From 7c87bb5333f0fdb17fee7e52acff1d915a68857e Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= Date: Fri, 29 Jan 2021 21:23:18 +0800 Subject: [PATCH] hw/ssi: imx_spi: Rework imx_spi_read() to handle block disabled MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Signed-off-by: Philippe Mathieu-Daudé Reviewed-by: Bin Meng Signed-off-by: Bin Meng Message-id: 20210129132323.30946-6-bmeng.cn@gmail.com Message-Id: <20210115153049.3353008-5-f4bug@amsat.org> Reviewed-by: Bin Meng Signed-off-by: Bin Meng Signed-off-by: Peter Maydell --- 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 e85be6ae60..21e2c9dea3 100644 --- a/hw/ssi/imx_spi.c +++ b/hw/ssi/imx_spi.c @@ -279,42 +279,40 @@ 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); + 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 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; - 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__); - - /* Reading from MSGDATA gives 0 */ - - 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; }