net: marvell: prestera: Add PCI interface support

Add PCI interface driver for Prestera Switch ASICs family devices, which
provides:

    - Firmware loading mechanism
    - Requests & events handling to/from the firmware
    - Access to the firmware on the bus level

The firmware has to be loaded each time the device is reset. The driver
is loading it from:

    /lib/firmware/mrvl/prestera/mvsw_prestera_fw-v{MAJOR}.{MINOR}.img

The full firmware image version is located within the internal header
and consists of 3 numbers - MAJOR.MINOR.PATCH. Additionally, driver has
hard-coded minimum supported firmware version which it can work with:

    MAJOR - reflects the support on ABI level between driver and loaded
            firmware, this number should be the same for driver and loaded
            firmware.

    MINOR - this is the minimum supported version between driver and the
            firmware.

    PATCH - indicates only fixes, firmware ABI is not changed.

Firmware image file name contains only MAJOR and MINOR numbers to make
driver be compatible with any PATCH version.
Co-developed-by: Oleksandr Mazur <oleksandr.mazur@plvision.eu>
Signed-off-by: Oleksandr Mazur <oleksandr.mazur@plvision.eu>
Signed-off-by: Vadym Kochan <vadym.kochan@plvision.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/prestera/Kconfig

@@ -11,3 +11,14 @@ config PRESTERA
 
 	  To compile this driver as a module, choose M here: the
 	  module will be called prestera.
+
+config PRESTERA_PCI
+	tristate "PCI interface driver for Marvell Prestera Switch ASICs family"
+	depends on PCI && HAS_IOMEM && PRESTERA
+	default PRESTERA
+	help
+	  This is implementation of PCI interface support for Marvell Prestera
+	  Switch ASICs family.
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called prestera_pci.

drivers/net/ethernet/marvell/prestera/Makefile

@@ -2,3 +2,5 @@
 obj-$(CONFIG_PRESTERA)	+= prestera.o
 prestera-objs		:= prestera_main.o prestera_hw.o prestera_dsa.o \
 			   prestera_rxtx.o
+
+obj-$(CONFIG_PRESTERA_PCI)	+= prestera_pci.o

