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Subject[PATCH 03/14] IIO: tsl2561 digital light sensor core support
Date
Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>

This is a pretty minimalist example of an IIO driver.

---
Unlike the existing light sensor driver tsl2550 all
conversion to units is left to userspace.
This is similar to the isl29003 driver.

IIO may in future provide a home for such light sensor
drivers.
---
drivers/iio/Kconfig | 3 +-
drivers/iio/Makefile | 3 +-
drivers/iio/light/Kconfig | 14 ++
drivers/iio/light/Makefile | 5 +
drivers/iio/light/tsl2561.c | 275 +++++++++++++++++++++++++++++++++++++++++++
include/linux/iio/light.h | 12 ++
6 files changed, 310 insertions(+), 2 deletions(-)
create mode 100644 drivers/iio/light/Kconfig
create mode 100644 drivers/iio/light/Makefile
create mode 100644 drivers/iio/light/tsl2561.c
create mode 100644 include/linux/iio/light.h

diff --git a/drivers/iio/Kconfig b/drivers/iio/Kconfig
index ca54ab3..d37859d 100644
--- a/drivers/iio/Kconfig
+++ b/drivers/iio/Kconfig
@@ -10,4 +10,5 @@ menuconfig IIO
number of different physical interfaces (i2c, spi etc). See
Documentation/industrialio for more information.

-source drivers/iio/adc/Kconfig
\ No newline at end of file
+source drivers/iio/adc/Kconfig
+source drivers/iio/light/Kconfig
diff --git a/drivers/iio/Makefile b/drivers/iio/Makefile
index 9d11f64..4e78f98 100644
--- a/drivers/iio/Makefile
+++ b/drivers/iio/Makefile
@@ -5,4 +5,5 @@
obj-$(CONFIG_IIO) += industrialio.o
industrialio-y := industrialio-core.o

