From 1543e317f1da31b75942316931e8f491a8920811 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Thu, 04 Jan 2024 10:08:02 +0000
Subject: [PATCH] disable FB
---
kernel/drivers/tty/serial/ar933x_uart.c | 122 ++++++++++++++++++++++++++++++++++++++--
1 files changed, 116 insertions(+), 6 deletions(-)
diff --git a/kernel/drivers/tty/serial/ar933x_uart.c b/kernel/drivers/tty/serial/ar933x_uart.c
index ea12f10..fcbaff8 100644
--- a/kernel/drivers/tty/serial/ar933x_uart.c
+++ b/kernel/drivers/tty/serial/ar933x_uart.c
@@ -13,6 +13,7 @@
#include <linux/console.h>
#include <linux/sysrq.h>
#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
#include <linux/platform_device.h>
#include <linux/of.h>
#include <linux/of_platform.h>
@@ -28,6 +29,8 @@
#include <asm/div64.h>
#include <asm/mach-ath79/ar933x_uart.h>
+
+#include "serial_mctrl_gpio.h"
#define DRIVER_NAME "ar933x-uart"
@@ -47,6 +50,8 @@
unsigned int min_baud;
unsigned int max_baud;
struct clk *clk;
+ struct mctrl_gpios *gpios;
+ struct gpio_desc *rts_gpiod;
};
static inline unsigned int ar933x_uart_read(struct ar933x_uart_port *up,
@@ -100,6 +105,18 @@
ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
}
+static inline void ar933x_uart_start_rx_interrupt(struct ar933x_uart_port *up)
+{
+ up->ier |= AR933X_UART_INT_RX_VALID;
+ ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
+}
+
+static inline void ar933x_uart_stop_rx_interrupt(struct ar933x_uart_port *up)
+{
+ up->ier &= ~AR933X_UART_INT_RX_VALID;
+ ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
+}
+
static inline void ar933x_uart_putc(struct ar933x_uart_port *up, int ch)
{
unsigned int rdata;
@@ -125,11 +142,21 @@
static unsigned int ar933x_uart_get_mctrl(struct uart_port *port)
{
- return TIOCM_CAR;
+ struct ar933x_uart_port *up =
+ container_of(port, struct ar933x_uart_port, port);
+ int ret = TIOCM_CTS | TIOCM_DSR | TIOCM_CAR;
+
+ mctrl_gpio_get(up->gpios, &ret);
+
+ return ret;
}
static void ar933x_uart_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
+ struct ar933x_uart_port *up =
+ container_of(port, struct ar933x_uart_port, port);
+
+ mctrl_gpio_set(up->gpios, mctrl);
}
static void ar933x_uart_start_tx(struct uart_port *port)
@@ -138,6 +165,37 @@
container_of(port, struct ar933x_uart_port, port);
ar933x_uart_start_tx_interrupt(up);
+}
+
+static void ar933x_uart_wait_tx_complete(struct ar933x_uart_port *up)
+{
+ unsigned int status;
+ unsigned int timeout = 60000;
+
+ /* Wait up to 60ms for the character(s) to be sent. */
+ do {
+ status = ar933x_uart_read(up, AR933X_UART_CS_REG);
+ if (--timeout == 0)
+ break;
+ udelay(1);
+ } while (status & AR933X_UART_CS_TX_BUSY);
+
+ if (timeout == 0)
+ dev_err(up->port.dev, "waiting for TX timed out\n");
+}
+
+static void ar933x_uart_rx_flush(struct ar933x_uart_port *up)
+{
+ unsigned int status;
+
+ /* clear RX_VALID interrupt */
+ ar933x_uart_write(up, AR933X_UART_INT_REG, AR933X_UART_INT_RX_VALID);
+
+ /* remove characters from the RX FIFO */
+ do {
+ ar933x_uart_write(up, AR933X_UART_DATA_REG, AR933X_UART_DATA_RX_CSR);
+ status = ar933x_uart_read(up, AR933X_UART_DATA_REG);
+ } while (status & AR933X_UART_DATA_RX_CSR);
}
static void ar933x_uart_stop_tx(struct uart_port *port)
@@ -153,8 +211,7 @@
struct ar933x_uart_port *up =
container_of(port, struct ar933x_uart_port, port);
