From patchwork Wed Mar 2 15:32:07 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lee Jones X-Patchwork-Id: 591014 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id D0842140B0F for ; Thu, 3 Mar 2016 02:35:00 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.b=LFRdzAt6; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753479AbcCBPeq (ORCPT ); Wed, 2 Mar 2016 10:34:46 -0500 Received: from mail-wm0-f50.google.com ([74.125.82.50]:34447 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755192AbcCBPee (ORCPT ); Wed, 2 Mar 2016 10:34:34 -0500 Received: by mail-wm0-f50.google.com with SMTP id p65so85403949wmp.1 for ; Wed, 02 Mar 2016 07:34:28 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=sG0DMqMVuaNXG9PKwh9NX1JqEATmHKJVnLG4blCDOQU=; b=LFRdzAt6NipX2fKKNFraCiWbGAK/NcHtpgW3C4T54hehMjpiUAC4U3oU2qKcAMOn3h hPgPgjIkUx/uegzIILxmSDGHcGx8DjS5Ro6PRQtaTMNJgJEtqHd7svKyvO7tvvyN4hCl IDYHEYOfidF+bT51eeux5igvsTwOYpAvMlXsg= 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:in-reply-to :references; bh=sG0DMqMVuaNXG9PKwh9NX1JqEATmHKJVnLG4blCDOQU=; b=DactMc7kPiBiRXHoouRi85JHSEZBgkcQTJBwJSmSGtbPNj0TmdgAirrv1MO2XDGppW QimzikD4Y690O8ruAxxob+5BvVo3TXW9kHYI6kVaAt26gOx6X3nl21pIqWWr5bEEYrTY jFvifyn7GKWzGi8M5A7WGtGjrHkBytFtfeKf94RjuhptGIQO+TWQ9Oey142idGBLRi1O LC7ZFfyBP4xywyBpGH8YgaheDQws+Yn6GZeeIHpUt+OBI/q1Xn+I90Zvju4ZUunOjQ/z MbN0U1jnEJmR7yrFVGOJJu+qYN9IJJGcDMsIHXLYN58yXigWdj6S7JZvpwby23PJRZDP /67Q== X-Gm-Message-State: AD7BkJJM1RDux8LjT/b3SUF4BMOIK6aYbdzPpAX8r6Q+2LsuAt19wPZDhcWL7Pldt/mrXpmk X-Received: by 10.28.21.149 with SMTP id 143mr511824wmv.86.1456932863208; Wed, 02 Mar 2016 07:34:23 -0800 (PST) Received: from localhost.localdomain (host81-154-142-245.range81-154.btcentralplus.com. [81.154.142.245]) by smtp.gmail.com with ESMTPSA id da6sm26941407wjb.24.2016.03.02.07.34.22 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 02 Mar 2016 07:34:22 -0800 (PST) From: Lee Jones To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: kernel@stlinux.com, maxime.coquelin@st.com, thierry.reding@gmail.com, linux-pwm@vger.kernel.org, ajitpal.singh@st.com, Lee Jones Subject: [RESEND 09/11] pwm: sti: Add PWM Capture call-back Date: Wed, 2 Mar 2016 15:32:07 +0000 Message-Id: <1456932729-9667-10-git-send-email-lee.jones@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1456932729-9667-1-git-send-email-lee.jones@linaro.org> References: <1456932729-9667-1-git-send-email-lee.jones@linaro.org> Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org Once a PWM Capture has been initiated, the capture call enables a rising edge detection IRQ, then waits. Once each of the 3 phase changes have been recorded the thread then wakes. The remaining part of the call carries out the relevant calculations and passes back a formatted string to the caller. Signed-off-by: Lee Jones --- drivers/pwm/pwm-sti.c | 72 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 72 insertions(+) diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c index 82a69e4..8de9b4a 100644 --- a/drivers/pwm/pwm-sti.c +++ b/drivers/pwm/pwm-sti.c @@ -309,7 +309,79 @@ static void sti_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) clear_bit(pwm->hwpwm, &pc->configured); } +static int sti_pwm_capture(struct pwm_chip *chip, struct pwm_device *pwm, + int channel, char *buf) +{ + struct sti_pwm_chip *pc = to_sti_pwmchip(chip); + struct sti_pwm_compat_data *cdata = pc->cdata; + struct sti_cpt_data *d = pc->cpt_data[channel]; + struct device *dev = pc->dev; + unsigned int f, dc; + unsigned int high, low; + bool level; + int ret; + + if (channel > cdata->cpt_num_chan - 1) { + dev_err(dev, "Channel %d is not valid\n", channel); + return -EINVAL; + } + + mutex_lock(&d->lock); + + /* Prepare capture measurement */ + d->index = 0; + regmap_write(pc->regmap, PWM_CPT_EDGE(channel), CPT_EDGE_RISING); + regmap_field_write(pc->pwm_cpt_int_en, BIT(channel)); + ret = wait_event_interruptible_timeout(d->wait, d->index > 1, HZ); + + /* + * In case we woke up for another reason than completion + * make sure to disable the capture. + */ + regmap_write(pc->regmap, PWM_CPT_EDGE(channel), CPT_EDGE_DISABLED); + + if (ret == -ERESTARTSYS) + goto out; + + switch (d->index) { + case 0: + case 1: + /* + * Getting here could mean : + * - input signal is constant of less than 1Hz + * - there is no input signal at all + * + * In such case the frequency is rounded down to 0 + * level of the supposed constant signal is reported + * using duty cycle min and max values. + */ + level = gpio_get_value(d->gpio); + + ret = sprintf(buf, "0:%u\n", level ? CPT_DC_MAX : 0); + break; + case 2: + /* We have evertying we need */ + high = d->snapshot[1] - d->snapshot[0]; + low = d->snapshot[2] - d->snapshot[1]; + + /* Calculate frequency in Hz */ + f = clk_get_rate(pc->cpt_clk) / (1 * (high + low)); + + /* Calculate the duty cycle */ + dc = CPT_DC_MAX * high / (high + low); + + ret = sprintf(buf, "%u:%u\n", f, dc); + default: + dev_err(dev, "Internal error\n"); + } + +out: + mutex_unlock(&d->lock); + return ret; +} + static const struct pwm_ops sti_pwm_ops = { + .capture = sti_pwm_capture, .config = sti_pwm_config, .enable = sti_pwm_enable, .disable = sti_pwm_disable,