-obj-y += adc/
\ No newline at end of file
+obj-y += adc/
+obj-y += light/
\ No newline at end of file
diff --git a/drivers/iio/light/Kconfig b/drivers/iio/light/Kconfig
new file mode 100644
index 0000000..620e249
--- /dev/null
+++ b/drivers/iio/light/Kconfig
@@ -0,0 +1,14 @@
+#
+# Light sensors
+#
+comment "Light sensors"
+ depends on IIO
+
+config TSL2561
+ tristate "TAOS TSL2561 light-to-digital convertor"
+ depends on IIO
+ help
+ Say yes bere to build support for the TAOS light to digital
+ convertor. This chip has two light sensors. One is broadband
+ including infrared whilst the other measures only infrared.
+ Provides direct access via sysfs.
diff --git a/drivers/iio/light/Makefile b/drivers/iio/light/Makefile
new file mode 100644
index 0000000..ccff151
--- /dev/null
+++ b/drivers/iio/light/Makefile
@@ -0,0 +1,5 @@
+#
+# Makefile for industrial I/O Light sensors
+#
+
+obj-$(CONFIG_TSL2561) += tsl2561.o
diff --git a/drivers/iio/light/tsl2561.c b/drivers/iio/light/tsl2561.c
new file mode 100644
index 0000000..db1443c
--- /dev/null
+++ b/drivers/iio/light/tsl2561.c
@@ -0,0 +1,275 @@
+/*
+ * tsl2561.c - Linux kernel modules for light to digital convertor
+ *
+ * Copyright (C) 2008-2009 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.
+ *
+ * Some portions based upon the tsl2550 driver.
+ *
+ * This driver could probably be adapted easily to talk to the tsl2560 (smbus)
+ *
+ * Needs some work to support the events this can generate.
+ * Todo: Implement interrupt handling. Currently a hardware bug means
+ * this isn't available on my test board.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/light.h>
+
+#define TSL2561_CONTROL_REGISTER 0x00
+#define TSL2561_TIMING_REGISTER 0x01
+#define TSL2561_THRESHLOW_LOW_REGISTER 0x02
+#define TSL2561_THRESHLOW_HIGH_REGISTER 0x03
+#define TSL2561_THRESHHIGH_LOW_REGISTER 0x04
+#define TSL2561_THRESHHIGH_HIGH_REGISTER 0x05
+#define TSL2561_INT_CONTROL_REGISTER 0x06
+
+#define TSL2561_INT_REG_INT_OFF 0x00
+#define TSL2561_INT_REG_INT_LEVEL 0x08
+#define TSL2561_INT_REG_INT_SMBUS 0x10
+#define TSL2561_INT_REG_INT_TEST 0x18
+
+#define TSL2561_ID_REGISTER 0x0A
+
+#define TSL2561_DATA_0_LOW 0x0C
+#define TSL2561_DATA_1_LOW 0x0E
+
+/* Control Register Values */
+#define TSL2561_CONT_REG_PWR_ON 0x03
+#define TSL2561_CONT_REG_PWR_OFF 0x00
+
+/**
+ * struct tsl2561_state - device specific state
+ * @indio_dev: the industrialio I/O info structure
+ * @client: i2c client
+ * @command_buf: single command buffer used for all operations
+ * @command_buf_lock: ensure unique access to command_buf
+ */
+struct tsl2561_state {
+ struct iio_dev *indio_dev;
+ struct i2c_client *client;
+ struct tsl2561_command *command_buf;
+ struct mutex command_buf_lock;
+};
+
+/**
+ * struct tsl2561_command - command byte for smbus
+ * @address: register address
+ * @block: is this a block r/w
+ * @word: is this a word r/w
+ * @clear: set to 1 to clear pending interrupt
+ * @cmd: select the command register - always 1.
+ */
+struct tsl2561_command {
+ unsigned int address:4;
+ unsigned int block:1;
+ unsigned int word:1;
+ unsigned int clear:1;
+ unsigned int cmd:1;
+};
+
+static inline void tsl2561_init_command_buf(struct tsl2561_command *buf)
+{
+ buf->address = 0;
+ buf->block = 0;
+ buf->word = 0;
+ buf->clear = 0;
+ buf->cmd = 1;
+}
+
+static ssize_t tsl2561_read_val(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ int ret = 0, data;
+ ssize_t len = 0;
+ struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
+ struct iio_dev *indio_dev = dev_get_drvdata(dev);
+ struct tsl2561_state *st = indio_dev->dev_data;
+
+ mutex_lock(&st->command_buf_lock);
+ st->command_buf->cmd = 1;
+ st->command_buf->word = 1;
+ st->command_buf->address = this_attr->address;
+
+ data = i2c_smbus_read_word_data(st->client, *(char *)(st->command_buf));
+ if (data < 0) {
+ ret = data;
+ goto error_ret;
+ }
+ len = sprintf(buf, "%u\n", data);
+
+error_ret:
+ mutex_unlock(&st->command_buf_lock);
+
+ return ret ? ret : len;
+}
+
+static IIO_DEV_ATTR_LIGHT_INFRARED(0, tsl2561_read_val, TSL2561_DATA_0_LOW);
+static IIO_DEV_ATTR_LIGHT_BROAD(0, tsl2561_read_val, TSL2561_DATA_1_LOW);
+
+static struct attribute *tsl2561_attributes[] = {
