Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757421Ab3EVVWx (ORCPT ); Wed, 22 May 2013 17:22:53 -0400 Received: from mail-oa0-f44.google.com ([209.85.219.44]:34648 "EHLO mail-oa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757148Ab3EVVWw (ORCPT ); Wed, 22 May 2013 17:22:52 -0400 From: Felipe Ferreri Tonello To: Guennadi Liakhovetski Cc: linux-mmc@vger.kernel.org, ben-linux@fluff.org, cjb@laptop.org, arnd@arndb.de, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] mmc: sdhci: Added set_power sdhci_ops handler. Date: Wed, 22 May 2013 14:22:45 -0700 Message-ID: <2537252.KzShHU8h54@localhost.localdomain> User-Agent: KMail/4.10.2 (Linux/3.9.2-200.fc18.x86_64; KDE/4.10.2; x86_64; ; ) In-Reply-To: References: <1369244832-23868-1-git-send-email-eu@felipetonello.com> <1369244832-23868-2-git-send-email-eu@felipetonello.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2738 Lines: 96 Hi Guennadi, On Wednesday, May 22, 2013 10:30:40 PM Guennadi Liakhovetski wrote: > On Wed, 22 May 2013, Felipe F. Tonello wrote: > > From: "Felipe F. Tonello" > > > > This is useful for power managment purposes if a sdhci child host wants to > > turn off some other peripheral also. > > Sorry, could you elaborate a bit? In what situations is it exactly useful? > And why cannot the regulator API be used there? Sorry about that. One example that I can think of is when you have a wifi module connected as a mmc card via sdio. So you can register a callback function in your machine source code to turn on/off the wifi module based on the mmc host power. I've seen this implementation in others mmc hosts, such as omap. Regards, Felipe > > Thanks > Guennadi > > > Signed-off-by: Felipe F. Tonello > > --- > > > > drivers/mmc/host/sdhci.c | 8 ++++++++ > > drivers/mmc/host/sdhci.h | 1 + > > 2 files changed, 9 insertions(+) > > > > diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c > > index 2ea429c..0a026c6 100644 > > --- a/drivers/mmc/host/sdhci.c > > +++ b/drivers/mmc/host/sdhci.c > > @@ -1244,6 +1244,10 @@ static int sdhci_set_power(struct sdhci_host *host, > > unsigned short power)> > > u8 pwr = 0; > > > > if (power != (unsigned short)-1) { > > > > + > > + if (host->ops->set_power) > > + host->ops->set_power(host, true); > > + > > > > switch (1 << power) { > > > > case MMC_VDD_165_195: > > pwr = SDHCI_POWER_180; > > > > @@ -1259,6 +1263,10 @@ static int sdhci_set_power(struct sdhci_host *host, > > unsigned short power)> > > default: > > BUG(); > > > > } > > > > + } else { > > + > > + if (host->ops->set_power) > > + host->ops->set_power(host, false); > > > > } > > > > if (host->pwr == pwr) > > > > diff --git a/drivers/mmc/host/sdhci.h b/drivers/mmc/host/sdhci.h > > index 379e09d..293d56d 100644 > > --- a/drivers/mmc/host/sdhci.h > > +++ b/drivers/mmc/host/sdhci.h > > @@ -294,6 +294,7 @@ struct sdhci_ops { > > > > void (*platform_resume)(struct sdhci_host *host); > > void (*adma_workaround)(struct sdhci_host *host, u32 intmask); > > void (*platform_init)(struct sdhci_host *host); > > > > + void (*set_power)(struct sdhci_host *host, bool power); > > > > }; > > > > #ifdef CONFIG_MMC_SDHCI_IO_ACCESSORS > > --- > Guennadi Liakhovetski, Ph.D. > Freelance Open-Source Software Developer > http://www.open-technology.de/ -- 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/