[PATCH] tsl2550: Move form i2c/chips to als and update interfaces

* [PATCH] tsl2550: Move form i2c/chips to als and update interfaces
@ 2009-12-12 17:17 Jonathan Cameron
  2010-01-26  9:51 ` Jean Delvare
  0 siblings, 1 reply; 10+ messages in thread
From: Jonathan Cameron @ 2009-12-12 17:17 UTC (permalink / raw)
  To: LKML; +Cc: Jean Delvare, Zhang Rui, giometti


Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
---
 V3. Against current mainline with the addition of the two als patches
 as posted by Amit.

 Changes since V2.

 Couple of bug fixes.

 Change from using illuminance_range_max to exposure_time.  As Jean has
 described, using the range is rather problematic as actual range is
 dependent on the difference in infrared and visible + infrared light
 levels. Thus setting it to a particular value far from guarantees that
 the sensor will be able to read anywhere near the desired range.
 exposure_time brings it's own problems.  For this particular chip there
 are two separate ADC's and no way of separating the proportions of
 time in which light is captured as opposed to when the ADC conversion is
 occurring. Other suggestions for how to handle this would be most welcome.
 At the moment, <800msecs is set to 160msecs, everything else to 800msecs
 which is actually made up of 400msecs on each of the two channels.

 Documentation has been updated appropriately.

 I've also removed the now unnecessary kconfig and makefile form i2c/chips.
 Jean, yell if you would prefer to split that into a separate patch or do
 it yourself.

 Documentation/ABI/testing/sysfs-class-als |    9 +
 drivers/als/Kconfig                       |   14 +
 drivers/als/Makefile                      |    2 +
 drivers/als/tsl2550.c                     |  496 +++++++++++++++++++++++++++++
 drivers/i2c/Kconfig                       |    1 -
 drivers/i2c/Makefile                      |    2 +-
 drivers/i2c/chips/Kconfig                 |   19 --
 drivers/i2c/chips/Makefile                |   18 -
 drivers/i2c/chips/tsl2550.c               |  473 ---------------------------
 9 files changed, 522 insertions(+), 512 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-class-als b/Documentation/ABI/testing/sysfs-class-als
index d3b33f3..732f449 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/.../exposure_time[n]
+Date:		Dec. 2009
+KernelVersion:	2.6.32
+Contact:	Jonathan Cameron <jic23@cam.ac.uk>
+Description:	Sensor exposure time.  In some devices this
+		corresponds to the combined time needed to
+		to internally read several different sensors.
+		Unit: microseconds
+		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..64f7f96
--- /dev/null
+++ b/drivers/als/tsl2550.c
@@ -0,0 +1,496 @@
+/*
+ *  tsl2550.c - Linux kernel modules for ambient light sensor
+ *
+ *  Copyright (C) 2007 Rodolfo Giometti <giometti@linux.it>
+ *  Copyright (C) 2007 Eurotech S.p.A. <info@eurotech.it>
+ *  Copyright (C) 2009 Jonathan Cameron <jic23@cam.ac.uk>
+ *
+ *  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/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;
+	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;
+	if (ret == 0x7f)
+		return -ERANGE;
+	return ret & 0x7f;	/* remove the "valid" bit */
+}
+
+/*
+ * LUX calculation - note the range is dependent on combination
+ * of infrared level and visible light levels.
+ */
+
+#define	TSL2550_MAX_LUX		1568
+
+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 i2c_client *client = to_i2c_client(dev->parent);
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+
+	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->parent);
+	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_exposure(struct device *dev,
+				     struct device_attribute *attr,
+				     char *buf)
+{
+	struct i2c_client *client = to_i2c_client(dev->parent);
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+	if (data->operating_mode)
+		return sprintf(buf, "160000\n");
+	else
+		return sprintf(buf, "800000\n");
+}
+
+static ssize_t tsl2550_store_exposure(struct device *dev,
+				      struct device_attribute *attr,
+				      const char *buf,
+				      size_t count)
+{
+	struct i2c_client *client = to_i2c_client(dev->parent);
+	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 >= 800000)
+		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(exposure_time0, S_IWUSR | S_IRUGO,
+		   tsl2550_show_exposure, tsl2550_store_exposure);
+
+static ssize_t __tsl2550_show_lux(struct i2c_client *client, char *buf)
+{
+	struct tsl2550_data *data = i2c_get_clientdata(client);
+	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;
+	if (data->operating_mode == 1)
+		ret *= 5;
+
+	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->parent);
+	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_exposure_time0.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;
+
+	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 */
+	data->classdev = als_device_register(&client->dev);
+	if (IS_ERR(data->classdev)) {
+		err = PTR_ERR(data->classdev);
+		goto exit_kfree;
+	}
+
+	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_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);
+
+	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@linux.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/Kconfig b/drivers/i2c/Kconfig
index 8d8a00e..5c33a71 100644
--- a/drivers/i2c/Kconfig
+++ b/drivers/i2c/Kconfig
@@ -63,7 +63,6 @@ config I2C_HELPER_AUTO
 
