Add VIA VT6421A LPC programmer driver

Due to the mysterious address handling of this chip the user can specify
a base address with the offset parameter, e.g.:
flashrom -p atavia:offset=0xFFF00000

Thanks to Idwer Vollering for his iterative testing of this code, as well as to
Martijn Bastiaan who did the last tests before merging.

Corresponding to flashrom svn r1809.

Signed-off-by: Jonathan Kollasch <jakllsch@kollasch.net>
Signed-off-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
diff --git a/atavia.c b/atavia.c
new file mode 100644
index 0000000..952a860
--- /dev/null
+++ b/atavia.c
@@ -0,0 +1,197 @@
+/*
+ * This file is part of the flashrom project.
+ *
+ * Copyright (C) 2010 Uwe Hermann <uwe@hermann-uwe.de>
+ * Copyright (C) 2011 Jonathan Kollasch <jakllsch@kollasch.net>
+ * Copyright (C) 2012-2013 Stefan Tauner
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include "flash.h"
+#include "programmer.h"
+#include "hwaccess.h"
+
+#define PCI_VENDOR_ID_VIA	0x1106
+
+#define VIA_MAX_RETRIES		300
+
+#define BROM_ADDR		0x60
+
+#define BROM_DATA		0x64
+
+#define BROM_ACCESS		0x68
+#define BROM_TRIGGER		0x80
+#define BROM_WRITE		0x40
+#define BROM_SIZE_MASK		0x30
+#define BROM_SIZE_64K		0x00
+#define BROM_SIZE_32K		0x10
+#define BROM_SIZE_16K		0x20
+#define BROM_SIZE_0K		0x30
+#define BROM_BYTE_ENABLE_MASK	0x0f
+
+#define BROM_STATUS		0x69
+#define BROM_ERROR_STATUS	0x80
+
+/* Select the byte we want to access. This is done by clearing the bit corresponding to the byte we want to
+ * access, leaving the others set (yes, really). */
+#define ENABLE_BYTE(address)	((~(1 << ((address) & 3))) & BROM_BYTE_ENABLE_MASK)
+#define BYTE_OFFSET(address)	(((addr) & 3) * 8)
+
+const struct dev_entry ata_via[] = {
+	{PCI_VENDOR_ID_VIA, 0x3249, DEP, "VIA", "VT6421A"},
+
+	{},
+};
+
+static void atavia_chip_writeb(const struct flashctx *flash, uint8_t val, chipaddr addr);
+static uint8_t atavia_chip_readb(const struct flashctx *flash, const chipaddr addr);
+static const struct par_programmer lpc_programmer_atavia = {
+		.chip_readb		= atavia_chip_readb,
+		.chip_readw		= fallback_chip_readw,
+		.chip_readl		= fallback_chip_readl,
+		.chip_readn		= fallback_chip_readn,
+		.chip_writeb		= atavia_chip_writeb,
+		.chip_writew		= fallback_chip_writew,
+		.chip_writel		= fallback_chip_writel,
+		.chip_writen		= fallback_chip_writen,
+};
+
+static void *atavia_offset = NULL;
+struct pci_dev *dev = NULL;
+
+static void atavia_prettyprint_access(uint8_t access)
+{
+	uint8_t bmask = access & BROM_BYTE_ENABLE_MASK;
+	uint8_t size = access & BROM_SIZE_MASK;
+
+	msg_pspew("Accessing byte(s):%s%s%s%s\n",
+		  ((bmask & (1<<3)) == 0) ? " 3" : "",
+		  ((bmask & (1<<2)) == 0) ? " 2" : "",
+		  ((bmask & (1<<1)) == 0) ? " 1" : "",
+		  ((bmask & (1<<0)) == 0) ? " 0" : "");
+	if (size == BROM_SIZE_0K) {
+		msg_pspew("No ROM device found.\n");
+	} else
+		msg_pspew("ROM device with %s kB attached.\n",
+			  (size == BROM_SIZE_64K) ? ">=64" :
+			  (size == BROM_SIZE_32K) ? "32" : "16");
