[RFC 5/5] hwmon: add support for Technologic Systems TS-5500 A-D converter

Vivien Didelot
2011-04-29T22:33:28Z

From: Jonas Fonseca <jonas.fonseca@savoirfairelinux.com>

Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>
---
MAINTAINERS | 1 +
drivers/hwmon/Kconfig | 10 +
drivers/hwmon/Makefile | 1 +
drivers/hwmon/ts5500-adc.c | 481 ++++++++++++++++++++++++++++++++++++++++++++
4 files changed, 493 insertions(+), 0 deletions(-)
create mode 100644 drivers/hwmon/ts5500-adc.c

diff --git a/MAINTAINERS b/MAINTAINERS
index c0a646d..aace74a 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6062,6 +6062,7 @@ F: drivers/gpio/ts5500-gpio.c
F: include/linux/ts5500-gpio.h
F: drivers/tty/serial/ts5500-auto485.c
F: drivers/leds/leds-ts5500.c
+F: drivers/hwmon/ts5500-adc.c

TEGRA SUPPORT
M: Colin Cross <ccross@android.com>
diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 060ef63..5070530 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1286,6 +1286,16 @@ config SENSORS_MC13783_ADC
help
Support for the A/D converter on MC13783 PMIC.

+config SENSORS_TS5500_ADC
+ tristate "Technologic Systems TS-5500 ADC"
+ depends on TS5500_SBC
+ help
+ Support for the A/D converter on Technologic Systems TS-5500
+ SBCs.
+
+ This driver can also be built as a module. If so, the module
+ will be called ts5500-adc.
+
if ACPI

comment "ACPI drivers"
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 967d0ea..9c8563d 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -114,6 +114,7 @@ obj-$(CONFIG_SENSORS_W83L785TS) += w83l785ts.o
obj-$(CONFIG_SENSORS_W83L786NG) += w83l786ng.o
obj-$(CONFIG_SENSORS_WM831X) += wm831x-hwmon.o
obj-$(CONFIG_SENSORS_WM8350) += wm8350-hwmon.o
+obj-$(CONFIG_SENSORS_TS5500_ADC)+= ts5500-adc.o

