2 files changed, 72 insertions, 4 deletions

diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index 634da68f7f35..d84a36e545f6 100644
--- 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);
diff --git a/include/linux/i8042.h b/include/linux/i8042.h
index 60c3360ef6ad..9bf6870ee5f4 100644
--- a/include/linux/i8042.h
+++ b/include/linux/i8042.h
@@ -39,6 +39,10 @@ void i8042_lock_chip(void);
 void i8042_unlock_chip(void);
 int i8042_command(unsigned char *param, int command);
 bool i8042_check_port_owner(const struct serio *);
+int i8042_install_filter(bool (*filter)(unsigned char data, unsigned char str,
+                                        struct serio *serio));
+int i8042_remove_filter(bool (*filter)(unsigned char data, unsigned char str,
+                                       struct serio *serio));
 
 #else
 
@@ -52,7 +56,7 @@ void i8042_unlock_chip(void)
 
 int i8042_command(unsigned char *param, int command)
 {
-        return -ENOSYS;
+        return -ENODEV;
 }
 
 bool i8042_check_port_owner(const struct serio *serio)
@@ -60,6 +64,18 @@ bool i8042_check_port_owner(const struct serio *serio)
         return false;
 }
 
+int i8042_install_filter(bool (*filter)(unsigned char data, unsigned char str,
+                                        struct serio *serio))
+{
+        return -ENODEV;
+}
+
+int i8042_remove_filter(bool (*filter)(unsigned char data, unsigned char str,
+                                       struct serio *serio))
+{
+        return -ENODEV;
+}
+
 #endif
 
 #endif