Commit 55b951e7 authored by Eric Miao's avatar Eric Miao Committed by Russell King
Browse files

hwmon: add max1111 Low-power Multichannel Serial 8-bit ADCs 



Driver based on corgi_ssp.c and sharpsl_pm.c, previously done by Richard
Purdie and many others.

Now changed to generic HWMON device and expose all the ADC input value
through sysfs.

Signed-off-by: default avatarEric Miao <eric.miao@marvell.com>
Acked-by: default avatarJean Delvare <khali@linux-fr.org>
Signed-off-by: default avatarRussell King <rmk+kernel@arm.linux.org.uk>
parent dd89ccb2

drivers/hwmon/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -540,6 +540,15 @@ config SENSORS_LM93 
	  This driver can also be built as a module.  If so, the module

	  will be called lm93.



config SENSORS_MAX1111

	tristate "Maxim MAX1111 Multichannel, Serial 8-bit ADC chip"

	depends on SPI_MASTER

	help

	  Say y here to support Maxim's MAX1111 ADC chips.



	  This driver can also be built as a module.  If so, the module

	  will be called max1111.



config SENSORS_MAX1619

	tristate "Maxim MAX1619 sensor chip"

	depends on I2C

drivers/hwmon/Makefile

+1 −0
Original line number Diff line number Diff line
@@ -59,6 +59,7 @@ obj-$(CONFIG_SENSORS_LM87) += lm87.o 
obj-$(CONFIG_SENSORS_LM90)	+= lm90.o

obj-$(CONFIG_SENSORS_LM92)	+= lm92.o

obj-$(CONFIG_SENSORS_LM93)	+= lm93.o

obj-$(CONFIG_SENSORS_MAX1111)	+= max1111.o

obj-$(CONFIG_SENSORS_MAX1619)	+= max1619.o

obj-$(CONFIG_SENSORS_MAX6650)	+= max6650.o

obj-$(CONFIG_SENSORS_PC87360)	+= pc87360.o

drivers/hwmon/max1111.c

0 → 100644
+231 −0
Original line number Diff line number Diff line 
/*

 * max1111.c - +2.7V, Low-Power, Multichannel, Serial 8-bit ADCs

 *

 * Based on arch/arm/mach-pxa/corgi_ssp.c

 *

 * Copyright (C) 2004-2005 Richard Purdie

 *

 * Copyright (C) 2008 Marvell International Ltd.

 * 	Eric Miao <eric.miao@marvell.com>

 *

 *  This program is free software; you can redistribute it and/or modify

 *  it under the terms of the GNU General Public License version 2 as

 *  publishhed by the Free Software Foundation.

 */



#include <linux/module.h>

#include <linux/kernel.h>

#include <linux/init.h>

#include <linux/err.h>

#include <linux/hwmon.h>

#include <linux/hwmon-sysfs.h>

#include <linux/spi/spi.h>



#define MAX1111_TX_BUF_SIZE	1

#define MAX1111_RX_BUF_SIZE	2



/* MAX1111 Commands */

#define MAX1111_CTRL_PD0      (1u << 0)

#define MAX1111_CTRL_PD1      (1u << 1)

#define MAX1111_CTRL_SGL      (1u << 2)

#define MAX1111_CTRL_UNI      (1u << 3)

#define MAX1111_CTRL_SEL_SH   (5)	/* NOTE: bit 4 is ignored */

#define MAX1111_CTRL_STR      (1u << 7)



struct max1111_data {

	struct spi_device	*spi;

	struct device		*hwmon_dev;

	struct spi_message	msg;

	struct spi_transfer	xfer[2];

	uint8_t *tx_buf;

	uint8_t *rx_buf;

};



static int max1111_read(struct device *dev, int channel)

{

	struct max1111_data *data = dev_get_drvdata(dev);

	uint8_t v1, v2;

	int err;



	data->tx_buf[0] = (channel << MAX1111_CTRL_SEL_SH) |

		MAX1111_CTRL_PD0 | MAX1111_CTRL_PD1 |

		MAX1111_CTRL_SGL | MAX1111_CTRL_UNI | MAX1111_CTRL_STR;



	err = spi_sync(data->spi, &data->msg);

	if (err < 0) {

		dev_err(dev, "spi_sync failed with %d\n", err);

		return err;

	}



	v1 = data->rx_buf[0];

	v2 = data->rx_buf[1];



	if ((v1 & 0xc0) || (v2 & 0x3f))

		return -EINVAL;



	return (v1 << 2) | (v2 >> 6);

}



/*

 * NOTE: SPI devices do not have a default 'name' attribute, which is

 * likely to be used by hwmon applications to distinguish between

 * different devices, explicitly add a name attribute here.

