The AD5758 is a single channel DAC with 16-bit precision which uses the SPI
interface that operates at clock rates up to 50MHz.

The output can be configured as voltage or current and is available on a
single terminal.

Datasheet:
http://www.analog.com/media/en/technical-documentation/data-sheets/ad5758.pdf

Signed-off-by: Stefan Popa <stefan.p...@analog.com>
---
Changes in v2:
        - removed unnecessary parenthesis in AD5758_REG_WRITE macro.
        - added missing documentation fields of ad5758_state struct.
        - changed the type of pwr_down attribute to bool.
        - changed ad5758_dc_dc_ilimt[] to ad5758_dc_dc_ilim[].
        - ad5758_spi_reg_write() now returns spi_write(st->spi,
          &st->data[0].d32, sizeof(st->data[0].d32));
        - removed unnecessary new line in ad5758_calib_mem_refresh().
        - changed the type of the mode parameter in
          ad5758_set_dc_dc_conv_mode() from unsigned int to enum
          ad5758_dc_dc_mode.
        - removed unnecessary parenthesis in ad5758_slew_rate_config().
        - changed the type of the enable parameter in
          ad5758_fault_prot_switch_en() from unsigned char to bool.
        - the same as above, but for ad5758_internal_buffers_en().
        - added a missing mutex_unlock() in ad5758_reg_access().
        - moved the mutex_unlock() in ad5758_read_raw() and removed the
          unreachable return.
        - returned directly where it was possible in ad5758_write_raw().
        - removed the channel, scan_type and scan_index fields.
        - in ad5758_parse_dt(), added missing "\n", and specified what the
          default mode actually is.
        - returned directly at the end of ad5758_init().
        - in ad5758_probe() used device managed for registering the device
          and returned directly without the error message.

 MAINTAINERS              |   7 +
 drivers/iio/dac/Kconfig  |  10 +
 drivers/iio/dac/Makefile |   1 +
 drivers/iio/dac/ad5758.c | 805 +++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 823 insertions(+)
 create mode 100644 drivers/iio/dac/ad5758.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 4b65225..1993779 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -802,6 +802,13 @@ S: Supported
 F:     drivers/iio/dac/ad5686*
 F:     drivers/iio/dac/ad5696*
 
+ANALOG DEVICES INC AD5758 DRIVER
+M:     Stefan Popa <stefan.p...@analog.com>
+L:     linux-...@vger.kernel.org
+W:     http://ez.analog.com/community/linux-device-drivers
+S:     Supported
+F:     drivers/iio/dac/ad5758.c
+
 ANALOG DEVICES INC AD9389B DRIVER
 M:     Hans Verkuil <hans.verk...@cisco.com>
 L:     linux-me...@vger.kernel.org
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 06e90de..80beb64 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -167,6 +167,16 @@ config AD5755
          To compile this driver as a module, choose M here: the
          module will be called ad5755.
 
+config AD5758
+       tristate "Analog Devices AD5758 DAC driver"
+       depends on SPI_MASTER
+       help
+         Say yes here to build support for Analog Devices AD5758 single channel
+         Digital to Analog Converter.
+
+         To compile this driver as a module, choose M here: the
+         module will be called ad5758.
+
 config AD5761
        tristate "Analog Devices AD5761/61R/21/21R DAC driver"
        depends on SPI_MASTER
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index 57aa230..e859f2d 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -16,6 +16,7 @@ obj-$(CONFIG_AD5592R_BASE) += ad5592r-base.o
 obj-$(CONFIG_AD5592R) += ad5592r.o
 obj-$(CONFIG_AD5593R) += ad5593r.o
 obj-$(CONFIG_AD5755) += ad5755.o
+obj-$(CONFIG_AD5758) += ad5758.o
 obj-$(CONFIG_AD5761) += ad5761.o
 obj-$(CONFIG_AD5764) += ad5764.o
 obj-$(CONFIG_AD5791) += ad5791.o
diff --git a/drivers/iio/dac/ad5758.c b/drivers/iio/dac/ad5758.c
new file mode 100644
index 0000000..3008a3a
--- /dev/null
+++ b/drivers/iio/dac/ad5758.c
@@ -0,0 +1,805 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * AD5758 Digital to analog converters driver
+ *
+ * Copyright 2018 Analog Devices Inc.
