On 11/23/20 2:14 AM, Vabhav Sharma (OSS) wrote:
-----Original Message----- From: Sean Anderson seanga2@gmail.com Sent: Thursday, November 19, 2020 9:01 AM To: Vabhav Sharma (OSS) vabhav.sharma@oss.nxp.com; sjg@chromium.org; sr@denx.de Cc: u-boot@lists.denx.de; Varun Sethi V.Sethi@nxp.com; andre.przywara@arm.com; Vabhav Sharma vabhav.sharma@nxp.com Subject: Re: [PATCH v4 2/2] drivers: serial: probe all uart devices
On 11/17/20 10:00 AM, Vabhav Sharma wrote:
From: Vabhav Sharma vabhav.sharma@nxp.com
U-Boot DM model probe only single device at a time which is enabled and configured using device tree or platform data method.
PL011 UART IP is SBSA compliant and firmware does the serial port set-up, initialization and let the kernel use UART port for sending and receiving characters.
Normally software talk to one serial port time but some LayerScape platform require all the UART devices enabled in Linux for various use case.
Adding support to probe all enabled serial devices like SBSA compliant PL011 UART ports probe and initialization by firmware.
Signed-off-by: Vabhav Sharma vabhav.sharma@nxp.com Reviewed-by: Stefan Roese sr@denx.de Reviewed-by: Simon Glass sjg@chromium.org -- v3: Incorporated Simon and Stephan review comment
- Define generic function uclass_probe_all(enum uclass_id) in drivers/core/uclass.c
- Added the function in caller of serial_find_console_or_panic()
- Removed repeated sequence with generic function call uclass_probe_all()
- Dependent on other patch [PATCH] dm: core: add function
uclass_probe_all()
to probe all devicesv2: Incorporated Stefan review comment, Update #ifdef with macro if (IS_ENABLED)..
drivers/serial/Kconfig | 17 +++++++++++++++++ drivers/serial/serial-uclass.c | 4 ++++ 2 files changed, 21 insertions(+)
diff --git a/drivers/serial/Kconfig b/drivers/serial/Kconfig index b4805a2..af8779b 100644 --- a/drivers/serial/Kconfig +++ b/drivers/serial/Kconfig @@ -134,6 +134,23 @@ config SERIAL_SEARCH_ALL
If unsure, say N.+config SERIAL_PROBE_ALL
- bool "Probe all available serial devices"
- depends on DM_SERIAL
- default n
- help
The serial subsystem only probe for single serial device,nit: probes for a
Ok
but does not probe for other remaining serial devices.With this option set,we make probing and searching fornit: set, we
Sure
all available devices optional.Normally, U-Boot talk to one serial port at a time but SBSAnit: talks nit: time, but
Agree
compliant UART devices like PL011 require initializationby firmware and let the kernel use serial port for sendingnit: to let the kernel use the
I understand
and receiving the characters.If probing is not required for all remaining availabledevices other than default current console device, say N.Perhaps use the "If unsure, say N." wording like other Kconfigs.
Got it
- config SPL_DM_SERIAL bool "Enable Driver Model for serial drivers in SPL" depends on DM_SERIAL && SPL_DM
diff --git a/drivers/serial/serial-uclass.c b/drivers/serial/serial-uclass.c index f3c25d4..417d3af 100644 --- a/drivers/serial/serial-uclass.c +++ b/drivers/serial/serial-uclass.c @@ -172,6 +172,10 @@ int serial_init(void) /* Called after relocation */ int serial_initialize(void) {
- /* Scanning uclass to probe devices */
- if (IS_ENABLED(CONFIG_SERIAL_PROBE_ALL))
uclass_probe_all(UCLASS_SERIAL);
Note that you will also need to check the return value here. E.g.
if (IS_ENABLED(CONFIG_SERIAL_PROBE_ALL)) int ret = uclass_probe_all(UCLASS_SERIAL); if (ret) return ret;
return serial_init(); }