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Message-ID: <87174c80-aa05-8db7-18e8-e22479d9c635@gmail.com>
Date: Mon, 10 Jul 2023 22:43:07 +0200
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To: Jonathan Cameron <jic23@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Rob Herring <robh+dt@kernel.org>,
        Andrea Collamati <andrea.collamati@gmail.com>
Cc: linux-iio@vger.kernel.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org
From: Andrea Collamati <andrea.collamati@gmail.com>
Subject: add mcp4728 I2C DAC driver
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From 01b156ca1b27be83f4c74c288dbc0bcad178fe0b Mon Sep 17 00:00:00 2001
From: Andrea Collamati <andrea.collamati@gmail.com>
Date: Mon, 10 Jul 2023 16:20:40 +0200
Subject: [PATCH] iio: add mcp4728 I2C DAC driver

Microchip MCP4728 is a 12-bit quad channel
digital-to-analog converter (DAC) with I2C interface.

This patch adds support for per-channel gain, power state and power down mo=
de control.
Current state could be saved to on-chip EEPROM.
Internal voltage reference and external vdd ref are supported.

---
=C2=A0.../bindings/iio/dac/microchip,mcp4728.yaml=C2=A0=C2=A0 |=C2=A0 42 ++
=C2=A0drivers/iio/dac/Kconfig=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0 |=C2=A0 12 +
=C2=A0drivers/iio/dac/Makefile=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0 |=C2=A0=C2=A0 1 +
=C2=A0drivers/iio/dac/mcp4728.c=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0 | 641 ++++++++++++++++++
=C2=A04 files changed, 696 insertions(+)
=C2=A0create mode 100644 Documentation/devicetree/bindings/iio/dac/microchi=
p,mcp4728.yaml
=C2=A0create mode 100644 drivers/iio/dac/mcp4728.c

diff --git a/Documentation/devicetree/bindings/iio/dac/microchip,mcp4728.ya=
ml b/Documentation/devicetree/bindings/iio/dac/microchip,mcp4728.yaml
new file mode 100644
index 000000000000..68f4e359a921
--- /dev/null
+++ b/Documentation/devicetree/bindings/iio/dac/microchip,mcp4728.yaml
@@ -0,0 +1,42 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/iio/dac/microchip,mcp4728.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip mcp4728
+
+maintainers:
+=C2=A0 - Andrea Collamati <andrea.collamati@gmail.com>
+
+properties:
+=C2=A0 compatible:
+=C2=A0=C2=A0=C2=A0 enum:
+=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 - microchip,mcp4728=C2=A0=C2=A0=C2=A0=C2=A0=
 =C2=A0
+=C2=A0 reg:
+=C2=A0=C2=A0=C2=A0 maxItems: 1
+
+=C2=A0 vdd-supply:
+=C2=A0=C2=A0=C2=A0 description: |
+=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 Provides both power and acts as the referen=
ce supply on the mcp4728
+=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 when Internal Vref is not selected.=C2=A0=
=C2=A0=C2=A0=C2=A0 =C2=A0
+
+required:
+=C2=A0 - compatible
+=C2=A0 - reg
+=C2=A0 - vdd-supply
+
+additionalProperties: false
+
+examples:
+=C2=A0 - |
+=C2=A0=C2=A0=C2=A0 i2c {
+=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 #address-cells =3D <1>;
+=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 #size-cells =3D <0>;
+
+=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 mcp4728_dac@64 {
+=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 compati=
ble =3D "microchip,mcp4728";
+=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 reg =3D=
 <0x60>;
+=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 vdd-sup=
ply =3D <&vdac_vdd>;
+=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 };
+=C2=A0=C2=A0=C2=A0 };
diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index c0bf0d84197f..6c96cd30994a 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -376,6 +376,18 @@ config MCP4725
=C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0 To compile this driver as a module, choose =
M here: the module
=C2=A0=C2=A0=C2=A0=C2=A0 =C2=A0 will be called mcp4725.
=C2=A0
+config MCP4728
+=C2=A0=C2=A0=C2=A0 tristate "MCP4728 DAC driver"
+=C2=A0=C2=A0=C2=A0 depends on I2C
+=C2=A0=C2=A0=C2=A0 help
+=C2=A0=C2=A0=C2=A0 =C2=A0 Say Y here if you want to build a driver for the=
 Microchip
+=C2=A0=C2=A0=C2=A0 =C2=A0 MCP4728 quad channel, 12-bit digital-to-analog c=
onverter (DAC)
+=C2=A0=C2=A0=C2=A0 =C2=A0 with I2C interface.
+
+=C2=A0=C2=A0=C2=A0 =C2=A0 To compile this driver as a module, choose M her=
e: the module
+=C2=A0=C2=A0=C2=A0 =C2=A0 will be called mcp4728.
