Message-ID: <4AD9F750.9090800@cam.ac.uk>
Date:	Sat, 17 Oct 2009 17:56:48 +0100
From:	Jonathan Cameron <jic23@....ac.uk>
To:	LKML <linux-kernel@...r.kernel.org>,
	Zhang Rui <rui.zhang@...el.com>,
	Jean Delvare <khali@...ux-fr.org>,
	Rodolfo Giometti <giometti@...eenne.com>,
	"Michele De Candia (VT)" <michele.decandia@...ueteam.com>,
	Linux I2C <linux-i2c@...r.kernel.org>
Subject: [PATCH V2] ALS: TSL2550 driver move from i2c/chips

Signed-off-by: Jonathan Cameron <jic23@....ac.uk>

---
This is not a finished patch.  We still need to resolve
the debate on naming conventions with ALS. Basically
is there are a pressing reason for not having
/sys/class/als/als0/ etc and moving management into
the core?  Otherwise we end up with every driver having
to implement their own management systems and a lot
of code replication.

This will however work with current ALS patch set.

Additions since previous V1:
Removed set operating mode sysfs and replaced with
an illuminance0_range_max. If requested max is in
low range it will go with that, otherwise maximum
range is selected.

For now I've left the device id code etc alone,
as moving this into the ALS core is still under debate.

Couple of trivial style fixes thrown up by checkpatch
in the original driver that we might was well fix during
this move.

V1:

Minimal changes made. Untested due to lack of hardware.

Full patch this time rather than move one.

 Documentation/ABI/testing/sysfs-class-als |    9 +
 drivers/als/Kconfig                       |   14 +
 drivers/als/Makefile                      |    2 +
 drivers/als/tsl2550.c                     |  535 +++++++++++++++++++++++++++++
 drivers/i2c/chips/Kconfig                 |   10 -
 drivers/i2c/chips/Makefile                |    1 -
 drivers/i2c/chips/tsl2550.c               |  470 -------------------------
 7 files changed, 560 insertions(+), 481 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-class-als b/Documentation/ABI/testing/sysfs-class-als
index d3b33f3..9db1936 100644
--- a/Documentation/ABI/testing/sysfs-class-als
+++ b/Documentation/ABI/testing/sysfs-class-als
@@ -7,3 +7,12 @@ Description:	Current Ambient Light Illuminance reported by
 		Unit: lux (lumens per square meter)
 		RO
 
+What:		/sys/class/als/.../illuminance[n]_range_max
+Date:		Oct. 2009
+KernelVersion:	2.6.32
+Contact:	Jonathan Cameron <jic23@....ac.uk>
+Description:	Maximum value of Ambient Light Illuminance as
+		reported by ALS driver. Used when a device
+		has a multiple operating ranges.
+		Unit: lux (lumens per square meter)
+		RW
diff --git a/drivers/als/Kconfig b/drivers/als/Kconfig
index 200c52b..1564ffc 100644
--- a/drivers/als/Kconfig
+++ b/drivers/als/Kconfig
@@ -8,3 +8,17 @@ menuconfig ALS
 	  This framework provides a generic sysfs I/F for Ambient Light
 	  Sensor devices.
 	  If you want this support, you should say Y or M here.
+
+if ALS
+
+config ALS_TSL2550
+	tristate "Taos TSL2550 ambient light sensor"
+	depends on EXPERIMENTAL && I2C
+	help
+	  If you say yes here you get support for the Taos TSL2550
+	  ambient light sensor.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called tsl2550.
+
+endif #ALS
diff --git a/drivers/als/Makefile b/drivers/als/Makefile
index a527197..7be5631 100644
--- a/drivers/als/Makefile
+++ b/drivers/als/Makefile
@@ -3,3 +3,5 @@
 #
 
