From mboxrd@z Thu Jan 1 00:00:00 1970 From: Adrian Hunter Subject: Re: [PATCH 1/3] mmc: sdhci-sprd: Add start_signal_voltage_switch ops Date: Mon, 1 Jul 2019 16:31:18 +0300 Message-ID: <09a99609-9126-1df5-5ec4-bffe65daeca6@intel.com> References: <89fb15e88f33a3c1ce7b5eefa9414a20c984c579.1561094029.git.baolin.wang@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <89fb15e88f33a3c1ce7b5eefa9414a20c984c579.1561094029.git.baolin.wang@linaro.org> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Baolin Wang , ulf.hansson@linaro.org, zhang.lyra@gmail.com, orsonzhai@gmail.com, robh+dt@kernel.org, mark.rutland@arm.com Cc: vincent.guittot@linaro.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org On 21/06/19 9:12 AM, Baolin Wang wrote: > For Spreadtrum SD host controller, we can not use standard SD registers > to change and detect the I/O voltage signals, since our voltage regulator > for I/O is fixed in hardware, and no signals were connected to the SD > controller. Thus add Spreadtrum specific voltage switch ops to change > voltage instead of using standard SD host registers. > > Signed-off-by: Baolin Wang Acked-by: Adrian Hunter > --- > drivers/mmc/host/sdhci-sprd.c | 24 ++++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > diff --git a/drivers/mmc/host/sdhci-sprd.c b/drivers/mmc/host/sdhci-sprd.c > index 024c3c5..8b23c88 100644 > --- a/drivers/mmc/host/sdhci-sprd.c > +++ b/drivers/mmc/host/sdhci-sprd.c > @@ -403,6 +403,22 @@ static void sdhci_sprd_request(struct mmc_host *mmc, struct mmc_request *mrq) > sdhci_request(mmc, mrq); > } > > +static int sdhci_sprd_voltage_switch(struct mmc_host *mmc, struct mmc_ios *ios) > +{ > + int ret; > + > + if (!IS_ERR(mmc->supply.vqmmc)) { > + ret = mmc_regulator_set_vqmmc(mmc, ios); > + if (ret) { > + pr_err("%s: Switching signalling voltage failed\n", > + mmc_hostname(mmc)); > + return ret; > + } > + } > + > + return 0; > +} > + > static void sdhci_sprd_hs400_enhanced_strobe(struct mmc_host *mmc, > struct mmc_ios *ios) > { > @@ -470,6 +486,14 @@ static int sdhci_sprd_probe(struct platform_device *pdev) > host->mmc_host_ops.request = sdhci_sprd_request; > host->mmc_host_ops.hs400_enhanced_strobe = > sdhci_sprd_hs400_enhanced_strobe; > + /* > + * We can not use the standard ops to change and detect the voltage > + * signal for Spreadtrum SD host controller, since our voltage regulator > + * for I/O is fixed in hardware, that means we do not need control > + * the standard SD host controller to change the I/O voltage. > + */ > + host->mmc_host_ops.start_signal_voltage_switch = > + sdhci_sprd_voltage_switch; > > host->mmc->caps = MMC_CAP_SD_HIGHSPEED | MMC_CAP_MMC_HIGHSPEED | > MMC_CAP_ERASE | MMC_CAP_CMD23; >