+
+
=C2=A0config MCP4922
=C2=A0=C2=A0=C2=A0=C2=A0 tristate "MCP4902, MCP4912, MCP4922 DAC driver"
=C2=A0=C2=A0=C2=A0=C2=A0 depends on SPI
diff --git a/drivers/iio/dac/Makefile b/drivers/iio/dac/Makefile
index ec3e42713f00..35ac62a61b05 100644
--- a/drivers/iio/dac/Makefile
+++ b/drivers/iio/dac/Makefile
@@ -40,6 +40,7 @@ obj-$(CONFIG_M62332) +=3D m62332.o
=C2=A0obj-$(CONFIG_MAX517) +=3D max517.o
=C2=A0obj-$(CONFIG_MAX5821) +=3D max5821.o
=C2=A0obj-$(CONFIG_MCP4725) +=3D mcp4725.o
+obj-$(CONFIG_MCP4728) +=3D mcp4728.o
=C2=A0obj-$(CONFIG_MCP4922) +=3D mcp4922.o
=C2=A0obj-$(CONFIG_STM32_DAC_CORE) +=3D stm32-dac-core.o
=C2=A0obj-$(CONFIG_STM32_DAC) +=3D stm32-dac.o
diff --git a/drivers/iio/dac/mcp4728.c b/drivers/iio/dac/mcp4728.c
new file mode 100644
index 000000000000..d304fa8ffa26
--- /dev/null
+++ b/drivers/iio/dac/mcp4728.c
@@ -0,0 +1,641 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Support for Microchip MCP4728
+ *
+ * Copyright (C) 2023 Andrea Collamati <andrea.collamati@gmail.com>
+ *
+ * Based on mcp4725 by Peter Meerwald <pmeerw@pmeerw.net>
+ *
+ * Driver for the Microchip I2C 12-bit digital-to-analog quad channels
+ * converter (DAC).
+ *
+ * (7-bit I2C slave address 0x60, the three LSBs can be configured in
+ * hardware)
+ */
+
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/delay.h>
+#include <linux/regulator/consumer.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+
+#define MCP4728_DRV_NAME "mcp4728"
+
+#define MCP4728_RESOLUTION 12
+#define MCP4728_N_CHANNELS 4
+
+#define MCP4728_CMD_POS 3
+#define MCP4728_CMD_UDAC_POS 0
+#define MCP4728_CMD_CH_SEL_POS 1
+
+#define MCP4728_CMD_VREF_MASK 0x80
+#define MCP4728_CMD_VREF_POS 7
+
+#define MCP4728_CMD_PDMODE_MASK 0x60
+#define MCP4728_CMD_PDMODE_POS 5
+
+#define MCP4728_CMD_GAIN_MASK 0x10
+#define MCP4728_CMD_GAIN_POS 4
+
+#define MCP4728_MW_CMD 0x08 // Multiwrite Command
+#define MCP4728_SW_CMD 0x0A // Sequential Write Command (include eeprom)
+
+#define MCP4728_READ_RESPONSE_LEN (MCP4728_N_CHANNELS * 3 * 2) // Read Mes=
sage
+#define MCP4728_WRITE_EEPROM_LEN \
+=C2=A0=C2=A0=C2=A0 (1 + MCP4728_N_CHANNELS * 2) // Sequential Write
+
+enum vref_mode {
+=C2=A0=C2=A0=C2=A0 MCP4728_VREF_EXTERNAL_VDD =3D 0,
+=C2=A0=C2=A0=C2=A0 MCP4728_VRED_INTERNAL_2048mV =3D 1,
+};
+
+enum gain_mode {
+=C2=A0=C2=A0=C2=A0 MCP4728_GAIN_X1 =3D 0,
+=C2=A0=C2=A0=C2=A0 MCP4728_GAIN_X2 =3D 1,
+};
+
+enum iio_powerdown_mode {
+=C2=A0=C2=A0=C2=A0 MCP4728_IIO_1K,
+=C2=A0=C2=A0=C2=A0 MCP4728_IIO_100K,
+=C2=A0=C2=A0=C2=A0 MCP4728_IIO_500K,
+};
+
+struct mcp4728_channel_data {
+=C2=A0=C2=A0=C2=A0 enum vref_mode ref_mode;
+=C2=A0=C2=A0=C2=A0 enum iio_powerdown_mode pd_mode;
+=C2=A0=C2=A0=C2=A0 enum gain_mode g_mode;
+=C2=A0=C2=A0=C2=A0 u16 dac_value;
+};
+
+struct mcp4728_data {
+=C2=A0=C2=A0=C2=A0 struct i2c_client *client;
+=C2=A0=C2=A0=C2=A0 int id;
+=C2=A0=C2=A0=C2=A0 struct regulator *vdd_reg;
+=C2=A0=C2=A0=C2=A0 bool powerdown;
+=C2=A0=C2=A0=C2=A0 struct mcp4728_channel_data channel_data[MCP4728_N_CHAN=
NELS];
+};
+
+#define MCP4728_CHAN(chan)=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 \
+=C2=A0=C2=A0=C2=A0 {=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 \
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 .type =3D IIO_VOLTAGE, .output =3D 1=
, .indexed =3D 1,=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 \
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 .channel =3D chan, .info_mask_separa=
te =3D BIT(IIO_CHAN_INFO_RAW), \
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 .info_mask_shared_by_type =3D BIT(II=
O_CHAN_INFO_SCALE),=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 \
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 .ext_info =3D mcp4728_ext_info,=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=
=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 \
+=C2=A0=C2=A0=C2=A0 }
+
+static int mcp4728_suspend(struct device *dev);
+static int mcp4728_resume(struct device *dev);
+
+static ssize_t mcp4728_store_eeprom(struct device *dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0=C2=A0=C2=A0 struct device_attribute *attr,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0=C2=A0=C2=A0 const char *buf, size_t len)
