Some platforms, namely AMD Picasso, use non standard uart clocks (48M),
witch makes it impossible to use with earlycon.
Let the user select its own frequency.
To: Jonathan Corbet <[email protected]>
To: Greg Kroah-Hartman <[email protected]>
To: Jiri Slaby <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Ricardo Ribalda <[email protected]>
---
Changes in v3:
- Revert patch to use kstrtouint for baudrate
- Parse the number not the ,number (Thanks Jiri :) )
- Add optional patch to increase the options size
- Link to v2: https://lore.kernel.org/r/[email protected]
Changes in v2:
- Add a patch to fix handling of baudrate
- Use kstrtouint instead of simple_strtoul
- Link to v1: https://lore.kernel.org/r/[email protected]
---
Ricardo Ribalda (2):
earlycon: Let users set the clock frequency
earlycon: Increase options size
Documentation/admin-guide/kernel-parameters.txt | 12 +++++++-----
drivers/tty/serial/earlycon.c | 9 ++++++++-
include/linux/serial_core.h | 2 +-
3 files changed, 16 insertions(+), 7 deletions(-)
---
base-commit: 4312098baf37ee17a8350725e6e0d0e8590252d4
change-id: 20221123-serial-clk-85db701ada57
Best regards,
--
Ricardo Ribalda <[email protected]>
Some platforms, namely AMD Picasso, use non standard uart clocks (48M),
witch makes it impossible to use with earlycon.
Let the user select its own frequency.
Signed-off-by: Ricardo Ribalda <[email protected]>
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index a465d5242774..9efb6c3b0486 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -1182,10 +1182,10 @@
specified, the serial port must already be setup and
configured.
- uart[8250],io,<addr>[,options]
- uart[8250],mmio,<addr>[,options]
- uart[8250],mmio32,<addr>[,options]
- uart[8250],mmio32be,<addr>[,options]
+ uart[8250],io,<addr>[,options[,uartclk]]
+ uart[8250],mmio,<addr>[,options[,uartclk]]
+ uart[8250],mmio32,<addr>[,options[,uartclk]]
+ uart[8250],mmio32be,<addr>[,options[,uartclk]]
uart[8250],0x<addr>[,options]
Start an early, polled-mode console on the 8250/16550
UART at the specified I/O port or MMIO address.
@@ -1194,7 +1194,9 @@
If none of [io|mmio|mmio32|mmio32be], <addr> is assumed
to be equivalent to 'mmio'. 'options' are specified
in the same format described for "console=ttyS<n>"; if
- unspecified, the h/w is not initialized.
+ unspecified, the h/w is not initialized. 'uartclk' is
+ the uart clock frequency; if unspecified, it is set
+ to 'BASE_BAUD' * 16.
pl011,<addr>
pl011,mmio32,<addr>
diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index a5f380584cda..3a0c88419b6c 100644
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -120,7 +120,13 @@ static int __init parse_options(struct earlycon_device *device, char *options)
}
if (options) {
+ char *uartclk;
+
device->baud = simple_strtoul(options, NULL, 0);
+ uartclk = strchr(options, ',');
+ if (uartclk && kstrtouint(uartclk + 1, 0, &port->uartclk) < 0)
+ pr_warn("[%s] unsupported earlycon uart clkrate option\n",
+ options);
length = min(strcspn(options, " ") + 1,
(size_t)(sizeof(device->options)));
strscpy(device->options, options, length);
@@ -139,7 +145,8 @@ static int __init register_earlycon(char *buf, const struct earlycon_id *match)
buf = NULL;
spin_lock_init(&port->lock);
- port->uartclk = BASE_BAUD * 16;
+ if (!port->uartclk)
+ port->uartclk = BASE_BAUD * 16;
if (port->mapbase)
port->membase = earlycon_map(port->mapbase, 64);
--
b4 0.11.0-dev-d93f8
Now that the clock frequency is also part of the options, 16 bytes is
too little.
