[PATCH] i2c: support for mma7455l 3-Axis digital low-g accelerometer.

[PATCH] i2c: support for mma7455l 3-Axis digital low-g accelerometer.

[Rodolfo Giometti]

From: Rodolfo Giometti <giometti-k2GhghHVRtY@public.gmane.org>

Signed-off-by: Rodolfo Giometti <giometti-k2GhghHVRtY@public.gmane.org>
---
 drivers/i2c/chips/Kconfig    |   10 +
 drivers/i2c/chips/Makefile   |    1 +
 drivers/i2c/chips/mma7455l.c |  372 ++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 383 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/chips/mma7455l.c

diff --git a/drivers/i2c/chips/Kconfig b/drivers/i2c/chips/Kconfig
index 7c5a497..815fca4 100644
--- a/drivers/i2c/chips/Kconfig
+++ b/drivers/i2c/chips/Kconfig
@@ -112,4 +112,14 @@ config SENSORS_HMC6343
 	  This driver can also be built as a module.  If so, the module
 	  will be called hmc6343.
 
+config SENSORS_MMA7455L
+	tristate "Freescale 2g/4g/8g 3-Axis low-g accelerometer"
+	depends on EXPERIMENTAL
+	help
+	  If you say yes here you get support for the Freescale 2g/4g/8g
+	  3-Axis low-g accelerometer.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called mma7455l.
+
 endmenu
diff --git a/drivers/i2c/chips/Makefile b/drivers/i2c/chips/Makefile
index a6c7305..631207e 100644
--- a/drivers/i2c/chips/Makefile
+++ b/drivers/i2c/chips/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_PCF8575)		+= pcf8575.o
 obj-$(CONFIG_SENSORS_PCF8591)	+= pcf8591.o
 obj-$(CONFIG_SENSORS_TSL2550)	+= tsl2550.o
 obj-$(CONFIG_SENSORS_HMC6343)	+= hmc6343.o
+obj-$(CONFIG_SENSORS_MMA7455L)	+= mma7455l.o
 
