[PATCH v6 06/11] spi: aspeed: Workaround AST2500 limitations

From: Cédric Le Goater
Date: Tue May 03 2022 - 02:07:49 EST


It is not possible to configure a full 128MB window for a chip of the
same size on the AST2500 SPI controller. For this case, the maximum
window size is restricted to 120MB for CE0.

Reviewed-by: Joel Stanley <joel@xxxxxxxxx>
Tested-by: Joel Stanley <joel@xxxxxxxxx>
Tested-by: Tao Ren <rentao.bupt@xxxxxxxxx>
Tested-by: Jae Hyun Yoo <quic_jaehyoo@xxxxxxxxxxx>
Signed-off-by: Cédric Le Goater <clg@xxxxxxxx>
---
drivers/spi/spi-aspeed-smc.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/drivers/spi/spi-aspeed-smc.c b/drivers/spi/spi-aspeed-smc.c
index 0aff42e20b8d..d2b3342c133e 100644
--- a/drivers/spi/spi-aspeed-smc.c
+++ b/drivers/spi/spi-aspeed-smc.c
@@ -451,6 +451,8 @@ static int aspeed_spi_set_window(struct aspeed_spi *aspi,
* - ioremap each window, not strictly necessary since the overall window
* is correct.
*/
+static const struct aspeed_spi_data ast2500_spi_data;
+
static int aspeed_spi_chip_adjust_window(struct aspeed_spi_chip *chip,
u32 local_offset, u32 size)
{
@@ -459,6 +461,16 @@ static int aspeed_spi_chip_adjust_window(struct aspeed_spi_chip *chip,
struct aspeed_spi_window *win = &windows[chip->cs];
int ret;

+ /*
+ * Due to an HW issue on the AST2500 SPI controller, the CE0
+ * window size should be smaller than the maximum 128MB.
+ */
+ if (aspi->data == &ast2500_spi_data && chip->cs == 0 && size == SZ_128M) {
+ size = 120 << 20;
+ dev_info(aspi->dev, "CE%d window resized to %dMB (AST2500 HW quirk)",
+ chip->cs, size >> 20);
+ }
+
aspeed_spi_get_windows(aspi, windows);

/* Adjust this chip window */
--
2.35.1