mfd: cros_ec: Use a zero-length array for command data

[cascardo/linux.git] / include / linux / mfd / cros_ec.h

diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index fcbe9d1..7eee38a 100644 (file)
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -16,6 +16,7 @@
 #ifndef __LINUX_MFD_CROS_EC_H
 #define __LINUX_MFD_CROS_EC_H
 
+#include <linux/cdev.h>
 #include <linux/notifier.h>
 #include <linux/mfd/cros_ec_commands.h>
 #include <linux/mutex.h>
@@ -38,20 +39,18 @@ enum {
 /*
  * @version: Command version number (often 0)
  * @command: Command to send (EC_CMD_...)
- * @outdata: Outgoing data to EC
  * @outsize: Outgoing length in bytes
- * @indata: Where to put the incoming data from EC
  * @insize: Max number of bytes to accept from EC
  * @result: EC's response to the command (separate from communication failure)
+ * @data: Where to put the incoming data from EC and outgoing data to EC
  */
 struct cros_ec_command {
        uint32_t version;
        uint32_t command;
-       uint8_t *outdata;
        uint32_t outsize;
-       uint8_t *indata;
        uint32_t insize;
        uint32_t result;
+       uint8_t data[0];
 };
 
 /**
@@ -59,13 +58,17 @@ 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
+ * @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_xfer: send command to EC and get response
- *     Returns the number of bytes received if the communication succeeded, but
- *     that doesn't mean the EC was happy with the command. The caller
- *     should check msg.result for the EC's result code.
+ * @cmd_readmem: 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
@@ -80,8 +83,11 @@ struct cros_ec_command {
  * to using dword.
  * @din_size: size of din buffer to allocate (zero to use static din)
  * @dout_size: size of dout buffer to allocate (zero to use static dout)
- * @parent: pointer to parent device (e.g. i2c or spi device)
  * @wake_enabled: true if this device can wake the system from sleep
+ * @cmd_xfer: send command to EC and get response
+ *     Returns the number of bytes received if the communication succeeded, but
+ *     that doesn't mean the EC was happy with the command. The caller
+ *     should check msg.result for the EC's result code.
  * @lock: one transaction at a time
  */
 struct cros_ec_device {
@@ -90,10 +96,12 @@ struct cros_ec_device {
        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_xfer)(struct cros_ec_device *ec,
-                       struct cros_ec_command *msg);
+       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;
@@ -102,8 +110,9 @@ struct cros_ec_device {
        uint8_t *dout;
        int din_size;
        int dout_size;
-       struct device *parent;
        bool wake_enabled;
+       int (*cmd_xfer)(struct cros_ec_device *ec,
+                       struct cros_ec_command *msg);
        struct mutex lock;
 };
 
@@ -152,6 +161,18 @@ int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
 int cros_ec_check_result(struct cros_ec_device *ec_dev,
                         struct cros_ec_command *msg);
 
+/**
+ * cros_ec_cmd_xfer - Send a command to the ChromeOS EC
+ *
+ * Call this to send a command to the ChromeOS EC.  This should be used
+ * instead of calling the EC's cmd_xfer() callback directly.
+ *
+ * @ec_dev: EC device
+ * @msg: Message to write
+ */
+int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
+                    struct cros_ec_command *msg);
+
 /**
  * cros_ec_remove - Remove a ChromeOS EC
  *