 ifeq ($(CONFIG_I2C_DEBUG_CHIP),y)
 EXTRA_CFLAGS += -DDEBUG
diff --git a/drivers/i2c/chips/mma7455l.c b/drivers/i2c/chips/mma7455l.c
new file mode 100644
index 0000000..01a9c19
--- /dev/null
+++ b/drivers/i2c/chips/mma7455l.c
@@ -0,0 +1,372 @@
+/*
+ *  mma7455l.c - driver for 3-Axis digital low-g accelerometer
+ *
+ *  Copyright (C) 2008-2009 Rodolfo Giometti <giometti-k2GhghHVRtY@public.gmane.org>
+ *  Copyright (C) 2008-2009 Eurotech S.p.A. <info-ymFC7zkAqBI1GQ1Ptb7lUw@public.gmane.org>
+ *
+ *  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/delay.h>
+
+#include <linux/i2c/mma7455l.h>
+
+#define DRIVER_VERSION		"0.40.0"
+
+/*
+ * Defines
+ */
+
+#define ACCEL_DATA		0x00
+#define MCTL			0x16
+#define    GSEL_SHIFT		   2
+#define    GSEL_MASK		   (3 << 2)
+#define    GSEL_NOP		   3
+#define    MOD_SHIFT		   0
+#define    MOD_MASK		   (3 << 0)
+
+static char *mode_lut[] = {
+	"standby", "measurement", "level", "pulse",
+};
+
+/*
+ * Structs
+ */
+
+struct maa7455l_data {
+	struct mutex update_lock;
+};
+
+/*
+ * Management functions
+ */
+
+static int get_angle(struct i2c_client *client, u8 type, s16 *a)
+{
+	struct maa7455l_data *data = i2c_get_clientdata(client);
+	struct i2c_msg msg1[] = {
+		{ client->addr, 0, 1, &type },
+	};
+	u8 d[6];
+	struct i2c_msg msg2[] = {
+		{ client->addr, I2C_M_RD, 6, d },
+	};
+	int ret;
+
+	mutex_lock(&data->update_lock);
+
+	/* FIXME: should check DRDY flag */
+
+	ret = i2c_transfer(client->adapter, msg1, 1);
+	if (ret < 0)
+		goto exit;
+
+	mdelay(1);
+
+	ret = i2c_transfer(client->adapter, msg2, 1);
+	if (ret < 0)
+		goto exit;
+	ret = 0;
+exit:
+	mutex_unlock(&data->update_lock);
+
+	a[0] = (s16) ((d[1] << 8) | d[0]);
+	a[1] = (s16) ((d[3] << 8) | d[2]);
+	a[2] = (s16) ((d[5] << 8) | d[4]);
+
+	return ret;
+}
+
+static int write_g_select(struct i2c_client *client, int val)
+{
+	struct maa7455l_data *data = i2c_get_clientdata(client);
+	int ret;
+
+	switch (val) {
+	case 2:
+		val = GSEL_2;
+		break;
+	case 4:
+		val = GSEL_4;
+		break;
+	case 8:
+		val = GSEL_8;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	mutex_lock(&data->update_lock);
+
+	ret = i2c_smbus_read_byte_data(client, MCTL);
+	if (ret < 0)
+		goto exit;
+
+	ret &= ~GSEL_MASK;
+	ret |= val << GSEL_SHIFT;
+
+	ret = i2c_smbus_write_byte_data(client, MCTL, ret);
+	if (ret < 0)
+		goto exit;
+	ret = 0;
+exit:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+static int write_mode(struct i2c_client *client, int val)
+{
+	struct maa7455l_data *data = i2c_get_clientdata(client);
+	int ret;
+
+	if (val < 0 || val > 3)
+		return -EINVAL;
+
+	mutex_lock(&data->update_lock);
+	ret = i2c_smbus_read_byte_data(client, MCTL);
+	if (ret < 0)
+		goto exit;
+
+	ret &= ~MOD_MASK;
+	ret |= val << MOD_SHIFT;
+
+	ret = i2c_smbus_write_byte_data(client, MCTL, ret);
+	if (ret < 0)
+		goto exit;
+	ret = 0;
+exit:
+	mutex_unlock(&data->update_lock);
+
+	return ret;
+}
+
+/*
+ * SysFS support
+ */
+
+static ssize_t show_accel(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	s16 data[3];
+	int ret = get_angle(to_i2c_client(dev), ACCEL_DATA, data);
+	if (ret < 0)
+		return ret;
+
+	return sprintf(buf, "Ax:%d,Ay:%d,Az:%d\n", data[0], data[1], data[2]);
+}
+
+static DEVICE_ATTR(accel, S_IRUGO, show_accel, NULL);
+
+static ssize_t show_mode(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	int ret = i2c_smbus_read_byte_data(to_i2c_client(dev), MCTL);
+	if (ret < 0)
+		return ret;
+
+	ret = (ret & MOD_MASK) >> MOD_SHIFT;
+	return sprintf(buf, "%s", mode_lut[ret]);
+}
+
+static ssize_t store_mode(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	char *p;
+	int len, i, ret;
+
+	/* Remove '\n' from buf */
+	p = memchr(buf, '\n', count);
+	len = p ? p - buf : count;
+
+	for (i = 0; i < 4; i++)
+		if (!strncmp(buf, mode_lut[i], len))
+			break;
+	if (i >= 4)
+		return -EINVAL;
+
+	ret = write_mode(to_i2c_client(dev), i);
+	return ret ? ret : count;
+}
+
+static DEVICE_ATTR(mode, S_IWUSR | S_IRUGO, show_mode, store_mode);