drivers/net/ethernet/marvell/prestera/prestera_pci.c

+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/* Copyright (c) 2019-2020 Marvell International Ltd. All rights reserved */
+
+#include <linux/circ_buf.h>
+#include <linux/device.h>
+#include <linux/firmware.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+
+#include "prestera.h"
+
+#define PRESTERA_MSG_MAX_SIZE 1500
+
+#define PRESTERA_SUPP_FW_MAJ_VER	2
+#define PRESTERA_SUPP_FW_MIN_VER	0
+
+#define PRESTERA_FW_PATH_FMT	"mrvl/prestera/mvsw_prestera_fw-v%u.%u.img"
+
+#define PRESTERA_FW_HDR_MAGIC		0x351D9D06
+#define PRESTERA_FW_DL_TIMEOUT_MS	50000
+#define PRESTERA_FW_BLK_SZ		1024
+
+#define PRESTERA_FW_VER_MAJ_MUL 1000000
+#define PRESTERA_FW_VER_MIN_MUL 1000
+
+#define PRESTERA_FW_VER_MAJ(v)	((v) / PRESTERA_FW_VER_MAJ_MUL)
+
+#define PRESTERA_FW_VER_MIN(v) \
+	(((v) - (PRESTERA_FW_VER_MAJ(v) * PRESTERA_FW_VER_MAJ_MUL)) / \
+			PRESTERA_FW_VER_MIN_MUL)
+
+#define PRESTERA_FW_VER_PATCH(v) \
+	((v) - (PRESTERA_FW_VER_MAJ(v) * PRESTERA_FW_VER_MAJ_MUL) - \
+			(PRESTERA_FW_VER_MIN(v) * PRESTERA_FW_VER_MIN_MUL))
+
+enum prestera_pci_bar_t {
+	PRESTERA_PCI_BAR_FW = 2,
+	PRESTERA_PCI_BAR_PP = 4,
+};
+
+struct prestera_fw_header {
+	__be32 magic_number;
+	__be32 version_value;
+	u8 reserved[8];
+};
+
+struct prestera_ldr_regs {
+	u32 ldr_ready;
+	u32 pad1;
+
+	u32 ldr_img_size;
+	u32 ldr_ctl_flags;
+
+	u32 ldr_buf_offs;
+	u32 ldr_buf_size;
+
+	u32 ldr_buf_rd;
+	u32 pad2;
+	u32 ldr_buf_wr;
+
+	u32 ldr_status;
+};
+
+#define PRESTERA_LDR_REG_OFFSET(f)	offsetof(struct prestera_ldr_regs, f)
+
+#define PRESTERA_LDR_READY_MAGIC	0xf00dfeed
+
+#define PRESTERA_LDR_STATUS_IMG_DL	BIT(0)
+#define PRESTERA_LDR_STATUS_START_FW	BIT(1)
+#define PRESTERA_LDR_STATUS_INVALID_IMG	BIT(2)
+#define PRESTERA_LDR_STATUS_NOMEM	BIT(3)
+
+#define PRESTERA_LDR_REG_BASE(fw)	((fw)->ldr_regs)
+#define PRESTERA_LDR_REG_ADDR(fw, reg)	(PRESTERA_LDR_REG_BASE(fw) + (reg))
+
+/* fw loader registers */
+#define PRESTERA_LDR_READY_REG		PRESTERA_LDR_REG_OFFSET(ldr_ready)
+#define PRESTERA_LDR_IMG_SIZE_REG	PRESTERA_LDR_REG_OFFSET(ldr_img_size)
+#define PRESTERA_LDR_CTL_REG		PRESTERA_LDR_REG_OFFSET(ldr_ctl_flags)
+#define PRESTERA_LDR_BUF_SIZE_REG	PRESTERA_LDR_REG_OFFSET(ldr_buf_size)
+#define PRESTERA_LDR_BUF_OFFS_REG	PRESTERA_LDR_REG_OFFSET(ldr_buf_offs)
+#define PRESTERA_LDR_BUF_RD_REG		PRESTERA_LDR_REG_OFFSET(ldr_buf_rd)
+#define PRESTERA_LDR_BUF_WR_REG		PRESTERA_LDR_REG_OFFSET(ldr_buf_wr)
+#define PRESTERA_LDR_STATUS_REG		PRESTERA_LDR_REG_OFFSET(ldr_status)
+
+#define PRESTERA_LDR_CTL_DL_START	BIT(0)
+
+#define PRESTERA_EVT_QNUM_MAX	4
+
+struct prestera_fw_evtq_regs {
+	u32 rd_idx;
+	u32 pad1;
+	u32 wr_idx;
+	u32 pad2;
+	u32 offs;
+	u32 len;
+};
+
+struct prestera_fw_regs {
+	u32 fw_ready;
+	u32 pad;
+	u32 cmd_offs;
+	u32 cmd_len;
+	u32 evt_offs;
+	u32 evt_qnum;
+
+	u32 cmd_req_ctl;
+	u32 cmd_req_len;
+	u32 cmd_rcv_ctl;
