[PATCH v5 04/11] mfd: cros_ec: Switch to use the new cros-ec-chardev driver

Enric Balletbo i Serra
2019-07-22T13:33:53Z

With the purpose of remove the things that far extends the bounds of
what a MFD was designed to do, instantiate the new platform misc
cros-ec-chardev driver and get rid of all the unneeded code. After this
patch the misc chardev driver is a sub-device of the MFD, and all the
new file operations should be implemented there.

Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Gwendal Grignou <gwendal@chromium.org>
Tested-by: Gwendal Grignou <gwendal@chromium.org>
---

Changes in v5: None
Changes in v4: None
Changes in v3: None
Changes in v2: None

drivers/mfd/cros_ec_dev.c | 219 +-----------------------------------
include/linux/mfd/cros_ec.h | 2 -
2 files changed, 5 insertions(+), 216 deletions(-)

diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index f923617f0d5d..48a593e7ed02 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -5,7 +5,6 @@
* Copyright (C) 2014 Google, Inc.
*/

-#include <linux/fs.h>
#include <linux/mfd/core.h>
#include <linux/mfd/cros_ec.h>
#include <linux/mfd/cros_ec_commands.h>
@@ -13,68 +12,15 @@
#include <linux/mod_devicetable.h>
#include <linux/of_platform.h>
#include <linux/platform_device.h>
-#include <linux/pm.h>
#include <linux/slab.h>
-#include <linux/uaccess.h>
-
-#include <uapi/linux/cros_ec_chardev.h>

#define DRV_NAME "cros-ec-dev"

-/* Device variables */
-#define CROS_MAX_DEV 128
-static int ec_major;
-
static struct class cros_class = {
.owner = THIS_MODULE,
.name = "chromeos",
};

-/* Basic communication */
-static int ec_get_version(struct cros_ec_dev *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;
- int ret;
-
- msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
- if (!msg)
- return -ENOMEM;
-
- msg->version = 0;
- msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
- msg->insize = sizeof(*resp);
- msg->outsize = 0;
-
- ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
- if (ret < 0)
- goto exit;
-
- if (msg->result != EC_RES_SUCCESS) {
- snprintf(str, maxlen,
- "%s\nUnknown EC version: EC returned %d\n",
- CROS_EC_DEV_VERSION, msg->result);
- ret = -EINVAL;
- goto exit;
- }
-
- resp = (struct ec_response_get_version *)msg->data;
- 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]);
-
- ret = 0;
-exit:
- kfree(msg);
- return ret;
-}
-
static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
{
struct cros_ec_command *msg;
@@ -110,142 +56,6 @@ static int cros_ec_check_features(struct cros_ec_dev *ec, int feature)
return ec->features[feature / 32] & EC_FEATURE_MASK_0(feature);
}

-/* Device file ops */
-static int ec_device_open(struct inode *inode, struct file *filp)
-{
- struct cros_ec_dev *ec = container_of(inode->i_cdev,
- struct cros_ec_dev, cdev);
- filp->private_data = ec;
- nonseekable_open(inode, 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)
-{
- struct cros_ec_dev *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_dev *ec, void __user *arg)
-{
- long ret;
- struct cros_ec_command u_cmd;
- struct cros_ec_command *s_cmd;
-
- if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
- return -EFAULT;
-
- if ((u_cmd.outsize > EC_MAX_MSG_BYTES) ||
- (u_cmd.insize > EC_MAX_MSG_BYTES))
- return -EINVAL;
-
- s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
- GFP_KERNEL);
- if (!s_cmd)
- return -ENOMEM;
-
- if (copy_from_user(s_cmd, arg, sizeof(*s_cmd) + u_cmd.outsize)) {
- ret = -EFAULT;
- goto exit;
- }
-
- if (u_cmd.outsize != s_cmd->outsize ||
- u_cmd.insize != s_cmd->insize) {
- ret = -EINVAL;
- goto exit;
- }
-
- s_cmd->command += ec->cmd_offset;
- ret = cros_ec_cmd_xfer(ec->ec_dev, s_cmd);
- /* Only copy data to userland if data was received. */
- if (ret < 0)
- goto exit;
-
- if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + s_cmd->insize))
- ret = -EFAULT;
-exit:
- kfree(s_cmd);
- return ret;
-}
-
-static long ec_device_ioctl_readmem(struct cros_ec_dev *ec, void __user *arg)
-{
- struct cros_ec_device *ec_dev = ec->ec_dev;
- struct cros_ec_readmem s_mem = { };
- long num;
-
- /* Not every platform supports direct reads */
- if (!ec_dev->cmd_readmem)
- return -ENOTTY;
-
- if (copy_from_user(&s_mem, arg, sizeof(s_mem)))
- return -EFAULT;
-
- num = ec_dev->cmd_readmem(ec_dev, 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 num;
-}
-
-static long ec_device_ioctl(struct file *filp, unsigned int cmd,
- unsigned long arg)
-{
- struct cros_ec_dev *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,
-#ifdef CONFIG_COMPAT
- .compat_ioctl = ec_device_ioctl,
-#endif
-};
-
static void cros_ec_class_release(struct device *dev)
{
kfree(to_cros_ec_dev(dev));
@@ -453,6 +263,7 @@ static const struct mfd_cell cros_usbpd_charger_cells[] = {
};

