Hi Michal,
On 15 July 2018 at 23:31, Michal Simek michal.simek@xilinx.com wrote:
On 16.7.2018 07:20, Simon Glass wrote:
Hi Michal,
On 13 July 2018 at 03:15, Michal Simek michal.simek@xilinx.com wrote:
The Linux kernel has binding for gpio-restart node. This patch is adding basic support without supporting any optional properties. This driver was tested on Microblaze system where gpio is connected to SoC reset logic. Output value is handled via gpios cells values.
In gpio_reboot_request() set_value is writing 1 because dm_gpio_set_value() is capable to changing it when it is ACTIVE_LOW. ... if (desc->flags & GPIOD_ACTIVE_LOW) value = !value; ...
Signed-off-by: Michal Simek michal.simek@xilinx.com
drivers/sysreset/Kconfig | 6 ++++ drivers/sysreset/Makefile | 1 + drivers/sysreset/sysreset_gpio.c | 59 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 66 insertions(+) create mode 100644 drivers/sysreset/sysreset_gpio.c
Reviewed-by: Simon Glass sjg@chromium.org
But please see below.
diff --git a/drivers/sysreset/Kconfig b/drivers/sysreset/Kconfig index a6d48e8a662c..1e228b97443a 100644 --- a/drivers/sysreset/Kconfig +++ b/drivers/sysreset/Kconfig @@ -15,6 +15,12 @@ config SYSRESET
if SYSRESET
+config SYSRESET_GPIO
bool "Enable support for GPIO restart driver"select GPIOhelpRestart support via GPIO pin connected reset logic.What does this mean? Please expand this to explain what it means.
Also, what is the difference between restart and reset? If there is no difference please use the word 'reset'. If there is a difference, please explain it here.
I have taken restart name because this is what it is written Linux kernel.
Based on this explanation: https://kb.netgear.com/1001/Defining-Terms-Power-Cycle-Boot-Reboot-Restart-R...
"Unlike a reset which changes something, a restart means to turn something on, possibly without changing settings. When upgrading firmware or software you are often asked to restart. A restart would be probably be used if there were a major change to functionality, while a reset often just changes settings of existing functionality."
Perhaps this corresponds to warm and cold reset? I'm not sure. But I don't know of a board which supports resetting without changing anything. At the least the CPU is put back into a start where it can start at its reset vector.
This really doesn't make any sense to me. I think we should stick with 'reset' to avoid confusion. By all means add some notes to the uclass header file about what it should mean. We already have enum sysreset_t, so you could define 'restart' there, perhaps?
Regards, Simon