Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754181Ab0FCT2b (ORCPT ); Thu, 3 Jun 2010 15:28:31 -0400 Received: from mailhost.informatik.uni-hamburg.de ([134.100.9.70]:56426 "EHLO mailhost.informatik.uni-hamburg.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753331Ab0FCT2a (ORCPT ); Thu, 3 Jun 2010 15:28:30 -0400 Message-ID: <4C080230.1070909@metafoo.de> Date: Thu, 03 Jun 2010 21:27:44 +0200 From: Lars-Peter Clausen User-Agent: Mozilla-Thunderbird 2.0.0.24 (X11/20100329) MIME-Version: 1.0 To: Mark Brown CC: Ralf Baechle , linux-mips@linux-mips.org, linux-kernel@vger.kernel.org, Liam Girdwood , alsa-devel@alsa-project.org Subject: Re: [RFC][PATCH 21/26] alsa: ASoC: Add JZ4740 ASoC support References: <1275505397-16758-1-git-send-email-lars@metafoo.de> <1275505950-17334-5-git-send-email-lars@metafoo.de> <20100603175511.GI2762@rakim.wolfsonmicro.main> In-Reply-To: <20100603175511.GI2762@rakim.wolfsonmicro.main> X-Enigmail-Version: 0.95.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2021 Lines: 73 Mark Brown wrote: > On Wed, Jun 02, 2010 at 09:12:27PM +0200, Lars-Peter Clausen wrote: > > Again, overall very good. > > >> +static int jz4740_i2s_set_clkdiv(struct snd_soc_dai *dai, int div_id, int div) >> +{ >> + struct jz4740_i2s *i2s = jz4740_dai_to_i2s(dai); >> + >> + switch (div_id) { >> + case JZ4740_I2S_BIT_CLK: >> + if (div & 1 || div > 16) >> + return -EINVAL; >> + jz4740_i2s_write(i2s, JZ_REG_AIC_CLK_DIV, div - 1); >> + break; >> + default: >> + return -EINVAL; >> + } >> + >> + return 0; >> +} >> > > You can probably figure out the bit clock automatically by default... > Hm, yes, you are right. > >> + if (dai->active) { >> + conf = jz4740_i2s_read(i2s, JZ_REG_AIC_CONF); >> + conf &= ~JZ_AIC_CONF_ENABLE; >> + jz4740_i2s_write(i2s, JZ_REG_AIC_CONF, conf); >> + >> + clk_disable(i2s->clk_i2s); >> + } >> + >> + clk_disable(i2s->clk_aic); >> > > Might make sense to manage this clock dynamically at runtime too for a > little extra power saving? > I think I tried it once and the power savings were marginal. On the other hand each callback would have to make sure the clock is enabled before accessing registers and disabling it again if it was disabled. > >> + i2s->clk_aic = clk_get(&pdev->dev, "aic"); >> + if (IS_ERR(i2s->clk_aic)) { >> + ret = PTR_ERR(i2s->clk_aic); >> + goto err_iounmap; >> + } >> + >> + i2s->clk_i2s = clk_get(&pdev->dev, "i2s"); >> + if (IS_ERR(i2s->clk_i2s)) { >> + ret = PTR_ERR(i2s->clk_i2s); >> + goto err_iounmap; >> + } >> > > Ideally you'd free the AIC clock when unwinding (and later stop it after > it was enabled). Though since you don't do any error checking after > this point it's kind of academic :) > > It should at least freed if the i2s clock is not found. - Lars -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/