static const struct mfd_cell cros_ec_platform_cells[] = {
+ { .name = "cros-ec-chardev" },
{ .name = "cros-ec-debugfs" },
{ .name = "cros-ec-lightbar" },
{ .name = "cros-ec-sysfs" },
@@ -480,7 +291,6 @@ static int ec_device_probe(struct platform_device *pdev)
ec->features[0] = -1U; /* Not cached yet */
ec->features[1] = -1U; /* Not cached yet */
device_initialize(&ec->class_dev);
- cdev_init(&ec->cdev, &fops);

/* Check whether this is actually a Fingerprint MCU rather than an EC */
if (cros_ec_check_features(ec, EC_FEATURE_FINGERPRINT)) {
@@ -527,10 +337,7 @@ static int ec_device_probe(struct platform_device *pdev)

/*
* Add the class device
- * Link to the character device for creating the /dev entry
- * in devtmpfs.
*/
- ec->class_dev.devt = MKDEV(ec_major, pdev->id);
ec->class_dev.class = &cros_class;
ec->class_dev.parent = dev;
ec->class_dev.release = cros_ec_class_release;
@@ -541,6 +348,10 @@ static int ec_device_probe(struct platform_device *pdev)
goto failed;
}

+ retval = device_add(&ec->class_dev);
+ if (retval)
+ goto failed;
+
/* check whether this EC is a sensor hub. */
if (cros_ec_check_features(ec, EC_FEATURE_MOTION_SENSE))
cros_ec_sensors_register(ec);
@@ -584,13 +395,6 @@ static int ec_device_probe(struct platform_device *pdev)
retval);
}

- /* We can now add the sysfs class, we know which parameter to show */
- retval = cdev_device_add(&ec->cdev, &ec->class_dev);
- if (retval) {
- dev_err(dev, "cdev_device_add failed => %d\n", retval);
- goto failed;
- }
-
retval = mfd_add_devices(ec->dev, PLATFORM_DEVID_AUTO,
cros_ec_platform_cells,
ARRAY_SIZE(cros_ec_platform_cells),
@@ -624,7 +428,6 @@ static int ec_device_remove(struct platform_device *pdev)
struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);

mfd_remove_devices(ec->dev);
- cdev_del(&ec->cdev);
device_unregister(&ec->class_dev);
return 0;
}
@@ -647,7 +450,6 @@ static struct platform_driver cros_ec_dev_driver = {
static int __init cros_ec_dev_init(void)
{
int ret;
- dev_t dev = 0;

ret = class_register(&cros_class);
if (ret) {
@@ -655,14 +457,6 @@ static int __init cros_ec_dev_init(void)
return ret;
}

- /* 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) {
@@ -672,8 +466,6 @@ static int __init cros_ec_dev_init(void)
return 0;

failed_devreg:
- unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV);
-failed_chrdevreg:
class_unregister(&cros_class);
return ret;
}
@@ -681,7 +473,6 @@ static int __init cros_ec_dev_init(void)
static void __exit cros_ec_dev_exit(void)
{
platform_driver_unregister(&cros_ec_dev_driver);
- unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
class_unregister(&cros_class);
}

diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index bcccda0257ff..569428ad1cb1 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -192,7 +192,6 @@ struct cros_ec_debugfs;
/**
* struct cros_ec_dev - ChromeOS EC device entry point.
* @class_dev: Device structure used in sysfs.
- * @cdev: Character device structure in /dev.
* @ec_dev: cros_ec_device structure to talk to the physical device.
* @dev: Pointer to the platform device.
* @debug_info: cros_ec_debugfs structure for debugging information.
@@ -202,7 +201,6 @@ struct cros_ec_debugfs;
*/
struct cros_ec_dev {
struct device class_dev;
- struct cdev cdev;
struct cros_ec_device *ec_dev;
struct device *dev;
struct cros_ec_debugfs *debug_info;
--
2.20.1