+{
+=C2=A0=C2=A0=C2=A0 struct iio_dev *indio_dev =3D dev_to_iio_dev(dev);
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+=C2=A0=C2=A0=C2=A0 u8 outbuf[MCP4728_WRITE_EEPROM_LEN];
+=C2=A0=C2=A0=C2=A0 int tries =3D 20;
+=C2=A0=C2=A0=C2=A0 u8 inbuf[3];
+=C2=A0=C2=A0=C2=A0 bool state;
+=C2=A0=C2=A0=C2=A0 int ret;
+=C2=A0=C2=A0=C2=A0 unsigned int i;
+
+=C2=A0=C2=A0=C2=A0 ret =3D kstrtobool(buf, &state);
+=C2=A0=C2=A0=C2=A0 if (ret < 0)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return ret;
+
+=C2=A0=C2=A0=C2=A0 if (!state)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return 0;
+
+=C2=A0=C2=A0=C2=A0 outbuf[0] =3D MCP4728_SW_CMD << MCP4728_CMD_POS; // Com=
mand ID
+
+=C2=A0=C2=A0=C2=A0 for (i =3D 0; i < MCP4728_N_CHANNELS; i++) {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 struct mcp4728_channel_data *ch =3D =
&(data->channel_data[i]);
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 int offset =3D 1 + i * 2;
+
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 outbuf[offset] =3D ch->ref_mode << M=
CP4728_CMD_VREF_POS;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 if (data->powerdown) {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 u8 mcp4728_pd_mod=
e =3D ch->pd_mode + 1;
+
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 outbuf[1] |=3D mc=
p4728_pd_mode << MCP4728_CMD_PDMODE_POS;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 }
+
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 outbuf[offset] |=3D ch->g_mode << MC=
P4728_CMD_GAIN_POS;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 outbuf[offset] |=3D ch->dac_value >>=
 8;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 outbuf[offset + 1] =3D ch->dac_value=
 & 0xff;
+=C2=A0=C2=A0=C2=A0 }
+
+=C2=A0=C2=A0=C2=A0 ret =3D i2c_master_send(data->client, outbuf, MCP4728_W=
RITE_EEPROM_LEN);
+=C2=A0=C2=A0=C2=A0 if (ret < 0)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return ret;
+=C2=A0=C2=A0=C2=A0 else if (ret !=3D MCP4728_WRITE_EEPROM_LEN)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return -EIO;
+
+=C2=A0=C2=A0=C2=A0 /* wait RDY signal for write complete, takes up to 50ms=
 */
+=C2=A0=C2=A0=C2=A0 while (tries--) {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 msleep(20);
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ret =3D i2c_master_recv(data->client=
, inbuf, 3);
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 if (ret < 0)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return ret;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 else if (ret !=3D 3)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return -EIO;
+
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 if (inbuf[0] & 0x80) // check RDY fl=
ag
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 break;
+=C2=A0=C2=A0=C2=A0 }
+
+=C2=A0=C2=A0=C2=A0 if (tries < 0) {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 dev_err(&data->client->dev, "%s fail=
ed, incomplete\n",
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 __func__);
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return -EIO;
+=C2=A0=C2=A0=C2=A0 }
+=C2=A0=C2=A0=C2=A0 return len;
+}
+
+static IIO_DEVICE_ATTR(store_eeprom, 0200, NULL, mcp4728_store_eeprom, 0);
+
+static struct attribute *mcp4728_attributes[] =3D {
+=C2=A0=C2=A0=C2=A0 &iio_dev_attr_store_eeprom.dev_attr.attr,
+=C2=A0=C2=A0=C2=A0 NULL,
+};
+
+static const struct attribute_group mcp4728_attribute_group =3D {
+=C2=A0=C2=A0=C2=A0 .attrs =3D mcp4728_attributes,
+};
+
+enum chip_id {
+=C2=A0=C2=A0=C2=A0 MCP4728,
+};
+
+static int mcp4728_program_channel_cfg(int channel, struct iio_dev *indio_=
dev)
+{
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+=C2=A0=C2=A0=C2=A0 struct mcp4728_channel_data *ch =3D &(data->channel_dat=
a[channel]);
+=C2=A0=C2=A0=C2=A0 u8 outbuf[3];
+=C2=A0=C2=A0=C2=A0 int ret;
+
+=C2=A0=C2=A0=C2=A0 outbuf[0] =3D MCP4728_MW_CMD << MCP4728_CMD_POS; // Com=
mand ID
+=C2=A0=C2=A0=C2=A0 outbuf[0] |=3D channel << MCP4728_CMD_CH_SEL_POS; // Ch=
annel Selector
+=C2=A0=C2=A0=C2=A0 outbuf[0] |=3D 0; // UDAC =3D 0
+
+=C2=A0=C2=A0=C2=A0 outbuf[1] =3D ch->ref_mode << MCP4728_CMD_VREF_POS;
+=C2=A0=C2=A0=C2=A0 if (data->powerdown) {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 u8 mcp4728_pd_mode =3D ch->pd_mode +=
 1;
+
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 outbuf[1] |=3D mcp4728_pd_mode << MC=
P4728_CMD_PDMODE_POS;
+=C2=A0=C2=A0=C2=A0 }
+
+=C2=A0=C2=A0=C2=A0 outbuf[1] |=3D ch->g_mode << MCP4728_CMD_GAIN_POS;
+
+=C2=A0=C2=A0=C2=A0 outbuf[1] |=3D ch->dac_value >> 8;
+=C2=A0=C2=A0=C2=A0 outbuf[2] =3D ch->dac_value & 0xff;
+
+=C2=A0=C2=A0=C2=A0 ret =3D i2c_master_send(data->client, outbuf, 3);
+=C2=A0=C2=A0=C2=A0 if (ret < 0)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return ret;
+=C2=A0=C2=A0=C2=A0 else if (ret !=3D 3)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return -EIO;
+=C2=A0=C2=A0=C2=A0 else
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return 0;
+}
+
+// powerdown mode
+static const char *const mcp4728_powerdown_modes[] =3D {
+=C2=A0=C2=A0=C2=A0 "1kohm_to_gnd",
+=C2=A0=C2=A0=C2=A0 "100kohm_to_gnd",
+=C2=A0=C2=A0=C2=A0 "500kohm_to_gnd"
+};
+
+static int mcp4728_get_powerdown_mode(struct iio_dev *indio_dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 const struct iio_chan_spec *chan)
+{
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+
+=C2=A0=C2=A0=C2=A0 return data->channel_data[chan->channel].pd_mode;
+}
+
+static int mcp4728_set_powerdown_mode(struct iio_dev *indio_dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 const struct iio_chan_spec *chan,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 unsigned int mode)
+{
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+
+=C2=A0=C2=A0=C2=A0 data->channel_data[chan->channel].pd_mode =3D mode;
+
+=C2=A0=C2=A0=C2=A0 return 0;
+}
+
+static ssize_t mcp4728_read_powerdown(struct iio_dev *indio_dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 uintptr_t private,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 const struct iio_chan_spec *chan,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 char *buf)
+{
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+
+=C2=A0=C2=A0=C2=A0 return sysfs_emit(buf, "%d\n", data->powerdown);
+}
+
+static ssize_t mcp4728_write_powerdown(struct iio_dev *indio_dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 uintptr_t private,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 const struct iio_chan_spec *chan,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 const char *buf, size_t len)
+{
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+=C2=A0=C2=A0=C2=A0 bool state;
+=C2=A0=C2=A0=C2=A0 int ret;
+
+=C2=A0=C2=A0=C2=A0 ret =3D kstrtobool(buf, &state);
+=C2=A0=C2=A0=C2=A0 if (ret)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return ret;
+
+=C2=A0=C2=A0=C2=A0 if (state)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ret =3D mcp4728_suspend(&data->clien=
t->dev);
+=C2=A0=C2=A0=C2=A0 else
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ret =3D mcp4728_resume(&data->client=
->dev);
+=C2=A0=C2=A0=C2=A0 if (ret < 0)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return ret;
+
+=C2=A0=C2=A0=C2=A0 return len;
+}
+
+static const struct iio_enum mcp4728_powerdown_mode_enum =3D {
+=C2=A0=C2=A0=C2=A0 .items =3D mcp4728_powerdown_modes,
+=C2=A0=C2=A0=C2=A0 .num_items =3D ARRAY_SIZE(mcp4728_powerdown_modes),
+=C2=A0=C2=A0=C2=A0 .get =3D mcp4728_get_powerdown_mode,
+=C2=A0=C2=A0=C2=A0 .set =3D mcp4728_set_powerdown_mode,
+};
+
+// vref mode
+static const char *const mcp4728_vref_modes[] =3D {
+=C2=A0=C2=A0=C2=A0 "vdd_ext",
+=C2=A0=C2=A0=C2=A0 "internal",
+};
+
+static int mcp4728_get_vref_mode(struct iio_dev *indio_dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0const struct iio_chan_spec *chan)
+{
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+
+=C2=A0=C2=A0=C2=A0 return data->channel_data[chan->channel].ref_mode;
+}
+
+static int mcp4728_set_vref_mode(struct iio_dev *indio_dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0const struct iio_chan_spec *chan,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0unsigned int mode)
+{
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+=C2=A0=C2=A0=C2=A0 int ret;
+
