gec.c

// Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "flashchips.h"
#include "gec_lpc_commands.h"
#include "programmer.h"
#include "spi.h"
#include "writeprotect.h"


static int ec_timeout_usec = 1000000;

/* Waits for the EC to be unbusy. Returns 1 if busy, 0 if not busy. */
static int ec_busy(int timeout_usec)
{
	int i;
	for (i = 0; i < timeout_usec; i += 10) {
		usleep(10);  /* Delay first, in case we just sent a command */
		if (!(inb(EC_LPC_ADDR_USER_CMD) & EC_LPC_STATUS_BUSY_MASK))
			return 0;
	}
	return 1;  /* Timeout */
}


static enum lpc_status gec_get_result() {
	return inb(EC_LPC_ADDR_USER_DATA);
}


/* Sends a command to the EC.  Returns the command status code, or
 * -1 if other error. */
int ec_command(int command, const void *indata, int insize,
	       void *outdata, int outsize) {
	uint8_t *d;
	int i;

	if ((insize + outsize) > EC_LPC_PARAM_SIZE) {
		msg_pdbg2("Data size too big for buffer.\n");
		return -1;
	}

	if (ec_busy(ec_timeout_usec)) {
		msg_pdbg2("Timeout waiting for EC ready\n");
		return -1;
	}

	/* Write data, if any */
	/* TODO: optimized copy using outl() */
	for (i = 0, d = (uint8_t *)indata; i < insize; i++, d++) {
		msg_pdbg2("GEC: Port[0x%x] <-- 0x%x\n",
		          EC_LPC_ADDR_USER_PARAM + i, *d);
		outb(*d, EC_LPC_ADDR_USER_PARAM + i);
	}

	msg_pdbg2("GEC: Run EC Command: 0x%x ----\n", command);
	outb(command, EC_LPC_ADDR_USER_CMD);

	if (ec_busy(1000000)) {
		msg_pdbg2("Timeout waiting for EC response\n");
		return -1;
	}

	/* Check status */
	if ((i = gec_get_result()) != EC_LPC_RESULT_SUCCESS) {
		msg_pdbg2("EC returned error status %d\n", i);
		return i;
	}

	/* Read data, if any */
	for (i = 0, d = (uint8_t *)outdata; i < outsize; i++, d++) {
		*d = inb(EC_LPC_ADDR_USER_PARAM + i);
		msg_pdbg2("GEC: Port[0x%x] ---> 0x%x\n",
		          EC_LPC_ADDR_USER_PARAM + i, *d);
	}

	return 0;
}


#ifdef SUPPORT_CHECKSUM
static verify_checksum(uint8_t* expected,
                       unsigned int addr,
                       unsigned int count) {
	int rc;
	struct lpc_params_flash_checksum csp;
	struct lpc_response_flash_checksum csr;
	uint8_t cs;
	int j;

	csp.offset = addr;
	csp.size = count;

	rc = ec_command(EC_LPC_COMMAND_FLASH_CHECKSUM,
			&csp, sizeof(csp), &csr, sizeof(csr));
	if (rc) {
		msg_perr("GEC: verify_checksum() error.\n");
		return rc;
	}

	for (cs = 0, j = 0; j < count; ++j) {
		BYTE_IN(cs, expected[j]);
	}
	if (cs != csr.checksum) {
		msg_pdbg("GEC: checksum dismatch at 0x%02x "
		         "(ec: 0x%02x, local: 0x%02x). Retry.\n",
		         addr, csr.checksum, cs);
		msg_pdbg("GEC: ");
		for (j = 0; j < count; ++j) {
			msg_pdbg("%02x-", expected[j]);
			if ((j & 15) == 15) msg_pdbg("\nGEC: ");
		}
		programmer_delay(1000);
		return 1;
	}
	return 0;
}
#endif  /* SUPPORT_CHECKSUM */


int gec_read(struct flashchip *flash, uint8_t *readarr,
             unsigned int blockaddr, unsigned int readcnt) {
	int i;
	int rc = 0;
	struct lpc_params_flash_read p;
	struct lpc_response_flash_read r;

	for (i = 0; i < readcnt; i += EC_LPC_FLASH_SIZE_MAX) {
		p.offset = blockaddr + i;
		p.size = min(readcnt - i, EC_LPC_FLASH_SIZE_MAX);
		rc = ec_command(EC_LPC_COMMAND_FLASH_READ,
		                &p, sizeof(p), &r, sizeof(r));
		if (rc) {
			msg_perr("GEC: Flash read error at offset 0x%x\n",
			         blockaddr + i);
			return rc;
		}

