V4L/DVB (13442): ivtv: Add module parameter to adjust I2C SCL clock period per board

Add a module parameter to adjust I2C SCL clock period per board.  This allows
some experimental fine tuning by end users to overcome quirky I2C device
problems.

Reported-by: "Aleksandr V. Piskunov" <aleksandr.v.piskunov@gmail.com>
Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 4 insertions, 0 deletions

diff --git a/drivers/media/video/ivtv/ivtv-driver.h b/drivers/media/video/ivtv/ivtv-driver.h
index 440f7328a7ed..2b3db90afb74 100644
--- a/drivers/media/video/ivtv/ivtv-driver.h
+++ b/drivers/media/video/ivtv/ivtv-driver.h
@@ -176,12 +176,16 @@ extern int ivtv_debug;
 
 #define IVTV_MAX_PGM_INDEX (400)
 
+/* Default I2C SCL period in microseconds */
+#define IVTV_DEFAULT_I2C_CLOCK_PERIOD   20
+
 struct ivtv_options {
         int kilobytes[IVTV_MAX_STREAMS];        /* size in kilobytes of each stream */
         int cardtype;                           /* force card type on load */
         int tuner;                              /* set tuner on load */
         int radio;                              /* enable/disable radio */
         int newi2c;                             /* new I2C algorithm */
+        int i2c_clock_period;                   /* period of SCL for I2C bus */
 };
 
 /* ivtv-specific mailbox template */