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>

1 files changed, 38 insertions, 6 deletions

diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 92e13aaa450c..da72671a42fa 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -17,10 +17,14 @@
 #define __LINUX_MFD_CROS_EC_H
 
 #include <linux/cdev.h>
+#include <linux/device.h>
 #include <linux/notifier.h>
 #include <linux/mfd/cros_ec_commands.h>
 #include <linux/mutex.h>
 
+#define CROS_EC_DEV_NAME "cros_ec"
+#define CROS_EC_DEV_PD_NAME "cros_pd"
+
 /*
  * The EC is unresponsive for a time after a reboot command.  Add a
  * simple delay to make sure that the bus stays locked.
@@ -71,11 +75,8 @@ struct cros_ec_command {
 /**
  * struct cros_ec_device - Information about a ChromeOS EC device
  *
- * @ec_name: name of EC device (e.g. 'chromeos-ec')
  * @phys_name: name of physical comms layer (e.g. 'i2c-4')
  * @dev: Device pointer for physical comms device
- * @vdev: Device pointer for virtual comms device
- * @cdev: Character device structure for virtual comms device
  * @was_wake_device: true if this device was set to wake the system from
  * sleep at the last suspend
  * @cmd_readmem: direct read of the EC memory-mapped region, if supported
@@ -87,6 +88,7 @@ struct cros_ec_command {
  *
  * @priv: Private data
  * @irq: Interrupt to use
+ * @id: Device id
  * @din: input buffer (for data from EC)
  * @dout: output buffer (for data to EC)
  * \note
@@ -109,11 +111,8 @@ struct cros_ec_command {
 struct cros_ec_device {
 
 	/* These are used by other drivers that want to talk to the EC */
-	const char *ec_name;
 	const char *phys_name;
 	struct device *dev;
-	struct device *vdev;
-	struct cdev cdev;
 	bool was_wake_device;
 	struct class *cros_class;
 	int (*cmd_readmem)(struct cros_ec_device *ec, unsigned int offset,
@@ -138,6 +137,35 @@ struct cros_ec_device {
 	struct mutex lock;
 };
 
+/* struct cros_ec_platform - ChromeOS EC platform information
+ *
+ * @ec_name: name of EC device (e.g. 'cros-ec', 'cros-pd', ...)
+ * used in /dev/ and sysfs.
+ * @cmd_offset: offset to apply for each command. Set when
+ * registering a devicde behind another one.
+ */
+struct cros_ec_platform {
+	const char *ec_name;
+	u16 cmd_offset;
+};
+
+/*
+ * 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
+ * @cmd_offset: offset to apply for each command.
+ */
+struct cros_ec_dev {
+	struct device class_dev;
+	struct cdev cdev;
+	struct cros_ec_device *ec_dev;
+	struct device *dev;
+	u16 cmd_offset;
+};
+
 /**
  * cros_ec_suspend - Handle a suspend operation for the ChromeOS EC device
  *
@@ -224,4 +252,8 @@ int cros_ec_register(struct cros_ec_device *ec_dev);
  */
 int cros_ec_query_all(struct cros_ec_device *ec_dev);
 
+/* sysfs stuff */
+extern struct attribute_group cros_ec_attr_group;
+extern struct attribute_group cros_ec_lightbar_attr_group;
+
 #endif /* __LINUX_MFD_CROS_EC_H */