From: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx> [ Upstream commit 6f81fdded0d024c7d4084d434764f30bca1cd6b1 ] Set the FEATURE_SEL at probe time to make sure that BIT(0) is enabled: this guarantees that when the port is configured as AP UART, the right register layout is interpreted by the UART IP. Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20220427132328.228297-3-angelogioacchino.delregno@xxxxxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/tty/serial/8250/8250_mtk.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c index de48a58460f4..de57f47635cd 100644 --- a/drivers/tty/serial/8250/8250_mtk.c +++ b/drivers/tty/serial/8250/8250_mtk.c @@ -57,6 +57,9 @@ #define MTK_UART_XON1 40 /* I/O: Xon character 1 */ #define MTK_UART_XOFF1 42 /* I/O: Xoff character 1 */ +#define MTK_UART_FEATURE_SEL 39 /* Feature Selection register */ +#define MTK_UART_FEAT_NEWRMAP BIT(0) /* Use new register map */ + #ifdef CONFIG_SERIAL_8250_DMA enum dma_rx_status { DMA_RX_START = 0, @@ -572,6 +575,10 @@ static int mtk8250_probe(struct platform_device *pdev) uart.dma = data->dma; #endif + /* Set AP UART new register map */ + writel(MTK_UART_FEAT_NEWRMAP, uart.port.membase + + (MTK_UART_FEATURE_SEL << uart.port.regshift)); + /* Disable Rate Fix function */ writel(0x0, uart.port.membase + (MTK_UART_RATE_FIX << uart.port.regshift)); -- 2.35.1
