tty: 8250: Add 64byte UART support for FSL platforms

[firefly-linux-kernel-4.4.55.git] / drivers / tty / serial / 8250 / 8250_core.c

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 3bfcfdb57d052f0844aad743bd4c218e82738a07..689169c11f0fc4153ad2a5e45d840a1712440faf 100644 (file)
--- 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;