# PMBus drivers
obj-$(CONFIG_PMBUS) += pmbus_core.o
diff --git a/drivers/hwmon/ts5500-adc.c b/drivers/hwmon/ts5500-adc.c
new file mode 100644
index 0000000..6568e9e
--- /dev/null
+++ b/drivers/hwmon/ts5500-adc.c
@@ -0,0 +1,481 @@
+/*
+ * Technologic Systems TS-5500 boards - MAX197 ADC driver
+ *
+ * Copyright (c) 2010 Savoir-faire Linux Inc.
+ * Jonas Fonseca <jonas.fonseca@savoirfairelinux.com>
+ *
+ * Portions Copyright (C) 2008 Marc Pignat <marc.pignat@hevs.ch>
+ *
+ * The driver uses direct access for communication with the ADC.
+ * Should work unchanged with the MAX199 chip.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/delay.h>
+#include <linux/platform_device.h>
+#include <linux/err.h>
+#include <linux/sysfs.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/mutex.h>
+#include <linux/ts5xxx-sbcinfo.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#define MODULE_NAME "ts5500-max197"
+
+/*
+ * Control bits of A/D command
+ * bits 0-2: selected channel (0 - 7)
+ * bits 3: uni/bipolar (0 = unipolar (ie 0 to +5V))
+ * (1 = bipolar (ie -5 to +5V))
+ * bit 4: selected range (0 = 5v range, 1 = 10V range)
+ * bit 5-7: padded zero (unused)
+ */
+#define TS5500_MAX197_BIPOLAR 0x08
+#define TS5500_MAX197_UNIPOLAR 0x00
+#define TS5500_MAX197_RANGE_5V 0x00 /* 0 to 5V range */
+#define TS5500_MAX197_RANGE_10V 0x10 /* 0 to 10V range */
+
+#define TS5500_MAX197_READ_DELAY 15 /* usec */
+#define TS5500_MAX197_READ_BUSY_MASK 0x01
+#define TS5500_MAX197_NAME "MAX197 (8 channels)"
+
+#define MAX197_CHANNELS_MAX 8 /* 0 to 7 channels on device */
+
+#define max197_test_bit(bit, map) (test_bit(bit, map) != 0)
+
+/**
+ * struct max197_platform_data
+ * @name: Name of the device.
+ * @ioaddr: I/O address containing:
+ * .data: Data register for conversion reading.
+ * .ctrl: A/D Control Register (bit 0 = 0 when
+ * conversion completed).
+ * @read: Information about conversion reading, with:
+ * .delay: Delay before next conversion.
+ * .busy_mask: Control register bit 0 equals 1 means
+ * conversion is not completed yet.
+ * @ctrl: Data tables addressable by [polarity][range].
+ * @ranges: Ranges.
+ * .min: Min value.
+ * .max: Max value.
+ * @scale: Polarity/Range coefficients to scale raw conversion reading.
+ */
+struct max197_platform_data {
+ const char *name;
+ struct {
+ int data;
+ int ctrl;
+ } ioaddr;
+ struct {
+ u8 delay;
+ u8 busy_mask;
+ } read;
+ u8 ctrl[2][2];
+ struct {
+ int min[2][2];
+ int max[2][2];
+ } ranges;
+ int scale[2][2];
+};
+
+/**
+ * struct max197_chip
+ * @hwmon_dev: The hwmon device.
+ * @lock: Read/Write mutex.
+ * @spec: The MAX197 platform data.
+ * @polarity: bitmap for polarity.
+ * @range: bitmap for range.
+ */
+struct max197_chip {
+ struct device *hwmon_dev;
+ struct mutex lock;
+ struct max197_platform_data spec;
+ DECLARE_BITMAP(polarity, MAX197_CHANNELS_MAX);
+ DECLARE_BITMAP(range, MAX197_CHANNELS_MAX);
+};
+
+static inline s32 max197_scale(struct max197_chip *chip, s16 raw,
+ int polarity, int range)
+{
+ s32 scaled = raw;
+
+ scaled *= chip->spec.scale[polarity][range];
+ scaled /= 10000;
+
+ return scaled;
+}
+
+static inline int max197_range(struct max197_chip *chip, int is_min,
+ int polarity, int range)
+{
+ if (is_min)
+ return chip->spec.ranges.min[polarity][range];
+ return chip->spec.ranges.max[polarity][range];
+}
+
+static inline int max197_strtol(const char *buf, long *value, int range1,
+ int range2)
+{
+ if (strict_strtol(buf, 10, value))
+ return -EINVAL;
+
+ if (range1 < range2)
+ *value = SENSORS_LIMIT(*value, range1, range2);
+ else
+ *value = SENSORS_LIMIT(*value, range2, range1);
+
+ return 0;
+}
+
+static inline struct max197_chip *max197_get_drvdata(struct device *dev)
+{
+ return platform_get_drvdata(to_platform_device(dev));
+}
+
+/**
+ * max197_show_range() - Display range on user output
+ *
+ * Function called on read access on
+ * /sys/devices/platform/ts5500-max197/in{0,1,2,3,4,5,6,7}_{min,max}
+ */
+static ssize_t max197_show_range(struct device *dev,