+=C2=A0=C2=A0=C2=A0 data->channel_data[chan->channel].ref_mode =3D mode;
+
+=C2=A0=C2=A0=C2=A0 if (mode =3D=3D MCP4728_VREF_EXTERNAL_VDD &&
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 data->channel_data[chan->channel].g_=
mode =3D=3D MCP4728_GAIN_X2) {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 dev_warn(
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 &data->client->de=
v,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 "CH%d: Gain x2 no=
t effective when vref is vdd, force to x1",
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 chan->channel);
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 data->channel_data[chan->channel].g_=
mode =3D MCP4728_GAIN_X1;
+=C2=A0=C2=A0=C2=A0 }
+
+=C2=A0=C2=A0=C2=A0 ret =3D mcp4728_program_channel_cfg(chan->channel, indi=
o_dev);
+
+=C2=A0=C2=A0=C2=A0 return ret;
+}
+static const struct iio_enum mcp4728_vref_mode_enum =3D {
+=C2=A0=C2=A0=C2=A0 .items =3D mcp4728_vref_modes,
+=C2=A0=C2=A0=C2=A0 .num_items =3D ARRAY_SIZE(mcp4728_vref_modes),
+=C2=A0=C2=A0=C2=A0 .get =3D mcp4728_get_vref_mode,
+=C2=A0=C2=A0=C2=A0 .set =3D mcp4728_set_vref_mode,
+};
+
+// gain
+static const char *const mcp4728_gain_modes[] =3D {
+=C2=A0=C2=A0=C2=A0 "x1",
+=C2=A0=C2=A0=C2=A0 "x2",
+};
+
+static int mcp4728_get_gain_mode(struct iio_dev *indio_dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0const struct iio_chan_spec *chan)
+{
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+
+=C2=A0=C2=A0=C2=A0 return data->channel_data[chan->channel].g_mode;
+}
+
+static int mcp4728_set_gain_mode(struct iio_dev *indio_dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0const struct iio_chan_spec *chan,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0unsigned int mode)
+{
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+=C2=A0=C2=A0=C2=A0 int ret;
+
+=C2=A0=C2=A0=C2=A0 if (mode =3D=3D MCP4728_GAIN_X2 &&
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 data->channel_data[chan->channel].re=
f_mode =3D=3D
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 MCP4728_VREF_EXTE=
RNAL_VDD) {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 dev_err(&data->client->dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 "CH%d: Gain x2 no=
t effective when vref is vdd",
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 chan->channel);
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return -EINVAL;
+=C2=A0=C2=A0=C2=A0 }
+
+=C2=A0=C2=A0=C2=A0 data->channel_data[chan->channel].g_mode =3D mode;
+
+=C2=A0=C2=A0=C2=A0 ret =3D mcp4728_program_channel_cfg(chan->channel, indi=
o_dev);
+
+=C2=A0=C2=A0=C2=A0 return ret;
+}
+
+static const struct iio_enum mcp4728_gain_mode_enum =3D {
+=C2=A0=C2=A0=C2=A0 .items =3D mcp4728_gain_modes,
+=C2=A0=C2=A0=C2=A0 .num_items =3D ARRAY_SIZE(mcp4728_gain_modes),
+=C2=A0=C2=A0=C2=A0 .get =3D mcp4728_get_gain_mode,
+=C2=A0=C2=A0=C2=A0 .set =3D mcp4728_set_gain_mode,
+};
+
+static const struct iio_chan_spec_ext_info mcp4728_ext_info[] =3D {
+=C2=A0=C2=A0=C2=A0 {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 .name =3D "powerdown",
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 .read =3D mcp4728_read_powerdown,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 .write =3D mcp4728_write_powerdown,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 .shared =3D IIO_SEPARATE,
+=C2=A0=C2=A0=C2=A0 },
+=C2=A0=C2=A0=C2=A0 IIO_ENUM("powerdown_mode", IIO_SEPARATE, &mcp4728_power=
down_mode_enum),
+=C2=A0=C2=A0=C2=A0 IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0 &mcp=
4728_powerdown_mode_enum),
+=C2=A0=C2=A0=C2=A0 IIO_ENUM("vref_mode", IIO_SEPARATE, &mcp4728_vref_mode_=
enum),
+=C2=A0=C2=A0=C2=A0 IIO_ENUM_AVAILABLE("vref_mode", IIO_SHARED_BY_TYPE,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0 &mcp=
4728_vref_mode_enum),
+=C2=A0=C2=A0=C2=A0 IIO_ENUM("gain_mode", IIO_SEPARATE, &mcp4728_gain_mode_=
enum),
+=C2=A0=C2=A0=C2=A0 IIO_ENUM_AVAILABLE("gain_mode", IIO_SHARED_BY_TYPE,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0 &mcp=
4728_gain_mode_enum),
+=C2=A0=C2=A0=C2=A0 {},
+};
+
+static const struct iio_chan_spec mcp4728_channels[MCP4728_N_CHANNELS] =3D=
 {
+=C2=A0=C2=A0=C2=A0 MCP4728_CHAN(0),
