/*
 * Copyright (c) Atmel Corporation.  All rights reserved.
 *
 * Module Name:  wilc_spi.c
 */

#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/cdev.h>
#include <linux/uaccess.h>
#include <linux/device.h>
#include <linux/spi/spi.h>
#include <linux/of_gpio.h>

#include <linux/string.h>
#include "wilc_wlan_if.h"
#include "wilc_wlan.h"
#include "wilc_wfi_netdevice.h"

struct wilc_spi {
	int crc_off;
	int nint;
	int has_thrpt_enh;
};

static struct wilc_spi g_spi;
static const struct wilc_hif_func wilc_hif_spi;

static int wilc_spi_read(struct wilc *wilc, u32, u8 *, u32);
static int wilc_spi_write(struct wilc *wilc, u32, u8 *, u32);

/********************************************
 *
 *      Crc7
 *
 ********************************************/

static const u8 crc7_syndrome_table[256] = {
	0x00, 0x09, 0x12, 0x1b, 0x24, 0x2d, 0x36, 0x3f,
	0x48, 0x41, 0x5a, 0x53, 0x6c, 0x65, 0x7e, 0x77,
	0x19, 0x10, 0x0b, 0x02, 0x3d, 0x34, 0x2f, 0x26,
	0x51, 0x58, 0x43, 0x4a, 0x75, 0x7c, 0x67, 0x6e,
	0x32, 0x3b, 0x20, 0x29, 0x16, 0x1f, 0x04, 0x0d,
	0x7a, 0x73, 0x68, 0x61, 0x5e, 0x57, 0x4c, 0x45,
	0x2b, 0x22, 0x39, 0x30, 0x0f, 0x06, 0x1d, 0x14,
	0x63, 0x6a, 0x71, 0x78, 0x47, 0x4e, 0x55, 0x5c,
	0x64, 0x6d, 0x76, 0x7f, 0x40, 0x49, 0x52, 0x5b,
	0x2c, 0x25, 0x3e, 0x37, 0x08, 0x01, 0x1a, 0x13,
	0x7d, 0x74, 0x6f, 0x66, 0x59, 0x50, 0x4b, 0x42,
	0x35, 0x3c, 0x27, 0x2e, 0x11, 0x18, 0x03, 0x0a,
	0x56, 0x5f, 0x44, 0x4d, 0x72, 0x7b, 0x60, 0x69,
	0x1e, 0x17, 0x0c, 0x05, 0x3a, 0x33, 0x28, 0x21,
	0x4f, 0x46, 0x5d, 0x54, 0x6b, 0x62, 0x79, 0x70,
	0x07, 0x0e, 0x15, 0x1c, 0x23, 0x2a, 0x31, 0x38,
	0x41, 0x48, 0x53, 0x5a, 0x65, 0x6c, 0x77, 0x7e,
	0x09, 0x00, 0x1b, 0x12, 0x2d, 0x24, 0x3f, 0x36,
	0x58, 0x51, 0x4a, 0x43, 0x7c, 0x75, 0x6e, 0x67,
	0x10, 0x19, 0x02, 0x0b, 0x34, 0x3d, 0x26, 0x2f,
	0x73, 0x7a, 0x61, 0x68, 0x57, 0x5e, 0x45, 0x4c,
	0x3b, 0x32, 0x29, 0x20, 0x1f, 0x16, 0x0d, 0x04,
	0x6a, 0x63, 0x78, 0x71, 0x4e, 0x47, 0x5c, 0x55,
	0x22, 0x2b, 0x30, 0x39, 0x06, 0x0f, 0x14, 0x1d,
	0x25, 0x2c, 0x37, 0x3e, 0x01, 0x08, 0x13, 0x1a,
	0x6d, 0x64, 0x7f, 0x76, 0x49, 0x40, 0x5b, 0x52,
	0x3c, 0x35, 0x2e, 0x27, 0x18, 0x11, 0x0a, 0x03,
	0x74, 0x7d, 0x66, 0x6f, 0x50, 0x59, 0x42, 0x4b,
	0x17, 0x1e, 0x05, 0x0c, 0x33, 0x3a, 0x21, 0x28,
	0x5f, 0x56, 0x4d, 0x44, 0x7b, 0x72, 0x69, 0x60,
	0x0e, 0x07, 0x1c, 0x15, 0x2a, 0x23, 0x38, 0x31,
	0x46, 0x4f, 0x54, 0x5d, 0x62, 0x6b, 0x70, 0x79
};

static u8 crc7_byte(u8 crc, u8 data)
{
	return crc7_syndrome_table[(crc << 1) ^ data];
}

static u8 crc7(u8 crc, const u8 *buffer, u32 len)
{
	while (len--)
		crc = crc7_byte(crc, *buffer++);
	return crc;
}

