[PATCH v8 1/2] fpga: lattice-sysconfig-spi: add Lattice sysCONFIG FPGA manager

[Ivan Bornyakov]

Add support to the FPGA manager for programming Lattice ECP5 and MachXO2
FPGAs over slave SPI sysCONFIG interface.

Signed-off-by: Ivan Bornyakov <i.bornyakov@xxxxxxxxxxx>
---
 drivers/fpga/Kconfig                 |   7 +
 drivers/fpga/Makefile                |   1 +
 drivers/fpga/lattice-sysconfig-spi.c | 630 +++++++++++++++++++++++++++
 3 files changed, 638 insertions(+)
 create mode 100644 drivers/fpga/lattice-sysconfig-spi.c

diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index 6c416955da53..991d9d976dca 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -263,4 +263,11 @@ config FPGA_MGR_MICROCHIP_SPI
 	  programming over slave SPI interface with .dat formatted
 	  bitstream image.
 
+config FPGA_MGR_LATTICE_SPI
+	tristate "Lattice sysCONFIG SPI FPGA manager"
+	depends on SPI
+	help
+	  FPGA manager driver support for Lattice FPGAs programming over slave
+	  SPI sysCONFIG interface.
+
 endif # FPGA
diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
index 42ae8b58abce..115dba916024 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_FPGA_MGR_ZYNQ_FPGA)	+= zynq-fpga.o
 obj-$(CONFIG_FPGA_MGR_ZYNQMP_FPGA)	+= zynqmp-fpga.o
 obj-$(CONFIG_FPGA_MGR_VERSAL_FPGA)	+= versal-fpga.o
 obj-$(CONFIG_FPGA_MGR_MICROCHIP_SPI)	+= microchip-spi.o
+obj-$(CONFIG_FPGA_MGR_LATTICE_SPI)	+= lattice-sysconfig-spi.o
 obj-$(CONFIG_ALTERA_PR_IP_CORE)		+= altera-pr-ip-core.o
 obj-$(CONFIG_ALTERA_PR_IP_CORE_PLAT)	+= altera-pr-ip-core-plat.o
 
diff --git a/drivers/fpga/lattice-sysconfig-spi.c b/drivers/fpga/lattice-sysconfig-spi.c
new file mode 100644
index 000000000000..145b5b27b88d
--- /dev/null
+++ b/drivers/fpga/lattice-sysconfig-spi.c
@@ -0,0 +1,630 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Lattice FPGA programming over slave SPI sysCONFIG interface.
+ */
+
+#include <linux/delay.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/of_device.h>
+#include <linux/spi/spi.h>
+
+#define	SYSCONFIG_ISC_ENABLE		{0xC6, 0x00, 0x00, 0x00}
+#define	SYSCONFIG_ISC_DISABLE		{0x26, 0x00, 0x00, 0x00}
+#define	SYSCONFIG_ISC_ERASE		{0x0E, 0x00, 0x00, 0x00}
+#define	SYSCONFIG_ISC_PROGRAM_DONE	{0x5E, 0x00, 0x00, 0x00}
+#define	SYSCONFIG_LSC_READ_STATUS	{0x3C, 0x00, 0x00, 0x00}
+#define	SYSCONFIG_LSC_CHECK_BUSY	{0xF0, 0x00, 0x00, 0x00}
+#define	SYSCONFIG_LSC_REFRESH		{0x79, 0x00, 0x00, 0x00}
+#define	SYSCONFIG_LSC_INIT_ADDR		{0x46, 0x00, 0x00, 0x00}
+#define	SYSCONFIG_LSC_BITSTREAM_BURST	{0x7a, 0x00, 0x00, 0x00}
+#define	SYSCONFIG_LSC_PROG_INCR_NV	{0x70, 0x00, 0x00, 0x01}
+
+#define	SYSCONFIG_STATUS_DONE		BIT(8)
+#define	SYSCONFIG_STATUS_BUSY		BIT(12)
+#define	SYSCONFIG_STATUS_FAIL		BIT(13)
+#define	SYSCONFIG_STATUS_ERR		(BIT(23) | BIT(24) | BIT(25))
+
+#define	SYSCONFIG_POLL_RETRIES		100000
+
+#define	ECP5_SPI_MAX_SPEED_HZ		60000000
+#define	ECP5_ISC_ERASE_OPERAND		0x01
