[PATCH v19 1/2] fpga: lattice-sysconfig-spi: add Lattice sysCONFIG FPGA manager

[Ivan Bornyakov]

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

sysCONFIG interface core functionality is separate from both ECP5 and
SPI specifics, so support for other FPGAs with different port types can
be added in the future.

Signed-off-by: Ivan Bornyakov <i.bornyakov@xxxxxxxxxxx>
---
 drivers/fpga/Kconfig                 |  11 +
 drivers/fpga/Makefile                |   2 +
 drivers/fpga/lattice-sysconfig-spi.c | 154 +++++++++++
 drivers/fpga/lattice-sysconfig.c     | 397 +++++++++++++++++++++++++++
 drivers/fpga/lattice-sysconfig.h     |  39 +++
 5 files changed, 603 insertions(+)
 create mode 100644 drivers/fpga/lattice-sysconfig-spi.c
 create mode 100644 drivers/fpga/lattice-sysconfig.c
 create mode 100644 drivers/fpga/lattice-sysconfig.h

diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
index 6c416955da53..d1a8107fdcb3 100644
--- a/drivers/fpga/Kconfig
+++ b/drivers/fpga/Kconfig
@@ -263,4 +263,15 @@ config FPGA_MGR_MICROCHIP_SPI
 	  programming over slave SPI interface with .dat formatted
 	  bitstream image.
 
+config FPGA_MGR_LATTICE_SYSCONFIG
+	tristate
+
+config FPGA_MGR_LATTICE_SYSCONFIG_SPI
+	tristate "Lattice sysCONFIG SPI FPGA manager"
+	depends on SPI
+	select FPGA_MGR_LATTICE_SYSCONFIG
+	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..72e554b4d2f7 100644
--- a/drivers/fpga/Makefile
+++ b/drivers/fpga/Makefile
@@ -20,6 +20,8 @@ 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-$(CONFIG_FPGA_MGR_LATTICE_SYSCONFIG)	+= lattice-sysconfig.o
+obj-$(CONFIG_FPGA_MGR_LATTICE_SYSCONFIG_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..9dd9b3c7b42f
--- /dev/null
+++ b/drivers/fpga/lattice-sysconfig-spi.c
@@ -0,0 +1,154 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Lattice FPGA programming over slave SPI sysCONFIG interface.
+ */
+
+#include <linux/spi/spi.h>
+
+#include "lattice-sysconfig.h"
+
+static const u32 ecp5_spi_max_speed_hz = 60000000;
+
+static int sysconfig_spi_cmd_transfer(struct sysconfig_priv *priv,
+				      const void *tx_buf, size_t tx_len,
+				      void *rx_buf, size_t rx_len)
+{
+	struct spi_device *spi = to_spi_device(priv->dev);
+
+	return spi_write_then_read(spi, tx_buf, tx_len, rx_buf, rx_len);
+}
+
+static int sysconfig_spi_bitstream_burst_init(struct sysconfig_priv *priv)
+{
+	const u8 lsc_bitstream_burst[] = SYSCONFIG_LSC_BITSTREAM_BURST;
+	struct spi_device *spi = to_spi_device(priv->dev);
+	struct spi_transfer xfer = {};
+	struct spi_message msg;
+	size_t buf_len;
+	void *buf;
+	int ret;
+
+	buf_len = sizeof(lsc_bitstream_burst);
+
+	buf = kmalloc(buf_len, GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	memcpy(buf, lsc_bitstream_burst, buf_len);
+
+	xfer.len = buf_len;
+	xfer.tx_buf = buf;
+	xfer.cs_change = 1;
+
+	spi_message_init_with_transfers(&msg, &xfer, 1);
+
+	/*
+	 * Lock SPI bus for exclusive usage until FPGA programming is done.
+	 * SPI bus will be released in sysconfig_spi_bitstream_burst_complete().
+	 */
+	spi_bus_lock(spi->controller);
+
+	ret = spi_sync_locked(spi, &msg);
+	if (ret)
+		spi_bus_unlock(spi->controller);
+
+	kfree(buf);
+
+	return ret;
+}
+
+static int sysconfig_spi_bitstream_burst_write(struct sysconfig_priv *priv,
+					       const char *buf, size_t len)
+{
+	struct spi_device *spi = to_spi_device(priv->dev);
+	struct spi_transfer xfer = {
+		.tx_buf = buf,
+		.len = len,
+		.cs_change = 1,
+	};
+	struct spi_message msg;
+
+	spi_message_init_with_transfers(&msg, &xfer, 1);
+
+	return spi_sync_locked(spi, &msg);
+}
+
+static int sysconfig_spi_bitstream_burst_complete(struct sysconfig_priv *priv)
+{
+	struct spi_device *spi = to_spi_device(priv->dev);
+
+	/* Bitstream burst write is done, release SPI bus */
+	spi_bus_unlock(spi->controller);
+
+	/* Toggle CS to finish bitstream write */
+	return spi_write(spi, NULL, 0);
+}
+
+static int sysconfig_spi_probe(struct spi_device *spi)
+{
+	const struct spi_device_id *dev_id;
+	struct device *dev = &spi->dev;
+	struct sysconfig_priv *priv;
+	const u32 *spi_max_speed;
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	spi_max_speed = device_get_match_data(dev);
+	if (!spi_max_speed) {
+		dev_id = spi_get_device_id(spi);
+		if (!dev_id)
+			return -ENODEV;
+
+		spi_max_speed = (const u32 *)dev_id->driver_data;
+	}
+
+	if (!spi_max_speed)
+		return -EINVAL;
+
+	if (spi->max_speed_hz > *spi_max_speed) {
+		dev_err(dev, "SPI speed %u is too high, maximum speed is %u\n",
+			spi->max_speed_hz, *spi_max_speed);
+		return -EINVAL;
+	}
+
+	priv->dev = dev;
+	priv->command_transfer = sysconfig_spi_cmd_transfer;
+	priv->bitstream_burst_write_init = sysconfig_spi_bitstream_burst_init;
+	priv->bitstream_burst_write = sysconfig_spi_bitstream_burst_write;
+	priv->bitstream_burst_write_complete = sysconfig_spi_bitstream_burst_complete;
+
+	return sysconfig_probe(priv);
+}
+
+static const struct spi_device_id sysconfig_spi_ids[] = {
+	{
+		.name = "sysconfig-ecp5",
+		.driver_data = (kernel_ulong_t)&ecp5_spi_max_speed_hz,
+	}, {},
+};
+MODULE_DEVICE_TABLE(spi, sysconfig_spi_ids);
+
+#if IS_ENABLED(CONFIG_OF)
+static const struct of_device_id sysconfig_of_ids[] = {
+	{
+		.compatible = "lattice,sysconfig-ecp5",
+		.data = &ecp5_spi_max_speed_hz,
+	}, {},
+};
+MODULE_DEVICE_TABLE(of, sysconfig_of_ids);
+#endif /* IS_ENABLED(CONFIG_OF) */
+
+static struct spi_driver lattice_sysconfig_driver = {
+	.probe = sysconfig_spi_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");
diff --git a/drivers/fpga/lattice-sysconfig.c b/drivers/fpga/lattice-sysconfig.c
new file mode 100644
index 000000000000..ba51a60f672f
--- /dev/null
+++ b/drivers/fpga/lattice-sysconfig.c
@@ -0,0 +1,397 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Lattice FPGA sysCONFIG interface functions independent of port type.
