[U-Boot] [RFC] [PATCH 1/4] Support for 'single frame' spi flash commands
Can Aydin
can.aydin at locatacorp.com
Tue Sep 28 11:56:53 CEST 2010
Add a single-hit transaction to the spi flash framework.
Useful for when the hardware makes it impossible to maintain CS
state between disparate command and data calls by requiring a
'frame length' (thus pre-determining how many clock cycles the
CS will stay asserted).
Such is the case with the Freescale eSPI controller.
Signed-off-by: Can Aydin<can.aydin at locatacorp.com>
---
drivers/mtd/spi/spi_flash.c | 38 +++++++++++++++++++++++++++++++--
drivers/mtd/spi/spi_flash_internal.h | 9 ++++++++
2 files changed, 44 insertions(+), 3 deletions(-)
mode change 100644 => 100755 drivers/mtd/spi/spi_flash.c
mode change 100644 => 100755 drivers/mtd/spi/spi_flash_internal.h
diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
old mode 100644
new mode 100755
index ea875dc..7646fc5
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -70,12 +70,12 @@ int spi_flash_cmd_write(struct spi_slave *spi, const u8 *cmd, size_t cmd_len,
ret = spi_xfer(spi, cmd_len * 8, cmd, NULL, flags);
if (ret) {
- debug("SF: Failed to send read command (%zu bytes): %d\n",
+ debug("SF: Failed to send write command (%zu bytes): %d\n",
cmd_len, ret);
} else if (data_len != 0) {
ret = spi_xfer(spi, data_len * 8, data, NULL, SPI_XFER_END);
if (ret)
- debug("SF: Failed to read %zu bytes of data: %d\n",
+ debug("SF: Failed to write %zu bytes of data: %d\n",
data_len, ret);
}
@@ -96,6 +96,37 @@ int spi_flash_read_common(struct spi_flash *flash, const u8 *cmd,
return ret;
}
+int spi_flash_cmd_rw_frame(struct spi_slave *spi, const u8 *cmd,
+ size_t cmd_len, void *data, size_t data_len)
+{
+ unsigned char *buffer;
+ int ret;
+
+ buffer = (unsigned char *)malloc(cmd_len + data_len);
+ if (!buffer) {
+ debug("SF: Failed to malloc memory.\n");
+ return 1;
+ }
+ if ( cmd_len&& cmd )
+ memcpy(buffer, cmd, cmd_len);
+ if ( data_len&& data )
+ memcpy(buffer+cmd_len, data, data_len);
+ ret = spi_xfer(spi, (cmd_len + data_len)*8, buffer, buffer,
+ SPI_XFER_BEGIN|SPI_XFER_END);
+ if (!ret) {
+ if ( cmd&& cmd_len )
+ memcpy(cmd, buffer,cmd_len);
+ if ( data&& data_len)
+ memcpy(data, buffer + cmd_len,data_len);
+ } else {
+ debug("SF: Transaction failed (command length: %zu bytes),"
+ " (data length: %zu bytes) : %d\n",
+ cmd_len, data_len, ret);
+ }
+ free(buffer);
+ return ret;
+}
+
struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
unsigned int max_hz, unsigned int spi_mode)
{
@@ -117,7 +148,8 @@ struct spi_flash *spi_flash_probe(unsigned int bus, unsigned int cs,
}
/* Read the ID codes */
- ret = spi_flash_cmd(spi, CMD_READ_ID,&idcode, sizeof(idcode));
+ idcode[0] = CMD_READ_ID;
+ ret = spi_flash_cmd_rw_frame(spi,&(idcode[0]), 1, idcode, sizeof(idcode));
if (ret)
goto err_read_id;
diff --git a/drivers/mtd/spi/spi_flash_internal.h b/drivers/mtd/spi/spi_flash_internal.h
old mode 100644
new mode 100755
index 08546fb..0455dcc
--- a/drivers/mtd/spi/spi_flash_internal.h
+++ b/drivers/mtd/spi/spi_flash_internal.h
@@ -43,6 +43,15 @@ int spi_flash_cmd_write(struct spi_slave *spi, const u8 *cmd, size_t cmd_len,
int spi_flash_read_common(struct spi_flash *flash, const u8 *cmd,
size_t cmd_len, void *data, size_t data_len);
+/*
+ * Similar to spi_flash_read_common() but command and data are combined and
+ * transferred in a single,pre-buffered frame. Useful for when the
+ * hardware makes it impossible to deterministically maintain CS state between
+ * disparate command and data calls.
+ */
+int spi_flash_cmd_rw_frame(struct spi_slave *spi, const u8 *cmd,
+ size_t cmd_len, void *data, size_t data_len);
+
/* Manufacturer-specific probe functions */
struct spi_flash *spi_flash_probe_spansion(struct spi_slave *spi, u8 *idcode);
struct spi_flash *spi_flash_probe_atmel(struct spi_slave *spi, u8 *idcode);
--
1.7.0.4
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