[U-Boot] [PATCH 15/18] sf: prepare next fixes to support of QSPI memories by manufacturer
Cyrille Pitchen
cyrille.pitchen at atmel.com
Tue Mar 15 19:12:37 CET 2016
This is just a transitional patch to add manufacturer dedicated support
for QSPI memories.
Indeed, using Quad SPI protocols is slighty more complicated than simply
enabling the Quad I/O or QPI mode. We should also take care about the
number of dummy cycles. For instance, some Spansion QSPI memories use a
factory default value of 6 dummy cycles.
Besides we have to care about the mode cycles: special kind of dummy
cycles which make the SPI flash memory enter/leaver its Continuous Read/
Enhanced Performance mode. This mode is actually used by XIP operations
but not relevant in the MTD layer. However we should prevent the SPI flash
memory from entering Continuous Read mode by mistake.
Depending on the manufacturer, it can be done by using the right Fast Read
op code (Winbond) or by updating a dedicated bit in one configuration
register (Micron).
Also the QSPI manufacturers don't support the exact same SPI protocols for
Fast Read operations. We need to provide a mean to tune SPI protocols and
the op codes by manufacturer.
For all these reasons, future patches are to come to add QSPI support by
manufacturer. Till then, the legacy code is still used as a fallback
implementation.
Signed-off-by: Cyrille Pitchen <cyrille.pitchen at atmel.com>
---
drivers/mtd/spi/spi_flash.c | 155 ++++++++++++++++++++++++++++----------------
1 file changed, 99 insertions(+), 56 deletions(-)
diff --git a/drivers/mtd/spi/spi_flash.c b/drivers/mtd/spi/spi_flash.c
index b4a44e25f190..50250491d228 100644
--- a/drivers/mtd/spi/spi_flash.c
+++ b/drivers/mtd/spi/spi_flash.c
@@ -1033,6 +1033,98 @@ static int set_quad_mode(struct spi_flash *flash, u8 idcode0)
}
}
+/* Transitional function to be removed */
+static int spi_flash_setup_deprecated(struct spi_flash *flash,
+ const struct spi_flash_params *params,
+ int best_match)
+{
+ struct spi_slave *spi = flash->spi;
+ u8 idcode0 = params->jedec >> 16;
+ u8 cmd;
+ int ret;
+ static u8 spi_read_cmds_array[] = {
+ CMD_READ_ARRAY_SLOW,
+ CMD_READ_ARRAY_FAST,
+ CMD_READ_DUAL_OUTPUT_FAST,
+ CMD_READ_QUAD_OUTPUT_FAST,
+ CMD_READ_DUAL_IO_FAST,
+ CMD_READ_QUAD_IO_FAST,
+ CMD_READ_DUAL_IO_FAST, /* same op code as for DUAL_IO_FAST */
+ CMD_READ_QUAD_IO_FAST, /* same op code as for QUAD_IO_FAST */
+ };
+
+ /* Look for the fastest read cmd */
+ if (best_match) {
+ cmd = spi_read_cmds_array[best_match - 1];
+ flash->read_cmd = cmd;
+ } else {
+ /* Go for default supported read cmd */
+ flash->read_cmd = CMD_READ_ARRAY_FAST;
+ }
+
+ /* Not require to look for fastest only two write cmds yet */
+ if (params->flags & WR_QPP && spi->mode & SPI_TX_QUAD)
+ flash->write_cmd = CMD_QUAD_PAGE_PROGRAM;
+ else
+ /* Go for default supported write cmd */
+ flash->write_cmd = CMD_PAGE_PROGRAM;
+
+ /* Set the quad enable bit - only for quad commands */
+ if ((flash->read_cmd == CMD_READ_QUAD_OUTPUT_FAST) ||
+ (flash->read_cmd == CMD_READ_QUAD_IO_FAST) ||
+ (flash->write_cmd == CMD_QUAD_PAGE_PROGRAM)) {
+ ret = set_quad_mode(flash, idcode0);
+ if (ret) {
+ debug("SF: Fail to set QEB for %02x\n", idcode0);
+ return -EINVAL;
+ }
+ }
+
+ /* Read dummy_byte: dummy byte is determined based on the
+ * dummy cycles of a particular command.
+ * Fast commands - dummy_byte = dummy_cycles/8
+ * I/O commands- dummy_byte = (dummy_cycles * no.of lines)/8
+ * For I/O commands except cmd[0] everything goes on no.of lines
+ * based on particular command but incase of fast commands except
+ * data all go on single line irrespective of command.
