hwmon: (adt7410) Add support for the adt7310/adt7320

The adt7310/adt7320 is the SPI version of the adt7410/adt7420. The register map
layout is a bit different, i.e. the register addresses differ between the two
variants, but the bit layouts of the individual registers are identical. So both
chip variants can easily be supported by the same driver. The issue of non
matching register address layouts is solved by a simple look-up table which
translates the I2C addresses to the SPI addresses.

The patch moves the bulk of the adt7410 driver to a common module that will be
shared by the adt7410 and adt7310 drivers. This common module implements the
driver logic and uses a set of virtual functions to perform IO access. The
adt7410 and adt7310 driver modules provide proper implementations of these IO
accessor functions for I2C respective SPI.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Reviewed-by: Hartmut Knaack <knaack.h@gmx.de>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

1 files changed, 123 insertions, 0 deletions

diff --git a/drivers/hwmon/adt7310.c b/drivers/hwmon/adt7310.c
new file mode 100644
index 00000000000..f8ea6292bc7
--- /dev/null
+++ b/drivers/hwmon/adt7310.c
@@ -0,0 +1,123 @@
+/*
+ * ADT7310/ADT7310 digital temperature sensor driver
+ *
+ * Copyright 2012-2013 Analog Devices Inc.
+ *   Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * Licensed under the GPL-2 or later.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/spi/spi.h>
+#include <asm/unaligned.h>
+
+#include "adt7x10.h"
+
+#define ADT7310_STATUS			0
+#define ADT7310_CONFIG			1
+#define ADT7310_TEMPERATURE		2
+#define ADT7310_ID			3
+#define ADT7310_T_CRIT			4
+#define ADT7310_T_HYST			5
+#define ADT7310_T_ALARM_HIGH		6
+#define ADT7310_T_ALARM_LOW		7
+
+static const u8 adt7310_reg_table[] = {
+	[ADT7X10_TEMPERATURE]   = ADT7310_TEMPERATURE,
+	[ADT7X10_STATUS]	= ADT7310_STATUS,
+	[ADT7X10_CONFIG]	= ADT7310_CONFIG,
+	[ADT7X10_T_ALARM_HIGH]	= ADT7310_T_ALARM_HIGH,
+	[ADT7X10_T_ALARM_LOW]	= ADT7310_T_ALARM_LOW,
+	[ADT7X10_T_CRIT]	= ADT7310_T_CRIT,
+	[ADT7X10_T_HYST]	= ADT7310_T_HYST,
+	[ADT7X10_ID]		= ADT7310_ID,
+};
+
+#define ADT7310_CMD_REG_OFFSET	3
+#define ADT7310_CMD_READ	0x40
+
+#define AD7310_COMMAND(reg) (adt7310_reg_table[(reg)] << ADT7310_CMD_REG_OFFSET)
+
+static int adt7310_spi_read_word(struct device *dev, u8 reg)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	int ret;
+
+	ret = spi_w8r16(spi, AD7310_COMMAND(reg) | ADT7310_CMD_READ);
+	if (ret < 0)
+		return ret;
+
+	return be16_to_cpu(ret);
+}
+
+static int adt7310_spi_write_word(struct device *dev, u8 reg, u16 data)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	u8 buf[3];
+
+	buf[0] = AD7310_COMMAND(reg);
+	put_unaligned_be16(data, &buf[1]);
+
+	return spi_write(spi, buf, sizeof(buf));
+}
+
+static int adt7310_spi_read_byte(struct device *dev, u8 reg)
+{
+	struct spi_device *spi = to_spi_device(dev);
+
+	return spi_w8r8(spi, AD7310_COMMAND(reg) | ADT7310_CMD_READ);
+}
+
+static int adt7310_spi_write_byte(struct device *dev, u8 reg,
+	u8 data)
+{
+	struct spi_device *spi = to_spi_device(dev);
+	u8 buf[2];
+
+	buf[0] = AD7310_COMMAND(reg);
+	buf[1] = data;
+
+	return spi_write(spi, buf, sizeof(buf));
+}
+
+static const struct adt7x10_ops adt7310_spi_ops = {
+	.read_word = adt7310_spi_read_word,
+	.write_word = adt7310_spi_write_word,
+	.read_byte = adt7310_spi_read_byte,
+	.write_byte = adt7310_spi_write_byte,
+};
+
+static int adt7310_spi_probe(struct spi_device *spi)
+{
+	return adt7x10_probe(&spi->dev, spi_get_device_id(spi)->name,
+			&adt7310_spi_ops);
+}
+
+static int adt7310_spi_remove(struct spi_device *spi)
+{
+	return adt7x10_remove(&spi->dev);
+}
+
+static const struct spi_device_id adt7310_id[] = {
+	{ "adt7310", 0 },
+	{ "adt7320", 0 },
+	{}
+};
+MODULE_DEVICE_TABLE(spi, adt7310_id);
+
+static struct spi_driver adt7310_driver = {
+	.driver = {
+		.name	= "adt7310",
+		.owner	= THIS_MODULE,
+		.pm	= ADT7X10_DEV_PM_OPS,
+	},
+	.probe		= adt7310_spi_probe,
+	.remove		= adt7310_spi_remove,
+	.id_table	= adt7310_id,
+};
+module_spi_driver(adt7310_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("ADT7310/ADT7320 driver");
+MODULE_LICENSE("GPL");