Without this patch dmesg does not show the whole options, Eg:
earlycon: uart0 at MMIO32 0x00000000fedc9000 (options '115200n8,480000')
instead of: '115200n8,48000000'
Signed-off-by: Ricardo Ribalda <[email protected]>
diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index d657f2a42a7b..f555927195da 100644
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -701,7 +701,7 @@ static inline int uart_poll_timeout(struct uart_port *port)
struct earlycon_device {
struct console *con;
struct uart_port port;
- char options[16]; /* e.g., 115200n8 */
+ char options[32]; /* e.g., 115200n8 */
unsigned int baud;
};
--
b4 0.11.0-dev-d93f8
Hi Jiri
is there something else that I am missing here?
Thanks!
On Thu, 24 Nov 2022 at 13:39, Ricardo Ribalda <[email protected]> wrote:
>
> Some platforms, namely AMD Picasso, use non standard uart clocks (48M),
> witch makes it impossible to use with earlycon.
>
> Let the user select its own frequency.
>
> Signed-off-by: Ricardo Ribalda <[email protected]>
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index a465d5242774..9efb6c3b0486 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -1182,10 +1182,10 @@
> specified, the serial port must already be setup and
> configured.
>
> - uart[8250],io,<addr>[,options]
> - uart[8250],mmio,<addr>[,options]
> - uart[8250],mmio32,<addr>[,options]
> - uart[8250],mmio32be,<addr>[,options]
> + uart[8250],io,<addr>[,options[,uartclk]]
> + uart[8250],mmio,<addr>[,options[,uartclk]]
> + uart[8250],mmio32,<addr>[,options[,uartclk]]
> + uart[8250],mmio32be,<addr>[,options[,uartclk]]
> uart[8250],0x<addr>[,options]
> Start an early, polled-mode console on the 8250/16550
> UART at the specified I/O port or MMIO address.
> @@ -1194,7 +1194,9 @@
> If none of [io|mmio|mmio32|mmio32be], <addr> is assumed
> to be equivalent to 'mmio'. 'options' are specified
> in the same format described for "console=ttyS<n>"; if
> - unspecified, the h/w is not initialized.
> + unspecified, the h/w is not initialized. 'uartclk' is
> + the uart clock frequency; if unspecified, it is set
> + to 'BASE_BAUD' * 16.
>
> pl011,<addr>
> pl011,mmio32,<addr>
> diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
> index a5f380584cda..3a0c88419b6c 100644
> --- a/drivers/tty/serial/earlycon.c
> +++ b/drivers/tty/serial/earlycon.c
> @@ -120,7 +120,13 @@ static int __init parse_options(struct earlycon_device *device, char *options)
> }
>
> if (options) {
> + char *uartclk;
> +
> device->baud = simple_strtoul(options, NULL, 0);
> + uartclk = strchr(options, ',');
> + if (uartclk && kstrtouint(uartclk + 1, 0, &port->uartclk) < 0)
> + pr_warn("[%s] unsupported earlycon uart clkrate option\n",
> + options);
> length = min(strcspn(options, " ") + 1,
> (size_t)(sizeof(device->options)));
> strscpy(device->options, options, length);
> @@ -139,7 +145,8 @@ static int __init register_earlycon(char *buf, const struct earlycon_id *match)
> buf = NULL;
>
> spin_lock_init(&port->lock);
> - port->uartclk = BASE_BAUD * 16;
> + if (!port->uartclk)
> + port->uartclk = BASE_BAUD * 16;
> if (port->mapbase)
> port->membase = earlycon_map(port->mapbase, 64);
>
>
> --
> b4 0.11.0-dev-d93f8
--
Ricardo Ribalda
On 24. 11. 22, 13:39, Ricardo Ribalda wrote:
> Some platforms, namely AMD Picasso, use non standard uart clocks (48M),
> witch makes it impossible to use with earlycon.
>
> Let the user select its own frequency.