/********************************************
 *
 *      Spi protocol Function
 *
 ********************************************/

#define CMD_DMA_WRITE				0xc1
#define CMD_DMA_READ				0xc2
#define CMD_INTERNAL_WRITE		0xc3
#define CMD_INTERNAL_READ		0xc4
#define CMD_TERMINATE				0xc5
#define CMD_REPEAT					0xc6
#define CMD_DMA_EXT_WRITE		0xc7
#define CMD_DMA_EXT_READ		0xc8
#define CMD_SINGLE_WRITE			0xc9
#define CMD_SINGLE_READ			0xca
#define CMD_RESET						0xcf

#define N_OK								1
#define N_FAIL								0
#define N_RESET							-1
#define N_RETRY							-2

#define DATA_PKT_SZ_256				256
#define DATA_PKT_SZ_512			512
#define DATA_PKT_SZ_1K				1024
#define DATA_PKT_SZ_4K				(4 * 1024)
#define DATA_PKT_SZ_8K				(8 * 1024)
#define DATA_PKT_SZ					DATA_PKT_SZ_8K

#define USE_SPI_DMA     0

static int wilc_bus_probe(struct spi_device *spi)
{
	int ret, gpio;
	struct wilc *wilc;

	gpio = of_get_gpio(spi->dev.of_node, 0);
	if (gpio < 0)
		gpio = GPIO_NUM;

	ret = wilc_netdev_init(&wilc, NULL, HIF_SPI, GPIO_NUM, &wilc_hif_spi);
	if (ret)
		return ret;

	spi_set_drvdata(spi, wilc);
	wilc->dev = &spi->dev;

	return 0;
}

static int wilc_bus_remove(struct spi_device *spi)
{
	wilc_netdev_cleanup(spi_get_drvdata(spi));
	return 0;
}

static const struct of_device_id wilc1000_of_match[] = {
	{ .compatible = "atmel,wilc_spi", },
	{}
};
MODULE_DEVICE_TABLE(of, wilc1000_of_match);

static struct spi_driver wilc1000_spi_driver = {
	.driver = {
		.name = MODALIAS,
		.of_match_table = wilc1000_of_match,
	},
	.probe =  wilc_bus_probe,
	.remove = wilc_bus_remove,
};
module_spi_driver(wilc1000_spi_driver);
MODULE_LICENSE("GPL");

static int wilc_spi_tx(struct wilc *wilc, u8 *b, u32 len)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	int ret;
	struct spi_message msg;

	if (len > 0 && b) {
		struct spi_transfer tr = {
			.tx_buf = b,
			.len = len,
			.delay_usecs = 0,
		};
		char *r_buffer = kzalloc(len, GFP_KERNEL);

		if (!r_buffer)
			return -ENOMEM;

		tr.rx_buf = r_buffer;
		dev_dbg(&spi->dev, "Request writing %d bytes\n", len);

		memset(&msg, 0, sizeof(msg));
		spi_message_init(&msg);
		msg.spi = spi;
		msg.is_dma_mapped = USE_SPI_DMA;
		spi_message_add_tail(&tr, &msg);

		ret = spi_sync(spi, &msg);
		if (ret < 0)
			dev_err(&spi->dev, "SPI transaction failed\n");

		kfree(r_buffer);
	} else {
		dev_err(&spi->dev,
			"can't write data with the following length: %d\n",
			len);
		ret = -EINVAL;
	}

	return ret;
}

static int wilc_spi_rx(struct wilc *wilc, u8 *rb, u32 rlen)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	int ret;

	if (rlen > 0) {
		struct spi_message msg;
		struct spi_transfer tr = {
			.rx_buf = rb,
			.len = rlen,
			.delay_usecs = 0,

