1 files changed, 119 insertions, 48 deletions

diff --git a/drivers/fpga/xilinx-spi.c b/drivers/fpga/xilinx-spi.c
index 272ee0c22822..e1a227e7ff2a 100644
--- a/drivers/fpga/xilinx-spi.c
+++ b/drivers/fpga/xilinx-spi.c
@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * Xilinx Spartan6 Slave Serial SPI Driver
+ * Xilinx Spartan6 and 7 Series Slave Serial SPI Driver
  *
  * Copyright (C) 2017 DENX Software Engineering
  *
@@ -23,45 +23,107 @@
 struct xilinx_spi_conf {
 	struct spi_device *spi;
 	struct gpio_desc *prog_b;
+	struct gpio_desc *init_b;
 	struct gpio_desc *done;
 };
 
-static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr)
+static int get_done_gpio(struct fpga_manager *mgr)
 {
 	struct xilinx_spi_conf *conf = mgr->priv;
+	int ret;
+
+	ret = gpiod_get_value(conf->done);
+
+	if (ret < 0)
+		dev_err(&mgr->dev, "Error reading DONE (%d)\n", ret);
+
+	return ret;
+}
 
-	if (!gpiod_get_value(conf->done))
+static enum fpga_mgr_states xilinx_spi_state(struct fpga_manager *mgr)
+{
+	if (!get_done_gpio(mgr))
 		return FPGA_MGR_STATE_RESET;
 
 	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)) {
+			int ret = gpiod_get_value(conf->init_b);
+
+			if (ret == value)
+				return 0;
+
+			if (ret < 0) {
+				dev_err(&mgr->dev, "Error reading INIT_B (%d)\n", ret);
+				return ret;
+			}
+
+			usleep_range(100, 400);
+		}
+
+		dev_err(&mgr->dev, "Timeout waiting for INIT_B to %s\n",
+			value ? "assert" : "deassert");
+		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;
-	const size_t prog_latency_7500us = 7500;
-	const size_t prog_pulse_1us = 1;
+	int err;
 
 	if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
-		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
+		dev_err(&mgr->dev, "Partial reconfiguration not supported\n");
 		return -EINVAL;
 	}
 
 	gpiod_set_value(conf->prog_b, 1);
 
-	udelay(prog_pulse_1us); /* min is 500 ns */
+	err = wait_for_init_b(mgr, 1, 1); /* min is 500 ns */
+	if (err) {
+		gpiod_set_value(conf->prog_b, 0);
+		return err;
+	}
 
 	gpiod_set_value(conf->prog_b, 0);
 
-	if (gpiod_get_value(conf->done)) {
+	err = wait_for_init_b(mgr, 0, 0);
+	if (err)
+		return err;
+
+	if (get_done_gpio(mgr)) {
 		dev_err(&mgr->dev, "Unexpected DONE pin state...\n");
 		return -EIO;
 	}
 
 	/* program latency */
-	usleep_range(prog_latency_7500us, prog_latency_7500us + 100);
+	usleep_range(7500, 7600);
 	return 0;
 }
 
@@ -108,25 +170,46 @@ static int xilinx_spi_write_complete(struct fpga_manager *mgr,
 				     struct fpga_image_info *info)
 {
 	struct xilinx_spi_conf *conf = mgr->priv;
-	unsigned long timeout;
+	unsigned long timeout = jiffies + usecs_to_jiffies(info->config_complete_timeout_us);
+	bool expired = false;
+	int done;
 	int ret;
 
-	if (gpiod_get_value(conf->done))
-		return xilinx_spi_apply_cclk_cycles(conf);
-
-	timeout = jiffies + usecs_to_jiffies(info->config_complete_timeout_us);
+	/*
+	 * This loop is carefully written such that if the driver is
+	 * scheduled out for more than 'timeout', we still check for DONE
+	 * before giving up and we apply 8 extra CCLK cycles in all cases.
+	 */
+	while (!expired) {
+		expired = time_after(jiffies, timeout);
 