+ */
+ switch (flash->read_cmd) {
+ case CMD_READ_QUAD_IO_FAST:
+ flash->dummy_byte = 2;
+ break;
+ case CMD_READ_ARRAY_SLOW:
+ flash->dummy_byte = 0;
+ break;
+ default:
+ flash->dummy_byte = 1;
+ }
+
+ return 0;
+}
+
+static int spi_flash_setup(struct spi_flash *flash,
+ const struct spi_flash_params *params,
+ u8 e_rd_cmd)
+{
+ int match = fls(params->e_rd_cmd & e_rd_cmd);
+
+ /*
+ * The (Fast) Read and Page Program opcodes to be used depends on the
+ * manufacturer.
+ */
+ switch (params->jedec >> 16) {
+ /*
+ * TODO: Manufacturer dedicated setup will be added HERE by
+ * further patches.
+ */
+
+ default:
+ return spi_flash_setup_deprecated(flash, params, match);
+ }
+
+ return 0;
+}
+
#if CONFIG_IS_ENABLED(OF_CONTROL)
int spi_flash_decode_fdt(const void *blob, struct spi_flash *flash)
{
@@ -1090,18 +1182,8 @@ int spi_flash_scan(struct spi_flash *flash, u8 e_rd_cmd)
const struct spi_flash_params *params;
const struct spi_flash_read_id_config *cfg;
u16 jedec, ext_jedec;
- u8 cmd, idcode[5];
+ u8 idcode[5];
int ret;
- static u8 spi_read_cmds_array[] = {
- CMD_READ_ARRAY_SLOW,
- CMD_READ_ARRAY_FAST,
- CMD_READ_DUAL_OUTPUT_FAST,
- CMD_READ_QUAD_OUTPUT_FAST,
- CMD_READ_DUAL_IO_FAST,
- CMD_READ_QUAD_IO_FAST,
- CMD_READ_DUAL_IO_FAST, /* same op code as for DUAL_IO_FAST */
- CMD_READ_QUAD_IO_FAST, /* same op code as for QUAD_IO_FAST */
- };
/* Assign spi_flash ops */
#ifndef CONFIG_DM_SPI_FLASH
@@ -1238,52 +1320,13 @@ int spi_flash_scan(struct spi_flash *flash, u8 e_rd_cmd)
/* Now erase size becomes valid sector size */
flash->sector_size = flash->erase_size;
- /* Look for the fastest read cmd */
- cmd = fls(params->e_rd_cmd & e_rd_cmd);
- if (cmd) {
- cmd = spi_read_cmds_array[cmd - 1];
- flash->read_cmd = cmd;
- } else {
- /* Go for default supported read cmd */
- flash->read_cmd = CMD_READ_ARRAY_FAST;
- }
-
- /* Not require to look for fastest only two write cmds yet */
- if (params->flags & WR_QPP && spi->mode & SPI_TX_QUAD)
- flash->write_cmd = CMD_QUAD_PAGE_PROGRAM;
- else
- /* Go for default supported write cmd */
- flash->write_cmd = CMD_PAGE_PROGRAM;
-
- /* Set the quad enable bit - only for quad commands */
- if ((flash->read_cmd == CMD_READ_QUAD_OUTPUT_FAST) ||
- (flash->read_cmd == CMD_READ_QUAD_IO_FAST) ||
- (flash->write_cmd == CMD_QUAD_PAGE_PROGRAM)) {
- ret = set_quad_mode(flash, idcode[0]);
- if (ret) {
- debug("SF: Fail to set QEB for %02x\n", idcode[0]);
- return -EINVAL;
- }
- }
-
- /* Read dummy_byte: dummy byte is determined based on the
- * dummy cycles of a particular command.
- * Fast commands - dummy_byte = dummy_cycles/8
- * I/O commands- dummy_byte = (dummy_cycles * no.of lines)/8
- * For I/O commands except cmd[0] everything goes on no.of lines
- * based on particular command but incase of fast commands except
- * data all go on single line irrespective of command.
+ /*
+ * Setup (Fast) Read & Page Program opcode and protocols.
+ * Also set the right number of dummy/mode cycles.
*/
- switch (flash->read_cmd) {
- case CMD_READ_QUAD_IO_FAST:
- flash->dummy_byte = 2;
- break;
- case CMD_READ_ARRAY_SLOW:
- flash->dummy_byte = 0;
- break;
- default:
- flash->dummy_byte = 1;
- }
+ ret = spi_flash_setup(flash, params, e_rd_cmd);
+ if (ret < 0)
+ return ret;
#ifdef CONFIG_SPI_FLASH_STMICRO
if (params->flags & E_FSR)
--
1.8.2.2
More information about the U-Boot
mailing list