Re: [PATCH v1.1 2/2] iio: dac: dac5571: Fix chip id detection for OF devices
From: Jonathan Cameron <jic23@kernel.org>
Date: 2021-07-24 14:42:14
Also in:
linux-i2c, linux-iio
On Sat, 24 Jul 2021 03:06:54 +0300 Laurent Pinchart [off-list ref] wrote:
From: Jose Cazarin <redacted>
When matching an OF device, the match mechanism tries all components of
the compatible property. This can result with a device matched with a
compatible string that isn't the first in the compatible list. For
instance, with a compatible property set to
compatible = "ti,dac081c081", "ti,dac5571";
the driver will match the second compatible string, as the first one
isn't listed in the of_device_id table. The device will however be named
"dac081c081" by the I2C core.
This causes an issue when identifying the chip. The probe function
receives a i2c_device_id that comes from the module's I2C device ID
table. There is no entry in that table for "dac081c081", which results
in a NULL pointer passed to the probe function.
To fix this, add chip_id information in the data field of the OF device
ID table, and retrieve it with of_device_get_match_data() for OF
devices.
Signed-off-by: Jose Cazarin <redacted>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>Side note I failed to put in the review email. I definitely prefer a whole new series even when a change is just to a single patch like this. Much easier to track and eventually pick up as one unit. Thanks, Jonathan
quoted hunk ↗ jump to hunk
--- Changes since v1: - Include linux/of_device.h --- drivers/iio/dac/ti-dac5571.c | 28 ++++++++++++++++++---------- 1 file changed, 18 insertions(+), 10 deletions(-)diff --git a/drivers/iio/dac/ti-dac5571.c b/drivers/iio/dac/ti-dac5571.c index 2a5ba1b08a1d..8ceb1b42b14e 100644 --- a/drivers/iio/dac/ti-dac5571.c +++ b/drivers/iio/dac/ti-dac5571.c@@ -19,6 +19,7 @@ #include <linux/i2c.h> #include <linux/module.h> #include <linux/mod_devicetable.h> +#include <linux/of_device.h> #include <linux/regulator/consumer.h> enum chip_id {@@ -311,6 +312,7 @@ static int dac5571_probe(struct i2c_client *client, const struct dac5571_spec *spec; struct dac5571_data *data; struct iio_dev *indio_dev; + enum chip_id chip_id; int ret, i; indio_dev = devm_iio_device_alloc(dev, sizeof(*data));@@ -326,7 +328,13 @@ static int dac5571_probe(struct i2c_client *client, indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = dac5571_channels; - spec = &dac5571_spec[id->driver_data]; + if (dev->of_node) + chip_id = (uintptr_t)of_device_get_match_data(dev); + else + chip_id = id->driver_data; + + spec = &dac5571_spec[chip_id]; + indio_dev->num_channels = spec->num_channels; data->spec = spec;@@ -384,15 +392,15 @@ static int dac5571_remove(struct i2c_client *i2c) } static const struct of_device_id dac5571_of_id[] = { - {.compatible = "ti,dac5571"}, - {.compatible = "ti,dac6571"}, - {.compatible = "ti,dac7571"}, - {.compatible = "ti,dac5574"}, - {.compatible = "ti,dac6574"}, - {.compatible = "ti,dac7574"}, - {.compatible = "ti,dac5573"}, - {.compatible = "ti,dac6573"}, - {.compatible = "ti,dac7573"}, + {.compatible = "ti,dac5571", .data = (void *)single_8bit}, + {.compatible = "ti,dac6571", .data = (void *)single_10bit}, + {.compatible = "ti,dac7571", .data = (void *)single_12bit}, + {.compatible = "ti,dac5574", .data = (void *)quad_8bit}, + {.compatible = "ti,dac6574", .data = (void *)quad_10bit}, + {.compatible = "ti,dac7574", .data = (void *)quad_12bit}, + {.compatible = "ti,dac5573", .data = (void *)quad_8bit}, + {.compatible = "ti,dac6573", .data = (void *)quad_10bit}, + {.compatible = "ti,dac7573", .data = (void *)quad_12bit}, {} }; MODULE_DEVICE_TABLE(of, dac5571_of_id);