4 files changed, 37 insertions, 31 deletions

diff --git a/src/drivers/spi/spi_flash.c b/src/drivers/spi/spi_flash.c
index d737ee9e61..607fb214a8 100644
--- a/src/drivers/spi/spi_flash.c
+++ b/src/drivers/spi/spi_flash.c
@@ -79,8 +79,8 @@ int spi_flash_cmd(struct spi_slave *spi, u8 cmd, void *response, size_t len)
 	return ret;
 }
 
-int spi_flash_cmd_read(struct spi_slave *spi, const u8 *cmd,
-		size_t cmd_len, void *data, size_t data_len)
+static int spi_flash_cmd_read(struct spi_slave *spi, const u8 *cmd,
+			      size_t cmd_len, void *data, size_t data_len)
 {
 	int ret = do_spi_flash_cmd(spi, cmd, cmd_len, data, data_len);
 	if (ret) {
@@ -108,41 +108,51 @@ int spi_flash_cmd_write(struct spi_slave *spi, const u8 *cmd, size_t cmd_len,
 	return ret;
 }
 
-int spi_flash_read_common(struct spi_flash *flash, const u8 *cmd,
-		size_t cmd_len, void *data, size_t data_len)
+static int spi_flash_cmd_read_array(struct spi_slave *spi, u8 *cmd,
+				    size_t cmd_len, u32 offset,
+				    size_t len, void *data)
 {
-	struct spi_slave *spi = flash->spi;
-	int ret;
+	while (len) {
+		size_t transfer_size;
 
-	spi->rw = SPI_READ_FLAG;
-	ret = spi_flash_cmd_read(spi, cmd, cmd_len, data, data_len);
+		if (spi->max_transfer_size)
+			transfer_size = min(len, spi->max_transfer_size);
+		else
+			transfer_size = len;
 
-	return ret;
+		spi_flash_addr(offset, cmd);
+
+		if (spi_flash_cmd_read(spi, cmd, cmd_len, data, transfer_size))
+			break;
+
+		offset += transfer_size;
+		data = (void *)((uintptr_t)data + transfer_size);
+		len -= transfer_size;
+	}
+
+	return len != 0;
 }
 
 int spi_flash_cmd_read_fast(struct spi_flash *flash, u32 offset,
 		size_t len, void *data)
 {
-	struct spi_slave *spi = flash->spi;
 	u8 cmd[5];
 
 	cmd[0] = CMD_READ_ARRAY_FAST;
-	spi_flash_addr(offset, cmd);
 	cmd[4] = 0x00;
 
-	return spi_flash_cmd_read(spi, cmd, sizeof(cmd), data, len);
+	return spi_flash_cmd_read_array(flash->spi, cmd, sizeof(cmd),
+					offset, len, data);
 }
 
 int spi_flash_cmd_read_slow(struct spi_flash *flash, u32 offset,
-		size_t len, void *data)
+			    size_t len, void *data)
 {
-	struct spi_slave *spi = flash->spi;
 	u8 cmd[4];
 
 	cmd[0] = CMD_READ_ARRAY_SLOW;
-	spi_flash_addr(offset, cmd);
-
-	return spi_flash_cmd_read(spi, cmd, sizeof(cmd), data, len);
+	return spi_flash_cmd_read_array(flash->spi, cmd, sizeof(cmd),
+					offset, len, data);
 }
 
 int spi_flash_cmd_poll_bit(struct spi_flash *flash, unsigned long timeout,
diff --git a/src/drivers/spi/spi_flash_internal.h b/src/drivers/spi/spi_flash_internal.h
index 6f184848b6..4798b10925 100644
--- a/src/drivers/spi/spi_flash_internal.h
+++ b/src/drivers/spi/spi_flash_internal.h
@@ -32,13 +32,6 @@
 /* Send a single-byte command to the device and read the response */
 int spi_flash_cmd(struct spi_slave *spi, u8 cmd, void *response, size_t len);
 
-/*
- * Send a multi-byte command to the device and read the response. Used
- * for flash array reads, etc.
- */
-int spi_flash_cmd_read(struct spi_slave *spi, const u8 *cmd,
-		size_t cmd_len, void *data, size_t data_len);
-
 int spi_flash_cmd_read_fast(struct spi_flash *flash, u32 offset,
 		size_t len, void *data);
 
@@ -52,13 +45,6 @@ int spi_flash_cmd_read_slow(struct spi_flash *flash, u32 offset,
 int spi_flash_cmd_write(struct spi_slave *spi, const u8 *cmd, size_t cmd_len,
 		const void *data, size_t data_len);
 
-/*
- * Same as spi_flash_cmd_read() except it also claims/releases the SPI
- * bus. Used as common part of the ->read() operation.
- */
-int spi_flash_read_common(struct spi_flash *flash, const u8 *cmd,
-		size_t cmd_len, void *data, size_t data_len);
-
 /* Send a command to the device and wait for some bit to clear itself. */
 int spi_flash_cmd_poll_bit(struct spi_flash *flash, unsigned long timeout,
 			   u8 cmd, u8 poll_bit);
diff --git a/src/include/spi-generic.h b/src/include/spi-generic.h
index bd0020f5d2..4de138cf09 100644
--- a/src/include/spi-generic.h
+++ b/src/include/spi-generic.h
@@ -43,11 +43,16 @@
  *   bus:	ID of the bus that the slave is attached to.
  *   cs:	ID of the chip select connected to the slave.
  *   rw: 	Read or Write flag
+ *   max_transfer_size: maximum amount of bytes which can be sent in a single
+ *              read or write transaction, usually this is a controller
+ *              property, kept in the slave structure for convenience. Zero in
+ *              this field means 'unlimited'.
  */
 struct spi_slave {
 	unsigned int	bus;
 	unsigned int	cs;
 	unsigned int	rw;
+	unsigned int	max_transfer_size;
 	int force_programmer_specific;
 	struct spi_flash * (*programmer_specific_probe) (struct spi_slave *spi);
 };
diff --git a/src/soc/imgtec/pistachio/spi.c b/src/soc/imgtec/pistachio/spi.c
index 69682d0456..5522f2408e 100644
--- a/src/soc/imgtec/pistachio/spi.c
+++ b/src/soc/imgtec/pistachio/spi.c
@@ -25,6 +25,9 @@
 #error "Unsupported SPI driver API"
 #endif
 
+/* Imgtec controller uses 16 bit packet length. */
+#define IMGTEC_SPI_MAX_TRANSFER_SIZE   ((1 << 16) - 1)
+
 struct img_spi_slave {
 	struct spi_slave slave;
 	/* SPIM instance device parameters */
@@ -441,6 +444,8 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs)
 	slave->bus = bus;
 	slave->cs = cs;
 	slave->rw = SPI_READ_FLAG | SPI_WRITE_FLAG;
+	slave->max_transfer_size = IMGTEC_SPI_MAX_TRANSFER_SIZE;
+
 	device_parameters->bitrate = 64;
 	device_parameters->cs_setup = 0;
 	device_parameters->cs_hold = 0;