diff options
Diffstat (limited to 'hw/ssi/aspeed_smc.c')
| -rw-r--r-- | hw/ssi/aspeed_smc.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/hw/ssi/aspeed_smc.c b/hw/ssi/aspeed_smc.c index ae1ad2dba6..087b29e8da 100644 --- a/hw/ssi/aspeed_smc.c +++ b/hw/ssi/aspeed_smc.c @@ -69,7 +69,9 @@ #define R_CTRL0 (0x10 / 4) #define CTRL_CMD_SHIFT 16 #define CTRL_CMD_MASK 0xff +#define CTRL_DUMMY_HIGH_SHIFT 14 #define CTRL_AST2400_SPI_4BYTE (1 << 13) +#define CTRL_DUMMY_LOW_SHIFT 6 /* 2 bits [7:6] */ #define CTRL_CE_STOP_ACTIVE (1 << 2) #define CTRL_CMD_MODE_MASK 0x3 #define CTRL_READMODE 0x0 @@ -485,6 +487,16 @@ static uint32_t aspeed_smc_check_segment_addr(const AspeedSMCFlash *fl, return addr; } +static int aspeed_smc_flash_dummies(const AspeedSMCFlash *fl) +{ + const AspeedSMCState *s = fl->controller; + uint32_t r_ctrl0 = s->regs[s->r_ctrl0 + fl->id]; + uint32_t dummy_high = (r_ctrl0 >> CTRL_DUMMY_HIGH_SHIFT) & 0x1; + uint32_t dummy_low = (r_ctrl0 >> CTRL_DUMMY_LOW_SHIFT) & 0x3; + + return ((dummy_high << 2) | dummy_low) * 8; +} + static void aspeed_smc_flash_send_addr(AspeedSMCFlash *fl, uint32_t addr) { const AspeedSMCState *s = fl->controller; @@ -521,6 +533,15 @@ static uint64_t aspeed_smc_flash_read(void *opaque, hwaddr addr, unsigned size) aspeed_smc_flash_select(fl); aspeed_smc_flash_send_addr(fl, addr); + /* + * Use fake transfers to model dummy bytes. The value should + * be configured to some non-zero value in fast read mode and + * zero in read mode. + */ + for (i = 0; i < aspeed_smc_flash_dummies(fl); i++) { + ssi_transfer(fl->controller->spi, 0xFF); + } + for (i = 0; i < size; i++) { ret |= ssi_transfer(s->spi, 0x0) << (8 * i); } |