iio: chemical: vz89x: abstract chip configuration

Abstract chip configuration data to allow supporting multiple variants
of the VZ89 chemical sensor line.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 62 insertions, 18 deletions

diff --git a/drivers/iio/chemical/vz89x.c b/drivers/iio/chemical/vz89x.c
index 652649da500f..aa6ebc084e19 100644
--- a/drivers/iio/chemical/vz89x.c
+++ b/drivers/iio/chemical/vz89x.c
@@ -19,25 +19,45 @@
 #include <linux/mutex.h>
 #include <linux/init.h>
 #include <linux/i2c.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
 
 #include <linux/iio/iio.h>
 #include <linux/iio/sysfs.h>
 
 #define VZ89X_REG_MEASUREMENT           0x09
-#define VZ89X_REG_MEASUREMENT_SIZE      6
+#define VZ89X_REG_MEASUREMENT_RD_SIZE   6
+#define VZ89X_REG_MEASUREMENT_WR_SIZE   3
 
 #define VZ89X_VOC_CO2_IDX               0
 #define VZ89X_VOC_SHORT_IDX             1
 #define VZ89X_VOC_TVOC_IDX              2
 #define VZ89X_VOC_RESISTANCE_IDX        3
 
+enum {
+        VZ89X,
+};
+
+struct vz89x_chip_data;
+
 struct vz89x_data {
         struct i2c_client *client;
+        const struct vz89x_chip_data *chip;
         struct mutex lock;
         int (*xfer)(struct vz89x_data *data, u8 cmd);
 
         unsigned long last_update;
-        u8 buffer[VZ89X_REG_MEASUREMENT_SIZE];
+        u8 buffer[VZ89X_REG_MEASUREMENT_RD_SIZE];
+};
+
+struct vz89x_chip_data {
+        bool (*valid)(struct vz89x_data *data);
+        const struct iio_chan_spec *channels;
+        u8 num_channels;
+
+        u8 cmd;
+        u8 read_size;
+        u8 write_size;
 };
 
 static const struct iio_chan_spec vz89x_channels[] = {
@@ -93,16 +113,17 @@ static const struct attribute_group vz89x_attrs_group = {
  * always zero, and by also confirming the VOC_short isn't zero.
  */
 
-static int vz89x_measurement_is_valid(struct vz89x_data *data)
+static bool vz89x_measurement_is_valid(struct vz89x_data *data)
 {
         if (data->buffer[VZ89X_VOC_SHORT_IDX] == 0)
                 return 1;
 
-        return !!(data->buffer[VZ89X_REG_MEASUREMENT_SIZE - 1] > 0);
+        return !!(data->buffer[data->chip->read_size - 1] > 0);
 }
 
 static int vz89x_i2c_xfer(struct vz89x_data *data, u8 cmd)
 {
+        const struct vz89x_chip_data *chip = data->chip;
         struct i2c_client *client = data->client;
         struct i2c_msg msg[2];
         int ret;
@@ -110,12 +131,12 @@ static int vz89x_i2c_xfer(struct vz89x_data *data, u8 cmd)
 
         msg[0].addr = client->addr;
         msg[0].flags = client->flags;
-        msg[0].len = 3;
+        msg[0].len = chip->write_size;
         msg[0].buf  = (char *) &buf;
 
         msg[1].addr = client->addr;
         msg[1].flags = client->flags | I2C_M_RD;
-        msg[1].len = VZ89X_REG_MEASUREMENT_SIZE;
+        msg[1].len = chip->read_size;
         msg[1].buf = (char *) &data->buffer;
 
         ret = i2c_transfer(client->adapter, msg, 2);
@@ -133,7 +154,7 @@ static int vz89x_smbus_xfer(struct vz89x_data *data, u8 cmd)
         if (ret < 0)
                 return ret;
 
-        for (i = 0; i < VZ89X_REG_MEASUREMENT_SIZE; i++) {
+        for (i = 0; i < data->chip->read_size; i++) {
                 ret = i2c_smbus_read_byte(client);
                 if (ret < 0)
                         return ret;
@@ -145,17 +166,18 @@ static int vz89x_smbus_xfer(struct vz89x_data *data, u8 cmd)
 
 static int vz89x_get_measurement(struct vz89x_data *data)
 {
+        const struct vz89x_chip_data *chip = data->chip;
         int ret;
 
         /* sensor can only be polled once a second max per datasheet */
         if (!time_after(jiffies, data->last_update + HZ))
                 return 0;
 
-        ret = data->xfer(data, VZ89X_REG_MEASUREMENT);
+        ret = data->xfer(data, chip->cmd);
         if (ret < 0)
                 return ret;
 
-        ret = vz89x_measurement_is_valid(data);
+        ret = chip->valid(data);
         if (ret)
                 return -EAGAIN;
 
@@ -232,11 +254,32 @@ static const struct iio_info vz89x_info = {
         .driver_module  = THIS_MODULE,
 };
 
+static const struct vz89x_chip_data vz89x_chips[] = {
+        {
+                .valid = vz89x_measurement_is_valid,
+
+                .cmd = VZ89X_REG_MEASUREMENT,
+                .read_size = VZ89X_REG_MEASUREMENT_RD_SIZE,
+                .write_size = VZ89X_REG_MEASUREMENT_WR_SIZE,
+
+                .channels = vz89x_channels,
+                .num_channels = ARRAY_SIZE(vz89x_channels),
+        },
+};
+
+static const struct of_device_id vz89x_dt_ids[] = {
+        { .compatible = "sgx,vz89x", .data = (void *) VZ89X },
+        { }
+};
+MODULE_DEVICE_TABLE(of, vz89x_dt_ids);
+
 static int vz89x_probe(struct i2c_client *client,
                        const struct i2c_device_id *id)
 {
         struct iio_dev *indio_dev;
         struct vz89x_data *data;
+        const struct of_device_id *of_id;
+        int chip_id;
 
         indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
         if (!indio_dev)
@@ -251,8 +294,15 @@ static int vz89x_probe(struct i2c_client *client,
         else
                 return -EOPNOTSUPP;
 
+        of_id = of_match_device(vz89x_dt_ids, &client->dev);
+        if (!of_id)
+                chip_id = id->driver_data;
+        else
+                chip_id = (unsigned long)of_id->data;
+
         i2c_set_clientdata(client, indio_dev);
         data->client = client;
+        data->chip = &vz89x_chips[chip_id];
         data->last_update = jiffies - HZ;
         mutex_init(&data->lock);
 
@@ -261,24 +311,18 @@ static int vz89x_probe(struct i2c_client *client,
         indio_dev->name = dev_name(&client->dev);
         indio_dev->modes = INDIO_DIRECT_MODE;
 
-        indio_dev->channels = vz89x_channels;
-        indio_dev->num_channels = ARRAY_SIZE(vz89x_channels);
+        indio_dev->channels = data->chip->channels;
+        indio_dev->num_channels = data->chip->num_channels;
 
         return devm_iio_device_register(&client->dev, indio_dev);
 }
 
 static const struct i2c_device_id vz89x_id[] = {
-        { "vz89x", 0 },
+        { "vz89x", VZ89X },
         { }
 };
 MODULE_DEVICE_TABLE(i2c, vz89x_id);
 
-static const struct of_device_id vz89x_dt_ids[] = {
-        { .compatible = "sgx,vz89x" },
-        { }
-};
-MODULE_DEVICE_TABLE(of, vz89x_dt_ids);
-
 static struct i2c_driver vz89x_driver = {
         .driver = {
                 .name   = "vz89x",