iio:dac: Add ad5755 driver

This patch adds support for the AD5755, AD5755-1, AD5757, AD5735, AD5737 16 and
14 bit quad-channel DACs. The AD5757/AD5737 only have current outputs, but
for the AD5755/AD5757 each of the outputs can be configured to either be a
voltage or a current output. We only allow to configure this at device probe
time since usually this needs to match the external circuitry and should not be
changed on the fly.

A few trivial formatting changes on merge.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

drivers/iio/dac/Kconfig

@@ -77,6 +77,17 @@ config AD5504
 	  To compile this driver as a module, choose M here: the
 	  module will be called ad5504.
 
+config AD5755
+	tristate "Analog Devices AD5755/AD5755-1/AD5757/AD5735/AD5737 DAC driver"
+	depends on SPI_MASTER
+	help
+	  Say yes here to build support for Analog Devices AD5755, AD5755-1,
+	  AD5757, AD5735, AD5737 quad channel Digital to
+	  Analog Converter.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called ad5755.
+
 config AD5764
 	tristate "Analog Devices AD5764/64R/44/44R DAC driver"
 	depends on SPI_MASTER

drivers/iio/dac/Makefile

@@ -9,6 +9,7 @@ obj-$(CONFIG_AD5624R_SPI) += ad5624r_spi.o
 obj-$(CONFIG_AD5064) += ad5064.o
 obj-$(CONFIG_AD5504) += ad5504.o
 obj-$(CONFIG_AD5446) += ad5446.o
+obj-$(CONFIG_AD5755) += ad5755.o
 obj-$(CONFIG_AD5764) += ad5764.o
 obj-$(CONFIG_AD5791) += ad5791.o
 obj-$(CONFIG_AD5686) += ad5686.o

include/linux/platform_data/ad5755.h

+/*
+ * Copyright 2012 Analog Devices Inc.
+ *
+ * Licensed under the GPL-2.
+ */
+#ifndef __LINUX_PLATFORM_DATA_AD5755_H__
+#define __LINUX_PLATFORM_DATA_AD5755_H__
+
+enum ad5755_mode {
+	AD5755_MODE_VOLTAGE_0V_5V		= 0,
+	AD5755_MODE_VOLTAGE_0V_10V		= 1,
+	AD5755_MODE_VOLTAGE_PLUSMINUS_5V	= 2,
+	AD5755_MODE_VOLTAGE_PLUSMINUS_10V	= 3,
+	AD5755_MODE_CURRENT_4mA_20mA		= 4,
+	AD5755_MODE_CURRENT_0mA_20mA		= 5,
+	AD5755_MODE_CURRENT_0mA_24mA		= 6,
+};
+
+enum ad5755_dc_dc_phase {
+	AD5755_DC_DC_PHASE_ALL_SAME_EDGE		= 0,
+	AD5755_DC_DC_PHASE_A_B_SAME_EDGE_C_D_OPP_EDGE	= 1,
+	AD5755_DC_DC_PHASE_A_C_SAME_EDGE_B_D_OPP_EDGE	= 2,
+	AD5755_DC_DC_PHASE_90_DEGREE			= 3,
+};
+
+enum ad5755_dc_dc_freq {
+	AD5755_DC_DC_FREQ_250kHZ = 0,
+	AD5755_DC_DC_FREQ_410kHZ = 1,
+	AD5755_DC_DC_FREQ_650kHZ = 2,
+};
+
+enum ad5755_dc_dc_maxv {
+	AD5755_DC_DC_MAXV_23V	= 0,
+	AD5755_DC_DC_MAXV_24V5	= 1,
+	AD5755_DC_DC_MAXV_27V	= 2,
+	AD5755_DC_DC_MAXV_29V5	= 3,
+};
+
+enum ad5755_slew_rate {
+	AD5755_SLEW_RATE_64k	= 0,
+	AD5755_SLEW_RATE_32k	= 1,
+	AD5755_SLEW_RATE_16k	= 2,
+	AD5755_SLEW_RATE_8k	= 3,
+	AD5755_SLEW_RATE_4k	= 4,
+	AD5755_SLEW_RATE_2k	= 5,
+	AD5755_SLEW_RATE_1k	= 6,
+	AD5755_SLEW_RATE_500	= 7,
+	AD5755_SLEW_RATE_250	= 8,
+	AD5755_SLEW_RATE_125	= 9,
+	AD5755_SLEW_RATE_64	= 10,
+	AD5755_SLEW_RATE_32	= 11,
+	AD5755_SLEW_RATE_16	= 12,
+	AD5755_SLEW_RATE_8	= 13,
+	AD5755_SLEW_RATE_4	= 14,
+	AD5755_SLEW_RATE_0_5	= 15,
+};
+
+enum ad5755_slew_step_size {
+	AD5755_SLEW_STEP_SIZE_1 = 0,
+	AD5755_SLEW_STEP_SIZE_2 = 1,
+	AD5755_SLEW_STEP_SIZE_4 = 2,
+	AD5755_SLEW_STEP_SIZE_8 = 3,
+	AD5755_SLEW_STEP_SIZE_16 = 4,
+	AD5755_SLEW_STEP_SIZE_32 = 5,
+	AD5755_SLEW_STEP_SIZE_64 = 6,
+	AD5755_SLEW_STEP_SIZE_128 = 7,
+	AD5755_SLEW_STEP_SIZE_256 = 8,
+};
+
+/**
+ * struct ad5755_platform_data - AD5755 DAC driver platform data
+ * @ext_dc_dc_compenstation_resistor: Whether an external DC-DC converter
+ * compensation register is used.
+ * @dc_dc_phase: DC-DC converter phase.
+ * @dc_dc_freq: DC-DC converter frequency.
+ * @dc_dc_maxv: DC-DC maximum allowed boost voltage.
+ * @dac.mode: The mode to be used for the DAC output.
+ * @dac.ext_current_sense_resistor: Whether an external current sense resistor
+ * is used.
+ * @dac.enable_voltage_overrange: Whether to enable 20% voltage output overrange.
+ * @dac.slew.enable: Whether to enable digital slew.
+ * @dac.slew.rate: Slew rate of the digital slew.
+ * @dac.slew.step_size: Slew step size of the digital slew.
+ **/
+struct ad5755_platform_data {
+	bool ext_dc_dc_compenstation_resistor;
+	enum ad5755_dc_dc_phase dc_dc_phase;
+	enum ad5755_dc_dc_freq dc_dc_freq;
+	enum ad5755_dc_dc_maxv dc_dc_maxv;
+
+	struct {
+		enum ad5755_mode mode;
+		bool ext_current_sense_resistor;
+		bool enable_voltage_overrange;
+		struct {
+			bool enable;
+			enum ad5755_slew_rate rate;
+			enum ad5755_slew_step_size step_size;
+		} slew;
+	} dac[4];
+};
+
+#endif