+=C2=A0=C2=A0=C2=A0 MCP4728_CHAN(1),
+=C2=A0=C2=A0=C2=A0 MCP4728_CHAN(2),
+=C2=A0=C2=A0=C2=A0 MCP4728_CHAN(3),
+};
+
+static int mcp4728_full_scale_mV(u32 *full_scale_mV, int channel,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0struct mcp4728_data *data)
+{
+=C2=A0=C2=A0=C2=A0 int ret;
+
+=C2=A0=C2=A0=C2=A0 if (data->channel_data[channel].ref_mode =3D=3D MCP4728=
_VREF_EXTERNAL_VDD)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ret =3D regulator_get_voltage(data->=
vdd_reg);
+=C2=A0=C2=A0=C2=A0 else
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ret =3D 2048000;
+
+=C2=A0=C2=A0=C2=A0 if (ret < 0)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return ret;
+
+=C2=A0=C2=A0=C2=A0 if (ret =3D=3D 0)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return -EINVAL;
+
+=C2=A0=C2=A0=C2=A0 *full_scale_mV =3D ret / 1000;
+=C2=A0=C2=A0=C2=A0 return 0;
+}
+
+static u32 mcp4728_raw_to_mV(u32 raw, int channel, struct mcp4728_data *da=
ta)
+{
+=C2=A0=C2=A0=C2=A0 int ret;
+=C2=A0=C2=A0=C2=A0 u32 full_scale_mV;
+
+=C2=A0=C2=A0=C2=A0 ret =3D mcp4728_full_scale_mV(&full_scale_mV, channel, =
data);
+=C2=A0=C2=A0=C2=A0 if (ret)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return ret;
+
+=C2=A0=C2=A0=C2=A0 return (((raw + 1) * full_scale_mV) >> MCP4728_RESOLUTI=
ON);
+}
+
+static int mcp4728_read_raw(struct iio_dev *indio_dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 struct iio_chan_spec const *chan, int *val,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 int *val2, long mask)
+{
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+=C2=A0=C2=A0=C2=A0 int ret;
+
+=C2=A0=C2=A0=C2=A0 switch (mask) {
+=C2=A0=C2=A0=C2=A0 case IIO_CHAN_INFO_RAW:
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 *val =3D data->channel_data[chan->ch=
annel].dac_value;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return IIO_VAL_INT;
+=C2=A0=C2=A0=C2=A0 case IIO_CHAN_INFO_SCALE:
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 if (data->channel_data[chan->channel=
].ref_mode =3D=3D
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 MCP4728_VREF_EXTE=
RNAL_VDD)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ret =3D regulator=
_get_voltage(data->vdd_reg);
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 else
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ret =3D 2048000;
+
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 if (ret < 0)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return ret;
+
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 *val =3D ret / 1000;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 *val2 =3D MCP4728_RESOLUTION;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return IIO_VAL_FRACTIONAL_LOG2;
+=C2=A0=C2=A0=C2=A0 }
+=C2=A0=C2=A0=C2=A0 return -EINVAL;
+}
+
+static int mcp4728_write_raw(struct iio_dev *indio_dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0=C2=A0 struct iio_chan_spec const *chan, int val,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0=C2=A0 int val2, long mask)
+{
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+=C2=A0=C2=A0=C2=A0 int ret;
+
+=C2=A0=C2=A0=C2=A0 switch (mask) {
+=C2=A0=C2=A0=C2=A0 case IIO_CHAN_INFO_RAW:
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 if (val < 0 || val > GENMASK(MCP4728=
_RESOLUTION - 1, 0))
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return -EINVAL;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 data->channel_data[chan->channel].da=
c_value =3D val;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ret =3D mcp4728_program_channel_cfg(=
chan->channel, indio_dev);
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 break;
+=C2=A0=C2=A0=C2=A0 default:
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ret =3D -EINVAL;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 break;
+=C2=A0=C2=A0=C2=A0 }
+
+=C2=A0=C2=A0=C2=A0 return ret;
+}
+
+static const struct iio_info mcp4728_info =3D {
+=C2=A0=C2=A0=C2=A0 .read_raw =3D mcp4728_read_raw,
+=C2=A0=C2=A0=C2=A0 .write_raw =3D mcp4728_write_raw,
+=C2=A0=C2=A0=C2=A0 .attrs =3D &mcp4728_attribute_group,
+};
+
+static int mcp4728_suspend(struct device *dev)
+{
