fpga manager: Add Altera CvP driver

Add FPGA manager driver for loading Arria-V/Cyclone-V/Stratix-V
and Arria-10 FPGAs via CvP.

Signed-off-by: Anatolij Gustschin <[e-mail]>
Reviewed-by: Andy Shevchenko <[e-mail]>
Signed-off-by: Alan Tull <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

Documentation/ABI/testing/sysfs-driver-altera-cvp

···
+What:		/sys/bus/pci/drivers/altera-cvp/chkcfg
+Date:		May 2017
+Kernel Version:	4.13
+Contact:	Anatolij Gustschin <[e-mail]>
+Description:
+		Contains either 1 or 0 and controls if configuration
+		error checking in altera-cvp driver is turned on or
+		off.

drivers/fpga/Kconfig

···
 	help
 	  FPGA manager driver support for Lattice iCE40 FPGAs over SPI.
 
+config FPGA_MGR_ALTERA_CVP
+	tristate "Altera Arria-V/Cyclone-V/Stratix-V CvP FPGA Manager"
+	depends on PCI
+	help
+	  FPGA manager driver support for Arria-V, Cyclone-V, Stratix-V
+	  and Arria 10 Altera FPGAs using the CvP interface over PCIe.
+
 config FPGA_MGR_ALTERA_PS_SPI
 	tristate "Altera FPGA Passive Serial over SPI"
 	depends on SPI

drivers/fpga/Makefile

···
 obj-$(CONFIG_FPGA)			+= fpga-mgr.o
 
 # FPGA Manager Drivers
+obj-$(CONFIG_FPGA_MGR_ALTERA_CVP)	+= altera-cvp.o
 obj-$(CONFIG_FPGA_MGR_ALTERA_PS_SPI)	+= altera-ps-spi.o
 obj-$(CONFIG_FPGA_MGR_ICE40_SPI)	+= ice40-spi.o
 obj-$(CONFIG_FPGA_MGR_SOCFPGA)		+= socfpga.o

drivers/fpga/altera-cvp.c

···
+/*
+ * FPGA Manager Driver for Altera Arria/Cyclone/Stratix CvP
+ *
+ * Copyright (C) 2017 DENX Software Engineering
+ *
+ * Anatolij Gustschin <[e-mail]>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * Manage Altera FPGA firmware using PCIe CvP.
+ * Firmware must be in binary "rbf" format.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/fpga/fpga-mgr.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <linux/sizes.h>
+
+#define CVP_BAR		0	/* BAR used for data transfer in memory mode */
+#define CVP_DUMMY_WR	244	/* dummy writes to clear CvP state machine */
+#define TIMEOUT_US	2000	/* CVP STATUS timeout for USERMODE polling */
+
+/* Vendor Specific Extended Capability Registers */
+#define VSE_PCIE_EXT_CAP_ID		0x200
+#define VSE_PCIE_EXT_CAP_ID_VAL		0x000b	/* 16bit */
+
+#define VSE_CVP_STATUS			0x21c	/* 32bit */
+#define VSE_CVP_STATUS_CFG_RDY		BIT(18)	/* CVP_CONFIG_READY */
+#define VSE_CVP_STATUS_CFG_ERR		BIT(19)	/* CVP_CONFIG_ERROR */
+#define VSE_CVP_STATUS_CVP_EN		BIT(20)	/* ctrl block is enabling CVP */
+#define VSE_CVP_STATUS_USERMODE		BIT(21)	/* USERMODE */
+#define VSE_CVP_STATUS_CFG_DONE		BIT(23)	/* CVP_CONFIG_DONE */
+#define VSE_CVP_STATUS_PLD_CLK_IN_USE	BIT(24)	/* PLD_CLK_IN_USE */
+
+#define VSE_CVP_MODE_CTRL		0x220	/* 32bit */
+#define VSE_CVP_MODE_CTRL_CVP_MODE	BIT(0)	/* CVP (1) or normal mode (0) */
+#define VSE_CVP_MODE_CTRL_HIP_CLK_SEL	BIT(1) /* PMA (1) or fabric clock (0) */
+#define VSE_CVP_MODE_CTRL_NUMCLKS_OFF	8	/* NUMCLKS bits offset */
+#define VSE_CVP_MODE_CTRL_NUMCLKS_MASK	GENMASK(15, 8)
+
+#define VSE_CVP_DATA			0x228	/* 32bit */
+#define VSE_CVP_PROG_CTRL		0x22c	/* 32bit */
+#define VSE_CVP_PROG_CTRL_CONFIG	BIT(0)
+#define VSE_CVP_PROG_CTRL_START_XFER	BIT(1)
+
+#define VSE_UNCOR_ERR_STATUS		0x234	/* 32bit */
+#define VSE_UNCOR_ERR_CVP_CFG_ERR	BIT(5)	/* CVP_CONFIG_ERROR_LATCHED */
+
+#define DRV_NAME		"altera-cvp"
+#define ALTERA_CVP_MGR_NAME	"Altera CvP FPGA Manager"
+
+/* Optional CvP config error status check for debugging */
+static bool altera_cvp_chkcfg;
+
+struct altera_cvp_conf {
+	struct fpga_manager	*mgr;
+	struct pci_dev		*pci_dev;
+	void __iomem		*map;
+	void			(*write_data)(struct altera_cvp_conf *, u32);
+	char			mgr_name[64];
+	u8			numclks;
+};
+
+static enum fpga_mgr_states altera_cvp_state(struct fpga_manager *mgr)
+{
+	struct altera_cvp_conf *conf = mgr->priv;
+	u32 status;
+
+	pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &status);
+
+	if (status & VSE_CVP_STATUS_CFG_DONE)
+		return FPGA_MGR_STATE_OPERATING;
+
+	if (status & VSE_CVP_STATUS_CVP_EN)
+		return FPGA_MGR_STATE_POWER_UP;
+
+	return FPGA_MGR_STATE_UNKNOWN;
+}
+
+static void altera_cvp_write_data_iomem(struct altera_cvp_conf *conf, u32 val)
+{
+	writel(val, conf->map);
+}
+
+static void altera_cvp_write_data_config(struct altera_cvp_conf *conf, u32 val)
+{
+	pci_write_config_dword(conf->pci_dev, VSE_CVP_DATA, val);
+}
+
+/* switches between CvP clock and internal clock */
+static void altera_cvp_dummy_write(struct altera_cvp_conf *conf)
+{
+	unsigned int i;
+	u32 val;
+
+	/* set 1 CVP clock cycle for every CVP Data Register Write */
+	pci_read_config_dword(conf->pci_dev, VSE_CVP_MODE_CTRL, &val);
+	val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
+	val |= 1 << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
+	pci_write_config_dword(conf->pci_dev, VSE_CVP_MODE_CTRL, val);
+
+	for (i = 0; i < CVP_DUMMY_WR; i++)
+		conf->write_data(conf, 0); /* dummy data, could be any value */
+}
+
+static int altera_cvp_wait_status(struct altera_cvp_conf *conf, u32 status_mask,
+				  u32 status_val, int timeout_us)
+{