		};
		char *t_buffer = kzalloc(rlen, GFP_KERNEL);

		if (!t_buffer)
			return -ENOMEM;

		tr.tx_buf = t_buffer;

		memset(&msg, 0, sizeof(msg));
		spi_message_init(&msg);
		msg.spi = spi;
		msg.is_dma_mapped = USE_SPI_DMA;
		spi_message_add_tail(&tr, &msg);

		ret = spi_sync(spi, &msg);
		if (ret < 0)
			dev_err(&spi->dev, "SPI transaction failed\n");
		kfree(t_buffer);
	} else {
		dev_err(&spi->dev,
			"can't read data with the following length: %u\n",
			rlen);
		ret = -EINVAL;
	}

	return ret;
}

static int wilc_spi_tx_rx(struct wilc *wilc, u8 *wb, u8 *rb, u32 rlen)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	int ret;

	if (rlen > 0) {
		struct spi_message msg;
		struct spi_transfer tr = {
			.rx_buf = rb,
			.tx_buf = wb,
			.len = rlen,
			.bits_per_word = 8,
			.delay_usecs = 0,

		};

		memset(&msg, 0, sizeof(msg));
		spi_message_init(&msg);
		msg.spi = spi;
		msg.is_dma_mapped = USE_SPI_DMA;

		spi_message_add_tail(&tr, &msg);
		ret = spi_sync(spi, &msg);
		if (ret < 0)
			dev_err(&spi->dev, "SPI transaction failed\n");
	} else {
		dev_err(&spi->dev,
			"can't read data with the following length: %u\n",
			rlen);
		ret = -EINVAL;
	}

	return ret;
}

static int spi_cmd_complete(struct wilc *wilc, u8 cmd, u32 adr, u8 *b, u32 sz,
			    u8 clockless)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	u8 wb[32], rb[32];
	u8 wix, rix;
	u32 len2;
	u8 rsp;
	int len = 0;
	int result = N_OK;

	wb[0] = cmd;
	switch (cmd) {
	case CMD_SINGLE_READ:                           /* single word (4 bytes) read */
		wb[1] = (u8)(adr >> 16);
		wb[2] = (u8)(adr >> 8);
		wb[3] = (u8)adr;
		len = 5;
		break;

	case CMD_INTERNAL_READ:                 /* internal register read */
		wb[1] = (u8)(adr >> 8);
		if (clockless == 1)
			wb[1] |= BIT(7);
		wb[2] = (u8)adr;
		wb[3] = 0x00;
		len = 5;
		break;

	case CMD_TERMINATE:                                     /* termination */
		wb[1] = 0x00;
		wb[2] = 0x00;
		wb[3] = 0x00;
		len = 5;
		break;

	case CMD_REPEAT:                                                /* repeat */
		wb[1] = 0x00;
		wb[2] = 0x00;
		wb[3] = 0x00;
		len = 5;
		break;

	case CMD_RESET:                                                 /* reset */
		wb[1] = 0xff;
		wb[2] = 0xff;
		wb[3] = 0xff;
		len = 5;
		break;

	case CMD_DMA_WRITE:                                     /* dma write */
	case CMD_DMA_READ:                                      /* dma read */
		wb[1] = (u8)(adr >> 16);
		wb[2] = (u8)(adr >> 8);
		wb[3] = (u8)adr;
		wb[4] = (u8)(sz >> 8);
		wb[5] = (u8)(sz);
		len = 7;
		break;

	case CMD_DMA_EXT_WRITE:         /* dma extended write */
	case CMD_DMA_EXT_READ:                  /* dma extended read */
		wb[1] = (u8)(adr >> 16);
		wb[2] = (u8)(adr >> 8);
		wb[3] = (u8)adr;
		wb[4] = (u8)(sz >> 16);
		wb[5] = (u8)(sz >> 8);
		wb[6] = (u8)(sz);
		len = 8;
		break;

	case CMD_INTERNAL_WRITE:                /* internal register write */
		wb[1] = (u8)(adr >> 8);
		if (clockless == 1)
			wb[1] |= BIT(7);
		wb[2] = (u8)(adr);
		wb[3] = b[3];
		wb[4] = b[2];
		wb[5] = b[1];
		wb[6] = b[0];
		len = 8;
		break;

	case CMD_SINGLE_WRITE:                  /* single word write */
		wb[1] = (u8)(adr >> 16);
		wb[2] = (u8)(adr >> 8);
		wb[3] = (u8)(adr);
		wb[4] = b[3];
		wb[5] = b[2];
		wb[6] = b[1];
		wb[7] = b[0];
		len = 9;
		break;

	default:
		result = N_FAIL;
		break;
	}

	if (result != N_OK)
		return result;

	if (!g_spi.crc_off)
		wb[len - 1] = (crc7(0x7f, (const u8 *)&wb[0], len - 1)) << 1;
	else
		len -= 1;

