/*
 * SPI flash interface
 *
 * Copyright (C) 2008 Atmel Corporation
 * Copyright (C) 2010 Reinhard Meyer, EMK Elektronik
 *
 * Licensed under the GPL-2 or later.
 */

#include <arch/early_variables.h>
#include <assert.h>
#include <boot_device.h>
#include <cbfs.h>
#include <cpu/x86/smm.h>
#include <delay.h>
#include <rules.h>
#include <stdlib.h>
#include <string.h>
#include <spi-generic.h>
#include <spi_flash.h>

#include "spi_flash_internal.h"
#include <timer.h>

static struct spi_flash *spi_flash_dev = NULL;

static void spi_flash_addr(u32 addr, u8 *cmd)
{
	/* cmd[0] is actual command */
	cmd[1] = addr >> 16;
	cmd[2] = addr >> 8;
	cmd[3] = addr >> 0;
}

static int do_spi_flash_cmd(const struct spi_slave *spi, const void *dout,
			    size_t bytes_out, void *din, size_t bytes_in)
{
	int ret = 1;
	/*
	 * SPI flash requires command-response kind of behavior. Thus, two
	 * separate SPI vectors are required -- first to transmit dout and other
	 * to receive in din. If some specialized SPI flash controllers
	 * (e.g. x86) can perform both command and response together, it should
	 * be handled at SPI flash controller driver level.
	 */
	struct spi_op vectors[] = {
		[0] = { .dout = dout, .bytesout = bytes_out,
			.din = NULL, .bytesin = 0, },
		[1] = { .dout = NULL, .bytesout = 0,
			.din = din, .bytesin = bytes_in },
	};
	size_t count = ARRAY_SIZE(vectors);
	if (!bytes_in)
		count = 1;

	if (spi_claim_bus(spi))
		return ret;

	if (spi_xfer_vector(spi, vectors, count) == 0)
		ret = 0;

	spi_release_bus(spi);
	return ret;
}

int spi_flash_cmd(const struct spi_slave *spi, u8 cmd, void *response, size_t len)
{
	int ret = do_spi_flash_cmd(spi, &cmd, sizeof(cmd), response, len);
	if (ret)
		printk(BIOS_WARNING, "SF: Failed to send command %02x: %d\n", cmd, ret);

	return ret;
}

static int spi_flash_cmd_read(const struct spi_slave *spi, const u8 *cmd,
			      size_t cmd_len, void *data, size_t data_len)
{
	int ret = do_spi_flash_cmd(spi, cmd, cmd_len, data, data_len);
	if (ret) {
		printk(BIOS_WARNING, "SF: Failed to send read command (%zu bytes): %d\n",
				data_len, ret);
	}

	return ret;
}

/* TODO: This code is quite possibly broken and overflowing stacks. Fix ASAP! */
#pragma GCC diagnostic push
#pragma GCC diagnostic ignored "-Wstack-usage="
int spi_flash_cmd_write(const struct spi_slave *spi, const u8 *cmd,
			size_t cmd_len, const void *data, size_t data_len)
{
	int ret;
	u8 buff[cmd_len + data_len];
	memcpy(buff, cmd, cmd_len);
	memcpy(buff + cmd_len, data, data_len);

	ret = do_spi_flash_cmd(spi, buff, cmd_len + data_len, NULL, 0);
	if (ret) {
		printk(BIOS_WARNING, "SF: Failed to send write command (%zu bytes): %d\n",
				data_len, ret);
	}

	return ret;
}
#pragma GCC diagnostic pop

static int spi_flash_cmd_read_array(const struct spi_slave *spi, u8 *cmd,
				    size_t cmd_len, u32 offset,
				    size_t len, void *data)
{
	spi_flash_addr(offset, cmd);
	return spi_flash_cmd_read(spi, cmd, cmd_len, data, len);
}

int spi_flash_cmd_read_fast(const struct spi_flash *flash, u32 offset,
			size_t len, void *data)
{
	u8 cmd[5];

