From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bjorn Andersson Subject: Re: [PATCH 2/2] pinctrl: qcom: ipq4019: add remaining pin definitions Date: Wed, 5 Jul 2017 23:02:43 -0700 Message-ID: <20170706060243.GP18666@tuxbook> References: <1975629.nrP45RYYW5@debian64> <20170520050824.GS12920@tuxbook> <2018547.lycQhaDrJg@debian64> <20170523192857.GW12920@tuxbook> <001b01d2d48e$3f366660$bda33320$@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <001b01d2d48e$3f366660$bda33320$@codeaurora.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Ram Chandra Jangir Cc: 'Christian Lamparter' , linux-gpio-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, 'Linus Walleij' , 'Rob Herring' , 'Mark Rutland' , 'John Crispin' List-Id: linux-gpio@vger.kernel.org On Wed 24 May 06:04 PDT 2017, Ram Chandra Jangir wrote: > > > On Wednesday, May 24, 2017 12:59 AM CEST Bjorn Andersson wrote: [..] > >This makes me wonder what wifi1_uart (and uart1) actually is... > > >The wifi\d_uart seems to have 5 pins in its group and wifi\d_uart\d seems > to be two sets of two pins. So perhaps this is some alternative routing and > wifi0_uart0 and wifi0_uart1 is actually the same function? > > >@Ram, can you help us out here? > Ram, thanks for your answer. Unfortunately I missed this mail until Christian posted the new version of the patch. Unfortunately I don't understand the functions provided here, so I hope you can help me better understand what's going on. > wifi0_uart0 and wifi0_uart1 are different functions, and they are mapped as > below: > wifi0_uart --> wifi0 uart RTS > wifi0_uart0 --> wifi0 uart RxD > wifi0_uart1 --> wifi0 uart CTS Christian has the following groups of pins for each function: wifi0_uart: pin 8, 9, 11, 19 and 62 wifi0_uart0: pin 9 and 10 wifi0_uart1: pin 18 and 63 It's common to see alternative muxing of functions, so I'm guessing that wifi0_uart1 is one of these. Is this correct? But why is there 5 pins for RTS? Why is receive (wifi0_uart0) two adjacent pins? Are they perhaps Rx and Tx? Why do we have a CTS line if we only have RxD, no TxD? > > wifi1_uart --> wifi1 uart TxD > wifi1_uart0 --> wifi1 uart RxD > wifi1_uart1 --> wifi1 uart CTS > Why is there no RTS for this when it seems bidirectional? Regards, Bjorn -- 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