+ */
+
+#include <linux/delay.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/gpio/consumer.h>
+#include <linux/iopoll.h>
+
+#include "lattice-sysconfig.h"
+
+static int sysconfig_cmd_write(struct sysconfig_priv *priv, const void *buf,
+			       size_t buf_len)
+{
+	return priv->command_transfer(priv, buf, buf_len, NULL, 0);
+}
+
+static int sysconfig_cmd_read(struct sysconfig_priv *priv, const void *tx_buf,
+			      size_t tx_len, void *rx_buf, size_t rx_len)
+{
+	return priv->command_transfer(priv, tx_buf, tx_len, rx_buf, rx_len);
+}
+
+static int sysconfig_read_busy(struct sysconfig_priv *priv)
+{
+	const u8 lsc_check_busy[] = SYSCONFIG_LSC_CHECK_BUSY;
+	u8 busy;
+	int ret;
+
+	ret = sysconfig_cmd_read(priv, lsc_check_busy, sizeof(lsc_check_busy),
+				 &busy, sizeof(busy));
+
+	return ret ? : busy;
+}
+
+static int sysconfig_poll_busy(struct sysconfig_priv *priv)
+{
+	int ret, busy;
+
+	ret = read_poll_timeout(sysconfig_read_busy, busy, busy <= 0,
+				SYSCONFIG_POLL_INTERVAL_US,
+				SYSCONFIG_POLL_BUSY_TIMEOUT_US, false, priv);
+
+	return ret ? : busy;
+}
+
+static int sysconfig_read_status(struct sysconfig_priv *priv, u32 *status)
+{
+	const u8 lsc_read_status[] = SYSCONFIG_LSC_READ_STATUS;
+	__be32 device_status;
+	int ret;
+
+	ret = sysconfig_cmd_read(priv, 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 *priv, u32 *status)
+{
+	int ret = sysconfig_poll_busy(priv);
+
+	if (ret)
+		return ret;
+
+	return sysconfig_read_status(priv, status);
+}
+
+static int sysconfig_poll_gpio(struct gpio_desc *gpio, bool is_active)
+{
+	int ret, val;
+
+	ret = read_poll_timeout(gpiod_get_value, val,
+				val < 0 || !!val == is_active,
+				SYSCONFIG_POLL_INTERVAL_US,
+				SYSCONFIG_POLL_GPIO_TIMEOUT_US, false, gpio);
+
+	if (val < 0)
+		return val;
+
+	return ret;
+}
+
+static int sysconfig_gpio_refresh(struct sysconfig_priv *priv)
+{
+	struct gpio_desc *program = priv->program;
+	struct gpio_desc *init = priv->init;
+	struct gpio_desc *done = priv->done;
+	int ret;
+
+	/* Enter init mode */
+	gpiod_set_value(program, 1);
+
+	ret = sysconfig_poll_gpio(init, true);
+	if (!ret)
+		ret = sysconfig_poll_gpio(done, false);
+
+	if (ret)
+		return ret;
+
+	/* Enter program mode */
+	gpiod_set_value(program, 0);
+
+	return sysconfig_poll_gpio(init, false);
+}
+
+static int sysconfig_lsc_refresh(struct sysconfig_priv *priv)
+{
+	static const u8 lsc_refresh[] = SYSCONFIG_LSC_REFRESH;
+	int ret;
+
+	ret = sysconfig_cmd_write(priv, lsc_refresh, sizeof(lsc_refresh));
+	if (ret)
+		return ret;
+
+	usleep_range(4000, 8000);
+
+	return 0;
+}
+
+static int sysconfig_refresh(struct sysconfig_priv *priv)
+{
+	struct gpio_desc *program = priv->program;
+	struct gpio_desc *init = priv->init;
+	struct gpio_desc *done = priv->done;
+
+	if (program && init && done)
+		return sysconfig_gpio_refresh(priv);
+
+	return sysconfig_lsc_refresh(priv);
+}
+
+static int sysconfig_isc_enable(struct sysconfig_priv *priv)
+{
+	u8 isc_enable[] = SYSCONFIG_ISC_ENABLE;
+	u32 status;
+	int ret;
+
+	ret = sysconfig_cmd_write(priv, isc_enable, sizeof(isc_enable));
+	if (ret)
+		return ret;
+
+	ret = sysconfig_poll_status(priv, &status);
+	if (ret)
+		return ret;
+
+	if (status & SYSCONFIG_STATUS_FAIL)
+		return -EFAULT;
+
+	return 0;