 obj-$(CONFIG_ALS)		+= als_sys.o
+
+obj-$(CONFIG_ALS_TSL2550)	+= tsl2550.o
\ No newline at end of file
diff --git a/drivers/als/tsl2550.c b/drivers/als/tsl2550.c
new file mode 100644
index 0000000..b75c1a9
--- /dev/null
+++ b/drivers/als/tsl2550.c
@@ -0,0 +1,535 @@
+/*
+ *  tsl2550.c - Linux kernel modules for ambient light sensor
+ *
+ *  Copyright (C) 2007 Rodolfo Giometti <giometti@...ux.it>
+ *  Copyright (C) 2007 Eurotech S.p.A. <info@...otech.it>
+ *
+ *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/mutex.h>
+#include <linux/err.h>
+#include <linux/idr.h>
+#include <linux/als_sys.h>
+
+#define TSL2550_DRV_NAME	"tsl2550"
+#define DRIVER_VERSION		"2.0"
+
+/*
+ * Defines
+ */
+
+#define TSL2550_POWER_DOWN		0x00
+#define TSL2550_POWER_UP		0x03
+#define TSL2550_STANDARD_RANGE		0x18
+#define TSL2550_EXTENDED_RANGE		0x1d
+#define TSL2550_READ_ADC0		0x43
+#define TSL2550_READ_ADC1		0x83
+
+/*
+ * Structs
+ */
+
+struct tsl2550_data {
+	struct device *classdev;
+	struct i2c_client *client;
+	struct mutex update_lock;
+	int id;
+
+	unsigned int power_state:1;
+	unsigned int operating_mode:1;
+};
+
+/*
+ * Global data
+ */
+
+static const u8 TSL2550_MODE_RANGE[2] = {
+	TSL2550_STANDARD_RANGE, TSL2550_EXTENDED_RANGE,
+};
+
+/*
+ * IDR to assign each registered device a unique id
+ */
+static DEFINE_IDR(tsl2550_idr);
+static DEFINE_SPINLOCK(tsl2550_idr_lock);
+#define TSL2550_DEV_MAX 9
+
+/*
+ * Management functions
+ */
+
+static int tsl2550_get_id(void)
+{
+	int ret, val;
+
+idr_again:
+	if (unlikely(idr_pre_get(&tsl2550_idr, GFP_KERNEL) == 0))
+		return -ENOMEM;
+	spin_lock(&tsl2550_idr_lock);
+	ret = idr_get_new(&tsl2550_idr, NULL, &val);
+	if (unlikely(ret == -EAGAIN))
+		goto idr_again;
+	else if (unlikely(ret))
+		return ret;
+	if (val > TSL2550_DEV_MAX)
+		return -ENOMEM;
+	return val;
+}
+
+static void tsl2550_free_id(int val)
+{
+	spin_lock(&tsl2550_idr_lock);
+	idr_remove(&tsl2550_idr, val);
+	spin_unlock(&tsl2550_idr_lock);
+}
+
+static int tsl2550_set_operating_mode(struct i2c_client *client, int mode)
+{
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+
+	int ret = i2c_smbus_write_byte(client, TSL2550_MODE_RANGE[mode]);
+
+	data->operating_mode = mode;
+
+	return ret;
+}
+
+static int tsl2550_set_power_state(struct i2c_client *client, int state)
+{
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+	int ret;
+
+	if (state == 0)
+		ret = i2c_smbus_write_byte(client, TSL2550_POWER_DOWN);
+	else {
+		ret = i2c_smbus_write_byte(client, TSL2550_POWER_UP);
+
+		/* On power up we should reset operating mode also... */
+		tsl2550_set_operating_mode(client, data->operating_mode);
+	}
+
+	data->power_state = state;
+
+	return ret;
+}
+
+static int tsl2550_get_adc_value(struct i2c_client *client, u8 cmd)
+{
+	int ret;
+
+	ret = i2c_smbus_read_byte_data(client, cmd);
+	if (ret < 0)
+		return ret;
+	if (!(ret & 0x80))
+		return -EAGAIN;
+	return ret & 0x7f;	/* remove the "valid" bit */
+}
+
+/*
+ * LUX calculation
+ */
+
+#define	TSL2550_MAX_LUX		1846
+
+static const u8 ratio_lut[] = {
+	100, 100, 100, 100, 100, 100, 100, 100,
+	100, 100, 100, 100, 100, 100, 99, 99,
+	99, 99, 99, 99, 99, 99, 99, 99,
+	99, 99, 99, 98, 98, 98, 98, 98,
+	98, 98, 97, 97, 97, 97, 97, 96,
+	96, 96, 96, 95, 95, 95, 94, 94,
+	93, 93, 93, 92, 92, 91, 91, 90,
+	89, 89, 88, 87, 87, 86, 85, 84,
+	83, 82, 81, 80, 79, 78, 77, 75,
+	74, 73, 71, 69, 68, 66, 64, 62,
+	60, 58, 56, 54, 52, 49, 47, 44,
+	42, 41, 40, 40, 39, 39, 38, 38,
+	37, 37, 37, 36, 36, 36, 35, 35,
+	35, 35, 34, 34, 34, 34, 33, 33,
+	33, 33, 32, 32, 32, 32, 32, 31,
+	31, 31, 31, 31, 30, 30, 30, 30,
+	30,
+};
+
+static const u16 count_lut[] = {
+	0, 1, 2, 3, 4, 5, 6, 7,
+	8, 9, 10, 11, 12, 13, 14, 15,
+	16, 18, 20, 22, 24, 26, 28, 30,
+	32, 34, 36, 38, 40, 42, 44, 46,
+	49, 53, 57, 61, 65, 69, 73, 77,
+	81, 85, 89, 93, 97, 101, 105, 109,
+	115, 123, 131, 139, 147, 155, 163, 171,
+	179, 187, 195, 203, 211, 219, 227, 235,
+	247, 263, 279, 295, 311, 327, 343, 359,
+	375, 391, 407, 423, 439, 455, 471, 487,
+	511, 543, 575, 607, 639, 671, 703, 735,
+	767, 799, 831, 863, 895, 927, 959, 991,
