrit-int.chromium.org/38364
Reviewed-by: Simon Glass <sjg@...gle.com>
Tested-by: Simon Glass <sjg@...gle.com>
Signed-off-by: Javier Martinez Canillas <javier.martinez@...labora.co.uk>
---
drivers/mfd/Kconfig | 12 ++
drivers/mfd/Makefile | 1 +
drivers/mfd/cros_ec.c | 4 +
drivers/mfd/cros_ec_dev.c | 355 ++++++++++++++++++++++++++++++++++++++++
include/linux/mfd/cros_ec.h | 12 +-
include/linux/mfd/cros_ec_dev.h | 47 ++++++
6 files changed, 430 insertions(+), 1 deletion(-)
create mode 100644 drivers/mfd/cros_ec_dev.c
create mode 100644 include/linux/mfd/cros_ec_dev.h
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 72d3808..31420a7 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -115,6 +115,18 @@ config MFD_CROS_EC_SPI
response time cannot be guaranteed, we support ignoring
'pre-amble' bytes before the response actually starts.
+config MFD_CROS_EC_DEV
+ tristate "ChromeOS Embedded Controller userspace device interface"
+ depends on MFD_CROS_EC
+
+ help
+ If you say Y here, you get support for talking to the ChromeOS
+ EC from userspace. This is separate from the normal kernel
+ interfaces.
+
+ To compile this driver as a module, choose M here: the module will be
+ called cros_ec_dev.
+
config MFD_ASIC3
bool "Compaq ASIC3"
depends on GPIOLIB && ARM
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 53467e2..5104a25 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -12,6 +12,7 @@ obj-$(CONFIG_MFD_BCM590XX) += bcm590xx.o
obj-$(CONFIG_MFD_CROS_EC) += cros_ec.o
obj-$(CONFIG_MFD_CROS_EC_I2C) += cros_ec_i2c.o
obj-$(CONFIG_MFD_CROS_EC_SPI) += cros_ec_spi.o
+obj-$(CONFIG_MFD_CROS_EC_DEV) += cros_ec_dev.o
rtsx_pci-objs := rtsx_pcr.o rtsx_gops.o rts5209.o rts5229.o rtl8411.o rts5227.o rts5249.o
obj-$(CONFIG_MFD_RTSX_PCI) += rtsx_pci.o
diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index fc0c81e..197b273 100644
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c
@@ -119,6 +119,10 @@ static const struct mfd_cell cros_devs[] = {
.id = 2,
.of_compatible = "google,cros-ec-i2c-tunnel",
},
+ {
+ .name = "cros-ec-dev",
+ .id = 3,
+ },
};
int cros_ec_register(struct cros_ec_device *ec_dev)
diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
new file mode 100644
index 0000000..c18eb40
--- /dev/null
+++ b/drivers/mfd/cros_ec_dev.c
@@ -0,0 +1,355 @@
+/*
+ * 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/>.
+ */
+
+#define pr_fmt(fmt) "cros_ec_dev: " fmt
+
+#include <linux/compat.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/fs.h>
+#include <linux/mfd/cros_ec.h>
+#include <linux/mfd/cros_ec_commands.h>
+#include <linux/mfd/cros_ec_dev.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/printk.h>
+#include <linux/types.h>
+#include <linux/uaccess.h>
+
+/* Device variables */
+#define CROS_CLASS_NAME "chromeos"
+static struct cros_ec_device *ec;
+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 = NULL,
+ .outsize = 0,
+ .indata = (uint8_t *)&resp,
+ .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;
+ }
+ 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)
+{
+ 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)
+{
+ 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(void __user *argp)
+{
+ long ret;
+ struct cros_ec_command s_cmd;
+ uint8_t *user_indata;
+ uint8_t buf[EC_PROTO2_MAX_PARAM_SIZE];
+
+ if (copy_from_user(&s_cmd, argp, sizeof(s_cmd)))
+ return -EFAULT;
+ if (s_cmd.outsize &&