+	msg_pspew("Access is a %s.\n", (access & BROM_WRITE) ? "write" : "read");
+	msg_pspew("Device is %s.\n", (access & BROM_TRIGGER) ? "busy" : "ready");
+}
+
+static bool atavia_ready(struct pci_dev *pcidev_dev)
+{
+	int try;
+	uint8_t access, status;
+	bool ready = false;
+
+	for (try = 0; try < VIA_MAX_RETRIES; try++) {
+		access = pci_read_byte(pcidev_dev, BROM_ACCESS);
+		status = pci_read_byte(pcidev_dev, BROM_STATUS);
+		if (((access & BROM_TRIGGER) == 0) && (status & BROM_ERROR_STATUS) == 0) {
+			ready = true;
+			break;
+		} else {
+			programmer_delay(1);
+			continue;
+		}
+	}
+
+	msg_pdbg2("\n%s: %s after %d tries (access=0x%02x, status=0x%02x)\n",
+		  __func__, ready ? "suceeded" : "failed", try, access, status);
+	atavia_prettyprint_access(access);
+	return ready;
+}
+
+void *atavia_map(const char *descr, unsigned long phys_addr, size_t len)
+{
+	return (atavia_offset != 0) ? atavia_offset : (void *)phys_addr;
+}
+
+int atavia_init(void)
+{
+	char *arg = extract_programmer_param("offset");
+	if (arg) {
+		if (strlen(arg) == 0) {
+			msg_perr("Missing argument for offset.\n");
+			free(arg);
+			return ERROR_FATAL;
+		}
+		char *endptr;
+		atavia_offset = (void *)strtoul(arg, &endptr, 0);
+		if (*endptr) {
+			msg_perr("Error: Invalid offset specified: \"%s\".\n", arg);
+			free(arg);
+			return ERROR_FATAL;
+		}
+		msg_pinfo("Mapping addresses to base %p.\n", atavia_offset);
+	}
+	free(arg);
+
+	if (rget_io_perms())
+		return 1;
+
+	/* No need to check for errors, pcidev_init() will not return in case of errors. */
+	dev = pcidev_init(ata_via, PCI_ROM_ADDRESS); /* Acutally no BAR setup needed at all. */
+	if (!dev)
+		return 1;
+
+	/* Test if a flash chip is attached. */
+	pci_write_long(dev, PCI_ROM_ADDRESS, (uint32_t)PCI_ROM_ADDRESS_MASK);
+	programmer_delay(90);
+	uint32_t base = pci_read_long(dev, PCI_ROM_ADDRESS);
+	msg_pdbg2("BROM base=0x%08x\n", base);
+	if ((base & PCI_ROM_ADDRESS_MASK) == 0) {
+		msg_pwarn("Controller thinks there is no ROM attached.\n");
+	}
+
+	if (!atavia_ready(dev)) {
+		msg_perr("Controller not ready.\n");
+		return 1;
+	}
+
+	register_par_programmer(&lpc_programmer_atavia, BUS_LPC);
+
+	return 0;
+}
+
+static void atavia_chip_writeb(const struct flashctx *flash, uint8_t val, const chipaddr addr)
+{
+	msg_pspew("%s: 0x%02x to 0x%08lx.\n", __func__, val, addr);
+	pci_write_long(dev, BROM_ADDR, (addr & ~3));
+	pci_write_long(dev, BROM_DATA, val << BYTE_OFFSET(addr));
+	pci_write_byte(dev, BROM_ACCESS, BROM_TRIGGER | BROM_WRITE | ENABLE_BYTE(addr));
+
+	if (!atavia_ready(dev)) {
+		msg_perr("not ready after write\n");
+	}
+}
+
+static uint8_t atavia_chip_readb(const struct flashctx *flash, const chipaddr addr)
+{
+	pci_write_long(dev, BROM_ADDR, (addr & ~3));
+	pci_write_byte(dev, BROM_ACCESS, BROM_TRIGGER | ENABLE_BYTE(addr));
+
+	if (!atavia_ready(dev)) {
+		msg_perr("not ready after read\n");
+	}
+
+	uint8_t val = (pci_read_long(dev, BROM_DATA) >> BYTE_OFFSET(addr)) & 0xff;
+	msg_pspew("%s: 0x%02x from 0x%08lx.\n", __func__, val, addr);
+	return val;
+}