+	1039, 1103, 1167, 1231, 1295, 1359, 1423, 1487,
+	1551, 1615, 1679, 1743, 1807, 1871, 1935, 1999,
+	2095, 2223, 2351, 2479, 2607, 2735, 2863, 2991,
+	3119, 3247, 3375, 3503, 3631, 3759, 3887, 4015,
+};
+
+/*
+ * This function is described into Taos TSL2550 Designer's Notebook
+ * pages 2, 3.
+ */
+static int tsl2550_calculate_lux(u8 ch0, u8 ch1)
+{
+	unsigned int lux;
+
+	/* Look up count from channel values */
+	u16 c0 = count_lut[ch0];
+	u16 c1 = count_lut[ch1];
+
+	/*
+	 * Calculate ratio.
+	 * Note: the "128" is a scaling factor
+	 */
+	u8 r = 128;
+
+	/* Avoid division by 0 and count 1 cannot be greater than count 0 */
+	if (c1 <= c0)
+		if (c0) {
+			r = c1 * 128 / c0;
+
+			/* Calculate LUX */
+			lux = ((c0 - c1) * ratio_lut[r]) / 256;
+		} else
+			lux = 0;
+	else
+		return -EAGAIN;
+
+	/* LUX range check */
+	return lux > TSL2550_MAX_LUX ? TSL2550_MAX_LUX : lux;
+}
+
+/*
+ * SysFS support
+ */
+
+static ssize_t tsl2550_show_power_state(struct device *dev,
+		struct device_attribute *attr, char *buf)
+{
+	struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev));
+
+	return sprintf(buf, "%u\n", data->power_state);
+}
+
+static ssize_t tsl2550_store_power_state(struct device *dev,
+		struct device_attribute *attr, const char *buf, size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+	unsigned long val;
+	int ret = strict_strtoul(buf, 10, &val);
+
+	if (val < 0 || val > 1 || ret)
+		return -EINVAL;
+
+	mutex_lock(&data->update_lock);
+	ret = tsl2550_set_power_state(client, val);
+	mutex_unlock(&data->update_lock);
+
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
+		   tsl2550_show_power_state, tsl2550_store_power_state);
+
+static ssize_t tsl2550_show_range_max(struct device *dev,
+				     struct device_attribute *attr,
+				     char *buf)
+{
+	struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev));
+	if (data->operating_mode)
+		return sprintf(buf, "9230\n");
+	else
+		return sprintf(buf, "1846\n");
+}
+
+static ssize_t tsl2550_store_range_max(struct device *dev,
+				     struct device_attribute *attr,
+				     const char *buf,
+				     size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+	unsigned long val;
+
+	int ret = strict_strtoul(buf, 10, &val);
+
+	if (ret)
+		return -EINVAL;
+
+	mutex_lock(&data->update_lock);
+	if (val < 1847)
+		ret = tsl2550_set_operating_mode(client, 0);
+	else
+		ret = tsl2550_set_operating_mode(client, 1);
+	mutex_unlock(&data->update_lock);
+
+	if (ret < 0)
+		return ret;
+
+	return count;
+}
+
+static DEVICE_ATTR(illuminance0_range_max, S_IWUSR | S_IRUGO,
+		   tsl2550_show_range_max, tsl2550_store_range_max);
+
+static ssize_t __tsl2550_show_lux(struct i2c_client *client, char *buf)
+{
+	u8 ch0, ch1;
+	int ret;
+
+	ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC0);
+	if (ret < 0)
+		return ret;
+	ch0 = ret;
+
+	ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC1);
+	if (ret < 0)
+		return ret;
+	ch1 = ret;
+
+	/* Do the job */
+	ret = tsl2550_calculate_lux(ch0, ch1);
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "%d\n", ret);
+}
+
+static ssize_t tsl2550_show_lux1_input(struct device *dev,
+			struct device_attribute *attr, char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+	int ret;
+
+	/* No LUX data if not operational */
+	if (!data->power_state)
+		return -EBUSY;
+
+	mutex_lock(&data->update_lock);
+	ret = __tsl2550_show_lux(client, buf);
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+static DEVICE_ATTR(illuminance0, S_IRUGO,
+		   tsl2550_show_lux1_input, NULL);
+
+static struct attribute *tsl2550_attributes[] = {
+	&dev_attr_power_state.attr,
+	&dev_attr_illuminance0_range_max.attr,
+	&dev_attr_illuminance0.attr,
+	NULL
+};
+
+static const struct attribute_group tsl2550_attr_group = {
+	.attrs = tsl2550_attributes,
+};
+
+/*
+ * Initialization function
+ */
+
+static int tsl2550_init_client(struct i2c_client *client)
+{
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+	int err;
+
+	/*
+	 * Probe the chip. To do so we try to power up the device and then to
+	 * read back the 0x03 code
