hwmon: DA9055 HWMON driver

This is the HWMON patch for DA9055 PMIC and has got dependency on the
DA9055 MFD core.

This patch monitors the DA9055 PMIC's ADC channels vddout, junction temperature
and auxiliary channels.

This patch is functionally tested on Samsung SMDKV6410.
Signed-off-by: David Dajun Chen <dchen@diasemi.com>
Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
[Guenter Roeck: Dropped __devinit, __devexit, __devexit_p]
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

Documentation/hwmon/da9055

+Supported chips:
+  * Dialog Semiconductors DA9055 PMIC
+    Prefix: 'da9055'
+    Datasheet: Datasheet is not publicly available.
+
+Authors: David Dajun Chen <dchen@diasemi.com>
+
+Description
+-----------
+
+The DA9055 provides an Analogue to Digital Converter (ADC) with 10 bits
+resolution and track and hold circuitry combined with an analogue input
+multiplexer. The analogue input multiplexer will allow conversion of up to 5
+different inputs. The track and hold circuit ensures stable input voltages at
+the input of the ADC during the conversion.
+
+The ADC is used to measure the following inputs:
+Channel 0: VDDOUT - measurement of the system voltage
+Channel 1: ADC_IN1 - high impedance input (0 - 2.5V)
+Channel 2: ADC_IN2 - high impedance input (0 - 2.5V)
+Channel 3: ADC_IN3 - high impedance input (0 - 2.5V)
+Channel 4: Internal Tjunc. - sense (internal temp. sensor)
+
+By using sysfs attributes we can measure the system voltage VDDOUT,
+chip junction temperature and auxiliary channels voltages.
+
+Voltage Monitoring
+------------------
+
+Voltages are sampled in a AUTO mode it can be manually sampled too and results
+are stored in a 10 bit ADC.
+
+The system voltage is calculated as:
+	Milli volt = ((ADC value * 1000) / 85) + 2500
+
+The voltages on ADC channels 1, 2 and 3 are calculated as:
+	Milli volt = (ADC value * 1000) / 102
+
+Temperature Monitoring
+----------------------
+
+Temperatures are sampled by a 10 bit ADC.  Junction temperatures
+are monitored by the ADC channels.
+
+The junction temperature is calculated:
+	Degrees celsius = -0.4084 * (ADC_RES - T_OFFSET) + 307.6332
+The junction temperature attribute is supported by the driver.

drivers/hwmon/Kconfig

@@ -334,6 +334,16 @@ config SENSORS_DA9052_ADC
 	  This driver can also be built as module. If so, the module
 	  will be called da9052-hwmon.
 
+config SENSORS_DA9055
+	tristate "Dialog Semiconductor DA9055 ADC"
+	depends on MFD_DA9055
+	help
+	  If you say yes here you get support for ADC on the Dialog
+	  Semiconductor DA9055 PMIC.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called da9055-hwmon.
+
 config SENSORS_I5K_AMB
 	tristate "FB-DIMM AMB temperature sensor on Intel 5000 series chipsets"
 	depends on PCI

drivers/hwmon/Makefile

@@ -44,6 +44,7 @@ obj-$(CONFIG_SENSORS_ASC7621)	+= asc7621.o
 obj-$(CONFIG_SENSORS_ATXP1)	+= atxp1.o
 obj-$(CONFIG_SENSORS_CORETEMP)	+= coretemp.o
 obj-$(CONFIG_SENSORS_DA9052_ADC)+= da9052-hwmon.o
+obj-$(CONFIG_SENSORS_DA9055)+= da9055-hwmon.o
 obj-$(CONFIG_SENSORS_DME1737)	+= dme1737.o
 obj-$(CONFIG_SENSORS_DS620)	+= ds620.o
 obj-$(CONFIG_SENSORS_DS1621)	+= ds1621.o

