From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vijay Viswanath Subject: Re: [PATCH V1 1/3] mmc: sdhci: Allow platform controlled voltage switching Date: Wed, 25 Jul 2018 17:53:52 +0530 Message-ID: <42ee57f7-8a99-b815-12db-2727ed67872b@codeaurora.org> References: <1532083566-43215-1-git-send-email-vviswana@codeaurora.org> <1532083566-43215-2-git-send-email-vviswana@codeaurora.org> <33e12e51-4b96-032f-845f-7910d654018c@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <33e12e51-4b96-032f-845f-7910d654018c@intel.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Adrian Hunter , ulf.hansson@linaro.org, robh+dt@kernel.org, mark.rutland@arm.com Cc: linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, shawn.lin@rock-chips.com, linux-arm-msm@vger.kernel.org, georgi.djakov@linaro.org, devicetree@vger.kernel.org, asutoshd@codeaurora.org, stummala@codeaurora.org, venkatg@codeaurora.org, jeremymc@redhat.com, bjorn.andersson@linaro.org, riteshh@codeaurora.org, vbadigan@codeaurora.org, evgreen@chromium.org, dianders@google.com, sayalil@codeaurora.org, rampraka@codeaurora.org List-Id: linux-mmc@vger.kernel.org Hi Adrian, On 7/25/2018 5:23 PM, Adrian Hunter wrote: > On 20/07/18 13:46, Vijay Viswanath wrote: >> Some controllers can have internal mechanism to inform the SW that it >> is ready for voltage switching. For such controllers, changing voltage >> before the HW is ready can result in various issues. >> >> During setup/cleanup of host, check whether regulator enable/disable >> was already done by platform driver. >> >> Signed-off-by: Vijay Viswanath >> --- >> drivers/mmc/host/sdhci.c | 21 ++++++++++++++++----- >> 1 file changed, 16 insertions(+), 5 deletions(-) >> >> diff --git a/drivers/mmc/host/sdhci.c b/drivers/mmc/host/sdhci.c >> index 1c828e0..494a1e2 100644 >> --- a/drivers/mmc/host/sdhci.c >> +++ b/drivers/mmc/host/sdhci.c >> @@ -3472,6 +3472,7 @@ int sdhci_setup_host(struct sdhci_host *host) >> unsigned int override_timeout_clk; >> u32 max_clk; >> int ret; >> + bool enable_vqmmc = false; >> >> WARN_ON(host == NULL); >> if (host == NULL) >> @@ -3485,7 +3486,12 @@ int sdhci_setup_host(struct sdhci_host *host) >> * the host can take the appropriate action if regulators are not >> * available. >> */ >> - ret = mmc_regulator_get_supply(mmc); >> + if (!mmc->supply.vmmc) { >> + ret = mmc_regulator_get_supply(mmc); >> + enable_vqmmc = true; >> + } else { >> + ret = 0; >> + } >> if (ret) >> return ret; > > Why not > > if (!mmc->supply.vmmc) { > ret = mmc_regulator_get_supply(mmc); > if (ret) > return ret; > enable_vqmmc = true; > } > looks neater. Will do. >> >> @@ -3736,7 +3742,10 @@ int sdhci_setup_host(struct sdhci_host *host) >> >> /* If vqmmc regulator and no 1.8V signalling, then there's no UHS */ >> if (!IS_ERR(mmc->supply.vqmmc)) { >> - ret = regulator_enable(mmc->supply.vqmmc); >> + if (enable_vqmmc) >> + ret = regulator_enable(mmc->supply.vqmmc); > > Please introduce host->vqmmc_enabled = !ret; > Any reason to introduce vqmmc_enabled variable in sdhci_host structure ? We can get around with a local variable and using regulator_is_enabled API. >> + else >> + ret = 0; >> if (!regulator_is_supported_voltage(mmc->supply.vqmmc, 1700000, >> 1950000)) >> host->caps1 &= ~(SDHCI_SUPPORT_SDR104 | >> @@ -3984,7 +3993,7 @@ int sdhci_setup_host(struct sdhci_host *host) >> return 0; >> >> unreg: >> - if (!IS_ERR(mmc->supply.vqmmc)) >> + if (!IS_ERR(mmc->supply.vqmmc) && enable_vqmmc) > > And just make this > > if (host->vqmmc_enabled) > >> regulator_disable(mmc->supply.vqmmc); >> undma: >> if (host->align_buffer) >> @@ -4002,7 +4011,8 @@ void sdhci_cleanup_host(struct sdhci_host *host) >> { >> struct mmc_host *mmc = host->mmc; >> >> - if (!IS_ERR(mmc->supply.vqmmc)) >> + if (!IS_ERR(mmc->supply.vqmmc) && >> + (regulator_is_enabled(mmc->supply.vqmmc) > 0)) > > if (host->vqmmc_enabled) > >> regulator_disable(mmc->supply.vqmmc); >> >> if (host->align_buffer) >> @@ -4135,7 +4145,8 @@ void sdhci_remove_host(struct sdhci_host *host, int dead) >> >> tasklet_kill(&host->finish_tasklet); >> >> - if (!IS_ERR(mmc->supply.vqmmc)) >> + if (!IS_ERR(mmc->supply.vqmmc) && >> + (regulator_is_enabled(mmc->supply.vqmmc) > 0)) > > if (host->vqmmc_enabled) > >> regulator_disable(mmc->supply.vqmmc); >> >> if (host->align_buffer) >> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-mmc" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Thanks, Vijay