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, 5 insertions, 2 deletions

diff --git a/drivers/media/video/ivtv/ivtv-i2c.c b/drivers/media/video/ivtv/ivtv-i2c.c
index b9c71e61f7d6..d4cc3365038e 100644
--- a/drivers/media/video/ivtv/ivtv-i2c.c
+++ b/drivers/media/video/ivtv/ivtv-i2c.c
@@ -564,13 +564,15 @@ static struct i2c_adapter ivtv_i2c_adap_template = {
         .owner = THIS_MODULE,
 };
 
+#define IVTV_ALGO_BIT_TIMEOUT   (2)     /* seconds */
+
 static const struct i2c_algo_bit_data ivtv_i2c_algo_template = {
         .setsda         = ivtv_setsda_old,
         .setscl         = ivtv_setscl_old,
         .getsda         = ivtv_getsda_old,
         .getscl         = ivtv_getscl_old,
-        .udelay         = 10,
-        .timeout        = 200,
+        .udelay         = IVTV_DEFAULT_I2C_CLOCK_PERIOD / 2,  /* microseconds */
+        .timeout        = IVTV_ALGO_BIT_TIMEOUT * HZ,         /* jiffies */
 };
 
 static struct i2c_client ivtv_i2c_client_template = {
@@ -602,6 +604,7 @@ int init_ivtv_i2c(struct ivtv *itv)
                 memcpy(&itv->i2c_algo, &ivtv_i2c_algo_template,
                        sizeof(struct i2c_algo_bit_data));
         }
+        itv->i2c_algo.udelay = itv->options.i2c_clock_period / 2;
         itv->i2c_algo.data = itv;
         itv->i2c_adap.algo_data = &itv->i2c_algo;