From patchwork Thu Jan 29 15:00:06 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Javier Martinez Canillas X-Patchwork-Id: 5743151 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 71DFABF440 for ; Thu, 29 Jan 2015 15:03:07 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 723F82025B for ; Thu, 29 Jan 2015 15:03:06 +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 52F6020254 for ; Thu, 29 Jan 2015 15:03:05 +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 1YGqax-00055m-VC; Thu, 29 Jan 2015 15:01:23 +0000 Received: from bhuna.collabora.co.uk ([93.93.135.160]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1YGqaQ-0004gN-Gj for linux-arm-kernel@lists.infradead.org; Thu, 29 Jan 2015 15:00:51 +0000 Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: javier) with ESMTPSA id CBEF9600E37 From: Javier Martinez Canillas To: Ulf Hansson Subject: [PATCH v3 4/6] mmc: pwrseq_simple: Add optional reference clock support Date: Thu, 29 Jan 2015 16:00:06 +0100 Message-Id: <1422543608-24704-5-git-send-email-javier.martinez@collabora.co.uk> X-Mailer: git-send-email 2.1.3 In-Reply-To: <1422543608-24704-1-git-send-email-javier.martinez@collabora.co.uk> References: <1422543608-24704-1-git-send-email-javier.martinez@collabora.co.uk> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20150129_070050_864182_0AF39A9F X-CRM114-Status: GOOD ( 17.18 ) X-Spam-Score: -0.0 (/) Cc: devicetree@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-mmc@vger.kernel.org, Doug Anderson , linux-kernel@vger.kernel.org, Arend van Spriel , Kukjin Kim , Srinivas Kandagatla , Olof Johansson , Javier Martinez Canillas , 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=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, 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 Some WLAN chips attached to a SDIO interface, need a reference clock. Since this is very common, extend the prseq_simple driver to support an optional clock that is enabled prior the card power up procedure. Note: the external clock is optional. Thus an error is not returned if the clock is not found. Signed-off-by: Javier Martinez Canillas --- Changes since v2: - Add a clk_enabled bool to struct mmc_pwrseq_simple to track clock gate/ungate since .power_off can be called prior to .pre_power_on. Suggested by Ulf Hansson. - clk_get() does not return -ENOSYS so don't check for that. Suggested by Ulf Hansson. Changes since v1: - Rebase on top of latest changes. - Use IS_ERR() instead of checking for NULL to see if the clock exists. --- drivers/mmc/core/pwrseq_simple.c | 38 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 36 insertions(+), 2 deletions(-) diff --git a/drivers/mmc/core/pwrseq_simple.c b/drivers/mmc/core/pwrseq_simple.c index e53d3c7e059c..50d09d920430 100644 --- a/drivers/mmc/core/pwrseq_simple.c +++ b/drivers/mmc/core/pwrseq_simple.c @@ -7,6 +7,7 @@ * * Simple MMC power sequence management */ +#include #include #include #include @@ -20,6 +21,8 @@ struct mmc_pwrseq_simple { struct mmc_pwrseq pwrseq; + bool clk_enabled; + struct clk *ext_clk; int nr_gpios; struct gpio_desc *reset_gpios[0]; }; @@ -39,6 +42,11 @@ static void mmc_pwrseq_simple_pre_power_on(struct mmc_host *host) struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq, struct mmc_pwrseq_simple, pwrseq); + if (!IS_ERR(pwrseq->ext_clk)) { + clk_prepare_enable(pwrseq->ext_clk); + pwrseq->clk_enabled = true; + } + mmc_pwrseq_simple_set_gpios_value(pwrseq, 1); } @@ -50,6 +58,19 @@ static void mmc_pwrseq_simple_post_power_on(struct mmc_host *host) mmc_pwrseq_simple_set_gpios_value(pwrseq, 0); } +static void mmc_pwrseq_simple_power_off(struct mmc_host *host) +{ + struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq, + struct mmc_pwrseq_simple, pwrseq); + + mmc_pwrseq_simple_set_gpios_value(pwrseq, 1); + + if (pwrseq->clk_enabled) { + clk_disable_unprepare(pwrseq->ext_clk); + pwrseq->clk_enabled = false; + } +} + static void mmc_pwrseq_simple_free(struct mmc_host *host) { struct mmc_pwrseq_simple *pwrseq = container_of(host->pwrseq, @@ -60,6 +81,9 @@ static void mmc_pwrseq_simple_free(struct mmc_host *host) if (!IS_ERR(pwrseq->reset_gpios[i])) gpiod_put(pwrseq->reset_gpios[i]); + if (!IS_ERR(pwrseq->ext_clk)) + clk_put(pwrseq->ext_clk); + kfree(pwrseq); host->pwrseq = NULL; } @@ -67,7 +91,7 @@ static void mmc_pwrseq_simple_free(struct mmc_host *host) static struct mmc_pwrseq_ops mmc_pwrseq_simple_ops = { .pre_power_on = mmc_pwrseq_simple_pre_power_on, .post_power_on = mmc_pwrseq_simple_post_power_on, - .power_off = mmc_pwrseq_simple_pre_power_on, + .power_off = mmc_pwrseq_simple_power_off, .free = mmc_pwrseq_simple_free, }; @@ -85,6 +109,13 @@ int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev) if (!pwrseq) return -ENOMEM; + pwrseq->ext_clk = clk_get(dev, "ext_clock"); + if (IS_ERR(pwrseq->ext_clk) && + PTR_ERR(pwrseq->ext_clk) != -ENOENT) { + ret = PTR_ERR(pwrseq->ext_clk); + goto free; + } + for (i = 0; i < nr_gpios; i++) { pwrseq->reset_gpios[i] = gpiod_get_index(dev, "reset", i, GPIOD_OUT_HIGH); @@ -96,7 +127,7 @@ int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev) while (--i) gpiod_put(pwrseq->reset_gpios[i]); - goto free; + goto clk_put; } } @@ -105,6 +136,9 @@ int mmc_pwrseq_simple_alloc(struct mmc_host *host, struct device *dev) host->pwrseq = &pwrseq->pwrseq; return 0; +clk_put: + if (!IS_ERR(pwrseq->ext_clk)) + clk_put(pwrseq->ext_clk); free: kfree(pwrseq); return ret;