-	while (time_before(jiffies, timeout)) {
+		done = get_done_gpio(mgr);
+		if (done < 0)
+			return done;
 
 		ret = xilinx_spi_apply_cclk_cycles(conf);
 		if (ret)
 			return ret;
 
-		if (gpiod_get_value(conf->done))
-			return xilinx_spi_apply_cclk_cycles(conf);
+		if (done)
+			return 0;
+	}
+
+	if (conf->init_b) {
+		ret = gpiod_get_value(conf->init_b);
+
+		if (ret < 0) {
+			dev_err(&mgr->dev, "Error reading INIT_B (%d)\n", ret);
+			return ret;
+		}
+
+		dev_err(&mgr->dev,
+			ret ? "CRC error or invalid device\n"
+			: "Missing sync word or incomplete bitstream\n");
+	} else {
+		dev_err(&mgr->dev, "Timeout after config data transfer\n");
 	}
 
-	dev_err(&mgr->dev, "Timeout after config data transfer.\n");
 	return -ETIMEDOUT;
 }
 
@@ -150,44 +233,33 @@ static int xilinx_spi_probe(struct spi_device *spi)
 
 	/* PROGRAM_B is active low */
 	conf->prog_b = devm_gpiod_get(&spi->dev, "prog_b", GPIOD_OUT_LOW);
-	if (IS_ERR(conf->prog_b)) {
-		dev_err(&spi->dev, "Failed to get PROGRAM_B gpio: %ld\n",
-			PTR_ERR(conf->prog_b));
-		return PTR_ERR(conf->prog_b);
-	}
+	if (IS_ERR(conf->prog_b))
+		return dev_err_probe(&spi->dev, PTR_ERR(conf->prog_b),
+				     "Failed to get PROGRAM_B gpio\n");
 
-	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",
-			PTR_ERR(conf->done));
-		return PTR_ERR(conf->done);
-	}
-
-	mgr = devm_fpga_mgr_create(&spi->dev,
-				   "Xilinx Slave Serial FPGA Manager",
-				   &xilinx_spi_ops, conf);
-	if (!mgr)
-		return -ENOMEM;
-
-	spi_set_drvdata(spi, mgr);
-
-	return fpga_mgr_register(mgr);
-}
-
-static int xilinx_spi_remove(struct spi_device *spi)
-{
-	struct fpga_manager *mgr = spi_get_drvdata(spi);
+	conf->init_b = devm_gpiod_get_optional(&spi->dev, "init-b", GPIOD_IN);
+	if (IS_ERR(conf->init_b))
+		return dev_err_probe(&spi->dev, PTR_ERR(conf->init_b),
+				     "Failed to get INIT_B gpio\n");
 
-	fpga_mgr_unregister(mgr);
-
-	return 0;
+	conf->done = devm_gpiod_get(&spi->dev, "done", GPIOD_IN);
+	if (IS_ERR(conf->done))
+		return dev_err_probe(&spi->dev, PTR_ERR(conf->done),
+				     "Failed to get DONE gpio\n");
+
+	mgr = devm_fpga_mgr_register(&spi->dev,
+				     "Xilinx Slave Serial FPGA Manager",
+				     &xilinx_spi_ops, conf);
+	return PTR_ERR_OR_ZERO(mgr);
 }
 
+#ifdef CONFIG_OF
 static const struct of_device_id xlnx_spi_of_match[] = {
 	{ .compatible = "xlnx,fpga-slave-serial", },
 	{}
 };
 MODULE_DEVICE_TABLE(of, xlnx_spi_of_match);
+#endif
 
 static struct spi_driver xilinx_slave_spi_driver = {
 	.driver = {
@@ -195,7 +267,6 @@ static struct spi_driver xilinx_slave_spi_driver = {
 		.of_match_table = of_match_ptr(xlnx_spi_of_match),
 	},
 	.probe = xilinx_spi_probe,
-	.remove = xilinx_spi_remove,
 };
 
 module_spi_driver(xilinx_slave_spi_driver)