drivers/spi: Re-factor spi_crop_chunk

spi_crop_chunk is a property of the SPI controller since it depends
upon the maximum transfer size that is supported by the
controller. Also, it is possible to implement this within spi-generic
layer by obtaining following parameters from the controller:

1. max_xfer_size: Maximum transfer size supported by the controller
(Size of 0 indicates invalid size, and unlimited transfer size is
indicated by UINT32_MAX.)

2. deduct_cmd_len: Whether cmd_len needs to be deducted from the
max_xfer_size to determine max data size that can be
transferred. (This is used by the amd boards.)

Change-Id: I81c199413f879c664682088e93bfa3f91c6a46e5
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/19386
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Tested-by: coreboot org <coreboot.org@gmail.com>

src/drivers/spi/adesto.c

@@ -97,7 +97,7 @@ static int adesto_write(const struct spi_flash *flash, u32 offset, size_t len,
 	for (actual = 0; actual < len; actual += chunk_len) {
 		byte_addr = offset % page_size;
 		chunk_len = min(len - actual, page_size - byte_addr);
-		chunk_len = spi_crop_chunk(sizeof(cmd), chunk_len);
+		chunk_len = spi_crop_chunk(&flash->spi, sizeof(cmd), chunk_len);
 
 		cmd[0] = CMD_AT25DF_PP;
 		cmd[1] = (offset >> 16) & 0xff;

src/drivers/spi/amic.c

@@ -79,7 +79,7 @@ static int amic_write(const struct spi_flash *flash, u32 offset, size_t len,
 
 	for (actual = 0; actual < len; actual += chunk_len) {
 		chunk_len = min(len - actual, page_size - byte_addr);
-		chunk_len = spi_crop_chunk(sizeof(cmd), chunk_len);
+		chunk_len = spi_crop_chunk(&flash->spi, sizeof(cmd), chunk_len);
 
 		cmd[0] = CMD_A25_PP;
 		cmd[1] = (offset >> 16) & 0xff;

src/drivers/spi/atmel.c

@@ -125,7 +125,7 @@ static int atmel_write(const struct spi_flash *flash, u32 offset, size_t len,
 	for (actual = 0; actual < len; actual += chunk_len) {
 		byte_addr = offset % page_size;
 		chunk_len = min(len - actual, page_size - byte_addr);
-		chunk_len = spi_crop_chunk(sizeof(cmd), chunk_len);
+		chunk_len = spi_crop_chunk(&flash->spi, sizeof(cmd), chunk_len);
 
 		cmd[0] = CMD_AT25_PP;
 		cmd[1] = (offset >> 16) & 0xff;

src/drivers/spi/eon.c

@@ -95,7 +95,7 @@ static int eon_write(const struct spi_flash *flash,
 	for (actual = 0; actual < len; actual += chunk_len) {
 		byte_addr = offset % page_size;
 		chunk_len = min(len - actual, page_size - byte_addr);
-		chunk_len = spi_crop_chunk(sizeof(cmd), chunk_len);
+		chunk_len = spi_crop_chunk(&flash->spi, sizeof(cmd), chunk_len);
 
 		ret = spi_flash_cmd(&flash->spi, CMD_EN25_WREN, NULL, 0);
 		if (ret < 0) {

src/drivers/spi/gigadevice.c

@@ -136,7 +136,7 @@ static int gigadevice_write(const struct spi_flash *flash, u32 offset,
 	for (actual = 0; actual < len; actual += chunk_len) {
 		byte_addr = offset % page_size;
 		chunk_len = min(len - actual, page_size - byte_addr);
-		chunk_len = spi_crop_chunk(sizeof(cmd), chunk_len);
+		chunk_len = spi_crop_chunk(&flash->spi, sizeof(cmd), chunk_len);
 
 		ret = spi_flash_cmd(&flash->spi, CMD_GD25_WREN, NULL, 0);
 		if (ret < 0) {

src/drivers/spi/macronix.c

@@ -164,7 +164,7 @@ static int macronix_write(const struct spi_flash *flash, u32 offset, size_t len,
 	for (actual = 0; actual < len; actual += chunk_len) {
 		byte_addr = offset % page_size;
 		chunk_len = min(len - actual, page_size - byte_addr);
-		chunk_len = spi_crop_chunk(sizeof(cmd), chunk_len);
+		chunk_len = spi_crop_chunk(&flash->spi, sizeof(cmd), chunk_len);
 
 		cmd[0] = CMD_MX25XX_PP;
 		cmd[1] = (offset >> 16) & 0xff;

src/drivers/spi/spansion.c

@@ -217,7 +217,7 @@ static int spansion_write(const struct spi_flash *flash, u32 offset, size_t len,
 	for (actual = 0; actual < len; actual += chunk_len) {
 		byte_addr = offset % page_size;
 		chunk_len = min(len - actual, page_size - byte_addr);
-		chunk_len = spi_crop_chunk(sizeof(cmd), chunk_len);
+		chunk_len = spi_crop_chunk(&flash->spi, sizeof(cmd), chunk_len);
 
 		cmd[0] = CMD_S25FLXX_PP;
 		cmd[1] = (offset >> 16) & 0xff;

src/drivers/spi/spi-generic.c

@@ -88,6 +88,25 @@ int spi_xfer(const struct spi_slave *slave, const void *dout, size_t bytesout,
 	return -1;
 }
 
+unsigned int spi_crop_chunk(const struct spi_slave *slave, unsigned int cmd_len,
+			unsigned int buf_len)
+{
+	const struct spi_ctrlr *ctrlr = slave->ctrlr;
+	unsigned int ctrlr_max;
+
+	if (!ctrlr)
+		return 0;
+
+	ctrlr_max = ctrlr->max_xfer_size;
+
+	assert (ctrlr_max != 0);
+
+	if (ctrlr->deduct_cmd_len && (ctrlr_max > cmd_len))
+		ctrlr_max -= cmd_len;
+
+	return min(ctrlr_max, buf_len);
+}
+
 void __attribute__((weak)) spi_init(void)
 {
 	/* Default weak implementation - do nothing. */

src/drivers/spi/spiconsole.c

@@ -46,7 +46,7 @@ void spiconsole_tx_byte(unsigned char c) {
 	};
 
 	/* Verify the spi buffer is big enough to send even a single byte */
-	if (spi_crop_chunk(0,MAX_MSG_LENGTH) <
+	if (spi_crop_chunk(&slave, 0, MAX_MSG_LENGTH) <
 			sizeof(struct em100_msg_header) + 1)
 		return;
 
@@ -55,7 +55,7 @@ void spiconsole_tx_byte(unsigned char c) {
 
 	/* Send the data on newline or when the max spi length is reached */
 	if (c == '\n' || (sizeof(struct em100_msg_header) +
-			msg.header.msg_length == spi_crop_chunk(0,
+			msg.header.msg_length == spi_crop_chunk(&slave, 0,
 			MAX_MSG_LENGTH))) {
 		spi_xfer(&slave, &msg, sizeof(struct em100_msg_header) +
 				msg.header.msg_length, NULL, 0);

src/drivers/spi/sst.c

@@ -194,7 +194,7 @@ static int sst_write_256(const struct spi_flash *flash, u32 offset, size_t len,
 	for (actual = 0; actual < len; actual += chunk_len) {
 		byte_addr = offset % page_size;
 		chunk_len = min(len - actual, page_size - byte_addr);
-		chunk_len = spi_crop_chunk(sizeof(cmd), chunk_len);
+		chunk_len = spi_crop_chunk(&flash->spi, sizeof(cmd), chunk_len);
 
 		cmd[0] = CMD_SST_BP;
 		cmd[1] = (offset >> 16) & 0xff;

src/drivers/spi/stmicro.c

@@ -193,7 +193,7 @@ static int stmicro_write(const struct spi_flash *flash,
 	for (actual = 0; actual < len; actual += chunk_len) {
 		byte_addr = offset % page_size;
 		chunk_len = min(len - actual, page_size - byte_addr);
-		chunk_len = spi_crop_chunk(sizeof(cmd), chunk_len);
+		chunk_len = spi_crop_chunk(&flash->spi, sizeof(cmd), chunk_len);
 
 		cmd[0] = CMD_M25PXX_PP;
 		cmd[1] = (offset >> 16) & 0xff;

src/drivers/spi/winbond.c

@@ -155,7 +155,7 @@ static int winbond_write(const struct spi_flash *flash, u32 offset, size_t len,
 	for (actual = 0; actual < len; actual += chunk_len) {
 		byte_addr = offset % page_size;
 		chunk_len = min(len - actual, page_size - byte_addr);
-		chunk_len = spi_crop_chunk(sizeof(cmd), chunk_len);
+		chunk_len = spi_crop_chunk(&flash->spi, sizeof(cmd), chunk_len);
 
 		cmd[0] = CMD_W25_PP;
 		cmd[1] = (offset >> 16) & 0xff;