From 9fa3c4b1fa379f2b55859c6d27ba0563aac06516 Mon Sep 17 00:00:00 2001 From: Roja Rani Yarubandi Date: Wed, 4 Mar 2020 16:52:03 +0530 Subject: [PATCH] tty: serial: qcom_geni_serial: Fix GPIO swapping with workaround Add capability to support RX-TX, CTS-RTS pins swap in HW. Configure UART_IO_MACRO_CTRL register accordingly if RX-TX pair or CTS-RTS pair or both pairs swapped. Signed-off-by: Roja Rani Yarubandi Reviewed-by: Stephen Boyd Tested-by: Matthias Kaehlcke Reviewed-by: Matthias Kaehlcke Link: https://lore.kernel.org/r/20200304112203.408-1-rojay@codeaurora.org Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/qcom_geni_serial.c | 30 +++++++++++++++++++++++++++ 1 file changed, 30 insertions(+) diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 0bd1684cabb3..272bae0eebc7 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -21,6 +21,7 @@ /* UART specific GENI registers */ #define SE_UART_LOOPBACK_CFG 0x22c +#define SE_UART_IO_MACRO_CTRL 0x240 #define SE_UART_TX_TRANS_CFG 0x25c #define SE_UART_TX_WORD_LEN 0x268 #define SE_UART_TX_STOP_BIT_LEN 0x26c @@ -95,6 +96,12 @@ #define CTS_RTS_SORTED BIT(1) #define RX_TX_CTS_RTS_SORTED (RX_TX_SORTED | CTS_RTS_SORTED) +/* UART pin swap value */ +#define DEFAULT_IO_MACRO_IO0_IO1_MASK GENMASK(3, 0) +#define IO_MACRO_IO0_SEL 0x3 +#define DEFAULT_IO_MACRO_IO2_IO3_MASK GENMASK(15, 4) +#define IO_MACRO_IO2_IO3_SWAP 0x4640 + #ifdef CONFIG_CONSOLE_POLL #define CONSOLE_RX_BYTES_PW 1 #else @@ -119,6 +126,8 @@ struct qcom_geni_serial_port { unsigned int tx_remaining; int wakeup_irq; + bool rx_tx_swap; + bool cts_rts_swap; }; static const struct uart_ops qcom_geni_console_pops; @@ -836,6 +845,7 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport) struct qcom_geni_serial_port *port = to_dev_port(uport, uport); u32 rxstale = DEFAULT_BITS_PER_CHAR * STALE_TIMEOUT; u32 proto; + u32 pin_swap; if (uart_console(uport)) { port->tx_bytes_pw = 1; @@ -856,6 +866,20 @@ static int qcom_geni_serial_port_setup(struct uart_port *uport) get_tx_fifo_size(port); writel(rxstale, uport->membase + SE_UART_RX_STALE_CNT); + + pin_swap = readl(uport->membase + SE_UART_IO_MACRO_CTRL); + if (port->rx_tx_swap) { + pin_swap &= ~DEFAULT_IO_MACRO_IO2_IO3_MASK; + pin_swap |= IO_MACRO_IO2_IO3_SWAP; + } + if (port->cts_rts_swap) { + pin_swap &= ~DEFAULT_IO_MACRO_IO0_IO1_MASK; + pin_swap |= IO_MACRO_IO0_SEL; + } + /* Configure this register if RX-TX, CTS-RTS pins are swapped */ + if (port->rx_tx_swap || port->cts_rts_swap) + writel(pin_swap, uport->membase + SE_UART_IO_MACRO_CTRL); + /* * Make an unconditional cancel on the main sequencer to reset * it else we could end up in data loss scenarios. @@ -1299,6 +1323,12 @@ static int qcom_geni_serial_probe(struct platform_device *pdev) if (!console) port->wakeup_irq = platform_get_irq_optional(pdev, 1); + if (of_property_read_bool(pdev->dev.of_node, "rx-tx-swap")) + port->rx_tx_swap = true; + + if (of_property_read_bool(pdev->dev.of_node, "cts-rts-swap")) + port->cts_rts_swap = true; + uport->private_data = drv; platform_set_drvdata(pdev, port); port->handle_rx = console ? handle_rx_console : handle_rx_uart;