From a752cdd96f470f62fa0e8d8c2623ab6c146b2612 Mon Sep 17 00:00:00 2001 From: Justin Chen Date: Mon, 21 Aug 2023 11:52:51 -0700 Subject: [PATCH] BACKPORT: serial: 8250_bcm7271: improve bcm7271 8250 port The 8250 BCM7271 UART is not a direct match to PORT_16550A and other generic ports do not match its hardware capabilities. PORT_ALTR matches the rx trigger levels, but its vendor configurations are not compatible. Unfortunately this means we need to create another port to fully capture the hardware capabilities of the BCM7271 UART. To alleviate some latency pressures, we default the rx trigger level to 8. Bug: 365149220 Change-Id: I41005a210439a3a54a9af16a96583662dc8d786d Signed-off-by: Justin Chen Reviewed-by: Florian Fainelli Acked-by: Doug Berger Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/1692643978-16570-1-git-send-email-justin.chen@broadcom.com Signed-off-by: Greg Kroah-Hartman (cherry picked from commit 42a569cd0d774fd575395a84481f87a1aaa530df) Signed-off-by: Danesh Petigara --- 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 a28f115f6194..e011510737d7 100644 --- a/drivers/tty/serial/8250/8250_bcm7271.c +++ b/drivers/tty/serial/8250/8250_bcm7271.c @@ -1059,7 +1059,7 @@ 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; @@ -1073,8 +1073,6 @@ 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 1dc64a3401cc..d4b962676308 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -314,6 +314,14 @@ static const struct serial8250_config uart_config[] = { .rxtrig_bytes = {1, 4, 8, 14}, .flags = UART_CAP_FIFO, }, + [PORT_BCM7271] = { + .name = "Broadcom 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 3ba34d8378bd..1138d9bf7b18 100644 --- a/include/uapi/linux/serial_core.h +++ b/include/uapi/linux/serial_core.h @@ -144,6 +144,9 @@ /* Blackfin bf5xx */ #define PORT_BFIN 75 +/* Broadcom BCM7271 UART */ +#define PORT_BCM7271 76 + /* Broadcom SB1250, etc. SOC */ #define PORT_SB1250_DUART 77