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| author |   Valentin Caron <valentin.caron@foss.st.com> | 2022-04-19 10:53:29 +0200 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-22 16:36:23 +0200 |
| commit | 1f507b3aecb3245177ca9012dfe08117bb7925e8 (patch) | |
| tree | d0915fb3a64a342bfb10287b909d380a3c2bfa36 /drivers/tty/serial/stm32-usart.c | |
| parent | serial: stm32: remove infinite loop possibility in putchar function (diff) | |
| download | linux-dev-1f507b3aecb3245177ca9012dfe08117bb7925e8.tar.xz linux-dev-1f507b3aecb3245177ca9012dfe08117bb7925e8.zip | |
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: Erwan Le Ray <erwan.leray@foss.st.com>
Signed-off-by: Jean Philippe Romain <jean-philippe.romain@foss.st.com>
Signed-off-by: Valentin Caron <valentin.caron@foss.st.com>
Link: https://lore.kernel.org/r/20220419085330.1178925-3-valentin.caron@foss.st.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial/stm32-usart.c')
| -rw-r--r-- | drivers/tty/serial/stm32-usart.c | 37 |
1 files changed, 35 insertions, 2 deletions
diff --git a/drivers/tty/serial/stm32-usart.c b/drivers/tty/serial/stm32-usart.c index 9910a18779af..8aefb286bd88 100644 --- a/drivers/tty/serial/stm32-usart.c +++ b/drivers/tty/serial/stm32-usart.c @@ -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) { |