+	u32 cmd_rcv_len;
+
+	u32 fw_status;
+	u32 rx_status;
+
+	struct prestera_fw_evtq_regs evtq_list[PRESTERA_EVT_QNUM_MAX];
+};
+
+#define PRESTERA_FW_REG_OFFSET(f)	offsetof(struct prestera_fw_regs, f)
+
+#define PRESTERA_FW_READY_MAGIC		0xcafebabe
+
+/* fw registers */
+#define PRESTERA_FW_READY_REG		PRESTERA_FW_REG_OFFSET(fw_ready)
+
+#define PRESTERA_CMD_BUF_OFFS_REG	PRESTERA_FW_REG_OFFSET(cmd_offs)
+#define PRESTERA_CMD_BUF_LEN_REG	PRESTERA_FW_REG_OFFSET(cmd_len)
+#define PRESTERA_EVT_BUF_OFFS_REG	PRESTERA_FW_REG_OFFSET(evt_offs)
+#define PRESTERA_EVT_QNUM_REG		PRESTERA_FW_REG_OFFSET(evt_qnum)
+
+#define PRESTERA_CMD_REQ_CTL_REG	PRESTERA_FW_REG_OFFSET(cmd_req_ctl)
+#define PRESTERA_CMD_REQ_LEN_REG	PRESTERA_FW_REG_OFFSET(cmd_req_len)
+
+#define PRESTERA_CMD_RCV_CTL_REG	PRESTERA_FW_REG_OFFSET(cmd_rcv_ctl)
+#define PRESTERA_CMD_RCV_LEN_REG	PRESTERA_FW_REG_OFFSET(cmd_rcv_len)
+#define PRESTERA_FW_STATUS_REG		PRESTERA_FW_REG_OFFSET(fw_status)
+#define PRESTERA_RX_STATUS_REG		PRESTERA_FW_REG_OFFSET(rx_status)
+
+/* PRESTERA_CMD_REQ_CTL_REG flags */
+#define PRESTERA_CMD_F_REQ_SENT		BIT(0)
+#define PRESTERA_CMD_F_REPL_RCVD	BIT(1)
+
+/* PRESTERA_CMD_RCV_CTL_REG flags */
+#define PRESTERA_CMD_F_REPL_SENT	BIT(0)
+
+#define PRESTERA_EVTQ_REG_OFFSET(q, f)			\
+	(PRESTERA_FW_REG_OFFSET(evtq_list) +		\
+	 (q) * sizeof(struct prestera_fw_evtq_regs) +	\
+	 offsetof(struct prestera_fw_evtq_regs, f))
+
+#define PRESTERA_EVTQ_RD_IDX_REG(q)	PRESTERA_EVTQ_REG_OFFSET(q, rd_idx)
+#define PRESTERA_EVTQ_WR_IDX_REG(q)	PRESTERA_EVTQ_REG_OFFSET(q, wr_idx)
+#define PRESTERA_EVTQ_OFFS_REG(q)	PRESTERA_EVTQ_REG_OFFSET(q, offs)
+#define PRESTERA_EVTQ_LEN_REG(q)	PRESTERA_EVTQ_REG_OFFSET(q, len)
+
+#define PRESTERA_FW_REG_BASE(fw)	((fw)->dev.ctl_regs)
+#define PRESTERA_FW_REG_ADDR(fw, reg)	PRESTERA_FW_REG_BASE((fw)) + (reg)
+
+#define PRESTERA_FW_CMD_DEFAULT_WAIT_MS	30000
+#define PRESTERA_FW_READY_WAIT_MS	20000
+
+struct prestera_fw_evtq {
+	u8 __iomem *addr;
+	size_t len;
+};
+
+struct prestera_fw {
+	struct workqueue_struct *wq;
+	struct prestera_device dev;
+	u8 __iomem *ldr_regs;
+	u8 __iomem *ldr_ring_buf;
+	u32 ldr_buf_len;
+	u32 ldr_wr_idx;
+	struct mutex cmd_mtx; /* serialize access to dev->send_req */
+	size_t cmd_mbox_len;
+	u8 __iomem *cmd_mbox;
+	struct prestera_fw_evtq evt_queue[PRESTERA_EVT_QNUM_MAX];
+	u8 evt_qnum;
+	struct work_struct evt_work;
+	u8 __iomem *evt_buf;
+	u8 *evt_msg;
+};
+
+static int prestera_fw_load(struct prestera_fw *fw);
+
+static void prestera_fw_write(struct prestera_fw *fw, u32 reg, u32 val)
+{
+	writel(val, PRESTERA_FW_REG_ADDR(fw, reg));
+}
+
+static u32 prestera_fw_read(struct prestera_fw *fw, u32 reg)
+{
+	return readl(PRESTERA_FW_REG_ADDR(fw, reg));
+}
+
+static u32 prestera_fw_evtq_len(struct prestera_fw *fw, u8 qid)
+{
+	return fw->evt_queue[qid].len;
+}
+
+static u32 prestera_fw_evtq_avail(struct prestera_fw *fw, u8 qid)