+	unsigned int retries;
+	u32 val;
+
+	retries = timeout_us / 10;
+	if (timeout_us % 10)
+		retries++;
+
+	do {
+		pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &val);
+		if ((val & status_mask) == status_val)
+			return 0;
+
+		/* use small usleep value to re-check and break early */
+		usleep_range(10, 11);
+	} while (--retries);
+
+	return -ETIMEDOUT;
+}
+
+static int altera_cvp_teardown(struct fpga_manager *mgr,
+			       struct fpga_image_info *info)
+{
+	struct altera_cvp_conf *conf = mgr->priv;
+	struct pci_dev *pdev = conf->pci_dev;
+	int ret;
+	u32 val;
+
+	/* STEP 12 - reset START_XFER bit */
+	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
+	val &= ~VSE_CVP_PROG_CTRL_START_XFER;
+	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
+
+	/* STEP 13 - reset CVP_CONFIG bit */
+	val &= ~VSE_CVP_PROG_CTRL_CONFIG;
+	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
+
+	/*
+	 * STEP 14
+	 * - set CVP_NUMCLKS to 1 and then issue CVP_DUMMY_WR dummy
+	 *   writes to the HIP
+	 */
+	altera_cvp_dummy_write(conf); /* from CVP clock to internal clock */
+
+	/* STEP 15 - poll CVP_CONFIG_READY bit for 0 with 10us timeout */
+	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY, 0, 10);
+	if (ret)
+		dev_err(&mgr->dev, "CFG_RDY == 0 timeout\n");
+
+	return ret;
+}
+
+static int altera_cvp_write_init(struct fpga_manager *mgr,
+				 struct fpga_image_info *info,
+				 const char *buf, size_t count)
+{
+	struct altera_cvp_conf *conf = mgr->priv;
+	struct pci_dev *pdev = conf->pci_dev;
+	u32 iflags, val;
+	int ret;
+
+	iflags = info ? info->flags : 0;
+
+	if (iflags & FPGA_MGR_PARTIAL_RECONFIG) {
+		dev_err(&mgr->dev, "Partial reconfiguration not supported.\n");
+		return -EINVAL;
+	}
+
+	/* Determine allowed clock to data ratio */
+	if (iflags & FPGA_MGR_COMPRESSED_BITSTREAM)
+		conf->numclks = 8; /* ratio for all compressed images */
+	else if (iflags & FPGA_MGR_ENCRYPTED_BITSTREAM)
+		conf->numclks = 4; /* for uncompressed and encrypted images */
+	else
+		conf->numclks = 1; /* for uncompressed and unencrypted images */
+
+	/* STEP 1 - read CVP status and check CVP_EN flag */
+	pci_read_config_dword(pdev, VSE_CVP_STATUS, &val);
+	if (!(val & VSE_CVP_STATUS_CVP_EN)) {
+		dev_err(&mgr->dev, "CVP mode off: 0x%04x\n", val);
+		return -ENODEV;
+	}
+
+	if (val & VSE_CVP_STATUS_CFG_RDY) {
+		dev_warn(&mgr->dev, "CvP already started, teardown first\n");
+		ret = altera_cvp_teardown(mgr, info);
+		if (ret)
+			return ret;
+	}
+
+	/*
+	 * STEP 2
+	 * - set HIP_CLK_SEL and CVP_MODE (must be set in the order mentioned)
+	 */
+	/* switch from fabric to PMA clock */
+	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
+	val |= VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
+	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
+
+	/* set CVP mode */
+	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
+	val |= VSE_CVP_MODE_CTRL_CVP_MODE;
+	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
+
+	/*
+	 * STEP 3
+	 * - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
+	 */
+	altera_cvp_dummy_write(conf);
+
+	/* STEP 4 - set CVP_CONFIG bit */
+	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
+	/* request control block to begin transfer using CVP */
+	val |= VSE_CVP_PROG_CTRL_CONFIG;
+	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
+
+	/* STEP 5 - poll CVP_CONFIG READY for 1 with 10us timeout */
+	ret = altera_cvp_wait_status(conf, VSE_CVP_STATUS_CFG_RDY,
+				     VSE_CVP_STATUS_CFG_RDY, 10);
+	if (ret) {
+		dev_warn(&mgr->dev, "CFG_RDY == 1 timeout\n");
+		return ret;
+	}
+
+	/*
+	 * STEP 6
+	 * - set CVP_NUMCLKS to 1 and issue CVP_DUMMY_WR dummy writes to the HIP
