mfd: cros_ec: Switch to use the new cros-ec-chardev driver

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>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

2 files changed, 6 insertions, 216 deletions

diff --git a/drivers/mfd/cros_ec_dev.c b/drivers/mfd/cros_ec_dev.c
index 4c96445b1bf5..0c1c0ce3453e 100644
--- a/drivers/mfd/cros_ec_dev.c
+++ b/drivers/mfd/cros_ec_dev.c
@@ -5,76 +5,23 @@
  * 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>
 #include <linux/module.h>
 #include <linux/mod_devicetable.h>
-#include <linux/platform_data/cros_ec_chardev.h>
 #include <linux/of_platform.h>
 #include <linux/platform_device.h>
-#include <linux/pm.h>
+#include <linux/platform_data/cros_ec_chardev.h>
 #include <linux/slab.h>
-#include <linux/uaccess.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 +57,6 @@ 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 +264,7 @@ 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 +292,6 @@ 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 +338,7 @@ 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 +349,10 @@ 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 +396,6 @@ 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 +429,6 @@ 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 +451,6 @@ 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 +458,6 @@ 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 +467,6 @@ 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 +474,6 @@ failed_chrdevreg:
 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;