#ifdef SUPPORT_CHECKSUM
		if (verify_checksum(r.data, blockaddr + i,
			            min(readcnt - i, EC_LPC_FLASH_SIZE_MAX))) {
			msg_pdbg("GEC: re-read...\n");
			i -= EC_LPC_FLASH_SIZE_MAX;
			continue;
		}
#endif
		memcpy(readarr + i, r.data, p.size);
	}

	return rc;
}


static int gec_block_erase(struct flashchip *flash,
                           unsigned int blockaddr,
                           unsigned int len) {
	struct lpc_params_flash_erase erase;
	int rc;
	uint8_t *blank;

#ifdef SUPPORT_CHECKSUM
re_erase:
#endif
	erase.offset = blockaddr;
	erase.size = len;
	rc = ec_command(EC_LPC_COMMAND_FLASH_ERASE, &erase, sizeof(erase),
	                NULL, 0);
	if (rc) {
		msg_perr("GEC: Flash erase error at address 0x%x\n", blockaddr);
		return rc;
	}

#ifdef SUPPORT_CHECKSUM
	blank = malloc(len);
	memset(blank, 0xff, len);
	if (verify_checksum(blank, blockaddr, len)) {
		msg_pdbg("GEC: Re-erase...\n");
		goto re_erase;
	}
#endif

	return rc;
}


int gec_write(struct flashchip *flash, uint8_t *buf, unsigned int addr,
                    unsigned int nbytes) {
	int i, rc = 0;
	unsigned int written = 0;
	struct lpc_params_flash_write p;

	for (i = 0; i < nbytes; i += written) {
		written = min(nbytes - i, EC_LPC_FLASH_SIZE_MAX);
		p.offset = addr + i;
		p.size = written;
		memcpy(p.data, &buf[i], written);
		rc = ec_command(EC_LPC_COMMAND_FLASH_WRITE, &p, sizeof(p),
		                NULL, 0);

#ifdef SUPPORT_CHECKSUM
		if (verify_checksum(&buf[i], addr + i, written)) {
			msg_pdbg("GEC: re-write...\n");
			i -= written;
			continue;
		}
#endif

		if (rc) break;
	}

	return rc;
}


static int gec_list_ranges(const struct flashchip *flash) {
	msg_pinfo("You can specify any range:\n");
	msg_pinfo("  from: 0x%06x, to: 0x%06x\n", 0, flash->total_size * 1024);
	msg_pinfo("  unit: 0x%06x (%dKB)\n", 2048, 2048);
	return 0;
}


static int gec_set_range(const struct flashchip *flash,
                         unsigned int start, unsigned int len) {
	struct lpc_params_flash_wp_range p;
	int rc;

	p.offset = start;
	p.size = len;
	rc = ec_command(EC_LPC_COMMAND_FLASH_WP_SET_RANGE, &p, sizeof(p),
	                NULL, 0);
	if (rc) {
		msg_perr("GEC: wp_set_range error: rc=%d\n", rc);
		return rc;
	}

	return 0;
}


static int gec_enable_writeprotect(const struct flashchip *flash) {
	struct lpc_params_flash_wp_enable p;
	int rc;

	p.enable_wp = 1;
	rc = ec_command(EC_LPC_COMMAND_FLASH_WP_ENABLE, &p, sizeof(p),
	                NULL, 0);
	if (rc) {
		msg_perr("GEC: wp_enable_wp error: rc=%d\n", rc);
	}

	return rc;
}


static int gec_disable_writeprotect(const struct flashchip *flash) {
	struct lpc_params_flash_wp_enable p;
	int rc;

	p.enable_wp = 0;
	rc = ec_command(EC_LPC_COMMAND_FLASH_WP_ENABLE, &p, sizeof(p),
	                NULL, 0);
	if (rc) {
		msg_perr("GEC: wp_disable_wp error: rc=%d\n", rc);
	} else {
		msg_pinfo("Disabled WP. Reboot EC and de-assert #WP.\n");
	}

	return rc;
}


static int gec_wp_status(const struct flashchip *flash) {
	int rc;
	struct lpc_response_flash_wp_range range;
	struct lpc_response_flash_wp_enable en;
	uint8_t value;

	rc = ec_command(EC_LPC_COMMAND_FLASH_WP_GET_RANGE, NULL, 0,
	                &range, sizeof(range));
	if (rc) {
		msg_perr("GEC: wp_get_wp_range error: rc=%d\n", rc);
		return rc;
	}
	rc = ec_command(EC_LPC_COMMAND_FLASH_WP_GET_STATE, NULL, 0,
	                &en, sizeof(en));
	if (rc) {
		msg_perr("GEC: wp_get_wp_state error: rc=%d\n", rc);
		return rc;
	}