#define NUM_SKIP_BYTES (1)
#define NUM_RSP_BYTES (2)
#define NUM_DATA_HDR_BYTES (1)
#define NUM_DATA_BYTES (4)
#define NUM_CRC_BYTES (2)
#define NUM_DUMMY_BYTES (3)
	if ((cmd == CMD_RESET) ||
	    (cmd == CMD_TERMINATE) ||
	    (cmd == CMD_REPEAT)) {
		len2 = len + (NUM_SKIP_BYTES + NUM_RSP_BYTES + NUM_DUMMY_BYTES);
	} else if ((cmd == CMD_INTERNAL_READ) || (cmd == CMD_SINGLE_READ)) {
		if (!g_spi.crc_off) {
			len2 = len + (NUM_RSP_BYTES + NUM_DATA_HDR_BYTES + NUM_DATA_BYTES
				      + NUM_CRC_BYTES + NUM_DUMMY_BYTES);
		} else {
			len2 = len + (NUM_RSP_BYTES + NUM_DATA_HDR_BYTES + NUM_DATA_BYTES
				      + NUM_DUMMY_BYTES);
		}
	} else {
		len2 = len + (NUM_RSP_BYTES + NUM_DUMMY_BYTES);
	}
#undef NUM_DUMMY_BYTES

	if (len2 > ARRAY_SIZE(wb)) {
		dev_err(&spi->dev, "spi buffer size too small (%d) (%zu)\n",
			len2, ARRAY_SIZE(wb));
		return N_FAIL;
	}
	/* zero spi write buffers. */
	for (wix = len; wix < len2; wix++)
		wb[wix] = 0;
	rix = len;

	if (wilc_spi_tx_rx(wilc, wb, rb, len2)) {
		dev_err(&spi->dev, "Failed cmd write, bus error...\n");
		return N_FAIL;
	}

	/**
	 * Command/Control response
	 **/
	if ((cmd == CMD_RESET) ||
	    (cmd == CMD_TERMINATE) ||
	    (cmd == CMD_REPEAT)) {
		rix++;         /* skip 1 byte */
	}

	/* do { */
	rsp = rb[rix++];
	/*	if(rsp == cmd) break; */
	/* } while(&rptr[1] <= &rb[len2]); */

	if (rsp != cmd) {
		dev_err(&spi->dev,
			"Failed cmd response, cmd (%02x), resp (%02x)\n",
			cmd, rsp);
		return N_FAIL;
	}

	/**
	 * State response
	 **/
	rsp = rb[rix++];
	if (rsp != 0x00) {
		dev_err(&spi->dev, "Failed cmd state response state (%02x)\n",
			rsp);
		return N_FAIL;
	}

	if ((cmd == CMD_INTERNAL_READ) || (cmd == CMD_SINGLE_READ) ||
	    (cmd == CMD_DMA_READ) || (cmd == CMD_DMA_EXT_READ)) {
		int retry;
		/* u16 crc1, crc2; */
		u8 crc[2];
		/**
		 * Data Respnose header
		 **/
		retry = 100;
		do {
			/* ensure there is room in buffer later to read data and crc */
			if (rix < len2) {
				rsp = rb[rix++];
			} else {
				retry = 0;
				break;
			}
			if (((rsp >> 4) & 0xf) == 0xf)
				break;
		} while (retry--);

		if (retry <= 0) {
			dev_err(&spi->dev,
				"Error, data read response (%02x)\n", rsp);
			return N_RESET;
		}

		if ((cmd == CMD_INTERNAL_READ) || (cmd == CMD_SINGLE_READ)) {
			/**
			 * Read bytes
			 **/
			if ((rix + 3) < len2) {
				b[0] = rb[rix++];
				b[1] = rb[rix++];
				b[2] = rb[rix++];
				b[3] = rb[rix++];
			} else {
				dev_err(&spi->dev,
					"buffer overrun when reading data.\n");
				return N_FAIL;
			}

			if (!g_spi.crc_off) {
				/**
				 * Read Crc
				 **/
				if ((rix + 1) < len2) {
					crc[0] = rb[rix++];
					crc[1] = rb[rix++];
				} else {
					dev_err(&spi->dev, "buffer overrun when reading crc.\n");
					return N_FAIL;
				}
			}
		} else if ((cmd == CMD_DMA_READ) || (cmd == CMD_DMA_EXT_READ)) {
			int ix;