+ */
+
+#include <linux/fs.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/sysfs.h>
+#include <linux/spi/spi.h>
+#include <linux/delay.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/property.h>
+
+/* AD5758 registers definition */
+#define AD5758_NOP                                     0x00
+#define AD5758_DAC_INPUT                               0x01
+#define AD5758_DAC_OUTPUT                              0x02
+#define AD5758_CLEAR_CODE                              0x03
+#define AD5758_USER_GAIN                               0x04
+#define AD5758_USER_OFFSET                             0x05
+#define AD5758_DAC_CONFIG                              0x06
+#define AD5758_SW_LDAC                                 0x07
+#define AD5758_KEY                                     0x08
+#define AD5758_GP_CONFIG1                              0x09
+#define AD5758_GP_CONFIG2                              0x0A
+#define AD5758_DCDC_CONFIG1                            0x0B
+#define AD5758_DCDC_CONFIG2                            0x0C
+#define AD5758_WDT_CONFIG                              0x0F
+#define AD5758_DIGITAL_DIAG_CONFIG                     0x10
+#define AD5758_ADC_CONFIG                              0x11
+#define AD5758_FAULT_PIN_CONFIG                                0x12
+#define AD5758_TWO_STAGE_READBACK_SELECT               0x13
+#define AD5758_DIGITAL_DIAG_RESULTS                    0x14
+#define AD5758_ANALOG_DIAG_RESULTS                     0x15
+#define AD5758_STATUS                                  0x16
+#define AD5758_CHIP_ID                                 0x17
+#define AD5758_FREQ_MONITOR                            0x18
+#define AD5758_DEVICE_ID_0                             0x19
+#define AD5758_DEVICE_ID_1                             0x1A
+#define AD5758_DEVICE_ID_2                             0x1B
+#define AD5758_DEVICE_ID_3                             0x1C
+
+/* AD5758_DAC_CONFIG */
+#define AD5758_DAC_CONFIG_RANGE_MSK                    GENMASK(3, 0)
+#define AD5758_DAC_CONFIG_RANGE_MODE(x)                        (((x) & 0xF) << 
0)
+#define AD5758_DAC_CONFIG_OVRNG_EN_MSK                 BIT(4)
+#define AD5758_DAC_CONFIG_OVRNG_EN_MODE(x)             (((x) & 0x1) << 4)
+#define AD5758_DAC_CONFIG_INT_EN_MSK                   BIT(5)
+#define AD5758_DAC_CONFIG_INT_EN_MODE(x)               (((x) & 0x1) << 5)
+#define AD5758_DAC_CONFIG_OUT_EN_MSK                   BIT(6)
+#define AD5758_DAC_CONFIG_OUT_EN_MODE(x)               (((x) & 0x1) << 6)
+#define AD5758_DAC_CONFIG_RSET_EXT_EN_MSK              BIT(7)
+#define AD5758_DAC_CONFIG_RSET_EXT_EN_MODE(x)          (((x) & 0x1) << 7)
+#define AD5758_DAC_CONFIG_SR_EN_MSK                    BIT(8)
+#define AD5758_DAC_CONFIG_SR_EN_MODE(x)                        (((x) & 0x1) << 
8)
+#define AD5758_DAC_CONFIG_SR_CLOCK_MSK                 GENMASK(12, 9)
+#define AD5758_DAC_CONFIG_SR_CLOCK_MODE(x)             (((x) & 0xF) << 9)
+#define AD5758_DAC_CONFIG_SR_STEP_MSK                  GENMASK(15, 13)
+#define AD5758_DAC_CONFIG_SR_STEP_MODE(x)              (((x) & 0x7) << 13)
+
+/* AD5758_KEY */
+#define AD5758_KEY_CODE_RESET_1                                0x15FA
+#define AD5758_KEY_CODE_RESET_2                                0xAF51
+#define AD5758_KEY_CODE_SINGLE_ADC_CONV                        0x1ADC
+#define AD5758_KEY_CODE_RESET_WDT                      0x0D06
+#define AD5758_KEY_CODE_CALIB_MEM_REFRESH              0xFCBA
+
+/* AD5758_DCDC_CONFIG1 */
+#define AD5758_DCDC_CONFIG1_DCDC_VPROG_MSK             GENMASK(4, 0)
+#define AD5758_DCDC_CONFIG1_DCDC_VPROG_MODE(x)         (((x) & 0x1F) << 0)
+#define AD5758_DCDC_CONFIG1_DCDC_MODE_MSK              GENMASK(6, 5)
+#define AD5758_DCDC_CONFIG1_DCDC_MODE_MODE(x)          (((x) & 0x3) << 5)
+#define AD5758_DCDC_CONFIG1_FAULT_PROT_SW_EN_MSK       BIT(7)
+#define AD5758_DCDC_CONFIG1_FAULT_PROT_SW_EN_MODE(x)   (((x) & 0x1) << 7)
