1 files changed, 109 insertions, 0 deletions
diff --git a/drivers/mtd/maps/tsunami_flash.c b/drivers/mtd/maps/tsunami_flash.c
new file mode 100644
index 000000000..9fc1f727a
--- /dev/null
+++ b/drivers/mtd/maps/tsunami_flash.c
@@ -0,0 +1,109 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * tsunami_flash.c
+ *
+ * flash chip on alpha ds10...
+ */
+#include <asm/io.h>
+#include <asm/core_tsunami.h>
+#include <linux/init.h>
+#include <linux/mtd/map.h>
+#include <linux/mtd/mtd.h>
+
+#define FLASH_ENABLE_PORT 0x00C00001
+#define FLASH_ENABLE_BYTE 0x01
+#define FLASH_DISABLE_BYTE 0x00
+
+#define MAX_TIG_FLASH_SIZE (12*1024*1024)
+static inline map_word tsunami_flash_read8(struct map_info *map, unsigned long offset)
+{
+	map_word val;
+	val.x[0] = tsunami_tig_readb(offset);
+	return val;
+}
+
+static void tsunami_flash_write8(struct map_info *map, map_word value, unsigned long offset)
+{
+	tsunami_tig_writeb(value.x[0], offset);
+}
+
+static void tsunami_flash_copy_from(
+	struct map_info *map, void *addr, unsigned long offset, ssize_t len)
+{
+	unsigned char *dest;
+	dest = addr;
+	while(len && (offset < MAX_TIG_FLASH_SIZE)) {
+		*dest = tsunami_tig_readb(offset);
+		offset++;
+		dest++;
+		len--;
+	}
+}
+
+static void tsunami_flash_copy_to(
+	struct map_info *map, unsigned long offset,
+	const void *addr, ssize_t len)
+{
+	const unsigned char *src;
+	src = addr;
+	while(len && (offset < MAX_TIG_FLASH_SIZE)) {
+		tsunami_tig_writeb(*src, offset);
+		offset++;
+		src++;
+		len--;
+	}
+}
+
+/*
+ * Deliberately don't provide operations wider than 8 bits.  I don't
+ * have then and it scares me to think how you could mess up if
+ * you tried to use them.   Buswidth is correctly so I'm safe.
+ */
+static struct map_info tsunami_flash_map = {
+	.name = "flash chip on the Tsunami TIG bus",
+	.size = MAX_TIG_FLASH_SIZE,
+	.phys = NO_XIP,
+	.bankwidth = 1,
+	.read = tsunami_flash_read8,
+	.copy_from = tsunami_flash_copy_from,
+	.write = tsunami_flash_write8,
+	.copy_to = tsunami_flash_copy_to,
+};
+
+static struct mtd_info *tsunami_flash_mtd;
+
+static void __exit  cleanup_tsunami_flash(void)
+{
+	struct mtd_info *mtd;
+	mtd = tsunami_flash_mtd;
+	if (mtd) {
+		mtd_device_unregister(mtd);
+		map_destroy(mtd);
+	}
+	tsunami_flash_mtd = 0;
+}
+
+static const char * const rom_probe_types[] = {
+	"cfi_probe", "jedec_probe", "map_rom", NULL };
+
+static int __init init_tsunami_flash(void)
+{
+	const char * const *type;
+
+	tsunami_tig_writeb(FLASH_ENABLE_BYTE, FLASH_ENABLE_PORT);
+
+	tsunami_flash_mtd = 0;
+	type = rom_probe_types;
+	for(; !tsunami_flash_mtd && *type; type++) {
+		tsunami_flash_mtd = do_map_probe(*type, &tsunami_flash_map);
+	}
+	if (tsunami_flash_mtd) {
+		tsunami_flash_mtd->owner = THIS_MODULE;
+		mtd_device_register(tsunami_flash_mtd, NULL, 0);
+		return 0;
+	}
+	return -ENXIO;
+}
+
+module_init(init_tsunami_flash);
+module_exit(cleanup_tsunami_flash);