From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hongwei Zhang Subject: [v6 2/2] gpio: aspeed: Add SGPIO driver Date: Mon, 29 Jul 2019 16:43:46 -0400 Message-ID: <1564433026-32163-1-git-send-email-hongweiz@ami.com> References: <1563564291-9692-3-git-send-email-hongweiz@ami.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1563564291-9692-3-git-send-email-hongweiz@ami.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Linus Walleij , Andrew Jeffery Cc: devicetree@vger.kernel.org, linux-aspeed@lists.ozlabs.org, linux-kernel@vger.kernel.org, Bartosz Golaszewski , Joel Stanley , Hongwei Zhang , linux-arm-kernel@lists.infradead.org List-Id: devicetree@vger.kernel.org Hello Linus, Thanks for your detailed comments. We just submitted a v6 of sgpio-aspeed.c, it includes the updates based on your initial feedback: 1. fix a bug in aspeed_sgpio_dir_out() 2. some comments clean up. Regards, --Hongwei > From: Linus Walleij > Sent: Sunday, July 28, 2019 7:38 PM > To: Hongwei Zhang > Cc: Andrew Jeffery; linux-gpio; Joel Stanley; linux-aspeed; Bartosz Golaszewski; linux-kernel; linux- > arm-kernel > Subject: Re: [v5 2/2] gpio: aspeed: Add SGPIO driver > > On Mon, Jul 22, 2019 at 10:37 PM Hongwei Zhang wrote: > > > As you suspected it correctly, AST2500 utilizes all the 32 bits of the > > registers (data value, interrupt, etc...), such that using 8-bit bands > > [7:0]/[15:8]/23:16]/[31:24] of GPIO_200H for SGPIO_A/B/C/D . > > so registering 10 gpiochip drivers separately will make code more > > complicated, for example gpio_200 register (data_value reg) has to be > > shared by 4 gpiochip instances, and the same is true for gpio204 > > (interrupt reg), and other more registers. > > So we would prefer to keeping current implementation. > > OK this is a pretty good argument. My review assumed one 32-bit register was not shared between > banks but it is, I see. > > The above situation can be managed by regmap, but that will just a different complexity so go with this > approach then. > > Yours, > Linus Walleij