+
+/* AD5758_DCDC_CONFIG2 */
+#define AD5758_DCDC_CONFIG2_ILIMIT_MSK                 GENMASK(3, 1)
+#define AD5758_DCDC_CONFIG2_ILIMIT_MODE(x)             (((x) & 0x7) << 1)
+#define AD5758_DCDC_CONFIG2_ADC_CONTROL_DIAG_MSK       GENMASK(5, 4)
+#define AD5758_DCDC_CONFIG2_ADC_CONTROL_DIAG_MODE(x)   (((x) & 0x3) << 4)
+#define AD5758_DCDC_CONFIG2_VIOUT_PULLDOWN_EN_MSK      BIT(6)
+#define AD5758_DCDC_CONFIG2_VIOUT_PULLDOWN_EN_MODE(x)  (((x) & 0x1) << 6)
+#define AD5758_DCDC_CONFIG2_SHORT_DEGLITCH_MSK         BIT(7)
+#define AD5758_DCDC_CONFIG2_SHORT_DEGLITCH_MODE(x)     (((x) & 0x1) << 7)
+#define AD5758_DCDC_CONFIG2_READ_COMP_DIS_MSK          BIT(10)
+#define AD5758_DCDC_CONFIG2_READ_COMP_DIS_MODE(x)      (((x) & 0x1) << 10)
+#define AD5758_DCDC_CONFIG2_INTR_SAT_3WI_MSK           BIT(11)
+#define AD5758_DCDC_CONFIG2_BUSY_3WI_MSK               BIT(12)
+
+/* AD5758_DIGITAL_DIAG_RESULTS */
+#define AD5758_DIG_DIAG_RES_CAL_MEM_UNREFRESHED_MSK    BIT(15)
+
+#define AD5758_REG_WRITE(x)    (0x80 | ((x) & 0x1F))
+
+/* x^8 + x^2 + x^1 + x^0 */
+#define AD5758_CRC8_POLY       0x07
+
+/**
+ * struct ad5758_state - driver instance specific data
+ * @spi:       spi_device
+ * @lock:      mutex lock
+ * @dc_dc_mode:        variable which stores the mode of operation
+ * @dc_dc_ilim:        variable which stores the dc-to-dc converter current 
limit
+ * @sr_config: array which stores the slew rate settings
+ * @out_range: variable which stores the output range
+ * @pwr_down:  variable which contains whether a channel is powered down or not
+ * @data:      spi transfer buffers
+ */
+
+struct ad5758_state {
+       struct spi_device *spi;
+       struct mutex lock;
+       unsigned int dc_dc_mode;
+       unsigned int dc_dc_ilim;
+       unsigned int sr_config[3];
+       unsigned int out_range;
+       bool pwr_down;
+
+       /*
+        * DMA (thus cache coherency maintenance) requires the
+        * transfer buffers to live in their own cache lines.
+        */
+
+       union {
+               __be32 d32;
+               u8 d8[4];
+       } data[3] ____cacheline_aligned;
+};
+
+enum ad5758_output_range {
+       AD5758_RANGE_0V_5V,
+       AD5758_RANGE_0V_10V,
+       AD5758_RANGE_PLUSMINUS_5V,
+       AD5758_RANGE_PLUSMINUS_10V,
+       AD5758_RANGE_0mA_20mA = 8,
+       AD5758_RANGE_0mA_24mA,
+       AD5758_RANGE_4mA_24mA,
+       AD5758_RANGE_PLUSMINUS_20mA,
+       AD5758_RANGE_PLUSMINUS_24mA,
+       AD5758_RANGE_MINUS_1mA_PLUS_22mA,
+};
+
+enum ad5758_dc_dc_mode {
+       AD5758_DCDC_MODE_POWER_OFF,
+       AD5758_DCDC_MODE_DPC_CURRENT,
+       AD5758_DCDC_MODE_DPC_VOLTAGE,
+       AD5758_DCDC_MODE_PPC_CURRENT,
+};
+
+struct ad5758_range {
+       int reg;
+       int min;
+       int max;
+};
+
+static const struct ad5758_range ad5758_min_max_table[] = {
+       { AD5758_RANGE_0V_5V, 0, 5000 },
+       { AD5758_RANGE_0V_10V, 0, 10000 },
+       { AD5758_RANGE_PLUSMINUS_5V, -5000, 5000 },
+       { AD5758_RANGE_PLUSMINUS_10V, -10000, 10000 },
+       { AD5758_RANGE_0mA_20mA, 0, 20},
+       { AD5758_RANGE_0mA_24mA, 0, 24 },
+       { AD5758_RANGE_4mA_24mA, 4, 24 },
+       { AD5758_RANGE_PLUSMINUS_20mA, -20, 20 },
+       { AD5758_RANGE_PLUSMINUS_24mA, -24, 24 },
+       { AD5758_RANGE_MINUS_1mA_PLUS_22mA, -1, 22 },
+};
+
+static const int ad5758_slew_rate_clk[16] = {
+       240000, 200000, 150000, 128000, 64000, 32000, 16000, 8000, 4000, 2000,
+       1000, 512, 256, 128, 64, 16
+};
+
+static const int ad5758_slew_rate_step[8] = {
+       4, 12, 64, 120, 256, 500, 1820, 2048
+};
+
+static const int ad5758_dc_dc_ilim[6] = {
+       150, 200, 250, 300, 350, 400
+};
+
+static int ad5758_spi_reg_read(struct ad5758_state *st, unsigned int addr)
+{
+       struct spi_transfer t[] = {
+               {
+                       .tx_buf = &st->data[0].d8[0],
+                       .len = 4,
