From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Date: Fri, 20 Nov 2015 08:22:16 +0000 Subject: Re: [PATCH 00/25] serial: sh-sci: Add external clock and BRG Support Message-Id: List-Id: References: <1447958344-836-1-git-send-email-geert+renesas@glider.be> <1662323.uZlFXR9U2a@avalon> In-Reply-To: <1662323.uZlFXR9U2a@avalon> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Laurent Pinchart Cc: Geert Uytterhoeven , Greg Kroah-Hartman , Simon Horman , Magnus Damm , Yoshinori Sato , "linux-serial@vger.kernel.org" , Linux-sh list , "linux-kernel@vger.kernel.org" Hi Laurent, On Thu, Nov 19, 2015 at 10:08 PM, Laurent Pinchart wrote: > For patches 3-6, 13, 15-16 and 22 and 24, > > Reviewed-by: Laurent Pinchart Many thanks for your review comments! > I'm not sure I'd bother with patch 25/25, but I'm not against merging it > either. I'd be surprised if the serial driver still worked at all on SH :-) It should not cause problems, as long as sh7734 doesn't add the optional clocks ;-) > On Thursday 19 November 2015 19:38:39 Geert Uytterhoeven wrote: >> This patch series adds support to the Renesas SCI serial driver for >> - the optional external clock on (H)SCI(F) and some SCIFA, where this >> pin can serve as a clock input, >> - the optional clock sources for the Baud Rate Generator for External >> Clock (BRG), as found on some SCIF variants and on HSCIF. > > Could you briefly explain (and even better in a source code comment) how you > handle baud rate calculation with the chained BRGs ? I'll do that. Note that there's no chaining of BRGs, only muxing (so yes, it needs more clarification ;-). There can be 4 possible sources for the sampling clock: 1. Internal BRG (BRR register), 2. (H)SCK, 3. BRG for external clock a. Using SCIF_CLK, b. Using the bus clock. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds