* [PATCH v2 0/2] earlycon: Let users set the clock frequency
@ 2022-11-24 10:02 Ricardo Ribalda
2022-11-24 10:02 ` [PATCH v2 1/2] earlycon: Replace simple_strtoul with kstrtouint Ricardo Ribalda
2022-11-24 10:02 ` [PATCH v2 2/2] earlycon: Let users set the clock frequency Ricardo Ribalda
0 siblings, 2 replies; 5+ messages in thread
From: Ricardo Ribalda @ 2022-11-24 10:02 UTC (permalink / raw)
To: Greg Kroah-Hartman, Jiri Slaby, Jonathan Corbet
Cc: Ricardo Ribalda, linux-doc, linux-serial, linux-kernel
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 <corbet@lwn.net>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: Jiri Slaby <jirislaby@kernel.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-serial@vger.kernel.org
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
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/20221123-serial-clk-v1-0-1f0554a46ad1@chromium.org
---
Ricardo Ribalda (2):
earlycon: Replace simple_strtoul with kstrtouint
earlycon: Let users set the clock frequency
Documentation/admin-guide/kernel-parameters.txt | 12 +++++++-----
drivers/tty/serial/earlycon.c | 17 ++++++++++++++---
2 files changed, 21 insertions(+), 8 deletions(-)
---
base-commit: 4312098baf37ee17a8350725e6e0d0e8590252d4
change-id: 20221123-serial-clk-85db701ada57
Best regards,
--
Ricardo Ribalda <ribalda@chromium.org>
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH v2 1/2] earlycon: Replace simple_strtoul with kstrtouint 2022-11-24 10:02 [PATCH v2 0/2] earlycon: Let users set the clock frequency Ricardo Ribalda @ 2022-11-24 10:02 ` Ricardo Ribalda 2022-11-24 10:02 ` [PATCH v2 2/2] earlycon: Let users set the clock frequency Ricardo Ribalda 1 sibling, 0 replies; 5+ messages in thread From: Ricardo Ribalda @ 2022-11-24 10:02 UTC (permalink / raw) To: Greg Kroah-Hartman, Jiri Slaby, Jonathan Corbet Cc: Ricardo Ribalda, linux-doc, linux-serial, linux-kernel Baud rate is declared as unsigned integer. Use the right function. Signed-off-by: Ricardo Ribalda <ribalda@chromium.org> diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c index a5f380584cda..5b73da9487b1 100644 --- a/drivers/tty/serial/earlycon.c +++ b/drivers/tty/serial/earlycon.c @@ -120,7 +120,9 @@ static int __init parse_options(struct earlycon_device *device, char *options) } if (options) { - device->baud = simple_strtoul(options, NULL, 0); + if (kstrtouint(options, 0, &device->baud) < 0) + pr_warn("[%s] unsupported earlycon baud rate option\n", + options); length = min(strcspn(options, " ") + 1, (size_t)(sizeof(device->options))); strscpy(device->options, options, length); @@ -303,7 +305,9 @@ int __init of_setup_earlycon(const struct earlycon_id *match, port->uartclk = be32_to_cpu(*val); if (options) { - early_console_dev.baud = simple_strtoul(options, NULL, 0); + if (kstrtouint(options, 0, &early_console_dev.baud) < 0) + pr_warn("[%s] unsupported earlycon baud rate options\n", + options); strscpy(early_console_dev.options, options, sizeof(early_console_dev.options)); } -- b4 0.11.0-dev-d93f8 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCH v2 2/2] earlycon: Let users set the clock frequency 2022-11-24 10:02 [PATCH v2 0/2] earlycon: Let users set the clock frequency Ricardo Ribalda 2022-11-24 10:02 ` [PATCH v2 1/2] earlycon: Replace simple_strtoul with kstrtouint Ricardo Ribalda @ 2022-11-24 10:02 ` Ricardo Ribalda 2022-11-24 11:19 ` Jiri Slaby 1 sibling, 1 reply; 5+ messages in thread From: Ricardo Ribalda @ 2022-11-24 10:02 UTC (permalink / raw) To: Greg Kroah-Hartman, Jiri Slaby, Jonathan Corbet Cc: Ricardo Ribalda, linux-doc, linux-serial, linux-kernel 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 <ribalda@chromium.org> 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 5b73da9487b1..2db92d36351b 100644 --- a/drivers/tty/serial/earlycon.c +++ b/drivers/tty/serial/earlycon.c @@ -120,9 +120,15 @@ static int __init parse_options(struct earlycon_device *device, char *options) } if (options) { + char *uartclk; + if (kstrtouint(options, 0, &device->baud) < 0) pr_warn("[%s] unsupported earlycon baud rate option\n", options); + uartclk = strchr(options, ','); + if (uartclk && kstrtouint(uartclk, 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); @@ -141,7 +147,8 @@ 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 ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v2 2/2] earlycon: Let users set the clock frequency 2022-11-24 10:02 ` [PATCH v2 2/2] earlycon: Let users set the clock frequency Ricardo Ribalda @ 2022-11-24 11:19 ` Jiri Slaby 2022-11-24 12:10 ` Ricardo Ribalda 0 siblings, 1 reply; 5+ messages in thread From: Jiri Slaby @ 2022-11-24 11:19 UTC (permalink / raw) To: Ricardo Ribalda, Greg Kroah-Hartman, Jonathan Corbet Cc: linux-doc, linux-serial, linux-kernel Hi, On 24. 11. 22, 11:02, Ricardo Ribalda wrote: ... > --- a/drivers/tty/serial/earlycon.c > +++ b/drivers/tty/serial/earlycon.c > @@ -120,9 +120,15 @@ static int __init parse_options(struct earlycon_device *device, char *options) > } > > if (options) { > + char *uartclk; > + > if (kstrtouint(options, 0, &device->baud) < 0) > pr_warn("[%s] unsupported earlycon baud rate option\n", > options); IMO this won't work if there is a comma in options (i.e. your new clkrate param). kstrtouint will return -EINVAL in that case. > + uartclk = strchr(options, ','); > + if (uartclk && kstrtouint(uartclk, 0, &port->uartclk) < 0) You are giving ",number" to kstrtouint, right? That won't work either ;). regards, -- js ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2 2/2] earlycon: Let users set the clock frequency 2022-11-24 11:19 ` Jiri Slaby @ 2022-11-24 12:10 ` Ricardo Ribalda 0 siblings, 0 replies; 5+ messages in thread From: Ricardo Ribalda @ 2022-11-24 12:10 UTC (permalink / raw) To: Jiri Slaby Cc: Greg Kroah-Hartman, Jonathan Corbet, linux-doc, linux-serial, linux-kernel On Thu, 24 Nov 2022 at 12:19, Jiri Slaby <jirislaby@kernel.org> wrote: > > Hi, > > On 24. 11. 22, 11:02, Ricardo Ribalda wrote: > ... > > --- a/drivers/tty/serial/earlycon.c > > +++ b/drivers/tty/serial/earlycon.c > > @@ -120,9 +120,15 @@ static int __init parse_options(struct earlycon_device *device, char *options) > > } > > > > if (options) { > > + char *uartclk; > > + > > if (kstrtouint(options, 0, &device->baud) < 0) > > pr_warn("[%s] unsupported earlycon baud rate option\n", > > options); > > IMO this won't work if there is a comma in options (i.e. your new > clkrate param). kstrtouint will return -EINVAL in that case. > > > + uartclk = strchr(options, ','); > > + if (uartclk && kstrtouint(uartclk, 0, &port->uartclk) < 0) > > You are giving ",number" to kstrtouint, right? That won't work either ;). The fun thing is that it worked because it fell back to the acpi parameters :). Will send a v3 Thanks! > > regards, > -- > js > -- Ricardo Ribalda ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2022-11-24 12:10 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2022-11-24 10:02 [PATCH v2 0/2] earlycon: Let users set the clock frequency Ricardo Ribalda 2022-11-24 10:02 ` [PATCH v2 1/2] earlycon: Replace simple_strtoul with kstrtouint Ricardo Ribalda 2022-11-24 10:02 ` [PATCH v2 2/2] earlycon: Let users set the clock frequency Ricardo Ribalda 2022-11-24 11:19 ` Jiri Slaby 2022-11-24 12:10 ` Ricardo Ribalda
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