			/* some data may be read in response to dummy bytes. */
			for (ix = 0; (rix < len2) && (ix < sz); )
				b[ix++] = rb[rix++];

			sz -= ix;

			if (sz > 0) {
				int nbytes;

				if (sz <= (DATA_PKT_SZ - ix))
					nbytes = sz;
				else
					nbytes = DATA_PKT_SZ - ix;

				/**
				 * Read bytes
				 **/
				if (wilc_spi_rx(wilc, &b[ix], nbytes)) {
					dev_err(&spi->dev, "Failed data block read, bus error...\n");
					result = N_FAIL;
					goto _error_;
				}

				/**
				 * Read Crc
				 **/
				if (!g_spi.crc_off) {
					if (wilc_spi_rx(wilc, crc, 2)) {
						dev_err(&spi->dev, "Failed data block crc read, bus error...\n");
						result = N_FAIL;
						goto _error_;
					}
				}

				ix += nbytes;
				sz -= nbytes;
			}

			/*  if any data in left unread, then read the rest using normal DMA code.*/
			while (sz > 0) {
				int nbytes;

				if (sz <= DATA_PKT_SZ)
					nbytes = sz;
				else
					nbytes = DATA_PKT_SZ;

				/**
				 * read data response only on the next DMA cycles not
				 * the first DMA since data response header is already
				 * handled above for the first DMA.
				 **/
				/**
				 * Data Respnose header
				 **/
				retry = 10;
				do {
					if (wilc_spi_rx(wilc, &rsp, 1)) {
						dev_err(&spi->dev, "Failed data response read, bus error...\n");
						result = N_FAIL;
						break;
					}
					if (((rsp >> 4) & 0xf) == 0xf)
						break;
				} while (retry--);

				if (result == N_FAIL)
					break;

				/**
				 * Read bytes
				 **/
				if (wilc_spi_rx(wilc, &b[ix], nbytes)) {
					dev_err(&spi->dev, "Failed data block read, bus error...\n");
					result = N_FAIL;
					break;
				}

				/**
				 * Read Crc
				 **/
				if (!g_spi.crc_off) {
					if (wilc_spi_rx(wilc, crc, 2)) {
						dev_err(&spi->dev, "Failed data block crc read, bus error...\n");
						result = N_FAIL;
						break;
					}
				}

				ix += nbytes;
				sz -= nbytes;
			}
		}
	}
_error_:
	return result;
}

static int spi_data_write(struct wilc *wilc, u8 *b, u32 sz)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	int ix, nbytes;
	int result = 1;
	u8 cmd, order, crc[2] = {0};
	/* u8 rsp; */

	/**
	 *      Data
	 **/
	ix = 0;
	do {
		if (sz <= DATA_PKT_SZ)
			nbytes = sz;
		else
			nbytes = DATA_PKT_SZ;

		/**
		 *      Write command
		 **/
		cmd = 0xf0;
		if (ix == 0) {
			if (sz <= DATA_PKT_SZ)

				order = 0x3;
			else
				order = 0x1;
		} else {
			if (sz <= DATA_PKT_SZ)
				order = 0x3;
			else
				order = 0x2;
		}
		cmd |= order;
		if (wilc_spi_tx(wilc, &cmd, 1)) {
			dev_err(&spi->dev,
				"Failed data block cmd write, bus error...\n");
			result = N_FAIL;
			break;
		}

		/**
		 *      Write data
		 **/
		if (wilc_spi_tx(wilc, &b[ix], nbytes)) {
			dev_err(&spi->dev,
				"Failed data block write, bus error...\n");
			result = N_FAIL;
			break;
		}

		/**
		 *      Write Crc
		 **/
		if (!g_spi.crc_off) {
			if (wilc_spi_tx(wilc, crc, 2)) {
				dev_err(&spi->dev, "Failed data block crc write, bus error...\n");
				result = N_FAIL;
				break;
			}
		}

		/**
		 *      No need to wait for response
		 **/
		ix += nbytes;
		sz -= nbytes;
	} while (sz);

	return result;
}

/********************************************
 *
 *      Spi Internal Read/Write Function
 *
 ********************************************/

static int spi_internal_write(struct wilc *wilc, u32 adr, u32 dat)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	int result;

	dat = cpu_to_le32(dat);
	result = spi_cmd_complete(wilc, CMD_INTERNAL_WRITE, adr, (u8 *)&dat, 4,
				  0);
	if (result != N_OK)
		dev_err(&spi->dev, "Failed internal write cmd...\n");

	return result;
}

static int spi_internal_read(struct wilc *wilc, u32 adr, u32 *data)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	int result;

	result = spi_cmd_complete(wilc, CMD_INTERNAL_READ, adr, (u8 *)data, 4,
				  0);
	if (result != N_OK) {
		dev_err(&spi->dev, "Failed internal read cmd...\n");
		return 0;
	}

