diff options
Diffstat (limited to 'hw/ssi/aspeed_smc.c')
| -rw-r--r-- | hw/ssi/aspeed_smc.c | 64 |
1 files changed, 63 insertions, 1 deletions
diff --git a/hw/ssi/aspeed_smc.c b/hw/ssi/aspeed_smc.c index c1a45c10dc..7a0cd7607f 100644 --- a/hw/ssi/aspeed_smc.c +++ b/hw/ssi/aspeed_smc.c @@ -77,6 +77,10 @@ #define CTRL_CMD_MASK 0xff #define CTRL_DUMMY_HIGH_SHIFT 14 #define CTRL_AST2400_SPI_4BYTE (1 << 13) +#define CE_CTRL_CLOCK_FREQ_SHIFT 8 +#define CE_CTRL_CLOCK_FREQ_MASK 0xf +#define CE_CTRL_CLOCK_FREQ(div) \ + (((div) & CE_CTRL_CLOCK_FREQ_MASK) << CE_CTRL_CLOCK_FREQ_SHIFT) #define CTRL_DUMMY_LOW_SHIFT 6 /* 2 bits [7:6] */ #define CTRL_CE_STOP_ACTIVE (1 << 2) #define CTRL_CMD_MODE_MASK 0x3 @@ -112,7 +116,7 @@ #define DMA_CTRL_DELAY_SHIFT 8 #define DMA_CTRL_FREQ_MASK 0xf #define DMA_CTRL_FREQ_SHIFT 4 -#define DMA_CTRL_MODE (1 << 3) +#define DMA_CTRL_CALIB (1 << 3) #define DMA_CTRL_CKSUM (1 << 2) #define DMA_CTRL_WRITE (1 << 1) #define DMA_CTRL_ENABLE (1 << 0) @@ -811,6 +815,60 @@ static uint64_t aspeed_smc_read(void *opaque, hwaddr addr, unsigned int size) } } +static uint8_t aspeed_smc_hclk_divisor(uint8_t hclk_mask) +{ + /* HCLK/1 .. HCLK/16 */ + const uint8_t hclk_divisors[] = { + 15, 7, 14, 6, 13, 5, 12, 4, 11, 3, 10, 2, 9, 1, 8, 0 + }; + int i; + + for (i = 0; i < ARRAY_SIZE(hclk_divisors); i++) { + if (hclk_mask == hclk_divisors[i]) { + return i + 1; + } + } + + qemu_log_mask(LOG_GUEST_ERROR, "invalid HCLK mask %x", hclk_mask); + return 0; +} + +/* + * When doing calibration, the SPI clock rate in the CE0 Control + * Register and the read delay cycles in the Read Timing Compensation + * Register are set using bit[11:4] of the DMA Control Register. + */ +static void aspeed_smc_dma_calibration(AspeedSMCState *s) +{ + uint8_t delay = + (s->regs[R_DMA_CTRL] >> DMA_CTRL_DELAY_SHIFT) & DMA_CTRL_DELAY_MASK; + uint8_t hclk_mask = + (s->regs[R_DMA_CTRL] >> DMA_CTRL_FREQ_SHIFT) & DMA_CTRL_FREQ_MASK; + uint8_t hclk_div = aspeed_smc_hclk_divisor(hclk_mask); + uint32_t hclk_shift = (hclk_div - 1) << 2; + uint8_t cs; + + /* + * The Read Timing Compensation Register values apply to all CS on + * the SPI bus and only HCLK/1 - HCLK/5 can have tunable delays + */ + if (hclk_div && hclk_div < 6) { + s->regs[s->r_timings] &= ~(0xf << hclk_shift); + s->regs[s->r_timings] |= delay << hclk_shift; + } + + /* + * TODO: compute the CS from the DMA address and the segment + * registers. This is not really a problem for now because the + * Timing Register values apply to all CS and software uses CS0 to + * do calibration. + */ + cs = 0; + s->regs[s->r_ctrl0 + cs] &= + ~(CE_CTRL_CLOCK_FREQ_MASK << CE_CTRL_CLOCK_FREQ_SHIFT); + s->regs[s->r_ctrl0 + cs] |= CE_CTRL_CLOCK_FREQ(hclk_div); +} + /* * Accumulate the result of the reads to provide a checksum that will * be used to validate the read timing settings. @@ -826,6 +884,10 @@ static void aspeed_smc_dma_checksum(AspeedSMCState *s) return; } + if (s->regs[R_DMA_CTRL] & DMA_CTRL_CALIB) { + aspeed_smc_dma_calibration(s); + } + while (s->regs[R_DMA_LEN]) { data = address_space_ldl_le(&s->flash_as, s->regs[R_DMA_FLASH_ADDR], MEMTXATTRS_UNSPECIFIED, &result); |