+	 */
+	err = i2c_smbus_read_byte_data(client, TSL2550_POWER_UP);
+	if (err < 0)
+		return err;
+	if (err != TSL2550_POWER_UP)
+		return -ENODEV;
+	data->power_state = 1;
+
+	/* Set the default operating mode */
+	err = i2c_smbus_write_byte(client,
+				   TSL2550_MODE_RANGE[data->operating_mode]);
+	if (err < 0)
+		return err;
+
+	return 0;
+}
+
+/*
+ * I2C init/probing/exit functions
+ */
+
+static struct i2c_driver tsl2550_driver;
+static int __devinit tsl2550_probe(struct i2c_client *client,
+				   const struct i2c_device_id *id)
+{
+	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+	struct tsl2550_data *data;
+	int *opmode, err = 0;
+	char name[9];
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE
+					    | I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
+		err = -EIO;
+		goto exit;
+	}
+
+	data = kzalloc(sizeof(struct tsl2550_data), GFP_KERNEL);
+	if (!data) {
+		err = -ENOMEM;
+		goto exit;
+	}
+	data->client = client;
+	i2c_set_clientdata(client, data);
+
+	/* Check platform data */
+	opmode = client->dev.platform_data;
+	if (opmode) {
+		if (*opmode < 0 || *opmode > 1) {
+			dev_err(&client->dev, "invalid operating_mode (%d)\n",
+					*opmode);
+			err = -EINVAL;
+			goto exit_kfree;
+		}
+		data->operating_mode = *opmode;
+	} else
+		data->operating_mode = 0;	/* default mode is standard */
+	dev_info(&client->dev, "%s operating mode\n",
+			data->operating_mode ? "extended" : "standard");
+
+	mutex_init(&data->update_lock);
+
+	/* Initialize the TSL2550 chip */
+	err = tsl2550_init_client(client);
+	if (err)
+		goto exit_kfree;
+
+	data->id = tsl2550_get_id();
+	if (data->id < 0) {
+		err = data->id;
+		goto exit_kfree;
+	}
+	sprintf(name, "tsl2550_%d", data->id);
+	/* Register sysfs hooks */
+	data->classdev = als_device_register(&client->dev, name);
+	if (IS_ERR(data->classdev)) {
+		err = PTR_ERR(data->classdev);
+		goto exit_free_id;
+	}
+
+	err = sysfs_create_group(&data->classdev->kobj, &tsl2550_attr_group);
+	if (err)
+		goto exit_unreg;
+
+	dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION);
+
+	return 0;
+
+exit_unreg:
+	als_device_unregister(data->classdev);
+exit_free_id:
+	tsl2550_free_id(data->id);
+exit_kfree:
+	kfree(data);
+exit:
+	return err;
+}
+
+static int __devexit tsl2550_remove(struct i2c_client *client)
+{
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+
+	sysfs_remove_group(&data->classdev->kobj, &tsl2550_attr_group);
+	als_device_unregister(data->classdev);
+
+	/* Power down the device */
+	tsl2550_set_power_state(client, 0);
+
+	tsl2550_free_id(data->id);
+
+	kfree(data);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM
+
+static int tsl2550_suspend(struct i2c_client *client, pm_message_t mesg)
+{
+	return tsl2550_set_power_state(client, 0);
+}
+
+static int tsl2550_resume(struct i2c_client *client)
+{
+	return tsl2550_set_power_state(client, 1);
+}
+
+#else
+
+#define tsl2550_suspend		NULL
+#define tsl2550_resume		NULL
+
+#endif /* CONFIG_PM */
+
+static const struct i2c_device_id tsl2550_id[] = {
+	{ "tsl2550", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, tsl2550_id);
+
+static struct i2c_driver tsl2550_driver = {
+	.driver = {
+		.name	= TSL2550_DRV_NAME,
+		.owner	= THIS_MODULE,
+	},
+	.suspend = tsl2550_suspend,
+	.resume	= tsl2550_resume,
+	.probe	= tsl2550_probe,
+	.remove	= __devexit_p(tsl2550_remove),
+	.id_table = tsl2550_id,
+};
+
+static int __init tsl2550_init(void)
+{
+	return i2c_add_driver(&tsl2550_driver);
+}
+
+static void __exit tsl2550_exit(void)
+{
+	i2c_del_driver(&tsl2550_driver);
+}
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti@...ux.it>");
+MODULE_DESCRIPTION("TSL2550 ambient light sensor driver");
+MODULE_LICENSE("GPL");
+MODULE_VERSION(DRIVER_VERSION);
+
+module_init(tsl2550_init);
+module_exit(tsl2550_exit);
diff --git a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig
index f9618f4..626bfcf 100644
--- a/drivers/i2c/chips/Kconfig
+++ b/drivers/i2c/chips/Kconfig
@@ -16,14 +16,4 @@ config DS1682
 	  This driver can also be built as a module.  If so, the module
 	  will be called ds1682.
 
