iio:dac:ad5686: Refactor the driver
authorStefan Popa <stefan.popa@analog.com>
Wed, 11 Apr 2018 11:53:17 +0000 (14:53 +0300)
committerJonathan Cameron <Jonathan.Cameron@huawei.com>
Sun, 15 Apr 2018 18:36:32 +0000 (19:36 +0100)
In this patch restructures the existing ad5686 driver by adding a module
for SPI and a header file, while the baseline module deals with the
chip-logic.

This is a necessary step, as this driver should support in the future
similar devices which differ only in the type of interface used (I2C
instead of SPI).

Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
MAINTAINERS
drivers/iio/dac/Kconfig
drivers/iio/dac/Makefile
drivers/iio/dac/ad5686-spi.c [new file with mode: 0644]
drivers/iio/dac/ad5686.c
drivers/iio/dac/ad5686.h [new file with mode: 0644]

index 473ac00..637e62d 100644 (file)
@@ -791,6 +791,13 @@ M: Michael Hanselmann <linux-kernel@hansmi.ch>
 S:     Supported
 F:     drivers/macintosh/ams/
 
+ANALOG DEVICES INC AD5686 DRIVER
+M:     Stefan Popa <stefan.popa@analog.com>
+L:     linux-pm@vger.kernel.org
+W:     http://ez.analog.com/community/linux-device-drivers
+S:     Supported
+F:     drivers/iio/dac/ad5686*
+
 ANALOG DEVICES INC AD9389B DRIVER
 M:     Hans Verkuil <hans.verkuil@cisco.com>
 L:     linux-media@vger.kernel.org
index 965d5c0..7a81f1e 100644 (file)
@@ -131,16 +131,21 @@ config LTC2632
          module will be called ltc2632.
 
 config AD5686
-       tristate "Analog Devices AD5686R/AD5685R/AD5684R DAC SPI driver"
+       tristate
+
+config AD5686_SPI
+       tristate "Analog Devices AD5686 and similar multi-channel DACs (SPI)"
        depends on SPI
+       select AD5686
        help
-         Say yes here to build support for Analog Devices AD5686R, AD5685R,
-         AD5684R, AD5791 Voltage Output Digital to
-         Analog Converter.
+         Say yes here to build support for Analog Devices AD5672R, AD5676,
+         AD5676R, AD5684, AD5684R, AD5684R, AD5685R, AD5686, AD5686R.
+         Voltage Output Digital to Analog Converter.
 
          To compile this driver as a module, choose M here: the
          module will be called ad5686.
 