drivers/hwmon/da9055-hwmon.c

+/*
+ * HWMON Driver for Dialog DA9055
+ *
+ * Copyright(c) 2012 Dialog Semiconductor Ltd.
+ *
+ * Author: David Dajun Chen <dchen@diasemi.com>
+ *
+ *  This program is free software; you can redistribute  it and/or modify it
+ *  under  the terms of  the GNU General  Public License as published by the
+ *  Free Software Foundation;  either version 2 of the  License, or (at your
+ *  option) any later version.
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/completion.h>
+
+#include <linux/mfd/da9055/core.h>
+#include <linux/mfd/da9055/reg.h>
+
+#define DA9055_ADCIN_DIV	102
+#define DA9055_VSYS_DIV	85
+
+#define DA9055_ADC_VSYS	0
+#define DA9055_ADC_ADCIN1	1
+#define DA9055_ADC_ADCIN2	2
+#define DA9055_ADC_ADCIN3	3
+#define DA9055_ADC_TJUNC	4
+
+struct da9055_hwmon {
+	struct da9055	*da9055;
+	struct device	*class_device;
+	struct mutex	hwmon_lock;
+	struct mutex	irq_lock;
+	struct completion done;
+};
+
+static const char * const input_names[] = {
+	[DA9055_ADC_VSYS]	= "VSYS",
+	[DA9055_ADC_ADCIN1]	= "ADC IN1",
+	[DA9055_ADC_ADCIN2]	= "ADC IN2",
+	[DA9055_ADC_ADCIN3]	= "ADC IN3",
+	[DA9055_ADC_TJUNC]	= "CHIP TEMP",
+};
+
+static const u8 chan_mux[DA9055_ADC_TJUNC + 1] = {
+	[DA9055_ADC_VSYS]	= DA9055_ADC_MUX_VSYS,
+	[DA9055_ADC_ADCIN1]	= DA9055_ADC_MUX_ADCIN1,
+	[DA9055_ADC_ADCIN2]	= DA9055_ADC_MUX_ADCIN2,
+	[DA9055_ADC_ADCIN3]	= DA9055_ADC_MUX_ADCIN1,
+	[DA9055_ADC_TJUNC]	= DA9055_ADC_MUX_T_SENSE,
+};
+
+static int da9055_adc_manual_read(struct da9055_hwmon *hwmon,
+					unsigned char channel)
+{
+	int ret;
+	unsigned short calc_data;
+	unsigned short data;
+	unsigned char mux_sel;
+	struct da9055 *da9055 = hwmon->da9055;
+
+	if (channel > DA9055_ADC_TJUNC)
+		return -EINVAL;
+
+	mutex_lock(&hwmon->irq_lock);
+
+	/* Selects desired MUX for manual conversion */
+	mux_sel = chan_mux[channel] | DA9055_ADC_MAN_CONV;
+
+	ret = da9055_reg_write(da9055, DA9055_REG_ADC_MAN, mux_sel);
+	if (ret < 0)
+		goto err;
+
+	/* Wait for an interrupt */
+	if (!wait_for_completion_timeout(&hwmon->done,
+					msecs_to_jiffies(500))) {
+		dev_err(da9055->dev,
+			"timeout waiting for ADC conversion interrupt\n");
+		ret = -ETIMEDOUT;
+		goto err;
+	}
+
+	ret = da9055_reg_read(da9055, DA9055_REG_ADC_RES_H);
+	if (ret < 0)
+		goto err;
+
+	calc_data = (unsigned short)ret;
+	data = calc_data << 2;
+
+	ret = da9055_reg_read(da9055, DA9055_REG_ADC_RES_L);
+	if (ret < 0)
+		goto err;
+
+	calc_data = (unsigned short)(ret & DA9055_ADC_LSB_MASK);
+	data |= calc_data;
+
+	ret = data;
+
+err:
+	mutex_unlock(&hwmon->irq_lock);
+	return ret;
+}
+
+static irqreturn_t da9055_auxadc_irq(int irq, void *irq_data)
+{
+	struct da9055_hwmon *hwmon = irq_data;
+
+	complete(&hwmon->done);
+
+	return IRQ_HANDLED;
+}
+
+/* Conversion function for VSYS and ADCINx */
+static inline int volt_reg_to_mV(int value, int channel)
+{
+	if (channel == DA9055_ADC_VSYS)
+		return DIV_ROUND_CLOSEST(value * 1000, DA9055_VSYS_DIV) + 2500;
