From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from na01-by2-obe.outbound.protection.outlook.com (mail-by2on0142.outbound.protection.outlook.com [207.46.100.142]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 3F6CD1A019F for ; Fri, 12 Sep 2014 20:41:18 +1000 (EST) Date: Fri, 12 Sep 2014 18:40:55 +0800 From: Shengjiu Wang To: Markus Pargmann Subject: Re: [PATCH V2] ASoC: fsl_ssi: refine ipg clock usage in this module Message-ID: <20140912104054.GA6420@audiosh1> References: <27584da8e3ab291ab8dbcbb411579613f8384a59.1410413734.git.shengjiu.wang@freescale.com> <20140911225737.GA13926@Alpha> <20140912020110.GA414@audiosh1> <20140912061706.GA10680@pengutronix.de> <20140912071426.GA30261@audiosh1> <20140912085446.GA8844@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" In-Reply-To: <20140912085446.GA8844@pengutronix.de> Cc: alsa-devel@alsa-project.org, lgirdwood@gmail.com, tiwai@suse.de, Li.Xiubo@freescale.com, timur@tabi.org, perex@perex.cz, Nicolin Chen , broonie@kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, Sep 12, 2014 at 10:54:46AM +0200, Markus Pargmann wrote: > On Fri, Sep 12, 2014 at 03:14:28PM +0800, Shengjiu Wang wrote: > > On Fri, Sep 12, 2014 at 08:17:06AM +0200, Markus Pargmann wrote: > > > Hi, > > > > > > On Fri, Sep 12, 2014 at 10:01:12AM +0800, Shengjiu Wang wrote: > > > > On Thu, Sep 11, 2014 at 03:57:37PM -0700, Nicolin Chen wrote: > > > > > On Thu, Sep 11, 2014 at 01:38:29PM +0800, Shengjiu Wang wrote: > > > > > > Move the ipg clock enable and disable operation to startup and shutdown, > > > > > > that is only enable ipg clock when ssi is working. Keep clock is disabled > > > > > > when ssi is in idle. > > > > > > otherwise, _fsl_ssi_set_dai_fmt function need to be called in probe, > > > > > > so add ipg clock control for it. > > > > > > > > > > It seems to be no objection so far against my last suggestion to > > > > > use regmap's mmio_clk() for named ipg clk only. So you may still > > > > > consider about that. > > > > > > > > > I think mmio_clk() can be put to another patch. and this patch only for clk_enable() > > > > and clk_disable() operation. > > > > > > I would also prefer Nicolin's suggestion using regmap's mmio clk. I > > > think it may be better to not add this particular patch at all and just > > > go with the mmio_clk patch. It should be easy enough to just add the > > > clock names to the devicetrees. That way we can avoid all those clock > > > enable/disable function calls. > > > > > I considered if use Nicolin's suggestion, I still need ot add those > > enable/disable function calls, because I want to remove the enable/disable > > function call in fsl_ssi_imx_probe, then I need to add enable/disable > > function call in _fsl_ssi_set_dai_fmt(), which is called in fsl_ssi_probe(). > > _fsl_ssi_set_dai_fmt() need to access the registers. > > I think Nicolin's suggestion was to check for a clock named "ipg". If it > exists, you can simply use devm_regmap_init_mmio_clk(). Otherwise you > could fallback to the old behaviour and get the first clock and enable > it without disabling it after the probe function. > > After that, you could add the clock-names property to the devicetrees > and have the same result. > Ok, I have sent V3 for review. please check. wang shengjiu > > > > > > > > > > > Anyway, I'd like to do thing in parallel. So I just simply tested > > > > > it on my side and its works fine, it may still need to be tested > > > > > by others though. > > > > > > > > > > Nicolina > > > > > > > > Hi Markus > > > > > > > > could you please review it, and share your comments? > > > > > > I think the clock enabling for AC97 is missing in your patch. > > > > > I add clock enable in fsl_ssi_startup(), I think it is enough for AC97, does it? > > No. We export ac97 read/write ops for the whole AC97 stuff. These may be > used outside of the usual startup/shutdown which is done for substreams. > It may work to have the ipg clock enabled in > fsl_ssi_ac97_read/fsl_ssi_ac97_write. > > Best regards, > > Markus > > -- > Pengutronix e.K. | | > Industrial Linux Solutions | http://www.pengutronix.de/ | > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |