* [PATCH/RESEND] tty: serial: msm: Add DT based earlycon support
@ 2014-09-11 22:14 Stephen Boyd
2014-09-12 1:56 ` Rob Herring
0 siblings, 1 reply; 3+ messages in thread
From: Stephen Boyd @ 2014-09-11 22:14 UTC (permalink / raw)
To: linux-arm-kernel
Add support for DT based early console on platforms with the msm
serial hardware.
Cc: Rob Herring <robh@kernel.org>
Signed-off-by: Stephen Boyd <sboyd@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
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH/RESEND] tty: serial: msm: Add DT based earlycon support
2014-09-11 22:14 [PATCH/RESEND] tty: serial: msm: Add DT based earlycon support Stephen Boyd
@ 2014-09-12 1:56 ` Rob Herring
2014-09-12 17:26 ` Stephen Boyd
0 siblings, 1 reply; 3+ messages in thread
From: Rob Herring @ 2014-09-12 1:56 UTC (permalink / raw)
To: linux-arm-kernel
On Thu, Sep 11, 2014 at 5:14 PM, Stephen Boyd <sboyd@codeaurora.org> wrote:
> Add support for DT based early console on platforms with the msm
> serial hardware.
>
> Cc: Rob Herring <robh@kernel.org>
> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
One comment, but looks good to me.
Acked-by: Rob Herring <robh@kernel.org>
> +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);
Don't you want to support kernel command line as well? Then if you
can't change the DT or bootloader's command line, you can add it into
the kernel build with the appended command line. Don't forget to
document it in kernel-parameters.txt if you do.
Rob
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH/RESEND] tty: serial: msm: Add DT based earlycon support
2014-09-12 1:56 ` Rob Herring
@ 2014-09-12 17:26 ` Stephen Boyd
0 siblings, 0 replies; 3+ messages in thread
From: Stephen Boyd @ 2014-09-12 17:26 UTC (permalink / raw)
To: linux-arm-kernel
On 09/11/14 18:56, Rob Herring wrote:
> On Thu, Sep 11, 2014 at 5:14 PM, Stephen Boyd <sboyd@codeaurora.org> wrote:
>> Add support for DT based early console on platforms with the msm
>> serial hardware.
>>
>> Cc: Rob Herring <robh@kernel.org>
>> Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
> One comment, but looks good to me.
>
> Acked-by: Rob Herring <robh@kernel.org>
Thanks.
>> +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);
> Don't you want to support kernel command line as well? Then if you
> can't change the DT or bootloader's command line, you can add it into
> the kernel build with the appended command line. Don't forget to
> document it in kernel-parameters.txt if you do.
>
>
Ok. Here's the interdiff. I'll send a v2.
---8<----
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 5ae8608ca9f5..22302931e9d4 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -936,6 +936,18 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
must already be setup and configured. Options are not
yet supported.
+ msm_serial,<addr>
+ 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,<addr>
+ 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/msm_serial.c b/drivers/tty/serial/msm_serial.c
index d3881991e8d3..4b6c78331a64 100644
--- a/drivers/tty/serial/msm_serial.c
+++ b/drivers/tty/serial/msm_serial.c
@@ -976,6 +976,7 @@ msm_serial_early_console_setup(struct earlycon_device *device, const char *opt)
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);
@@ -997,6 +998,7 @@ msm_serial_early_console_setup_dm(struct earlycon_device *device,
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);
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
hosted by The Linux Foundation
^ permalink raw reply related [flat|nested] 3+ messages in thread
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2014-09-12 1:56 ` Rob Herring
2014-09-12 17:26 ` Stephen Boyd
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