drivers/misc/apds9802als.c: ALS drivers for the apds9802als

This adds support for the ADPS9802ALS sensor.

Cleanup by Alan Cox
- move mutexes to cover more things
- report I/O errors back to user space
- report range and values in LUX

Signed-off-by: Anantha Narayanan <[e-mail]>
[The 4K and 64K in the hw spec actually means 4095 (12bit) and 65535 (16bit).]
Signed-off-by: Hong Liu <[e-mail]>
[Updated to match the ALS light API interface convention from Samu]
Signed-off-by: Alan Cox <[e-mail]>
Acked-by: Jonathan Cameron <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/misc/Kconfig

···
 	This option enables addition debugging code for the SGI GRU driver. If
 	you are unsure, say N.
 
+config APDS9802ALS
+	tristate "Medfield Avago APDS9802 ALS Sensor module"
+	depends on I2C
+	help
+	  If you say yes here you get support for the ALS APDS9802 ambient
+	  light sensor.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called apds9802als.
+
 config ISL29003
 	tristate "Intersil ISL29003 ambient light sensor"
 	depends on I2C && SYSFS

drivers/misc/Makefile

···
 obj-$(CONFIG_SGI_GRU)		+= sgi-gru/
 obj-$(CONFIG_CS5535_MFGPT)	+= cs5535-mfgpt.o
 obj-$(CONFIG_HP_ILO)		+= hpilo.o
+obj-$(CONFIG_APDS9802ALS)	+= apds9802als.o
 obj-$(CONFIG_ISL29003)		+= isl29003.o
 obj-$(CONFIG_ISL29020)		+= isl29020.o
 obj-$(CONFIG_SENSORS_TSL2550)	+= tsl2550.o

