staging: nvec: Rewrite the interrupt handler

Rewrite the interrupt handler to use a state machine similar to
that found in the various kernels for the Advent Vega. This also
changes the code to use the new functions introduced in the
previous commits.

This also merges the rewrite sent in August 2011 by Marc
Dietrich, and thus also includes code by him. His original
patch can be found on the mailing list.
Signed-off-by: Julian Andres Klode <jak@jak-linux.org>
Acked-by: Marc Dietrich <marvin24@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/nvec/nvec.h

@@ -23,39 +23,36 @@
 /* NVEC_POOL_SIZE - Size of the pool in &struct nvec_msg */
 #define NVEC_POOL_SIZE	64
 
-typedef enum {
+/*
+ * NVEC_MSG_SIZE - Maximum size of the data field of &struct nvec_msg.
+ *
+ * A message must store up to a SMBus block operation which consists of
+ * one command byte, one count byte, and up to 32 payload bytes = 34
+ * byte.
+ */
+#define NVEC_MSG_SIZE	34
+
+enum {
 	NVEC_2BYTES,
 	NVEC_3BYTES,
-	NVEC_VAR_SIZE
-} nvec_size;
-
-typedef enum {
-	NOT_REALLY,
-	YES,
-	NOT_AT_ALL,
-} how_care;
+	NVEC_VAR_SIZE,
+};
 
-typedef enum {
+enum {
 	NVEC_SYS = 1,
 	NVEC_BAT,
 	NVEC_KBD = 5,
 	NVEC_PS2,
 	NVEC_CNTL,
 	NVEC_KB_EVT = 0x80,
-	NVEC_PS2_EVT
-} nvec_event;
-
-typedef enum {
-	NVEC_WAIT,
-	NVEC_READ,
-	NVEC_WRITE
-} nvec_state;
+	NVEC_PS2_EVT,
+};
 
 struct nvec_msg {
-	unsigned char *data;
+	struct list_head node;
+	unsigned char data[NVEC_MSG_SIZE];
 	unsigned short size;
 	unsigned short pos;
-	struct list_head node;
 	atomic_t used;
 };
 
@@ -77,24 +74,35 @@ struct nvec_chip {
 	int i2c_addr;
 	void __iomem *base;
 	struct clk *i2c_clk;
-	nvec_state state;
 	struct atomic_notifier_head notifier_list;
 	struct list_head rx_data, tx_data;
 	struct notifier_block nvec_status_notifier;
 	struct work_struct rx_work, tx_work;
-	struct nvec_msg *rx, *tx;
+	struct workqueue_struct *wq;
 	struct nvec_msg msg_pool[NVEC_POOL_SIZE];
+	struct nvec_msg *rx;
+
+	struct nvec_msg *tx;
+	struct nvec_msg tx_scratch;
+	struct completion ec_transfer;
+
+	spinlock_t tx_lock, rx_lock;
 
 	/* sync write stuff */
-	struct semaphore sync_write_mutex;
+	struct mutex sync_write_mutex;
 	struct completion sync_write;
 	u16 sync_write_pending;
 	struct nvec_msg *last_sync_msg;
+
+	int state;
 };
 
 extern void nvec_write_async(struct nvec_chip *nvec, const unsigned char *data,
 			     short size);
 
+extern struct nvec_msg *nvec_write_sync(struct nvec_chip *nvec,
+					const unsigned char *data, short size);
+
 extern int nvec_register_notifier(struct nvec_chip *nvec,
 				  struct notifier_block *nb,
 				  unsigned int events);
@@ -103,10 +111,6 @@ extern int nvec_unregister_notifier(struct device *dev,
 				    struct notifier_block *nb,
 				    unsigned int events);
 
-const char *nvec_send_msg(unsigned char *src, unsigned char *dst_size,
-			  how_care care_resp,
-			  void (*rt_handler) (unsigned char *data));
-
 #define I2C_CNFG			0x00
 #define I2C_CNFG_PACKET_MODE_EN		(1<<10)
 #define I2C_CNFG_NEW_MASTER_SFM		(1<<11)

drivers/staging/nvec/nvec_kbd.c

@@ -41,7 +41,7 @@ static int nvec_keys_notifier(struct notifier_block *nb,
 	unsigned char *msg = (unsigned char *)data;
 
 	if (event_type == NVEC_KB_EVT) {
-		nvec_size _size = (msg[0] & (3 << 5)) >> 5;
+		int _size = (msg[0] & (3 << 5)) >> 5;
 
 /* power on/off button */
 		if (_size == NVEC_VAR_SIZE)