From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753502AbbIBIUF (ORCPT ); Wed, 2 Sep 2015 04:20:05 -0400 Received: from mail-pa0-f51.google.com ([209.85.220.51]:32873 "EHLO mail-pa0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753300AbbIBIT7 (ORCPT ); Wed, 2 Sep 2015 04:19:59 -0400 Subject: Re: [RFC 2/3] mmc: sdhci: add host_ops->voltage_switch callback for all other voltages To: Jisheng Zhang References: <1441135938-8056-1-git-send-email-vaibhav.hiremath@linaro.org> <1441135938-8056-3-git-send-email-vaibhav.hiremath@linaro.org> <20150902150442.118d3305@xhacker> Cc: linux-mmc@vger.kernel.org, ulf.hansson@linaro.org, linus.walleij@linaro.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org From: Vaibhav Hiremath Message-ID: <55E6B129.1030002@linaro.org> Date: Wed, 2 Sep 2015 13:49:53 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: <20150902150442.118d3305@xhacker> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wednesday 02 September 2015 12:34 PM, Jisheng Zhang wrote: > On Wed, 2 Sep 2015 01:02:17 +0530 > Vaibhav Hiremath wrote: > >> Currently, the sdhci_do_start_signal_voltage_switch() function invokes >> controller specific voltage switch configuration only for 1.8v usecase; >> but it is required for others as well. >> >> For example, in case of PXA1928 SDH controller, we need to set different >> configuration for 3.3, 1.8 and 1.2 volt support (I/O domain power >> control register). >> >> Signed-off-by: Vaibhav Hiremath >> --- >> Note: >> Currently ->voltage_switch() callback is only supported >> in f_sdh30 driver. And I am not sure on the dependency of execution >> sequence for that device. I could have moved ->voltage_switch() call >> at one common place (above/below), but was not quite sure about it. >> So, replicated/duplicated the call for other voltages. >> >> drivers/mmc/host/sdhci.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c >> index 3dd295f..b59b76d 100644 >> --- a/drivers/mmc/host/sdhci.c >> +++ b/drivers/mmc/host/sdhci.c >> @@ -1753,6 +1753,10 @@ static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host, >> /* Wait for 5ms */ >> usleep_range(5000, 5500); >> >> + /* Some controller need to do more when switching */ >> + if (host->ops->voltage_switch) >> + host->ops->voltage_switch(host, MMC_SIGNAL_VOLTAGE_330); > > Could this be implemented by regulator API? From patch set 3/3, the pxa1928 > voltage_switch hook is to operate the IO pad registers, this seems not belong > to the SDHC IP core. > Not quite sure whether regulator would be right fit for this. Initially I was thinking of making use of pinconf framework, using PIN_CONFIG_POWER_SOURCE, but that too I am not sure is the right way of doing it. Probably, question for pinctrl maintainer. Looping Linus Walleji. Also note that, this configuration is not applicable to all pins/pads, only handpicked pads have this configuration (voltage selection on pads). And this configuration is not part of the same register map. It is part of separate register map (AIB_EXT_REG_BASE), called IO domain power control register. And that Thanks, Vaibhav From mboxrd@z Thu Jan 1 00:00:00 1970 From: vaibhav.hiremath@linaro.org (Vaibhav Hiremath) Date: Wed, 2 Sep 2015 13:49:53 +0530 Subject: [RFC 2/3] mmc: sdhci: add host_ops->voltage_switch callback for all other voltages In-Reply-To: <20150902150442.118d3305@xhacker> References: <1441135938-8056-1-git-send-email-vaibhav.hiremath@linaro.org> <1441135938-8056-3-git-send-email-vaibhav.hiremath@linaro.org> <20150902150442.118d3305@xhacker> Message-ID: <55E6B129.1030002@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Wednesday 02 September 2015 12:34 PM, Jisheng Zhang wrote: > On Wed, 2 Sep 2015 01:02:17 +0530 > Vaibhav Hiremath wrote: > >> Currently, the sdhci_do_start_signal_voltage_switch() function invokes >> controller specific voltage switch configuration only for 1.8v usecase; >> but it is required for others as well. >> >> For example, in case of PXA1928 SDH controller, we need to set different >> configuration for 3.3, 1.8 and 1.2 volt support (I/O domain power >> control register). >> >> Signed-off-by: Vaibhav Hiremath >> --- >> Note: >> Currently ->voltage_switch() callback is only supported >> in f_sdh30 driver. And I am not sure on the dependency of execution >> sequence for that device. I could have moved ->voltage_switch() call >> at one common place (above/below), but was not quite sure about it. >> So, replicated/duplicated the call for other voltages. >> >> drivers/mmc/host/sdhci.c | 8 ++++++++ >> 1 file changed, 8 insertions(+) >> >> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c >> index 3dd295f..b59b76d 100644 >> --- a/drivers/mmc/host/sdhci.c >> +++ b/drivers/mmc/host/sdhci.c >> @@ -1753,6 +1753,10 @@ static int sdhci_do_start_signal_voltage_switch(struct sdhci_host *host, >> /* Wait for 5ms */ >> usleep_range(5000, 5500); >> >> + /* Some controller need to do more when switching */ >> + if (host->ops->voltage_switch) >> + host->ops->voltage_switch(host, MMC_SIGNAL_VOLTAGE_330); > > Could this be implemented by regulator API? From patch set 3/3, the pxa1928 > voltage_switch hook is to operate the IO pad registers, this seems not belong > to the SDHC IP core. > Not quite sure whether regulator would be right fit for this. Initially I was thinking of making use of pinconf framework, using PIN_CONFIG_POWER_SOURCE, but that too I am not sure is the right way of doing it. Probably, question for pinctrl maintainer. Looping Linus Walleji. Also note that, this configuration is not applicable to all pins/pads, only handpicked pads have this configuration (voltage selection on pads). And this configuration is not part of the same register map. It is part of separate register map (AIB_EXT_REG_BASE), called IO domain power control register. And that Thanks, Vaibhav