	*data = cpu_to_le32(*data);

	return 1;
}

/********************************************
 *
 *      Spi interfaces
 *
 ********************************************/

static int wilc_spi_write_reg(struct wilc *wilc, u32 addr, u32 data)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	int result = N_OK;
	u8 cmd = CMD_SINGLE_WRITE;
	u8 clockless = 0;

	data = cpu_to_le32(data);
	if (addr < 0x30) {
		/* Clockless register*/
		cmd = CMD_INTERNAL_WRITE;
		clockless = 1;
	}

	result = spi_cmd_complete(wilc, cmd, addr, (u8 *)&data, 4, clockless);
	if (result != N_OK)
		dev_err(&spi->dev, "Failed cmd, write reg (%08x)...\n", addr);

	return result;
}

static int wilc_spi_write(struct wilc *wilc, u32 addr, u8 *buf, u32 size)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	int result;
	u8 cmd = CMD_DMA_EXT_WRITE;

	/**
	 *      has to be greated than 4
	 **/
	if (size <= 4)
		return 0;

	result = spi_cmd_complete(wilc, cmd, addr, NULL, size, 0);
	if (result != N_OK) {
		dev_err(&spi->dev,
			"Failed cmd, write block (%08x)...\n", addr);
		return 0;
	}

	/**
	 *      Data
	 **/
	result = spi_data_write(wilc, buf, size);
	if (result != N_OK)
		dev_err(&spi->dev, "Failed block data write...\n");

	return 1;
}

static int wilc_spi_read_reg(struct wilc *wilc, u32 addr, u32 *data)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	int result = N_OK;
	u8 cmd = CMD_SINGLE_READ;
	u8 clockless = 0;

	if (addr < 0x30) {
		/* dev_err(&spi->dev, "***** read addr %d\n\n", addr); */
		/* Clockless register*/
		cmd = CMD_INTERNAL_READ;
		clockless = 1;
	}

	result = spi_cmd_complete(wilc, cmd, addr, (u8 *)data, 4, clockless);
	if (result != N_OK) {
		dev_err(&spi->dev, "Failed cmd, read reg (%08x)...\n", addr);
		return 0;
	}

	*data = cpu_to_le32(*data);

	return 1;
}

static int wilc_spi_read(struct wilc *wilc, u32 addr, u8 *buf, u32 size)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	u8 cmd = CMD_DMA_EXT_READ;
	int result;

	if (size <= 4)
		return 0;

	result = spi_cmd_complete(wilc, cmd, addr, buf, size, 0);
	if (result != N_OK) {
		dev_err(&spi->dev, "Failed cmd, read block (%08x)...\n", addr);
		return 0;
	}

	return 1;
}

/********************************************
 *
 *      Bus interfaces
 *
 ********************************************/

static int _wilc_spi_deinit(struct wilc *wilc)
{
	/**
	 *      TODO:
	 **/
	return 1;
}

static int wilc_spi_init(struct wilc *wilc, bool resume)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	u32 reg;
	u32 chipid;

	static int isinit;

	if (isinit) {
		if (!wilc_spi_read_reg(wilc, 0x1000, &chipid)) {
			dev_err(&spi->dev, "Fail cmd read chip id...\n");
			return 0;
		}
		return 1;
	}

	memset(&g_spi, 0, sizeof(struct wilc_spi));

	/**
	 *      configure protocol
	 **/
	g_spi.crc_off = 0;

	/* TODO: We can remove the CRC trials if there is a definite way to reset */
	/* the SPI to it's initial value. */
	if (!spi_internal_read(wilc, WILC_SPI_PROTOCOL_OFFSET, &reg)) {
		/* Read failed. Try with CRC off. This might happen when module
		 * is removed but chip isn't reset
		 */
		g_spi.crc_off = 1;
		dev_err(&spi->dev, "Failed internal read protocol with CRC on, retrying with CRC off...\n");
		if (!spi_internal_read(wilc, WILC_SPI_PROTOCOL_OFFSET, &reg)) {
			/* Reaad failed with both CRC on and off, something went bad */
			dev_err(&spi->dev,
				"Failed internal read protocol...\n");
			return 0;
		}
	}
	if (g_spi.crc_off == 0)	{
		reg &= ~0xc;    /* disable crc checking */
		reg &= ~0x70;
		reg |= (0x5 << 4);
		if (!spi_internal_write(wilc, WILC_SPI_PROTOCOL_OFFSET, reg)) {
			dev_err(&spi->dev, "[wilc spi %d]: Failed internal write protocol reg...\n", __LINE__);
			return 0;
		}
		g_spi.crc_off = 1;
	}