	cmd[0] = CMD_READ_ARRAY_FAST;
	cmd[4] = 0x00;

	return spi_flash_cmd_read_array(&flash->spi, cmd, sizeof(cmd),
					offset, len, data);
}

int spi_flash_cmd_read_slow(const struct spi_flash *flash, u32 offset,
			size_t len, void *data)
{
	u8 cmd[4];

	cmd[0] = CMD_READ_ARRAY_SLOW;
	return spi_flash_cmd_read_array(&flash->spi, cmd, sizeof(cmd),
					offset, len, data);
}

int spi_flash_cmd_poll_bit(const struct spi_flash *flash, unsigned long timeout,
			   u8 cmd, u8 poll_bit)
{
	const struct spi_slave *spi = &flash->spi;
	int ret;
	u8 status;
	struct mono_time current, end;

	timer_monotonic_get(&current);
	end = current;
	mono_time_add_msecs(&end, timeout);

	do {
		ret = spi_flash_cmd_read(spi, &cmd, 1, &status, 1);
		if (ret)
			return -1;
		if ((status & poll_bit) == 0)
			return 0;
		timer_monotonic_get(&current);
	} while (!mono_time_after(&current, &end));

	printk(BIOS_DEBUG, "SF: timeout at %ld msec\n",timeout);
	return -1;
}

int spi_flash_cmd_wait_ready(const struct spi_flash *flash,
			unsigned long timeout)
{
	return spi_flash_cmd_poll_bit(flash, timeout,
		CMD_READ_STATUS, STATUS_WIP);
}

int spi_flash_cmd_erase(const struct spi_flash *flash, u32 offset, size_t len)
{
	u32 start, end, erase_size;
	int ret;
	u8 cmd[4];

	erase_size = flash->sector_size;
	if (offset % erase_size || len % erase_size) {
		printk(BIOS_WARNING, "SF: Erase offset/length not multiple of erase size\n");
		return -1;
	}

	cmd[0] = flash->erase_cmd;
	start = offset;
	end = start + len;

	while (offset < end) {
		spi_flash_addr(offset, cmd);
		offset += erase_size;

#if CONFIG_DEBUG_SPI_FLASH
		printk(BIOS_SPEW, "SF: erase %2x %2x %2x %2x (%x)\n", cmd[0], cmd[1],
		      cmd[2], cmd[3], offset);
#endif
		ret = spi_flash_cmd(&flash->spi, CMD_WRITE_ENABLE, NULL, 0);
		if (ret)
			goto out;

		ret = spi_flash_cmd_write(&flash->spi, cmd, sizeof(cmd), NULL, 0);
		if (ret)
			goto out;

		ret = spi_flash_cmd_wait_ready(flash, SPI_FLASH_PAGE_ERASE_TIMEOUT);
		if (ret)
			goto out;
	}

	printk(BIOS_DEBUG, "SF: Successfully erased %zu bytes @ %#x\n", len, start);

out:
	return ret;
}

int spi_flash_cmd_status(const struct spi_flash *flash, u8 *reg)
{
	return spi_flash_cmd(&flash->spi, flash->status_cmd, reg, sizeof(*reg));
}

