Input: i8042 - allow installing platform filters for incoming data

[safe/jmp/linux-2.6] / drivers / input / serio / i8042.c

diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index 634da68..d84a36e 100644 (file)
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -126,6 +126,8 @@ static unsigned char i8042_suppress_kbd_ack;
 static struct platform_device *i8042_platform_device;
 
 static irqreturn_t i8042_interrupt(int irq, void *dev_id);
+static bool (*i8042_platform_filter)(unsigned char data, unsigned char str,
+                                    struct serio *serio);
 
 void i8042_lock_chip(void)
 {
@@ -139,6 +141,48 @@ void i8042_unlock_chip(void)
 }
 EXPORT_SYMBOL(i8042_unlock_chip);
 
+int i8042_install_filter(bool (*filter)(unsigned char data, unsigned char str,
+                                       struct serio *serio))
+{
+       unsigned long flags;
+       int ret = 0;
+
+       spin_lock_irqsave(&i8042_lock, flags);
+
+       if (i8042_platform_filter) {
+               ret = -EBUSY;
+               goto out;
+       }
+
+       i8042_platform_filter = filter;
+
+out:
+       spin_unlock_irqrestore(&i8042_lock, flags);
+       return ret;
+}
+EXPORT_SYMBOL(i8042_install_filter);
+
+int i8042_remove_filter(bool (*filter)(unsigned char data, unsigned char str,
+                                      struct serio *port))
+{
+       unsigned long flags;
+       int ret = 0;
+
+       spin_lock_irqsave(&i8042_lock, flags);
+
+       if (i8042_platform_filter != filter) {
+               ret = -EINVAL;
+               goto out;
+       }
+
+       i8042_platform_filter = NULL;
+
+out:
+       spin_unlock_irqrestore(&i8042_lock, flags);
+       return ret;
+}
+EXPORT_SYMBOL(i8042_remove_filter);
+
 /*
  * The i8042_wait_read() and i8042_wait_write functions wait for the i8042 to
  * be ready for reading values from it / writing values to it.
@@ -373,7 +417,8 @@ static void i8042_stop(struct serio *serio)
  * It is called from i8042_interrupt and thus is running with interrupts
  * off and i8042_lock held.
  */
-static bool i8042_filter(unsigned char data, unsigned char str)
+static bool i8042_filter(unsigned char data, unsigned char str,
+                        struct serio *serio)
 {
        if (unlikely(i8042_suppress_kbd_ack)) {
                if ((~str & I8042_STR_AUXDATA) &&
@@ -384,6 +429,11 @@ static bool i8042_filter(unsigned char data, unsigned char str)
                }
        }
 
+       if (i8042_platform_filter && i8042_platform_filter(data, str, serio)) {
+               dbg("Filtered out by platfrom filter\n");
+               return true;
+       }
+
        return false;
 }
 
@@ -396,6 +446,7 @@ static bool i8042_filter(unsigned char data, unsigned char str)
 static irqreturn_t i8042_interrupt(int irq, void *dev_id)
 {
        struct i8042_port *port;
+       struct serio *serio;
        unsigned long flags;
        unsigned char str, data;
        unsigned int dfl;
@@ -462,18 +513,19 @@ static irqreturn_t i8042_interrupt(int irq, void *dev_id)
        }
 
        port = &i8042_ports[port_no];
+       serio = port->exists ? port->serio : NULL;
 
        dbg("%02x <- i8042 (interrupt, %d, %d%s%s)",
            data, port_no, irq,
            dfl & SERIO_PARITY ? ", bad parity" : "",
            dfl & SERIO_TIMEOUT ? ", timeout" : "");
 
-       filtered = i8042_filter(data, str);
+       filtered = i8042_filter(data, str, serio);
 
        spin_unlock_irqrestore(&i8042_lock, flags);
 
        if (likely(port->exists && !filtered))
-               serio_interrupt(port->serio, data, dfl);
+               serio_interrupt(serio, data, dfl);
 
  out:
        return IRQ_RETVAL(ret);