Commit 1f507b3a authored by Valentin Caron's avatar Valentin Caron Committed by Greg Kroah-Hartman
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serial: stm32: add KGDB support 



Add support for KGDB in stm32 serial driver by implementing characters
polling callbacks (poll_init, poll_get_char and poll_put_char).

Signed-off-by: default avatarErwan Le Ray <erwan.leray@foss.st.com>
Signed-off-by: default avatarJean Philippe Romain <jean-philippe.romain@foss.st.com>
Signed-off-by: default avatarValentin Caron <valentin.caron@foss.st.com>
Link: https://lore.kernel.org/r/20220419085330.1178925-3-valentin.caron@foss.st.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 28fb1a92

drivers/tty/serial/stm32-usart.c

+35 −2
Original line number Diff line number Diff line
@@ -37,6 +37,7 @@ 


static void stm32_usart_stop_tx(struct uart_port *port);

static void stm32_usart_transmit_chars(struct uart_port *port);

static void __maybe_unused stm32_usart_console_putchar(struct uart_port *port, unsigned char ch);



static inline struct stm32_port *to_stm32_port(struct uart_port *port)

{
@@ -1217,6 +1218,33 @@ static void stm32_usart_pm(struct uart_port *port, unsigned int state, 
	}

}



#if defined(CONFIG_CONSOLE_POLL)



 /* Callbacks for characters polling in debug context (i.e. KGDB). */

static int stm32_usart_poll_init(struct uart_port *port)

{

	struct stm32_port *stm32_port = to_stm32_port(port);



	return clk_prepare_enable(stm32_port->clk);

}



static int stm32_usart_poll_get_char(struct uart_port *port)

{

	struct stm32_port *stm32_port = to_stm32_port(port);

	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;



	if (!(readl_relaxed(port->membase + ofs->isr) & USART_SR_RXNE))

		return NO_POLL_CHAR;



	return readl_relaxed(port->membase + ofs->rdr) & stm32_port->rdr_mask;

}



static void stm32_usart_poll_put_char(struct uart_port *port, unsigned char ch)

{

	stm32_usart_console_putchar(port, ch);

}

#endif /* CONFIG_CONSOLE_POLL */



static const struct uart_ops stm32_uart_ops = {

	.tx_empty	= stm32_usart_tx_empty,

	.set_mctrl	= stm32_usart_set_mctrl,
@@ -1238,6 +1266,11 @@ static const struct uart_ops stm32_uart_ops = { 
	.request_port	= stm32_usart_request_port,

	.config_port	= stm32_usart_config_port,

	.verify_port	= stm32_usart_verify_port,

#if defined(CONFIG_CONSOLE_POLL)

	.poll_init      = stm32_usart_poll_init,

	.poll_get_char	= stm32_usart_poll_get_char,

	.poll_put_char	= stm32_usart_poll_put_char,

#endif /* CONFIG_CONSOLE_POLL */

};



/*
@@ -1635,8 +1668,7 @@ static int stm32_usart_serial_remove(struct platform_device *pdev) 
	return 0;

}



#ifdef CONFIG_SERIAL_STM32_CONSOLE

static void stm32_usart_console_putchar(struct uart_port *port, unsigned char ch)

static void __maybe_unused stm32_usart_console_putchar(struct uart_port *port, unsigned char ch)

{

	struct stm32_port *stm32_port = to_stm32_port(port);

	const struct stm32_usart_offsets *ofs = &stm32_port->info->ofs;
@@ -1653,6 +1685,7 @@ static void stm32_usart_console_putchar(struct uart_port *port, unsigned char ch 
	writel_relaxed(ch, port->membase + ofs->tdr);

}



#ifdef CONFIG_SERIAL_STM32_CONSOLE

static void stm32_usart_console_write(struct console *co, const char *s,

				      unsigned int cnt)

{