From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Anholt Subject: Re: [PATCH V3 3/4] serial: bcm2835: add driver for bcm2835-aux-uart Date: Thu, 28 Jan 2016 14:34:14 -0800 Message-ID: <87h9hxfi55.fsf@eliezer.anholt.net> References: <1453032932-2512-1-git-send-email-kernel@martin.sperl.org> <1453032932-2512-4-git-send-email-kernel@martin.sperl.org> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha512; protocol="application/pgp-signature" Return-path: In-Reply-To: <1453032932-2512-4-git-send-email-kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Rob Herring , Stephen Warren , Lee Jones , Russell King , Greg Kroah-Hartman , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-rpi-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-serial-u79uwXL29TY76Z2rM5mHXA@public.gmane.org Cc: Martin Sperl List-Id: devicetree@vger.kernel.org --=-=-= Content-Type: text/plain kernel-TqfNSX0MhmxHKSADF0wUEw@public.gmane.org writes: > From: Martin Sperl > > The bcm2835 SOC contains an auxiliary uart, which is very close > to the ns16550 with some differences. > > The big difference is that the uart HW is not using an internal divider > of 16 but 8, which results in an effictive baud-rate being twice > the requested baud-rate. > > This driver handles this device correctly and handles the difference in > the HW divider by scaling up the clock by a factor of 2. > > The approach to write a separate (wrapper) driver instead of using a > multiplying clock and "ns16550" as compatibility in the device-tree > has been recommended by Stephen Warren. > > Signed-off-by: Martin Sperl Acked-by: Eric Anholt --=-=-= Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBCgAGBQJWqpdnAAoJELXWKTbR/J7oQ0QQAII0o1h+Xu2zmmxHiLYLcyOu R7o++ZUO7h94Hx0b0wgXblL6STooRt5Oiap2/Hd3ekjdcUrF/gfxgz/hWHJX8KC9 gMmHv+El9VpWZEbknFurp5re8mFd9lNCzdw8725JbzEJXVaZTnEoHOm0bpFLX44z 4aRlYHlfwqBBAMZJMOKLoKmuoXEWuJDXtY1/f0/fe/+LoLUTwLU8Z19PjYE6nthJ I0QlHQN8PHZM8o7OAkJqthw72jpqH8D24g0UWz7gupxGyu3IgpqQSN7vfRasGiua ri3yEtS6G13PIOGwQKJi1UPPXPOs2xNZiIEiUKAQaCj7b9JPYGUzUjaUnWVFa2Kt 0xy/DfrNwbOK+XDzGUlG04uf4AfgKPJZjdQKqCGVFKFtg/Dcr2YkcKk4WDKK+mCR JC+Zfnrv/E6sDPKj8cAPxruj6pwgfY/8UxVlKA4vSLX8VIYQAKa98C3QMghMjZe3 g62E8KrDQZtwdlculDO53fJyfU1K/my84xs+ZmgIaTt4Kb0Ow7MZ1tZjjgA3237q JntPhxWzN975Ulkr8TTmZCX0cyiBadc90piA3Sighj4NbDGPB1E7m6Cpl0mL29Vn Ip/iwrJhIBBtREcMRPOohLL4kjg3ElIunamFn7UlQCr8pX+sZVDDbpvL+ODSAy+m ACAH2xv665cvKOOEFjVV =AVDY -----END PGP SIGNATURE----- --=-=-=-- -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html