+=C2=A0=C2=A0=C2=A0 struct iio_dev *indio_dev =3D i2c_get_clientdata(to_i2c=
_client(dev));
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+=C2=A0=C2=A0=C2=A0 int err =3D 0;
+=C2=A0=C2=A0=C2=A0 unsigned int i;
+
+=C2=A0=C2=A0=C2=A0 data->powerdown =3D true;
+
+=C2=A0=C2=A0=C2=A0 for (i =3D 0; i < MCP4728_N_CHANNELS; i++) {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 int ret =3D mcp4728_program_channel_=
cfg(i, indio_dev);
+
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 if (ret)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 err =3D ret; //sa=
ve last error
+=C2=A0=C2=A0=C2=A0 }
+=C2=A0=C2=A0=C2=A0 return err;
+}
+
+static int mcp4728_resume(struct device *dev)
+{
+=C2=A0=C2=A0=C2=A0 struct iio_dev *indio_dev =3D i2c_get_clientdata(to_i2c=
_client(dev));
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+=C2=A0=C2=A0=C2=A0 int err =3D 0;
+=C2=A0=C2=A0=C2=A0 unsigned int i;
+
+=C2=A0=C2=A0=C2=A0 data->powerdown =3D false;
+
+=C2=A0=C2=A0=C2=A0 for (i =3D 0; i < MCP4728_N_CHANNELS; i++) {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 int ret =3D mcp4728_program_channel_=
cfg(i, indio_dev);
+
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 if (ret)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 err =3D ret; //sa=
ve last error
+=C2=A0=C2=A0=C2=A0 }
+=C2=A0=C2=A0=C2=A0 return err;
+}
+static DEFINE_SIMPLE_DEV_PM_OPS(mcp4728_pm_ops, mcp4728_suspend,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 mcp4728_resume);
+
+static int mcp4728_init_channels_data(struct mcp4728_data *data)
+{
+=C2=A0=C2=A0=C2=A0 u8 inbuf[MCP4728_READ_RESPONSE_LEN];
+=C2=A0=C2=A0=C2=A0 int ret;
+=C2=A0=C2=A0=C2=A0 unsigned int i;
+
+=C2=A0=C2=A0=C2=A0 ret =3D i2c_master_recv(data->client, inbuf, MCP4728_RE=
AD_RESPONSE_LEN);
+=C2=A0=C2=A0=C2=A0 if (ret < 0) {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 dev_err(&data->client->dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 "failed to read m=
cp4728 conf. Err=3D%d\n", ret);
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return ret;
+=C2=A0=C2=A0=C2=A0 } else if (ret !=3D MCP4728_READ_RESPONSE_LEN) {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 dev_err(&data->client->dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 "failed to read m=
cp4728 conf. Wrong Response Len ret=3D%d\n",
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ret);
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return -EIO;
+=C2=A0=C2=A0=C2=A0 }
+
+=C2=A0=C2=A0=C2=A0 for (i =3D 0; i < MCP4728_N_CHANNELS; i++) {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 struct mcp4728_channel_data *ch =3D =
&(data->channel_data[i]);
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 u8 r2 =3D inbuf[i * 6 + 1];
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 u8 r3 =3D inbuf[i * 6 + 2];
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 u32 dac_mv;
+
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ch->dac_value =3D (r2 & 0x0F) << 8 |=
 r3;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ch->ref_mode =3D (r2 & MCP4728_CMD_V=
REF_MASK) >>
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0=C2=A0 MCP4728_CMD_VREF_POS;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ch->pd_mode =3D (r2 & MCP4728_CMD_PD=
MODE_MASK) >>
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0=C2=A0=C2=A0 MCP4728_CMD_PDMODE_POS;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ch->g_mode =3D (r2 & MCP4728_CMD_GAI=
N_MASK) >>
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0=C2=A0 MCP4728_CMD_GAIN_POS;
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 if (ch->g_mode =3D=3D MCP4728_GAIN_X=
2 &&
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 ch->ref_mode =3D=
=3D MCP4728_VREF_EXTERNAL_VDD)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 dev_warn(&data->c=
lient->dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0"CH%d: Gain x2 not effective when vref is vdd",
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 =C2=A0i);
+
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 dac_mv =3D mcp4728_raw_to_mV(ch->dac=
_value, i, data);