+ &iio_dev_attr_light_infrared0.dev_attr.attr,
+ &iio_dev_attr_light_broadspectrum0.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group tsl2561_attribute_group = {
+ .attrs = tsl2561_attributes,
+};
+
+static int tsl2561_initialize(struct tsl2561_state *st)
+{
+ int err;
+
+ mutex_lock(&st->command_buf_lock);
+ st->command_buf->word = 0;
+ st->command_buf->block = 0;
+ st->command_buf->address = TSL2561_CONTROL_REGISTER;
+ err = i2c_smbus_write_byte_data(st->client, *(char *)(st->command_buf),
+ TSL2561_CONT_REG_PWR_ON);
+ if (err)
+ goto error_ret;
+
+ st->command_buf->address = TSL2561_INT_CONTROL_REGISTER;
+ err = i2c_smbus_write_byte_data(st->client, *(char *)(st->command_buf),
+ TSL2561_INT_REG_INT_TEST);
+
+error_ret:
+ mutex_unlock(&st->command_buf_lock);
+
+ return err;
+}
+
+static int tsl2561_powerdown(struct i2c_client *client)
+{
+ int err;
+ struct tsl2561_command Command = {
+ .cmd = 1,
+ .clear = 0,
+ .word = 0,
+ .block = 0,
+ .address = TSL2561_CONTROL_REGISTER,
+ };
+
+ err = i2c_smbus_write_byte_data(client, *(char *)(&Command),
+ TSL2561_CONT_REG_PWR_OFF);
+ return (err < 0) ? err : 0;
+}
+static int __devinit tsl2561_probe(struct i2c_client *client,
+ const struct i2c_device_id *id)
+{
+ int ret = 0;
+ struct tsl2561_state *st = kzalloc(sizeof(*st), GFP_KERNEL);
+
+ if (st == NULL) {
+ ret = -ENOMEM;
+ goto error_ret;
+ }
+ i2c_set_clientdata(client, st);
+ st->client = client;
+ mutex_init(&st->command_buf_lock);
+
+ st->command_buf = kmalloc(sizeof(*st->command_buf), GFP_KERNEL);
+ if (st->command_buf == NULL) {
+ ret = -ENOMEM;
+ goto error_free_state;
+ }
+ tsl2561_init_command_buf(st->command_buf);
+
+ st->indio_dev = iio_allocate_device();
+ if (st->indio_dev == NULL) {
+ ret = -ENOMEM;
+ goto error_free_command_buf;
+ }
+ st->indio_dev->attrs = &tsl2561_attribute_group;
+ st->indio_dev->dev.parent = &client->dev;
+ st->indio_dev->dev_data = (void *)(st);
+ st->indio_dev->driver_module = THIS_MODULE;
+ st->indio_dev->modes = INDIO_DIRECT_MODE;
+ ret = iio_device_register(st->indio_dev);
+ if (ret)
+ goto error_free_iiodev;
+
+ /* Intialize the chip */
+ ret = tsl2561_initialize(st);
+ if (ret)
+ goto error_unregister_iiodev;
+
+ return 0;
+error_unregister_iiodev:
+ iio_device_unregister(st->indio_dev);
+error_free_iiodev:
+ iio_free_device(st->indio_dev);
+error_free_command_buf:
+ kfree(st->command_buf);
+error_free_state:
+ kfree(st);
+error_ret:
+ return ret;
+
+}
+
+static int __devexit tsl2561_remove(struct i2c_client *client)
+{
+ struct tsl2561_state *st = i2c_get_clientdata(client);
+
+ iio_device_unregister(st->indio_dev);
+ iio_free_device(st->indio_dev);
+ kfree(st);
+
+ return tsl2561_powerdown(client);
+}
+
+static unsigned short normal_i2c[] = { 0x29, 0x39, 0x49, I2C_CLIENT_END };
+
+I2C_CLIENT_INSMOD;
+
+static const struct i2c_device_id tsl2561_id[] = {
+ { "tsl2561", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, tsl2561_id);
+
+
+static struct i2c_driver tsl2561_driver = {
+ .driver = {
+ .name = "tsl2561",
+ },
+ .probe = tsl2561_probe,
+ .remove = __devexit_p(tsl2561_remove),
+ .id_table = tsl2561_id,
+};
+
+static __init int tsl2561_init(void)
+{
+ return i2c_add_driver(&tsl2561_driver);
+}
+module_init(tsl2561_init);
+
+static __exit void tsl2561_exit(void)
+{
+ i2c_del_driver(&tsl2561_driver);
+}
+module_exit(tsl2561_exit);
+
+MODULE_AUTHOR("Jonathan Cameron <jic23@cam.ac.uk>");
+MODULE_DESCRIPTION("TSL2561 light sensor driver");
+MODULE_LICENSE("GPL");
diff --git a/include/linux/iio/light.h b/include/linux/iio/light.h
new file mode 100644
index 0000000..60a8640
--- /dev/null
+++ b/include/linux/iio/light.h
@@ -0,0 +1,12 @@
+#include <linux/iio/sysfs.h>
+
+/* Light to digital sensor attributes */
+
+#define IIO_DEV_ATTR_LIGHT_INFRARED(_num, _show, _addr) \
+ IIO_DEVICE_ATTR(light_infrared##_num, S_IRUGO, _show, NULL, _addr)
+
+#define IIO_DEV_ATTR_LIGHT_BROAD(_num, _show, _addr) \
+ IIO_DEVICE_ATTR(light_broadspectrum##_num, S_IRUGO, _show, NULL, _addr)
+
+#define IIO_DEV_ATTR_LIGHT_VISIBLE(_num, _show, _addr) \
+ IIO_DEVICE_ATTR(light_visible##_num, S_IRUGO, _show, NULL, _addr)
--
1.6.2


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