staging: iio: ad7816: Do not use busy_pin in case of AD7818

AD7818 does not support busy_pin functionality as per datasheet.
Hence drop busy_pin when AD7818 is used.

Signed-off-by: Nishad Kamdar <nishadkamdar@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

diff --git a/drivers/staging/iio/adc/ad7816.c b/drivers/staging/iio/adc/ad7816.c
index 12c4e0a..3cda5cd 100644 (file)
--- a/drivers/staging/iio/adc/ad7816.c
+++ b/drivers/staging/iio/adc/ad7816.c
@@ -43,6 +43,7 @@
  */
 
 struct ad7816_chip_info {
+       kernel_ulong_t id;
        struct spi_device *spi_dev;
        struct gpio_desc *rdwr_pin;
        struct gpio_desc *convert_pin;
@@ -52,6 +53,12 @@ struct ad7816_chip_info {
        u8  mode;
 };
 
+enum ad7816_type {
+       ID_AD7816,
+       ID_AD7817,
+       ID_AD7818,
+};
+
 /*
  * ad7816 data access by SPI
  */
@@ -78,8 +85,10 @@ static int ad7816_spi_read(struct ad7816_chip_info *chip, u16 *data)
                gpiod_set_value(chip->convert_pin, 1);
        }
 
-       while (gpiod_get_value(chip->busy_pin))
-               cpu_relax();
+       if (chip->id == ID_AD7816 || chip->id == ID_AD7817) {
+               while (gpiod_get_value(chip->busy_pin))
+                       cpu_relax();
+       }
 
        gpiod_set_value(chip->rdwr_pin, 0);
        gpiod_set_value(chip->rdwr_pin, 1);
@@ -359,6 +368,7 @@ static int ad7816_probe(struct spi_device *spi_dev)
        for (i = 0; i <= AD7816_CS_MAX; i++)
                chip->oti_data[i] = 203;
 
+       chip->id = spi_get_device_id(spi_dev)->driver_data;
        chip->rdwr_pin = devm_gpiod_get(&spi_dev->dev, "rdwr", GPIOD_IN);
        if (IS_ERR(chip->rdwr_pin)) {
                ret = PTR_ERR(chip->rdwr_pin);
@@ -373,12 +383,15 @@ static int ad7816_probe(struct spi_device *spi_dev)
                        ret);
                return ret;
        }
-       chip->busy_pin = devm_gpiod_get(&spi_dev->dev, "busy", GPIOD_IN);
-       if (IS_ERR(chip->busy_pin)) {
-               ret = PTR_ERR(chip->busy_pin);
-               dev_err(&spi_dev->dev, "Failed to request busy GPIO: %d\n",
-                       ret);
-               return ret;
+       if (chip->id == ID_AD7816 || chip->id == ID_AD7817) {
+               chip->busy_pin = devm_gpiod_get(&spi_dev->dev, "busy",
+                                               GPIOD_IN);
+               if (IS_ERR(chip->busy_pin)) {
+                       ret = PTR_ERR(chip->busy_pin);
+                       dev_err(&spi_dev->dev, "Failed to request busy GPIO: %d\n",
+                               ret);
+                       return ret;
+               }
        }
 
        indio_dev->name = spi_get_device_id(spi_dev)->name;
@@ -409,9 +422,9 @@ static int ad7816_probe(struct spi_device *spi_dev)
 }
 
 static const struct spi_device_id ad7816_id[] = {
-       { "ad7816", 0 },
-       { "ad7817", 0 },
-       { "ad7818", 0 },
+       { "ad7816", ID_AD7816 },
+       { "ad7817", ID_AD7817 },
+       { "ad7818", ID_AD7818 },
        {}
 };