dm: i2c: EEPROM simulator allow tests visibility of addr and offset

Improve i2c EEPROM simulator testing by providing access functions to
check the previous chip addr and offset.

Given that we can now directly test the offsets, also simplified the
offset mapping and allow for wrapping acceses.

Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
Reviewed-by: Heiko Schocher <hs@denx.de>

3 files changed, 86 insertions, 29 deletions

diff --git a/arch/sandbox/include/asm/test.h b/arch/sandbox/include/asm/test.h
index b885e1a14f..f3a8b455d5 100644
--- a/arch/sandbox/include/asm/test.h
+++ b/arch/sandbox/include/asm/test.h
@@ -72,6 +72,10 @@ void sandbox_i2c_eeprom_set_test_mode(struct udevice *dev,
 
 void sandbox_i2c_eeprom_set_offset_len(struct udevice *dev, int offset_len);
 
+uint sanbox_i2c_eeprom_get_prev_addr(struct udevice *dev);
+
+uint sanbox_i2c_eeprom_get_prev_offset(struct udevice *dev);
+
 /**
  * sandbox_i2c_rtc_set_offset() - set the time offset from system/base time
  *
diff --git a/drivers/misc/i2c_eeprom_emul.c b/drivers/misc/i2c_eeprom_emul.c
index 29ed45923f..284267f2ea 100644
--- a/drivers/misc/i2c_eeprom_emul.c
+++ b/drivers/misc/i2c_eeprom_emul.c
@@ -27,6 +27,8 @@ struct sandbox_i2c_flash_plat_data {
 
 struct sandbox_i2c_flash {
 	uint8_t *data;
+	uint prev_addr;		/* slave address of previous access */
+	uint prev_offset;	/* offset of previous access */
 };
 
 void sandbox_i2c_eeprom_set_test_mode(struct udevice *dev,
@@ -44,6 +46,20 @@ void sandbox_i2c_eeprom_set_offset_len(struct udevice *dev, int offset_len)
 	plat->offset_len = offset_len;
 }
 
+uint sanbox_i2c_eeprom_get_prev_addr(struct udevice *dev)
+{
+	struct sandbox_i2c_flash *priv = dev_get_priv(dev);
+
+	return priv->prev_addr;
+}
+
+uint sanbox_i2c_eeprom_get_prev_offset(struct udevice *dev)
+{
+	struct sandbox_i2c_flash *priv = dev_get_priv(dev);
+
+	return priv->prev_offset;
+}
+
 static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
 				  int nmsgs)
 {
@@ -52,6 +68,10 @@ static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
 
 	debug("\n%s\n", __func__);
 	debug_buffer(0, priv->data, 1, 16, 0);
+
+	/* store addr for testing visibity */
+	priv->prev_addr = msg->addr;
+
 	for (; nmsgs > 0; nmsgs--, msg++) {
 		struct sandbox_i2c_flash_plat_data *plat =
 				dev_get_platdata(emul);
@@ -60,11 +80,6 @@ static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
 
 		if (!plat->size)
 			return -ENODEV;
-		if (msg->addr + msg->len > plat->size) {
-			debug("%s: Address %x, len %x is outside range 0..%x\n",
-			      __func__, msg->addr, msg->len, plat->size);
-			return -EINVAL;
-		}
 		len = msg->len;
 		debug("   %s: msg->len=%d",
 		      msg->flags & I2C_M_RD ? "read" : "write",
@@ -73,7 +88,16 @@ static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
 			if (plat->test_mode == SIE_TEST_MODE_SINGLE_BYTE)
 				len = 1;
 			debug(", offset %x, len %x: ", offset, len);
-			memcpy(msg->buf, priv->data + offset, len);
+			if (offset + len > plat->size) {
+				int overflow = offset + len - plat->size;
+				int initial = len - overflow;
+
+				memcpy(msg->buf, priv->data + offset, initial);
+				memcpy(msg->buf + initial, priv->data,
+				       overflow);
+			} else {
+				memcpy(msg->buf, priv->data + offset, len);
+			}
 			memset(msg->buf + len, '\xff', msg->len - len);
 			debug_buffer(0, msg->buf, 1, msg->len, 0);
 		} else if (len >= plat->offset_len) {
@@ -87,15 +111,24 @@ static int sandbox_i2c_eeprom_xfer(struct udevice *emul, struct i2c_msg *msg,
 			if (plat->test_mode == SIE_TEST_MODE_SINGLE_BYTE)
 				len = min(len, 1);
 
-			/* For testing, map offsets into our limited buffer */
-			for (i = 24; i > 0; i -= 8) {
-				if (offset > (1 << i)) {
-					offset = (offset >> i) |
-						(offset & ((1 << i) - 1));
-					offset += i;
-				}
+			/* store offset for testing visibility */
+			priv->prev_offset = offset;
+
+			/* For testing, map offsets into our limited buffer.
+			 * offset wraps every 256 bytes
+			 */
+			offset &= 0xff;
+			debug("mapped offset to %x\n", offset);
+
+			if (offset + len > plat->size) {
+				int overflow = offset + len - plat->size;
+				int initial = len - overflow;
+
+				memcpy(priv->data + offset, ptr, initial);
+				memcpy(priv->data, ptr + initial, overflow);
+			} else {
+				memcpy(priv->data + offset, ptr, len);
 			}
-			memcpy(priv->data + offset, ptr, len);
 		}
 	}
 	debug_buffer(0, priv->data, 1, 16, 0);
diff --git a/test/dm/i2c.c b/test/dm/i2c.c
index cbbd4aa29a..bf5597b7a6 100644
--- a/test/dm/i2c.c
+++ b/test/dm/i2c.c
@@ -15,6 +15,7 @@
 #include <dm/test.h>
 #include <dm/uclass-internal.h>
 #include <dm/util.h>
+#include <hexdump.h>
 #include <test/ut.h>
 