>
> Signed-off-by: Ricardo Ribalda <[email protected]>
Reviewed-by: Jiri Slaby <[email protected]>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index a465d5242774..9efb6c3b0486 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -1182,10 +1182,10 @@
> specified, the serial port must already be setup and
> configured.
>
> - uart[8250],io,<addr>[,options]
> - uart[8250],mmio,<addr>[,options]
> - uart[8250],mmio32,<addr>[,options]
> - uart[8250],mmio32be,<addr>[,options]
> + uart[8250],io,<addr>[,options[,uartclk]]
> + uart[8250],mmio,<addr>[,options[,uartclk]]
> + uart[8250],mmio32,<addr>[,options[,uartclk]]
> + uart[8250],mmio32be,<addr>[,options[,uartclk]]
> uart[8250],0x<addr>[,options]
> Start an early, polled-mode console on the 8250/16550
> UART at the specified I/O port or MMIO address.
> @@ -1194,7 +1194,9 @@
> If none of [io|mmio|mmio32|mmio32be], <addr> is assumed
> to be equivalent to 'mmio'. 'options' are specified
> in the same format described for "console=ttyS<n>"; if
> - unspecified, the h/w is not initialized.
> + unspecified, the h/w is not initialized. 'uartclk' is
> + the uart clock frequency; if unspecified, it is set
> + to 'BASE_BAUD' * 16.
>
> pl011,<addr>
> pl011,mmio32,<addr>
> diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
> index a5f380584cda..3a0c88419b6c 100644
> --- a/drivers/tty/serial/earlycon.c
> +++ b/drivers/tty/serial/earlycon.c
> @@ -120,7 +120,13 @@ static int __init parse_options(struct earlycon_device *device, char *options)
> }
>
> if (options) {
> + char *uartclk;
> +
> device->baud = simple_strtoul(options, NULL, 0);
> + uartclk = strchr(options, ',');
> + if (uartclk && kstrtouint(uartclk + 1, 0, &port->uartclk) < 0)
> + pr_warn("[%s] unsupported earlycon uart clkrate option\n",
> + options);
> length = min(strcspn(options, " ") + 1,
> (size_t)(sizeof(device->options)));
> strscpy(device->options, options, length);
> @@ -139,7 +145,8 @@ static int __init register_earlycon(char *buf, const struct earlycon_id *match)
> buf = NULL;
>
> spin_lock_init(&port->lock);
> - port->uartclk = BASE_BAUD * 16;
> + if (!port->uartclk)
> + port->uartclk = BASE_BAUD * 16;
> if (port->mapbase)
> port->membase = earlycon_map(port->mapbase, 64);
>
>
--
js
suse labs
On 24. 11. 22, 13:39, Ricardo Ribalda wrote:
> Now that the clock frequency is also part of the options, 16 bytes is
> too little.
>
> Without this patch dmesg does not show the whole options, Eg:
>
> earlycon: uart0 at MMIO32 0x00000000fedc9000 (options '115200n8,480000')
>
> instead of: '115200n8,48000000'
>
> Signed-off-by: Ricardo Ribalda <[email protected]>
Reviewed-by: Jiri Slaby <[email protected]>
> diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
> index d657f2a42a7b..f555927195da 100644
> --- a/include/linux/serial_core.h
> +++ b/include/linux/serial_core.h
> @@ -701,7 +701,7 @@ static inline int uart_poll_timeout(struct uart_port *port)
> struct earlycon_device {
> struct console *con;
> struct uart_port port;
> - char options[16]; /* e.g., 115200n8 */
> + char options[32]; /* e.g., 115200n8 */
> unsigned int baud;
> };
>
>
--
js
suse labs
On Fri, Dec 02, 2022 at 06:24:19PM +0100, Ricardo Ribalda wrote:
> Hi Jiri
>
> is there something else that I am missing here?
Sorry, been busy with other reviews. I will queue this up after 6.2-rc1
is out, thanks.
greg k-h