diff options
Diffstat (limited to 'drivers/hwmon/mc13783-adc.c')
| -rw-r--r-- | drivers/hwmon/mc13783-adc.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/drivers/hwmon/mc13783-adc.c b/drivers/hwmon/mc13783-adc.c new file mode 100644 index 00000000000..883fa8197da --- /dev/null +++ b/drivers/hwmon/mc13783-adc.c @@ -0,0 +1,236 @@ +/* + * Driver for the Freescale Semiconductor MC13783 adc. + * + * Copyright 2004-2007 Freescale Semiconductor, Inc. All Rights Reserved. + * Copyright (C) 2009 Sascha Hauer, Pengutronix + * + * 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., 51 + * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include <linux/mfd/mc13783-private.h> +#include <linux/platform_device.h> +#include <linux/hwmon-sysfs.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/hwmon.h> +#include <linux/init.h> +#include <linux/err.h> + +#define MC13783_ADC_NAME "mc13783-adc" + +struct mc13783_adc_priv { + struct mc13783 *mc13783; + struct device *hwmon_dev; +}; + +static ssize_t mc13783_adc_show_name(struct device *dev, struct device_attribute + *devattr, char *buf) +{ + return sprintf(buf, "mc13783_adc\n"); +} + +static int mc13783_adc_read(struct device *dev, + struct device_attribute *devattr, unsigned int *val) +{ + struct platform_device *pdev = to_platform_device(dev); + struct mc13783_adc_priv *priv = platform_get_drvdata(pdev); + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); + unsigned int channel = attr->index; + unsigned int sample[4]; + int ret; + + ret = mc13783_adc_do_conversion(priv->mc13783, + MC13783_ADC_MODE_MULT_CHAN, + channel, sample); + if (ret) + return ret; + + channel &= 0x7; + + *val = (sample[channel % 4] >> (channel > 3 ? 14 : 2)) & 0x3ff; + + return 0; +} + +static ssize_t mc13783_adc_read_bp(struct device *dev, + struct device_attribute *devattr, char *buf) +{ + unsigned val; + int ret = mc13783_adc_read(dev, devattr, &val); + + if (ret) + return ret; + + /* + * BP (channel 2) reports with offset 2.4V to the actual value to fit + * the input range of the ADC. unit = 2.25mV = 9/4 mV. + */ + val = DIV_ROUND_CLOSEST(val * 9, 4) + 2400; + + return sprintf(buf, "%u\n", val); +} + +static ssize_t mc13783_adc_read_gp(struct device *dev, + struct device_attribute *devattr, char *buf) +{ + unsigned val; + int ret = mc13783_adc_read(dev, devattr, &val); + + if (ret) + return ret; + + /* + * input range is [0, 2.3V], val has 10 bits, so each bit + * is worth 9/4 mV. + */ + val = DIV_ROUND_CLOSEST(val * 9, 4); + + return sprintf(buf, "%u\n", val); +} + +static DEVICE_ATTR(name, S_IRUGO, mc13783_adc_show_name, NULL); +static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, mc13783_adc_read_bp, NULL, 2); +static SENSOR_DEVICE_ATTR(in5_input, S_IRUGO, mc13783_adc_read_gp, NULL, 5); +static SENSOR_DEVICE_ATTR(in6_input, S_IRUGO, mc13783_adc_read_gp, NULL, 6); +static SENSOR_DEVICE_ATTR(in7_input, S_IRUGO, mc13783_adc_read_gp, NULL, 7); +static SENSOR_DEVICE_ATTR(in8_input, S_IRUGO, mc13783_adc_read_gp, NULL, 8); +static SENSOR_DEVICE_ATTR(in9_input, S_IRUGO, mc13783_adc_read_gp, NULL, 9); +static SENSOR_DEVICE_ATTR(in10_input, S_IRUGO, mc13783_adc_read_gp, NULL, 10); +static SENSOR_DEVICE_ATTR(in11_input, S_IRUGO, mc13783_adc_read_gp, NULL, 11); +static SENSOR_DEVICE_ATTR(in12_input, S_IRUGO, mc13783_adc_read_gp, NULL, 