From patchwork Mon Dec 15 23:25:27 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Doug Anderson X-Patchwork-Id: 5498361 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id D95D79F30B for ; Mon, 15 Dec 2014 23:27:58 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D77A12096B for ; Mon, 15 Dec 2014 23:27:57 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id D891320A14 for ; Mon, 15 Dec 2014 23:27:56 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1Y0f1o-0003Qt-UF; Mon, 15 Dec 2014 23:26:12 +0000 Received: from mail-ig0-x22f.google.com ([2607:f8b0:4001:c05::22f]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1Y0f1h-0003Fj-UQ for linux-arm-kernel@lists.infradead.org; Mon, 15 Dec 2014 23:26:07 +0000 Received: by mail-ig0-f175.google.com with SMTP id h15so5941639igd.8 for ; Mon, 15 Dec 2014 15:25:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id; bh=c9xW4+cAKtnVAIuuK6vx4latB9GKhpvbpXPG0eDcc3w=; b=IOaj811lxQekXFhzJ2a4q6itxTzqRPXDwWN2w0LRJDHk4c1seHZRgdpjIJ1WYK3lZT gxsIRNP+Cf5vNu3g91PGzlI0/hxCt2XDMiqbk95IA+71StNTObmDRRP3KT3evkz03Po+ Uw93suQOXz0kWxVGj+eUve3gd8CzJ6JljUsas= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=c9xW4+cAKtnVAIuuK6vx4latB9GKhpvbpXPG0eDcc3w=; b=UroKyT/919tLfFzT/Zi/ga0fRinJKrqCneEN37OvYnnRi8NSvbbLMMLcnzzOQbAT+q CbvCwnDJccSFkspXgo/WlufrZcST1ZcEj+PXiNKICXVjDYlipaXgLtYwwJMM92b7IH/D t6Aljx6YgC+pQ91NopvA++/JeoAbsC1Lb9G1QjWG1GaNhAt7Pi60tQeC874HwpJ6A3Pq EfqZGucbe1XcaGImCLlHNPWqjDJyQROEdQSyj7ODkTB5zb8Dl9xM8W5WZS5GxegVaJRh bPRkgoDR2kOGHXC7oOlxl6zn9R7dipHEkN6IpJ/x0bFx0WOpJfbehbAy9gifkF52Kz3O ybdg== X-Gm-Message-State: ALoCoQkMmoHX6fpDNx8ZamwsPCkm8azLYo/YwC/r1oZOCh0CcISNd9ApRRSdNqI+TA+mUmKQ3ufQ X-Received: by 10.50.112.165 with SMTP id ir5mr20452567igb.44.1418685943943; Mon, 15 Dec 2014 15:25:43 -0800 (PST) Received: from tictac.mtv.corp.google.com ([172.22.65.76]) by mx.google.com with ESMTPSA id uw1sm11999igb.19.2014.12.15.15.25.42 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 15 Dec 2014 15:25:43 -0800 (PST) From: Doug Anderson To: Ulf Hansson , Heiko Stuebner , Jaehoon Chung , Seungwon Jeon Subject: [PATCH v2 1/3] mmc: core: Add mmc_regulator_set_vqmmc() Date: Mon, 15 Dec 2014 15:25:27 -0800 Message-Id: <1418685929-13096-1-git-send-email-dianders@chromium.org> X-Mailer: git-send-email 2.2.0.rc0.207.ga3a616c X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141215_152606_078601_CFF3E51B X-CRM114-Status: GOOD ( 15.31 ) X-Spam-Score: -0.8 (/) Cc: andrew_gabbasov@mentor.com, Alexandru Stan , Andrew Bresticker , linux-kernel@vger.kernel.org, linux-mmc@vger.kernel.org, Doug Anderson , chris@printf.net, linux-rockchip@lists.infradead.org, Mark Brown , tim.kryger@gmail.com, Alim Akhtar , adrian.hunter@intel.com, Sonny Rao , johan.rudholm@axis.com, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_MED, T_DKIM_INVALID, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This adds logic to the MMC core to set VQMMC. This is expected to be called by MMC drivers like dw_mmc as part of (or instead of) their start_signal_voltage_switch() callback. A few notes: * When setting the signal voltage to 3.3V we do our best to make VQMMC and VMMC match. It's been reported that this makes some old cards happy since they were tested back in the day before UHS when VQMMC and VMMC were provided by the same regulator. A nice side effect of this is that we don't end up on the hairy edge of VQMMC (2.7V), which some EEs claim is a little too close to the minimum for comfort. * When setting the signal voltage to 1.8V or 1.2V we aim for that specific voltage instead of picking the lowest one in the range. * We very purposely don't print errors in mmc_regulator_set_vqmmc(). There are cases where the MMC core will try several different voltages and we don't want to pollute the logs. Signed-off-by: Doug Anderson Reviewed-by: Andrew Bresticker --- Changes in v2: - Now use existing regulator_set_voltage_tol() function. drivers/mmc/core/core.