+                       .cs_change = 1,
+               }, {
+                       .tx_buf = &st->data[1].d8[0],
+                       .rx_buf = &st->data[2].d8[0],
+                       .len = 4,
+               },
+       };
+       int ret;
+
+       st->data[0].d32 = cpu_to_be32(
+               (AD5758_REG_WRITE(AD5758_TWO_STAGE_READBACK_SELECT) << 24) |
+               (addr << 8));
+       st->data[1].d32 = cpu_to_be32(AD5758_REG_WRITE(AD5758_NOP) << 24);
+
+       ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
+       if (ret < 0)
+               return ret;
+
+       return (be32_to_cpu(st->data[2].d32) >> 8) & 0xFFFF;
+}
+
+static int ad5758_spi_reg_write(struct ad5758_state *st,
+                               unsigned int addr,
+                               unsigned int val)
+{
+       st->data[0].d32 = cpu_to_be32((AD5758_REG_WRITE(addr) << 24) |
+                                     ((val & 0xFFFF) << 8));
+
+       return spi_write(st->spi, &st->data[0].d32, sizeof(st->data[0].d32));
+}
+
+static int ad5758_spi_write_mask(struct ad5758_state *st,
+                                unsigned int addr,
+                                unsigned long int mask,
+                                unsigned int val)
+{
+       int regval;
+
+       regval = ad5758_spi_reg_read(st, addr);
+       if (regval < 0)
+               return regval;
+
+       regval &= ~mask;
+       regval |= val;
+
+       return ad5758_spi_reg_write(st, addr, regval);
+}
+
+static int ad5758_get_array_index(const int *array, unsigned int size, int val)
+{
+       int i;
+
+       for (i = 0; i < size; i++) {
+               if (val == array[i])
+                       return i;
+       }
+
+       return -EINVAL;
+}
+
+static int ad5758_wait_for_task_complete(struct ad5758_state *st,
+                                        unsigned int reg,
+                                        unsigned int mask)
+{
+       unsigned int timeout;
+       int ret;
+
+       timeout = 4;
+       do {
+               ret = ad5758_spi_reg_read(st, reg);
+               if (ret < 0)
+                       return ret;
+
+               if (!(ret & mask))
+                       return 0;
+
+               mdelay(1);
+       } while (--timeout);
+
+       dev_err(&st->spi->dev,
+               "Error reading bit 0x%x in 0x%x register\n", mask, reg);
+
+       return -EIO;
+}
+
+static int ad5758_calib_mem_refresh(struct ad5758_state *st)
+{
+       int ret;
+
+       ret = ad5758_spi_reg_write(st, AD5758_KEY,
+                                  AD5758_KEY_CODE_CALIB_MEM_REFRESH);
+       if (ret < 0) {
+               dev_err(&st->spi->dev,
+                       "Failed to initiate a calibration memory refresh\n");
+               return ret;
+       }
+
+       /* Wait to allow time for the internal calibrations to complete */
+       return ad5758_wait_for_task_complete(st, AD5758_DIGITAL_DIAG_RESULTS,
+                               AD5758_DIG_DIAG_RES_CAL_MEM_UNREFRESHED_MSK);
+}
+
+static int ad5758_soft_reset(struct ad5758_state *st)
+{
+       int ret;
+
+       ret = ad5758_spi_reg_write(st, AD5758_KEY, AD5758_KEY_CODE_RESET_1);
+       if (ret < 0)
+               return ret;
+
+       ret = ad5758_spi_reg_write(st, AD5758_KEY, AD5758_KEY_CODE_RESET_2);
+
+       mdelay(1);
+
+       return ret;
+}
+
+static int ad5758_set_dc_dc_conv_mode(struct ad5758_state *st,
+                                     enum ad5758_dc_dc_mode mode)
+{
+       int ret;
+
+       ret = ad5758_spi_write_mask(st, AD5758_DCDC_CONFIG1,
+                                   AD5758_DCDC_CONFIG1_DCDC_MODE_MSK,
+                                   AD5758_DCDC_CONFIG1_DCDC_MODE_MODE(mode));
+       if (ret < 0)
+               return ret;
+
+       /*
+        * Poll the BUSY_3WI bit in the DCDC_CONFIG2 register until it is 0.