+	else
+		return DIV_ROUND_CLOSEST(value * 1000, DA9055_ADCIN_DIV);
+}
+
+static int da9055_enable_auto_mode(struct da9055 *da9055, int channel)
+{
+
+	return da9055_reg_update(da9055, DA9055_REG_ADC_CONT, 1 << channel,
+				1 << channel);
+
+}
+
+static int da9055_disable_auto_mode(struct da9055 *da9055, int channel)
+{
+
+	return da9055_reg_update(da9055, DA9055_REG_ADC_CONT, 1 << channel, 0);
+}
+
+static ssize_t da9055_read_auto_ch(struct device *dev,
+				struct device_attribute *devattr, char *buf)
+{
+	struct da9055_hwmon *hwmon = dev_get_drvdata(dev);
+	int ret, adc;
+	int channel = to_sensor_dev_attr(devattr)->index;
+
+	mutex_lock(&hwmon->hwmon_lock);
+
+	ret = da9055_enable_auto_mode(hwmon->da9055, channel);
+	if (ret < 0)
+		goto hwmon_err;
+
+	usleep_range(10000, 10500);
+
+	adc = da9055_reg_read(hwmon->da9055, DA9055_REG_VSYS_RES + channel);
+	if (adc < 0) {
+		ret = adc;
+		goto hwmon_err_release;
+	}
+
+	ret = da9055_disable_auto_mode(hwmon->da9055, channel);
+	if (ret < 0)
+		goto hwmon_err;
+
+	mutex_unlock(&hwmon->hwmon_lock);
+
+	return sprintf(buf, "%d\n", volt_reg_to_mV(adc, channel));
+
+hwmon_err_release:
+	da9055_disable_auto_mode(hwmon->da9055, channel);
+hwmon_err:
+	mutex_unlock(&hwmon->hwmon_lock);
+	return ret;
+}
+
+static ssize_t da9055_read_tjunc(struct device *dev,
+				 struct device_attribute *devattr, char *buf)
+{
+	struct da9055_hwmon *hwmon = dev_get_drvdata(dev);
+	int tjunc;
+	int toffset;
+
+	tjunc = da9055_adc_manual_read(hwmon, DA9055_ADC_TJUNC);
+	if (tjunc < 0)
+		return tjunc;
+
+	toffset = da9055_reg_read(hwmon->da9055, DA9055_REG_T_OFFSET);
+	if (toffset < 0)
+		return toffset;
+
+	/*
+	 * Degrees celsius = -0.4084 * (ADC_RES - T_OFFSET) + 307.6332
+	 * T_OFFSET is a trim value used to improve accuracy of the result
+	 */
+	return sprintf(buf, "%d\n", DIV_ROUND_CLOSEST(-4084 * (tjunc - toffset)
+							+ 3076332, 10000));
+}
+
+static ssize_t da9055_hwmon_show_name(struct device *dev,
+				      struct device_attribute *devattr,
+				      char *buf)
+{
+	return sprintf(buf, "da9055-hwmon\n");
+}
+
+static ssize_t show_label(struct device *dev,
+			  struct device_attribute *devattr, char *buf)
+{
+	return sprintf(buf, "%s\n",
+		       input_names[to_sensor_dev_attr(devattr)->index]);
+}
+
+static SENSOR_DEVICE_ATTR(in0_input, S_IRUGO, da9055_read_auto_ch, NULL,
+			  DA9055_ADC_VSYS);
+static SENSOR_DEVICE_ATTR(in0_label, S_IRUGO, show_label, NULL,
+			  DA9055_ADC_VSYS);
+static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, da9055_read_auto_ch, NULL,
+			  DA9055_ADC_ADCIN1);
+static SENSOR_DEVICE_ATTR(in1_label, S_IRUGO, show_label, NULL,
+			  DA9055_ADC_ADCIN1);
+static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, da9055_read_auto_ch, NULL,
+			  DA9055_ADC_ADCIN2);
+static SENSOR_DEVICE_ATTR(in2_label, S_IRUGO, show_label, NULL,
+			  DA9055_ADC_ADCIN2);
+static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, da9055_read_auto_ch, NULL,
