diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c index 3bfcfdb57d052..689169c11f0fc 100644 --- a/drivers/tty/serial/8250/8250_core.c +++ b/drivers/tty/serial/8250/8250_core.c @@ -329,6 +329,17 @@ static const struct serial8250_config uart_config[] = { .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10, .flags = UART_CAP_FIFO | UART_CAP_AFE, }, +/* tx_loadsz is set to 63-bytes instead of 64-bytes to implement +workaround of errata A-008006 which states that tx_loadsz should be +configured less than Maximum supported fifo bytes */ + [PORT_16550A_FSL64] = { + .name = "16550A_FSL64", + .fifo_size = 64, + .tx_loadsz = 63, + .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 | + UART_FCR7_64BYTE, + .flags = UART_CAP_FIFO, + }, }; /* Uart divisor latch read */ @@ -956,7 +967,17 @@ static void autoconfig_16550a(struct uart_8250_port *up) up->port.type = PORT_16650; up->capabilities |= UART_CAP_EFR | UART_CAP_SLEEP; } else { - DEBUG_AUTOCONF("Motorola 8xxx DUART "); + serial_out(up, UART_LCR, 0); + serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | + UART_FCR7_64BYTE); + status1 = serial_in(up, UART_IIR) >> 5; + serial_out(up, UART_FCR, 0); + serial_out(up, UART_LCR, 0); + + if (status1 == 7) + up->port.type = PORT_16550A_FSL64; + else + DEBUG_AUTOCONF("Motorola 8xxx DUART "); } serial_out(up, UART_EFR, 0); return; diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h index 9124e837c181c..ee628c489e47f 100644 --- a/include/uapi/linux/serial_core.h +++ b/include/uapi/linux/serial_core.h @@ -55,7 +55,8 @@ #define PORT_ALTR_16550_F64 27 /* Altera 16550 UART with 64 FIFOs */ #define PORT_ALTR_16550_F128 28 /* Altera 16550 UART with 128 FIFOs */ #define PORT_RT2880 29 /* Ralink RT2880 internal UART */ -#define PORT_MAX_8250 29 /* max port ID */ +#define PORT_16550A_FSL64 30 /* Freescale 16550 UART with 64 FIFOs */ +#define PORT_MAX_8250 30 /* max port ID */ /* * ARM specific type numbers. These are not currently guaranteed diff --git a/include/uapi/linux/serial_reg.h b/include/uapi/linux/serial_reg.h index 53af3b790129e..00adb01fa5f38 100644 --- a/include/uapi/linux/serial_reg.h +++ b/include/uapi/linux/serial_reg.h @@ -86,7 +86,8 @@ #define UART_FCR6_T_TRIGGER_8 0x10 /* Mask for transmit trigger set at 8 */ #define UART_FCR6_T_TRIGGER_24 0x20 /* Mask for transmit trigger set at 24 */ #define UART_FCR6_T_TRIGGER_30 0x30 /* Mask for transmit trigger set at 30 */ -#define UART_FCR7_64BYTE 0x20 /* Go into 64 byte mode (TI16C750) */ +#define UART_FCR7_64BYTE 0x20 /* Go into 64 byte mode (TI16C750 and + some Freescale UARTs) */ #define UART_FCR_R_TRIG_SHIFT 6 #define UART_FCR_R_TRIG_BITS(x) \