1 files changed, 242 insertions, 0 deletions
diff --git a/drivers/misc/lattice-ecp3-config.c b/drivers/misc/lattice-ecp3-config.c
new file mode 100644
index 0000000000..bac4df2e52
--- /dev/null
+++ b/drivers/misc/lattice-ecp3-config.c
@@ -0,0 +1,242 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2012 Stefan Roese <sr@denx.de>
+ */
+
+#include <linux/device.h>
+#include <linux/firmware.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/spi/spi.h>
+#include <linux/platform_device.h>
+#include <linux/delay.h>
+#include <asm/unaligned.h>
+
+#define FIRMWARE_NAME	"lattice-ecp3.bit"
+
+/*
+ * The JTAG ID's of the supported FPGA's. The ID is 32bit wide
+ * reversed as noted in the manual.
+ */
+#define ID_ECP3_17	0xc2088080
+#define ID_ECP3_35	0xc2048080
+
+/* FPGA commands */
+#define FPGA_CMD_READ_ID	0x07	/* plus 24 bits */
+#define FPGA_CMD_READ_STATUS	0x09	/* plus 24 bits */
+#define FPGA_CMD_CLEAR		0x70
+#define FPGA_CMD_REFRESH	0x71
+#define FPGA_CMD_WRITE_EN	0x4a	/* plus 2 bits */
+#define FPGA_CMD_WRITE_DIS	0x4f	/* plus 8 bits */
+#define FPGA_CMD_WRITE_INC	0x41	/* plus 0 bits */
+
+/*
+ * The status register is 32bit revered, DONE is bit 17 from the TN1222.pdf
+ * (LatticeECP3 Slave SPI Port User's Guide)
+ */
+#define FPGA_STATUS_DONE	0x00004000
+#define FPGA_STATUS_CLEARED	0x00010000
+
+#define FPGA_CLEAR_TIMEOUT	5000	/* max. 5000ms for FPGA clear */
+#define FPGA_CLEAR_MSLEEP	10
+#define FPGA_CLEAR_LOOP_COUNT	(FPGA_CLEAR_TIMEOUT / FPGA_CLEAR_MSLEEP)
+
+struct fpga_data {
+	struct completion fw_loaded;
+};
+
+struct ecp3_dev {
+	u32 jedec_id;
+	char *name;
+};
+
+static const struct ecp3_dev ecp3_dev[] = {
+	{
+		.jedec_id = ID_ECP3_17,
+		.name = "Lattice ECP3-17",
+	},
+	{
+		.jedec_id = ID_ECP3_35,
+		.name = "Lattice ECP3-35",
+	},
+};
+
+static void firmware_load(const struct firmware *fw, void *context)
+{
+	struct spi_device *spi = (struct spi_device *)context;
+	struct fpga_data *data = spi_get_drvdata(spi);
+	u8 *buffer;
+	u8 txbuf[8];
+	u8 rxbuf[8];
+	int rx_len = 8;
+	int i;
+	u32 jedec_id;
+	u32 status;
+
+	if (fw == NULL) {
+		dev_err(&spi->dev, "Cannot load firmware, aborting\n");
+		goto out;
+	}
+
+	if (fw->size == 0) {
+		dev_err(&spi->dev, "Error: Firmware size is 0!\n");
+		goto out;
+	}
+
+	/* Fill dummy data (24 stuffing bits for commands) */
+	txbuf[1] = 0x00;
+	txbuf[2] = 0x00;
+	txbuf[3] = 0x00;
+
+	/* Trying to speak with the FPGA via SPI... */
+	txbuf[0] = FPGA_CMD_READ_ID;
+	spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
+	jedec_id = get_unaligned_be32(&rxbuf[4]);
+	dev_dbg(&spi->dev, "FPGA JTAG ID=%08x\n", jedec_id);
+
+	for (i = 0; i < ARRAY_SIZE(ecp3_dev); i++) {
+		if (jedec_id == ecp3_dev[i].jedec_id)
+			break;
+	}
+	if (i == ARRAY_SIZE(ecp3_dev)) {
+		dev_err(&spi->dev,
+			"Error: No supported FPGA detected (JEDEC_ID=%08x)!\n",
+			jedec_id);
+		goto out;
+	}
+
+	dev_info(&spi->dev, "FPGA %s detected\n", ecp3_dev[i].name);
+
+	txbuf[0] = FPGA_CMD_READ_STATUS;
+	spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
+	status = get_unaligned_be32(&rxbuf[4]);
+	dev_dbg(&spi->dev, "FPGA Status=%08x\n", status);