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/mmc/host.h | 7 +++++++ 2 files changed, 58 insertions(+) diff --git a/drivers/mmc/core/core.c b/drivers/mmc/core/core.c index 9584bff..670dc65 100644 --- a/drivers/mmc/core/core.c +++ b/drivers/mmc/core/core.c @@ -1333,6 +1333,57 @@ int mmc_regulator_set_ocr(struct mmc_host *mmc, } EXPORT_SYMBOL_GPL(mmc_regulator_set_ocr); +static int mmc_regulator_set_voltage_if_supported(struct regulator *regulator, + int new_uV, int tol_uV) +{ + /* + * Check if supported first to avoid errors since we may try several + * signal levels during power up and don't want to show errors. + */ + if (!regulator_is_supported_voltage_tol(regulator, new_uV, tol_uV)) + return -EINVAL; + + return regulator_set_voltage_tol(regulator, new_uV, tol_uV); +} + +/** + * mmc_regulator_set_vqmmc - Set VQMMC as per the ios + * + * For 3.3V signaling, we try to match VQMMC to VMMC as closely as possible. + * That will match the behavior of old boards where VQMMC and VMMC were supplied + * by the same supply. The Bus Operating conditions for 3.3V signaling in the + * SD card spec also define VQMMC in terms of VMMC. + * + * For 1.2V and 1.8V signaling we'll try to get as close as possible to the + * requested voltage. This is definitely a good idea for UHS where there's a + * separate regulator on the card that's trying to make 1.8V and it's best if + * we match. + * + * This function is expected to be used by a controller's + * start_signal_voltage_switch() function. + */ +int mmc_regulator_set_vqmmc(struct mmc_host *mmc, struct mmc_ios *ios) +{ + /* If no vqmmc supply then we can't change the voltage */ + if (IS_ERR(mmc->supply.vqmmc)) + return -EINVAL; + + switch (ios->signal_voltage) { + case MMC_SIGNAL_VOLTAGE_120: + return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc, + 1200000, 100000); + case MMC_SIGNAL_VOLTAGE_180: + return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc, + 1800000, 100000); + case MMC_SIGNAL_VOLTAGE_330: + return mmc_regulator_set_voltage_if_supported(mmc->supply.vqmmc, + regulator_get_voltage(mmc->supply.vmmc), 300000); + default: + return -EINVAL; + } +} +EXPORT_SYMBOL_GPL(mmc_regulator_set_vqmmc); + #endif /* CONFIG_REGULATOR */ int mmc_regulator_get_supply(struct mmc_host *mmc) diff --git a/include/linux/mmc/host.h b/include/linux/mmc/host.h index 9f32270..524d6fc 100644 --- a/include/linux/mmc/host.h +++ b/include/linux/mmc/host.h @@ -416,6 +416,7 @@ int mmc_regulator_get_ocrmask(struct regulator *supply); int mmc_regulator_set_ocr(struct mmc_host *mmc, struct regulator *supply, unsigned short vdd_bit); +int mmc_regulator_set_vqmmc(struct mmc_host *mmc, struct mmc_ios *ios); #else static inline int mmc_regulator_get_ocrmask(struct regulator *supply) { @@ -428,6 +429,12 @@ static inline int mmc_regulator_set_ocr(struct mmc_host *mmc, { return 0; } + +static inline int mmc_regulator_set_vqmmc(struct mmc_host *mmc, + struct mmc_ios *ios) +{ + return -EINVAL; +} #endif int mmc_regulator_get_supply(struct mmc_host *mmc);