/* linux/drivers/hwmon/s3c-hwmon.c * * Copyright (C) 2005, 2008, 2009 Simtec Electronics * http://armlinux.simtec.co.uk/ * Ben Dooks <ben@simtec.co.uk> * * S3C24XX/S3C64XX ADC hwmon support * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ #include <linux/module.h> #include <linux/slab.h> #include <linux/delay.h> #include <linux/io.h> #include <linux/init.h> #include <linux/err.h> #include <linux/clk.h> #include <linux/interrupt.h> #include <linux/platform_device.h> #include <linux/hwmon.h> #include <linux/hwmon-sysfs.h> #include <plat/adc.h> #include <plat/hwmon.h> struct s3c_hwmon_attr { struct sensor_device_attribute in; struct sensor_device_attribute label; char in_name[12]; char label_name[12]; }; /** * struct s3c_hwmon - ADC hwmon client information * @lock: Access lock to serialise the conversions. * @client: The client we registered with the S3C ADC core. * @hwmon_dev: The hwmon device we created. * @attr: The holders for the channel attributes. */ struct s3c_hwmon { struct mutex lock; struct s3c_adc_client *client; struct device *hwmon_dev; struct s3c_hwmon_attr attrs[8]; }; /** * s3c_hwmon_read_ch - read a value from a given adc channel. * @dev: The device. * @hwmon: Our state. * @channel: The channel we're reading from. * * Read a value from the @channel with the proper locking and sleep until * either the read completes or we timeout awaiting the ADC core to get * back to us. */ static int s3c_hwmon_read_ch(struct device *dev, struct s3c_hwmon *hwmon, int channel) { int ret; ret = mutex_lock_interruptible(&hwmon->lock); if (ret < 0) return ret; dev_dbg(dev, "reading channel %d\n", channel); ret = s3c_adc_read(hwmon->client, channel); mutex_unlock(&hwmon->lock); return ret; } #ifdef CONFIG_SENSORS_S3C_RAW /** * s3c_hwmon_show_raw - show a conversion from the raw channel number. * @dev: The device that the attribute belongs to. * @attr: The attribute being read. * @buf: The result buffer. * * This show deals with the raw attribute, registered for each possible * ADC channel. This does a conversion and returns the raw (un-scaled) * value returned from the hardware. */ static ssize_t s3c_hwmon_show_raw(struct device *dev, struct device_attribute *attr, char *buf) { struct s3c_hwmon *adc = platform_get_drvdata(to_platform_device(dev)); struct sensor_device_attribute *sa = to_sensor_dev_attr(attr); int ret; ret = s3c_hwmon_read_ch(dev, adc, sa->index); return (ret < 0) ? ret : snprintf(buf, PAGE_SIZE, "%d\n", ret); } #define DEF_ADC_ATTR(x) \ static SENSOR_DEVICE_ATTR(adc##x##_raw, S_IRUGO, s3c_hwmon_show_raw, NULL, x) DEF_ADC_ATTR(0); DEF_ADC_ATTR(1); DEF_ADC_ATTR(2); DEF_ADC_ATTR(3); DEF_ADC_ATTR(4); DEF_ADC_ATTR(5); DEF_ADC_ATTR(6); DEF_ADC_ATTR(7); static struct attribute *s3c_hwmon_attrs[9] = { &sensor_dev_attr_adc0_raw.dev_attr.attr, &sensor_dev_attr_adc1_raw.dev_attr.attr, &sensor_dev_attr_adc2_raw.dev_attr.attr, &sensor_dev_attr_adc3_raw.dev_attr.attr, &sensor_dev_attr_adc4_raw.dev_attr.attr, &sensor_dev_attr_adc5_raw.dev_attr.attr, &sensor_dev_attr_adc6_raw.dev_attr.attr, &sensor_dev_attr_adc7_raw.dev_attr.attr, NULL, }; static struct attribute_group s3c_hwmon_attrgroup = { .attrs = s3c_hwmon_attrs, }; static inline int s3c_hwmon_add_raw(struct device *dev) { return sysfs_create_group(&dev->kobj, &s3c_hwmon_attrgroup); } static inline void s3c_hwmon_remove_raw(struct device *dev) { sysfs_remove_group(&dev->kobj, &s3c_hwmon_attrgroup); } #else static inline int s3c_hwmon_add_raw(struct device *dev) { return 0; } static inline void s3c_hwmon_remove_raw(struct device *dev) { } #endif /* CONFIG_SENSORS_S3C_RAW */ /** * s3c_hwmon_ch_show - show value of a given channel * @dev: The device that the attribute belongs to. * @attr: The attribute being read. * @buf: The result buffer. * * Read a value from the ADC and scale it before returning it to the * caller. The scale factor is gained from the channel configuration * passed via the platform data when the device was registered. */ static ssize_t s3c_hwmon_ch_show(struct device *dev, struct device_attribute *attr, char *buf) { struct sensor_device_attribute *sen_attr = to_sensor_dev_attr(attr); struct s3c_hwmon *hwmon = platform_get_drvdata(to_platform_device(dev)); struct s3c_hwmon_pdata *pdata = dev->platform_data; struct s3c_hwmon_chcfg *cfg; int ret; cfg = pdata->in[sen_attr->index]; ret = s3c_hwmon_read_ch(dev, hwmon, sen_attr->index); if (ret < 0) return ret; ret *= cfg->mult; ret = DIV_ROUND_CLOSEST(ret, cfg->div); return snprintf(buf, PAGE_SIZE, "%d\n", ret); } /** * s3c_hwmon_label_show - show label name of the given channel. * @dev: The device that the attribute belongs to. * @attr: The attribute being read. * @buf: The result buffer. * * Return the label