+			  DA9055_ADC_ADCIN3);
+static SENSOR_DEVICE_ATTR(in3_label, S_IRUGO, show_label, NULL,
+			  DA9055_ADC_ADCIN3);
+
+static SENSOR_DEVICE_ATTR(temp1_input, S_IRUGO, da9055_read_tjunc, NULL,
+			  DA9055_ADC_TJUNC);
+static SENSOR_DEVICE_ATTR(temp1_label, S_IRUGO, show_label, NULL,
+			  DA9055_ADC_TJUNC);
+
+static DEVICE_ATTR(name, S_IRUGO, da9055_hwmon_show_name, NULL);
+
+static struct attribute *da9055_attr[] = {
+	&dev_attr_name.attr,
+	&sensor_dev_attr_in0_input.dev_attr.attr,
+	&sensor_dev_attr_in0_label.dev_attr.attr,
+	&sensor_dev_attr_in1_input.dev_attr.attr,
+	&sensor_dev_attr_in1_label.dev_attr.attr,
+	&sensor_dev_attr_in2_input.dev_attr.attr,
+	&sensor_dev_attr_in2_label.dev_attr.attr,
+	&sensor_dev_attr_in3_input.dev_attr.attr,
+	&sensor_dev_attr_in3_label.dev_attr.attr,
+
+	&sensor_dev_attr_temp1_input.dev_attr.attr,
+	&sensor_dev_attr_temp1_label.dev_attr.attr,
+	NULL
+};
+
+static const struct attribute_group da9055_attr_group = {.attrs = da9055_attr};
+
+static int da9055_hwmon_probe(struct platform_device *pdev)
+{
+	struct da9055_hwmon *hwmon;
+	int hwmon_irq, ret;
+
+	hwmon = devm_kzalloc(&pdev->dev, sizeof(struct da9055_hwmon),
+			     GFP_KERNEL);
+	if (!hwmon)
+		return -ENOMEM;
+
+	mutex_init(&hwmon->hwmon_lock);
+	mutex_init(&hwmon->irq_lock);
+
+	init_completion(&hwmon->done);
+	hwmon->da9055 = dev_get_drvdata(pdev->dev.parent);
+
+	platform_set_drvdata(pdev, hwmon);
+
+	hwmon_irq = platform_get_irq_byname(pdev, "HWMON");
+	if (hwmon_irq < 0)
+		return hwmon_irq;
+
+	hwmon_irq = regmap_irq_get_virq(hwmon->da9055->irq_data, hwmon_irq);
+	if (hwmon_irq < 0)
+		return hwmon_irq;
+
+	ret = devm_request_threaded_irq(&pdev->dev, hwmon_irq,
+					NULL, da9055_auxadc_irq,
+					IRQF_TRIGGER_HIGH | IRQF_ONESHOT,
+					"adc-irq", hwmon);
+	if (ret != 0) {
+		dev_err(hwmon->da9055->dev, "DA9055 ADC IRQ failed ret=%d\n",
+			ret);
+		return ret;
+	}
+
+	ret = sysfs_create_group(&pdev->dev.kobj, &da9055_attr_group);
+	if (ret)
+		return ret;
+
+	hwmon->class_device = hwmon_device_register(&pdev->dev);
+	if (IS_ERR(hwmon->class_device)) {
+		ret = PTR_ERR(hwmon->class_device);
+		goto err;
+	}
+
+	return 0;
+
+err:
+	sysfs_remove_group(&pdev->dev.kobj, &da9055_attr_group);
+	return ret;
+}
+
+static int da9055_hwmon_remove(struct platform_device *pdev)
+{
+	struct da9055_hwmon *hwmon = platform_get_drvdata(pdev);
+
+	sysfs_remove_group(&pdev->dev.kobj, &da9055_attr_group);
+	hwmon_device_unregister(hwmon->class_device);
+
+	return 0;
+}
+
+static struct platform_driver da9055_hwmon_driver = {
+	.probe = da9055_hwmon_probe,
+	.remove = da9055_hwmon_remove,
+	.driver = {
+		.name = "da9055-hwmon",
+		.owner = THIS_MODULE,
+	},
+};
+
+module_platform_driver(da9055_hwmon_driver);
+
+MODULE_AUTHOR("David Dajun Chen <dchen@diasemi.com>");
+MODULE_DESCRIPTION("DA9055 HWMON driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:da9055-hwmon");