Does ichigo's dad know ichigo is a substitute soul reaper?

Kurosaki Isshin is a man with mysterious past and so it might be a spoiler if you are not updated with this series so here we go

"Isshin is a former captain of Gotei 13 who left the squad for a women of course, he was helped by Urahara when he left the squad so yeah he knows everything about Ichigo, Rukia and substitute shinigami thing. He did not helped Ichigo during Soul Society arc was because

a. he wanted to protect his two girls and

b. he was not fully recovered from the incident that lead him to become a fugitive for soul society."