This patch adds the possibility to (optinally) write to the
flash configuration register. The Intel style CFI chips support
such a register that can be used to configure the operation
mode to a non-default value.
This method will be used by the t3corp board, which needs to
configure the DS617 Xilinx flash for async read mode.
Signed-off-by: Stefan Roese <s...@denx.de>
---
drivers/mtd/cfi_flash.c | 43 +++++++++++++++++++++++++++++++++++++++++++
include/mtd/cfi_flash.h | 2 ++
2 files changed, 45 insertions(+), 0 deletions(-)
diff --git a/drivers/mtd/cfi_flash.c b/drivers/mtd/cfi_flash.c
index c17c542..6e617f0 100644
--- a/drivers/mtd/cfi_flash.c
+++ b/drivers/mtd/cfi_flash.c
@@ -74,6 +74,20 @@ flash_info_t flash_info[CFI_MAX_FLASH_BANKS]; /*
FLASH chips info */
#define CONFIG_SYS_FLASH_CFI_WIDTH FLASH_CFI_8BIT
#endif
+/*
+ * 0xffff is an undefined value for the configuration register. When
+ * this value is returned, the configuration register shall not be
+ * written at all (default mode).
+ */
+static u16 cfi_flash_config_reg(int i)
+{
+#ifdef CONFIG_SYS_CFI_FLASH_CONFIG_REGS
+ return ((u16 [])CONFIG_SYS_CFI_FLASH_CONFIG_REGS)[i];
+#else
+ return 0xffff;
+#endif
+}
+
#if defined(CONFIG_SYS_MAX_FLASH_BANKS_DETECT)
int cfi_flash_num_flash_banks = CONFIG_SYS_MAX_FLASH_BANKS_DETECT;
#endif
@@ -2031,6 +2045,31 @@ void flash_set_verbose(uint v)
flash_verbose = v;
}
+static void cfi_flash_set_config_reg(u32 base, u16 val)
+{
+#ifdef CONFIG_SYS_CFI_FLASH_CONFIG_REGS
+ /*
+ * Only set this config register if really defined
+ * to a valid value (0xffff is invalid)
+ */
+ if (val == 0xffff)
+ return;
+
+ /*
+ * Set configuration register. Data is "encrypted" in the 16 lower
+ * address bits.
+ */
+ flash_write16(FLASH_CMD_SETUP, (void *)(base + (val << 1)));
+ flash_write16(FLASH_CMD_SET_CR_CONFIRM, (void *)(base + (val << 1)));
+
+ /*
+ * Finally issue reset-command to bring device back to
+ * read-array mode
+ */
+ flash_write16(FLASH_CMD_RESET, (void *)base);
+#endif
+}
+
/*-----------------------------------------------------------------------
*/
unsigned long flash_init (void)
@@ -2054,6 +2093,10 @@ unsigned long flash_init (void)
for (i = 0; i < CONFIG_SYS_MAX_FLASH_BANKS; ++i) {
flash_info[i].flash_id = FLASH_UNKNOWN;
+ /* Optionally write flash configuration register */
+ cfi_flash_set_config_reg(cfi_flash_bank_addr(i),
+ cfi_flash_config_reg(i));
+
if (!flash_detect_legacy(cfi_flash_bank_addr(i), i))
flash_get_size(cfi_flash_bank_addr(i), i,
cfi_flash_bank_size(i));
diff --git a/include/mtd/cfi_flash.h b/include/mtd/cfi_flash.h
index 2ff00f2..3245b44 100644
--- a/include/mtd/cfi_flash.h
+++ b/include/mtd/cfi_flash.h
@@ -32,6 +32,8 @@
#define FLASH_CMD_ERASE_CONFIRM 0xD0
#define FLASH_CMD_WRITE 0x40
#define FLASH_CMD_PROTECT 0x60
+#define FLASH_CMD_SETUP 0x60
+#define FLASH_CMD_SET_CR_CONFIRM 0x03
#define FLASH_CMD_PROTECT_SET 0x01
#define FLASH_CMD_PROTECT_CLEAR 0xD0
#define FLASH_CMD_CLEAR_STATUS 0x50
--
1.7.3.2
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