+ struct device_attribute *devattr, char *buf)
+{
+ struct max197_chip *chip = max197_get_drvdata(dev);
+ struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
+ int is_min = attr->nr != 0;
+ int polarity, range;
+
+ if (mutex_lock_interruptible(&chip->lock))
+ return -ERESTARTSYS;
+
+ polarity = max197_test_bit(attr->index, chip->polarity);
+ range = max197_test_bit(attr->index, chip->range);
+
+ mutex_unlock(&chip->lock);
+
+ return sprintf(buf, "%d\n",
+ max197_range(chip, is_min, polarity, range));
+}
+
+/**
+ * max197_store_range() - Write range from user input
+ *
+ * Function called on write access on
+ * /sys/devices/platform/ts5500-max197/in{0,1,2,3,4,5,6,7}_{min,max}
+ */
+static ssize_t max197_store_range(struct device *dev,
+ struct device_attribute *devattr,
+ const char *buf, size_t count)
+{
+ struct max197_chip *chip = max197_get_drvdata(dev);
+ struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr);
+ int is_min = attr->nr != 0;
+ int range1 = max197_range(chip, is_min, 0, 0);
+ int range2 = max197_range(chip, is_min, 1, 1);
+ long value;
+
+ if (max197_strtol(buf, &value, range1, range2))
+ return -EINVAL;
+
+ if (mutex_lock_interruptible(&chip->lock))
+ return -ERESTARTSYS;
+
+ if (abs(value) > 5000)
+ set_bit(attr->index, chip->range);
+ else
+ clear_bit(attr->index, chip->range);
+
+ if (is_min) {
+ if (value < 0)
+ set_bit(attr->index, chip->polarity);
+ else
+ clear_bit(attr->index, chip->polarity);
+ }
+
+ mutex_unlock(&chip->lock);
+
+ return count;
+}
+
+/**
+ * max197_show_input() - Show channel input
+ *
+ * Function called on read access on
+ * /sys/devices/platform/ts5500-max197/in{0,1,2,3,4,5,6,7}_input
+ */
+static ssize_t max197_show_input(struct device *dev,
+ struct device_attribute *devattr, char *buf)
+{
+ struct max197_chip *chip = max197_get_drvdata(dev);
+ struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr);
+ int polarity, range;
+ int ret;
+ u8 command;
+
+ if (mutex_lock_interruptible(&chip->lock))
+ return -ERESTARTSYS;
+
+ polarity = max197_test_bit(attr->index, chip->polarity);
+ range = max197_test_bit(attr->index, chip->range);
+
+ command = attr->index | chip->spec.ctrl[polarity][range];
+
+ outb(command, chip->spec.ioaddr.data);
+
+ udelay(chip->spec.read.delay);
+ ret = inb(chip->spec.ioaddr.ctrl);
+
+ if (ret & chip->spec.read.busy_mask) {
+ dev_err(dev, "device not ready (ret=0x0%x, try=%d)\n", ret,
+ range);
+ ret = -EIO;
+ } else {
+ /* LSB of conversion is at 0x196 and MSB is at 0x197 */
+ u8 lsb = inb(chip->spec.ioaddr.data);
+ u8 msb = inb(chip->spec.ioaddr.data + 1);
+ s16 raw = (msb << 8) | lsb;
+ s32 scaled = max197_scale(chip, raw, polarity, range);
+
+ ret = sprintf(buf, "%d\n", scaled);
+ }
+
+ mutex_unlock(&chip->lock);
+ return ret;
+}
+
+static ssize_t max197_show_name(struct device *dev,
+ struct device_attribute *devattr, char *buf)
+{
+ return sprintf(buf, "%s\n", max197_get_drvdata(dev)->spec.name);
+}
+
+#define MAX197_HWMON_CHANNEL(chan) \
+ SENSOR_DEVICE_ATTR(in##chan##_input, S_IRUGO, \
+ max197_show_input, NULL, chan); \
+ SENSOR_DEVICE_ATTR_2(in##chan##_max, S_IRUGO | S_IWUSR, \
+ max197_show_range, \
+ max197_store_range, 0, chan); \
+ SENSOR_DEVICE_ATTR_2(in##chan##_min, S_IRUGO | S_IWUSR, \
+ max197_show_range, \
+ max197_store_range, 1, chan) \
+
+#define MAX197_SYSFS_CHANNEL(chan) \
+ &sensor_dev_attr_in##chan##_input.dev_attr.attr, \
+ &sensor_dev_attr_in##chan##_max.dev_attr.attr, \
+ &sensor_dev_attr_in##chan##_min.dev_attr.attr
+
+static DEVICE_ATTR(name, S_IRUGO, max197_show_name, NULL);
+
+static MAX197_HWMON_CHANNEL(0);
+static MAX197_HWMON_CHANNEL(1);
+static MAX197_HWMON_CHANNEL(2);
+static MAX197_HWMON_CHANNEL(3);
+static MAX197_HWMON_CHANNEL(4);
+static MAX197_HWMON_CHANNEL(5);
+static MAX197_HWMON_CHANNEL(6);
+static MAX197_HWMON_CHANNEL(7);
+
+static const struct attribute_group max197_sysfs_group = {
+ .attrs = (struct attribute *[]) {
+ &dev_attr_name.attr,
+ MAX197_SYSFS_CHANNEL(0),
+ MAX197_SYSFS_CHANNEL(1),