+{
+	u32 wr_idx = prestera_fw_read(fw, PRESTERA_EVTQ_WR_IDX_REG(qid));
+	u32 rd_idx = prestera_fw_read(fw, PRESTERA_EVTQ_RD_IDX_REG(qid));
+
+	return CIRC_CNT(wr_idx, rd_idx, prestera_fw_evtq_len(fw, qid));
+}
+
+static void prestera_fw_evtq_rd_set(struct prestera_fw *fw,
+				    u8 qid, u32 idx)
+{
+	u32 rd_idx = idx & (prestera_fw_evtq_len(fw, qid) - 1);
+
+	prestera_fw_write(fw, PRESTERA_EVTQ_RD_IDX_REG(qid), rd_idx);
+}
+
+static u8 __iomem *prestera_fw_evtq_buf(struct prestera_fw *fw, u8 qid)
+{
+	return fw->evt_queue[qid].addr;
+}
+
+static u32 prestera_fw_evtq_read32(struct prestera_fw *fw, u8 qid)
+{
+	u32 rd_idx = prestera_fw_read(fw, PRESTERA_EVTQ_RD_IDX_REG(qid));
+	u32 val;
+
+	val = readl(prestera_fw_evtq_buf(fw, qid) + rd_idx);
+	prestera_fw_evtq_rd_set(fw, qid, rd_idx + 4);
+	return val;
+}
+
+static ssize_t prestera_fw_evtq_read_buf(struct prestera_fw *fw,
+					 u8 qid, void *buf, size_t len)
+{
+	u32 idx = prestera_fw_read(fw, PRESTERA_EVTQ_RD_IDX_REG(qid));
+	u8 __iomem *evtq_addr = prestera_fw_evtq_buf(fw, qid);
+	u32 *buf32 = buf;
+	int i;
+
+	for (i = 0; i < len / 4; buf32++, i++) {
+		*buf32 = readl_relaxed(evtq_addr + idx);
+		idx = (idx + 4) & (prestera_fw_evtq_len(fw, qid) - 1);
+	}
+
+	prestera_fw_evtq_rd_set(fw, qid, idx);
+
+	return i;
+}
+
+static u8 prestera_fw_evtq_pick(struct prestera_fw *fw)
+{
+	int qid;
+
+	for (qid = 0; qid < fw->evt_qnum; qid++) {
+		if (prestera_fw_evtq_avail(fw, qid) >= 4)
+			return qid;
+	}
+
+	return PRESTERA_EVT_QNUM_MAX;
+}
+
+static void prestera_fw_evt_work_fn(struct work_struct *work)
+{
+	struct prestera_fw *fw;
+	void *msg;
+	u8 qid;
+
+	fw = container_of(work, struct prestera_fw, evt_work);
+	msg = fw->evt_msg;
+
+	while ((qid = prestera_fw_evtq_pick(fw)) < PRESTERA_EVT_QNUM_MAX) {
+		u32 idx;
+		u32 len;
+
+		len = prestera_fw_evtq_read32(fw, qid);
+		idx = prestera_fw_read(fw, PRESTERA_EVTQ_RD_IDX_REG(qid));
+
+		WARN_ON(prestera_fw_evtq_avail(fw, qid) < len);
+
+		if (WARN_ON(len > PRESTERA_MSG_MAX_SIZE)) {
+			prestera_fw_evtq_rd_set(fw, qid, idx + len);
+			continue;
+		}
+
+		prestera_fw_evtq_read_buf(fw, qid, msg, len);
+
+		if (fw->dev.recv_msg)
+			fw->dev.recv_msg(&fw->dev, msg, len);
+	}
+}
+
+static int prestera_fw_wait_reg32(struct prestera_fw *fw, u32 reg, u32 cmp,
+				  unsigned int waitms)
+{
+	u8 __iomem *addr = PRESTERA_FW_REG_ADDR(fw, reg);
+	u32 val;
+
+	return readl_poll_timeout(addr, val, cmp == val,
+				  1 * USEC_PER_MSEC, waitms * USEC_PER_MSEC);
+}
+
+static int prestera_fw_cmd_send(struct prestera_fw *fw,
+				void *in_msg, size_t in_size,
+				void *out_msg, size_t out_size,
+				unsigned int waitms)
+{
+	u32 ret_size;
+	int err;
+
+	if (!waitms)
+		waitms = PRESTERA_FW_CMD_DEFAULT_WAIT_MS;
+
+	if (ALIGN(in_size, 4) > fw->cmd_mbox_len)
+		return -EMSGSIZE;
+
+	/* wait for finish previous reply from FW */