+
+	buffer = kzalloc(fw->size + 8, GFP_KERNEL);
+	if (!buffer) {
+		dev_err(&spi->dev, "Error: Can't allocate memory!\n");
+		goto out;
+	}
+
+	/*
+	 * Insert WRITE_INC command into stream (one SPI frame)
+	 */
+	buffer[0] = FPGA_CMD_WRITE_INC;
+	buffer[1] = 0xff;
+	buffer[2] = 0xff;
+	buffer[3] = 0xff;
+	memcpy(buffer + 4, fw->data, fw->size);
+
+	txbuf[0] = FPGA_CMD_REFRESH;
+	spi_write(spi, txbuf, 4);
+
+	txbuf[0] = FPGA_CMD_WRITE_EN;
+	spi_write(spi, txbuf, 4);
+
+	txbuf[0] = FPGA_CMD_CLEAR;
+	spi_write(spi, txbuf, 4);
+
+	/*
+	 * Wait for FPGA memory to become cleared
+	 */
+	for (i = 0; i < FPGA_CLEAR_LOOP_COUNT; i++) {
+		txbuf[0] = FPGA_CMD_READ_STATUS;
+		spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
+		status = get_unaligned_be32(&rxbuf[4]);
+		if (status == FPGA_STATUS_CLEARED)
+			break;
+
+		msleep(FPGA_CLEAR_MSLEEP);
+	}
+
+	if (i == FPGA_CLEAR_LOOP_COUNT) {
+		dev_err(&spi->dev,
+			"Error: Timeout waiting for FPGA to clear (status=%08x)!\n",
+			status);
+		kfree(buffer);
+		goto out;
+	}
+
+	dev_info(&spi->dev, "Configuring the FPGA...\n");
+	spi_write(spi, buffer, fw->size + 8);
+
+	txbuf[0] = FPGA_CMD_WRITE_DIS;
+	spi_write(spi, txbuf, 4);
+
+	txbuf[0] = FPGA_CMD_READ_STATUS;
+	spi_write_then_read(spi, txbuf, 8, rxbuf, rx_len);
+	status = get_unaligned_be32(&rxbuf[4]);
+	dev_dbg(&spi->dev, "FPGA Status=%08x\n", status);
+
+	/* Check result */
+	if (status & FPGA_STATUS_DONE)
+		dev_info(&spi->dev, "FPGA successfully configured!\n");
+	else
+		dev_info(&spi->dev, "FPGA not configured (DONE not set)\n");
+
+	/*
+	 * Don't forget to release the firmware again
+	 */
+	release_firmware(fw);
+
+	kfree(buffer);
+out:
+	complete(&data->fw_loaded);
+}
+
+static int lattice_ecp3_probe(struct spi_device *spi)
+{
+	struct fpga_data *data;
+	int err;
+
+	data = devm_kzalloc(&spi->dev, sizeof(*data), GFP_KERNEL);
+	if (!data) {
+		dev_err(&spi->dev, "Memory allocation for fpga_data failed\n");
+		return -ENOMEM;
+	}
+	spi_set_drvdata(spi, data);
+
+	init_completion(&data->fw_loaded);
+	err = request_firmware_nowait(THIS_MODULE, FW_ACTION_UEVENT,
+				      FIRMWARE_NAME, &spi->dev,
+				      GFP_KERNEL, spi, firmware_load);
+	if (err) {
+		dev_err(&spi->dev, "Firmware loading failed with %d!\n", err);
+		return err;
+	}
+
+	dev_info(&spi->dev, "FPGA bitstream configuration driver registered\n");
+
+	return 0;
+}
+
+static void lattice_ecp3_remove(struct spi_device *spi)
+{
+	struct fpga_data *data = spi_get_drvdata(spi);
+
+	wait_for_completion(&data->fw_loaded);
+}
+
+static const struct spi_device_id lattice_ecp3_id[] = {
+	{ "ecp3-17", 0 },
+	{ "ecp3-35", 0 },
+	{ }
+};
+MODULE_DEVICE_TABLE(spi, lattice_ecp3_id);
+
+static struct spi_driver lattice_ecp3_driver = {
+	.driver = {
+		.name = "lattice-ecp3",
+	},
+	.probe = lattice_ecp3_probe,
+	.remove = lattice_ecp3_remove,
+	.id_table = lattice_ecp3_id,
+};
+
+module_spi_driver(lattice_ecp3_driver);
+
+MODULE_AUTHOR("Stefan Roese <sr@denx.de>");
+MODULE_DESCRIPTION("Lattice ECP3 FPGA configuration via SPI");
+MODULE_LICENSE("GPL");
+MODULE_FIRMWARE(FIRMWARE_NAME);