On 10/2/23 1:33 AM, Bartosz Golaszewski wrote: > On Fri, Sep 29, 2023 at 11:38 PM Dipen Patel <dipenp@xxxxxxxxxx> wrote: >> >> On 9/11/23 2:44 AM, Bartosz Golaszewski wrote: >>> From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx> >>> >>> Using any of the GPIO interfaces using the global numberspace is >>> deprecated. Make it clear in the comment. >>> >>> Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx> >>> Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx> >>> --- >>> This was part of a wider series but since this is independent, I'm sending >>> it separately. >>> >>> drivers/hte/hte-tegra194.c | 13 ++++++++----- >>> 1 file changed, 8 insertions(+), 5 deletions(-) >>> >>> diff --git a/drivers/hte/hte-tegra194.c b/drivers/hte/hte-tegra194.c >>> index 6fe6897047ac..9fd3c00ff695 100644 >>> --- a/drivers/hte/hte-tegra194.c >>> +++ b/drivers/hte/hte-tegra194.c >>> @@ -407,12 +407,15 @@ static int tegra_hte_line_xlate(struct hte_chip *gc, >>> return -EINVAL; >>> >>> /* >>> + * GPIO consumers can access GPIOs in two ways: >>> * >>> - * There are two paths GPIO consumers can take as follows: >>> - * 1) The consumer (gpiolib-cdev for example) which uses GPIO global >>> - * number which gets assigned run time. >>> - * 2) The consumer passing GPIO from the DT which is assigned >>> - * statically for example by using TEGRA194_AON_GPIO gpio DT binding. >>> + * 1) Using the global GPIO numberspace. >>> + * >>> + * This is the old, now DEPRECATED method and should not be used in >>> + * new code. TODO: Check if tegra is even concerned by this. >> This use case is to do namespace mapping from gpio subsystem to hte. Few doubts: >> 1. What does deprecate mean here? Does gpio subsys not use global space anymore? > > It does but we don't want to expose this to external users in any way > anymore (and haven't to for years). This is what deprecated means. > Users should deal with opaque GPIO descriptors not global GPIO > numberspace. > >> 2. If yes, what GPIO number is set when it comes from gpiolib-cdev, as based on that I may have to >> reflect in the mapping, tegra194_aon_gpio_map for example. > > Why DO you have to use a GPIO number though? If HTE needs just a > number from some HTE numberspace (which in itself may be unnecessary) > then why not just keep a local IDA for it? Do you have to know the > GPIOs internal numbering scheme to make it work? humm, overall, I just need to know which GPIO it is, for example, GPIO controller X Port A GPIO number 3 to do proper mapping. Continuing from above example, the hte driver gets: - GPIO Controller X from DT node - the rest details in current code gets it from [1] and [2] If there is alternate method exists, I would like to explore. I think IDA will not help in this case as ID assigned does not hold meaning in this context. [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpio/gpiolib-cdev.c?h=v6.6-rc3#n760 [2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/hte/hte-tegra194.c?h=v6.6-rc3#n421 > > Bart > >>> + * >>> + * 2) Using GPIO descriptors that can be assigned to consumer devices >>> + * using device-tree, ACPI or lookup tables. >>> * >>> * The code below addresses both the consumer use cases and maps into >>> * HTE/GTE namespace. >>