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 dev_info(&data->client->dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0"CH%d: Volt=
age=3D%dmV VRef=3D%d PowerDown=3D%d Gain=3D%d\n", i,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0dac_mv, ch-=
>ref_mode, ch->pd_mode, ch->g_mode);
+=C2=A0=C2=A0=C2=A0 }
+
+=C2=A0=C2=A0=C2=A0 return 0;
+}
+
+static int mcp4728_probe(struct i2c_client *client,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0const struc=
t i2c_device_id *id)
+{
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data;
+=C2=A0=C2=A0=C2=A0 struct iio_dev *indio_dev;
+=C2=A0=C2=A0=C2=A0 int err;
+
+=C2=A0=C2=A0=C2=A0 indio_dev =3D devm_iio_device_alloc(&client->dev, sizeo=
f(*data));
+=C2=A0=C2=A0=C2=A0 if (indio_dev =3D=3D NULL)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return -ENOMEM;
+=C2=A0=C2=A0=C2=A0 data =3D iio_priv(indio_dev);
+=C2=A0=C2=A0=C2=A0 i2c_set_clientdata(client, indio_dev);
+=C2=A0=C2=A0=C2=A0 data->client =3D client;
+=C2=A0=C2=A0=C2=A0 if (dev_fwnode(&client->dev))
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 data->id =3D (uintptr_t)device_get_m=
atch_data(&client->dev);
+=C2=A0=C2=A0=C2=A0 else
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 data->id =3D id->driver_data;
+
+=C2=A0=C2=A0=C2=A0 data->vdd_reg =3D devm_regulator_get(&client->dev, "vdd=
");
+=C2=A0=C2=A0=C2=A0 if (IS_ERR(data->vdd_reg))
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 return PTR_ERR(data->vdd_reg);
+
+=C2=A0=C2=A0=C2=A0 err =3D regulator_enable(data->vdd_reg);
+=C2=A0=C2=A0=C2=A0 if (err)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 goto err_disable_vdd_reg;
+
+=C2=A0=C2=A0=C2=A0 err =3D mcp4728_init_channels_data(data);
+=C2=A0=C2=A0=C2=A0 if (err) {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 dev_err(&client->dev,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 "failed to read m=
cp4728 current configuration\n");
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 goto err_disable_vdd_reg;
+=C2=A0=C2=A0=C2=A0 }
+
+=C2=A0=C2=A0=C2=A0 indio_dev->name =3D id->name;
+=C2=A0=C2=A0=C2=A0 indio_dev->info =3D &mcp4728_info;
+=C2=A0=C2=A0=C2=A0 indio_dev->channels =3D mcp4728_channels;
+=C2=A0=C2=A0=C2=A0 indio_dev->num_channels =3D MCP4728_N_CHANNELS;
+=C2=A0=C2=A0=C2=A0 indio_dev->modes =3D INDIO_DIRECT_MODE;
+
+=C2=A0=C2=A0=C2=A0 err =3D iio_device_register(indio_dev);
+=C2=A0=C2=A0=C2=A0 if (err)
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 goto err_disable_vdd_reg;
+
+=C2=A0=C2=A0=C2=A0 return 0;
+
+err_disable_vdd_reg:
+=C2=A0=C2=A0=C2=A0 regulator_disable(data->vdd_reg);
+
+=C2=A0=C2=A0=C2=A0 return err;
+}
+
+static int mcp4728_remove(struct i2c_client *client)
+{
+=C2=A0=C2=A0=C2=A0 struct iio_dev *indio_dev =3D i2c_get_clientdata(client=
);
+=C2=A0=C2=A0=C2=A0 struct mcp4728_data *data =3D iio_priv(indio_dev);
+
+=C2=A0=C2=A0=C2=A0 iio_device_unregister(indio_dev);
+=C2=A0=C2=A0=C2=A0 regulator_disable(data->vdd_reg);
+=C2=A0=C2=A0=C2=A0 return 0;
+}
+
+static const struct i2c_device_id mcp4728_id[] =3D { { "mcp4728", MCP4728 =
}, {} };
+MODULE_DEVICE_TABLE(i2c, mcp4728_id);
+
+static const struct of_device_id mcp4728_of_match[] =3D {
+=C2=A0=C2=A0=C2=A0 { .compatible =3D "microchip,mcp4728", .data =3D (void =
*)MCP4728 },
+=C2=A0=C2=A0=C2=A0 {}
+};
+MODULE_DEVICE_TABLE(of, mcp4728_of_match);
+
+static struct i2c_driver mcp4728_driver =3D {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 .driver =3D {
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 .name =3D MCP4728_DRV_NAME,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 .of_match_table =3D mcp4728_of_match,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=
=A0 .pm =3D pm_sleep_ptr(&mcp4728_pm_ops),
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 },
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 .probe =3D mcp4728_probe,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 .remove =3D mcp4728_remove,
+=C2=A0=C2=A0=C2=A0 =C2=A0=C2=A0=C2=A0 .id_table =3D mcp4728_id,
+};
+module_i2c_driver(mcp4728_driver);
+
+MODULE_AUTHOR("Andrea Collamati <andrea.collamati@gmail.com>");
+MODULE_DESCRIPTION("MCP4728 12-bit DAC");
+MODULE_LICENSE("GPL");
--=20
2.17.1