- up->ier &= ~AR933X_UART_INT_RX_VALID;
- ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
+ ar933x_uart_stop_rx_interrupt(up);
}
static void ar933x_uart_break_ctl(struct uart_port *port, int break_state)
@@ -336,10 +393,19 @@
static void ar933x_uart_tx_chars(struct ar933x_uart_port *up)
{
struct circ_buf *xmit = &up->port.state->xmit;
+ struct serial_rs485 *rs485conf = &up->port.rs485;
int count;
+ bool half_duplex_send = false;
if (uart_tx_stopped(&up->port))
return;
+
+ if ((rs485conf->flags & SER_RS485_ENABLED) &&
+ (up->port.x_char || !uart_circ_empty(xmit))) {
+ ar933x_uart_stop_rx_interrupt(up);
+ gpiod_set_value(up->rts_gpiod, !!(rs485conf->flags & SER_RS485_RTS_ON_SEND));
+ half_duplex_send = true;
+ }
count = up->port.fifosize;
do {
@@ -368,8 +434,14 @@
if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
uart_write_wakeup(&up->port);
- if (!uart_circ_empty(xmit))
+ if (!uart_circ_empty(xmit)) {
ar933x_uart_start_tx_interrupt(up);
+ } else if (half_duplex_send) {
+ ar933x_uart_wait_tx_complete(up);
+ ar933x_uart_rx_flush(up);
+ ar933x_uart_start_rx_interrupt(up);
+ gpiod_set_value(up->rts_gpiod, !!(rs485conf->flags & SER_RS485_RTS_AFTER_SEND));
+ }
}
static irqreturn_t ar933x_uart_interrupt(int irq, void *dev_id)
@@ -427,8 +499,7 @@
AR933X_UART_CS_TX_READY_ORIDE | AR933X_UART_CS_RX_READY_ORIDE);
/* Enable RX interrupts */
- up->ier = AR933X_UART_INT_RX_VALID;
- ar933x_uart_write(up, AR933X_UART_INT_EN_REG, up->ier);
+ ar933x_uart_start_rx_interrupt(up);
spin_unlock_irqrestore(&up->port.lock, flags);
@@ -510,6 +581,26 @@
.config_port = ar933x_uart_config_port,
.verify_port = ar933x_uart_verify_port,
};
+
+static int ar933x_config_rs485(struct uart_port *port,
+ struct serial_rs485 *rs485conf)
+{
+ struct ar933x_uart_port *up =
+ container_of(port, struct ar933x_uart_port, port);
+
+ if ((rs485conf->flags & SER_RS485_ENABLED) &&
+ !up->rts_gpiod) {
+ dev_err(port->dev, "RS485 needs rts-gpio\n");
+ return 1;
+ }
+
+ if (rs485conf->flags & SER_RS485_ENABLED)
+ gpiod_set_value(up->rts_gpiod,
+ !!(rs485conf->flags & SER_RS485_RTS_AFTER_SEND));
+
+ port->rs485 = *rs485conf;
+ return 0;
+}
#ifdef CONFIG_SERIAL_AR933X_CONSOLE
static struct ar933x_uart_port *
@@ -690,6 +781,7 @@
port->regshift = 2;
port->fifosize = AR933X_UART_FIFO_SIZE;
port->ops = &ar933x_uart_ops;
+ port->rs485_config = ar933x_config_rs485;
baud = ar933x_uart_get_baud(port->uartclk, AR933X_UART_MAX_SCALE, 1);
up->min_baud = max_t(unsigned int, baud, AR933X_UART_MIN_BAUD);
@@ -697,6 +789,24 @@
baud = ar933x_uart_get_baud(port->uartclk, 0, AR933X_UART_MAX_STEP);
up->max_baud = min_t(unsigned int, baud, AR933X_UART_MAX_BAUD);
+ ret = uart_get_rs485_mode(port);
+ if (ret)
+ goto err_disable_clk;
+
+ up->gpios = mctrl_gpio_init(port, 0);
+ if (IS_ERR(up->gpios) && PTR_ERR(up->gpios) != -ENOSYS) {
+ ret = PTR_ERR(up->gpios);
+ goto err_disable_clk;
+ }
+
+ up->rts_gpiod = mctrl_gpio_to_gpiod(up->gpios, UART_GPIO_RTS);
+
+ if ((port->rs485.flags & SER_RS485_ENABLED) &&
+ !up->rts_gpiod) {
+ dev_err(&pdev->dev, "lacking rts-gpio, disabling RS485\n");
+ port->rs485.flags &= ~SER_RS485_ENABLED;
+ }
+
#ifdef CONFIG_SERIAL_AR933X_CONSOLE
ar933x_console_ports[up->port.line] = up;
#endif
--
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