/*
 * The following table holds all device probe functions
 *
 * shift:  number of continuation bytes before the ID
 * idcode: the expected IDCODE or 0xff for non JEDEC devices
 * probe:  the function to call
 *
 * Non JEDEC devices should be ordered in the table such that
 * the probe functions with best detection algorithms come first.
 *
 * Several matching entries are permitted, they will be tried
 * in sequence until a probe function returns non NULL.
 *
 * IDCODE_CONT_LEN may be redefined if a device needs to declare a
 * larger "shift" value.  IDCODE_PART_LEN generally shouldn't be
 * changed.  This is the max number of bytes probe functions may
 * examine when looking up part-specific identification info.
 *
 * Probe functions will be given the idcode buffer starting at their
 * manu id byte (the "idcode" in the table below).  In other words,
 * all of the continuation bytes will be skipped (the "shift" below).
 */
#define IDCODE_CONT_LEN 0
#define IDCODE_PART_LEN 5
static struct {
	const u8 shift;
	const u8 idcode;
	struct spi_flash *(*probe) (struct spi_slave *spi, u8 *idcode);
} flashes[] = {
	/* Keep it sorted by define name */
#if CONFIG_SPI_FLASH_AMIC
	{ 0, 0x37, spi_flash_probe_amic, },
#endif
#if CONFIG_SPI_FLASH_ATMEL
	{ 0, 0x1f, spi_flash_probe_atmel, },
#endif
#if CONFIG_SPI_FLASH_EON
	{ 0, 0x1c, spi_flash_probe_eon, },
#endif
#if CONFIG_SPI_FLASH_GIGADEVICE
	{ 0, 0xc8, spi_flash_probe_gigadevice, },
#endif
#if CONFIG_SPI_FLASH_MACRONIX
	{ 0, 0xc2, spi_flash_probe_macronix, },
#endif
#if CONFIG_SPI_FLASH_SPANSION
	{ 0, 0x01, spi_flash_probe_spansion, },
#endif
#if CONFIG_SPI_FLASH_SST
	{ 0, 0xbf, spi_flash_probe_sst, },
#endif
#if CONFIG_SPI_FLASH_STMICRO
	{ 0, 0x20, spi_flash_probe_stmicro, },
#endif
#if CONFIG_SPI_FLASH_WINBOND
	{ 0, 0xef, spi_flash_probe_winbond, },
#endif
	/* Keep it sorted by best detection */
#if CONFIG_SPI_FLASH_STMICRO
	{ 0, 0xff, spi_flash_probe_stmicro, },
#endif
#if CONFIG_SPI_FLASH_ADESTO
	{ 0, 0x1f, spi_flash_probe_adesto, },
#endif
};
#define IDCODE_LEN (IDCODE_CONT_LEN + IDCODE_PART_LEN)

struct spi_flash *
__attribute__((weak)) spi_flash_programmer_probe(struct spi_slave *spi,
						 int force)
{
	/* Default weak implementation. Do nothing. */
	return NULL;
}

static struct spi_flash *__spi_flash_probe(struct spi_slave *spi)
{
	int ret, i, shift;
	u8 idcode[IDCODE_LEN], *idp;
	struct spi_flash *flash = NULL;

	/* Read the ID codes */
	ret = spi_flash_cmd(spi, CMD_READ_ID, idcode, sizeof(idcode));
	if (ret)
		return NULL;

	if (IS_ENABLED(CONFIG_DEBUG_SPI_FLASH)) {
		printk(BIOS_SPEW, "SF: Got idcode: ");
		for (i = 0; i < sizeof(idcode); i++)
			printk(BIOS_SPEW, "%02x ", idcode[i]);
		printk(BIOS_SPEW, "\n");
	}

	/* count the number of continuation bytes */
	for (shift = 0, idp = idcode; shift < IDCODE_CONT_LEN && *idp == 0x7f;
	     ++shift, ++idp)
		continue;

	printk(BIOS_INFO, "Manufacturer: %02x\n", *idp);

	/* search the table for matches in shift and id */
	for (i = 0; i < ARRAY_SIZE(flashes); ++i)
		if (flashes[i].shift == shift && flashes[i].idcode == *idp) {
			/* we have a match, call probe */
			flash = flashes[i].probe(spi, idp);
			if (flash)
				break;
		}

	return flash;
}

struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs)
{
	struct spi_slave spi;
	struct spi_flash *flash;

	if (spi_setup_slave(bus, cs, &spi)) {
		printk(BIOS_WARNING, "SF: Failed to set up slave\n");
		return NULL;
	}

	/* Try special programmer probe if any (without force). */
	flash = spi_flash_programmer_probe(&spi, 0);