+        * This allows the 3-wire interface communication to complete.
+        */
+       ret = ad5758_wait_for_task_complete(st, AD5758_DCDC_CONFIG2,
+                                           AD5758_DCDC_CONFIG2_BUSY_3WI_MSK);
+       if (ret < 0)
+               return ret;
+
+       st->dc_dc_mode = mode;
+
+       return ret;
+}
+
+static int ad5758_set_dc_dc_ilim(struct ad5758_state *st, unsigned int ilim)
+{
+       int ret;
+
+       ret = ad5758_spi_write_mask(st, AD5758_DCDC_CONFIG2,
+                                   AD5758_DCDC_CONFIG2_ILIMIT_MSK,
+                                   AD5758_DCDC_CONFIG2_ILIMIT_MODE(ilim));
+       if (ret < 0)
+               return ret;
+       /*
+        * Poll the BUSY_3WI bit in the DCDC_CONFIG2 register until it is 0.
+        * This allows the 3-wire interface communication to complete.
+        */
+       return ad5758_wait_for_task_complete(st, AD5758_DCDC_CONFIG2,
+                                            AD5758_DCDC_CONFIG2_BUSY_3WI_MSK);
+}
+
+static int ad5758_slew_rate_config(struct ad5758_state *st,
+                                  unsigned int enable,
+                                  unsigned int sr_clk,
+                                  unsigned int sr_step)
+{
+       unsigned int mode;
+       unsigned long int mask;
+       int ret;
+
+       mask = AD5758_DAC_CONFIG_SR_EN_MSK |
+              AD5758_DAC_CONFIG_SR_CLOCK_MSK |
+              AD5758_DAC_CONFIG_SR_STEP_MSK;
+
+       mode = AD5758_DAC_CONFIG_SR_EN_MODE(enable) |
+               AD5758_DAC_CONFIG_SR_CLOCK_MODE(sr_clk) |
+               AD5758_DAC_CONFIG_SR_STEP_MODE(sr_step);
+
+       ret = ad5758_spi_write_mask(st, AD5758_DAC_CONFIG, mask, mode);
+       if (ret < 0)
+               return ret;
+
+       /* Wait to allow time for the internal calibrations to complete */
+       return ad5758_wait_for_task_complete(st, AD5758_DIGITAL_DIAG_RESULTS,
+                               AD5758_DIG_DIAG_RES_CAL_MEM_UNREFRESHED_MSK);
+}
+
+static int ad5758_set_out_range(struct ad5758_state *st, unsigned int range)
+{
+       int ret;
+
+       ret = ad5758_spi_write_mask(st, AD5758_DAC_CONFIG,
+                                   AD5758_DAC_CONFIG_RANGE_MSK,
+                                   AD5758_DAC_CONFIG_RANGE_MODE(
+                                           ad5758_min_max_table[range].reg));
+       if (ret < 0)
+               return ret;
+
+       /* Wait to allow time for the internal calibrations to complete */
+       ret =  ad5758_wait_for_task_complete(st, AD5758_DIGITAL_DIAG_RESULTS,
+                               AD5758_DIG_DIAG_RES_CAL_MEM_UNREFRESHED_MSK);
+       if (ret < 0)
+               return ret;
+
+       st->out_range = range;
+
+       return ret;
+}
+
+static int ad5758_fault_prot_switch_en(struct ad5758_state *st, bool enable)
+{
+       int ret;
+
+       ret = ad5758_spi_write_mask(st, AD5758_DCDC_CONFIG1,
+                       AD5758_DCDC_CONFIG1_FAULT_PROT_SW_EN_MSK,
+                       AD5758_DCDC_CONFIG1_FAULT_PROT_SW_EN_MODE(enable));
+       if (ret < 0)
+               return ret;
+       /*
+        * Poll the BUSY_3WI bit in the DCDC_CONFIG2 register until it is 0.
+        * This allows the 3-wire interface communication to complete.