 */

static ssize_t show_name(struct device *dev,

			 struct device_attribute *attr, char *buf)

{

	return sprintf(buf, "max1111\n");

}



static ssize_t show_adc(struct device *dev,

			struct device_attribute *attr, char *buf)

{

	int channel = to_sensor_dev_attr(attr)->index;

	int ret;



	ret = max1111_read(dev, channel);

	if (ret < 0)

		return ret;



	return sprintf(buf, "%d\n", ret);

}



#define MAX1111_ADC_ATTR(_id)		\

	SENSOR_DEVICE_ATTR(adc##_id##_in, S_IRUGO, show_adc, NULL, _id)



static DEVICE_ATTR(name, S_IRUGO, show_name, NULL);

static MAX1111_ADC_ATTR(0);

static MAX1111_ADC_ATTR(1);

static MAX1111_ADC_ATTR(2);

static MAX1111_ADC_ATTR(3);



static struct attribute *max1111_attributes[] = {

	&dev_attr_name.attr,

	&sensor_dev_attr_adc0_in.dev_attr.attr,

	&sensor_dev_attr_adc1_in.dev_attr.attr,

	&sensor_dev_attr_adc2_in.dev_attr.attr,

	&sensor_dev_attr_adc3_in.dev_attr.attr,

	NULL,

};



static const struct attribute_group max1111_attr_group = {

	.attrs	= max1111_attributes,

};



static int setup_transfer(struct max1111_data *data)

{

	struct spi_message *m;

	struct spi_transfer *x;



	data->tx_buf = kmalloc(MAX1111_TX_BUF_SIZE, GFP_KERNEL);

	if (!data->tx_buf)

		return -ENOMEM;



	data->rx_buf = kmalloc(MAX1111_RX_BUF_SIZE, GFP_KERNEL);

	if (!data->rx_buf) {

		kfree(data->tx_buf);

		return -ENOMEM;

	}



	m = &data->msg;

	x = &data->xfer[0];



	spi_message_init(m);



	x->tx_buf = &data->tx_buf[0];

	x->len = 1;

	spi_message_add_tail(x, m);



	x++;

	x->rx_buf = &data->rx_buf[0];

	x->len = 2;

	spi_message_add_tail(x, m);



	return 0;

}



static int __devinit max1111_probe(struct spi_device *spi)

{

	struct max1111_data *data;

	int err;



	spi->bits_per_word = 8;

	spi->mode = SPI_MODE_0;

	err = spi_setup(spi);

	if (err < 0)

		return err;



	data = kzalloc(sizeof(struct max1111_data), GFP_KERNEL);

	if (data == NULL) {

		dev_err(&spi->dev, "failed to allocate memory\n");

		return -ENOMEM;

	}



	err = setup_transfer(data);

	if (err)

		goto err_free_data;



	data->spi = spi;

	spi_set_drvdata(spi, data);



	err = sysfs_create_group(&spi->dev.kobj, &max1111_attr_group);

	if (err) {

		dev_err(&spi->dev, "failed to create attribute group\n");

		goto err_free_all;

	}



	data->hwmon_dev = hwmon_device_register(&spi->dev);

	if (IS_ERR(data->hwmon_dev)) {

		dev_err(&spi->dev, "failed to create hwmon device\n");

		err = PTR_ERR(data->hwmon_dev);

		goto err_remove;

	}



	return 0;



err_remove:

	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);

err_free_all:

	kfree(data->rx_buf);

	kfree(data->tx_buf);

err_free_data:

	kfree(data);

	return err;

}



static int __devexit max1111_remove(struct spi_device *spi)

{

	struct max1111_data *data = spi_get_drvdata(spi);



	hwmon_device_unregister(data->hwmon_dev);

	sysfs_remove_group(&spi->dev.kobj, &max1111_attr_group);

	kfree(data->rx_buf);

	kfree(data->tx_buf);

	kfree(data);

	return 0;

}



static struct spi_driver max1111_driver = {

	.driver		= {

		.name	= "max1111",

		.owner	= THIS_MODULE,

	},

	.probe		= max1111_probe,

	.remove		= __devexit_p(max1111_remove),

};



static int __init max1111_init(void)

{

	return spi_register_driver(&max1111_driver);

}

module_init(max1111_init);



static void __exit max1111_exit(void)

{

	spi_unregister_driver(&max1111_driver);

}

module_exit(max1111_exit);



MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");

MODULE_DESCRIPTION("MAX1111 ADC Driver");

MODULE_LICENSE("GPL");

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