+	err = prestera_fw_wait_reg32(fw, PRESTERA_CMD_RCV_CTL_REG, 0, 30);
+	if (err) {
+		dev_err(fw->dev.dev, "finish reply from FW is timed out\n");
+		return err;
+	}
+
+	prestera_fw_write(fw, PRESTERA_CMD_REQ_LEN_REG, in_size);
+	memcpy_toio(fw->cmd_mbox, in_msg, in_size);
+
+	prestera_fw_write(fw, PRESTERA_CMD_REQ_CTL_REG, PRESTERA_CMD_F_REQ_SENT);
+
+	/* wait for reply from FW */
+	err = prestera_fw_wait_reg32(fw, PRESTERA_CMD_RCV_CTL_REG,
+				     PRESTERA_CMD_F_REPL_SENT, waitms);
+	if (err) {
+		dev_err(fw->dev.dev, "reply from FW is timed out\n");
+		goto cmd_exit;
+	}
+
+	ret_size = prestera_fw_read(fw, PRESTERA_CMD_RCV_LEN_REG);
+	if (ret_size > out_size) {
+		dev_err(fw->dev.dev, "ret_size (%u) > out_len(%zu)\n",
+			ret_size, out_size);
+		err = -EMSGSIZE;
+		goto cmd_exit;
+	}
+
+	memcpy_fromio(out_msg, fw->cmd_mbox + in_size, ret_size);
+
+cmd_exit:
+	prestera_fw_write(fw, PRESTERA_CMD_REQ_CTL_REG, PRESTERA_CMD_F_REPL_RCVD);
+	return err;
+}
+
+static int prestera_fw_send_req(struct prestera_device *dev,
+				void *in_msg, size_t in_size, void *out_msg,
+				size_t out_size, unsigned int waitms)
+{
+	struct prestera_fw *fw;
+	ssize_t ret;
+
+	fw = container_of(dev, struct prestera_fw, dev);
+
+	mutex_lock(&fw->cmd_mtx);
+	ret = prestera_fw_cmd_send(fw, in_msg, in_size, out_msg, out_size, waitms);
+	mutex_unlock(&fw->cmd_mtx);
+
+	return ret;
+}
+
+static int prestera_fw_init(struct prestera_fw *fw)
+{
+	u8 __iomem *base;
+	int err;
+	u8 qid;
+
+	fw->dev.send_req = prestera_fw_send_req;
+	fw->ldr_regs = fw->dev.ctl_regs;
+
+	err = prestera_fw_load(fw);
+	if (err)
+		return err;
+
+	err = prestera_fw_wait_reg32(fw, PRESTERA_FW_READY_REG,
+				     PRESTERA_FW_READY_MAGIC,
+				     PRESTERA_FW_READY_WAIT_MS);
+	if (err) {
+		dev_err(fw->dev.dev, "FW failed to start\n");
+		return err;
+	}
+
+	base = fw->dev.ctl_regs;
+
+	fw->cmd_mbox = base + prestera_fw_read(fw, PRESTERA_CMD_BUF_OFFS_REG);
+	fw->cmd_mbox_len = prestera_fw_read(fw, PRESTERA_CMD_BUF_LEN_REG);
+	mutex_init(&fw->cmd_mtx);
+
+	fw->evt_buf = base + prestera_fw_read(fw, PRESTERA_EVT_BUF_OFFS_REG);
+	fw->evt_qnum = prestera_fw_read(fw, PRESTERA_EVT_QNUM_REG);
+	fw->evt_msg = kmalloc(PRESTERA_MSG_MAX_SIZE, GFP_KERNEL);
+	if (!fw->evt_msg)
+		return -ENOMEM;
+
+	for (qid = 0; qid < fw->evt_qnum; qid++) {
+		u32 offs = prestera_fw_read(fw, PRESTERA_EVTQ_OFFS_REG(qid));
+		struct prestera_fw_evtq *evtq = &fw->evt_queue[qid];
+
+		evtq->len = prestera_fw_read(fw, PRESTERA_EVTQ_LEN_REG(qid));
+		evtq->addr = fw->evt_buf + offs;
+	}
+
+	return 0;
+}
+
+static void prestera_fw_uninit(struct prestera_fw *fw)
+{
+	kfree(fw->evt_msg);
+}
+
+static irqreturn_t prestera_pci_irq_handler(int irq, void *dev_id)
+{
+	struct prestera_fw *fw = dev_id;
+
+	if (prestera_fw_read(fw, PRESTERA_RX_STATUS_REG)) {
+		prestera_fw_write(fw, PRESTERA_RX_STATUS_REG, 0);
+
+		if (fw->dev.recv_pkt)
+			fw->dev.recv_pkt(&fw->dev);
