From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rajkumar Rampelli Subject: [PATCH V2 7/9] hwmon: pwm-fan: add sysfs node to read rpm of fan Date: Wed, 21 Mar 2018 10:10:42 +0530 Message-ID: <1521607244-29734-8-git-send-email-rrajk@nvidia.com> References: <1521607244-29734-1-git-send-email-rrajk@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1521607244-29734-1-git-send-email-rrajk@nvidia.com> Sender: linux-kernel-owner@vger.kernel.org To: robh+dt@kernel.org, mark.rutland@arm.com, thierry.reding@gmail.com, jonathanh@nvidia.com, jdelvare@suse.com, linux@roeck-us.net, corbet@lwn.net, catalin.marinas@arm.com, will.deacon@arm.com, kstewart@linuxfoundation.org, gregkh@linuxfoundation.org, pombredanne@nexb.com, mmaddireddy@nvidia.com, mperttunen@nvidia.com, arnd@arndb.de, timur@codeaurora.org, andy.gross@linaro.org, xuwei5@hisilicon.com, elder@linaro.org, heiko@sntech.de, krzk@kernel.org, ard.biesheuvel@linaro.org Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pwm@vger.kernel.org, linux-tegra@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-doc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, ldewangan@nvidia.com, rrajk@nvidia.com List-Id: devicetree@vger.kernel.org Add fan device attribute fan1_input in pwm-fan driver to read speed of fan in rotations per minute. Signed-off-by: Rajkumar Rampelli --- V2: Removed generic-pwm-tachometer driver and using pwm-fan driver as per suggestions to read fan speed. Added fan device attribute to report speed of fan in rpms through hwmon sysfs. drivers/hwmon/pwm-fan.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c index 70cc0d1..8dda209 100644 --- a/drivers/hwmon/pwm-fan.c +++ b/drivers/hwmon/pwm-fan.c @@ -98,11 +98,34 @@ static ssize_t show_pwm(struct device *dev, return sprintf(buf, "%u\n", ctx->pwm_value); } +static ssize_t show_rpm(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct pwm_fan_ctx *ptt = dev_get_drvdata(dev); + struct pwm_device *pwm = ptt->pwm; + struct pwm_capture result; + unsigned int rpm = 0; + int ret; + + ret = pwm_capture(pwm, &result, 0); + if (ret < 0) { + pr_err("Failed to capture PWM: %d\n", ret); + return ret; + } + + if (result.period) + rpm = DIV_ROUND_CLOSEST_ULL(60ULL * NSEC_PER_SEC, + result.period); + + return sprintf(buf, "%u\n", rpm); +} static SENSOR_DEVICE_ATTR(pwm1, S_IRUGO | S_IWUSR, show_pwm, set_pwm, 0); +static SENSOR_DEVICE_ATTR(fan1_input, 0444, show_rpm, NULL, 0); static struct attribute *pwm_fan_attrs[] = { &sensor_dev_attr_pwm1.dev_attr.attr, + &sensor_dev_attr_fan1_input.dev_attr.attr, NULL, }; -- 2.1.4