+
+#define	MACHXO2_SPI_MAX_SPEED_HZ	66000000
+#define	MACHXO2_PAGE_SIZE		16
+#define	MACHXO2_ISC_ENABLE_OPERAND	0x08
+#define	MACHXO2_ISC_ERASE_OPERAND	0x04
+
+struct sysconfig_priv {
+	struct gpio_desc *program;
+	struct gpio_desc *init;
+	struct gpio_desc *done;
+	struct spi_device *spi;
+	u8 isc_enable_operand;
+	u8 isc_erase_operand;
+};
+
+static int sysconfig_poll_busy(struct sysconfig_priv *data)
+{
+	const u8 lsc_check_busy[] = SYSCONFIG_LSC_CHECK_BUSY;
+	int ret, retries = SYSCONFIG_POLL_RETRIES;
+	u8 busy;
+
+	while (retries--) {
+		ret = spi_write_then_read(data->spi,
+					  lsc_check_busy, sizeof(lsc_check_busy),
+					  &busy, sizeof(busy));
+		if (ret)
+			return ret;
+
+		if (!busy)
+			return 0;
+
+		usleep_range(50, 100);
+	}
+
+	return -EBUSY;
+}
+
+static int sysconfig_read_status(struct sysconfig_priv *data, u32 *status)
+{
+	const u8 lsc_read_status[] = SYSCONFIG_LSC_READ_STATUS;
+	__be32 device_status;
+	int ret;
+
+	ret = spi_write_then_read(data->spi,
+				  lsc_read_status, sizeof(lsc_read_status),
+				  &device_status, sizeof(device_status));
+	if (ret)
+		return ret;
+
+	*status = be32_to_cpu(device_status);
+
+	return 0;
+}
+
+static int sysconfig_poll_status(struct sysconfig_priv *data, u32 *status)
+{
+	int ret;
+
+	ret = sysconfig_poll_busy(data);
+	if (ret)
+		return ret;
+
+	return sysconfig_read_status(data, status);
+}
+
+static int sysconfig_poll_gpio(struct gpio_desc *gpio, bool is_active)
+{
+	int value, retries = SYSCONFIG_POLL_RETRIES;
+
+	while (retries--) {
+		value = gpiod_get_value(gpio);
+		if (value < 0)
+			return value;
+
+		if ((!is_active && !value) || (is_active && value))
+			return 0;
+
+		ndelay(10);
+	}
+
+	return -ETIMEDOUT;
+}
+
+static int sysconfig_refresh(struct sysconfig_priv *data)
+{
+	static const u8 lsc_refresh[] = SYSCONFIG_LSC_REFRESH;
+	int ret;
+
+	ret = spi_write(data->spi, lsc_refresh, sizeof(lsc_refresh));
+	if (ret)
+		return ret;
+
+	usleep_range(4000, 8000);
+
+	return 0;
+}
+
+static int sysconfig_isc_enable(struct sysconfig_priv *data)
+{
+	u8 isc_enable[] = SYSCONFIG_ISC_ENABLE;
+	u32 status;
+	int ret;
+
+	isc_enable[1] = data->isc_enable_operand;
+
+	ret = spi_write(data->spi, isc_enable, sizeof(isc_enable));
+	if (ret)
+		return ret;
+
+	ret = sysconfig_poll_status(data, &status);
+	if (ret || (status & SYSCONFIG_STATUS_FAIL))
+		return ret ? : -EFAULT;
+
+	return 0;
+}
+
+static int sysconfig_isc_erase(struct sysconfig_priv *data)
+{
+	u8 isc_erase[] = SYSCONFIG_ISC_ERASE;
+	u32 status;
+	int ret;
+
+	isc_erase[1] = data->isc_erase_operand;
+
+	ret = spi_write(data->spi, isc_erase, sizeof(isc_erase));
+	if (ret)
+		return ret;
+
+	ret = sysconfig_poll_status(data, &status);
+	if (ret || (status & SYSCONFIG_STATUS_FAIL))
+		return ret ? : -EFAULT;
+
+	return 0;
+}
+
+static int sysconfig_isc_init(struct sysconfig_priv *data)
+{
+	int ret;
+
+	ret = sysconfig_isc_enable(data);