+	}
+
+	queue_work(fw->wq, &fw->evt_work);
+
+	return IRQ_HANDLED;
+}
+
+static void prestera_ldr_write(struct prestera_fw *fw, u32 reg, u32 val)
+{
+	writel(val, PRESTERA_LDR_REG_ADDR(fw, reg));
+}
+
+static u32 prestera_ldr_read(struct prestera_fw *fw, u32 reg)
+{
+	return readl(PRESTERA_LDR_REG_ADDR(fw, reg));
+}
+
+static int prestera_ldr_wait_reg32(struct prestera_fw *fw,
+				   u32 reg, u32 cmp, unsigned int waitms)
+{
+	u8 __iomem *addr = PRESTERA_LDR_REG_ADDR(fw, reg);
+	u32 val;
+
+	return readl_poll_timeout(addr, val, cmp == val,
+				  10 * USEC_PER_MSEC, waitms * USEC_PER_MSEC);
+}
+
+static u32 prestera_ldr_wait_buf(struct prestera_fw *fw, size_t len)
+{
+	u8 __iomem *addr = PRESTERA_LDR_REG_ADDR(fw, PRESTERA_LDR_BUF_RD_REG);
+	u32 buf_len = fw->ldr_buf_len;
+	u32 wr_idx = fw->ldr_wr_idx;
+	u32 rd_idx;
+
+	return readl_poll_timeout(addr, rd_idx,
+				 CIRC_SPACE(wr_idx, rd_idx, buf_len) >= len,
+				 1 * USEC_PER_MSEC, 100 * USEC_PER_MSEC);
+}
+
+static int prestera_ldr_wait_dl_finish(struct prestera_fw *fw)
+{
+	u8 __iomem *addr = PRESTERA_LDR_REG_ADDR(fw, PRESTERA_LDR_STATUS_REG);
+	unsigned long mask = ~(PRESTERA_LDR_STATUS_IMG_DL);
+	u32 val;
+	int err;
+
+	err = readl_poll_timeout(addr, val, val & mask, 10 * USEC_PER_MSEC,
+				 PRESTERA_FW_DL_TIMEOUT_MS * USEC_PER_MSEC);
+	if (err) {
+		dev_err(fw->dev.dev, "Timeout to load FW img [state=%d]",
+			prestera_ldr_read(fw, PRESTERA_LDR_STATUS_REG));
+		return err;
+	}
+
+	return 0;
+}
+
+static void prestera_ldr_wr_idx_move(struct prestera_fw *fw, unsigned int n)
+{
+	fw->ldr_wr_idx = (fw->ldr_wr_idx + (n)) & (fw->ldr_buf_len - 1);
+}
+
+static void prestera_ldr_wr_idx_commit(struct prestera_fw *fw)
+{
+	prestera_ldr_write(fw, PRESTERA_LDR_BUF_WR_REG, fw->ldr_wr_idx);
+}
+
+static u8 __iomem *prestera_ldr_wr_ptr(struct prestera_fw *fw)
+{
+	return fw->ldr_ring_buf + fw->ldr_wr_idx;
+}
+
+static int prestera_ldr_send(struct prestera_fw *fw, const u8 *buf, size_t len)
+{
+	int err;
+	int i;
+
+	err = prestera_ldr_wait_buf(fw, len);
+	if (err) {
+		dev_err(fw->dev.dev, "failed wait for sending firmware\n");
+		return err;
+	}
+
+	for (i = 0; i < len; i += 4) {
+		writel_relaxed(*(u32 *)(buf + i), prestera_ldr_wr_ptr(fw));
+		prestera_ldr_wr_idx_move(fw, 4);
+	}
+
+	prestera_ldr_wr_idx_commit(fw);
+	return 0;
+}
+
+static int prestera_ldr_fw_send(struct prestera_fw *fw,
+				const char *img, u32 fw_size)
+{
+	u32 status;
+	u32 pos;
+	int err;
+
+	err = prestera_ldr_wait_reg32(fw, PRESTERA_LDR_STATUS_REG,
+				      PRESTERA_LDR_STATUS_IMG_DL,
+				      5 * MSEC_PER_SEC);
+	if (err) {
+		dev_err(fw->dev.dev, "Loader is not ready to load image\n");
+		return err;
+	}
+
+	for (pos = 0; pos < fw_size; pos += PRESTERA_FW_BLK_SZ) {
+		if (pos + PRESTERA_FW_BLK_SZ > fw_size)
+			break;
+
+		err = prestera_ldr_send(fw, img + pos, PRESTERA_FW_BLK_SZ);
+		if (err)
+			return err;
+	}