+}
+
+static int sysconfig_isc_erase(struct sysconfig_priv *priv)
+{
+	u8 isc_erase[] = SYSCONFIG_ISC_ERASE;
+	u32 status;
+	int ret;
+
+	ret = sysconfig_cmd_write(priv, isc_erase, sizeof(isc_erase));
+	if (ret)
+		return ret;
+
+	ret = sysconfig_poll_status(priv, &status);
+	if (ret)
+		return ret;
+
+	if (status & SYSCONFIG_STATUS_FAIL)
+		return -EFAULT;
+
+	return 0;
+}
+
+static int sysconfig_isc_init(struct sysconfig_priv *priv)
+{
+	int ret = sysconfig_isc_enable(priv);
+
+	if (ret)
+		return ret;
+
+	return sysconfig_isc_erase(priv);
+}
+
+static int sysconfig_lsc_init_addr(struct sysconfig_priv *priv)
+{
+	const u8 lsc_init_addr[] = SYSCONFIG_LSC_INIT_ADDR;
+
+	return sysconfig_cmd_write(priv, lsc_init_addr, sizeof(lsc_init_addr));
+}
+
+static int sysconfig_burst_write_init(struct sysconfig_priv *priv)
+{
+	return priv->bitstream_burst_write_init(priv);
+}
+
+static int sysconfig_burst_write_complete(struct sysconfig_priv *priv)
+{
+	return priv->bitstream_burst_write_complete(priv);
+}
+
+static int sysconfig_bitstream_burst_write(struct sysconfig_priv *priv,
+					   const char *buf, size_t count)
+{
+	int ret = priv->bitstream_burst_write(priv, buf, count);
+
+	if (ret)
+		sysconfig_burst_write_complete(priv);
+
+	return ret;
+}
+
+static int sysconfig_isc_disable(struct sysconfig_priv *priv)
+{
+	const u8 isc_disable[] = SYSCONFIG_ISC_DISABLE;
+
+	return sysconfig_cmd_write(priv, isc_disable, sizeof(isc_disable));
+}
+
+static void sysconfig_cleanup(struct sysconfig_priv *priv)
+{
+	sysconfig_isc_erase(priv);
+	sysconfig_refresh(priv);
+}
+
+static int sysconfig_isc_finish(struct sysconfig_priv *priv)
+{
+	struct gpio_desc *done_gpio = priv->done;
+	u32 status;
+	int ret;
+
+	if (done_gpio) {
+		ret = sysconfig_isc_disable(priv);
+		if (ret)
+			return ret;
+
+		return sysconfig_poll_gpio(done_gpio, true);
+	}
+
+	ret = sysconfig_poll_status(priv, &status);
+	if (ret)
+		return ret;
+
+	if ((status & SYSCONFIG_STATUS_DONE) &&
+	    !(status & SYSCONFIG_STATUS_BUSY) &&
+	    !(status & SYSCONFIG_STATUS_ERR))
+		return sysconfig_isc_disable(priv);
+
+	return -EFAULT;
+}
+
+static enum fpga_mgr_states sysconfig_ops_state(struct fpga_manager *mgr)
+{
+	struct sysconfig_priv *priv = mgr->priv;
+	struct gpio_desc *done = priv->done;
+	u32 status;
+	int ret;
+
+	if (done && (gpiod_get_value(done) > 0))
+		return FPGA_MGR_STATE_OPERATING;
+
+	ret = sysconfig_read_status(priv, &status);
+	if (!ret && (status & SYSCONFIG_STATUS_DONE))
+		return FPGA_MGR_STATE_OPERATING;
+
+	return FPGA_MGR_STATE_UNKNOWN;
+}
+
+static int sysconfig_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 program mode */
+	ret = sysconfig_refresh(priv);
+	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;
+	}
+
+	/* Prepare for bitstream burst write */
+	ret = sysconfig_burst_write_init(priv);
+	if (ret)
+		dev_err(dev, "Failed to prepare for bitstream burst write\n");
+
+	return ret;
+}
+
+static int sysconfig_ops_write(struct fpga_manager *mgr, const char *buf,
+			       size_t count)
+{
+	return sysconfig_bitstream_burst_write(mgr->priv, buf, count);
+}
+
+static int sysconfig_ops_write_complete(struct fpga_manager *mgr,
+					struct fpga_image_info *info)
+{
+	struct sysconfig_priv *priv = mgr->priv;
