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

Guenter Roeck
2011-04-30T03:40:30Z

On Fri, Apr 29, 2011 at 06:21:52PM -0400, Vivien Didelot wrote:
> From: Jonas Fonseca <jonas.fonseca@savoirfairelinux.com>
>
>
> Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com>

Hi Vivien,

The headline and file name are a bit misleading, since the driver is really
for MAX197 on a TS-5500 board.

You should split the driver into two parts, a generic driver
for the MAX197 and a platform driver (residing somewhere in arch/
or possibly drivers/platform/) to instantiate it.

There should be a platform data include file, probably in
include/linux/platform_data/.

.ioaddr in platform data should not be necessary. The driver's probe
function should get the values using platform_get_resource().

Having said that, from reading the code it looks like the chip is not really
used for hardware monitoring, but for generic ADC functionality. A quick look
into the TS-5500 user manual confirms this. So this should not be a hwmon
driver in the first place, but a generic ADC driver. Given the ADC conversion rate
of the MAX197, the hwmon ABI is not optimal anyway. You should move this driver
into the iio subsystem, probably to drivers/staging/iio/adc. Copying the iio
mailing list for input.

Thanks,
Guenter

> ---
> 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
>
>
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