+	 */
+	altera_cvp_dummy_write(conf);
+
+	/* STEP 7 - set START_XFER */
+	pci_read_config_dword(pdev, VSE_CVP_PROG_CTRL, &val);
+	val |= VSE_CVP_PROG_CTRL_START_XFER;
+	pci_write_config_dword(pdev, VSE_CVP_PROG_CTRL, val);
+
+	/* STEP 8 - start transfer (set CVP_NUMCLKS for bitstream) */
+	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
+	val &= ~VSE_CVP_MODE_CTRL_NUMCLKS_MASK;
+	val |= conf->numclks << VSE_CVP_MODE_CTRL_NUMCLKS_OFF;
+	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
+
+	return 0;
+}
+
+static inline int altera_cvp_chk_error(struct fpga_manager *mgr, size_t bytes)
+{
+	struct altera_cvp_conf *conf = mgr->priv;
+	u32 val;
+
+	/* STEP 10 (optional) - check CVP_CONFIG_ERROR flag */
+	pci_read_config_dword(conf->pci_dev, VSE_CVP_STATUS, &val);
+	if (val & VSE_CVP_STATUS_CFG_ERR) {
+		dev_err(&mgr->dev, "CVP_CONFIG_ERROR after %zu bytes!\n",
+			bytes);
+		return -EPROTO;
+	}
+	return 0;
+}
+
+static int altera_cvp_write(struct fpga_manager *mgr, const char *buf,
+			    size_t count)
+{
+	struct altera_cvp_conf *conf = mgr->priv;
+	const u32 *data;
+	size_t done, remaining;
+	int status = 0;
+	u32 mask;
+
+	/* STEP 9 - write 32-bit data from RBF file to CVP data register */
+	data = (u32 *)buf;
+	remaining = count;
+	done = 0;
+
+	while (remaining >= 4) {
+		conf->write_data(conf, *data++);
+		done += 4;
+		remaining -= 4;
+
+		/*
+		 * STEP 10 (optional) and STEP 11
+		 * - check error flag
+		 * - loop until data transfer completed
+		 * Config images can be huge (more than 40 MiB), so
+		 * only check after a new 4k data block has been written.
+		 * This reduces the number of checks and speeds up the
+		 * configuration process.
+		 */
+		if (altera_cvp_chkcfg && !(done % SZ_4K)) {
+			status = altera_cvp_chk_error(mgr, done);
+			if (status < 0)
+				return status;
+		}
+	}
+
+	/* write up to 3 trailing bytes, if any */
+	mask = BIT(remaining * 8) - 1;
+	if (mask)
+		conf->write_data(conf, *data & mask);
+
+	if (altera_cvp_chkcfg)
+		status = altera_cvp_chk_error(mgr, count);
+
+	return status;
+}
+
+static int altera_cvp_write_complete(struct fpga_manager *mgr,
+				     struct fpga_image_info *info)
+{
+	struct altera_cvp_conf *conf = mgr->priv;
+	struct pci_dev *pdev = conf->pci_dev;
+	int ret;
+	u32 mask;
+	u32 val;
+
+	ret = altera_cvp_teardown(mgr, info);
+	if (ret)
+		return ret;
+
+	/* STEP 16 - check CVP_CONFIG_ERROR_LATCHED bit */
+	pci_read_config_dword(pdev, VSE_UNCOR_ERR_STATUS, &val);
+	if (val & VSE_UNCOR_ERR_CVP_CFG_ERR) {
+		dev_err(&mgr->dev, "detected CVP_CONFIG_ERROR_LATCHED!\n");
+		return -EPROTO;
+	}
+
+	/* STEP 17 - reset CVP_MODE and HIP_CLK_SEL bit */
+	pci_read_config_dword(pdev, VSE_CVP_MODE_CTRL, &val);
+	val &= ~VSE_CVP_MODE_CTRL_HIP_CLK_SEL;
+	val &= ~VSE_CVP_MODE_CTRL_CVP_MODE;
+	pci_write_config_dword(pdev, VSE_CVP_MODE_CTRL, val);
+
+	/* STEP 18 - poll PLD_CLK_IN_USE and USER_MODE bits */
+	mask = VSE_CVP_STATUS_PLD_CLK_IN_USE | VSE_CVP_STATUS_USERMODE;
+	ret = altera_cvp_wait_status(conf, mask, mask, TIMEOUT_US);
+	if (ret)
+		dev_err(&mgr->dev, "PLD_CLK_IN_USE|USERMODE timeout\n");
+
+	return ret;
+}
+
+static const struct fpga_manager_ops altera_cvp_ops = {
+	.state		= altera_cvp_state,
+	.write_init	= altera_cvp_write_init,
+	.write		= altera_cvp_write,
+	.write_complete	= altera_cvp_write_complete,
+};
+
+static ssize_t show_chkcfg(struct device_driver *dev, char *buf)
+{
+	return snprintf(buf, 3, "%d\n", altera_cvp_chkcfg);
+}
+
+static ssize_t store_chkcfg(struct device_driver *drv, const char *buf,
+			    size_t count)
+{
+	int ret;
+
+	ret = kstrtobool(buf, &altera_cvp_chkcfg);
