Merge tag 'fpga-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mdf/linux-fpga into char-misc-next

Moritz writes:

FPGA Manager changes for 5.8

Here's the first set of changes for the 5.8-rc1 merge window.

Dominic's change adds support for accessing AFU regions with gdb.
Gustavo's change is a cleanup patch regarding variable lenght arrays.
Richard's changes update dt-bindings and add support for stratix and agilex.
Sergiu's changes update spi transfers with the new delay field.
Xu's change addresses an issue with a wrong return value.
Shubhrajyoti's change makes the Zynq FPGA driver return -EPROBE_DEFER on
check of devm_clk_get failure.
Xu's change for DFL enables multiple opens.

All of these patches have been reviewed, have appropriate Acked-by's and
have been in the last few linux-next releases without issues.

Signed-off-by: Moritz Fischer <mdf@kernel.org>

* tag 'fpga-for-5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mdf/linux-fpga:
  fpga: dfl: afu: support debug access to memory-mapped afu regions
  fpga: dfl.h: Replace zero-length array with flexible-array member
  arm64: dts: agilex: correct service layer driver's compatible value
  dt-bindings, firmware: add compatible value Intel Stratix10 service layer binding
  fpga: stratix10-soc: add compatible property value for intel agilex
  arm64: dts: agilex: correct FPGA manager driver's compatible value
  dt-bindings: fpga: add compatible value to Stratix10 SoC FPGA manager binding
  fpga: machxo2-spi: Use new structure for SPI transfer delays
  fpga: ice40-spi: Use new structure for SPI transfer delays
  fpga: dfl: support multiple opens on feature device node.

1 files changed, 28 insertions, 9 deletions

diff --git a/drivers/fpga/dfl.h b/drivers/fpga/dfl.h
index d312678a9aca..2f5d3052e36e 100644
--- a/drivers/fpga/dfl.h
+++ b/drivers/fpga/dfl.h
@@ -207,8 +207,6 @@ struct dfl_feature {
 	void *priv;
 };
 
-#define DEV_STATUS_IN_USE	0
-
 #define FEATURE_DEV_ID_UNUSED	(-1)
 
 /**
@@ -221,8 +219,9 @@ struct dfl_feature {
  * @dfl_cdev: ptr to container device.
  * @id: id used for this feature device.
  * @disable_count: count for port disable.
+ * @excl_open: set on feature device exclusive open.
+ * @open_count: count for feature device open.
  * @num: number for sub features.
- * @dev_status: dev status (e.g. DEV_STATUS_IN_USE).
  * @private: ptr to feature dev private data.
  * @features: sub features of this feature dev.
  */
@@ -234,26 +233,46 @@ struct dfl_feature_platform_data {
 	struct dfl_fpga_cdev *dfl_cdev;
 	int id;
 	unsigned int disable_count;
-	unsigned long dev_status;
+	bool excl_open;
+	int open_count;
 	void *private;
 	int num;
-	struct dfl_feature features[0];
+	struct dfl_feature features[];
 };
 
 static inline
-int dfl_feature_dev_use_begin(struct dfl_feature_platform_data *pdata)
+int dfl_feature_dev_use_begin(struct dfl_feature_platform_data *pdata,
+			      bool excl)
 {
-	/* Test and set IN_USE flags to ensure file is exclusively used */
-	if (test_and_set_bit_lock(DEV_STATUS_IN_USE, &pdata->dev_status))
+	if (pdata->excl_open)
 		return -EBUSY;
 
+	if (excl) {
+		if (pdata->open_count)
+			return -EBUSY;
+
+		pdata->excl_open = true;
+	}
+	pdata->open_count++;
+
 	return 0;
 }
 
 static inline
 void dfl_feature_dev_use_end(struct dfl_feature_platform_data *pdata)
 {
-	clear_bit_unlock(DEV_STATUS_IN_USE, &pdata->dev_status);
+	pdata->excl_open = false;
+
+	if (WARN_ON(pdata->open_count <= 0))
+		return;
+
+	pdata->open_count--;
+}
+
+static inline
+int dfl_feature_dev_use_count(struct dfl_feature_platform_data *pdata)
+{
+	return pdata->open_count;
 }
 
 static inline