 source drivers/i2c/algos/Kconfig
 source drivers/i2c/busses/Kconfig
-source drivers/i2c/chips/Kconfig
 
 config I2C_DEBUG_CORE
 	bool "I2C Core debugging messages"
diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index ba26e6c..ce5fd62 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -5,7 +5,7 @@
 obj-$(CONFIG_I2C_BOARDINFO)	+= i2c-boardinfo.o
 obj-$(CONFIG_I2C)		+= i2c-core.o
 obj-$(CONFIG_I2C_CHARDEV)	+= i2c-dev.o
-obj-y				+= busses/ chips/ algos/
+obj-y				+= busses/ algos/
 
 ifeq ($(CONFIG_I2C_DEBUG_CORE),y)
 EXTRA_CFLAGS += -DDEBUG
diff --git a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig
deleted file mode 100644
index ae4539d..0000000
--- a/drivers/i2c/chips/Kconfig
+++ /dev/null
@@ -1,19 +0,0 @@
-#
-# Miscellaneous I2C chip drivers configuration
-#
-# *** DEPRECATED! Do not add new entries! See Makefile ***
-#
-
-menu "Miscellaneous I2C Chip support"
-
-config SENSORS_TSL2550
-	tristate "Taos TSL2550 ambient light sensor"
-	depends on EXPERIMENTAL
-	help
-	  If you say yes here you get support for the Taos TSL2550
-	  ambient light sensor.
-
-	  This driver can also be built as a module.  If so, the module
-	  will be called tsl2550.
-
-endmenu
diff --git a/drivers/i2c/chips/Makefile b/drivers/i2c/chips/Makefile
deleted file mode 100644
index fe0af0f..0000000
--- a/drivers/i2c/chips/Makefile
+++ /dev/null
@@ -1,18 +0,0 @@
-#
-# Makefile for miscellaneous I2C chip drivers.
-#
-# Do not add new drivers to this directory! It is DEPRECATED.
-#
-# Device drivers are better grouped according to the functionality they
-# implement rather than to the bus they are connected to. In particular:
-# * Hardware monitoring chip drivers go to drivers/hwmon
-# * RTC chip drivers go to drivers/rtc
-# * I/O expander drivers go to drivers/gpio
-#
-
-obj-$(CONFIG_SENSORS_TSL2550)	+= tsl2550.o
-
-ifeq ($(CONFIG_I2C_DEBUG_CHIP),y)
-EXTRA_CFLAGS += -DDEBUG
-endif
-
diff --git a/drivers/i2c/chips/tsl2550.c b/drivers/i2c/chips/tsl2550.c
deleted file mode 100644
index a0702f3..0000000
--- a/drivers/i2c/chips/tsl2550.c
+++ /dev/null
@@ -1,473 +0,0 @@
-/*
- *  tsl2550.c - Linux kernel modules for ambient light sensor
- *
- *  Copyright (C) 2007 Rodolfo Giometti <giometti@linux.it>
- *  Copyright (C) 2007 Eurotech S.p.A. <info@eurotech.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)
-{
-	struct tsl2550_data *data = i2c_get_clientdata(client);
-	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;
-	if (data->operating_mode == 1)
-		ret *= 5;
-
-	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@linux.it>");
-MODULE_DESCRIPTION("TSL2550 ambient light sensor driver");
-MODULE_LICENSE("GPL");
-MODULE_VERSION(DRIVER_VERSION);
-
-module_init(tsl2550_init);
-module_exit(tsl2550_exit);
-- 
1.6.4.4


^ permalink raw reply related	[flat|nested] 10+ messages in thread