	/* TODO: Fix scripts which rely on SPI-specific terminology. */
	value = (en.enable_wp << 7);
	msg_pinfo("WP: status: 0x%02x\n", value);
	msg_pinfo("WP: status.srp0: %x\n", en.enable_wp);
	msg_pinfo("WP: write protect is %s.\n",
	          en.enable_wp ? "enabled" : "disabled");
	msg_pinfo("WP: write protect range: start=0x%08x, len=0x%08x\n",
	          range.offset, range.size);

	return 0;
}


static int gec_probe_size(struct flashchip *flash) {
	int rc;
	struct lpc_response_flash_info info;
	struct block_eraser *eraser;
	static struct wp wp = {
		.list_ranges    = gec_list_ranges,
		.set_range      = gec_set_range,
		.enable         = gec_enable_writeprotect,
		.disable        = gec_disable_writeprotect,
		.wp_status      = gec_wp_status,
	};

	rc = ec_command(EC_LPC_COMMAND_FLASH_INFO, NULL, 0,
	                &info, sizeof(info));
	if (rc) return 0;

	flash->total_size = info.flash_size / 1024;
	flash->page_size = min(info.write_block_size,
	                       info.erase_block_size);
	flash->tested = TEST_OK_PREW;
	eraser = &flash->block_erasers[0];
	eraser->eraseblocks[0].size = info.erase_block_size;
	eraser->eraseblocks[0].count = info.flash_size /
	                               eraser->eraseblocks[0].size;
	flash->wp = &wp;

	return 1;
};


static const struct opaque_programmer opaque_programmer_gec = {
	.max_data_read = EC_LPC_FLASH_SIZE_MAX,
	.max_data_write = EC_LPC_FLASH_SIZE_MAX,
	.probe = gec_probe_size,
	.read = gec_read,
	.write = gec_write,
	.erase = gec_block_erase,
};


/* Sends HELLO command to ACPI port and expects a value from Google EC.
 *
 * TODO: This is an intrusive command for non-Google ECs. Needs a more proper
 *       and more friendly way to detect.
 */
static int detect_ec(void) {
	struct lpc_params_hello request;
	struct lpc_response_hello response;
	int rc = 0;
	int old_timeout = ec_timeout_usec;

	if (target_bus != BUS_LPC) {
		msg_pdbg("%s():%d target_bus is not LPC.\n", __func__, __LINE__);
		return 1;
	}

	/* reduce timeout period temporarily in case EC is not present */
	ec_timeout_usec = 25000;

	/* Say hello to EC. */
	request.in_data = 0xf0e0d0c0;  /* Expect EC will add on 0x01020304. */
	rc = ec_command(EC_LPC_COMMAND_HELLO, &request, sizeof(request),
	                &response, sizeof(response));

	ec_timeout_usec = old_timeout;

	if (rc || response.out_data != 0xf1e2d3c4) {
		msg_pdbg("response.out_data is not 0xf1e2d3c4.\n"
		         "rc=%d, request=0x%x response=0x%x\n",
		         rc, request.in_data, response.out_data);
#ifdef SUPPORT_CHECKSUM
		/* In this mode, we can tolerate some bit errors. */
		{
			int diff = response.out_data ^ 0xf1e2d3c4;
			if (!(diff = (diff - 1) & diff)) return 0;// 1-bit error
			if (!(diff = (diff - 1) & diff)) return 0;// 2-bit error
			if (!(diff = (diff - 1) & diff)) return 0;// 3-bit error
			if (!(diff = (diff - 1) & diff)) return 0;// 4-bit error
		}
#endif
		return 1;
	}

	return 0;
}

/* Called by internal_init() */
int gec_probe_programmer(const char *name) {
	struct pci_dev *dev;

	msg_pdbg("%s():%d ...\n", __func__, __LINE__);

	if (detect_ec()) return 1;

	register_opaque_programmer(&opaque_programmer_gec);
	if (buses_supported & BUS_SPI) {
		msg_pdbg("%s():%d remove BUS_SPI from buses_supported.\n",
		         __func__, __LINE__);
		buses_supported &= ~BUS_SPI;
	}
	buses_supported |= BUS_LPC;

	return 0;
}