-config SENSORS_TSL2550
-	tristate "Taos TSL2550 ambient light sensor"
-	depends on EXPERIMENTAL
-	help
-	  If you say yes here you get support for the Taos TSL2550
-	  ambient light sensor.
-
-	  This driver can also be built as a module.  If so, the module
-	  will be called tsl2550.
-
 endmenu
diff --git a/drivers/i2c/chips/Makefile b/drivers/i2c/chips/Makefile
index 749cf36..d309782 100644
--- a/drivers/i2c/chips/Makefile
+++ b/drivers/i2c/chips/Makefile
@@ -11,7 +11,6 @@
 #
 
 obj-$(CONFIG_DS1682)		+= ds1682.o
-obj-$(CONFIG_SENSORS_TSL2550)	+= tsl2550.o
 
 ifeq ($(CONFIG_I2C_DEBUG_CHIP),y)
 EXTRA_CFLAGS += -DDEBUG
diff --git a/drivers/i2c/chips/tsl2550.c b/drivers/i2c/chips/tsl2550.c
deleted file mode 100644
index aa96bd2..0000000
--- a/drivers/i2c/chips/tsl2550.c
+++ /dev/null
@@ -1,470 +0,0 @@
-/*
- *  tsl2550.c - Linux kernel modules for ambient light sensor
- *
- *  Copyright (C) 2007 Rodolfo Giometti <giometti@...ux.it>
- *  Copyright (C) 2007 Eurotech S.p.A. <info@...otech.it>
- *
- *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
- */
-
-#include <linux/module.h>
-#include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/i2c.h>
-#include <linux/mutex.h>
-
-#define TSL2550_DRV_NAME	"tsl2550"
-#define DRIVER_VERSION		"1.2"
-
-/*
- * Defines
- */
-
-#define TSL2550_POWER_DOWN		0x00
-#define TSL2550_POWER_UP		0x03
-#define TSL2550_STANDARD_RANGE		0x18
-#define TSL2550_EXTENDED_RANGE		0x1d
-#define TSL2550_READ_ADC0		0x43
-#define TSL2550_READ_ADC1		0x83
-
-/*
- * Structs
- */
-
-struct tsl2550_data {
-	struct i2c_client *client;
-	struct mutex update_lock;
-
-	unsigned int power_state : 1;
-	unsigned int operating_mode : 1;
-};
-
-/*
- * Global data
- */
-
-static const u8 TSL2550_MODE_RANGE[2] = {
-	TSL2550_STANDARD_RANGE, TSL2550_EXTENDED_RANGE,
-};
-
-/*
- * Management functions
- */
-
-static int tsl2550_set_operating_mode(struct i2c_client *client, int mode)
-{
-	struct tsl2550_data *data = i2c_get_clientdata(client);
-
-	int ret = i2c_smbus_write_byte(client, TSL2550_MODE_RANGE[mode]);
-
-	data->operating_mode = mode;
-
-	return ret;
-}
-
-static int tsl2550_set_power_state(struct i2c_client *client, int state)
-{
-	struct tsl2550_data *data = i2c_get_clientdata(client);
-	int ret;
-
-	if (state == 0)
-		ret = i2c_smbus_write_byte(client, TSL2550_POWER_DOWN);
-	else {
-		ret = i2c_smbus_write_byte(client, TSL2550_POWER_UP);
-
-		/* On power up we should reset operating mode also... */
-		tsl2550_set_operating_mode(client, data->operating_mode);
-	}
-
-	data->power_state = state;
-
-	return ret;
-}
-
-static int tsl2550_get_adc_value(struct i2c_client *client, u8 cmd)
-{
-	int ret;
-
-	ret = i2c_smbus_read_byte_data(client, cmd);
-	if (ret < 0)
-		return ret;
-	if (!(ret & 0x80))
-		return -EAGAIN;
-	return ret & 0x7f;	/* remove the "valid" bit */
-}
-
-/*
- * LUX calculation
- */
-
-#define	TSL2550_MAX_LUX		1846
