From 0efe72963409739778e93d8e2046305bc8310e83 Mon Sep 17 00:00:00 2001 From: Stephen Boyd Date: Mon, 15 Sep 2014 17:22:51 -0700 Subject: [PATCH] tty: serial: msm: Add earlycon support Add support for DT based and command line based early console on platforms with the msm serial hardware. Cc: Rob Herring Signed-off-by: Stephen Boyd Signed-off-by: Greg Kroah-Hartman --- Documentation/kernel-parameters.txt | 12 +++++ drivers/tty/serial/Kconfig | 1 + drivers/tty/serial/msm_serial.c | 74 ++++++++++++++++++++++++----- 3 files changed, 75 insertions(+), 12 deletions(-) diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index adc1cd7c3bc7..67e93f139b57 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -942,6 +942,18 @@ bytes respectively. Such letter suffixes can also be entirely omitted. must already be setup and configured. Options are not yet supported. + msm_serial, + Start an early, polled-mode console on an msm serial + port at the specified address. The serial port + must already be setup and configured. Options are not + yet supported. + + msm_serial_dm, + Start an early, polled-mode console on an msm serial + dm port at the specified address. The serial port + must already be setup and configured. Options are not + yet supported. + smh Use ARM semihosting calls for early console. earlyprintk= [X86,SH,BLACKFIN,ARM,M68k] diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig index 02a896f4dbcd..649b784081c7 100644 --- a/drivers/tty/serial/Kconfig +++ b/drivers/tty/serial/Kconfig @@ -1070,6 +1070,7 @@ config SERIAL_MSM_CONSOLE bool "MSM serial console support" depends on SERIAL_MSM=y select SERIAL_CORE_CONSOLE + select SERIAL_EARLYCON config SERIAL_MSM_HS tristate "MSM UART High Speed: Serial Driver" diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c index 4f9640d0b1bb..4b6c78331a64 100644 --- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -845,22 +845,15 @@ static inline struct uart_port *get_port_from_line(unsigned int line) } #ifdef CONFIG_SERIAL_MSM_CONSOLE -static void msm_console_write(struct console *co, const char *s, - unsigned int count) +static void __msm_console_write(struct uart_port *port, const char *s, + unsigned int count, bool is_uartdm) { int i; - struct uart_port *port; - struct msm_port *msm_port; int num_newlines = 0; bool replaced = false; void __iomem *tf; - BUG_ON(co->index < 0 || co->index >= UART_NR); - - port = get_port_from_line(co->index); - msm_port = UART_TO_MSM(port); - - if (msm_port->is_uartdm) + if (is_uartdm) tf = port->membase + UARTDM_TF; else tf = port->membase + UART_TF; @@ -872,7 +865,7 @@ static void msm_console_write(struct console *co, const char *s, count += num_newlines; spin_lock(&port->lock); - if (msm_port->is_uartdm) + if (is_uartdm) reset_dm_count(port, count); i = 0; @@ -881,7 +874,7 @@ static void msm_console_write(struct console *co, const char *s, unsigned int num_chars; char buf[4] = { 0 }; - if (msm_port->is_uartdm) + if (is_uartdm) num_chars = min(count - i, (unsigned int)sizeof(buf)); else num_chars = 1; @@ -910,6 +903,20 @@ static void msm_console_write(struct console *co, const char *s, spin_unlock(&port->lock); } +static void msm_console_write(struct console *co, const char *s, + unsigned int count) +{ + struct uart_port *port; + struct msm_port *msm_port; + + BUG_ON(co->index < 0 || co->index >= UART_NR); + + port = get_port_from_line(co->index); + msm_port = UART_TO_MSM(port); + + __msm_console_write(port, s, count, msm_port->is_uartdm); +} + static int __init msm_console_setup(struct console *co, char *options) { struct uart_port *port; @@ -952,6 +959,49 @@ static int __init msm_console_setup(struct console *co, char *options) return uart_set_options(port, co, baud, parity, bits, flow); } +static void +msm_serial_early_write(struct console *con, const char *s, unsigned n) +{ + struct earlycon_device *dev = con->data; + + __msm_console_write(&dev->port, s, n, false); +} + +static int __init +msm_serial_early_console_setup(struct earlycon_device *device, const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = msm_serial_early_write; + return 0; +} +EARLYCON_DECLARE(msm_serial, msm_serial_early_console_setup); +OF_EARLYCON_DECLARE(msm_serial, "qcom,msm-uart", + msm_serial_early_console_setup); + +static void +msm_serial_early_write_dm(struct console *con, const char *s, unsigned n) +{ + struct earlycon_device *dev = con->data; + + __msm_console_write(&dev->port, s, n, true); +} + +static int __init +msm_serial_early_console_setup_dm(struct earlycon_device *device, + const char *opt) +{ + if (!device->port.membase) + return -ENODEV; + + device->con->write = msm_serial_early_write_dm; + return 0; +} +EARLYCON_DECLARE(msm_serial_dm, msm_serial_early_console_setup_dm); +OF_EARLYCON_DECLARE(msm_serial_dm, "qcom,msm-uartdm", + msm_serial_early_console_setup_dm); + static struct uart_driver msm_uart_driver; static struct console msm_console = { -- GitLab