+
+static ssize_t show_g_select(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	int ret = i2c_smbus_read_byte_data(to_i2c_client(dev), MCTL);
+	if (ret < 0)
+		return ret;
+
+	ret = (ret & GSEL_MASK) >> GSEL_SHIFT;
+	if (ret == GSEL_NOP)
+		return -EINVAL;
+
+	return sprintf(buf, "%d", ret == GSEL_8 ? 8 : (ret == GSEL_2 ? 2 : 4));
+}
+
+static ssize_t store_g_select(struct device *dev,
+				struct device_attribute *attr,
+				const char *buf, size_t count)
+{
+	long val;
+	int ret = strict_strtol(buf, 10, &val);
+	if (ret)
+		return -EINVAL;
+
+	ret = write_g_select(to_i2c_client(dev), val);
+	return ret ? ret : count;
+}
+
+static DEVICE_ATTR(g_select, S_IWUSR | S_IRUGO, show_g_select, store_g_select);
+
+static struct attribute *mma7455l_attributes[] = {
+	&dev_attr_accel.attr,
+	&dev_attr_g_select.attr,
+	&dev_attr_mode.attr,
+	NULL
+};
+
+static const struct attribute_group mma7455l_attr_group = {
+	.attrs = mma7455l_attributes,
+};
+
+/*
+ * Initialization function
+ */
+
+static int mma7455l_init_client(struct i2c_client *client,
+				struct mma7455l_platform_data *pdata)
+{
+	int ret;
+
+	/* Set the platform defaults */
+	ret = write_g_select(client, pdata->g_select);
+	if (ret)
+		dev_warn(&client->dev, "unable to init g selct to %d\n",
+				pdata->g_select);
+	ret = write_mode(client, pdata->mode);
+	if (ret)
+		dev_warn(&client->dev, "unable to init mode to %d\n",
+				pdata->mode);
+
+	return 0;
+}
+
+/*
+ * I2C init/probing/exit functions
+ */
+
+static struct mma7455l_platform_data defs;	/* all values are set to '0' */
+
+static struct i2c_driver mma7455l_driver;
+static int __devinit mma7455l_probe(struct i2c_client *client,
+					const struct i2c_device_id *id)
+{
+	struct i2c_adapter *adapter = to_i2c_adapter(client->dev.parent);
+	struct maa7455l_data *data;
+	struct mma7455l_platform_data *pdata;
+	int ret = 0;
+
+	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE
+				     | I2C_FUNC_SMBUS_WRITE_BYTE_DATA)) {
+		ret = -EIO;
+		goto exit;
+	}
+
+	data = kzalloc(sizeof(struct maa7455l_data), GFP_KERNEL);
+	if (!data) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+	i2c_set_clientdata(client, data);
+
+	/* Check platform data */
+	pdata = client->dev.platform_data;
+	if (!pdata)
+		pdata = &defs;
+	dev_info(&client->dev, "g select %d\n", pdata->g_select);
+	dev_info(&client->dev, "mode %d\n", pdata->mode);
+
+	mutex_init(&data->update_lock);
+
+	/* Initialize the MMA7455L chip */
+	ret = mma7455l_init_client(client, pdata);
+	if (ret)
+		goto exit_kfree;
+
+	/* Register sysfs hooks */
+	ret = sysfs_create_group(&client->dev.kobj, &mma7455l_attr_group);
+	if (ret)
+		goto exit_kfree;
+		goto exit;
+
+	dev_info(&client->dev, "support ver. %s enabled\n", DRIVER_VERSION);
+
+	return 0;
+
+exit_kfree:
+	kfree(data);
+exit:
+	return ret;
+}
+
+static int __devexit mma7455l_remove(struct i2c_client *client)
+{
+	sysfs_remove_group(&client->dev.kobj, &mma7455l_attr_group);
+
+	kfree(i2c_get_clientdata(client));
+
+	return 0;
+}
+
+static const struct i2c_device_id mma7455l_id[] = {
+	{ "mma7455l", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, mma7455l_id);
+
+static struct i2c_driver mma7455l_driver = {
+	.driver = {
+		.name	= "mma7455l",
+		.owner	= THIS_MODULE,
+	},
+	.probe	= mma7455l_probe,
+	.remove	= __devexit_p(mma7455l_remove),
+	.id_table = mma7455l_id,
+};
+
+static int __init mma7455l_init(void)
+{
+	return i2c_add_driver(&mma7455l_driver);
+}
+
+static void __exit mma7455l_exit(void)
+{
+	i2c_del_driver(&mma7455l_driver);
+}
+
+MODULE_AUTHOR("Rodolfo Giometti <giometti-k2GhghHVRtY@public.gmane.org>");
+MODULE_DESCRIPTION("MMA7455L 3-Axis digital low-g accelerometer");
+MODULE_LICENSE("GPL");
+
+module_init(mma7455l_init);
+module_exit(mma7455l_exit);
-- 
1.5.6.3

Re: [PATCH] i2c: support for mma7455l 3-Axis digital low-g accelerometer.

[Akshay Bhat]

Hi Rodolfo,

Where can I get the mma7455l.h header file?


Thanks,
Akshay