Add support for DT based early console on platforms with the msm
serial hardware.

Cc: Rob Herring <r...@kernel.org>
Signed-off-by: Stephen Boyd <sb...@codeaurora.org>
---
 drivers/tty/serial/Kconfig      |  1 +
 drivers/tty/serial/msm_serial.c | 72 ++++++++++++++++++++++++++++++++++-------
 2 files changed, 61 insertions(+), 12 deletions(-)

diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 26cec64dadd7..903a3277fa60 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -1051,6 +1051,7 @@ 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 c549110509bb..d68faa2e7a6c 100644
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -856,22 +856,15 @@ 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;
@@ -883,7 +876,7 @@ 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;
@@ -892,7 +885,7 @@ 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;
@@ -921,6 +914,20 @@ 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;
@@ -963,6 +970,47 @@ 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;
+}
+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;
+}
+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 = {
-- 
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by The Linux Foundation

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to