Input: add ps2_drain() to libps2 to allow reading and discarding

       given number of bytes from device. Change ps2_command to
       allow using 0 as command ID and actually pass it to the
       device instead of working as a drain.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

diff --git a/drivers/input/mouse/alps.c b/drivers/input/mouse/alps.c
index 2679a165d399118fd8224cd0cd5c23877b6dc471..ffdc823131928ef229143b1fafc6dccdbf1a2549 100644 (file)
--- a/drivers/input/mouse/alps.c
+++ b/drivers/input/mouse/alps.c
@@ -270,7 +270,6 @@ static struct alps_model_info *alps_get_model(struct psmouse *psmouse, int *vers
 static int alps_passthrough_mode(struct psmouse *psmouse, int enable)
 {
        struct ps2dev *ps2dev = &psmouse->ps2dev;
-       unsigned char param[3];
        int cmd = enable ? PSMOUSE_CMD_SETSCALE21 : PSMOUSE_CMD_SETSCALE11;
 
        if (ps2_command(ps2dev, NULL, cmd) ||
@@ -280,7 +279,7 @@ static int alps_passthrough_mode(struct psmouse *psmouse, int enable)
                return -1;
 
        /* we may get 3 more bytes, just ignore them */
-       ps2_command(ps2dev, param, 0x0300);
+       ps2_drain(ps2dev, 3, 100);
 
        return 0;
 }

diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c
index c978657068c55b6ade7644b65e9089ae272810bc..92b92ee0379177d291e01c829f94a11e6f34cdf8 100644 (file)
--- a/drivers/input/serio/libps2.c
+++ b/drivers/input/serio/libps2.c
@@ -29,6 +29,7 @@ MODULE_LICENSE("GPL");
 
 EXPORT_SYMBOL(ps2_init);
 EXPORT_SYMBOL(ps2_sendbyte);
+EXPORT_SYMBOL(ps2_drain);
 EXPORT_SYMBOL(ps2_command);
 EXPORT_SYMBOL(ps2_schedule_command);
 EXPORT_SYMBOL(ps2_handle_ack);
@@ -45,11 +46,11 @@ struct ps2work {
 
 
 /*
- * ps2_sendbyte() sends a byte to the mouse, and waits for acknowledge.
- * It doesn't handle retransmission, though it could - because when there would
- * be need for retransmissions, the mouse has to be replaced anyway.
+ * ps2_sendbyte() sends a byte to the device and waits for acknowledge.
+ * It doesn't handle retransmission, though it could - because if there
+ * is a need for retransmissions device has to be replaced anyway.
  *
- * ps2_sendbyte() can only be called from a process context
+ * ps2_sendbyte() can only be called from a process context.
  */
 
 int ps2_sendbyte(struct ps2dev *ps2dev, unsigned char byte, int timeout)
@@ -71,6 +72,31 @@ int ps2_sendbyte(struct ps2dev *ps2dev, unsigned char byte, int timeout)
        return -ps2dev->nak;
 }
 
+/*
+ * ps2_drain() waits for device to transmit requested number of bytes
+ * and discards them.
+ */
+
+void ps2_drain(struct ps2dev *ps2dev, int maxbytes, int timeout)
+{
+       if (maxbytes > sizeof(ps2dev->cmdbuf)) {
+               WARN_ON(1);
+               maxbytes = sizeof(ps2dev->cmdbuf);
+       }
+
+       down(&ps2dev->cmd_sem);
+
+       serio_pause_rx(ps2dev->serio);
+       ps2dev->flags = PS2_FLAG_CMD;
+       ps2dev->cmdcnt = maxbytes;
+       serio_continue_rx(ps2dev->serio);
+
+       wait_event_timeout(ps2dev->wait,
+                          !(ps2dev->flags & PS2_FLAG_CMD),
+                          msecs_to_jiffies(timeout));
+       up(&ps2dev->cmd_sem);
+}
+
 /*
  * ps2_command() sends a command and its parameters to the mouse,
  * then waits for the response and puts it in the param array.
@@ -86,6 +112,11 @@ int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
        int rc = -1;
        int i;
 
+       if (receive > sizeof(ps2dev->cmdbuf)) {
+               WARN_ON(1);
+               return -1;
+       }
+
        down(&ps2dev->cmd_sem);
 
        serio_pause_rx(ps2dev->serio);
@@ -101,10 +132,9 @@ int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
         * ACKing the reset command, and so it can take a long
         * time before the ACK arrrives.
         */
-       if (command & 0xff)
-               if (ps2_sendbyte(ps2dev, command & 0xff,
-                       command == PS2_CMD_RESET_BAT ? 1000 : 200))
-                       goto out;
+       if (ps2_sendbyte(ps2dev, command & 0xff,
+                        command == PS2_CMD_RESET_BAT ? 1000 : 200))
+               goto out;
 
        for (i = 0; i < send; i++)
                if (ps2_sendbyte(ps2dev, param[i], 200))

diff --git a/include/linux/libps2.h b/include/linux/libps2.h
index 923bdbc6d9e40da0b83a659f4e743f03a18ab851..a710bddda4ebaade343bd925bf7f9c7fb9fc20a5 100644 (file)
--- a/include/linux/libps2.h
+++ b/include/linux/libps2.h
@@ -41,6 +41,7 @@ struct ps2dev {
 
 void ps2_init(struct ps2dev *ps2dev, struct serio *serio);
 int ps2_sendbyte(struct ps2dev *ps2dev, unsigned char byte, int timeout);
+void ps2_drain(struct ps2dev *ps2dev, int maxbytes, int timeout);
 int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command);
 int ps2_schedule_command(struct ps2dev *ps2dev, unsigned char *param, int command);
 int ps2_handle_ack(struct ps2dev *ps2dev, unsigned char data);