Staging: IIO: DAC: AD5624R: Update to IIO ABI

This driver did not conform with the IIO ABI for such devices.
Also the sysfs files that this driver adds were not complete and
partially un-documented.

Update and document ABI
Change License notice, stick to GPL-v2.
Fix indention style
Add option to specify external reference voltage via the regulator framework.
Add mandatory name attribute
Add mandatory out_scale attribute

Changes since V1:
Refine outY_powerdown_mode description
Remove bonus white line
Signed-off-by: NMichael Hennerich <michael.hennerich@analog.com>
Acked-by: NJonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/staging/iio/Documentation/sysfs-bus-iio

@@ -271,6 +271,38 @@ Description:
 		where a single output sets the value for multiple channels
 		simultaneously.
 
+What:		/sys/bus/iio/devices/deviceX/outY_powerdown_mode
+What:		/sys/bus/iio/devices/deviceX/out_powerdown_mode
+KernelVersion:	2.6.38
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Specifies the output powerdown mode.
+		DAC output stage is disconnected from the amplifier and
+		1kohm_to_gnd: connected to ground via an 1kOhm resistor
+		100kohm_to_gnd: connected to ground via an 100kOhm resistor
+		three_state: left floating
+		For a list of available output power down options read
+		outX_powerdown_mode_available. If Y is not present the
+		mode is shared across all outputs.
+
+What:		/sys/bus/iio/devices/deviceX/outY_powerdown_mode_available
+What:		/sys/bus/iio/devices/deviceX/out_powerdown_mode_available
+KernelVersion:	2.6.38
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Lists all available output power down modes.
+		If Y is not present the mode is shared across all outputs.
+
+What:		/sys/bus/iio/devices/deviceX/outY_powerdown
+What:		/sys/bus/iio/devices/deviceX/out_powerdown
+KernelVersion:	2.6.38
+Contact:	linux-iio@vger.kernel.org
+Description:
+		Writing 1 causes output Y to enter the power down mode specified
+		by the corresponding outY_powerdown_mode. Clearing returns to
+		normal operation. Y may be suppressed if all outputs are
+		controlled together.
+
 What:		/sys/bus/iio/devices/deviceX/deviceX:eventY
 KernelVersion:	2.6.35
 Contact:	linux-iio@vger.kernel.org

drivers/staging/iio/dac/ad5624r.h

+/*
+ * AD5624R SPI DAC driver
+ *
+ * Copyright 2010-2011 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
 #ifndef SPI_AD5624R_H_
 #define SPI_AD5624R_H_
 
-#define AD5624R_DAC_CHANNELS	4
+#define AD5624R_DAC_CHANNELS			4
 
-#define AD5624R_ADDR_DAC0	0x0
-#define AD5624R_ADDR_DAC1	0x1
-#define AD5624R_ADDR_DAC2	0x2
-#define AD5624R_ADDR_DAC3	0x3
-#define AD5624R_ADDR_ALL_DAC	0x7
+#define AD5624R_ADDR_DAC0			0x0
+#define AD5624R_ADDR_DAC1			0x1
+#define AD5624R_ADDR_DAC2			0x2
+#define AD5624R_ADDR_DAC3			0x3
+#define AD5624R_ADDR_ALL_DAC			0x7
 
-#define AD5624R_CMD_WRITE_INPUT_N             0x0
-#define AD5624R_CMD_UPDATE_DAC_N              0x1
-#define AD5624R_CMD_WRITE_INPUT_N_UPDATE_ALL  0x2
-#define AD5624R_CMD_WRITE_INPUT_N_UPDATE_N    0x3
-#define AD5624R_CMD_POWERDOWN_DAC             0x4
-#define AD5624R_CMD_RESET                     0x5
-#define AD5624R_CMD_LDAC_SETUP                0x6
-#define AD5624R_CMD_INTERNAL_REFER_SETUP      0x7
+#define AD5624R_CMD_WRITE_INPUT_N		0x0
+#define AD5624R_CMD_UPDATE_DAC_N		0x1
+#define AD5624R_CMD_WRITE_INPUT_N_UPDATE_ALL	0x2
+#define AD5624R_CMD_WRITE_INPUT_N_UPDATE_N	0x3
+#define AD5624R_CMD_POWERDOWN_DAC		0x4
+#define AD5624R_CMD_RESET			0x5
+#define AD5624R_CMD_LDAC_SETUP			0x6
+#define AD5624R_CMD_INTERNAL_REFER_SETUP	0x7
 