-
-static const u8 ratio_lut[] = {
-	100, 100, 100, 100, 100, 100, 100, 100,
-	100, 100, 100, 100, 100, 100, 99, 99,
-	99, 99, 99, 99, 99, 99, 99, 99,
-	99, 99, 99, 98, 98, 98, 98, 98,
-	98, 98, 97, 97, 97, 97, 97, 96,
-	96, 96, 96, 95, 95, 95, 94, 94,
-	93, 93, 93, 92, 92, 91, 91, 90,
-	89, 89, 88, 87, 87, 86, 85, 84,
-	83, 82, 81, 80, 79, 78, 77, 75,
-	74, 73, 71, 69, 68, 66, 64, 62,
-	60, 58, 56, 54, 52, 49, 47, 44,
-	42, 41, 40, 40, 39, 39, 38, 38,
-	37, 37, 37, 36, 36, 36, 35, 35,
-	35, 35, 34, 34, 34, 34, 33, 33,
-	33, 33, 32, 32, 32, 32, 32, 31,
-	31, 31, 31, 31, 30, 30, 30, 30,
-	30,
-};
-
-static const u16 count_lut[] = {
-	0, 1, 2, 3, 4, 5, 6, 7,
-	8, 9, 10, 11, 12, 13, 14, 15,
-	16, 18, 20, 22, 24, 26, 28, 30,
-	32, 34, 36, 38, 40, 42, 44, 46,
-	49, 53, 57, 61, 65, 69, 73, 77,
-	81, 85, 89, 93, 97, 101, 105, 109,
-	115, 123, 131, 139, 147, 155, 163, 171,
-	179, 187, 195, 203, 211, 219, 227, 235,
-	247, 263, 279, 295, 311, 327, 343, 359,
-	375, 391, 407, 423, 439, 455, 471, 487,
-	511, 543, 575, 607, 639, 671, 703, 735,
-	767, 799, 831, 863, 895, 927, 959, 991,
-	1039, 1103, 1167, 1231, 1295, 1359, 1423, 1487,
-	1551, 1615, 1679, 1743, 1807, 1871, 1935, 1999,
-	2095, 2223, 2351, 2479, 2607, 2735, 2863, 2991,
-	3119, 3247, 3375, 3503, 3631, 3759, 3887, 4015,
-};
-
-/*
- * This function is described into Taos TSL2550 Designer's Notebook
- * pages 2, 3.
- */
-static int tsl2550_calculate_lux(u8 ch0, u8 ch1)
-{
-	unsigned int lux;
-
-	/* Look up count from channel values */
-	u16 c0 = count_lut[ch0];
-	u16 c1 = count_lut[ch1];
-
-	/*
-	 * Calculate ratio.
-	 * Note: the "128" is a scaling factor
-	 */
-	u8 r = 128;
-
-	/* Avoid division by 0 and count 1 cannot be greater than count 0 */
-	if (c1 <= c0)
-		if (c0) {
-			r = c1 * 128 / c0;
-
-			/* Calculate LUX */
-			lux = ((c0 - c1) * ratio_lut[r]) / 256;
-		} else
-			lux = 0;
-	else
-		return -EAGAIN;
-
-	/* LUX range check */
-	return lux > TSL2550_MAX_LUX ? TSL2550_MAX_LUX : lux;
-}
-
-/*
- * SysFS support
- */
-
-static ssize_t tsl2550_show_power_state(struct device *dev,
-		struct device_attribute *attr, char *buf)
-{
-	struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev));
-
-	return sprintf(buf, "%u\n", data->power_state);
-}
-
-static ssize_t tsl2550_store_power_state(struct device *dev,
-		struct device_attribute *attr, const char *buf, size_t count)
-{
-	struct i2c_client *client = to_i2c_client(dev);
-	struct tsl2550_data *data = i2c_get_clientdata(client);
-	unsigned long val = simple_strtoul(buf, NULL, 10);
-	int ret;
-
-	if (val < 0 || val > 1)
-		return -EINVAL;
-
-	mutex_lock(&data->update_lock);
-	ret = tsl2550_set_power_state(client, val);
-	mutex_unlock(&data->update_lock);
-
-	if (ret < 0)
-		return ret;
-
-	return count;
-}
-
-static DEVICE_ATTR(power_state, S_IWUSR | S_IRUGO,
-		   tsl2550_show_power_state, tsl2550_store_power_state);