+
 config AD5755
        tristate "Analog Devices AD5755/AD5755-1/AD5757/AD5735/AD5737 DAC driver"
        depends on SPI_MASTER
index 81e710e..07db92e 100644 (file)
@@ -20,6 +20,7 @@ obj-$(CONFIG_AD5761) += ad5761.o
 obj-$(CONFIG_AD5764) += ad5764.o
 obj-$(CONFIG_AD5791) += ad5791.o
 obj-$(CONFIG_AD5686) += ad5686.o
+obj-$(CONFIG_AD5686_SPI) += ad5686-spi.o
 obj-$(CONFIG_AD7303) += ad7303.o
 obj-$(CONFIG_AD8801) += ad8801.o
 obj-$(CONFIG_CIO_DAC) += cio-dac.o
diff --git a/drivers/iio/dac/ad5686-spi.c b/drivers/iio/dac/ad5686-spi.c
new file mode 100644 (file)
index 0000000..6bb09e9
--- /dev/null
@@ -0,0 +1,93 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * AD5672R, AD5676, AD5676R, AD5684, AD5684R, AD5684R, AD5685R, AD5686, AD5686R
+ * Digital to analog converters driver
+ *
+ * Copyright 2018 Analog Devices Inc.
+ */
+
+#include "ad5686.h"
+
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+
+static int ad5686_spi_write(struct ad5686_state *st,
+                           u8 cmd, u8 addr, u16 val)
+{
+       struct spi_device *spi = to_spi_device(st->dev);
+
+       st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
+                                     AD5686_ADDR(addr) |
+                                     val);
+
+       return spi_write(spi, &st->data[0].d8[1], 3);
+}
+
+static int ad5686_spi_read(struct ad5686_state *st, u8 addr)
+{
+       struct spi_transfer t[] = {
+               {
+                       .tx_buf = &st->data[0].d8[1],
+                       .len = 3,
+                       .cs_change = 1,
+               }, {
+                       .tx_buf = &st->data[1].d8[1],
+                       .rx_buf = &st->data[2].d8[1],
+                       .len = 3,
+               },
+       };
+       struct spi_device *spi = to_spi_device(st->dev);
+       int ret;
+
+       st->data[0].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_READBACK_ENABLE) |
+                                     AD5686_ADDR(addr));
+       st->data[1].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_NOOP));
+
+       ret = spi_sync_transfer(spi, t, ARRAY_SIZE(t));
+       if (ret < 0)
+               return ret;
+
+       return be32_to_cpu(st->data[2].d32);
+}
+
+static int ad5686_spi_probe(struct spi_device *spi)
+{
+       const struct spi_device_id *id = spi_get_device_id(spi);
+
+       return ad5686_probe(&spi->dev, id->driver_data, id->name,
+                           ad5686_spi_write, ad5686_spi_read);
+}
+
+static int ad5686_spi_remove(struct spi_device *spi)
+{
+       return ad5686_remove(&spi->dev);
+}
+
+static const struct spi_device_id ad5686_spi_id[] = {
+       {"ad5672r", ID_AD5672R},
+       {"ad5676", ID_AD5676},
+       {"ad5676r", ID_AD5676R},
+       {"ad5684", ID_AD5684},
+       {"ad5684r", ID_AD5684R},
+       {"ad5685", ID_AD5685R}, /* Does not exist */
+       {"ad5685r", ID_AD5685R},
+       {"ad5686", ID_AD5686},
+       {"ad5686r", ID_AD5686R},
+       {}
+};
+MODULE_DEVICE_TABLE(spi, ad5686_spi_id);
+
+static struct spi_driver ad5686_spi_driver = {
+       .driver = {
+               .name = "ad5686",
+       },
+       .probe = ad5686_spi_probe,
+       .remove = ad5686_spi_remove,
+       .id_table = ad5686_spi_id,
+};
+
+module_spi_driver(ad5686_spi_driver);
+
+MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD5686 and similar multi-channel DACs");
+MODULE_LICENSE("GPL v2");
index 9e1a6ba..79abff5 100644 (file)
@@ -10,7 +10,6 @@
 #include <linux/device.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
-#include <linux/spi/spi.h>
 #include <linux/slab.h>
 #include <linux/sysfs.h>
 #include <linux/regulator/consumer.h>
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 
-#define AD5686_ADDR(x)                         ((x) << 16)
-#define AD5686_CMD(x)                          ((x) << 20)
-
-#define AD5686_ADDR_DAC(chan)                  (0x1 << (chan))
-#define AD5686_ADDR_ALL_DAC                    0xF
-
-#define AD5686_CMD_NOOP                                0x0
-#define AD5686_CMD_WRITE_INPUT_N               0x1
-#define AD5686_CMD_UPDATE_DAC_N                        0x2
-#define AD5686_CMD_WRITE_INPUT_N_UPDATE_N      0x3
-#define AD5686_CMD_POWERDOWN_DAC               0x4
-#define AD5686_CMD_LDAC_MASK                   0x5
-#define AD5686_CMD_RESET                       0x6
-#define AD5686_CMD_INTERNAL_REFER_SETUP                0x7
-#define AD5686_CMD_DAISY_CHAIN_ENABLE          0x8
-#define AD5686_CMD_READBACK_ENABLE             0x9
-
-#define AD5686_LDAC_PWRDN_NONE                 0x0
-#define AD5686_LDAC_PWRDN_1K                   0x1
-#define AD5686_LDAC_PWRDN_100K                 0x2
-#define AD5686_LDAC_PWRDN_3STATE               0x3
-
-/**
- * struct ad5686_chip_info - chip specific information
- * @int_vref_mv:       AD5620/40/60: the internal reference voltage
- * @num_channels:      number of channels
- * @channel:           channel specification
-*/
-
-struct ad5686_chip_info {
-       u16                             int_vref_mv;
-       unsigned int                    num_channels;
-       struct iio_chan_spec            *channels;
-};
-
-/**
- * struct ad5446_state - driver instance specific data
- * @spi:               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
- * @data:              spi transfer buffers
- */
-
-struct ad5686_state {
-       struct spi_device               *spi;
-       const struct ad5686_chip_info   *chip_info;
-       struct regulator                *reg;
-       unsigned short                  vref_mv;
-       unsigned                        pwr_down_mask;
-       unsigned                        pwr_down_mode;
-       /*
-        * 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;
-};
-
-/**
- * ad5686_supported_device_ids:
- */
-
-enum ad5686_supported_device_ids {
-       ID_AD5672R,
-       ID_AD5676,
-       ID_AD5676R,
-       ID_AD5684,
-       ID_AD5684R,
-       ID_AD5685R,
-       ID_AD5686,
-       ID_AD5686R
-};
-static int ad5686_spi_write(struct ad5686_state *st,
-                            u8 cmd, u8 addr, u16 val, u8 shift)
-{
-       val <<= shift;
-
-       st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
-                             AD5686_ADDR(addr) |
-                             val);
-
-       return spi_write(st->spi, &st->data[0].d8[1], 3);
-}
-
-static int ad5686_spi_read(struct ad5686_state *st, u8 addr)
-{
-       struct spi_transfer t[] = {
-               {
-                       .tx_buf = &st->data[0].d8[1],
-                       .len = 3,
-                       .cs_change = 1,
-               }, {
-                       .tx_buf = &st->data[1].d8[1],
-                       .rx_buf = &st->data[2].d8[1],
-                       .len = 3,
-               },
-       };
-       int ret;
-
-       st->data[0].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_READBACK_ENABLE) |
-                             AD5686_ADDR(addr));
-       st->data[1].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_NOOP));
-
-       ret = spi_sync_transfer(st->spi, t, ARRAY_SIZE(t));
-       if (ret < 0)
-               return ret;
-
-       return be32_to_cpu(st->data[2].d32);
-}
+#include "ad5686.h"
 