-#endif
+#define AD5624R_LDAC_PWRDN_NONE			0x0
+#define AD5624R_LDAC_PWRDN_1K			0x1
+#define AD5624R_LDAC_PWRDN_100K			0x2
+#define AD5624R_LDAC_PWRDN_3STATE		0x3
+
+/**
+ * struct ad5624r_chip_info - chip specific information
+ * @bits:		accuracy of the DAC in bits
+ * @int_vref_mv:	AD5620/40/60: the internal reference voltage
+ */
+
+struct ad5624r_chip_info {
+	u8				bits;
+	u16				int_vref_mv;
+};
+
+/**
+ * struct ad5446_state - driver instance specific data
+ * @indio_dev:		the industrial I/O device
+ * @us:			spi_device
+ * @chip_info:		chip model specific constants, available modes etc
+ * @reg:		supply regulator
+ * @vref_mv:		actual reference voltage used
+ * @pwr_down_mask	power down mask
+ * @pwr_down_mode	current power down mode
+ */
+
+struct ad5624r_state {
+	struct iio_dev			*indio_dev;
+	struct spi_device		*us;
+	const struct ad5624r_chip_info	*chip_info;
+	struct regulator		*reg;
+	unsigned short			vref_mv;
+	unsigned			pwr_down_mask;
+	unsigned			pwr_down_mode;
+};
+
+/**
+ * ad5624r_supported_device_ids:
+ * The AD5624/44/64 parts are available in different
+ * fixed internal reference voltage options.
+ */
+
+enum ad5624r_supported_device_ids {
+	ID_AD5624R3,
+	ID_AD5644R3,
+	ID_AD5664R3,
+	ID_AD5624R5,
+	ID_AD5644R5,
+	ID_AD5664R5,
+};
+
+#endif /* SPI_AD5624R_H_ */

drivers/staging/iio/dac/ad5624r_spi.c

 /*
  * AD5624R, AD5644R, AD5664R Digital to analog convertors spi driver
  *
- * Copyright 2010 Analog Devices Inc.
+ * Copyright 2010-2011 Analog Devices Inc.
  *
- * Licensed under the GPL-2 or later.
+ * Licensed under the GPL-2.
  */
 
 #include <linux/interrupt.h>
@@ -14,25 +14,38 @@
 #include <linux/spi/spi.h>
 #include <linux/slab.h>
 #include <linux/sysfs.h>
-#include <linux/delay.h>
+#include <linux/regulator/consumer.h>
 
 #include "../iio.h"
 #include "../sysfs.h"
 #include "dac.h"
 #include "ad5624r.h"
 
-/**
- * struct ad5624r_state - device related storage
- * @indio_dev:	associated industrial IO device
- * @us:		spi device
- **/
-struct ad5624r_state {
-	struct iio_dev *indio_dev;
-	struct spi_device *us;
-	int data_len;
-	int ldac_mode;
-	int dac_power_mode[AD5624R_DAC_CHANNELS];
-	int internal_ref;
+static const struct ad5624r_chip_info ad5624r_chip_info_tbl[] = {
+	[ID_AD5624R3] = {
+		.bits = 12,
+		.int_vref_mv = 1250,
+	},
+	[ID_AD5644R3] = {
+		.bits = 14,
+		.int_vref_mv = 1250,
+	},
+	[ID_AD5664R3] = {
+		.bits = 16,
+		.int_vref_mv = 1250,
+	},
+	[ID_AD5624R5] = {
+		.bits = 12,
+		.int_vref_mv = 2500,
+	},
+	[ID_AD5644R5] = {
+		.bits = 14,
+		.int_vref_mv = 2500,
+	},
+	[ID_AD5664R5] = {
+		.bits = 16,
+		.int_vref_mv = 2500,
+	},
 };
 
 static int ad5624r_spi_write(struct spi_device *spi,
@@ -42,11 +55,12 @@ static int ad5624r_spi_write(struct spi_device *spi,
 	u8 msg[3];
 