+
+	if (pos < fw_size) {
+		err = prestera_ldr_send(fw, img + pos, fw_size - pos);
+		if (err)
+			return err;
+	}
+
+	err = prestera_ldr_wait_dl_finish(fw);
+	if (err)
+		return err;
+
+	status = prestera_ldr_read(fw, PRESTERA_LDR_STATUS_REG);
+
+	switch (status) {
+	case PRESTERA_LDR_STATUS_INVALID_IMG:
+		dev_err(fw->dev.dev, "FW img has bad CRC\n");
+		return -EINVAL;
+	case PRESTERA_LDR_STATUS_NOMEM:
+		dev_err(fw->dev.dev, "Loader has no enough mem\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+static void prestera_fw_rev_parse(const struct prestera_fw_header *hdr,
+				  struct prestera_fw_rev *rev)
+{
+	u32 version = be32_to_cpu(hdr->version_value);
+
+	rev->maj = PRESTERA_FW_VER_MAJ(version);
+	rev->min = PRESTERA_FW_VER_MIN(version);
+	rev->sub = PRESTERA_FW_VER_PATCH(version);
+}
+
+static int prestera_fw_rev_check(struct prestera_fw *fw)
+{
+	struct prestera_fw_rev *rev = &fw->dev.fw_rev;
+	u16 maj_supp = PRESTERA_SUPP_FW_MAJ_VER;
+	u16 min_supp = PRESTERA_SUPP_FW_MIN_VER;
+
+	if (rev->maj == maj_supp && rev->min >= min_supp)
+		return 0;
+
+	dev_err(fw->dev.dev, "Driver supports FW version only '%u.%u.x'",
+		PRESTERA_SUPP_FW_MAJ_VER, PRESTERA_SUPP_FW_MIN_VER);
+
+	return -EINVAL;
+}
+
+static int prestera_fw_hdr_parse(struct prestera_fw *fw,
+				 const struct firmware *img)
+{
+	struct prestera_fw_header *hdr = (struct prestera_fw_header *)img->data;
+	struct prestera_fw_rev *rev = &fw->dev.fw_rev;
+	u32 magic;
+
+	magic = be32_to_cpu(hdr->magic_number);
+	if (magic != PRESTERA_FW_HDR_MAGIC) {
+		dev_err(fw->dev.dev, "FW img hdr magic is invalid");
+		return -EINVAL;
+	}
+
+	prestera_fw_rev_parse(hdr, rev);
+
+	dev_info(fw->dev.dev, "FW version '%u.%u.%u'\n",
+		 rev->maj, rev->min, rev->sub);
+
+	return prestera_fw_rev_check(fw);
+}
+
+static int prestera_fw_load(struct prestera_fw *fw)
+{
+	size_t hlen = sizeof(struct prestera_fw_header);
+	const struct firmware *f;
+	char fw_path[128];
+	int err;
+
+	err = prestera_ldr_wait_reg32(fw, PRESTERA_LDR_READY_REG,
+				      PRESTERA_LDR_READY_MAGIC,
+				      5 * MSEC_PER_SEC);
+	if (err) {
+		dev_err(fw->dev.dev, "waiting for FW loader is timed out");
+		return err;
+	}
+
+	fw->ldr_ring_buf = fw->ldr_regs +
+		prestera_ldr_read(fw, PRESTERA_LDR_BUF_OFFS_REG);
+
+	fw->ldr_buf_len =
+		prestera_ldr_read(fw, PRESTERA_LDR_BUF_SIZE_REG);
+
+	fw->ldr_wr_idx = 0;
+
+	snprintf(fw_path, sizeof(fw_path), PRESTERA_FW_PATH_FMT,
+		 PRESTERA_SUPP_FW_MAJ_VER, PRESTERA_SUPP_FW_MIN_VER);
+
+	err = request_firmware_direct(&f, fw_path, fw->dev.dev);
+	if (err) {
+		dev_err(fw->dev.dev, "failed to request firmware file\n");
+		return err;
+	}
+
+	err = prestera_fw_hdr_parse(fw, f);
+	if (err) {
+		dev_err(fw->dev.dev, "FW image header is invalid\n");
+		goto out_release;
+	}
+
+	prestera_ldr_write(fw, PRESTERA_LDR_IMG_SIZE_REG, f->size - hlen);
+	prestera_ldr_write(fw, PRESTERA_LDR_CTL_REG, PRESTERA_LDR_CTL_DL_START);