name of a given channel */ static ssize_t s3c_hwmon_label_show(struct device *dev, struct device_attribute *attr, char *buf) { struct sensor_device_attribute *sen_attr = to_sensor_dev_attr(attr); struct s3c_hwmon_pdata *pdata = dev->platform_data; struct s3c_hwmon_chcfg *cfg; cfg = pdata->in[sen_attr->index]; return snprintf(buf, PAGE_SIZE, "%s\n", cfg->name); } /** * s3c_hwmon_create_attr - create hwmon attribute for given channel. * @dev: The device to create the attribute on. * @cfg: The channel configuration passed from the platform data. * @channel: The ADC channel number to process. * * Create the scaled attribute for use with hwmon from the specified * platform data in @pdata. The sysfs entry is handled by the routine * s3c_hwmon_ch_show(). * * The attribute name is taken from the configuration data if present * otherwise the name is taken by concatenating in_ with the channel * number. */ static int s3c_hwmon_create_attr(struct device *dev, struct s3c_hwmon_chcfg *cfg, struct s3c_hwmon_attr *attrs, int channel) { struct sensor_device_attribute *attr; int ret; snprintf(attrs->in_name, sizeof(attrs->in_name), "in%d_input", channel); attr = &attrs->in; attr->index = channel; sysfs_attr_init(&attr->dev_attr.attr); attr->dev_attr.attr.name = attrs->in_name; attr->dev_attr.attr.mode = S_IRUGO; attr->dev_attr.show = s3c_hwmon_ch_show; ret = device_create_file(dev, &attr->dev_attr); if (ret < 0) { dev_err(dev, "failed to create input attribute\n"); return ret; } /* if this has a name, add a label */ if (cfg->name) { snprintf(attrs->label_name, sizeof(attrs->label_name), "in%d_label", channel); attr = &attrs->label; attr->index = channel; sysfs_attr_init(&attr->dev_attr.attr); attr->dev_attr.attr.name = attrs->label_name; attr->dev_attr.attr.mode = S_IRUGO; attr->dev_attr.show = s3c_hwmon_label_show; ret = device_create_file(dev, &attr->dev_attr); if (ret < 0) { device_remove_file(dev, &attrs->in.dev_attr); dev_err(dev, "failed to create label attribute\n"); } } return ret; } static void s3c_hwmon_remove_attr(struct device *dev, struct s3c_hwmon_attr *attrs) { device_remove_file(dev, &attrs->in.dev_attr); device_remove_file(dev, &attrs->label.dev_attr); } /** * s3c_hwmon_probe - device probe entry. * @dev: The device being probed. */ static int __devinit s3c_hwmon_probe(struct platform_device *dev) { struct s3c_hwmon_pdata *pdata = dev->dev.platform_data; struct s3c_hwmon *hwmon; int ret = 0; int i; if (!pdata) { dev_err(&dev->dev, "no platform data supplied\n"); return -EINVAL; } hwmon = devm_kzalloc(&dev->dev, sizeof(struct s3c_hwmon), GFP_KERNEL); if (hwmon == NULL) { dev_err(&dev->dev, "no memory\n"); return -ENOMEM; } platform_set_drvdata(dev, hwmon); mutex_init(&hwmon->lock); /* Register with the core ADC driver. */ hwmon->client = s3c_adc_register(dev, NULL, NULL, 0); if (IS_ERR(hwmon->client)) { dev_err(&dev->dev, "cannot register adc\n"); return PTR_ERR(hwmon->client); } /* add attributes for our adc devices. */ ret = s3c_hwmon_add_raw(&dev->dev); if (ret) goto err_registered; /* register with the hwmon core */ hwmon->hwmon_dev = hwmon_device_register(&dev->dev); if (IS_ERR(hwmon->hwmon_dev)) { dev_err(&dev->dev, "error registering with hwmon\n"); ret = PTR_ERR(hwmon->hwmon_dev); goto err_raw_attribute; } for (i = 0; i < ARRAY_SIZE(pdata->in); i++) { struct s3c_hwmon_chcfg *cfg = pdata->in[i]; if (!cfg) continue; if (cfg->mult >= 0x10000) dev_warn(&dev->dev, "channel %d multiplier too large\n", i); if (cfg->div == 0) { dev_err(&dev->dev, "channel %d divider zero\n", i); continue; } ret = s3c_hwmon_create_attr(&dev->dev, pdata->in[i], &hwmon->attrs[i], i); if (ret) { dev_err(&dev->dev, "error creating channel %d\n", i); for (i--; i >= 0; i--) s3c_hwmon_remove_attr(&dev->dev, &hwmon->attrs[i]); goto err_hwmon_register; } } return 0; err_hwmon_register: hwmon_device_unregister(hwmon->hwmon_dev); err_raw_attribute: s3c_hwmon_remove_raw(&dev->dev); err_registered: s3c_adc_release(hwmon->client); return ret; } static int __devexit s3c_hwmon_remove(struct platform_device *dev) { struct s3c_hwmon *hwmon = platform_get_drvdata(dev); int i; s3c_hwmon_remove_raw(&dev->dev); for (i = 0; i < ARRAY_SIZE(hwmon->attrs); i++) s3c_hwmon_remove_attr(&dev->dev, &hwmon->attrs[i]); hwmon_device_unregister(hwmon->hwmon_dev); s3c_adc_release(hwmon->client); return 0; } static struct platform_driver s3c_hwmon_driver = { .driver = { .name = "s3c-hwmon", .owner = THIS_MODULE, }, .probe = s3c_hwmon_probe, .remove = __devexit_p(s3c_hwmon_remove), }; module_platform_driver(s3c_hwmon_driver); MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); MODULE_DESCRIPTION("S3C ADC HWMon driver"); MODULE_LICENSE("GPL v2"); MODULE_ALIAS("platform:s3c-hwmon");