espi flash read returns invalid data if the read length is more than 0xFFFA
bytes, it supports maximum transaction of 2^16 bytes at a time, resister
spcom[TRANLEN] is 16 bits. If the transaction length is greater than 0xFFFF,
it need to be split into multiple transactions.
Signed-off-by: Shaohui Xie <b21...@freescale.com>
Cc: Mike Frysinger <vap...@gentoo.org>
---
changes for v2:
fix some compile warnings.
remove ifdef and use if else instead.
changes for v3:
rebased on first patch.
drivers/mtd/spi/spi_flash.c | 39 +++++++++++++++++++++++++++++++++++----
drivers/spi/fsl_espi.c | 6 ++++++
include/spi.h | 2 ++
3 files changed, 43 insertions(+), 4 deletions(-)
diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index c75b716..f90ef25 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -1,6 +1,7 @@
/*
* SPI flash interface
*
+ * Copyright 2009-2011 Freescale Semiconductor, Inc.
* Copyright (C) 2008 Atmel Corporation
* Copyright (C) 2010 Reinhard Meyer, EMK Elektronik
*
@@ -82,11 +83,41 @@ int spi_flash_cmd_read_fast(struct spi_flash *flash, u32
offset,
{
u8 cmd[5];
- cmd[0] = CMD_READ_ARRAY_FAST;
- spi_flash_addr(offset, cmd);
- cmd[4] = 0x00;
+ if (len <= flash->spi->max_transfer_length) {
+ cmd[0] = CMD_READ_ARRAY_FAST;
+ spi_flash_addr(offset, cmd);
+ cmd[4] = 0x00;
+
+ return spi_flash_read_common(flash, cmd, sizeof(cmd), data,
len);
+ } else {
+ int max_tran_len, num_chunks, tran_len, ret = 0;
+
+ max_tran_len = flash->spi->max_transfer_length;
+ num_chunks = len / max_tran_len + (len % max_tran_len ? 1 : 0);
+
+ while (num_chunks--) {
+ tran_len = min(len , max_tran_len);
+
+ cmd[0] = CMD_READ_ARRAY_FAST;
+ spi_flash_addr(offset, cmd);
+ cmd[4] = 0x00;
+
+ debug("READ: 0x%x => cmd = "
+ "{ 0x%02x 0x%02x%02x%02x%02x } tran_len = 0x%x\n",
+ offset, cmd[0], cmd[1], cmd[2], cmd[3], cmd[4],
tran_len);
- return spi_flash_read_common(flash, cmd, sizeof(cmd), data, len);
+ ret = spi_flash_read_common(
+ flash, cmd, sizeof(cmd), data, tran_len);
+ if (ret < 0)
+ return ret;
+
+ offset += max_tran_len;
+ data += max_tran_len;
+ len -= max_tran_len;
+ }
+
+ return ret;
+ }
}
int spi_flash_cmd_poll_bit(struct spi_flash *flash, unsigned long timeout,
diff --git a/drivers/spi/fsl_espi.c b/drivers/spi/fsl_espi.c
index 55b29cc..5ed6a59 100644
--- a/drivers/spi/fsl_espi.c
+++ b/drivers/spi/fsl_espi.c
@@ -53,6 +53,8 @@
ESPI_CSMODE_CSBEF(0) | ESPI_CSMODE_CSAFT(0) | \
ESPI_CSMODE_CSCG(1))
+#define ESPI_MAX_DATA_TRANSFER_LEN 0xFFF0
+
struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int mode)
{
@@ -71,6 +73,7 @@ struct spi_slave *spi_setup_slave(unsigned int bus, unsigned
int cs,
slave->bus = bus;
slave->cs = cs;
slave->slave_data.mode = mode;
+ slave->max_transfer_length = ESPI_MAX_DATA_TRANSFER_LEN;
/* Set eSPI BRG clock source */
get_sys_info(&sysinfo);
@@ -174,6 +177,9 @@ int spi_xfer(struct spi_slave *slave, unsigned int bitlen,
const void *data_out,
u8 *cmd_buf = slave->slave_data.cmd_buf;
size_t cmd_len = slave->slave_data.cmd_len;
+ if (slave->max_transfer_length > ESPI_MAX_DATA_TRANSFER_LEN)
+ return -1;
+
switch (flags) {
case SPI_XFER_BEGIN:
cmd_len = slave->slave_data.cmd_len = bitlen / 8;
diff --git a/include/spi.h b/include/spi.h
index 213f6e6..c2c0d36 100644
--- a/include/spi.h
+++ b/include/spi.h
@@ -70,11 +70,13 @@ struct spi_slave_data {
* bus: ID of the bus that the slave is attached to.
* cs: ID of the chip select connected to the slave.
* slave_data: slave data for hardware and transfer.
+ * max_transfer_length: maximum data transfer length supported by the slave.
*/
struct spi_slave {
unsigned int bus;
unsigned int cs;
struct spi_slave_data slave_data;
+ unsigned int max_transfer_length;
};
/*-----------------------------------------------------------------------
--
1.6.4
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