+	if (ret)
+		return ret;
+
+	return sysconfig_isc_erase(data);
+}
+
+static int sysconfig_lsc_init_addr(struct sysconfig_priv *data)
+{
+	const u8 lsc_init_addr[] = SYSCONFIG_LSC_INIT_ADDR;
+
+	return spi_write(data->spi, lsc_init_addr, sizeof(lsc_init_addr));
+}
+
+static int sysconfig_lsc_bitstream_burst(struct sysconfig_priv *data)
+{
+	const u8 lsc_bitstream_burst[] = SYSCONFIG_LSC_BITSTREAM_BURST;
+	struct spi_transfer xfer = {
+		.tx_buf = lsc_bitstream_burst,
+		.len = sizeof(lsc_bitstream_burst),
+		.cs_change = 1,
+	};
+	struct spi_message msg;
+
+	spi_message_init_with_transfers(&msg, &xfer, 1);
+
+	return spi_sync_locked(data->spi, &msg);
+}
+
+static int sysconfig_isc_prog_done(struct sysconfig_priv *data)
+{
+	const u8 isc_prog_done[] = SYSCONFIG_ISC_PROGRAM_DONE;
+	u32 status;
+	int ret;
+
+	ret = spi_write(data->spi, isc_prog_done, sizeof(isc_prog_done));
+	if (ret)
+		return ret;
+
+	ret = sysconfig_poll_status(data, &status);
+	if (ret)
+		return ret;
+
+	if (status & SYSCONFIG_STATUS_DONE)
+		return 0;
+
+	return -EFAULT;
+}
+
+static int sysconfig_isc_disable(struct sysconfig_priv *data)
+{
+	const u8 isc_disable[] = SYSCONFIG_ISC_DISABLE;
+
+	return spi_write(data->spi, isc_disable, sizeof(isc_disable));
+}
+
+static enum fpga_mgr_states ecp5_ops_state(struct fpga_manager *mgr)
+{
+	struct sysconfig_priv *priv = mgr->priv;
+
+	return (gpiod_get_value(priv->done) > 0) ? FPGA_MGR_STATE_OPERATING :
+						   FPGA_MGR_STATE_UNKNOWN;
+}
+
+static int ecp5_ops_write_init(struct fpga_manager *mgr,
+			       struct fpga_image_info *info,
+			       const char *buf, size_t count)
+{
+	struct sysconfig_priv *priv = mgr->priv;
+	struct spi_device *spi = priv->spi;
+	struct device *dev = &mgr->dev;
+	struct gpio_desc *program;
+	struct gpio_desc *init;
+	struct gpio_desc *done;
+	int ret;
+
+	if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
+		dev_err(dev, "Partial reconfiguration is not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	program = priv->program;
+	init = priv->init;
+	done = priv->done;
+
+	/* Enter init mode */
+	gpiod_set_value(program, 1);
+
+	ret = sysconfig_poll_gpio(init, true);
+	if (!ret)
+		ret = sysconfig_poll_gpio(done, false);
+
+	if (ret) {
+		dev_err(dev, "Failed to go to init mode\n");
+		return ret;
+	}
+
+	/* Enter program mode */
+	gpiod_set_value(program, 0);
+
+	ret = sysconfig_poll_gpio(init, false);
+	if (ret) {
+		dev_err(dev, "Failed to go to program mode\n");
+		return ret;
+	}
+
+	/* Enter ISC mode */
+	ret = sysconfig_isc_init(priv);
+	if (ret) {
+		dev_err(dev, "Failed to go to ISC mode\n");
+		return ret;
+	}
+
+	/* Initialize the Address Shift Register */
+	ret = sysconfig_lsc_init_addr(priv);
+	if (ret) {
+		dev_err(dev,
+			"Failed to initialize the Address Shift Register\n");
+		return ret;
+	}
+
+	/*
+	 * Lock SPI bus for exclusive usage until FPGA programming is done.
