iio: max517: Add support for MAX520 and MAX521 chips.

MAX520 and MAX521 are protocol-compatible with the already supported
chips, just have more channels.

Signed-off-by: Antonio Fiol <antonio@fiol.es>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

3 files changed, 42 insertions, 16 deletions

diff --git a/drivers/iio/dac/Kconfig b/drivers/iio/dac/Kconfig
index 2236ea22f98a..13471a76e5bf 100644
--- a/drivers/iio/dac/Kconfig
+++ b/drivers/iio/dac/Kconfig
@@ -143,11 +143,16 @@ config AD7303
           ad7303.
 
 config MAX517
-        tristate "Maxim MAX517/518/519 DAC driver"
+        tristate "Maxim MAX517/518/519/520/521 DAC driver"
         depends on I2C
         help
-          If you say yes here you get support for the Maxim chips MAX517,
-          MAX518 and MAX519 (I2C 8-Bit DACs with rail-to-rail outputs).
+          If you say yes here you get support for the following Maxim chips
+          (I2C 8-Bit DACs with rail-to-rail outputs):
+          MAX517 - Single channel, single reference
+          MAX518 - Dual channel, ref=Vdd
+          MAX519 - Dual channel, dual reference
+          MAX520 - Quad channel, quad reference
+          MAX521 - Octal channel, independent ref for ch0-3, shared ref for ch4-7
 
           This driver can also be built as a module.  If so, the module
           will be called max517.
diff --git a/drivers/iio/dac/max517.c b/drivers/iio/dac/max517.c
index 9a82a7255ebb..5507b3970b4b 100644
--- a/drivers/iio/dac/max517.c
+++ b/drivers/iio/dac/max517.c
@@ -39,11 +39,13 @@ enum max517_device_ids {
         ID_MAX517,
         ID_MAX518,
         ID_MAX519,
+        ID_MAX520,
+        ID_MAX521,
 };
 
 struct max517_data {
         struct i2c_client       *client;
-        unsigned short          vref_mv[2];
+        unsigned short          vref_mv[8];
 };
 
 /*
@@ -149,7 +151,13 @@ static const struct iio_info max517_info = {
 
 static const struct iio_chan_spec max517_channels[] = {
         MAX517_CHANNEL(0),
-        MAX517_CHANNEL(1)
+        MAX517_CHANNEL(1),
+        MAX517_CHANNEL(2),
+        MAX517_CHANNEL(3),
+        MAX517_CHANNEL(4),
+        MAX517_CHANNEL(5),
+        MAX517_CHANNEL(6),
+        MAX517_CHANNEL(7),
 };
 
 static int max517_probe(struct i2c_client *client,
@@ -158,6 +166,7 @@ static int max517_probe(struct i2c_client *client,
         struct max517_data *data;
         struct iio_dev *indio_dev;
         struct max517_platform_data *platform_data = client->dev.platform_data;
+        int chan;
 
         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
         if (!indio_dev)
@@ -169,11 +178,21 @@ static int max517_probe(struct i2c_client *client,
         /* establish that the iio_dev is a child of the i2c device */
         indio_dev->dev.parent = &client->dev;
 
-        /* reduced channel set for MAX517 */
-        if (id->driver_data == ID_MAX517)
-                indio_dev->num_channels = 1;
-        else
+        switch (id->driver_data) {
+        case ID_MAX521:
+                indio_dev->num_channels = 8;
+                break;
+        case ID_MAX520:
+                indio_dev->num_channels = 4;
+                break;
+        case ID_MAX519:
+        case ID_MAX518:
                 indio_dev->num_channels = 2;
+                break;
+        default:  /* single channel for MAX517 */
+                indio_dev->num_channels = 1;
+                break;
+        }
         indio_dev->channels = max517_channels;
         indio_dev->modes = INDIO_DIRECT_MODE;
         indio_dev->info = &max517_info;
@@ -182,11 +201,11 @@ static int max517_probe(struct i2c_client *client,
          * Reference voltage on MAX518 and default is 5V, else take vref_mv
          * from platform_data
          */
-        if (id->driver_data == ID_MAX518 || !platform_data) {
-                data->vref_mv[0] = data->vref_mv[1] = 5000; /* mV */
-        } else {
-                data->vref_mv[0] = platform_data->vref_mv[0];
-                data->vref_mv[1] = platform_data->vref_mv[1];
+        for (chan = 0; chan < indio_dev->num_channels; chan++) {
+                if (id->driver_data == ID_MAX518 || !platform_data)
+                        data->vref_mv[chan] = 5000; /* mV */
+                else
+                        data->vref_mv[chan] = platform_data->vref_mv[chan];
         }
 
         return iio_device_register(indio_dev);
@@ -202,6 +221,8 @@ static const struct i2c_device_id max517_id[] = {
         { "max517", ID_MAX517 },
         { "max518", ID_MAX518 },
         { "max519", ID_MAX519 },
+        { "max520", ID_MAX520 },
+        { "max521", ID_MAX521 },
         { }
 };
 MODULE_DEVICE_TABLE(i2c, max517_id);
@@ -218,5 +239,5 @@ static struct i2c_driver max517_driver = {
 module_i2c_driver(max517_driver);
 
 MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
-MODULE_DESCRIPTION("MAX517/MAX518/MAX519 8-bit DAC");
+MODULE_DESCRIPTION("MAX517/518/519/520/521 8-bit DAC");
 MODULE_LICENSE("GPL");
diff --git a/include/linux/iio/dac/max517.h b/include/linux/iio/dac/max517.h
index f6d1d252f08d..7668716cd73c 100644
--- a/include/linux/iio/dac/max517.h
+++ b/include/linux/iio/dac/max517.h
@@ -9,7 +9,7 @@
 #define IIO_DAC_MAX517_H_
 
 struct max517_platform_data {
-        u16                             vref_mv[2];
+        u16                             vref_mv[8];
 };
 
 #endif /* IIO_DAC_MAX517_H_ */