spi: Add SPI flash test

It is useful to have a basic SPI flash test, which tests that the SPI chip,
the SPI bus and the driver are behaving.

This test erases part of the flash, writes data and reads it back as a
sanity check that all is well.

Use CONFIG_SF_TEST to enable it.

Signed-off-by: Simon Glass <sjg@chromium.org>

README

@@ -2390,6 +2390,11 @@ CBFS (Coreboot Filesystem) support
 		CONFIG_SF_DEFAULT_MODE 		(see include/spi.h)
 		CONFIG_SF_DEFAULT_SPEED		in Hz
 
+		CONFIG_CMD_SF_TEST
+
+		Define this option to include a destructive SPI flash
+		test ('sf test').
+
 - SystemACE Support:
 		CONFIG_SYSTEMACE
 

common/cmd_sf.c

@@ -5,6 +5,7 @@
  * Licensed under the GPL-2 or later.
  */
 
+#include <div64.h>
 #include <common.h>
 #include <malloc.h>
 #include <spi_flash.h>
@@ -312,6 +313,161 @@ static int do_spi_flash_erase(int argc, char * const argv[])
 	return 0;
 }
 
+#ifdef CONFIG_CMD_SF_TEST
+enum {
+	STAGE_ERASE,
+	STAGE_CHECK,
+	STAGE_WRITE,
+	STAGE_READ,
+
+	STAGE_COUNT,
+};
+
+static char *stage_name[STAGE_COUNT] = {
+	"erase",
+	"check",
+	"write",
+	"read",
+};
+
+struct test_info {
+	int stage;
+	int bytes;
+	unsigned base_ms;
+	unsigned time_ms[STAGE_COUNT];
+};
+
+static void show_time(struct test_info *test, int stage)
+{
+	uint64_t speed;	/* KiB/s */
+	int bps;	/* Bits per second */
+
+	speed = (long long)test->bytes * 1000;
+	do_div(speed, test->time_ms[stage] * 1024);
+	bps = speed * 8;
+
+	printf("%d %s: %d ticks, %d KiB/s %d.%03d Mbps\n", stage,
+	       stage_name[stage], test->time_ms[stage],
+	       (int)speed, bps / 1000, bps % 1000);
+}
+
+static void spi_test_next_stage(struct test_info *test)
+{
+	test->time_ms[test->stage] = get_timer(test->base_ms);
+	show_time(test, test->stage);
+	test->base_ms = get_timer(0);
+	test->stage++;
+}
+
+/**
+ * Run a test on the SPI flash
+ *
+ * @param flash		SPI flash to use
+ * @param buf		Source buffer for data to write
+ * @param len		Size of data to read/write
+ * @param offset	Offset within flash to check
+ * @param vbuf		Verification buffer
+ * @return 0 if ok, -1 on error
+ */
+static int spi_flash_test(struct spi_flash *flash, char *buf, ulong len,
+			   ulong offset, char *vbuf)
+{
+	struct test_info test;
+	int i;
+
+	printf("SPI flash test:\n");
+	memset(&test, '\0', sizeof(test));
+	test.base_ms = get_timer(0);
+	test.bytes = len;
+	if (spi_flash_erase(flash, offset, len)) {
+		printf("Erase failed\n");
+		return -1;
+	}
+	spi_test_next_stage(&test);
+
+	if (spi_flash_read(flash, offset, len, vbuf)) {
+		printf("Check read failed\n");
+		return -1;
+	}
+	for (i = 0; i < len; i++) {
+		if (vbuf[i] != 0xff) {
+			printf("Check failed at %d\n", i);
+			print_buffer(i, vbuf + i, 1, min(len - i, 0x40), 0);
+			return -1;
+		}
+	}
+	spi_test_next_stage(&test);
+
+	if (spi_flash_write(flash, offset, len, buf)) {
+		printf("Write failed\n");
+		return -1;
+	}
+	memset(vbuf, '\0', len);
+	spi_test_next_stage(&test);
+
+	if (spi_flash_read(flash, offset, len, vbuf)) {
+		printf("Read failed\n");
+		return -1;
+	}
+	spi_test_next_stage(&test);
+
+	for (i = 0; i < len; i++) {
+		if (buf[i] != vbuf[i]) {
+			printf("Verify failed at %d, good data:\n", i);
+			print_buffer(i, buf + i, 1, min(len - i, 0x40), 0);
+			printf("Bad data:\n");
+			print_buffer(i, vbuf + i, 1, min(len - i, 0x40), 0);
+			return -1;
+		}
+	}
+	printf("Test passed\n");
+	for (i = 0; i < STAGE_COUNT; i++)
+		show_time(&test, i);
+
+	return 0;
+}
+
+static int do_spi_flash_test(int argc, char * const argv[])
+{
+	unsigned long offset;
+	unsigned long len;
+	char *buf = (char *)CONFIG_SYS_TEXT_BASE;
+	char *endp;
+	char *vbuf;
+	int ret;
+
+	offset = simple_strtoul(argv[1], &endp, 16);
+	if (*argv[1] == 0 || *endp != 0)
+		return -1;
+	len = simple_strtoul(argv[2], &endp, 16);
+	if (*argv[2] == 0 || *endp != 0)
+		return -1;
+
+	vbuf = malloc(len);
+	if (!vbuf) {
+		printf("Cannot allocate memory\n");
+		return 1;
+	}
+	buf = malloc(len);
+	if (!buf) {
+		free(vbuf);
+		printf("Cannot allocate memory\n");
+		return 1;
+	}
+
+	memcpy(buf, (char *)CONFIG_SYS_TEXT_BASE, len);
+	ret = spi_flash_test(flash, buf, len, offset, vbuf);
+	free(vbuf);
+	free(buf);
+	if (ret) {
+		printf("Test failed\n");
+		return 1;
+	}
+
+	return 0;
+}
+#endif /* CONFIG_CMD_SF_TEST */
+
 static int do_spi_flash(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[])
 {
 	const char *cmd;
@@ -341,6 +497,10 @@ static int do_spi_flash(cmd_tbl_t *cmdtp, int flag, int argc, char * const argv[
 		ret = do_spi_flash_read_write(argc, argv);
 	else if (strcmp(cmd, "erase") == 0)
 		ret = do_spi_flash_erase(argc, argv);
+#ifdef CONFIG_CMD_SF_TEST
+	else if (!strcmp(cmd, "test"))
+		ret = do_spi_flash_test(argc, argv);
+#endif
 	else
 		ret = -1;
 
@@ -352,6 +512,13 @@ usage:
 	return CMD_RET_USAGE;
 }
 
+#ifdef CONFIG_CMD_SF_TEST
+#define SF_TEST_HELP "\nsf test offset len		" \
+		"- run a very basic destructive test"
+#else
+#define SF_TEST_HELP
+#endif
+
 U_BOOT_CMD(
 	sf,	5,	1,	do_spi_flash,
 	"SPI flash sub-system",
@@ -365,4 +532,5 @@ U_BOOT_CMD(
 	"				  `+len' round up `len' to block size\n"
 	"sf update addr offset len	- erase and write `len' bytes from memory\n"
 	"				  at `addr' to flash at `offset'"
+	SF_TEST_HELP
 );