 	/*
-	 * The input shift register is 24 bits wide. The first two bits are don't care bits.
-	 * The next three are the command bits, C2 to C0, followed by the 3-bit DAC address,
-	 * A2 to A0, and then the 16-, 14-, 12-bit data-word. The data-word comprises the 16-,
-	 * 14-, 12-bit input code followed by 0, 2, or 4 don't care bits, for the AD5664R,
-	 * AD5644R, and AD5624R, respectively.
+	 * The input shift register is 24 bits wide. The first two bits are
+	 * don't care bits. The next three are the command bits, C2 to C0,
+	 * followed by the 3-bit DAC address, A2 to A0, and then the
+	 * 16-, 14-, 12-bit data-word. The data-word comprises the 16-,
+	 * 14-, 12-bit input code followed by 0, 2, or 4 don't care bits,
+	 * for the AD5664R, AD5644R, and AD5624R, respectively.
 	 */
 	data = (0 << 22) | (cmd << 19) | (addr << 16) | (val << (16 - len));
 	msg[0] = data >> 16;
@@ -71,40 +85,43 @@ static ssize_t ad5624r_write_dac(struct device *dev,
 		return ret;
 
 	ret = ad5624r_spi_write(st->us, AD5624R_CMD_WRITE_INPUT_N_UPDATE_N,
-				this_attr->address, readin, st->data_len);
+				this_attr->address, readin,
+				st->chip_info->bits);
 	return ret ? ret : len;
 }
 
-static ssize_t ad5624r_read_ldac_mode(struct device *dev,
+static ssize_t ad5624r_read_powerdown_mode(struct device *dev,
 				      struct device_attribute *attr, char *buf)
 {
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct ad5624r_state *st = indio_dev->dev_data;
 
-	return sprintf(buf, "%x\n", st->ldac_mode);
+	char mode[][15] = {"", "1kohm_to_gnd", "100kohm_to_gnd", "three_state"};
+
+	return sprintf(buf, "%s\n", mode[st->pwr_down_mode]);
 }
 
-static ssize_t ad5624r_write_ldac_mode(struct device *dev,
+static ssize_t ad5624r_write_powerdown_mode(struct device *dev,
 				       struct device_attribute *attr,
 				       const char *buf, size_t len)
 {
-	long readin;
-	int ret;
 	struct iio_dev *indio_dev = dev_get_drvdata(dev);
 	struct ad5624r_state *st = indio_dev->dev_data;
+	int ret;
 
-	ret = strict_strtol(buf, 16, &readin);
-	if (ret)
-		return ret;
-
-	ret = ad5624r_spi_write(st->us, AD5624R_CMD_LDAC_SETUP, 0,
-				readin & 0xF, 16);
-	st->ldac_mode = readin & 0xF;
+	if (sysfs_streq(buf, "1kohm_to_gnd"))
+		st->pwr_down_mode = AD5624R_LDAC_PWRDN_1K;
+	else if (sysfs_streq(buf, "100kohm_to_gnd"))
+		st->pwr_down_mode = AD5624R_LDAC_PWRDN_100K;
+	else if (sysfs_streq(buf, "three_state"))
+		st->pwr_down_mode = AD5624R_LDAC_PWRDN_3STATE;
+	else
+		ret = -EINVAL;
 
 	return ret ? ret : len;
 }
 
-static ssize_t ad5624r_read_dac_power_mode(struct device *dev,
+static ssize_t ad5624r_read_dac_powerdown(struct device *dev,
 					   struct device_attribute *attr,
 					   char *buf)
 {
@@ -112,10 +129,11 @@ static ssize_t ad5624r_read_dac_power_mode(struct device *dev,
 	struct ad5624r_state *st = indio_dev->dev_data;
 	struct iio_dev_attr *this_attr = to_iio_dev_attr(attr);
 
