1 files changed, 54 insertions, 1 deletions

diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
index 799ae04301be..2967aa2a74e2 100644
--- a/drivers/fpga/xilinx-spi.c
+++ b/drivers/fpga/xilinx-spi.c
@@ -23,6 +23,7 @@
 struct xilinx_spi_conf {
 	struct spi_device *spi;
 	struct gpio_desc *prog_b;
+	struct gpio_desc *init_b;
 	struct gpio_desc *done;
 };
 
@@ -36,11 +37,45 @@ static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr)
 	return FPGA_MGR_STATE_UNKNOWN;
 }
 
+/**
+ * wait_for_init_b - wait for the INIT_B pin to have a given state, or wait
+ * a given delay if the pin is unavailable
+ *
+ * @mgr:        The FPGA manager object
+ * @value:      Value INIT_B to wait for (1 = asserted = low)
+ * @alt_udelay: Delay to wait if the INIT_B GPIO is not available
+ *
+ * Returns 0 when the INIT_B GPIO reached the given state or -ETIMEDOUT if
+ * too much time passed waiting for that. If no INIT_B GPIO is available
+ * then always return 0.
+ */
+static int wait_for_init_b(struct fpga_manager *mgr, int value,
+			   unsigned long alt_udelay)
+{
+	struct xilinx_spi_conf *conf = mgr->priv;
+	unsigned long timeout = jiffies + msecs_to_jiffies(1000);
+
+	if (conf->init_b) {
+		while (time_before(jiffies, timeout)) {
+			/* dump_state(conf, "wait for init_d .."); */
+			if (gpiod_get_value(conf->init_b) == value)
+				return 0;
+			usleep_range(100, 400);
+		}
+		return -ETIMEDOUT;
+	}
+
+	udelay(alt_udelay);
+
+	return 0;
+}
+
 static int xilinx_spi_write_init(struct fpga_manager *mgr,
 				 struct fpga_image_info *info,
 				 const char *buf, size_t count)
 {
 	struct xilinx_spi_conf *conf = mgr->priv;
+	int err;
 
 	if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
 		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
@@ -49,10 +84,21 @@ static int xilinx_spi_write_init(struct fpga_manager *mgr,
 
 	gpiod_set_value(conf->prog_b, 1);
 
-	udelay(1); /* min is 500 ns */
+	err = wait_for_init_b(mgr, 1, 1); /* min is 500 ns */
+	if (err) {
+		dev_err(&mgr->dev, "INIT_B pin did not go low\n");
+		gpiod_set_value(conf->prog_b, 0);
+		return err;
+	}
 
 	gpiod_set_value(conf->prog_b, 0);
 
+	err = wait_for_init_b(mgr, 0, 0);
+	if (err) {
+		dev_err(&mgr->dev, "INIT_B pin did not go high\n");
+		return err;
+	}
+
 	if (gpiod_get_value(conf->done)) {
 		dev_err(&mgr->dev, "Unexpected DONE pin state...\n");
 		return -EIO;
@@ -154,6 +200,13 @@ static int xilinx_spi_probe(struct spi_device *spi)
 		return PTR_ERR(conf->prog_b);
 	}
 
+	conf->init_b = devm_gpiod_get_optional(&spi->dev, "init-b", GPIOD_IN);
+	if (IS_ERR(conf->init_b)) {
+		dev_err(&spi->dev, "Failed to get INIT_B gpio: %ld\n",
+			PTR_ERR(conf->init_b));
+		return PTR_ERR(conf->init_b);
+	}
+
 	conf->done = devm_gpiod_get(&spi->dev, "done", GPIOD_IN);
 	if (IS_ERR(conf->done)) {
 		dev_err(&spi->dev, "Failed to get DONE gpio: %ld\n",