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path: root/drivers/tty/serial/8250/8250_port.c
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Diffstat (limited to 'drivers/tty/serial/8250/8250_port.c')
-rw-r--r--drivers/tty/serial/8250/8250_port.c36
1 files changed, 35 insertions, 1 deletions
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 1328c7e70108..95833cbc4338 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -47,6 +47,10 @@
#define UART_EXAR_SLEEP 0x8b /* Sleep mode */
#define UART_EXAR_DVID 0x8d /* Device identification */
+/* Nuvoton NPCM timeout register */
+#define UART_NPCM_TOR 7
+#define UART_NPCM_TOIE BIT(7) /* Timeout Interrupt Enable */
+
/*
* Debugging.
*/
@@ -293,6 +297,15 @@ static const struct serial8250_config uart_config[] = {
UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
.flags = UART_CAP_FIFO,
},
+ [PORT_NPCM] = {
+ .name = "Nuvoton 16550",
+ .fifo_size = 16,
+ .tx_loadsz = 16,
+ .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_10 |
+ UART_FCR_CLEAR_RCVR | UART_FCR_CLEAR_XMIT,
+ .rxtrig_bytes = {1, 4, 8, 14},
+ .flags = UART_CAP_FIFO,
+ },
};
/* Uart divisor latch read */
@@ -1854,7 +1867,8 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
status = serial_port_in(port, UART_LSR);
- if (status & (UART_LSR_DR | UART_LSR_BI)) {
+ if (status & (UART_LSR_DR | UART_LSR_BI) &&
+ iir & UART_IIR_RDI) {
if (!up->dma || handle_rx_dma(up, iir))
status = serial8250_rx_chars(up, status);
}
@@ -2140,6 +2154,15 @@ int serial8250_do_startup(struct uart_port *port)
UART_DA830_PWREMU_MGMT_FREE);
}
+ if (port->type == PORT_NPCM) {
+ /*
+ * Nuvoton calls the scratch register 'UART_TOR' (timeout
+ * register). Enable it, and set TIOC (timeout interrupt
+ * comparator) to be 0x20 for correct operation.
+ */
+ serial_port_out(port, UART_NPCM_TOR, UART_NPCM_TOIE | 0x20);
+ }
+
#ifdef CONFIG_SERIAL_8250_RSA
/*
* If this is an RSA port, see if we can kick it up to the
@@ -2462,6 +2485,15 @@ static unsigned int xr17v35x_get_divisor(struct uart_8250_port *up,
return quot_16 >> 4;
}
+/* Nuvoton NPCM UARTs have a custom divisor calculation */
+static unsigned int npcm_get_divisor(struct uart_8250_port *up,
+ unsigned int baud)
+{
+ struct uart_port *port = &up->port;
+
+ return DIV_ROUND_CLOSEST(port->uartclk, 16 * baud + 2) - 2;
+}
+
static unsigned int serial8250_get_divisor(struct uart_8250_port *up,
unsigned int baud,
unsigned int *frac)
@@ -2482,6 +2514,8 @@ static unsigned int serial8250_get_divisor(struct uart_8250_port *up,
quot = 0x8002;
else if (up->port.type == PORT_XR17V35X)
quot = xr17v35x_get_divisor(up, baud, frac);
+ else if (up->port.type == PORT_NPCM)
+ quot = npcm_get_divisor(up, baud);
else
quot = uart_get_divisor(port, baud);