-	return sprintf(buf, "%d\n", st->dac_power_mode[this_attr->address]);
+	return sprintf(buf, "%d\n",
+			!!(st->pwr_down_mask & (1 << this_attr->address)));
 }
 
-static ssize_t ad5624r_write_dac_power_mode(struct device *dev,
+static ssize_t ad5624r_write_dac_powerdown(struct device *dev,
 					    struct device_attribute *attr,
 					    const char *buf, size_t len)
 {
@@ -129,80 +147,82 @@ static ssize_t ad5624r_write_dac_power_mode(struct device *dev,
 	if (ret)
 		return ret;
 
-	ret = ad5624r_spi_write(st->us, AD5624R_CMD_POWERDOWN_DAC, 0,
-				((readin & 0x3) << 4) |
-				(1 << this_attr->address), 16);
+	if (readin == 1)
+		st->pwr_down_mask |= (1 << this_attr->address);
+	else if (!readin)
+		st->pwr_down_mask &= ~(1 << this_attr->address);
+	else
+		ret = -EINVAL;
 
-	st->dac_power_mode[this_attr->address] = readin & 0x3;
+	ret = ad5624r_spi_write(st->us, AD5624R_CMD_POWERDOWN_DAC, 0,
+				(st->pwr_down_mode << 4) |
+				st->pwr_down_mask, 16);
 
 	return ret ? ret : len;
 }
 
-static ssize_t ad5624r_read_internal_ref_mode(struct device *dev,
-					      struct device_attribute *attr,
-					      char *buf)
+static ssize_t ad5624r_show_scale(struct device *dev,
+				struct device_attribute *attr,
+				char *buf)
 {
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
-	struct ad5624r_state *st = indio_dev->dev_data;
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad5624r_state *st = iio_dev_get_devdata(dev_info);
+	/* Corresponds to Vref / 2^(bits) */
+	unsigned int scale_uv = (st->vref_mv * 1000) >> st->chip_info->bits;
 
-	return sprintf(buf, "%d\n", st->internal_ref);
+	return sprintf(buf, "%d.%03d\n", scale_uv / 1000, scale_uv % 1000);
 }
+static IIO_DEVICE_ATTR(out_scale, S_IRUGO, ad5624r_show_scale, NULL, 0);
 
-static ssize_t ad5624r_write_internal_ref_mode(struct device *dev,
-					       struct device_attribute *attr,
-					       const char *buf, size_t len)
+static ssize_t ad5624r_show_name(struct device *dev,
+				 struct device_attribute *attr,
+				 char *buf)
 {
-	long readin;
-	int ret;
-	struct iio_dev *indio_dev = dev_get_drvdata(dev);
-	struct ad5624r_state *st = indio_dev->dev_data;
+	struct iio_dev *dev_info = dev_get_drvdata(dev);
+	struct ad5624r_state *st = iio_dev_get_devdata(dev_info);
 
-	ret = strict_strtol(buf, 10, &readin);
-	if (ret)
-		return ret;
-
-	ret = ad5624r_spi_write(st->us, AD5624R_CMD_INTERNAL_REFER_SETUP, 0,
-				!!readin, 16);
-
-	st->internal_ref = !!readin;
-
-	return ret ? ret : len;
+	return sprintf(buf, "%s\n", spi_get_device_id(st->us)->name);
 }
+static IIO_DEVICE_ATTR(name, S_IRUGO, ad5624r_show_name, NULL, 0);
 
 static IIO_DEV_ATTR_OUT_RAW(0, ad5624r_write_dac, AD5624R_ADDR_DAC0);
 static IIO_DEV_ATTR_OUT_RAW(1, ad5624r_write_dac, AD5624R_ADDR_DAC1);
 static IIO_DEV_ATTR_OUT_RAW(2, ad5624r_write_dac, AD5624R_ADDR_DAC2);
 static IIO_DEV_ATTR_OUT_RAW(3, ad5624r_write_dac, AD5624R_ADDR_DAC3);
 