+	struct device *dev = &mgr->dev;
+	int ret;
+
+	ret = sysconfig_burst_write_complete(priv);
+	if (!ret)
+		ret = sysconfig_poll_busy(priv);
+
+	if (ret) {
+		dev_err(dev, "Error while waiting bitstream write to finish\n");
+		goto fail;
+	}
+
+	ret = sysconfig_isc_finish(priv);
+
+fail:
+	if (ret)
+		sysconfig_cleanup(priv);
+
+	return ret;
+}
+
+static const struct fpga_manager_ops sysconfig_fpga_mgr_ops = {
+	.state = sysconfig_ops_state,
+	.write_init = sysconfig_ops_write_init,
+	.write = sysconfig_ops_write,
+	.write_complete = sysconfig_ops_write_complete,
+};
+
+int sysconfig_probe(struct sysconfig_priv *priv)
+{
+	struct gpio_desc *program, *init, *done;
+	struct device *dev = priv->dev;
+	struct fpga_manager *mgr;
+
+	if (!dev)
+		return -ENODEV;
+
+	if (!priv->command_transfer ||
+	    !priv->bitstream_burst_write_init ||
+	    !priv->bitstream_burst_write ||
+	    !priv->bitstream_burst_write_complete) {
+		dev_err(dev, "Essential callback is missing\n");
+		return -EINVAL;
+	}
+
+	program = devm_gpiod_get_optional(dev, "program", GPIOD_OUT_LOW);
+	if (IS_ERR(program))
+		return dev_err_probe(dev, PTR_ERR(program),
+				     "Failed to get PROGRAM GPIO\n");
+
+	init = devm_gpiod_get_optional(dev, "init", GPIOD_IN);
+	if (IS_ERR(init))
+		return dev_err_probe(dev, PTR_ERR(init),
+				     "Failed to get INIT GPIO\n");
+
+	done = devm_gpiod_get_optional(dev, "done", GPIOD_IN);
+	if (IS_ERR(done))
+		return dev_err_probe(dev, PTR_ERR(done),
+				     "Failed to get DONE GPIO\n");
+
+	priv->program = program;
+	priv->init = init;
+	priv->done = done;
+
+	mgr = devm_fpga_mgr_register(dev, "Lattice sysCONFIG FPGA Manager",
+				     &sysconfig_fpga_mgr_ops, priv);
+
+	return PTR_ERR_OR_ZERO(mgr);
+}
+EXPORT_SYMBOL(sysconfig_probe);
+
+MODULE_DESCRIPTION("Lattice sysCONFIG FPGA Manager Core");
+MODULE_LICENSE("GPL");
diff --git a/drivers/fpga/lattice-sysconfig.h b/drivers/fpga/lattice-sysconfig.h
new file mode 100644
index 000000000000..df47d9a524f6
--- /dev/null
+++ b/drivers/fpga/lattice-sysconfig.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef	__LATTICE_SYSCONFIG_H
+#define	__LATTICE_SYSCONFIG_H
+
+#define	SYSCONFIG_ISC_ENABLE		{0xC6, 0x00, 0x00, 0x00}
+#define	SYSCONFIG_ISC_DISABLE		{0x26, 0x00, 0x00, 0x00}
+#define	SYSCONFIG_ISC_ERASE		{0x0E, 0x01, 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_STATUS_DONE		BIT(8)
+#define	SYSCONFIG_STATUS_BUSY		BIT(12)
+#define	SYSCONFIG_STATUS_FAIL		BIT(13)
+#define	SYSCONFIG_STATUS_ERR		GENMASK(25, 23)
+
+#define	SYSCONFIG_POLL_INTERVAL_US	30
+#define	SYSCONFIG_POLL_BUSY_TIMEOUT_US	1000000
+#define	SYSCONFIG_POLL_GPIO_TIMEOUT_US	100000
+
+struct sysconfig_priv {
+	struct gpio_desc *program;
+	struct gpio_desc *init;
+	struct gpio_desc *done;
+	struct device *dev;
+	int (*command_transfer)(struct sysconfig_priv *priv, const void *tx_buf,
+				size_t tx_len, void *rx_buf, size_t rx_len);
+	int (*bitstream_burst_write_init)(struct sysconfig_priv *priv);
+	int (*bitstream_burst_write)(struct sysconfig_priv *priv,
+				     const char *tx_buf, size_t tx_len);
+	int (*bitstream_burst_write_complete)(struct sysconfig_priv *priv);
+};
+
+int sysconfig_probe(struct sysconfig_priv *priv);
+
+#endif /* __LATTICE_SYSCONFIG_H */
-- 
2.37.3