12); +static SENSOR_DEVICE_ATTR(in13_input, S_IRUGO, mc13783_adc_read_gp, NULL, 13); +static SENSOR_DEVICE_ATTR(in14_input, S_IRUGO, mc13783_adc_read_gp, NULL, 14); +static SENSOR_DEVICE_ATTR(in15_input, S_IRUGO, mc13783_adc_read_gp, NULL, 15); + +static struct attribute *mc13783_attr[] = { + &dev_attr_name.attr, + &sensor_dev_attr_in2_input.dev_attr.attr, + &sensor_dev_attr_in5_input.dev_attr.attr, + &sensor_dev_attr_in6_input.dev_attr.attr, + &sensor_dev_attr_in7_input.dev_attr.attr, + &sensor_dev_attr_in8_input.dev_attr.attr, + &sensor_dev_attr_in9_input.dev_attr.attr, + &sensor_dev_attr_in10_input.dev_attr.attr, + &sensor_dev_attr_in11_input.dev_attr.attr, + NULL +}; + +static const struct attribute_group mc13783_group = { + .attrs = mc13783_attr, +}; + +/* last four channels may be occupied by the touchscreen */ +static struct attribute *mc13783_attr_ts[] = { + &sensor_dev_attr_in12_input.dev_attr.attr, + &sensor_dev_attr_in13_input.dev_attr.attr, + &sensor_dev_attr_in14_input.dev_attr.attr, + &sensor_dev_attr_in15_input.dev_attr.attr, + NULL +}; + +static const struct attribute_group mc13783_group_ts = { + .attrs = mc13783_attr_ts, +}; + +static int __init mc13783_adc_probe(struct platform_device *pdev) +{ + struct mc13783_adc_priv *priv; + int ret; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->mc13783 = dev_get_drvdata(pdev->dev.parent); + + platform_set_drvdata(pdev, priv); + + /* Register sysfs hooks */ + ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group); + if (ret) + goto out_err_create1; + + if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN)) + ret = sysfs_create_group(&pdev->dev.kobj, &mc13783_group_ts); + if (ret) + goto out_err_create2; + + priv->hwmon_dev = hwmon_device_register(&pdev->dev); + if (IS_ERR(priv->hwmon_dev)) { + ret = PTR_ERR(priv->hwmon_dev); + dev_err(&pdev->dev, + "hwmon_device_register failed with %d.\n", ret); + goto out_err_register; + } + + + return 0; + +out_err_register: + + if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN)) + sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts); +out_err_create2: + + sysfs_remove_group(&pdev->dev.kobj, &mc13783_group); +out_err_create1: + + platform_set_drvdata(pdev, NULL); + kfree(priv); + + return ret; +} + +static int __devexit mc13783_adc_remove(struct platform_device *pdev) +{ + struct mc13783_adc_priv *priv = platform_get_drvdata(pdev); + + hwmon_device_unregister(priv->hwmon_dev); + + if (!(priv->mc13783->flags & MC13783_USE_TOUCHSCREEN)) + sysfs_remove_group(&pdev->dev.kobj, &mc13783_group_ts); + + sysfs_remove_group(&pdev->dev.kobj, &mc13783_group); + + platform_set_drvdata(pdev, NULL); + kfree(priv); + + return 0; +} + +static struct platform_driver mc13783_adc_driver = { + .remove = __devexit_p(mc13783_adc_remove), + .driver = { + .owner = THIS_MODULE, + .name = MC13783_ADC_NAME, + }, +}; + +static int __init mc13783_adc_init(void) +{ + return platform_driver_probe(&mc13783_adc_driver, mc13783_adc_probe); +} + +static void __exit mc13783_adc_exit(void) +{ + platform_driver_unregister(&mc13783_adc_driver); +} + +module_init(mc13783_adc_init); +module_exit(mc13783_adc_exit); + +MODULE_DESCRIPTION("MC13783 ADC driver"); +MODULE_AUTHOR("Luotao Fu <l.fu@pengutronix.de>"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:" MC13783_ADC_NAME); |