+        */
+       return ad5758_wait_for_task_complete(st, AD5758_DCDC_CONFIG2,
+                                            AD5758_DCDC_CONFIG2_BUSY_3WI_MSK);
+}
+
+static int ad5758_internal_buffers_en(struct ad5758_state *st, bool enable)
+{
+       int ret;
+
+       ret = ad5758_spi_write_mask(st, AD5758_DAC_CONFIG,
+                                   AD5758_DAC_CONFIG_INT_EN_MSK,
+                                   AD5758_DAC_CONFIG_INT_EN_MODE(enable));
+       if (ret < 0)
+               return ret;
+
+       /* Wait to allow time for the internal calibrations to complete */
+       return ad5758_wait_for_task_complete(st, AD5758_DIGITAL_DIAG_RESULTS,
+                               AD5758_DIG_DIAG_RES_CAL_MEM_UNREFRESHED_MSK);
+}
+
+static int ad5758_reg_access(struct iio_dev *indio_dev,
+                            unsigned int reg,
+                            unsigned int writeval,
+                            unsigned int *readval)
+{
+       struct ad5758_state *st = iio_priv(indio_dev);
+       int ret;
+
+       mutex_lock(&st->lock);
+       if (readval == NULL) {
+               ret =  ad5758_spi_reg_write(st, reg, writeval);
+       } else {
+               ret = ad5758_spi_reg_read(st, reg);
+               if (ret < 0) {
+                       mutex_unlock(&st->lock);
+                       return ret;
+               }
+
+               *readval = ret;
+               ret = 0;
+       }
+       mutex_unlock(&st->lock);
+
+       return ret;
+}
+
+static int ad5758_read_raw(struct iio_dev *indio_dev,
+                          struct iio_chan_spec const *chan,
+                          int *val, int *val2, long info)
+{
+       struct ad5758_state *st = iio_priv(indio_dev);
+       int max, min, ret;
+
+       switch (info) {
+       case IIO_CHAN_INFO_RAW:
+               mutex_lock(&st->lock);
+               ret = ad5758_spi_reg_read(st, AD5758_DAC_INPUT);
+               mutex_unlock(&st->lock);
+               if (ret < 0)
+                       return ret;
+
+               *val = ret;
+               return IIO_VAL_INT;
+       case IIO_CHAN_INFO_SCALE:
+               min = ad5758_min_max_table[st->out_range].min;
+               max = ad5758_min_max_table[st->out_range].max;
+               *val = max - min;
+               *val2 = chan->scan_type.realbits;
+               return IIO_VAL_FRACTIONAL_LOG2;
+       default:
+               return -EINVAL;
+       }
+}
+
+static int ad5758_write_raw(struct iio_dev *indio_dev,
+                           struct iio_chan_spec const *chan,
+                           int val, int val2, long info)
+{
+       struct ad5758_state *st = iio_priv(indio_dev);
+       int ret;
+
+       switch (info) {
+       case IIO_CHAN_INFO_RAW:
+               mutex_lock(&st->lock);
+               ret = ad5758_spi_reg_write(st, AD5758_DAC_INPUT, val);
+               mutex_unlock(&st->lock);
+               return ret;
+       default:
+               return -EINVAL;
+       }
+}
+
+static ssize_t ad5758_read_powerdown(struct iio_dev *indio_dev,
+                                    uintptr_t priv,
+                                    const struct iio_chan_spec *chan,
+                                    char *buf)
+{
+       struct ad5758_state *st = iio_priv(indio_dev);
+
+       return sprintf(buf, "%d\n", st->pwr_down);
+}
+
+static ssize_t ad5758_write_powerdown(struct iio_dev *indio_dev,
+                                     uintptr_t priv,
+                                     struct iio_chan_spec const *chan,
+                                     const char *buf, size_t len)
+{
+       struct ad5758_state *st = iio_priv(indio_dev);
+       bool pwr_down;
+       unsigned int dcdc_config1_mode, dc_dc_mode, dac_config_mode, val;
+       unsigned long int dcdc_config1_msk, dac_config_msk;
+       int ret;
+
+       ret = strtobool(buf, &pwr_down);
+       if (ret)
+               return ret;
+
+       mutex_lock(&st->lock);
+       if (pwr_down) {
+               dc_dc_mode = AD5758_DCDC_MODE_POWER_OFF;
+               val = 0;
+       } else {
+               dc_dc_mode = st->dc_dc_mode;
+               val = 1;
+       }
+
+       dcdc_config1_mode = (AD5758_DCDC_CONFIG1_DCDC_MODE_MODE(dc_dc_mode) |
+                            AD5758_DCDC_CONFIG1_FAULT_PROT_SW_EN_MODE(val));
+       dcdc_config1_msk = (AD5758_DCDC_CONFIG1_DCDC_MODE_MSK |