-static IIO_DEVICE_ATTR(ldac_mode, S_IRUGO | S_IWUSR, ad5624r_read_ldac_mode,
-		       ad5624r_write_ldac_mode, 0);
-static IIO_DEVICE_ATTR(internal_ref, S_IRUGO | S_IWUSR,
-		       ad5624r_read_internal_ref_mode,
-		       ad5624r_write_internal_ref_mode, 0);
+static IIO_DEVICE_ATTR(out_powerdown_mode, S_IRUGO |
+			S_IWUSR, ad5624r_read_powerdown_mode,
+			ad5624r_write_powerdown_mode, 0);
 
-#define IIO_DEV_ATTR_DAC_POWER_MODE(_num, _show, _store, _addr)			\
-	IIO_DEVICE_ATTR(dac_power_mode_##_num, S_IRUGO | S_IWUSR, _show, _store, _addr)
+static IIO_CONST_ATTR(out_powerdown_mode_available,
+			"1kohm_to_gnd 100kohm_to_gnd three_state");
 
-static IIO_DEV_ATTR_DAC_POWER_MODE(0, ad5624r_read_dac_power_mode,
-				   ad5624r_write_dac_power_mode, 0);
-static IIO_DEV_ATTR_DAC_POWER_MODE(1, ad5624r_read_dac_power_mode,
-				   ad5624r_write_dac_power_mode, 1);
-static IIO_DEV_ATTR_DAC_POWER_MODE(2, ad5624r_read_dac_power_mode,
-				   ad5624r_write_dac_power_mode, 2);
-static IIO_DEV_ATTR_DAC_POWER_MODE(3, ad5624r_read_dac_power_mode,
-				   ad5624r_write_dac_power_mode, 3);
+#define IIO_DEV_ATTR_DAC_POWERDOWN(_num, _show, _store, _addr)		\
+	IIO_DEVICE_ATTR(out##_num##_powerdown,				\
+			S_IRUGO | S_IWUSR, _show, _store, _addr)
+
+static IIO_DEV_ATTR_DAC_POWERDOWN(0, ad5624r_read_dac_powerdown,
+				   ad5624r_write_dac_powerdown, 0);
+static IIO_DEV_ATTR_DAC_POWERDOWN(1, ad5624r_read_dac_powerdown,
+				   ad5624r_write_dac_powerdown, 1);
+static IIO_DEV_ATTR_DAC_POWERDOWN(2, ad5624r_read_dac_powerdown,
+				   ad5624r_write_dac_powerdown, 2);
+static IIO_DEV_ATTR_DAC_POWERDOWN(3, ad5624r_read_dac_powerdown,
+				   ad5624r_write_dac_powerdown, 3);
 
 static struct attribute *ad5624r_attributes[] = {
 	&iio_dev_attr_out0_raw.dev_attr.attr,
 	&iio_dev_attr_out1_raw.dev_attr.attr,
 	&iio_dev_attr_out2_raw.dev_attr.attr,
 	&iio_dev_attr_out3_raw.dev_attr.attr,
-	&iio_dev_attr_dac_power_mode_0.dev_attr.attr,
-	&iio_dev_attr_dac_power_mode_1.dev_attr.attr,
-	&iio_dev_attr_dac_power_mode_2.dev_attr.attr,
-	&iio_dev_attr_dac_power_mode_3.dev_attr.attr,
-	&iio_dev_attr_ldac_mode.dev_attr.attr,
-	&iio_dev_attr_internal_ref.dev_attr.attr,
+	&iio_dev_attr_out0_powerdown.dev_attr.attr,
+	&iio_dev_attr_out1_powerdown.dev_attr.attr,
+	&iio_dev_attr_out2_powerdown.dev_attr.attr,
+	&iio_dev_attr_out3_powerdown.dev_attr.attr,
+	&iio_dev_attr_out_powerdown_mode.dev_attr.attr,
+	&iio_const_attr_out_powerdown_mode_available.dev_attr.attr,
+	&iio_dev_attr_out_scale.dev_attr.attr,
+	&iio_dev_attr_name.dev_attr.attr,
 	NULL,
 };
 
