[PATCH v2 1/6] iio: imu: adis: Add optional self_test callback and fix custom reset dispatch

[Radu Sabau via B4 Relay <devnull+radu.sabau.analog.com@kernel.org>]

From: Radu Sabau <radu.sabau@analog.com>

Add an optional self_test callback to struct adis_data, for devices
whose self-test doesn't fit the generic mask-write/sleep/check-status
sequence. Purely additive: defaults to NULL, no change for existing
drivers.

Also fix __adis_initial_startup()'s no-reset-gpio path: it called
__adis_reset() directly instead of adis->ops->reset(), silently
ignoring any driver's custom reset implementation. Invisible until now
since adis_default_ops.reset is __adis_reset() itself. Dispatch
through adis->ops->reset() instead, adding the settle-time sleep at
the call site for custom ops (documented not to sleep internally)
while skipping it for the default op (which already sleeps
internally).

Fixes: ecb010d44108 ("iio: imu: adis: Refactor adis_initial_startup")
Signed-off-by: Radu Sabau <radu.sabau@analog.com>
---
 drivers/iio/imu/adis.c       | 30 +++++++++++++++++++++++-------
 include/linux/iio/imu/adis.h | 14 ++++++++++++++
 2 files changed, 37 insertions(+), 7 deletions(-)

diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c
index a2bc1d14ed91..306777526a11 100644
--- a/drivers/iio/imu/adis.c
+++ b/drivers/iio/imu/adis.c
@@ -355,11 +355,20 @@ int __adis_reset(struct adis *adis)
 }
 EXPORT_SYMBOL_NS_GPL(__adis_reset, "IIO_ADIS_LIB");
 
+static const struct adis_ops adis_default_ops = {
+	.read = __adis_read_reg,
+	.write = __adis_write_reg,
+	.reset = __adis_reset,
+};
+
 static int adis_self_test(struct adis *adis)
 {
 	int ret;
 	const struct adis_timeout *timeouts = adis->data->timeouts;
 
+	if (adis->data->self_test)
+		return adis->data->self_test(adis);
+
 	ret = __adis_write_reg_16(adis, adis->data->self_test_reg,
 				  adis->data->self_test_mask);
 	if (ret) {
@@ -413,7 +422,20 @@ int __adis_initial_startup(struct adis *adis)
 		gpiod_set_value_cansleep(gpio, 0);
 		msleep(timeouts->reset_ms);
 	} else {
-		ret = __adis_reset(adis);
+		ret = adis->ops->reset(adis);
+		if (ret)
+			return ret;
+		/*
+		 * The default reset op (__adis_reset()) already sleeps the
+		 * settle time internally. Custom reset ops are documented
+		 * (struct adis_ops::reset) not to, so sleep here for them.
+		 */
+		if (adis->ops != &adis_default_ops)
+			msleep(timeouts->sw_reset_ms);
+	}
+
+	if (adis->data->post_reset_setup) {
+		ret = adis->data->post_reset_setup(adis);
 		if (ret)
 			return ret;
 	}
@@ -491,12 +513,6 @@ int adis_single_conversion(struct iio_dev *indio_dev,
 }
 EXPORT_SYMBOL_NS_GPL(adis_single_conversion, "IIO_ADISLIB");
 
-static const struct adis_ops adis_default_ops = {
-	.read = __adis_read_reg,
-	.write = __adis_write_reg,
-	.reset = __adis_reset,
-};
-
 /**
  * adis_init() - Initialize adis device structure
  * @adis:	The adis device
diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h
index bfb6df68e6c9..06058843e02b 100644
--- a/include/linux/iio/imu/adis.h
+++ b/include/linux/iio/imu/adis.h
@@ -51,6 +51,18 @@ struct adis_timeout {
  * @self_test_mask: Bitmask of supported self-test operations
  * @self_test_reg: Register address to request self test command
  * @self_test_no_autoclear: True if device's self-test needs clear of ctrl reg
+ * @post_reset_setup: Optional device-specific hook called after reset,
+ *		before self-test. Not all ADIS devices need extra bring-up
+ *		between reset and self-test (SPI mode locking, status or
+ *		bootloader checks, pin or burst-mode configuration, etc.) -
+ *		only called when set. Must return 0 on success, a negative
+ *		error code otherwise.
+ * @self_test: Optional device-specific self-test override. When set,
+ *		it is called instead of the generic mask-write/sleep/
+ *		check-status sequence. The callback owns its own pass/fail
+ *		determination entirely (it should call __adis_check_status()
+ *		itself if it wants status-register checks). Must return 0 on
+ *		success, a negative error code otherwise.
  * @status_error_msgs: Array of error messages
  * @status_error_mask: Bitmask of errors supported by the device
  * @timeouts: Chip specific delays
@@ -81,6 +93,8 @@ struct adis_data {
 	unsigned int self_test_mask;
 	unsigned int self_test_reg;
 	bool self_test_no_autoclear;
+	int (*post_reset_setup)(struct adis *adis);
+	int (*self_test)(struct adis *adis);
 	const struct adis_timeout *timeouts;
 
 	const char * const *status_error_msgs;

-- 
2.43.0