drivers/misc/apds9802als.c

···
+/*
+ * apds9802als.c - apds9802  ALS Driver
+ *
+ * Copyright (C) 2009 Intel Corp
+ *
+ *  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ *
+ * 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; version 2 of the License.
+ *
+ * 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/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/mutex.h>
+#include <linux/sysfs.h>
+#include <linux/hwmon-sysfs.h>
+
+#define ALS_MIN_RANGE_VAL 1
+#define ALS_MAX_RANGE_VAL 2
+#define POWER_STA_ENABLE 1
+#define POWER_STA_DISABLE 0
+#define APDS9802ALS_I2C_ADDR 0x29
+
+#define DRIVER_NAME "apds9802als"
+
+struct als_data {
+	struct device *hwmon_dev;
+	bool needresume;
+	struct mutex mutex;
+};
+
+static ssize_t als_sensing_range_show(struct device *dev,
+			struct device_attribute *attr,  char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	int  val;
+
+	val = i2c_smbus_read_byte_data(client, 0x81);
+	if (val < 0)
+		return val;
+	if (val & 1)
+		return sprintf(buf, "4095\n");
+	else
+		return sprintf(buf, "65535\n");
+}
+
+static ssize_t als_lux0_input_data_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct als_data *data = i2c_get_clientdata(client);
+	unsigned int ret_val;
+	int temp;
+
+	/* Protect against parallel reads */
+	mutex_lock(&data->mutex);
+	temp = i2c_smbus_read_byte_data(client, 0x8C);/*LSB data*/
+	if (temp < 0) {
+		ret_val = temp;
+		goto failed;
+	}
+	ret_val = i2c_smbus_read_byte_data(client, 0x8D);/*MSB data*/
+	if (ret_val < 0)
+		goto failed;
+	mutex_unlock(&data->mutex);
+	ret_val = (ret_val << 8) | temp;
+	return sprintf(buf, "%d\n", ret_val);
+failed:
+	mutex_unlock(&data->mutex);
+	return ret_val;
+}
+
+static ssize_t als_sensing_range_store(struct device *dev,
+		struct device_attribute *attr, const  char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct als_data *data = i2c_get_clientdata(client);
+	unsigned int ret_val;
+	unsigned long val;
+
+	if (strict_strtoul(buf, 10, &val))
+		return -EINVAL;
+
+	if (val < 4096)
+		val = 1;
+	else if (val < 65536)
+		val = 2;
+	else
+		return -ERANGE;
+
+	/* Make sure nobody else reads/modifies/writes 0x81 while we
+	   are active */
+
+	mutex_lock(&data->mutex);
+
+	ret_val = i2c_smbus_read_byte_data(client, 0x81);
+	if (ret_val < 0)
+		goto fail;
+
+	/* Reset the bits before setting them */
+	ret_val = ret_val & 0xFA;
+
+	if (val == 1) /* Setting the continous measurement up to 4k LUX */
+		ret_val = (ret_val | 0x05);
+	else /* Setting the continous measurement up to 64k LUX*/
+		ret_val = (ret_val | 0x04);
+
+	ret_val = i2c_smbus_write_byte_data(client, 0x81, ret_val);
+	if (ret_val >= 0) {
+		/* All OK */
+		mutex_unlock(&data->mutex);
+		return count;
+	}
+fail:
+	mutex_unlock(&data->mutex);
+	return ret_val;
+}
+
+static ssize_t als_power_status_show(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	int ret_val;
+	ret_val = i2c_smbus_read_byte_data(client, 0x80);
+	if (ret_val < 0)
+		return ret_val;
+	ret_val = ret_val & 0x01;
+	return sprintf(buf, "%d\n", ret_val);
+}
+
+static int als_set_power_state(struct i2c_client *client, bool on_off)
+{
+	int ret_val;
+	struct als_data *data = i2c_get_clientdata(client);
+
+	mutex_lock(&data->mutex);
+	ret_val = i2c_smbus_read_byte_data(client, 0x80);
+	if (ret_val < 0)
+		goto fail;
+	if (on_off)
+		ret_val = ret_val | 0x01;
+	else
+		ret_val = ret_val & 0xFE;
+	ret_val = i2c_smbus_write_byte_data(client, 0x80, ret_val);
+fail:
+	mutex_unlock(&data->mutex);
+	return ret_val;
+}
+
+static ssize_t als_power_status_store(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct als_data *data = i2c_get_clientdata(client);
+	unsigned long val;
+	int ret_val;
+
+	if (strict_strtoul(buf, 10, &val))
+		return -EINVAL;
+	if (val == POWER_STA_ENABLE) {
+		ret_val = als_set_power_state(client, true);
+		data->needresume = true;
+	} else if (val == POWER_STA_DISABLE) {
+		ret_val = als_set_power_state(client, false);
+		data->needresume = false;
+	} else
+		return -EINVAL;
+	if (ret_val < 0)
+		return ret_val;
+	return count;
+}
+
+static DEVICE_ATTR(lux0_sensor_range, S_IRUGO | S_IWUSR,
+	als_sensing_range_show, als_sensing_range_store);
+static DEVICE_ATTR(lux0_input, S_IRUGO, als_lux0_input_data_show, NULL);
+static DEVICE_ATTR(power_state, S_IRUGO | S_IWUSR,
+	als_power_status_show, als_power_status_store);
+
+static struct attribute *mid_att_als[] = {
+	&dev_attr_lux0_sensor_range.attr,
+	&dev_attr_lux0_input.attr,
+	&dev_attr_power_state.attr,
+	NULL
+};
+
+static struct attribute_group m_als_gr = {
+	.name = "apds9802als",
+	.attrs = mid_att_als
+};
+
+static int als_set_default_config(struct i2c_client *client)
+{
+	int ret_val;
+	/* Write the command and then switch on */
+	ret_val = i2c_smbus_write_byte_data(client, 0x80, 0x01);
+	if (ret_val < 0) {
+		dev_err(&client->dev, "failed default switch on write\n");
+		return ret_val;
+	}
+	/* Continous from 1Lux to 64k Lux */
+	ret_val = i2c_smbus_write_byte_data(client, 0x81, 0x04);
+	if (ret_val < 0)
+		dev_err(&client->dev, "failed default LUX on write\n");
+	return ret_val;
+}
+
+static int  apds9802als_probe(struct i2c_client *client,
+					const struct i2c_device_id *id)
+{
+	int res;
+	struct als_data *data;
+
+	data = kzalloc(sizeof(struct als_data), GFP_KERNEL);
+	if (data == NULL) {
+		dev_err(&client->dev, "Memory allocation failed\n");
+		return -ENOMEM;
+	}
+	i2c_set_clientdata(client, data);
+	res = sysfs_create_group(&client->dev.kobj, &m_als_gr);
+	if (res) {
+		dev_err(&client->dev, "device create file failed\n");
+		goto als_error1;
+	}
+	dev_info(&client->dev,
+		"%s apds9802als: ALS chip found\n", client->name);
+	als_set_default_config(client);
+	data->needresume = true;
+	mutex_init(&data->mutex);
+	return res;
+als_error1:
+	i2c_set_clientdata(client, NULL);
+	kfree(data);
+	return res;
+}
+
+static int apds9802als_remove(struct i2c_client *client)
+{
+	struct als_data *data = i2c_get_clientdata(client);
+	sysfs_remove_group(&client->dev.kobj, &m_als_gr);
+	kfree(data);
+	return 0;
+}
+
+static int apds9802als_suspend(struct i2c_client *client, pm_message_t mesg)
+{
+	als_set_power_state(client, false);
+	return 0;
+}
+
+static int apds9802als_resume(struct i2c_client *client)
+{
+	struct als_data *data = i2c_get_clientdata(client);
+
+	if (data->needresume == true)
+		als_set_power_state(client, true);
+	return 0;
+}
+
+static struct i2c_device_id apds9802als_id[] = {
+	{ DRIVER_NAME, 0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(i2c, apds9802als_id);
+
+static struct i2c_driver apds9802als_driver = {
+	.driver = {
+	.name = DRIVER_NAME,
+	.owner = THIS_MODULE,
+	},
+	.probe = apds9802als_probe,
+	.remove = apds9802als_remove,
+	.suspend = apds9802als_suspend,
+	.resume = apds9802als_resume,
+	.id_table = apds9802als_id,
+};
+
+static int __init sensor_apds9802als_init(void)
+{
+	return i2c_add_driver(&apds9802als_driver);
+}
+
+static void  __exit sensor_apds9802als_exit(void)
+{
+	i2c_del_driver(&apds9802als_driver);
+}
+module_init(sensor_apds9802als_init);
+module_exit(sensor_apds9802als_exit);
+
+MODULE_AUTHOR("Anantha Narayanan <[e-mail]");
+MODULE_DESCRIPTION("Avago apds9802als ALS Driver");
+MODULE_LICENSE("GPL v2");