+	if (ret)
+		return ret;
+
+	return count;
+}
+
+static DRIVER_ATTR(chkcfg, 0600, show_chkcfg, store_chkcfg);
+
+static int altera_cvp_probe(struct pci_dev *pdev,
+			    const struct pci_device_id *dev_id);
+static void altera_cvp_remove(struct pci_dev *pdev);
+
+#define PCI_VENDOR_ID_ALTERA	0x1172
+
+static struct pci_device_id altera_cvp_id_tbl[] = {
+	{ PCI_VDEVICE(ALTERA, PCI_ANY_ID) },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, altera_cvp_id_tbl);
+
+static struct pci_driver altera_cvp_driver = {
+	.name   = DRV_NAME,
+	.id_table = altera_cvp_id_tbl,
+	.probe  = altera_cvp_probe,
+	.remove = altera_cvp_remove,
+};
+
+static int altera_cvp_probe(struct pci_dev *pdev,
+			    const struct pci_device_id *dev_id)
+{
+	struct altera_cvp_conf *conf;
+	u16 cmd, val;
+	int ret;
+
+	/*
+	 * First check if this is the expected FPGA device. PCI config
+	 * space access works without enabling the PCI device, memory
+	 * space access is enabled further down.
+	 */
+	pci_read_config_word(pdev, VSE_PCIE_EXT_CAP_ID, &val);
+	if (val != VSE_PCIE_EXT_CAP_ID_VAL) {
+		dev_err(&pdev->dev, "Wrong EXT_CAP_ID value 0x%x\n", val);
+		return -ENODEV;
+	}
+
+	conf = devm_kzalloc(&pdev->dev, sizeof(*conf), GFP_KERNEL);
+	if (!conf)
+		return -ENOMEM;
+
+	/*
+	 * Enable memory BAR access. We cannot use pci_enable_device() here
+	 * because it will make the driver unusable with FPGA devices that
+	 * have additional big IOMEM resources (e.g. 4GiB BARs) on 32-bit
+	 * platform. Such BARs will not have an assigned address range and
+	 * pci_enable_device() will fail, complaining about not claimed BAR,
+	 * even if the concerned BAR is not needed for FPGA configuration
+	 * at all. Thus, enable the device via PCI config space command.
+	 */
+	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
+	if (!(cmd & PCI_COMMAND_MEMORY)) {
+		cmd |= PCI_COMMAND_MEMORY;
+		pci_write_config_word(pdev, PCI_COMMAND, cmd);
+	}
+
+	ret = pci_request_region(pdev, CVP_BAR, "CVP");
+	if (ret) {
+		dev_err(&pdev->dev, "Requesting CVP BAR region failed\n");
+		goto err_disable;
+	}
+
+	conf->pci_dev = pdev;
+	conf->write_data = altera_cvp_write_data_iomem;
+
+	conf->map = pci_iomap(pdev, CVP_BAR, 0);
+	if (!conf->map) {
+		dev_warn(&pdev->dev, "Mapping CVP BAR failed\n");
+		conf->write_data = altera_cvp_write_data_config;
+	}
+
+	snprintf(conf->mgr_name, sizeof(conf->mgr_name), "%s @%s",
+		 ALTERA_CVP_MGR_NAME, pci_name(pdev));
+
+	ret = fpga_mgr_register(&pdev->dev, conf->mgr_name,
+				&altera_cvp_ops, conf);
+	if (ret)
+		goto err_unmap;
+
+	ret = driver_create_file(&altera_cvp_driver.driver,
+				 &driver_attr_chkcfg);
+	if (ret) {
+		dev_err(&pdev->dev, "Can't create sysfs chkcfg file\n");
+		fpga_mgr_unregister(&pdev->dev);
+		goto err_unmap;
+	}
+
+	return 0;
+
+err_unmap:
+	pci_iounmap(pdev, conf->map);
+	pci_release_region(pdev, CVP_BAR);
+err_disable:
+	cmd &= ~PCI_COMMAND_MEMORY;
+	pci_write_config_word(pdev, PCI_COMMAND, cmd);
+	return ret;
+}
+
+static void altera_cvp_remove(struct pci_dev *pdev)
+{
+	struct fpga_manager *mgr = pci_get_drvdata(pdev);
+	struct altera_cvp_conf *conf = mgr->priv;
+	u16 cmd;
+
+	driver_remove_file(&altera_cvp_driver.driver, &driver_attr_chkcfg);
+	fpga_mgr_unregister(&pdev->dev);
+	pci_iounmap(pdev, conf->map);
+	pci_release_region(pdev, CVP_BAR);
+	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
+	cmd &= ~PCI_COMMAND_MEMORY;
+	pci_write_config_word(pdev, PCI_COMMAND, cmd);
+}
+
+module_pci_driver(altera_cvp_driver);
+
+MODULE_LICENSE("GPL v2");
+MODULE_AUTHOR("Anatolij Gustschin <[e-mail]>");
+MODULE_DESCRIPTION("Module to load Altera FPGA over CvP");