	/**
	 *      make sure can read back chip id correctly
	 **/
	if (!wilc_spi_read_reg(wilc, 0x1000, &chipid)) {
		dev_err(&spi->dev, "Fail cmd read chip id...\n");
		return 0;
	}
	/* dev_err(&spi->dev, "chipid (%08x)\n", chipid); */

	g_spi.has_thrpt_enh = 1;

	isinit = 1;

	return 1;
}

static int wilc_spi_read_size(struct wilc *wilc, u32 *size)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	int ret;

	if (g_spi.has_thrpt_enh) {
		ret = spi_internal_read(wilc, 0xe840 - WILC_SPI_REG_BASE,
					size);
		*size = *size  & IRQ_DMA_WD_CNT_MASK;
	} else {
		u32 tmp;
		u32 byte_cnt;

		ret = wilc_spi_read_reg(wilc, WILC_VMM_TO_HOST_SIZE,
					&byte_cnt);
		if (!ret) {
			dev_err(&spi->dev,
				"Failed read WILC_VMM_TO_HOST_SIZE ...\n");
			goto _fail_;
		}
		tmp = (byte_cnt >> 2) & IRQ_DMA_WD_CNT_MASK;
		*size = tmp;
	}

_fail_:
	return ret;
}

static int wilc_spi_read_int(struct wilc *wilc, u32 *int_status)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	int ret;
	u32 tmp;
	u32 byte_cnt;
	int happened, j;
	u32 unknown_mask;
	u32 irq_flags;

	if (g_spi.has_thrpt_enh) {
		ret = spi_internal_read(wilc, 0xe840 - WILC_SPI_REG_BASE,
					int_status);
	} else {
		ret = wilc_spi_read_reg(wilc, WILC_VMM_TO_HOST_SIZE,
					&byte_cnt);
		if (!ret) {
			dev_err(&spi->dev,
				"Failed read WILC_VMM_TO_HOST_SIZE ...\n");
			goto _fail_;
		}
		tmp = (byte_cnt >> 2) & IRQ_DMA_WD_CNT_MASK;

		j = 0;
		do {
			happened = 0;

			wilc_spi_read_reg(wilc, 0x1a90, &irq_flags);
			tmp |= ((irq_flags >> 27) << IRG_FLAGS_OFFSET);

			if (g_spi.nint > 5) {
				wilc_spi_read_reg(wilc, 0x1a94,
						  &irq_flags);
				tmp |= (((irq_flags >> 0) & 0x7) << (IRG_FLAGS_OFFSET + 5));
			}

			unknown_mask = ~((1ul << g_spi.nint) - 1);

			if ((tmp >> IRG_FLAGS_OFFSET) & unknown_mask) {
				dev_err(&spi->dev, "Unexpected interrupt (2): j=%d, tmp=%x, mask=%x\n", j, tmp, unknown_mask);
					happened = 1;
			}

			j++;
		} while (happened);

		*int_status = tmp;
	}

_fail_:
	return ret;
}

static int wilc_spi_clear_int_ext(struct wilc *wilc, u32 val)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	int ret;

	if (g_spi.has_thrpt_enh) {
		ret = spi_internal_write(wilc, 0xe844 - WILC_SPI_REG_BASE,
					 val);
	} else {
		u32 flags;

		flags = val & (BIT(MAX_NUM_INT) - 1);
		if (flags) {
			int i;

			ret = 1;
			for (i = 0; i < g_spi.nint; i++) {
				/* No matter what you write 1 or 0, it will clear interrupt. */
				if (flags & 1)
					ret = wilc_spi_write_reg(wilc, 0x10c8 + i * 4, 1);
				if (!ret)
					break;
				flags >>= 1;
			}
			if (!ret) {
				dev_err(&spi->dev,
					"Failed wilc_spi_write_reg, set reg %x ...\n",
					0x10c8 + i * 4);
				goto _fail_;
			}
			for (i = g_spi.nint; i < MAX_NUM_INT; i++) {
				if (flags & 1)
					dev_err(&spi->dev,
						"Unexpected interrupt cleared %d...\n",
						i);
				flags >>= 1;
			}
		}

