On 30/6/26 15:57, Bin Meng wrote:
Macronix flashes expose DC[1:0] bits in the volatile configuration
register [1]. These bits select the number of dummy clock cycles
used by the fast-read command families.
Convert the Macronix dummy-cycle settings through per-command-family
tables and round up the non-byte-aligned cases that the byte-oriented
SSI model cannot represent exactly.
[1]
https://www.macronix.com/Lists/Datasheet/Attachments/8657/MX66L51235F,%203V,%20512Mb,%20v1.1.pdf
Fixes: cf6f1efe0b57 ("m25p80: Fast read commands family changes")
Signed-off-by: Bin Meng <[email protected]>
---
hw/block/m25p80.c | 66 +++++++++++++++++++++++++++--------------------
1 file changed, 38 insertions(+), 28 deletions(-)
+static uint8_t macronix_extract_cfg_num_dummies(Flash *s, uint8_t bus_width)
+{
+ static const uint8_t dummy_cycles_fast[4] = { 8, 6, 8, 10 };
+ static const uint8_t dummy_cycles_dio[4] = { 4, 6, 8, 10 };
+ static const uint8_t dummy_cycles_qio[4] = { 6, 4, 8, 10 };
+ const uint8_t *dummy_cycles = dummy_cycles_fast;
+ uint8_t num_dummies;
+
+ assert(get_man(s) == MAN_MACRONIX);
+
+ switch (s->cmd_in_progress) {
+ case DIOR:
+ case DIOR4:
+ dummy_cycles = dummy_cycles_dio;
+ break;
+ case QIOR:
+ case QIOR4:
+ dummy_cycles = dummy_cycles_qio;
+ break;
+ default:
+ break;
+ }
+
+ num_dummies = dummy_cycles[extract32(s->volatile_cfg, 6, 2)];
+ num_dummies *= bus_width;
+
+ if (num_dummies % 8) {
+ qemu_log_mask(LOG_UNIMP,
+ "M25P80: the number of dummy bits is not multiple of 8");
+ num_dummies = ROUND_UP(num_dummies, 8);
This is a programming error, I'd rather abort here and not
let the guest continue.
Otherwise:
Reviewed-by: Philippe Mathieu-Daudé <[email protected]>
+ }
+
+ return num_dummies / 8;
+}
