aspeed/smc: Add support for address lane disablement
The controller can be configured to disable or enable address and data
byte lanes when issuing commands. This is useful in read command mode
to send SPI NOR commands that don't have an address space, such as
RDID. It's a good way to have a unified read operation for registers
and flash contents accesses.
A new SPI driver proposed by Aspeed makes use of this feature. Add
support for address lanes to start with. We will do the same for the
data lanes if they are controlled one day.
Cc: Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Message-Id: <20201120161547.740806-2-clg@kaod.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
diff --git a/hw/ssi/aspeed_smc.c b/hw/ssi/aspeed_smc.c
index 795784e..e3d5e26 100644
--- a/hw/ssi/aspeed_smc.c
+++ b/hw/ssi/aspeed_smc.c
@@ -71,6 +71,16 @@
#define INTR_CTRL_CMD_ABORT_EN (1 << 2)
#define INTR_CTRL_WRITE_PROTECT_EN (1 << 1)
+/* Command Control Register */
+#define R_CE_CMD_CTRL (0x0C / 4)
+#define CTRL_ADDR_BYTE0_DISABLE_SHIFT 4
+#define CTRL_DATA_BYTE0_DISABLE_SHIFT 0
+
+#define aspeed_smc_addr_byte_enabled(s, i) \
+ (!((s)->regs[R_CE_CMD_CTRL] & (1 << (CTRL_ADDR_BYTE0_DISABLE_SHIFT + (i)))))
+#define aspeed_smc_data_byte_enabled(s, i) \
+ (!((s)->regs[R_CE_CMD_CTRL] & (1 << (CTRL_DATA_BYTE0_DISABLE_SHIFT + (i)))))
+
/* CEx Control Register */
#define R_CTRL0 (0x10 / 4)
#define CTRL_IO_QPI (1 << 31)
@@ -702,19 +712,17 @@
{
const AspeedSMCState *s = fl->controller;
uint8_t cmd = aspeed_smc_flash_cmd(fl);
- int i;
+ int i = aspeed_smc_flash_is_4byte(fl) ? 4 : 3;
/* Flash access can not exceed CS segment */
addr = aspeed_smc_check_segment_addr(fl, addr);
ssi_transfer(s->spi, cmd);
-
- if (aspeed_smc_flash_is_4byte(fl)) {
- ssi_transfer(s->spi, (addr >> 24) & 0xff);
+ while (i--) {
+ if (aspeed_smc_addr_byte_enabled(s, i)) {
+ ssi_transfer(s->spi, (addr >> (i * 8)) & 0xff);
+ }
}
- ssi_transfer(s->spi, (addr >> 16) & 0xff);
- ssi_transfer(s->spi, (addr >> 8) & 0xff);
- ssi_transfer(s->spi, (addr & 0xff));
/*
* Use fake transfers to model dummy bytes. The value should
@@ -988,6 +996,7 @@
(addr >= s->r_timings &&
addr < s->r_timings + s->ctrl->nregs_timings) ||
addr == s->r_ce_ctrl ||
+ addr == R_CE_CMD_CTRL ||
addr == R_INTR_CTRL ||
addr == R_DUMMY_DATA ||
(s->ctrl->has_dma && addr == R_DMA_CTRL) ||
@@ -1276,6 +1285,8 @@
if (value != s->regs[R_SEG_ADDR0 + cs]) {
aspeed_smc_flash_set_segment(s, cs, value);
}
+ } else if (addr == R_CE_CMD_CTRL) {
+ s->regs[addr] = value & 0xff;
} else if (addr == R_DUMMY_DATA) {
s->regs[addr] = value & 0xff;
} else if (addr == R_INTR_CTRL) {