+	 * SPI bus will be released in ecp5_ops_write_complete() or on error.
+	 */
+	spi_bus_lock(spi->controller);
+
+	/* Prepare for bitstream burst write */
+	ret = sysconfig_lsc_bitstream_burst(priv);
+	if (ret) {
+		dev_err(dev, "Failed to prepare for bitstream burst write\n");
+		spi_bus_unlock(spi->controller);
+	}
+
+	return ret;
+}
+
+static int ecp5_ops_write(struct fpga_manager *mgr, const char *buf, size_t count)
+{
+	struct sysconfig_priv *priv = mgr->priv;
+	struct spi_device *spi = priv->spi;
+	struct spi_transfer xfer = {
+		.tx_buf = buf,
+		.len = count,
+		.cs_change = 1,
+	};
+	struct spi_message msg;
+	int ret;
+
+	spi_message_init_with_transfers(&msg, &xfer, 1);
+	ret = spi_sync_locked(spi, &msg);
+	if (ret)
+		spi_bus_unlock(spi->controller);
+
+	return ret;
+}
+
+static int ecp5_ops_write_complete(struct fpga_manager *mgr,
+				   struct fpga_image_info *info)
+{
+	struct sysconfig_priv *priv = mgr->priv;
+	struct spi_device *spi = priv->spi;
+	struct device *dev = &mgr->dev;
+	int ret;
+
+	/* Bitstream burst write is done, release SPI bus */
+	spi_bus_unlock(spi->controller);
+
+	/* Toggle CS and wait for bitstream write to finish */
+	ret = spi_write(spi, NULL, 0);
+	if (!ret)
+		ret = sysconfig_poll_busy(priv);
+
+	if (ret) {
+		dev_err(dev, "Error while waiting bitstream write to finish\n");
+		return ret;
+	}
+
+	/* Exit ISC mode */
+	ret = sysconfig_isc_disable(priv);
+	if (!ret)
+		ret = sysconfig_poll_gpio(priv->done, true);
+
+	if (ret)
+		dev_err(dev, "Failed to finish ISC\n");
+
+	return ret;
+}
+
+static const struct fpga_manager_ops ecp5_fpga_ops = {
+	.state = ecp5_ops_state,
+	.write_init = ecp5_ops_write_init,
+	.write = ecp5_ops_write,
+	.write_complete = ecp5_ops_write_complete,
+};
+
+static int ecp5_probe(struct sysconfig_priv *priv)
+{
+	struct spi_device *spi = priv->spi;
+	struct device *dev = &spi->dev;
+	struct fpga_manager *mgr;
+	int ret;
+
+	if (spi->max_speed_hz > ECP5_SPI_MAX_SPEED_HZ) {
+		dev_err(dev, "SPI speed %u is too high, maximum speed is %u\n",
+			spi->max_speed_hz, ECP5_SPI_MAX_SPEED_HZ);
+		return -EINVAL;
+	}
+
+	priv->isc_erase_operand = ECP5_ISC_ERASE_OPERAND;
+
+	priv->done = devm_gpiod_get(dev, "done", GPIOD_IN);
+	if (IS_ERR(priv->done)) {
+		ret = PTR_ERR(priv->done);
+		dev_err(dev, "Failed to get DONE GPIO: %d\n", ret);
+		return ret;
+	}
+
+	priv->init = devm_gpiod_get(dev, "init", GPIOD_IN);
+	if (IS_ERR(priv->init)) {
+		ret = PTR_ERR(priv->init);
+		dev_err(dev, "Failed to get INIT GPIO: %d\n", ret);
+		return ret;
+	}
+
+	priv->program = devm_gpiod_get(dev, "program", GPIOD_OUT_LOW);
+	if (IS_ERR(priv->program)) {
+		ret = PTR_ERR(priv->program);
+		dev_err(dev, "Failed to get PROGRAM GPIO: %d\n", ret);
+		return ret;
+	}
