mfd: cros_ec: Support multiple EC in a system
Chromebooks can have more than one Embedded Controller so the
cros_ec device id has to be incremented for each EC registered.
Add a new structure to represent multiple EC as different char
devices (e.g: /dev/cros_ec, /dev/cros_pd). It connects to
cros_ec_device and allows sysfs inferface for cros_pd.
Also reduce number of allocated objects, make chromeos sysfs
class object a static and add refcounting to prevent object
deletion while command is in progress.
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Dmitry Torokhov <dtor@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
Acked-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
index e91ced1..e8fcdc2 100644
--- a/drivers/platform/chrome/cros_ec_dev.c
+++ b/drivers/platform/chrome/cros_ec_dev.c
@@ -27,11 +27,22 @@
/* Device variables */
#define CROS_MAX_DEV 128
-static struct class *cros_class;
static int ec_major;
+static const struct attribute_group *cros_ec_groups[] = {
+ &cros_ec_attr_group,
+ &cros_ec_lightbar_attr_group,
+ NULL,
+};
+
+static struct class cros_class = {
+ .owner = THIS_MODULE,
+ .name = "chromeos",
+ .dev_groups = cros_ec_groups,
+};
+
/* Basic communication */
-static int ec_get_version(struct cros_ec_device *ec, char *str, int maxlen)
+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[] = {
@@ -45,11 +56,11 @@
return -ENOMEM;
msg->version = 0;
- msg->command = EC_CMD_GET_VERSION;
+ msg->command = EC_CMD_GET_VERSION + ec->cmd_offset;
msg->insize = sizeof(*resp);
msg->outsize = 0;
- ret = cros_ec_cmd_xfer(ec, msg);
+ ret = cros_ec_cmd_xfer(ec->ec_dev, msg);
if (ret < 0)
goto exit;
@@ -78,8 +89,10 @@
/* 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);
+ 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;
}
@@ -91,7 +104,7 @@
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;
+ struct cros_ec_dev *ec = filp->private_data;
char msg[sizeof(struct ec_response_get_version) +
sizeof(CROS_EC_DEV_VERSION)];
size_t count;
@@ -114,7 +127,7 @@
}
/* Ioctls */
-static long ec_device_ioctl_xcmd(struct cros_ec_device *ec, void __user *arg)
+static long ec_device_ioctl_xcmd(struct cros_ec_dev *ec, void __user *arg)
{
long ret;
struct cros_ec_command u_cmd;
@@ -133,7 +146,8 @@
goto exit;
}
- ret = cros_ec_cmd_xfer(ec, s_cmd);
+ 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;
@@ -145,19 +159,21 @@
return ret;
}
-static long ec_device_ioctl_readmem(struct cros_ec_device *ec, void __user *arg)
+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->cmd_readmem)
+ if (!ec_dev->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);
+ num = ec_dev->cmd_readmem(ec_dev, s_mem.offset, s_mem.bytes,
+ s_mem.buffer);
if (num <= 0)
return num;
@@ -170,7 +186,7 @@
static long ec_device_ioctl(struct file *filp, unsigned int cmd,
unsigned long arg)
{
- struct cros_ec_device *ec = filp->private_data;
+ struct cros_ec_dev *ec = filp->private_data;
if (_IOC_TYPE(cmd) != CROS_EC_DEV_IOC)
return -ENOTTY;
@@ -193,45 +209,81 @@
.unlocked_ioctl = ec_device_ioctl,
};
+static void __remove(struct device *dev)
+{
+ struct cros_ec_dev *ec = container_of(dev, struct cros_ec_dev,
+ class_dev);
+ kfree(ec);
+}
+
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);
+ int retval = -ENOMEM;
+ struct device *dev = &pdev->dev;
+ struct cros_ec_platform *ec_platform = dev_get_platdata(dev);
+ dev_t devno = MKDEV(ec_major, pdev->id);
+ struct cros_ec_dev *ec = kzalloc(sizeof(*ec), GFP_KERNEL);
- /* Instantiate it (and remember the EC) */
+ if (!ec)
+ return retval;
+
+ dev_set_drvdata(dev, ec);
+ ec->ec_dev = dev_get_drvdata(dev->parent);
+ ec->dev = dev;
+ ec->cmd_offset = ec_platform->cmd_offset;
+ device_initialize(&ec->class_dev);
cdev_init(&ec->cdev, &fops);
+ /*
+ * Add the character device
+ * Link cdev to the class device to be sure device is not used
+ * before unbinding it.
+ */
+ ec->cdev.kobj.parent = &ec->class_dev.kobj;
retval = cdev_add(&ec->cdev, devno, 1);
if (retval) {
- dev_err(&pdev->dev, ": failed to add character device\n");
- return retval;
+ dev_err(dev, ": failed to add character device\n");
+ goto cdev_add_failed;
}
- 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;
+ /*
+ * Add the class device
+ * Link to the character device for creating the /dev entry
+ * in devtmpfs.
+ */
+ ec->class_dev.devt = ec->cdev.dev;
+ ec->class_dev.class = &cros_class;
+ ec->class_dev.parent = dev;
+ ec->class_dev.release = __remove;
+
+ retval = dev_set_name(&ec->class_dev, "%s", ec_platform->ec_name);
+ if (retval) {
+ dev_err(dev, "dev_set_name failed => %d\n", retval);
+ goto set_named_failed;
}
- /* Initialize extra interfaces */
- ec_dev_sysfs_init(ec);
- ec_dev_lightbar_init(ec);
+ retval = device_add(&ec->class_dev);
+ if (retval) {
+ dev_err(dev, "device_register failed => %d\n", retval);
+ goto dev_reg_failed;
+ }
return 0;
+
+dev_reg_failed:
+set_named_failed:
+ dev_set_drvdata(dev, NULL);
+ cdev_del(&ec->cdev);
+cdev_add_failed:
+ kfree(ec);
+ return retval;
}
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));
+ struct cros_ec_dev *ec = dev_get_drvdata(&pdev->dev);
cdev_del(&ec->cdev);
+ device_unregister(&ec->class_dev);
return 0;
}
@@ -248,10 +300,10 @@
int ret;
dev_t dev = 0;
- cros_class = class_create(THIS_MODULE, "chromeos");
- if (IS_ERR(cros_class)) {
+ ret = class_register(&cros_class);
+ if (ret) {
pr_err(CROS_EC_DEV_NAME ": failed to register device class\n");
- return PTR_ERR(cros_class);
+ return ret;
}
/* Get a range of minor numbers (starting with 0) to work with */
@@ -273,7 +325,7 @@
failed_devreg:
unregister_chrdev_region(MKDEV(ec_major, 0), CROS_MAX_DEV);
failed_chrdevreg:
- class_destroy(cros_class);
+ class_unregister(&cros_class);
return ret;
}
@@ -281,7 +333,7 @@
{
platform_driver_unregister(&cros_ec_dev_driver);
unregister_chrdev(ec_major, CROS_EC_DEV_NAME);
- class_destroy(cros_class);
+ class_unregister(&cros_class);
}
module_init(cros_ec_dev_init);