system76-coreboot/src/drivers/spi/spi_flash.c

/*
 * 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 <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 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
#if defined(__GNUC__) && !defined(__clang__)
#pragma GCC diagnostic ignored "-Wstack-usage="
#endif
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);
}

/* Perform the read operation honoring spi controller fifo size, reissuing
 * the read command until the full request completed. */
static int spi_flash_cmd_read_array_wrapped(const struct spi_slave *spi,
				u8 *cmd, size_t cmd_len, u32 offset,
				size_t len, void *buf)
{
	int ret;
	size_t xfer_len;
	uint8_t *data = buf;

	while (len) {
		xfer_len = spi_crop_chunk(spi, cmd_len, len);

		/* Perform the read. */
		ret = spi_flash_cmd_read_array(spi, cmd, cmd_len,
						offset, xfer_len, data);

		if (ret)
			return ret;

		offset += xfer_len;
		data += xfer_len;
		len -= xfer_len;
	}

	return 0;
}

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_wrapped(&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_wrapped(&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;
	}
	if (len == 0) {
		printk(BIOS_WARNING, "SF: Erase length cannot be 0\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 IS_ENABLED(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;
	int (*probe) (const struct spi_slave *spi, u8 *idcode,
		      struct spi_flash *flash);
} flashes[] = {
	/* Keep it sorted by define name */
#if IS_ENABLED(CONFIG_SPI_FLASH_AMIC)
	{ 0, 0x37, spi_flash_probe_amic, },
#endif
#if IS_ENABLED(CONFIG_SPI_FLASH_ATMEL)
	{ 0, 0x1f, spi_flash_probe_atmel, },
#endif
#if IS_ENABLED(CONFIG_SPI_FLASH_EON)
	{ 0, 0x1c, spi_flash_probe_eon, },
#endif
#if IS_ENABLED(CONFIG_SPI_FLASH_GIGADEVICE)
	{ 0, 0xc8, spi_flash_probe_gigadevice, },
#endif
#if IS_ENABLED(CONFIG_SPI_FLASH_MACRONIX)
	{ 0, 0xc2, spi_flash_probe_macronix, },
#endif
#if IS_ENABLED(CONFIG_SPI_FLASH_SPANSION)
	{ 0, 0x01, spi_flash_probe_spansion, },
#endif
#if IS_ENABLED(CONFIG_SPI_FLASH_SST)
	{ 0, 0xbf, spi_flash_probe_sst, },
#endif
#if IS_ENABLED(CONFIG_SPI_FLASH_STMICRO)
	{ 0, 0x20, spi_flash_probe_stmicro, },
#endif
#if IS_ENABLED(CONFIG_SPI_FLASH_WINBOND)
	{ 0, 0xef, spi_flash_probe_winbond, },
#endif
	/* Keep it sorted by best detection */
#if IS_ENABLED(CONFIG_SPI_FLASH_STMICRO)
	{ 0, 0xff, spi_flash_probe_stmicro, },
#endif
#if IS_ENABLED(CONFIG_SPI_FLASH_ADESTO)
	{ 0, 0x1f, spi_flash_probe_adesto, },
#endif
};
#define IDCODE_LEN (IDCODE_CONT_LEN + IDCODE_PART_LEN)

int spi_flash_generic_probe(const struct spi_slave *spi,
				struct spi_flash *flash)
{
	int ret, i, shift;
	u8 idcode[IDCODE_LEN], *idp;

	/* Read the ID codes */
	ret = spi_flash_cmd(spi, CMD_READ_ID, idcode, sizeof(idcode));
	if (ret)
		return -1;

	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 */
			if (flashes[i].probe(spi, idp, flash) == 0) {
				flash->vendor = idp[0];
				flash->model = (idp[1] << 8) | idp[2];
				return 0;
			}
		}

	/* No match, return error. */
	return -1;
}

int spi_flash_probe(unsigned int bus, unsigned int cs, struct spi_flash *flash)
{
	struct spi_slave spi;
	int ret = -1;

	if (spi_setup_slave(bus, cs, &spi)) {
		printk(BIOS_WARNING, "SF: Failed to set up slave\n");
		return -1;
	}

	/* Try special programmer probe if any. */
	if (spi.ctrlr->flash_probe)
		ret = spi.ctrlr->flash_probe(&spi, flash);