+
+	mgr = devm_fpga_mgr_register(dev, "Lattice ECP5 SPI FPGA Manager",
+				     &ecp5_fpga_ops, priv);
+
+	return PTR_ERR_OR_ZERO(mgr);
+}
+
+static enum fpga_mgr_states machxo2_ops_state(struct fpga_manager *mgr)
+{
+	struct sysconfig_priv *priv = mgr->priv;
+	u32 status;
+	int ret;
+
+	ret = sysconfig_read_status(priv, &status);
+	if (ret || !(status & SYSCONFIG_STATUS_DONE))
+		return FPGA_MGR_STATE_UNKNOWN;
+
+	return FPGA_MGR_STATE_OPERATING;
+}
+
+static int machxo2_ops_write_init(struct fpga_manager *mgr,
+				  struct fpga_image_info *info,
+				  const char *buf, size_t count)
+{
+	struct sysconfig_priv *priv = mgr->priv;
+	struct device *dev = &mgr->dev;
+	int ret;
+
+	if (info->flags & FPGA_MGR_PARTIAL_RECONFIG) {
+		dev_err(dev, "Partial reconfiguration is not supported\n");
+		return -EOPNOTSUPP;
+	}
+
+	/* Enter ISC mode */
+	ret = sysconfig_isc_init(priv);
+	if (ret) {
+		dev_err(dev, "Failed to go to ISC mode\n");
+		return ret;
+	}
+
+	/* Initialize the Address Shift Register */
+	ret = sysconfig_lsc_init_addr(priv);
+	if (ret)
+		dev_err(dev,
+			"Failed to initialize the Address Shift Register\n");
+
+	return ret;
+}
+
+static int machxo2_ops_write(struct fpga_manager *mgr, const char *buf, size_t count)
+{
+	const u8 lsc_progincr[] = SYSCONFIG_LSC_PROG_INCR_NV;
+	struct sysconfig_priv *priv = mgr->priv;
+	struct device *dev = &mgr->dev;
+	struct spi_transfer xfers[2] = {
+		{
+			.tx_buf = lsc_progincr,
+			.len = sizeof(lsc_progincr),
+		}, {
+			.len = MACHXO2_PAGE_SIZE,
+		},
+	};
+	size_t i;
+	int ret;
+
+	if (count % MACHXO2_PAGE_SIZE) {
+		dev_err(dev, "Malformed payload.\n");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < count; i += MACHXO2_PAGE_SIZE) {
+		xfers[1].tx_buf = buf + i;
+
+		ret = spi_sync_transfer(priv->spi, xfers, 2);
+		if (!ret)
+			ret = sysconfig_poll_busy(priv);
+
+		if (ret) {
+			dev_err(dev, "Failed to write frame %zu of %zu\n",
+				i / MACHXO2_PAGE_SIZE, count / MACHXO2_PAGE_SIZE);
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void machxo2_cleanup(struct sysconfig_priv *data)
+{
+	sysconfig_isc_erase(data);
+	sysconfig_refresh(data);
+}
+
+static int machxo2_ops_write_complete(struct fpga_manager *mgr,
+				      struct fpga_image_info *info)
+{
+	int ret, retries = SYSCONFIG_POLL_RETRIES;
+	struct sysconfig_priv *priv = mgr->priv;
+	struct device *dev = &mgr->dev;
+	u32 status;
+
+	ret = sysconfig_isc_prog_done(priv);
+	if (ret) {
+		dev_err(dev, "Failed to enable Self-Download Mode\n");
+		goto fail;
+	}
+
+	ret = sysconfig_isc_disable(priv);
+	if (ret) {
+		dev_err(dev, "Failed to disable Configuration Interface\n");
+		goto fail;
+	}
+
+	while (retries--) {
+		ret = sysconfig_refresh(priv);
+		if (!ret)
