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 <anantha.narayanan@intel.com>
[The 4K and 64K in the hw spec actually means 4095 (12bit) and 65535 (16bit).]
Signed-off-by: Hong Liu <hong.liu@intel.com>
[Updated to match the ALS light API interface convention from Samu]
Signed-off-by: Alan Cox <alan@linux.intel.com>
Acked-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 308 insertions, 0 deletions

diff --git a/drivers/misc/apds9802als.c b/drivers/misc/apds9802als.c
new file mode 100644
index 000000000000..fbe49602f396
--- /dev/null
+++ b/drivers/misc/apds9802als.c
@@ -0,0 +1,308 @@
+/*
+ * 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 <Anantha.Narayanan@intel.com");
+MODULE_DESCRIPTION("Avago apds9802als ALS Driver");
+MODULE_LICENSE("GPL v2");