From: Douglas Anderson Date: Thu, 7 May 2020 20:08:48 +0000 (-0700) Subject: serial: qcom_geni_serial: Support kgdboc_earlycon X-Git-Tag: v5.8-rc1~170^2~4 X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=205b5bdda2090d4730dabf9c0d9646cb32f2551d;p=users%2Fjedix%2Flinux-maple.git serial: qcom_geni_serial: Support kgdboc_earlycon Implement the read() function in the early console driver. With recent kgdb patches this allows you to use kgdb to debug fairly early into the system boot. We only bother implementing this if polling is enabled since kgdb can't be enabled without that. Signed-off-by: Douglas Anderson Reviewed-by: Greg Kroah-Hartman Link: https://lore.kernel.org/r/20200507130644.v4.10.If2deff9679a62c1ce1b8f2558a8635dc837adf8c@changeid Signed-off-by: Daniel Thompson --- diff --git a/drivers/tty/serial/qcom_geni_serial.c b/drivers/tty/serial/qcom_geni_serial.c index 6119090ce045d..6bace1c6bb09a 100644 --- a/drivers/tty/serial/qcom_geni_serial.c +++ b/drivers/tty/serial/qcom_geni_serial.c @@ -1090,6 +1090,36 @@ static void qcom_geni_serial_earlycon_write(struct console *con, __qcom_geni_serial_console_write(&dev->port, s, n); } +#ifdef CONFIG_CONSOLE_POLL +static int qcom_geni_serial_earlycon_read(struct console *con, + char *s, unsigned int n) +{ + struct earlycon_device *dev = con->data; + struct uart_port *uport = &dev->port; + int num_read = 0; + int ch; + + while (num_read < n) { + ch = qcom_geni_serial_get_char(uport); + if (ch == NO_POLL_CHAR) + break; + s[num_read++] = ch; + } + + return num_read; +} + +static void __init qcom_geni_serial_enable_early_read(struct geni_se *se, + struct console *con) +{ + geni_se_setup_s_cmd(se, UART_START_READ, 0); + con->read = qcom_geni_serial_earlycon_read; +} +#else +static inline void qcom_geni_serial_enable_early_read(struct geni_se *se, + struct console *con) { } +#endif + static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev, const char *opt) { @@ -1136,6 +1166,8 @@ static int __init qcom_geni_serial_earlycon_setup(struct earlycon_device *dev, dev->con->write = qcom_geni_serial_earlycon_write; dev->con->setup = NULL; + qcom_geni_serial_enable_early_read(&se, dev->con); + return 0; } OF_EARLYCON_DECLARE(qcom_geni, "qcom,geni-debug-uart",