 static const int busnum;
@@ -185,35 +186,54 @@ static int dm_test_i2c_offset(struct unit_test_state *uts)
 	ut_assertok(i2c_set_chip_offset_len(dev, 0));
 	ut_assertok(dm_i2c_write(dev, 10 /* ignored */, (uint8_t *)"AB", 2));
 	ut_assertok(dm_i2c_read(dev, 0, buf, 5));
-	ut_assertok(memcmp(buf, "AB\0\0\0\0", sizeof(buf)));
+	ut_asserteq_mem("AB\0\0\0\0", buf, sizeof(buf));
+	ut_asserteq(0, sanbox_i2c_eeprom_get_prev_offset(eeprom));
 
 	/* Offset length 1 */
 	sandbox_i2c_eeprom_set_offset_len(eeprom, 1);
 	ut_assertok(i2c_set_chip_offset_len(dev, 1));
 	ut_assertok(dm_i2c_write(dev, 2, (uint8_t *)"AB", 2));
+	ut_asserteq(2, sanbox_i2c_eeprom_get_prev_offset(eeprom));
 	ut_assertok(dm_i2c_read(dev, 0, buf, 5));
-	ut_assertok(memcmp(buf, "ABAB\0", sizeof(buf)));
+	ut_asserteq_mem("ABAB\0", buf, sizeof(buf));
+	ut_asserteq(0, sanbox_i2c_eeprom_get_prev_offset(eeprom));
 
-	/* Offset length 2 */
+	/* Offset length 2 boundary - check model wrapping */
 	sandbox_i2c_eeprom_set_offset_len(eeprom, 2);
 	ut_assertok(i2c_set_chip_offset_len(dev, 2));
-	ut_assertok(dm_i2c_write(dev, 0x210, (uint8_t *)"AB", 2));
-	ut_assertok(dm_i2c_read(dev, 0x210, buf, 5));
-	ut_assertok(memcmp(buf, "AB\0\0\0", sizeof(buf)));
+	ut_assertok(dm_i2c_write(dev, 0xFF, (uint8_t *)"A", 1));
+	ut_asserteq(0xFF, sanbox_i2c_eeprom_get_prev_offset(eeprom));
+	ut_assertok(dm_i2c_write(dev, 0x100, (uint8_t *)"B", 1));
+	ut_asserteq(0x100, sanbox_i2c_eeprom_get_prev_offset(eeprom));
+	ut_assertok(dm_i2c_write(dev, 0x101, (uint8_t *)"C", 1));
+	ut_asserteq(0x101, sanbox_i2c_eeprom_get_prev_offset(eeprom));
+	ut_assertok(dm_i2c_read(dev, 0xFF, buf, 5));
+	ut_asserteq_mem("ABCAB", buf, sizeof(buf));
+	ut_asserteq(0xFF, sanbox_i2c_eeprom_get_prev_offset(eeprom));
 
-	/* Offset length 3 */
+	/* Offset length 2 */
 	sandbox_i2c_eeprom_set_offset_len(eeprom, 2);
 	ut_assertok(i2c_set_chip_offset_len(dev, 2));
-	ut_assertok(dm_i2c_write(dev, 0x410, (uint8_t *)"AB", 2));
-	ut_assertok(dm_i2c_read(dev, 0x410, buf, 5));
-	ut_assertok(memcmp(buf, "AB\0\0\0", sizeof(buf)));
+	ut_assertok(dm_i2c_write(dev, 0x2020, (uint8_t *)"AB", 2));
+	ut_assertok(dm_i2c_read(dev, 0x2020, buf, 5));
+	ut_asserteq_mem("AB\0\0\0", buf, sizeof(buf));
+	ut_asserteq(0x2020, sanbox_i2c_eeprom_get_prev_offset(eeprom));
+
+	/* Offset length 3 */
+	sandbox_i2c_eeprom_set_offset_len(eeprom, 3);
+	ut_assertok(i2c_set_chip_offset_len(dev, 3));
+	ut_assertok(dm_i2c_write(dev, 0x303030, (uint8_t *)"AB", 2));
+	ut_assertok(dm_i2c_read(dev, 0x303030, buf, 5));
+	ut_asserteq_mem("AB\0\0\0", buf, sizeof(buf));
+	ut_asserteq(0x303030, sanbox_i2c_eeprom_get_prev_offset(eeprom));
 
 	/* Offset length 4 */
-	sandbox_i2c_eeprom_set_offset_len(eeprom, 2);
-	ut_assertok(i2c_set_chip_offset_len(dev, 2));
-	ut_assertok(dm_i2c_write(dev, 0x420, (uint8_t *)"AB", 2));
-	ut_assertok(dm_i2c_read(dev, 0x420, buf, 5));
-	ut_assertok(memcmp(buf, "AB\0\0\0", sizeof(buf)));
+	sandbox_i2c_eeprom_set_offset_len(eeprom, 4);
+	ut_assertok(i2c_set_chip_offset_len(dev, 4));
+	ut_assertok(dm_i2c_write(dev, 0x40404040, (uint8_t *)"AB", 2));
+	ut_assertok(dm_i2c_read(dev, 0x40404040, buf, 5));
+	ut_asserteq_mem("AB\0\0\0", buf, sizeof(buf));
+	ut_asserteq(0x40404040, sanbox_i2c_eeprom_get_prev_offset(eeprom));
 
 	/* Restore defaults */
 	sandbox_i2c_eeprom_set_offset_len(eeprom, 1);