board: cssi: Refactor EEPROM read

On cmpc885 board, the ethernet addresses are stored in an
EEPROM that is accessed through SPI.

A 3 bytes command is sent to the chip then the content
gets read. At the time being a single block access is
performed, ignoring the first 3 bytes read.

Reword the SPI transfer to first send 3 bytes then
receive the content of the EEPROM so that there don't be
3 dummy bytes at the beginning of the buffer.

And move the function into common.c so that it can be
reused by the board that will be added in a future patch.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>

3 files changed, 40 insertions, 31 deletions

diff --git a/board/cssi/cmpc885/cmpc885.c b/board/cssi/cmpc885/cmpc885.c
index 689d573075..8f67f9fc33 100644
--- a/board/cssi/cmpc885/cmpc885.c
+++ b/board/cssi/cmpc885/cmpc885.c
@@ -147,55 +147,28 @@ int checkboard(void)
 	return 0;
 }
 
-#define SPI_EEPROM_READ	0x03
 #define MAX_SPI_BYTES	0x20
 
-#define EE_OFF_MAC1	0x13
-#define EE_OFF_MAC2	0x19
+#define EE_OFF_MAC1	0x10
+#define EE_OFF_MAC2	0x16
 
 /* Reads MAC addresses from SPI EEPROM */
 static int setup_mac(void)
 {
-	struct udevice *eeprom;
-	struct spi_slave *slave;
-	char name[30], *str;
 	uchar din[MAX_SPI_BYTES];
-	uchar dout[MAX_SPI_BYTES] = {SPI_EEPROM_READ, 0, 0};
-	int bitlen = 256, cs = 0, mode = 0, bus = 0, ret;
+	int ret;
 	unsigned long ident = 0x08005120;
 
-	snprintf(name, sizeof(name), "generic_%d:%d", bus, cs);
-
-	str = strdup(name);
-	if (!str)
-		return -1;
-
-	ret = uclass_get_device(UCLASS_SPI, 0, &eeprom);
-	if (ret) {
-		printf("Could not enable Serial Peripheral Interface (SPI).\n");
-		return -1;
-	}
-
-	ret = _spi_get_bus_and_cs(bus, cs, 1000000, mode, "spi_generic_drv", str, &eeprom, &slave);
+	ret = read_eeprom(din, sizeof(din));
 	if (ret)
 		return ret;
 
-	ret = spi_claim_bus(slave);
-
-	ret = spi_xfer(slave, bitlen, dout, din, SPI_XFER_BEGIN | SPI_XFER_END);
-	if (ret) {
-		printf("Error %d during SPI transaction\n", ret);
-		return ret;
-	}
-
 	if (memcmp(din + EE_OFF_MAC1, &ident, sizeof(ident)) == 0)
 		eth_env_set_enetaddr("ethaddr", din + EE_OFF_MAC1);
 
 	if (memcmp(din + EE_OFF_MAC2, &ident, sizeof(ident)) == 0)
 		eth_env_set_enetaddr("eth1addr", din + EE_OFF_MAC2);
 
-	spi_release_bus(slave);
-
 	return 0;
 }
 
diff --git a/board/cssi/common/common.c b/board/cssi/common/common.c
index 71b35cc692..de68e23fcd 100644
--- a/board/cssi/common/common.c
+++ b/board/cssi/common/common.c
@@ -8,7 +8,11 @@
  * Common specific routines for the CS Group boards
  */
 
+#include <dm.h>
 #include <fdt_support.h>
+#include <spi.h>
+
+#define SPI_EEPROM_READ	0x03
 
 static int fdt_set_node_and_value(void *blob, char *node, const char *prop,
 				  void *var, int size)
@@ -60,3 +64,34 @@ void ft_cleanup(void *blob, unsigned long id, const char *prop, const char *comp
 
 	fdt_set_node_and_value(blob, "/", prop, &id, sizeof(uint32_t));
 }
+
+int read_eeprom(u8 *din, int len)
+{
+	struct udevice *eeprom;
+	struct spi_slave *slave;
+	uchar dout[3] = {SPI_EEPROM_READ, 0, 0};
+	int ret;
+
+	ret = uclass_get_device(UCLASS_SPI, 0, &eeprom);
+	if (ret)
+		return ret;
+
+	ret = _spi_get_bus_and_cs(0, 0, 1000000, 0, "spi_generic_drv",
+				  "generic_0:0", &eeprom, &slave);
+	if (ret)
+		return ret;
+
+	ret = spi_claim_bus(slave);
+
+	ret = spi_xfer(slave, sizeof(dout) << 3, dout, NULL, SPI_XFER_BEGIN);
+	if (ret)
+		return ret;
+
+	ret = spi_xfer(slave, len << 3, NULL, din, SPI_XFER_END);
+	if (ret)
+		return ret;
+
+	spi_release_bus(slave);
+
+	return 0;
+}
diff --git a/board/cssi/common/common.h b/board/cssi/common/common.h
index 16852b6076..9660898cc9 100644
--- a/board/cssi/common/common.h
+++ b/board/cssi/common/common.h
@@ -4,5 +4,6 @@
 #define _BOARD_CSSI_COMMON_H
 
 void ft_cleanup(void *blob, unsigned long id, const char *prop, const char *compatible);
+int read_eeprom(u8 *din, int len);
 
 #endif /* _BOARD_CSSI_COMMON_H */