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path: root/drivers/input/serio/i8042.c
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Diffstat (limited to 'drivers/input/serio/i8042.c')
-rw-r--r--drivers/input/serio/i8042.c88
1 files changed, 79 insertions, 9 deletions
diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index 1df02d25aca..d84a36e545f 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.
@@ -369,6 +413,31 @@ static void i8042_stop(struct serio *serio)
}
/*
+ * i8042_filter() filters out unwanted bytes from the input data stream.
+ * 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,
+ struct serio *serio)
+{
+ if (unlikely(i8042_suppress_kbd_ack)) {
+ if ((~str & I8042_STR_AUXDATA) &&
+ (data == 0xfa || data == 0xfe)) {
+ i8042_suppress_kbd_ack--;
+ dbg("Extra keyboard ACK - filtered out\n");
+ return true;
+ }
+ }
+
+ if (i8042_platform_filter && i8042_platform_filter(data, str, serio)) {
+ dbg("Filtered out by platfrom filter\n");
+ return true;
+ }
+
+ return false;
+}
+
+/*
* i8042_interrupt() is the most important function in this driver -
* it handles the interrupts from the i8042, and sends incoming bytes
* to the upper layers.
@@ -377,13 +446,16 @@ static void i8042_stop(struct serio *serio)
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;
unsigned int port_no;
+ bool filtered;
int ret = 1;
spin_lock_irqsave(&i8042_lock, flags);
+
str = i8042_read_status();
if (unlikely(~str & I8042_STR_OBF)) {
spin_unlock_irqrestore(&i8042_lock, flags);
@@ -391,8 +463,8 @@ static irqreturn_t i8042_interrupt(int irq, void *dev_id)
ret = 0;
goto out;
}
+
data = i8042_read_data();
- spin_unlock_irqrestore(&i8042_lock, flags);
if (i8042_mux_present && (str & I8042_STR_AUXDATA)) {
static unsigned long last_transmit;
@@ -441,21 +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" : "");
- if (unlikely(i8042_suppress_kbd_ack))
- if (port_no == I8042_KBD_PORT_NO &&
- (data == 0xfa || data == 0xfe)) {
- i8042_suppress_kbd_ack--;
- goto out;
- }
+ filtered = i8042_filter(data, str, serio);
+
+ spin_unlock_irqrestore(&i8042_lock, flags);
- if (likely(port->exists))
- serio_interrupt(port->serio, data, dfl);
+ if (likely(port->exists && !filtered))
+ serio_interrupt(serio, data, dfl);
out:
return IRQ_RETVAL(ret);