From: Philippe Mathieu-Daudé <[email protected]>
When the block is disabled, it stay it is 'internal reset logic'
(internal clocks are gated off). Reading any register returns
its reset value. Only update this value if the device is enabled.
Ref: i.MX 6DQ Applications Processor Reference Manual (IMX6DQRM),
chapter 21.7.3: Control Register (ECSPIx_CONREG)
Reviewed-by: Juan Quintela <[email protected]>
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Message-Id: <[email protected]>
Reviewed-by: Bin Meng <[email protected]>
Signed-off-by: Bin Meng <[email protected]>
---
(no changes since v7)
Changes in v7:
- remove the RFC tag
Changes in v6:
- new patch: [RFC] rework imx_spi_read() to handle block disabled
hw/ssi/imx_spi.c | 60 +++++++++++++++++++++++++++-----------------------------
1 file changed, 29 insertions(+), 31 deletions(-)
diff --git a/hw/ssi/imx_spi.c b/hw/ssi/imx_spi.c
index c952a3d..277b936 100644
--- a/hw/ssi/imx_spi.c
+++ b/hw/ssi/imx_spi.c
@@ -274,42 +274,40 @@ static uint64_t imx_spi_read(void *opaque, hwaddr offset,
unsigned size)
return 0;
}
- switch (index) {
- case ECSPI_RXDATA:
- if (!imx_spi_is_enabled(s)) {
- value = 0;
- } else if (fifo32_is_empty(&s->rx_fifo)) {
- /* value is undefined */
- value = 0xdeadbeef;
- } else {
- /* read from the RX FIFO */
- value = fifo32_pop(&s->rx_fifo);
- }
-
- break;
- case ECSPI_TXDATA:
- qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Trying to read from TX FIFO\n",
- TYPE_IMX_SPI, __func__);
-
- /* Reading from TXDATA gives 0 */
-
- break;
- case ECSPI_MSGDATA:
- qemu_log_mask(LOG_GUEST_ERROR, "[%s]%s: Trying to read from MSG
FIFO\n",
- TYPE_IMX_SPI, __func__);
+ value = s->regs[index];
+
+ if (imx_spi_is_enabled(s)) {
+ switch (index) {
+ case ECSPI_RXDATA:
+ if (fifo32_is_empty(&s->rx_fifo)) {
+ /* value is undefined */
+ value = 0xdeadbeef;
+ } else {
+ /* read from the RX FIFO */
+ value = fifo32_pop(&s->rx_fifo);
+ }
+ break;
+ case ECSPI_TXDATA:
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "[%s]%s: Trying to read from TX FIFO\n",
+ TYPE_IMX_SPI, __func__);
- /* Reading from MSGDATA gives 0 */
+ /* Reading from TXDATA gives 0 */
+ break;
+ case ECSPI_MSGDATA:
+ qemu_log_mask(LOG_GUEST_ERROR,
+ "[%s]%s: Trying to read from MSG FIFO\n",
+ TYPE_IMX_SPI, __func__);
+ /* Reading from MSGDATA gives 0 */
+ break;
+ default:
+ break;
+ }
- break;
- default:
- value = s->regs[index];
- break;
+ imx_spi_update_irq(s);
}
-
DPRINTF("reg[%s] => 0x%" PRIx32 "\n", imx_spi_reg_name(index), value);
- imx_spi_update_irq(s);
-
return (uint64_t)value;
}
--
2.7.4