+ MAX197_SYSFS_CHANNEL(2),
+ MAX197_SYSFS_CHANNEL(3),
+ MAX197_SYSFS_CHANNEL(4),
+ MAX197_SYSFS_CHANNEL(5),
+ MAX197_SYSFS_CHANNEL(6),
+ MAX197_SYSFS_CHANNEL(7),
+ NULL
+ }
+};
+
+static int __devinit max197_probe(struct platform_device *pdev)
+{
+ struct max197_platform_data *pdata = pdev->dev.platform_data;
+ struct max197_chip *chip;
+ int ret;
+
+ if (pdata == NULL)
+ return -ENODEV;
+
+ chip = kzalloc(sizeof *chip, GFP_KERNEL);
+ if (!chip)
+ return -ENOMEM;
+
+ chip->spec = *pdata;
+
+ mutex_init(&chip->lock);
+ mutex_lock(&chip->lock);
+
+ ret = sysfs_create_group(&pdev->dev.kobj, &max197_sysfs_group);
+ if (ret) {
+ dev_err(&pdev->dev, "sysfs_create_group failed.\n");
+ goto error_unlock_and_free;
+ }
+
+ chip->hwmon_dev = hwmon_device_register(&pdev->dev);
+ if (IS_ERR(chip->hwmon_dev)) {
+ dev_err(&pdev->dev, "hwmon_device_register failed.\n");
+ ret = PTR_ERR(chip->hwmon_dev);
+ goto error_unregister_device;
+ }
+
+ platform_set_drvdata(pdev, chip);
+ mutex_unlock(&chip->lock);
+ return 0;
+
+error_unregister_device:
+ sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group);
+
+error_unlock_and_free:
+ mutex_unlock(&chip->lock);
+ kfree(chip);
+ return ret;
+}
+
+static int __devexit max197_remove(struct platform_device *pdev)
+{
+ struct max197_chip *chip = platform_get_drvdata(pdev);
+
+ mutex_lock(&chip->lock);
+ hwmon_device_unregister(chip->hwmon_dev);
+ sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group);
+ platform_set_drvdata(pdev, NULL);
+ mutex_unlock(&chip->lock);
+ kfree(chip);
+
+ return 0;
+}
+
+static struct platform_driver max197_driver = {
+ .driver = {
+ .name = MODULE_NAME,
+ .owner = THIS_MODULE,
+ },
+ .probe = max197_probe,
+ .remove = __devexit_p(max197_remove),
+};
+
+static void ts5500_max197_release(struct device *dev)
+{
+ /* noop */
+}
+
+static struct resource ts5500_max197_resources[] = {
+ {
+ .name = MODULE_NAME "-data",
+ .start = 0x196,
+ .end = 0x197,
+ .flags = IORESOURCE_IO,
+ },
+ {
+ .name = MODULE_NAME "-ctrl",
+ .start = 0x195,
+ .end = 0x195,
+ .flags = IORESOURCE_IO,
+ }
+};
+
+static struct max197_platform_data ts5500_max197_platform_data = {
+ .name = TS5500_MAX197_NAME,
+ .ioaddr = {
+ .data = 0x196,
+ .ctrl = 0x195,
+ },
+ .read = {
+ .delay = TS5500_MAX197_READ_DELAY,
+ .busy_mask = TS5500_MAX197_READ_BUSY_MASK,
+ },
+ .ctrl = {
+ { TS5500_MAX197_UNIPOLAR | TS5500_MAX197_RANGE_5V,
+ TS5500_MAX197_UNIPOLAR | TS5500_MAX197_RANGE_10V },
+ { TS5500_MAX197_BIPOLAR | TS5500_MAX197_RANGE_5V,
+ TS5500_MAX197_BIPOLAR | TS5500_MAX197_RANGE_10V },
+ },
+ .ranges = {
+ .min = {
+ { 0, 0 },
+ { -5000, -10000 },
+ },
+ .max = {
+ { 5000, 10000 },
+ { 5000, 10000 },
+ },
+ },
+ .scale = {
+ { 12207, 24414 },
+ { 24414, 48828 },
+ },
+};
+
+static struct platform_device ts5500_max197_device = {
+ .name = MODULE_NAME,
+ .id = -1,
+ .resource = ts5500_max197_resources,
+ .num_resources = ARRAY_SIZE(ts5500_max197_resources),
+ .dev = {
+ .platform_data = &ts5500_max197_platform_data,
+ .release = ts5500_max197_release,
+ },
+};
+
+static int __init ts5500_max197_init(void)
+{
+ struct ts5xxx_sbcinfo sbcinfo;
+ int ret;
+
+ ts5xxx_sbcinfo_set(&sbcinfo);
+ if (5500 != sbcinfo.board_id && !sbcinfo.adc) {
+ printk(MODULE_NAME ": Incompatible TS Board.\n");
+ return -ENODEV;
+ }
+
+ ret = platform_driver_register(&max197_driver);
+ if (ret)
+ goto error_out;
+
+ ret = platform_device_register(&ts5500_max197_device);
+ if (ret)
+ goto error_device_register;
+
+ return 0;
+
+error_device_register:
+ platform_driver_unregister(&max197_driver);
+error_out:
+ return ret;
+}
+module_init(ts5500_max197_init);
+
+static void __exit ts5500_max197_exit(void)
+{
+ platform_device_unregister(&ts5500_max197_device);
+ platform_driver_unregister(&max197_driver);
+}
+module_exit(ts5500_max197_exit);
+
+MODULE_DESCRIPTION("TS5500 MAX197 ADC device driver");
+MODULE_AUTHOR("Jonas Fonseca <jonas.fonseca@savoirfairelinux.com>");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:ts5500-max197");
--
1.7.1