@@ -213,7 +233,7 @@ static const struct attribute_group ad5624r_attribute_group = {
 static int __devinit ad5624r_probe(struct spi_device *spi)
 {
 	struct ad5624r_state *st;
-	int ret = 0;
+	int ret, voltage_uv = 0;
 
 	st = kzalloc(sizeof(*st), GFP_KERNEL);
 	if (st == NULL) {
@@ -222,18 +242,30 @@ static int __devinit ad5624r_probe(struct spi_device *spi)
 	}
 	spi_set_drvdata(spi, st);
 
-	st->data_len = spi_get_device_id(spi)->driver_data;
+	st->reg = regulator_get(&spi->dev, "vcc");
+	if (!IS_ERR(st->reg)) {
+		ret = regulator_enable(st->reg);
+		if (ret)
+			goto error_put_reg;
+
+		voltage_uv = regulator_get_voltage(st->reg);
+	}
+
+	st->chip_info =
+		&ad5624r_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+
+	if (voltage_uv)
+		st->vref_mv = voltage_uv / 1000;
+	else
+		st->vref_mv = st->chip_info->int_vref_mv;
 
 	st->us = spi;
 	st->indio_dev = iio_allocate_device();
 	if (st->indio_dev == NULL) {
 		ret = -ENOMEM;
-		goto error_free_st;
+		goto error_disable_reg;
 	}
 	st->indio_dev->dev.parent = &spi->dev;
-	st->indio_dev->num_interrupt_lines = 0;
-	st->indio_dev->event_attrs = NULL;
-
 	st->indio_dev->attrs = &ad5624r_attribute_group;
 	st->indio_dev->dev_data = (void *)(st);
 	st->indio_dev->driver_module = THIS_MODULE;
@@ -243,14 +275,22 @@ static int __devinit ad5624r_probe(struct spi_device *spi)
 	if (ret)
 		goto error_free_dev;
 
-	spi->mode = SPI_MODE_0;
-	spi_setup(spi);
+	ret = ad5624r_spi_write(spi, AD5624R_CMD_INTERNAL_REFER_SETUP, 0,
+				!!voltage_uv, 16);
+	if (ret)
+		goto error_free_dev;
 
 	return 0;
 
 error_free_dev:
 	iio_free_device(st->indio_dev);
-error_free_st:
+error_disable_reg:
+	if (!IS_ERR(st->reg))
+		regulator_disable(st->reg);
+error_put_reg:
+	if (!IS_ERR(st->reg))
+		regulator_put(st->reg);
+
 	kfree(st);
 error_ret:
 	return ret;
@@ -261,15 +301,24 @@ static int __devexit ad5624r_remove(struct spi_device *spi)
 	struct ad5624r_state *st = spi_get_drvdata(spi);
 
 	iio_device_unregister(st->indio_dev);
+
+	if (!IS_ERR(st->reg)) {
+		regulator_disable(st->reg);
+		regulator_put(st->reg);
+	}
+
 	kfree(st);
 
 	return 0;
 }
 
 static const struct spi_device_id ad5624r_id[] = {
-	{"ad5624r", 12},
-	{"ad5644r", 14},
-	{"ad5664r", 16},
+	{"ad5624r3", ID_AD5624R3},
+	{"ad5644r3", ID_AD5644R3},
+	{"ad5664r3", ID_AD5664R3},
+	{"ad5624r5", ID_AD5624R5},
+	{"ad5644r5", ID_AD5644R5},
+	{"ad5664r5", ID_AD5664R5},
 	{}
 };