Re: [PATCH v2 5/7] staging: board: Add support for devices with complex dependencies

From: Geert Uytterhoeven
Date: Mon Sep 07 2015 - 08:08:50 EST

Hi Ulf,

On Mon, Sep 7, 2015 at 1:45 PM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
> On 4 September 2015 at 17:03, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>> On Fri, 4 Sep 2015, Ulf Hansson wrote:
>>> On 3 September 2015 at 15:35, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> wrote:
>>> > On Thu, Sep 3, 2015 at 2:53 PM, Ulf Hansson <ulf.hansson@xxxxxxxxxx> wrote:
>>> >> On 17 June 2015 at 10:38, Geert Uytterhoeven <geert+renesas@xxxxxxxxx> wrote:
>>> >>> Add support for easy registering of one ore more platform devices that
>>> >>> may:
>>> >>> - need clocks that are described in DT,
>>> >>> - be part of a PM Domain.
>>> >
>>> >>> diff --git a/drivers/staging/board/board.c b/drivers/staging/board/board.c
>>> >>> index 8712f566b31196e0..29d456e29f38feac 100644
>>> >>> --- a/drivers/staging/board/board.c
>>> >>> +++ b/drivers/staging/board/board.c
>>> >
>>> >>> +int __init board_staging_register_device(const struct board_staging_dev *dev)
>>> >>> +{
>>> >>> + struct platform_device *pdev = dev->pdev;
>>> >>> + unsigned int i;
>>> >>> + int error;
>>> >>> +
>>> >>> + pr_debug("Trying to register device %s\n", pdev->name);
>>> >>> + if (board_staging_dt_node_available(pdev->resource,
>>> >>> + pdev->num_resources)) {
>>> >>> + pr_warn("Skipping %s, already in DT\n", pdev->name);
>>> >>> + return -EEXIST;
>>> >>> + }
>>> >>> +
>>> >>> + board_staging_gic_fixup_resources(pdev->resource, pdev->num_resources);
>>> >>> +
>>> >>> + for (i = 0; i < dev->nclocks; i++)
>>> >>> + board_staging_register_clock(&dev->clocks[i]);
>>> >>> +
>>> >>> + error = platform_device_register(pdev);
>>> >>> + if (error) {
>>> >>> + pr_err("Failed to register device %s (%d)\n", pdev->name,
>>> >>> + error);
>>> >>> + return error;
>>> >>> + }
>>> >>> +
>>> >>> + if (dev->domain)
>>> >>> + __pm_genpd_name_add_device(dev->domain, &pdev->dev, NULL);
>>> >>
>>> >> Urgh, this managed to slip through my filters.
>>> >>
>>> >> It seems like we almost managed to remove all users of the
>>> >> "..._name_add..." APIs for genpd. If hasn't been for $subject patch.
>>> >> :-)
>>> >>
>>> >> Now, I realize this is already too late here, but let's try to fix
>>> >> this before it turns into a bigger issue.
>>> >>
>>> >> Geert, do you think it's possible to convert into using the non-named
>>> >> bases APIs?
>>> >
>>> > That will be difficult. This code is meant to use drivers that are not yet
>>> > DT-aware on DT-based systems. Hence it uses platform devices with named PM
>>> > domains, while the PM domains are described in DT.
>>> > I don't think there's another way to look up a PM domain by name, is there?
>>>
>>> As a matter of fact there are, especially for those genpds that has
>>> been created through DT as in this case. The API to use is
>>> of_genpd_get_from_provider() to find the struct generic_pm_domain.
>>
>> Thanks!
>>
>>> Yes, I do realize that you need to manage the parsing of the domain
>>> name to make sure it's the one you want, but I would rather keep that
>>> "hack" in this driver than in the generic API.
>>
>> OK. It turned out not to be that complex, cfr. the patch below.
>> For now this supports PM domains with "#power-domain-cells = <0>" only,
>> but of course it can be extended if the need arises.
>>
>> I've also tried:
>>
>> np = of_find_compatible_node(NULL, NULL, "renesas,sysc-rmobile");
>> np = of_find_node_by_name(np, "a4lc");
>>
>> (the second step is needed because of the domain hierarchy in DT), but that
>> would require adding the compatible string to struct board_staging_dev,
>> and doesn't work if you have multiple identical power providers.
>>
>> I hope you like it?
>>
>> From 5fb11904845eb929a5b3382a9d5153c151cde1cf Mon Sep 17 00:00:00 2001
>> From: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
>> Date: Fri, 4 Sep 2015 16:52:33 +0200
>> Subject: [PATCH/RFC] staging: board: Migrate away from
>> __pm_genpd_name_add_device()
>>
>> The named genpd APIs are deprecated. Hence convert the board staging
>> code from using genpd names to DT node paths.
>>
>> For now this supports PM domains with "#power-domain-cells = <0>" only.
>>
>> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
>
> Geert, thanks for posting this patch!
>
> I wonder whether we could get this sent for the 4.3 rc[n], since that
> would enable us to remove some of the named based API for genpd
> through Rafael's linux-pm tree during this release cycle.
>
> Reviewed-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>