		{
			u32 tbl_ctl;

			tbl_ctl = 0;
			/* select VMM table 0 */
			if ((val & SEL_VMM_TBL0) == SEL_VMM_TBL0)
				tbl_ctl |= BIT(0);
			/* select VMM table 1 */
			if ((val & SEL_VMM_TBL1) == SEL_VMM_TBL1)
				tbl_ctl |= BIT(1);

			ret = wilc_spi_write_reg(wilc, WILC_VMM_TBL_CTL,
						 tbl_ctl);
			if (!ret) {
				dev_err(&spi->dev,
					"fail write reg vmm_tbl_ctl...\n");
				goto _fail_;
			}

			if ((val & EN_VMM) == EN_VMM) {
				/**
				 *      enable vmm transfer.
				 **/
				ret = wilc_spi_write_reg(wilc,
							 WILC_VMM_CORE_CTL, 1);
				if (!ret) {
					dev_err(&spi->dev, "fail write reg vmm_core_ctl...\n");
					goto _fail_;
				}
			}
		}
	}
_fail_:
	return ret;
}

static int wilc_spi_sync_ext(struct wilc *wilc, int nint)
{
	struct spi_device *spi = to_spi_device(wilc->dev);
	u32 reg;
	int ret, i;

	if (nint > MAX_NUM_INT) {
		dev_err(&spi->dev, "Too many interrupts (%d)...\n", nint);
		return 0;
	}

	g_spi.nint = nint;

	/**
	 *      interrupt pin mux select
	 **/
	ret = wilc_spi_read_reg(wilc, WILC_PIN_MUX_0, &reg);
	if (!ret) {
		dev_err(&spi->dev, "Failed read reg (%08x)...\n",
			WILC_PIN_MUX_0);
		return 0;
	}
	reg |= BIT(8);
	ret = wilc_spi_write_reg(wilc, WILC_PIN_MUX_0, reg);
	if (!ret) {
		dev_err(&spi->dev, "Failed write reg (%08x)...\n",
			WILC_PIN_MUX_0);
		return 0;
	}

	/**
	 *      interrupt enable
	 **/
	ret = wilc_spi_read_reg(wilc, WILC_INTR_ENABLE, &reg);
	if (!ret) {
		dev_err(&spi->dev, "Failed read reg (%08x)...\n",
			WILC_INTR_ENABLE);
		return 0;
	}

	for (i = 0; (i < 5) && (nint > 0); i++, nint--)
		reg |= (BIT((27 + i)));

	ret = wilc_spi_write_reg(wilc, WILC_INTR_ENABLE, reg);
	if (!ret) {
		dev_err(&spi->dev, "Failed write reg (%08x)...\n",
			WILC_INTR_ENABLE);
		return 0;
	}
	if (nint) {
		ret = wilc_spi_read_reg(wilc, WILC_INTR2_ENABLE, &reg);
		if (!ret) {
			dev_err(&spi->dev, "Failed read reg (%08x)...\n",
				WILC_INTR2_ENABLE);
			return 0;
		}

		for (i = 0; (i < 3) && (nint > 0); i++, nint--)
			reg |= BIT(i);

		ret = wilc_spi_read_reg(wilc, WILC_INTR2_ENABLE, &reg);
		if (!ret) {
			dev_err(&spi->dev, "Failed write reg (%08x)...\n",
				WILC_INTR2_ENABLE);
			return 0;
		}
	}

	return 1;
}

/* Global spi HIF function table */
static const struct wilc_hif_func wilc_hif_spi = {
	.hif_init = wilc_spi_init,
	.hif_deinit = _wilc_spi_deinit,
	.hif_read_reg = wilc_spi_read_reg,
	.hif_write_reg = wilc_spi_write_reg,
	.hif_block_rx = wilc_spi_read,
	.hif_block_tx = wilc_spi_write,
	.hif_read_int = wilc_spi_read_int,
	.hif_clear_int_ext = wilc_spi_clear_int_ext,
	.hif_read_size = wilc_spi_read_size,
	.hif_block_tx_ext = wilc_spi_write,
	.hif_block_rx_ext = wilc_spi_read,
	.hif_sync_ext = wilc_spi_sync_ext,
};