[PATCH] serial: 8250_bcm7271: improve bcm7271 8250 port

From: Justin Chen
Date: Fri Aug 11 2023 - 18:15:14 EST


The 8250 bcm7271 UART is not a direct match to PORT_16550A. The
Fifo is 32 and rxtrig values are {1, 8, 16, 30}. Create a PORT_BCM7271
to better capture the HW CAPS.

Default the rxtrig level to 8.

Signed-off-by: Justin Chen <justin.chen@xxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_bcm7271.c | 4 +---
drivers/tty/serial/8250/8250_port.c | 8 ++++++++
include/uapi/linux/serial_core.h | 3 +++
3 files changed, 12 insertions(+), 3 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_bcm7271.c b/drivers/tty/serial/8250/8250_bcm7271.c
index d4b05d7ad9e8..aa5aff046756 100644
--- a/drivers/tty/serial/8250/8250_bcm7271.c
+++ b/drivers/tty/serial/8250/8250_bcm7271.c
@@ -1042,7 +1042,7 @@ static int brcmuart_probe(struct platform_device *pdev)
dev_dbg(dev, "DMA is %senabled\n", priv->dma_enabled ? "" : "not ");

memset(&up, 0, sizeof(up));
- up.port.type = PORT_16550A;
+ up.port.type = PORT_BCM7271;
up.port.uartclk = clk_rate;
up.port.dev = dev;
up.port.mapbase = mapbase;
@@ -1056,8 +1056,6 @@ static int brcmuart_probe(struct platform_device *pdev)
| UPF_FIXED_PORT | UPF_FIXED_TYPE;
up.port.dev = dev;
up.port.private_data = priv;
- up.capabilities = UART_CAP_FIFO | UART_CAP_AFE;
- up.port.fifosize = 32;

/* Check for a fixed line number */
ret = of_alias_get_id(np, "serial");
diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c
index 16aeb1420137..a6259a264041 100644
--- a/drivers/tty/serial/8250/8250_port.c
+++ b/drivers/tty/serial/8250/8250_port.c
@@ -322,6 +322,14 @@ static const struct serial8250_config uart_config[] = {
.rxtrig_bytes = {2, 66, 130, 194},
.flags = UART_CAP_FIFO,
},
+ [PORT_BCM7271] = {
+ .name = "bcm7271_uart",
+ .fifo_size = 32,
+ .tx_loadsz = 32,
+ .fcr = UART_FCR_ENABLE_FIFO | UART_FCR_R_TRIG_01,
+ .rxtrig_bytes = {1, 8, 16, 30},
+ .flags = UART_CAP_FIFO | UART_CAP_AFE
+ },
};

/* Uart divisor latch read */
diff --git a/include/uapi/linux/serial_core.h b/include/uapi/linux/serial_core.h
index 281fa286555c..369f845a3d1d 100644
--- a/include/uapi/linux/serial_core.h
+++ b/include/uapi/linux/serial_core.h
@@ -279,4 +279,7 @@
/* Sunplus UART */
#define PORT_SUNPLUS 123

+/* Broadcom 7271 UART */
+#define PORT_BCM7271 124
+
#endif /* _UAPILINUX_SERIAL_CORE_H */
--
2.7.4

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