Thanks!

If GregKH provides his ack, Rafael can take it with your named genpd API
removal series? Shall I resend with an official request?

> Kind regards
> Uffe
>
>> ---
>> drivers/staging/board/armadillo800eva.c | 2 +-
>> drivers/staging/board/board.c | 36 ++++++++++++++++++++++++++++++++-
>> 2 files changed, 36 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/staging/board/armadillo800eva.c b/drivers/staging/board/armadillo800eva.c
>> index 0165591a52443c46..912c96b0536def7c 100644
>> --- a/drivers/staging/board/armadillo800eva.c
>> +++ b/drivers/staging/board/armadillo800eva.c
>> @@ -91,7 +91,7 @@ static const struct board_staging_dev armadillo800eva_devices[] __initconst = {
>> .pdev = &lcdc0_device,
>> .clocks = lcdc0_clocks,
>> .nclocks = ARRAY_SIZE(lcdc0_clocks),
>> - .domain = "a4lc",
>> + .domain = "/system-controller@e6180000/pm-domains/c5/a4lc@1"
>> },
>> };
>>
>> diff --git a/drivers/staging/board/board.c b/drivers/staging/board/board.c
>> index 29d456e29f38feac..3eb5eb8f069c236d 100644
>> --- a/drivers/staging/board/board.c
>> +++ b/drivers/staging/board/board.c
>> @@ -135,6 +135,40 @@ int __init board_staging_register_clock(const struct board_staging_clk *bsc)
>> return error;
>> }
>>
>> +#ifdef CONFIG_PM_GENERIC_DOMAINS_OF
>> +static int board_staging_add_dev_domain(struct platform_device *pdev,
>> + const char *domain)
>> +{
>> + struct of_phandle_args pd_args;
>> + struct generic_pm_domain *pd;
>> + struct device_node *np;
>> +
>> + np = of_find_node_by_path(domain);
>> + if (!np) {
>> + pr_err("Cannot find domain node %s\n", domain);
>> + return -ENOENT;
>> + }
>> +
>> + pd_args.np = np;
>> + pd_args.args_count = 0;
>> + pd = of_genpd_get_from_provider(&pd_args);
>> + if (IS_ERR(pd)) {
>> + pr_err("Cannot find genpd %s (%ld)\n", domain, PTR_ERR(pd));
>> + return PTR_ERR(pd);
>> +
>> + }
>> + pr_debug("Found genpd %s for device %s\n", pd->name, pdev->name);
>> +
>> + return pm_genpd_add_device(pd, &pdev->dev);
>> +}
>> +#else
>> +static inline int board_staging_add_dev_domain(struct platform_device *pdev,
>> + const char *domain)
>> +{
>> + return 0;
>> +}
>> +#endif
>> +
>> int __init board_staging_register_device(const struct board_staging_dev *dev)
>> {
>> struct platform_device *pdev = dev->pdev;
>> @@ -161,7 +195,7 @@ int __init board_staging_register_device(const struct board_staging_dev *dev)
>> }
>>
>> if (dev->domain)
>> - __pm_genpd_name_add_device(dev->domain, &pdev->dev, NULL);
>> + board_staging_add_dev_domain(pdev, dev->domain);
>>
>> return error;
>> }
>> --
>> 1.9.1

Gr{oetje,eeting}s,

Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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