| /* 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; |
| attr->dev_attr.attr.name = attrs->in_name; |
| attr->dev_attr.attr.mode = S_IRUGO; |
| attr->dev_attr.attr.owner = THIS_MODULE; |
| 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; |
| attr->dev_attr.attr.name = attrs->label_name; |
| attr->dev_attr.attr.mode = S_IRUGO; |
| attr->dev_attr.attr.owner = THIS_MODULE; |
| 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 = kzalloc(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"); |
| ret = PTR_ERR(hwmon->client); |
| goto err_mem; |
| } |
| |
| /* 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); |
| |
| err_mem: |
| kfree(hwmon); |
| 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), |
| }; |
| |
| static int __init s3c_hwmon_init(void) |
| { |
| return platform_driver_register(&s3c_hwmon_driver); |
| } |
| |
| static void __exit s3c_hwmon_exit(void) |
| { |
| platform_driver_unregister(&s3c_hwmon_driver); |
| } |
| |
| module_init(s3c_hwmon_init); |
| module_exit(s3c_hwmon_exit); |
| |
| MODULE_AUTHOR("Ben Dooks <ben@simtec.co.uk>"); |
| MODULE_DESCRIPTION("S3C ADC HWMon driver"); |
| MODULE_LICENSE("GPL v2"); |
| MODULE_ALIAS("platform:s3c-hwmon"); |