From patchwork Tue Aug 16 09:35:05 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lee Jones X-Patchwork-Id: 659576 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 3sD6hd5pTyz9t1j for ; Tue, 16 Aug 2016 19:37:21 +1000 (AEST) Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=linaro.org header.i=@linaro.org header.b=F4CddpQl; dkim-atps=neutral Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753773AbcHPJhA (ORCPT ); Tue, 16 Aug 2016 05:37:00 -0400 Received: from mail-wm0-f43.google.com ([74.125.82.43]:38375 "EHLO mail-wm0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753620AbcHPJfx (ORCPT ); Tue, 16 Aug 2016 05:35:53 -0400 Received: by mail-wm0-f43.google.com with SMTP id o80so154619443wme.1 for ; Tue, 16 Aug 2016 02:35:52 -0700 (PDT) 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=R3/nx2PYzJt538CWqFtXKUhaFv0LbiWC4HGIJEVywEs=; b=F4CddpQlIhEx3mI1XMEN8zSV0ZI4c+kDa+mtOFORFB0yt7PsiFcGUcwE5X1xUM8+yp SrXhbR5QFdHcswPjUesxuaWwUcbJ+0TApXIBhyW5q7fFxyDkVBBWuJaobjVByeBlQov5 Iht3dtmDMt6kUb7T9ioA/JfbwD4utmfVzEHnE= 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=R3/nx2PYzJt538CWqFtXKUhaFv0LbiWC4HGIJEVywEs=; b=PxfiJ4wZtwMli2WNRId2gcojr9WPTO8EhNi/TpNj1rC2U/5uVhyuwbvMOOh9VNwtVj BoS0UAFb1LoRSGmcGckoidGPMFBGNwcrhNIRmRofFPUtUu+3LeutuqqHWQ69yomKYhE0 WunCi+yVPmuMh0gQHES7K8q4Dup4ZgfR8xuqsNLv/P2k8GxV6oP6AxONAzgeI+N5mFCx 5YgGeNYSz177T2goZl3RDE5MWuToirK1a8vsOaEtEMn3/W60mVB5lW+zVtkpbu2ZHgXL ZtWcagVpSRnOZuXhf9meSmzRqPyuBAp89XwoLwYm4JNaE32B5cCOVKSZ+kF9hasX9Tbs AZkA== X-Gm-Message-State: AEkooutyEgedvxvZCqnz0+o2E40HzxtwKCZyvRzqwiS7xZFzMPc72PytBsvl4BwRgXXWqyJh X-Received: by 10.28.113.151 with SMTP id d23mr21557239wmi.89.1471340152057; Tue, 16 Aug 2016 02:35:52 -0700 (PDT) Received: from localhost.localdomain (host81-129-169-93.range81-129.btcentralplus.com. [81.129.169.93]) by smtp.gmail.com with ESMTPSA id g1sm16614889wjy.5.2016.08.16.02.35.51 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 16 Aug 2016 02:35:51 -0700 (PDT) From: Lee Jones To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: kernel@stlinux.com, patrice.chotard@st.com, thierry.reding@gmail.com, linux-pwm@vger.kernel.org, devicetree@vger.kernel.org, Lee Jones Subject: [PATCH v4 14/17] pwm: sti: Add PWM Capture call-back Date: Tue, 16 Aug 2016 10:35:05 +0100 Message-Id: <20160816093508.28307-15-lee.jones@linaro.org> X-Mailer: git-send-email 2.9.0 In-Reply-To: <20160816093508.28307-1-lee.jones@linaro.org> References: <20160816093508.28307-1-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 | 88 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 88 insertions(+) diff --git a/drivers/pwm/pwm-sti.c b/drivers/pwm/pwm-sti.c index 4686ba0..fcc80eb 100644 --- a/drivers/pwm/pwm-sti.c +++ b/drivers/pwm/pwm-sti.c @@ -24,6 +24,8 @@ #include #include +#define SECS_TO_NANOSECS(x) ((x) * 1000 * 1000 * 1000) + #define PWM_OUT_VAL(x) (0x00 + (4 * (x))) /* Device's Duty Cycle register */ #define PWM_CPT_VAL(x) (0x10 + (4 * (x))) /* Capture value */ #define PWM_CPT_EDGE(x) (0x30 + (4 * (x))) /* Edge to capture on */ @@ -305,7 +307,88 @@ 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, + struct pwm_capture *result, unsigned long timeout) +{ + struct sti_pwm_chip *pc = to_sti_pwmchip(chip); + struct sti_pwm_compat_data *cdata = pc->cdata; + struct sti_cpt_ddata *ddata = pwm_get_chip_data(pwm); + struct device *dev = pc->dev; + unsigned int effective_ticks; + unsigned long long high, low; + int ret; + + if (pwm->hwpwm > cdata->cpt_num_devs - 1) { + dev_err(dev, "Device %d is not valid\n", pwm->hwpwm); + return -EINVAL; + } + + mutex_lock(&ddata->lock); + + /* Prepare capture measurement */ + ddata->index = 0; + regmap_write(pc->regmap, PWM_CPT_EDGE(pwm->hwpwm), CPT_EDGE_RISING); + regmap_field_write(pc->pwm_cpt_int_en, BIT(pwm->hwpwm)); + + /* Enable capture */ + ret = regmap_field_write(pc->pwm_cpt_en, 1); + if (ret) { + dev_err(dev, "failed to enable PWM capture %d\n", pwm->hwpwm); + goto out; + } + + ret = wait_event_interruptible_timeout(ddata->wait, + ddata->index > 1, + msecs_to_jiffies(timeout)); + + regmap_write(pc->regmap, PWM_CPT_EDGE(pwm->hwpwm), CPT_EDGE_DISABLED); + + if (ret == -ERESTARTSYS) + goto out; + + switch (ddata->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 + */ + + result->period = 0; + result->duty_cycle = 0; + + break; + case 2: + /* We have everying we need */ + high = ddata->snapshot[1] - ddata->snapshot[0]; + low = ddata->snapshot[2] - ddata->snapshot[1]; + + effective_ticks = clk_get_rate(pc->cpt_clk); + + result->period = SECS_TO_NANOSECS(high + low); + result->period /= effective_ticks; + + result->duty_cycle = SECS_TO_NANOSECS(high); + result->duty_cycle /= effective_ticks; + + break; + default: + dev_err(dev, "Internal error\n"); + } + +out: + /* Disable capture */ + regmap_field_write(pc->pwm_cpt_en, 0); + + mutex_unlock(&ddata->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, @@ -418,6 +501,11 @@ static int sti_pwm_probe_dt(struct sti_pwm_chip *pc) if (IS_ERR(pc->pwm_out_en)) return PTR_ERR(pc->pwm_out_en); + pc->pwm_cpt_en = devm_regmap_field_alloc(dev, pc->regmap, + reg_fields[PWM_CPT_EN]); + if (IS_ERR(pc->pwm_cpt_en)) + return PTR_ERR(pc->pwm_cpt_en); + pc->pwm_cpt_int_en = devm_regmap_field_alloc(dev, pc->regmap, reg_fields[PWM_CPT_INT_EN]); if (IS_ERR(pc->pwm_cpt_int_en))