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

	/* Give up -- nothing more to try if flash is not found. */
	if (ret) {
		printk(BIOS_WARNING, "SF: Unsupported manufacturer!\n");
		return -1;
	}

	printk(BIOS_INFO, "SF: Detected %s with sector size 0x%x, total 0x%x\n",
			flash->name, flash->sector_size, flash->size);
	if (bus == CONFIG_BOOT_DEVICE_SPI_FLASH_BUS
			&& flash->size != CONFIG_ROM_SIZE) {
		printk(BIOS_ERR, "SF size 0x%x does not correspond to"
			" CONFIG_ROM_SIZE 0x%x!!\n", flash->size,
			CONFIG_ROM_SIZE);
	}
	return 0;
}

int spi_flash_read(const struct spi_flash *flash, u32 offset, size_t len,
		void *buf)
{
	return flash->ops->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->ops->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->ops->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)
{
	if (flash->ops->status)
		return flash->ops->status(flash, reg);

	return -1;
}

int spi_flash_is_write_protected(const struct spi_flash *flash,
				 const struct region *region)
{
	struct region flash_region = { 0 };

	if (!flash || !region)
		return -1;

	flash_region.size = flash->size;

	if (!region_is_subregion(&flash_region, region))
		return -1;

	if (!flash->ops->get_write_protection) {
		printk(BIOS_WARNING, "SPI: Write-protection gathering not "
		       "implemented for this vendor.\n");
		return -1;
	}

	return flash->ops->get_write_protection(flash, region);
}

int spi_flash_set_write_protected(const struct spi_flash *flash,
				  const struct region *region,
				  const bool non_volatile,
				  const enum spi_flash_status_reg_lockdown mode)
{
	struct region flash_region = { 0 };
	int ret;

	if (!flash)
		return -1;

	flash_region.size = flash->size;

	if (!region_is_subregion(&flash_region, region))
		return -1;

	if (!flash->ops->set_write_protection) {
		printk(BIOS_WARNING, "SPI: Setting write-protection is not "
		       "implemented for this vendor.\n");
		return -1;
	}

	ret = flash->ops->set_write_protection(flash, region, non_volatile,
					       mode);

	if (ret == 0 && mode != SPI_WRITE_PROTECTION_PRESERVE) {
		printk(BIOS_INFO, "SPI: SREG lock-down was set to ");
		switch (mode) {
		case SPI_WRITE_PROTECTION_NONE:
			printk(BIOS_INFO, "NEVER\n");
		break;
		case SPI_WRITE_PROTECTION_PIN:
			printk(BIOS_INFO, "WP\n");
		break;
		case SPI_WRITE_PROTECTION_REBOOT:
			printk(BIOS_INFO, "REBOOT\n");
		break;
		case SPI_WRITE_PROTECTION_PERMANENT:
			printk(BIOS_INFO, "PERMANENT\n");
		break;
		default:
			printk(BIOS_INFO, "UNKNOWN\n");
		break;
		}
	}

	return ret;
}

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;
	const struct spi_flash *spi_flash_dev;

	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);

	spi_flash_dev = boot_device_spi_flash();

	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;
	}
}


int spi_flash_ctrlr_protect_region(const struct spi_flash *flash,
					const struct region *region)
{
	const struct spi_ctrlr *ctrlr;
	struct region flash_region = { 0 };

	if (!flash)
		return -1;

	flash_region.size = flash->size;

	if (!region_is_subregion(&flash_region, region))
		return -1;

	ctrlr = flash->spi.ctrlr;

	if (!ctrlr)
		return -1;

	if (ctrlr->flash_protect)
		return ctrlr->flash_protect(flash, region);

	return -1;
}

int spi_flash_vector_helper(const struct spi_slave *slave,
	struct spi_op vectors[], size_t count,
	int (*func)(const struct spi_slave *slave, const void *dout,
		    size_t bytesout, void *din, size_t bytesin))
{
	int ret;
	void *din;
	size_t bytes_in;

	if (count < 1 || count > 2)
		return -1;

	/* SPI flash commands always have a command first... */
	if (!vectors[0].dout || !vectors[0].bytesout)
		return -1;
	/* And not read any data during the command. */
	if (vectors[0].din || vectors[0].bytesin)
		return -1;

	if (count == 2) {
		/* If response bytes requested ensure the buffer is valid. */
		if (vectors[1].bytesin && !vectors[1].din)
			return -1;
		/* No sends can accompany a receive. */
		if (vectors[1].dout || vectors[1].bytesout)
			return -1;
		din = vectors[1].din;
		bytes_in = vectors[1].bytesin;
	} else {
		din = NULL;
		bytes_in = 0;
	}

	ret = func(slave, vectors[0].dout, vectors[0].bytesout, din, bytes_in);

	if (ret) {
		vectors[0].status = SPI_OP_FAILURE;
		if (count == 2)
			vectors[1].status = SPI_OP_FAILURE;
	} else {
		vectors[0].status = SPI_OP_SUCCESS;
		if (count == 2)
			vectors[1].status = SPI_OP_SUCCESS;
	}

	return ret;
}