	/* If flash is not found, try generic spi flash probe. */
	if (!flash)
		flash = __spi_flash_probe(&spi);

	/* If flash is not yet found, force special programmer probe if any. */
	if (!flash)
		flash = spi_flash_programmer_probe(&spi, 1);

	/* Give up -- nothing more to try if flash is not found. */
	if (!flash) {
		printk(BIOS_WARNING, "SF: Unsupported manufacturer!\n");
		return NULL;
	}

	printk(BIOS_INFO, "SF: Detected %s with sector size 0x%x, total 0x%x\n",
			flash->name, flash->sector_size, flash->size);

	/*
	 * Only set the global spi_flash_dev if this is the boot
	 * device's bus and it's previously unset while in ramstage.
	 */
	if (ENV_RAMSTAGE && IS_ENABLED(CONFIG_BOOT_DEVICE_SPI_FLASH) &&
		CONFIG_BOOT_DEVICE_SPI_FLASH_BUS == bus && !spi_flash_dev)
		spi_flash_dev = flash;

	return flash;
}

int spi_flash_read(const struct spi_flash *flash, u32 offset, size_t len,
		void *buf)
{
	return flash->internal_read(flash, offset, len, buf);
}

int spi_flash_write(const struct spi_flash *flash, u32 offset, size_t len,
		const void *buf)
{
	int ret;

	if (spi_flash_volatile_group_begin(flash))
		return -1;

	ret = flash->internal_write(flash, offset, len, buf);

	if (spi_flash_volatile_group_end(flash))
		return -1;

	return ret;
}

int spi_flash_erase(const struct spi_flash *flash, u32 offset, size_t len)
{
	int ret;

	if (spi_flash_volatile_group_begin(flash))
		return -1;

	ret = flash->internal_erase(flash, offset, len);

	if (spi_flash_volatile_group_end(flash))
		return -1;

	return ret;
}

int spi_flash_status(const struct spi_flash *flash, u8 *reg)
{
	return flash->internal_status(flash, reg);
}

static uint32_t volatile_group_count CAR_GLOBAL;

int spi_flash_volatile_group_begin(const struct spi_flash *flash)
{
	uint32_t count;
	int ret = 0;

	if (!IS_ENABLED(CONFIG_SPI_FLASH_HAS_VOLATILE_GROUP))
		return ret;

	count = car_get_var(volatile_group_count);
	if (count == 0)
		ret = chipset_volatile_group_begin(flash);

	count++;
	car_set_var(volatile_group_count, count);
	return ret;
}

int spi_flash_volatile_group_end(const struct spi_flash *flash)
{
	uint32_t count;
	int ret = 0;

	if (!IS_ENABLED(CONFIG_SPI_FLASH_HAS_VOLATILE_GROUP))
		return ret;

	count = car_get_var(volatile_group_count);
	assert(count == 0);
	count--;
	car_set_var(volatile_group_count, count);

	if (count == 0)
		ret = chipset_volatile_group_end(flash);

	return ret;
}

void lb_spi_flash(struct lb_header *header)
{
	struct lb_spi_flash *flash;

	if (!IS_ENABLED(CONFIG_BOOT_DEVICE_SPI_FLASH))
		return;

	flash = (struct lb_spi_flash *)lb_new_record(header);

	flash->tag = LB_TAG_SPI_FLASH;
	flash->size = sizeof(*flash);

	/* Try to get the flash device if not loaded yet */
	if (!spi_flash_dev)
		boot_device_init();

	if (spi_flash_dev) {
		flash->flash_size = spi_flash_dev->size;
		flash->sector_size = spi_flash_dev->sector_size;
		flash->erase_cmd = spi_flash_dev->erase_cmd;
	} else {
		flash->flash_size = CONFIG_ROM_SIZE;
		/* Default 64k erase command should work on most flash.
		 * Uniform 4k erase only works on certain devices. */
		flash->sector_size = 64 * KiB;
		flash->erase_cmd = CMD_BLOCK_ERASE;
	}
}