[coreboot-gerrit] Patch set updated for coreboot: spi: Get rid of max_transfer_size parameter in spi_slave structure

[Furquan Shaikh (furquan@google.com)]

Furquan Shaikh (furquan at google.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/17463

-gerrit

commit 05e29f39dcd98f5b47031cc67926cc5eaa1a23d9
Author: Furquan Shaikh <furquan at chromium.org>
Date:   Thu Nov 17 16:17:37 2016 -0800

    spi: Get rid of max_transfer_size parameter in spi_slave structure
    
    max_transfer_size is a property of the SPI controller and not of the spi
    slave. Also, this is used only on one SoC currently. There is no need to
    handle this at the spi flash layer.
    
    This change moves the handling of max_transfer_size to SoC SPI driver
    and gets rid of the max_transfer_size parameter.
    
    BUG=None
    BRANCH=None
    TEST=Compiles successfully.
    
    Change-Id: I19a1d0a83395a58c2bc1614b24518a3220945a60
    Signed-off-by: Furquan Shaikh <furquan at chromium.org>
---
 src/drivers/spi/spi_flash.c    | 21 ++--------------
 src/include/spi-generic.h      |  5 ----
 src/soc/imgtec/pistachio/spi.c | 57 ++++++++++++++++++++++++++++++++----------
 3 files changed, 46 insertions(+), 37 deletions(-)

diff --git a/src/drivers/spi/spi_flash.c b/src/drivers/spi/spi_flash.c
index 7ca6822..baa1f1a 100644
--- a/src/drivers/spi/spi_flash.c
+++ b/src/drivers/spi/spi_flash.c
@@ -123,25 +123,8 @@ static int spi_flash_cmd_read_array(struct spi_slave *spi, u8 *cmd,
 				    size_t cmd_len, u32 offset,
 				    size_t len, void *data)
 {
-	while (len) {
-		size_t transfer_size;
-
-		if (spi->max_transfer_size)
-			transfer_size = min(len, spi->max_transfer_size);
-		else
-			transfer_size = len;
-
-		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;
+	spi_flash_addr(offset, cmd);
+	return spi_flash_cmd_read(spi, cmd, cmd_len, data, len);
 }
 
 int spi_flash_cmd_read_fast(const struct spi_flash *flash, u32 offset,
diff --git a/src/include/spi-generic.h b/src/include/spi-generic.h
index ee02394..eacb092 100644
--- a/src/include/spi-generic.h
+++ b/src/include/spi-generic.h
@@ -31,15 +31,10 @@
  *
  *   bus:	ID of the bus that the slave is attached to.
  *   cs:	ID of the chip select connected to the slave.
- *   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	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 87dd66f..2b4b01c 100644
--- a/src/soc/imgtec/pistachio/spi.c
+++ b/src/soc/imgtec/pistachio/spi.c
@@ -445,7 +445,6 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs)
 	img_slave->base = base;
 	slave->bus = bus;
 	slave->cs = cs;
-	slave->max_transfer_size = IMGTEC_SPI_MAX_TRANSFER_SIZE;
 
 	device_parameters->bitrate = 64;
 	device_parameters->cs_setup = 0;
@@ -509,22 +508,12 @@ void spi_release_bus(struct spi_slave *slave)
 }
 
 /* SPI transfer */
-int spi_xfer(struct spi_slave *slave, const void *dout, unsigned int bytesout,
-		void *din, unsigned int bytesin)
+static int do_spi_xfer(struct spi_slave *slave, const void *dout,
+		       unsigned int bytesout, void *din, unsigned int bytesin)
 {
 	struct spim_buffer	buff_0;
 	struct spim_buffer	buff_1;
 
-	if (!slave) {
-		printk(BIOS_ERR, "%s: Error: slave was not set up.\n",
-				__func__);
-		return -SPIM_API_NOT_INITIALISED;
-	}
-	if (!dout && !din) {
-		printk(BIOS_ERR, "%s: Error: both buffers are NULL.\n",
-				__func__);
-			return -SPIM_INVALID_TRANSFER_DESC;
-	}
 	/* If we only have a read or a write operation
 	 * the parameters for it will be put in the first buffer
 	 */
@@ -543,6 +532,48 @@ int spi_xfer(struct spi_slave *slave, const void *dout, unsigned int bytesout,
 	return spim_io(slave, &buff_0, (dout && din) ? &buff_1 : NULL);
 }
 
+int spi_xfer(struct spi_slave *slave, const void *dout, unsigned int bytesout,
+	     void *din, unsigned int bytesin)
+{
+	unsigned int in_sz, out_sz;
+	int ret;
+
+	if (!slave) {
+		printk(BIOS_ERR, "%s: Error: slave was not set up.\n",
+				__func__);
+		return -SPIM_API_NOT_INITIALISED;
+	}
+	if (!dout && !din) {
+		printk(BIOS_ERR, "%s: Error: both buffers are NULL.\n",
+				__func__);
+			return -SPIM_INVALID_TRANSFER_DESC;
+	}
+
+	while (bytesin || bytesout) {
+		in_sz = min(IMGTEC_SPI_MAX_TRANSFER_SIZE, bytesin);
+		out_sz = min(IMGTEC_SPI_MAX_TRANSFER_SIZE, bytesout);
+
+		ret = do_spi_xfer(slave, dout, out_sz, din, in_sz);
+		if (ret)
+			return ret;
+
+		bytesin -= in_sz;
+		bytesout -= out_sz;
+
+		if (bytesin)
+			din += in_sz;
+		else
+			din = NULL;
+
+		if (bytesout)
+			dout += out_sz;
+		else
+			dout = NULL;
+	}
+
+	return SPIM_OK;
+}
+
 unsigned int spi_crop_chunk(unsigned int cmd_len, unsigned int buf_len)
 {
 	return min(IMGTEC_SPI_MAX_TRANSFER_SIZE, buf_len);