serial: 8250: Add IIR FIFOs enabled field properly

Don't use magic literals & comments but define a real field instead
for UART_IIR_FIFO_ENABLED and name also the values.

Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20221125130509.8482-5-ilpo.jarvinen@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ilpo Järvinen 2022-11-25 15:05:07 +02:00 committed by Greg Kroah-Hartman
parent 67a9aee781
commit 3398cc4f2b
2 changed files with 11 additions and 10 deletions

View file

@ -1293,22 +1293,19 @@ static void autoconfig(struct uart_8250_port *up)
serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO);
/* Assign this as it is to truncate any bits above 7. */
scratch = serial_in(up, UART_IIR);
switch (scratch >> 6) {
case 0:
switch (serial_in(up, UART_IIR) & UART_IIR_FIFO_ENABLED) {
case UART_IIR_FIFO_ENABLED_8250:
autoconfig_8250(up);
break;
case 1:
port->type = PORT_UNKNOWN;
break;
case 2:
case UART_IIR_FIFO_ENABLED_16550:
port->type = PORT_16550;
break;
case 3:
case UART_IIR_FIFO_ENABLED_16550A:
autoconfig_16550a(up);
break;
default:
port->type = PORT_UNKNOWN;
break;
}
#ifdef CONFIG_SERIAL_8250_RSA

View file

@ -44,6 +44,10 @@
#define UART_IIR_RX_TIMEOUT 0x0c /* OMAP RX Timeout interrupt */
#define UART_IIR_XOFF 0x10 /* OMAP XOFF/Special Character */
#define UART_IIR_CTS_RTS_DSR 0x20 /* OMAP CTS/RTS/DSR Change */
#define UART_IIR_FIFO_ENABLED 0xc0 /* FIFOs enabled / port type identification */
#define UART_IIR_FIFO_ENABLED_8250 0x00 /* 8250: no FIFO */
#define UART_IIR_FIFO_ENABLED_16550 0x80 /* 16550: (broken/unusable) FIFO */
#define UART_IIR_FIFO_ENABLED_16550A 0xc0 /* 16550A: FIFO enabled */
#define UART_FCR 2 /* Out: FIFO Control Register */
#define UART_FCR_ENABLE_FIFO 0x01 /* Enable the FIFO */