 static const char * const ad5686_powerdown_modes[] = {
        "1kohm_to_gnd",
@@ -195,8 +80,9 @@ static ssize_t ad5686_write_dac_powerdown(struct iio_dev *indio_dev,
        else
                st->pwr_down_mask &= ~(0x3 << (chan->channel * 2));
 
-       ret = ad5686_spi_write(st, AD5686_CMD_POWERDOWN_DAC, 0,
-                              st->pwr_down_mask & st->pwr_down_mode, 0);
+       ret = st->write(st, AD5686_CMD_POWERDOWN_DAC, 0,
+                       st->pwr_down_mask & st->pwr_down_mode);
+
 
        return ret ? ret : len;
 }
@@ -213,7 +99,7 @@ static int ad5686_read_raw(struct iio_dev *indio_dev,
        switch (m) {
        case IIO_CHAN_INFO_RAW:
                mutex_lock(&indio_dev->mlock);
-               ret = ad5686_spi_read(st, chan->address);
+               ret = st->read(st, chan->address);
                mutex_unlock(&indio_dev->mlock);
                if (ret < 0)
                        return ret;
@@ -242,11 +128,10 @@ static int ad5686_write_raw(struct iio_dev *indio_dev,
                        return -EINVAL;
 
                mutex_lock(&indio_dev->mlock);
-               ret = ad5686_spi_write(st,
-                                AD5686_CMD_WRITE_INPUT_N_UPDATE_N,
-                                chan->address,
-                                val,
-                                chan->scan_type.shift);
+               ret = st->write(st,
+                               AD5686_CMD_WRITE_INPUT_N_UPDATE_N,
+                               chan->address,
+                               val << chan->scan_type.shift);
                mutex_unlock(&indio_dev->mlock);
                break;
        default:
@@ -356,20 +241,27 @@ static const struct ad5686_chip_info ad5686_chip_info_tbl[] = {
        },
 };
 
