From 552114b8cbbd956ad8466261b5f11b059eba82ca Mon Sep 17 00:00:00 2001 From: Minda Chen Date: Sun, 25 Jun 2023 09:40:29 +0800 Subject: [PATCH 066/116] uart: 8250: Add dw auto flow ctrl support Add designeware 8250 auto flow ctrl support. Enable it by add auto-flow-control in dts. Signed-off-by: Minda Chen --- drivers/tty/serial/8250/8250_core.c | 2 ++ drivers/tty/serial/8250/8250_dw.c | 3 +++ drivers/tty/serial/8250/8250_port.c | 14 +++++++++++++- include/linux/serial_8250.h | 1 + include/uapi/linux/serial_core.h | 2 ++ 5 files changed, 21 insertions(+), 1 deletion(-) --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -1129,6 +1129,8 @@ int serial8250_register_8250_port(const uart->dl_read = up->dl_read; if (up->dl_write) uart->dl_write = up->dl_write; + if (up->probe) + uart->probe = up->probe; if (uart->port.type != PORT_8250_CIR) { if (serial8250_isa_config != NULL) --- a/drivers/tty/serial/8250/8250_dw.c +++ b/drivers/tty/serial/8250/8250_dw.c @@ -612,6 +612,9 @@ static int dw8250_probe(struct platform_ data->msr_mask_off |= UART_MSR_TERI; } + if (device_property_read_bool(dev, "auto-flow-control")) + up->probe |= UART_PROBE_AFE; + /* If there is separate baudclk, get the rate from it. */ data->clk = devm_clk_get_optional(dev, "baudclk"); if (data->clk == NULL) --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -330,6 +330,14 @@ static const struct serial8250_config ua .rxtrig_bytes = {1, 8, 16, 30}, .flags = UART_CAP_FIFO | UART_CAP_AFE, }, + [PORT_16550A_AFE] = { + .name = "16550A_AFE", + .fifo_size = 16, + .tx_loadsz = 16, + .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, + .rxtrig_bytes = {1, 4, 8, 14}, + .flags = UART_CAP_FIFO | UART_CAP_AFE, + }, }; /* Uart divisor latch read */ @@ -1143,6 +1151,11 @@ static void autoconfig_16550a(struct uar up->port.type = PORT_U6_16550A; up->capabilities |= UART_CAP_AFE; } + + if ((up->port.type == PORT_16550A) && (up->probe & UART_PROBE_AFE)) { + up->port.type = PORT_16550A_AFE; + up->capabilities |= UART_CAP_AFE; + } } /* @@ -2813,7 +2826,6 @@ serial8250_do_set_termios(struct uart_po if (termios->c_cflag & CRTSCTS) up->mcr |= UART_MCR_AFE; } - /* * Update the per-port timeout. */ --- a/include/linux/serial_8250.h +++ b/include/linux/serial_8250.h @@ -141,6 +141,7 @@ struct uart_8250_port { unsigned char probe; struct mctrl_gpios *gpios; #define UART_PROBE_RSA (1 << 0) +#define UART_PROBE_AFE (1 << 1) /* * Some bits in registers are cleared on a read, so they must --- a/include/uapi/linux/serial_core.h +++ b/include/uapi/linux/serial_core.h @@ -245,4 +245,6 @@ /* Sunplus UART */ #define PORT_SUNPLUS 123 +#define PORT_16550A_AFE 124 + #endif /* _UAPILINUX_SERIAL_CORE_H */