+ copy_from_user(&buf, (void __user *)s_cmd.outdata, sizeof(buf)))
+ return -EFAULT;
+
+ user_indata = s_cmd.indata;
+ s_cmd.indata = buf;
+ s_cmd.outdata = buf;
+ ret = cros_ec_cmd_xfer(ec, &s_cmd);
+ s_cmd.indata = user_indata;
+
+ /* Only copy data to userland if data was received. */
+ if (ret > 0 && s_cmd.insize) {
+ unsigned size = ret;
+
+ size = min(size, s_cmd.insize);
+ if (copy_to_user((void __user *)s_cmd.indata, buf, size))
+ return -EFAULT;
+ }
+ if (copy_to_user(argp, &s_cmd, sizeof(s_cmd)))
+ return -EFAULT;
+
+ return ret;
+}
+
+static long ec_device_ioctl_readmem(void __user *argp)
+{
+ struct cros_ec_readmem s_mem;
+ char buf[EC_MEMMAP_SIZE];
+ long num;
+
+ /* Not every platform supports direct reads */
+ if (!ec->cmd_readmem)
+ return -ENOTTY;
+
+ if (copy_from_user(&s_mem, argp, sizeof(s_mem)))
+ return -EFAULT;
+ num = ec->cmd_readmem(ec, s_mem.offset, s_mem.bytes, buf);
+ if (num <= 0)
+ return num;
+ if (copy_to_user((void __user *)s_mem.buffer, buf, num))
+ return -EFAULT;
+ return num;
+}
+
+static long ec_device_ioctl(struct file *filp, unsigned int cmd,
+ unsigned long arg)
+{
+ void __user *argp = (void __user *)arg;
+
+ if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC)
+ return -ENOTTY;
+
+ switch (cmd) {
+ case CROS_EC_DEV_IOCXCMD:
+ return ec_device_ioctl_xcmd(argp);
+ case CROS_EC_DEV_IOCRDMEM:
+ return ec_device_ioctl_readmem(argp);
+ }
+
+ return -ENOTTY;
+}
+
+#ifdef CONFIG_COMPAT
+struct compat_cros_ec_command {
+ uint32_t version;
+ uint32_t command;
+ compat_uptr_t outdata;
+ uint32_t outsize;
+ compat_uptr_t indata;
+ uint32_t insize;
+ uint32_t result;
+};
+
+struct compat_cros_ec_readmem {
+ uint32_t offset;
+ uint32_t bytes;
+ compat_uptr_t buffer;
+};
+
+#define CROS_EC_DEV_COMPAT_IOCXCMD _IOWR(':', 0, struct compat_cros_ec_command)
+#define CROS_EC_DEV_COMPAT_IOCRDMEM _IOWR(':', 1, struct compat_cros_ec_readmem)
+
+static long ec_device_compat_ioctl_readmem(void __user *argp)
+{
+ struct compat_cros_ec_readmem compat_s_mem;
+ char buf[EC_MEMMAP_SIZE];
+ long num;
+
+ /* Not every platform supports direct reads */
+ if (!ec->cmd_readmem)
+ return -ENOTTY;
+
+ if (copy_from_user(&compat_s_mem, argp, sizeof(compat_s_mem)))
+ return -EFAULT;
+
+ num = ec->cmd_readmem(ec, compat_s_mem.offset, compat_s_mem.bytes, buf);
+ if (num <= 0)
+ return num;
+
+ if (copy_to_user(compat_ptr(compat_s_mem.buffer), buf, num))
+ return -EFAULT;
+ return num;
+}
+
+static long ec_device_compat_ioctl_xcmd(void __user *argp)
+{
+ long ret;
+ struct cros_ec_command s_cmd;
+ struct compat_cros_ec_command compat_s_cmd;
+ uint8_t buf[EC_PROTO2_MAX_PARAM_SIZE];
+
+ if (copy_from_user(&compat_s_cmd, argp, sizeof(compat_s_cmd)))
+ return -EFAULT;
+
+ s_cmd.version = compat_s_cmd.version;
+ s_cmd.command = compat_s_cmd.command;
+ s_cmd.insize = compat_s_cmd.insize;
+ s_cmd.outsize = compat_s_cmd.outsize;
+
+ if (s_cmd.outsize &&
+ copy_from_user(&buf, compat_ptr(compat_s_cmd.outdata), sizeof(buf)))
+ return -EFAULT;
+
+ s_cmd.indata = buf;
+ s_cmd.outdata = buf;
+ ret = cros_ec_cmd_xfer(ec, &s_cmd);
+
+ compat_s_cmd.result = s_cmd.result;
+
+ /* Only copy data to userland if data was received. */
+ if (ret > 0 && s_cmd.insize) {
+ unsigned size = ret;
+
+ size = min(size, s_cmd.insize);
+ if (copy_to_user(compat_ptr(compat_s_cmd.indata), buf, size))
+ return -EFAULT;
+ }
+