-static int ad5686_probe(struct spi_device *spi)
+int ad5686_probe(struct device *dev,
+                enum ad5686_supported_device_ids chip_type,
+                const char *name, ad5686_write_func write,
+                ad5686_read_func read)
 {
        struct ad5686_state *st;
        struct iio_dev *indio_dev;
        int ret, voltage_uv = 0;
 
-       indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+       indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
        if (indio_dev == NULL)
                return  -ENOMEM;
 
        st = iio_priv(indio_dev);
-       spi_set_drvdata(spi, indio_dev);
+       dev_set_drvdata(dev, indio_dev);
+
+       st->dev = dev;
+       st->write = write;
+       st->read = read;
 
-       st->reg = devm_regulator_get_optional(&spi->dev, "vcc");
+       st->reg = devm_regulator_get_optional(dev, "vcc");
        if (!IS_ERR(st->reg)) {
                ret = regulator_enable(st->reg);
                if (ret)
@@ -382,28 +274,25 @@ static int ad5686_probe(struct spi_device *spi)
                voltage_uv = ret;
        }
 
-       st->chip_info =
-               &ad5686_chip_info_tbl[spi_get_device_id(spi)->driver_data];
+       st->chip_info = &ad5686_chip_info_tbl[chip_type];
 
        if (voltage_uv)
                st->vref_mv = voltage_uv / 1000;
        else
                st->vref_mv = st->chip_info->int_vref_mv;
 
-       st->spi = spi;
-
        /* Set all the power down mode for all channels to 1K pulldown */
        st->pwr_down_mode = 0x55;
 
-       indio_dev->dev.parent = &spi->dev;
-       indio_dev->name = spi_get_device_id(spi)->name;
+       indio_dev->dev.parent = dev;
+       indio_dev->name = name;
        indio_dev->info = &ad5686_info;
        indio_dev->modes = INDIO_DIRECT_MODE;
        indio_dev->channels = st->chip_info->channels;
        indio_dev->num_channels = st->chip_info->num_channels;
 
-       ret = ad5686_spi_write(st, AD5686_CMD_INTERNAL_REFER_SETUP, 0,
-                               !!voltage_uv, 0);
+       ret = st->write(st, AD5686_CMD_INTERNAL_REFER_SETUP,
+                       0, !!voltage_uv);
        if (ret)
                goto error_disable_reg;
 
@@ -418,10 +307,11 @@ error_disable_reg:
                regulator_disable(st->reg);
        return ret;
 }
+EXPORT_SYMBOL_GPL(ad5686_probe);
 
-static int ad5686_remove(struct spi_device *spi)
+int ad5686_remove(struct device *dev)
 {
-       struct iio_dev *indio_dev = spi_get_drvdata(spi);
+       struct iio_dev *indio_dev = dev_get_drvdata(dev);
        struct ad5686_state *st = iio_priv(indio_dev);
 
        iio_device_unregister(indio_dev);
@@ -430,30 +320,7 @@ static int ad5686_remove(struct spi_device *spi)
 
        return 0;
 }
-
-static const struct spi_device_id ad5686_id[] = {
-       {"ad5672r", ID_AD5672R},
-       {"ad5676", ID_AD5676},
-       {"ad5676r", ID_AD5676R},
-       {"ad5684", ID_AD5684},
-       {"ad5684r", ID_AD5684R},
-       {"ad5685", ID_AD5685R}, /* Does not exist */
-       {"ad5685r", ID_AD5685R},
-       {"ad5686", ID_AD5686},
-       {"ad5686r", ID_AD5686R},
-       {}
-};
-MODULE_DEVICE_TABLE(spi, ad5686_id);
-
-static struct spi_driver ad5686_driver = {
-       .driver = {
-                  .name = "ad5686",
-                  },
-       .probe = ad5686_probe,
-       .remove = ad5686_remove,
-       .id_table = ad5686_id,
-};
-module_spi_driver(ad5686_driver);
+EXPORT_SYMBOL_GPL(ad5686_remove);
 
