diff options
Diffstat (limited to 'drivers/input/serio/i8042.c')
| -rw-r--r-- | drivers/input/serio/i8042.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c index eb3ff94af58c..bc56e52b945f 100644 --- a/drivers/input/serio/i8042.c +++ b/drivers/input/serio/i8042.c @@ -87,8 +87,22 @@ static bool i8042_bypass_aux_irq_test; #include "i8042.h" +/* + * i8042_lock protects serialization between i8042_command and + * the interrupt handler. + */ static DEFINE_SPINLOCK(i8042_lock); +/* + * Writers to AUX and KBD ports as well as users issuing i8042_command + * directly should acquire i8042_mutex (by means of calling + * i8042_lock_chip() and i8042_unlock_ship() helpers) to ensure that + * they do not disturb each other (unfortunately in many i8042 + * implementations write to one of the ports will immediately abort + * command that is being processed by another port). + */ +static DEFINE_MUTEX(i8042_mutex); + struct i8042_port { struct serio *serio; int irq; @@ -113,6 +127,18 @@ static struct platform_device *i8042_platform_device; static irqreturn_t i8042_interrupt(int irq, void *dev_id); +void i8042_lock_chip(void) +{ + mutex_lock(&i8042_mutex); +} +EXPORT_SYMBOL(i8042_lock_chip); + +void i8042_unlock_chip(void) +{ + mutex_unlock(&i8042_mutex); +} +EXPORT_SYMBOL(i8042_unlock_chip); + /* * 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. @@ -1161,6 +1187,21 @@ static void __devexit i8042_unregister_ports(void) } } +/* + * Checks whether port belongs to i8042 controller. + */ +bool i8042_check_port_owner(const struct serio *port) +{ + int i; + + for (i = 0; i < I8042_NUM_PORTS; i++) + if (i8042_ports[i].serio == port) + return true; + + return false; +} +EXPORT_SYMBOL(i8042_check_port_owner); + static void i8042_free_irqs(void) { if (i8042_aux_irq_registered) |