+			ret = sysconfig_read_status(priv, &status);
+
+		if (ret) {
+			dev_err(dev, "Failed to refresh\n");
+			break;
+		}
+
+		if (status & SYSCONFIG_STATUS_DONE &&
+		    !(status & SYSCONFIG_STATUS_BUSY) &&
+		    !(status & SYSCONFIG_STATUS_ERR))
+			return 0;
+	}
+
+fail:
+	machxo2_cleanup(priv);
+
+	return -EFAULT;
+}
+
+static const struct fpga_manager_ops machxo2_fpga_ops = {
+	.state = machxo2_ops_state,
+	.write_init = machxo2_ops_write_init,
+	.write = machxo2_ops_write,
+	.write_complete = machxo2_ops_write_complete,
+};
+
+static int machxo2_probe(struct sysconfig_priv *priv)
+{
+	struct spi_device *spi = priv->spi;
+	struct device *dev = &spi->dev;
+	struct fpga_manager *mgr;
+
+	if (spi->max_speed_hz > MACHXO2_SPI_MAX_SPEED_HZ) {
+		dev_err(dev, "SPI speed %u is too high, maximum speed is %u\n",
+			spi->max_speed_hz, MACHXO2_SPI_MAX_SPEED_HZ);
+		return -EINVAL;
+	}
+
+	priv->isc_enable_operand = MACHXO2_ISC_ENABLE_OPERAND;
+	priv->isc_erase_operand = MACHXO2_ISC_ERASE_OPERAND;
+
+	mgr = devm_fpga_mgr_register(dev, "Lattice MachXO2 SPI FPGA Manager",
+				     &machxo2_fpga_ops, priv);
+
+	return PTR_ERR_OR_ZERO(mgr);
+}
+
+typedef int (*lattice_fpga_probe_func)(struct sysconfig_priv *);
+
+static int sysconfig_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *dev_id;
+	lattice_fpga_probe_func probe_func;
+	struct device *dev = &spi->dev;
+	struct sysconfig_priv *priv;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	priv->spi = spi;
+
+	probe_func = of_device_get_match_data(&spi->dev);
+	if (!probe_func) {
+		dev_id = spi_get_device_id(spi);
+		if (!dev_id)
+			return -ENODEV;
+
+		probe_func = (lattice_fpga_probe_func)dev_id->driver_data;
+	}
+
+	if (!probe_func)
+		return -EINVAL;
+
+	return probe_func(priv);
+}
+
+static const struct spi_device_id sysconfig_spi_ids[] = {
+	{
+		.name = "ecp5-fpga-mgr",
+		.driver_data = (kernel_ulong_t)ecp5_probe,
+	}, {
+		.name = "machxo2-fpga-mgr",
+		.driver_data = (kernel_ulong_t)machxo2_probe,
+	}, {},
+};
+MODULE_DEVICE_TABLE(spi, sysconfig_spi_ids);
+
+#if IS_ENABLED(CONFIG_OF)
+static const struct of_device_id sysconfig_of_ids[] = {
+	{
+		.compatible = "lattice,ecp5-fpga-mgr",
+		.data = ecp5_probe,
+	}, {
+		.compatible = "lattice,machxo2-fpga-mgr",
+		.data = machxo2_probe
+	}, {},
+};
+MODULE_DEVICE_TABLE(of, sysconfig_of_ids);
+#endif /* IS_ENABLED(CONFIG_OF) */
+
+static struct spi_driver lattice_sysconfig_driver = {
+	.probe = sysconfig_probe,
+	.id_table = sysconfig_spi_ids,
+	.driver = {
+		.name = "lattice_sysconfig_spi_fpga_mgr",
+		.of_match_table = of_match_ptr(sysconfig_of_ids),
+	},
+};
+
+module_spi_driver(lattice_sysconfig_driver);
+
+MODULE_DESCRIPTION("Lattice sysCONFIG Slave SPI FPGA Manager");
+MODULE_LICENSE("GPL");
-- 
2.37.2