1 files changed, 41 insertions, 0 deletions

diff --git a/drivers/media/video/cx18/cx18-gpio.c b/drivers/media/video/cx18/cx18-gpio.c
index d753a40973ba..3d495dba4983 100644
--- a/drivers/media/video/cx18/cx18-gpio.c
+++ b/drivers/media/video/cx18/cx18-gpio.c
@@ -83,6 +83,47 @@ void cx18_reset_i2c_slaves_gpio(struct cx18 *cx)
         mutex_unlock(&cx->gpio_lock);
 }
 
+void cx18_reset_ir_gpio(void *data)
+{
+        struct cx18 *cx = ((struct cx18_i2c_algo_callback_data *)data)->cx;
+        const struct cx18_gpio_i2c_slave_reset *p;
+
+        p = &cx->card->gpio_i2c_slave_reset;
+
+        if (p->ir_reset_mask == 0)
+                return;
+
+        CX18_DEBUG_INFO("Resetting IR microcontroller\n");
+
+        /*
+           Assert timing for the Z8F0811 on HVR-1600 boards:
+           1. Assert RESET for min of 4 clock cycles at 18.432 MHz to initiate
+           2. Reset then takes 66 WDT cycles at 10 kHz + 16 xtal clock cycles
+                (6,601,085 nanoseconds ~= 7 milliseconds)
+           3. DBG pin must be high before chip exits reset for normal operation.
+                DBG is open drain and hopefully pulled high since we don't
+                normally drive it (GPIO 1?) for the HVR-1600
+           4. Z8F0811 won't exit reset until RESET is deasserted
+        */
+        mutex_lock(&cx->gpio_lock);
+        cx->gpio_val = cx->gpio_val & ~p->ir_reset_mask;
+        gpio_write(cx);
+        mutex_unlock(&cx->gpio_lock);
+        schedule_timeout_uninterruptible(msecs_to_jiffies(p->msecs_asserted));
+
+        /*
+           Zilog comes out of reset, loads reset vector address and executes
+           from there. Required recovery delay unknown.
+        */
+        mutex_lock(&cx->gpio_lock);
+        cx->gpio_val = cx->gpio_val | p->ir_reset_mask;
+        gpio_write(cx);
+        mutex_unlock(&cx->gpio_lock);
+        schedule_timeout_uninterruptible(msecs_to_jiffies(p->msecs_recovery));
+}
+EXPORT_SYMBOL(cx18_reset_ir_gpio);
+/* This symbol is exported for use by an infrared module for the IR-blaster */
+
 void cx18_gpio_init(struct cx18 *cx)
 {
         mutex_lock(&cx->gpio_lock);