+
+	dev_info(fw->dev.dev, "Loading %s ...", fw_path);
+
+	err = prestera_ldr_fw_send(fw, f->data + hlen, f->size - hlen);
+
+out_release:
+	release_firmware(f);
+	return err;
+}
+
+static int prestera_pci_probe(struct pci_dev *pdev,
+			      const struct pci_device_id *id)
+{
+	const char *driver_name = pdev->driver->name;
+	struct prestera_fw *fw;
+	int err;
+
+	err = pcim_enable_device(pdev);
+	if (err)
+		return err;
+
+	err = pcim_iomap_regions(pdev, BIT(PRESTERA_PCI_BAR_FW) |
+				 BIT(PRESTERA_PCI_BAR_PP),
+				 pci_name(pdev));
+	if (err)
+		return err;
+
+	if (dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(30))) {
+		dev_err(&pdev->dev, "fail to set DMA mask\n");
+		goto err_dma_mask;
+	}
+
+	pci_set_master(pdev);
+
+	fw = devm_kzalloc(&pdev->dev, sizeof(*fw), GFP_KERNEL);
+	if (!fw) {
+		err = -ENOMEM;
+		goto err_pci_dev_alloc;
+	}
+
+	fw->dev.ctl_regs = pcim_iomap_table(pdev)[PRESTERA_PCI_BAR_FW];
+	fw->dev.pp_regs = pcim_iomap_table(pdev)[PRESTERA_PCI_BAR_PP];
+	fw->dev.dev = &pdev->dev;
+
+	pci_set_drvdata(pdev, fw);
+
+	err = prestera_fw_init(fw);
+	if (err)
+		goto err_prestera_fw_init;
+
+	dev_info(fw->dev.dev, "Prestera FW is ready\n");
+
+	fw->wq = alloc_workqueue("prestera_fw_wq", WQ_HIGHPRI, 1);
+	if (!fw->wq)
+		goto err_wq_alloc;
+
+	INIT_WORK(&fw->evt_work, prestera_fw_evt_work_fn);
+
+	err = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_MSI);
+	if (err < 0) {
+		dev_err(&pdev->dev, "MSI IRQ init failed\n");
+		goto err_irq_alloc;
+	}
+
+	err = request_irq(pci_irq_vector(pdev, 0), prestera_pci_irq_handler,
+			  0, driver_name, fw);
+	if (err) {
+		dev_err(&pdev->dev, "fail to request IRQ\n");
+		goto err_request_irq;
+	}
+
+	err = prestera_device_register(&fw->dev);
+	if (err)
+		goto err_prestera_dev_register;
+
+	return 0;
+
+err_prestera_dev_register:
+	free_irq(pci_irq_vector(pdev, 0), fw);
+err_request_irq:
+	pci_free_irq_vectors(pdev);
+err_irq_alloc:
+	destroy_workqueue(fw->wq);
+err_wq_alloc:
+	prestera_fw_uninit(fw);
+err_prestera_fw_init:
+err_pci_dev_alloc:
+err_dma_mask:
+	return err;
+}
+
+static void prestera_pci_remove(struct pci_dev *pdev)
+{
+	struct prestera_fw *fw = pci_get_drvdata(pdev);
+
+	prestera_device_unregister(&fw->dev);
+	free_irq(pci_irq_vector(pdev, 0), fw);
+	pci_free_irq_vectors(pdev);
+	destroy_workqueue(fw->wq);
+	prestera_fw_uninit(fw);
+}
+
+static const struct pci_device_id prestera_pci_devices[] = {
+	{ PCI_DEVICE(PCI_VENDOR_ID_MARVELL, 0xC804) },
+	{ }
+};
+MODULE_DEVICE_TABLE(pci, prestera_pci_devices);
+
+static struct pci_driver prestera_pci_driver = {
+	.name     = "Prestera DX",
+	.id_table = prestera_pci_devices,
+	.probe    = prestera_pci_probe,
+	.remove   = prestera_pci_remove,
+};
+module_pci_driver(prestera_pci_driver);
+
+MODULE_LICENSE("Dual BSD/GPL");
+MODULE_DESCRIPTION("Marvell Prestera switch PCI interface");