 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>");
 MODULE_DESCRIPTION("Analog Devices AD5686/85/84 DAC");
diff --git a/drivers/iio/dac/ad5686.h b/drivers/iio/dac/ad5686.h
new file mode 100644 (file)
index 0000000..c8e1565
--- /dev/null
@@ -0,0 +1,114 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * This file is part of AD5686 DAC driver
+ *
+ * Copyright 2018 Analog Devices Inc.
+ */
+
+#ifndef __DRIVERS_IIO_DAC_AD5686_H__
+#define __DRIVERS_IIO_DAC_AD5686_H__
+
+#include <linux/types.h>
+#include <linux/cache.h>
+#include <linux/mutex.h>
+#include <linux/kernel.h>
+
+#define AD5686_ADDR(x)                         ((x) << 16)
+#define AD5686_CMD(x)                          ((x) << 20)
+
+#define AD5686_ADDR_DAC(chan)                  (0x1 << (chan))
+#define AD5686_ADDR_ALL_DAC                    0xF
+
+#define AD5686_CMD_NOOP                                0x0
+#define AD5686_CMD_WRITE_INPUT_N               0x1
+#define AD5686_CMD_UPDATE_DAC_N                        0x2
+#define AD5686_CMD_WRITE_INPUT_N_UPDATE_N      0x3
+#define AD5686_CMD_POWERDOWN_DAC               0x4
+#define AD5686_CMD_LDAC_MASK                   0x5
+#define AD5686_CMD_RESET                       0x6
+#define AD5686_CMD_INTERNAL_REFER_SETUP                0x7
+#define AD5686_CMD_DAISY_CHAIN_ENABLE          0x8
+#define AD5686_CMD_READBACK_ENABLE             0x9
+
+#define AD5686_LDAC_PWRDN_NONE                 0x0
+#define AD5686_LDAC_PWRDN_1K                   0x1
+#define AD5686_LDAC_PWRDN_100K                 0x2
+#define AD5686_LDAC_PWRDN_3STATE               0x3
+
+/**
+ * ad5686_supported_device_ids:
+ */
+enum ad5686_supported_device_ids {
+       ID_AD5672R,
+       ID_AD5676,
+       ID_AD5676R,
+       ID_AD5684,
+       ID_AD5684R,
+       ID_AD5685R,
+       ID_AD5686,
+       ID_AD5686R,
+};
+
+struct ad5686_state;
+
+typedef int (*ad5686_write_func)(struct ad5686_state *st,
+                                u8 cmd, u8 addr, u16 val);
+
+typedef int (*ad5686_read_func)(struct ad5686_state *st, u8 addr);
+
+/**
+ * struct ad5686_chip_info - chip specific information
+ * @int_vref_mv:       AD5620/40/60: the internal reference voltage
+ * @num_channels:      number of channels
+ * @channel:           channel specification
+ */
+
+struct ad5686_chip_info {
+       u16                             int_vref_mv;
+       unsigned int                    num_channels;
+       struct iio_chan_spec            *channels;
+};
+
+/**
+ * struct ad5446_state - driver instance specific data
+ * @spi:               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
+ * @data:              spi transfer buffers
+ */
+
+struct ad5686_state {
+       struct device                   *dev;
+       const struct ad5686_chip_info   *chip_info;
+       struct regulator                *reg;
+       unsigned short                  vref_mv;
+       unsigned int                    pwr_down_mask;
+       unsigned int                    pwr_down_mode;
+       ad5686_write_func               write;
+       ad5686_read_func                read;
+
+       /*
+        * DMA (thus cache coherency maintenance) requires the
+        * transfer buffers to live in their own cache lines.
+        */
+
+       union {
+               __be32 d32;
+               __be16 d16;
+               u8 d8[4];
+       } data[3] ____cacheline_aligned;
+};
+
+
+int ad5686_probe(struct device *dev,
+                enum ad5686_supported_device_ids chip_type,
+                const char *name, ad5686_write_func write,
+                ad5686_read_func read);
+
+int ad5686_remove(struct device *dev);
+
+
+#endif /* __DRIVERS_IIO_DAC_AD5686_H__ */