+                           AD5758_DCDC_CONFIG1_FAULT_PROT_SW_EN_MSK);
+
+       ret = ad5758_spi_write_mask(st, AD5758_DCDC_CONFIG1,
+                                   dcdc_config1_msk,
+                                   dcdc_config1_mode);
+       if (ret < 0)
+               goto err_unlock;
+
+       dac_config_mode = (AD5758_DAC_CONFIG_OUT_EN_MODE(val) |
+                          AD5758_DAC_CONFIG_INT_EN_MODE(val));
+       dac_config_msk =  (AD5758_DAC_CONFIG_OUT_EN_MSK |
+                          AD5758_DAC_CONFIG_INT_EN_MSK);
+
+       ret = ad5758_spi_write_mask(st, AD5758_DAC_CONFIG,
+                                   dac_config_msk,
+                                   dac_config_mode);
+       if (ret < 0)
+               goto err_unlock;
+
+       st->pwr_down = pwr_down;
+
+err_unlock:
+       mutex_unlock(&st->lock);
+
+       return ret ? ret : len;
+}
+
+static const struct iio_info ad5758_info = {
+       .read_raw = ad5758_read_raw,
+       .write_raw = ad5758_write_raw,
+       .debugfs_reg_access = &ad5758_reg_access,
+};
+
+static const struct iio_chan_spec_ext_info ad5758_ext_info[] = {
+       {
+               .name = "powerdown",
+               .read = ad5758_read_powerdown,
+               .write = ad5758_write_powerdown,
+               .shared = IIO_SEPARATE,
+       },
+       { },
+};
+
+static const struct iio_chan_spec ad5758_channels[] = {
+       {
+               .type = IIO_VOLTAGE,
+               .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+               .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+               .indexed = 1,
+               .output = 1,
+               .ext_info = ad5758_ext_info,
+       },
+};
+
+static int ad5758_crc_disable(struct ad5758_state *st)
+{
+       st->data[0].d32 =
+               cpu_to_be32(
+               (AD5758_REG_WRITE(AD5758_DIGITAL_DIAG_CONFIG) << 24) | 0x5C3A);
+
+       return spi_write(st->spi, &st->data[0].d8[0], 4);
+}
+
+static void ad5758_parse_dt(struct ad5758_state *st)
+{
+       unsigned int i, tmp, tmparray[3];
+       int index;
+
+       st->dc_dc_ilim = 150;
+       if (!device_property_read_u32(&st->spi->dev,
+                                     "adi,dc-dc-ilim", &tmp)) {
+               index = ad5758_get_array_index(ad5758_dc_dc_ilim,
+                                       ARRAY_SIZE(ad5758_dc_dc_ilim), tmp);
+               if (index < 0)
+                       dev_warn(&st->spi->dev,
+                                "dc-dc-ilim out of range, using 150mA\n");
+               else
+                       st->dc_dc_ilim = index;
+       } else {
+               dev_dbg(&st->spi->dev,
+                        "Missing \"dc-dc-ilim\" property, using 150mA\n");
+       }
+
+       st->dc_dc_mode = AD5758_DCDC_MODE_DPC_VOLTAGE;
+       if (device_property_read_u32(&st->spi->dev, "adi,dc-dc-mode",
+                                    &st->dc_dc_mode))
+               dev_dbg(&st->spi->dev,
+                       "Missing \"dc-dc-mode\" property, using DPC_VOLTAGE\n");
+
+       /* 0 V to 5 V voltage range */
+       st->out_range = 0;
+       if (!device_property_read_u32(&st->spi->dev, "adi,range", &tmp)) {
+               for (i = 0; i < ARRAY_SIZE(ad5758_min_max_table); i++) {
+                       if (tmp == ad5758_min_max_table[i].reg) {
+                               st->out_range = i;
+                               break;
+                       }
+               }
+
+               if (i == ARRAY_SIZE(ad5758_min_max_table))
+                       dev_warn(&st->spi->dev,
+                                "range invalid, using 0V to 5V\n");
+       } else {
+               dev_dbg(&st->spi->dev,
+                       "Missing \"range\" property, using 0V to 5V\n");
+       }
+
+       st->sr_config[0] = 1;
+       st->sr_config[1] = 16000;
+       st->sr_config[2] = 4;
+       if (!device_property_read_u32_array(&st->spi->dev, "adi,slew",
+                                           tmparray, 3)) {
+               st->sr_config[0] = tmparray[0];
+
+               index = ad5758_get_array_index(ad5758_slew_rate_clk,
+                                              ARRAY_SIZE(ad5758_slew_rate_clk),
+                                              tmparray[1]);
+
+               if (index < 0)
+                       dev_warn(&st->spi->dev,
+                               "slew rate clock out of range, using 16kHz\n");