+ if (copy_to_user(argp, &compat_s_cmd, sizeof(compat_s_cmd)))
+ return -EFAULT;
+
+ return ret;
+}
+
+static long ec_device_compat_ioctl(struct file *filp, unsigned int cmd,
+ unsigned long arg)
+{
+ void __user
+ *argp = (void __user *)arg;
+ switch (cmd) {
+ case CROS_EC_DEV_COMPAT_IOCXCMD:
+ return ec_device_compat_ioctl_xcmd(argp);
+ case CROS_EC_DEV_COMPAT_IOCRDMEM:
+ return ec_device_compat_ioctl_readmem(argp);
+ }
+ return -ENOTTY;
+}
+#endif /* CONFIG_COMPAT */
+
+
+/* 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,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = ec_device_compat_ioctl,
+#endif
+};
+
+static int ec_device_probe(struct platform_device *pdev)
+{
+ int retval = -ENOTTY;
+
+ ec = dev_get_drvdata(pdev->dev.parent);
+
+ cros_class = class_create(THIS_MODULE, CROS_CLASS_NAME);
+ if (IS_ERR(cros_class)) {
+ pr_err("failed to register device class\n");
+ retval = PTR_ERR(cros_class);
+ goto failed_class;
+ }
+
+ /* Let the kernel pick the major num for us */
+ ec_major = register_chrdev(0, CROS_EC_DEV_NAME, &fops);
+ if (ec_major < 0) {
+ pr_err("failed to register device\n");
+ retval = ec_major;
+ goto failed_chrdevreg;
+ }
+
+ /* Instantiate it */
+ ec->vdev = device_create(cros_class, NULL, MKDEV(ec_major, 0),
+ NULL, CROS_EC_DEV_NAME);
+ if (IS_ERR(ec->vdev)) {
+ pr_err("failed to create device\n");
+ retval = PTR_ERR(ec->vdev);
+ goto failed_devreg;
+ }
+
+ return 0;
+
+failed_devreg:
+ unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
+failed_chrdevreg:
+ class_destroy(cros_class);
+failed_class:
+ return retval;
+}
+
+static int ec_device_remove(struct platform_device *pdev)
+{
+ device_destroy(cros_class, MKDEV(ec_major, 0));
+ unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
+ class_destroy(cros_class);
+ return 0;
+}
+
+static struct platform_driver cros_ec_dev_driver = {
+ .driver = {
+ .name = "cros-ec-dev",
+ .owner = THIS_MODULE,
+ },
+ .probe = ec_device_probe,
+ .remove = ec_device_remove,
+};
+
+module_platform_driver(cros_ec_dev_driver);
+
+MODULE_AUTHOR("Bill Richardson <wfrichar@...omium.org>");
+MODULE_DESCRIPTION("Userspace interface to the Chrome OS Embedded Controller");
+MODULE_VERSION("1.0");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 0e166b9..b1cb934 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -59,9 +59,16 @@ 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
* @was_wake_device: true if this device was set to wake the system from
* sleep at the last suspend
+ * @cmd_read_mem: 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 +97,11 @@ struct cros_ec_device {
const char *ec_name;
const char *phys_name;
struct device *dev;
+ struct device *vdev;
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;
diff --git a/include/linux/mfd/cros_ec_dev.h b/include/linux/mfd/cros_ec_dev.h
new file mode 100644
index 0000000..465e926
--- /dev/null
+++ b/include/linux/mfd/cros_ec_dev.h
@@ -0,0 +1,47 @@
+/*
+ * cros_ec_dev - expose the Chrome OS Embedded Controller to userspace
+ *
+ * Copyright (C) 2013 The Chromium OS Authors
+ *
+ * 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;
+ char *buffer;
+};
+
+#define CROS_EC_DEV_IOC ':'
+#define CROS_EC_DEV_IOCXCMD _IOWR(':', 0, struct cros_ec_command)
+#define CROS_EC_DEV_IOCRDMEM _IOWR(':', 1, struct cros_ec_readmem)
+
+#endif /* _CROS_EC_DEV_H_ */
--
2.1.0
--
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