From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Tue, 2 Jun 2015 19:15:36 +0200 From: Alexandre Belloni To: Boris Brezillon Cc: Cyrille Pitchen , nicolas.ferre@atmel.com, linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: Re: [PATCH v2 2/2] clk: at91: add Flexcom clock Message-ID: <20150602171536.GG1715@piout.net> References: <62cb26952d0688c6f37ad84d253d5302818a20ae.1433264017.git.cyrille.pitchen@atmel.com> <20150602190435.4698a4db@bbrezillon> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20150602190435.4698a4db@bbrezillon> Sender: linux-kernel-owner@vger.kernel.org List-ID: On 02/06/2015 at 19:04:35 +0200, Boris Brezillon wrote : > Hi Cyrille, > > On Tue, 2 Jun 2015 18:57:19 +0200 > Cyrille Pitchen wrote: > > > This driver supports the new Atmel Flexcom. The Flexcom is a wrapper which > > integrates one SPI controller, one I2C controller and one USART. Only one > > function can be enabled at a time. This driver selects the function once for > > all, when the Flexcom is probed, according to the value of the new > > "atmel,flexcom-mode" device tree property. > > > > This driver has chosen to present the Flexcom to the system as a clock so the > > implementation is seamless for the existing Atmel SPI, I2C and USART drivers. > > Could detail a bit more why you chose to represent this flexcom IP as > a clock device ? > > I don't like to use this 'DT should represent real hardware' argument, > but to me, it looks like you're trying to use a false hardware > representation to avoid changing the peripheral drivers code, which is > wrong since the DT is supposed to represent the hardware blocks. > > How about representing the flexcom as an MFD instead ? > It should probably be represented as an MFD. The MFD driver will parse the chosen configuration and the probe the correct driver. You can have a look at the recent ST LPC driver from Lee. -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com From mboxrd@z Thu Jan 1 00:00:00 1970 From: alexandre.belloni@free-electrons.com (Alexandre Belloni) Date: Tue, 2 Jun 2015 19:15:36 +0200 Subject: [PATCH v2 2/2] clk: at91: add Flexcom clock In-Reply-To: <20150602190435.4698a4db@bbrezillon> References: <62cb26952d0688c6f37ad84d253d5302818a20ae.1433264017.git.cyrille.pitchen@atmel.com> <20150602190435.4698a4db@bbrezillon> Message-ID: <20150602171536.GG1715@piout.net> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 02/06/2015 at 19:04:35 +0200, Boris Brezillon wrote : > Hi Cyrille, > > On Tue, 2 Jun 2015 18:57:19 +0200 > Cyrille Pitchen wrote: > > > This driver supports the new Atmel Flexcom. The Flexcom is a wrapper which > > integrates one SPI controller, one I2C controller and one USART. Only one > > function can be enabled at a time. This driver selects the function once for > > all, when the Flexcom is probed, according to the value of the new > > "atmel,flexcom-mode" device tree property. > > > > This driver has chosen to present the Flexcom to the system as a clock so the > > implementation is seamless for the existing Atmel SPI, I2C and USART drivers. > > Could detail a bit more why you chose to represent this flexcom IP as > a clock device ? > > I don't like to use this 'DT should represent real hardware' argument, > but to me, it looks like you're trying to use a false hardware > representation to avoid changing the peripheral drivers code, which is > wrong since the DT is supposed to represent the hardware blocks. > > How about representing the flexcom as an MFD instead ? > It should probably be represented as an MFD. The MFD driver will parse the chosen configuration and the probe the correct driver. You can have a look at the recent ST LPC driver from Lee. -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre Belloni Subject: Re: [PATCH v2 2/2] clk: at91: add Flexcom clock Date: Tue, 2 Jun 2015 19:15:36 +0200 Message-ID: <20150602171536.GG1715@piout.net> References: <62cb26952d0688c6f37ad84d253d5302818a20ae.1433264017.git.cyrille.pitchen@atmel.com> <20150602190435.4698a4db@bbrezillon> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20150602190435.4698a4db@bbrezillon> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Boris Brezillon Cc: Cyrille Pitchen , nicolas.ferre-AIFe0yeh4nAAvxtiuMwx3w@public.gmane.org, linux-clk-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On 02/06/2015 at 19:04:35 +0200, Boris Brezillon wrote : > Hi Cyrille, > > On Tue, 2 Jun 2015 18:57:19 +0200 > Cyrille Pitchen wrote: > > > This driver supports the new Atmel Flexcom. The Flexcom is a wrapper which > > integrates one SPI controller, one I2C controller and one USART. Only one > > function can be enabled at a time. This driver selects the function once for > > all, when the Flexcom is probed, according to the value of the new > > "atmel,flexcom-mode" device tree property. > > > > This driver has chosen to present the Flexcom to the system as a clock so the > > implementation is seamless for the existing Atmel SPI, I2C and USART drivers. > > Could detail a bit more why you chose to represent this flexcom IP as > a clock device ? > > I don't like to use this 'DT should represent real hardware' argument, > but to me, it looks like you're trying to use a false hardware > representation to avoid changing the peripheral drivers code, which is > wrong since the DT is supposed to represent the hardware blocks. > > How about representing the flexcom as an MFD instead ? > It should probably be represented as an MFD. The MFD driver will parse the chosen configuration and the probe the correct driver. You can have a look at the recent ST LPC driver from Lee. -- Alexandre Belloni, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com -- 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