-
-static ssize_t tsl2550_show_operating_mode(struct device *dev,
-		struct device_attribute *attr, char *buf)
-{
-	struct tsl2550_data *data = i2c_get_clientdata(to_i2c_client(dev));
-
-	return sprintf(buf, "%u\n", data->operating_mode);
-}
-
-static ssize_t tsl2550_store_operating_mode(struct device *dev,
-		struct device_attribute *attr, const char *buf, size_t count)
-{
-	struct i2c_client *client = to_i2c_client(dev);
-	struct tsl2550_data *data = i2c_get_clientdata(client);
-	unsigned long val = simple_strtoul(buf, NULL, 10);
-	int ret;
-
-	if (val < 0 || val > 1)
-		return -EINVAL;
-
-	if (data->power_state == 0)
-		return -EBUSY;
-
-	mutex_lock(&data->update_lock);
-	ret = tsl2550_set_operating_mode(client, val);
-	mutex_unlock(&data->update_lock);
-
-	if (ret < 0)
-		return ret;
-
-	return count;
-}
-
-static DEVICE_ATTR(operating_mode, S_IWUSR | S_IRUGO,
-		   tsl2550_show_operating_mode, tsl2550_store_operating_mode);
-
-static ssize_t __tsl2550_show_lux(struct i2c_client *client, char *buf)
-{
-	u8 ch0, ch1;
-	int ret;
-
-	ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC0);
-	if (ret < 0)
-		return ret;
-	ch0 = ret;
-
-	ret = tsl2550_get_adc_value(client, TSL2550_READ_ADC1);
-	if (ret < 0)
-		return ret;
-	ch1 = ret;
-
-	/* Do the job */
-	ret = tsl2550_calculate_lux(ch0, ch1);
-	if (ret < 0)
-		return ret;
-
-	return sprintf(buf, "%d\n", ret);
-}
-
-static ssize_t tsl2550_show_lux1_input(struct device *dev,
-			struct device_attribute *attr, char *buf)
-{
-	struct i2c_client *client = to_i2c_client(dev);
-	struct tsl2550_data *data = i2c_get_clientdata(client);
-	int ret;
-
-	/* No LUX data if not operational */
-	if (!data->power_state)
-		return -EBUSY;
-
-	mutex_lock(&data->update_lock);
-	ret = __tsl2550_show_lux(client, buf);
-	mutex_unlock(&data->update_lock);
-
-	return ret;
-}
-
-static DEVICE_ATTR(lux1_input, S_IRUGO,
-		   tsl2550_show_lux1_input, NULL);
-
-static struct attribute *tsl2550_attributes[] = {
-	&dev_attr_power_state.attr,
-	&dev_attr_operating_mode.attr,
-	&dev_attr_lux1_input.attr,
-	NULL
-};
-
-static const struct attribute_group tsl2550_attr_group = {
-	.attrs = tsl2550_attributes,
-};
-
-/*
- * Initialization function
- */
-
-static int tsl2550_init_client(struct i2c_client *client)
-{
-	struct tsl2550_data *data = i2c_get_clientdata(client);
-	int err;
-
-	/*
-	 * Probe the chip. To do so we try to power up the device and then to
-	 * read back the 0x03 code
-	 */
-	err = i2c_smbus_read_byte_data(client, TSL2550_POWER_UP);
-	if (err < 0)
-		return err;
-	if (err != TSL2550_POWER_UP)
-		return -ENODEV;
-	data->power_state = 1;
-
-	/* Set the default operating mode */
-	err = i2c_smbus_write_byte(client,
-				   TSL2550_MODE_RANGE[data->operating_mode]);
-	if (err < 0)
-		return err;
-
-	return 0;
-}
-
-/*
- * I2C init/probing/exit functions
- */
-
-static struct i2c_driver tsl2550_driver;
