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[67.161.204.6]) by smtp.gmail.com with ESMTPSA id b132sm778343iob.6.2017.03.29.20.46.47 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 29 Mar 2017 20:46:47 -0700 (PDT) From: Sam Povilus To: wsa@the-dreams.de, jdelvare@suse.com, linux@roeck-us.net, linux-hwmon@vger.kernel.org, linux-i2c@vger.kernel.org, devicetree@vger.kernel.org, robh+dt@kernel.org, mark.rutland@arm.com Cc: Sam Povilus Subject: [PATCH v6] hwmon: ads7828 optional parameters from the device tree Date: Wed, 29 Mar 2017 21:46:37 -0600 Message-Id: <20170330034637.29708-1-kernel.development@povil.us> X-Mailer: git-send-email 2.11.0 Sender: devicetree-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org Adding the ability for the ads7828 and ads7830 to use the device tree to get their optional parameters, instead of using platform devices. This allows people using custom boards to also use the ads7828 in a non-default manner. v2: conforming to coding style v3: changing from "_" to "-" for device tree entries v4: using regulator subsystem for voltage source, renaming differential input property v5: checking for invalid vref values sooner and returning error if they are bad, not warning user. v6: optimization per Guenter Roeck Signed-off-by: Sam Povilus --- .../devicetree/bindings/hwmon/ads7828.txt | 26 ++++++++++++++++++++++ drivers/hwmon/ads7828.c | 15 +++++++++++++ 2 files changed, 41 insertions(+) create mode 100644 Documentation/devicetree/bindings/hwmon/ads7828.txt diff --git a/Documentation/devicetree/bindings/hwmon/ads7828.txt b/Documentation/devicetree/bindings/hwmon/ads7828.txt new file mode 100644 index 000000000000..a1251b19079d --- /dev/null +++ b/Documentation/devicetree/bindings/hwmon/ads7828.txt @@ -0,0 +1,26 @@ +ads7828 properties + +Required properties: +- compatible: Should be one of + ti,ads7828 + ti,ads7830 +- reg: I2C address + +Optional properties: + +- ti,differential-input + Set to use the device in differential mode. +- vref + The external reference on the device is set to this regulators output. If it + does not exists the internal reference will be used and output by the ads78xx + on the "external vref" pin. + + Example ADS7828 node: + + ads7828: ads@48 { + comatible = "ti,ads7828"; + reg = <0x48>; + vref-supply = <&vref>; + ti,differential-input; + }; + diff --git a/drivers/hwmon/ads7828.c b/drivers/hwmon/ads7828.c index ee396ff167d9..88330a233b1d 100644 --- a/drivers/hwmon/ads7828.c +++ b/drivers/hwmon/ads7828.c @@ -34,6 +34,7 @@ #include #include #include +#include /* The ADS7828 registers */ #define ADS7828_CMD_SD_SE 0x80 /* Single ended inputs */ @@ -118,9 +119,11 @@ static int ads7828_probe(struct i2c_client *client, struct ads7828_data *data; struct device *hwmon_dev; unsigned int vref_mv = ADS7828_INT_VREF_MV; + unsigned int vref_uv; bool diff_input = false; bool ext_vref = false; unsigned int regval; + struct regulator *reg; data = devm_kzalloc(dev, sizeof(struct ads7828_data), GFP_KERNEL); if (!data) @@ -131,6 +134,18 @@ static int ads7828_probe(struct i2c_client *client, ext_vref = pdata->ext_vref; if (ext_vref && pdata->vref_mv) vref_mv = pdata->vref_mv; + } else if (dev->of_node) { + diff_input = of_property_read_bool(dev->of_node, + "ti,differential-input"); + reg = devm_regulator_get_optional(dev, "vref"); + if (!IS_ERR(reg)) { + vref_uv = regulator_get_voltage(reg); + vref_mv = DIV_ROUND_CLOSEST(vref_uv, 1000); + if (vref_mv < ADS7828_EXT_VREF_MV_MIN || + vref_mv > ADS7828_EXT_VREF_MV_MAX) + return -EINVAL; + ext_vref = true; + } } /* Bound Vref with min/max values */