+               else
+                       st->sr_config[1] = index;
+
+               index = ad5758_get_array_index(ad5758_slew_rate_step,
+                                       ARRAY_SIZE(ad5758_slew_rate_step),
+                                       tmparray[2]);
+
+               if (index < 0)
+                       dev_warn(&st->spi->dev,
+                               "slew rate step out of range, using 4 LSB\n");
+               else
+                       st->sr_config[2] = index;
+       } else {
+               dev_dbg(&st->spi->dev,
+                        "Missing \"slew\" property, using 16kHz and 4 LSB\n");
+       }
+}
+
+static int ad5758_init(struct ad5758_state *st)
+{
+       int regval, ret;
+
+       ad5758_parse_dt(st);
+
+       /* Disable CRC checks */
+       ret = ad5758_crc_disable(st);
+       if (ret < 0)
+               return ret;
+
+       /* Perform a software reset */
+       ret = ad5758_soft_reset(st);
+       if (ret < 0)
+               return ret;
+
+       /* Disable CRC checks */
+       ret = ad5758_crc_disable(st);
+       if (ret < 0)
+               return ret;
+
+       /* Perform a calibration memory refresh */
+       ret = ad5758_calib_mem_refresh(st);
+       if (ret < 0)
+               return ret;
+
+       regval = ad5758_spi_reg_read(st, AD5758_DIGITAL_DIAG_RESULTS);
+       if (regval < 0)
+               return regval;
+
+       /* Clear all the error flags */
+       ret = ad5758_spi_reg_write(st, AD5758_DIGITAL_DIAG_RESULTS, regval);
+       if (ret < 0)
+               return ret;
+
+       /* Set the dc-to-dc current limit */
+       ret = ad5758_set_dc_dc_ilim(st, st->dc_dc_ilim);
+       if (ret < 0)
+               return ret;
+
+       /* Configure the dc-to-dc controller mode */
+       ret = ad5758_set_dc_dc_conv_mode(st, st->dc_dc_mode);
+       if (ret < 0)
+               return ret;
+
+       /* Configure the output range */
+       ret = ad5758_set_out_range(st, st->out_range);
+       if (ret < 0)
+               return ret;
+
+       /* Enable Slew Rate Control, set the slew rate clock and step */
+       ret = ad5758_slew_rate_config(st, st->sr_config[0],
+                                     st->sr_config[1], st->sr_config[2]);
+       if (ret < 0)
+               return ret;
+
+       /* Enable the VIOUT fault protection switch (FPS is closed) */
+       ret = ad5758_fault_prot_switch_en(st, 1);
+       if (ret < 0)
+               return ret;
+
+       /* Power up the DAC and internal (INT) amplifiers */
+       ret = ad5758_internal_buffers_en(st, 1);
+       if (ret < 0)
+               return ret;
+
+       /* Enable VIOUT */
+       return ad5758_spi_write_mask(st, AD5758_DAC_CONFIG,
+                                    AD5758_DAC_CONFIG_OUT_EN_MSK,
+                                    AD5758_DAC_CONFIG_OUT_EN_MODE(1));
+}
+
+static int ad5758_probe(struct spi_device *spi)
+{
+       struct ad5758_state *st;
+       struct iio_dev *indio_dev;
+       int ret;
+
+       indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+       if (!indio_dev)
+               return -ENOMEM;
+
+       st = iio_priv(indio_dev);
+       spi_set_drvdata(spi, indio_dev);
+
+       st->spi = spi;
+
+       indio_dev->dev.parent = &spi->dev;
+       indio_dev->name = spi_get_device_id(spi)->name;
+       indio_dev->info = &ad5758_info;
+       indio_dev->modes = INDIO_DIRECT_MODE;
+       indio_dev->channels = ad5758_channels;
+       indio_dev->num_channels = ARRAY_SIZE(ad5758_channels);
+
+       mutex_init(&st->lock);
+
+       ret = ad5758_init(st);
+       if (ret < 0) {
+               dev_err(&spi->dev, "AD5758 init failed\n");
+               return ret;
+       }
+
+       return devm_iio_device_register(&st->spi->dev, indio_dev);
+}
+
+static const struct spi_device_id ad5758_id[] = {
+       { "ad5758", 0 },
+       {}
+};
+MODULE_DEVICE_TABLE(spi, ad5758_id);
+
+static struct spi_driver ad5758_driver = {
+       .driver = {
+               .name = KBUILD_MODNAME,
+       },
+       .probe = ad5758_probe,
+       .id_table = ad5758_id,
+};
+
+module_spi_driver(ad5758_driver);
+
+MODULE_AUTHOR("Stefan Popa <stefan.p...@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD5758 DAC");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

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