-static int __devinit tsl2550_probe(struct i2c_client *client,
-				   const struct i2c_device_id *id)
-{
-	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
-	struct tsl2550_data *data;
-	int *opmode, err = 0;
-
-	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_WRITE_BYTE
-					    | I2C_FUNC_SMBUS_READ_BYTE_DATA)) {
-		err = -EIO;
-		goto exit;
-	}
-
-	data = kzalloc(sizeof(struct tsl2550_data), GFP_KERNEL);
-	if (!data) {
-		err = -ENOMEM;
-		goto exit;
-	}
-	data->client = client;
-	i2c_set_clientdata(client, data);
-
-	/* Check platform data */
-	opmode = client->dev.platform_data;
-	if (opmode) {
-		if (*opmode < 0 || *opmode > 1) {
-			dev_err(&client->dev, "invalid operating_mode (%d)\n",
-					*opmode);
-			err = -EINVAL;
-			goto exit_kfree;
-		}
-		data->operating_mode = *opmode;
-	} else
-		data->operating_mode = 0;	/* default mode is standard */
-	dev_info(&client->dev, "%s operating mode\n",
-			data->operating_mode ? "extended" : "standard");
-
-	mutex_init(&data->update_lock);
-
-	/* Initialize the TSL2550 chip */
-	err = tsl2550_init_client(client);
-	if (err)
-		goto exit_kfree;
-
-	/* Register sysfs hooks */
-	err = sysfs_create_group(&client->dev.kobj, &tsl2550_attr_group);
-	if (err)
-		goto exit_kfree;
-
-	dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION);
-
-	return 0;
-
-exit_kfree:
-	kfree(data);
-exit:
-	return err;
-}
-
-static int __devexit tsl2550_remove(struct i2c_client *client)
-{
-	sysfs_remove_group(&client->dev.kobj, &tsl2550_attr_group);
-
-	/* Power down the device */
-	tsl2550_set_power_state(client, 0);
-
-	kfree(i2c_get_clientdata(client));
-
-	return 0;
-}
-
-#ifdef CONFIG_PM
-
-static int tsl2550_suspend(struct i2c_client *client, pm_message_t mesg)
-{
-	return tsl2550_set_power_state(client, 0);
-}
-
-static int tsl2550_resume(struct i2c_client *client)
-{
-	return tsl2550_set_power_state(client, 1);
-}
-
-#else
-
-#define tsl2550_suspend		NULL
-#define tsl2550_resume		NULL
-
-#endif /* CONFIG_PM */
-
-static const struct i2c_device_id tsl2550_id[] = {
-	{ "tsl2550", 0 },
-	{ }
-};
-MODULE_DEVICE_TABLE(i2c, tsl2550_id);
-
-static struct i2c_driver tsl2550_driver = {
-	.driver = {
-		.name	= TSL2550_DRV_NAME,
-		.owner	= THIS_MODULE,
-	},
-	.suspend = tsl2550_suspend,
-	.resume	= tsl2550_resume,
-	.probe	= tsl2550_probe,
-	.remove	= __devexit_p(tsl2550_remove),
-	.id_table = tsl2550_id,
-};
-
-static int __init tsl2550_init(void)
-{
-	return i2c_add_driver(&tsl2550_driver);
-}
-
-static void __exit tsl2550_exit(void)
-{
-	i2c_del_driver(&tsl2550_driver);
-}
-
-MODULE_AUTHOR("Rodolfo Giometti <giometti@...ux.it>");
-MODULE_DESCRIPTION("TSL2550 ambient light sensor driver");
-MODULE_LICENSE("GPL");
-MODULE_VERSION(DRIVER_VERSION);
-
-module_init(tsl2550_init);
-module_exit(tsl2550_exit);
-- 
1.6.3.3
--
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