Re: [RFC 08/15] clk: add restrack support

[Mike Turquette <mturquette-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>]

+Stephen Boyd

Quoting Andrzej Hajda (2014-12-10 07:48:26)
> Clocks supports different methods of lookup.
> The patch adds restrack support only to DT based clocks.
> 
> Signed-off-by: Andrzej Hajda <a.hajda-Sze3O3UU22JBDgjK7y7TUQ@public.gmane.org>
> ---
>  drivers/clk/clk.c        |  6 ++++
>  drivers/clk/clkdev.c     | 74 ++++++++++++++++++++++++++++++++++++++++++++++++
>  include/linux/clk.h      |  3 ++
>  include/linux/restrack.h |  1 +
>  4 files changed, 84 insertions(+)
> 
> diff --git a/drivers/clk/clk.c b/drivers/clk/clk.c
> index 4896ae9..2c50204 100644
> --- a/drivers/clk/clk.c
> +++ b/drivers/clk/clk.c
> @@ -16,6 +16,7 @@
>  #include <linux/spinlock.h>
>  #include <linux/err.h>
>  #include <linux/list.h>
> +#include <linux/restrack.h>
>  #include <linux/slab.h>
>  #include <linux/of.h>
>  #include <linux/device.h>
> @@ -2476,6 +2477,9 @@ int of_clk_add_provider(struct device_node *np,
>         ret = of_clk_set_defaults(np, true);
>         if (ret < 0)
>                 of_clk_del_provider(np);
> +       else
> +               restrack_up(RESTRACK_TYPE_CLOCK, cp->node, cp);
> +
>  
>         return ret;
>  }
> @@ -2489,6 +2493,8 @@ void of_clk_del_provider(struct device_node *np)
>  {
>         struct of_clk_provider *cp;
>  
> +       restrack_down(RESTRACK_TYPE_CLOCK, np, NULL);
> +
>         mutex_lock(&of_clk_mutex);
>         list_for_each_entry(cp, &of_clk_providers, link) {
>                 if (cp->node == np) {
> diff --git a/drivers/clk/clkdev.c b/drivers/clk/clkdev.c
> index bd22750..2532ea1 100644
> --- a/drivers/clk/clkdev.c
> +++ b/drivers/clk/clkdev.c
> @@ -20,6 +20,7 @@
>  #include <linux/clk.h>
>  #include <linux/clkdev.h>
>  #include <linux/of.h>
> +#include <linux/restrack.h>
>  
>  #include "clk.h"
>  
> @@ -143,6 +144,79 @@ static int of_get_clock_spec(struct device *dev, const char *name,
>  
>         return -ENOENT;
>  }
> +
> +struct clk_restrack_desc {
> +       struct clk **ptr;
> +       const char *name;
> +       struct of_phandle_args spec;
> +       struct restrack_desc desc;
> +};
> +
> +static int clk_restrack_init(struct device *dev,
> +               struct restrack_desc *desc)
> +{
> +       struct clk_restrack_desc *rd = restrack_desc_to_rd(rd, desc);
> +       int ret;
> +
> +       ret = of_get_clock_spec(dev, rd->name, &rd->spec);
> +       if (!ret)
> +               desc->if_id = rd->spec.np;
> +       return ret;
> +}
> +
> +static void clk_restrack_destroy(struct device *dev,
> +               struct restrack_desc *desc)
> +{
> +       struct clk_restrack_desc *rd = restrack_desc_to_rd(rd, desc);
> +
> +       of_node_put(desc->if_id);
> +       kfree(rd);
> +}
> +
> +static int clk_restrack_ifup(struct device *dev,
> +               struct restrack_desc *desc, void *data)
> +{
> +       struct clk_restrack_desc *rd = restrack_desc_to_rd(rd, desc);
> +
> +       *rd->ptr = of_clk_get_by_clkspec(&rd->spec);
> +       return PTR_ERR_OR_ZERO(*rd->ptr);
> +}
> +
> +static void clk_restrack_ifdown(struct device *dev,
> +               struct restrack_desc *desc, void *data)
> +{
> +       struct clk_restrack_desc *rd = restrack_desc_to_rd(rd, desc);
> +
> +       clk_put(*rd->ptr);
> +       *rd->ptr = ERR_PTR(-EPROBE_DEFER);
> +}
> +
> +static const struct restrack_ops clk_restrack_ops = {
> +       .if_type = RESTRACK_TYPE_CLOCK,
> +       .init = clk_restrack_init,
> +       .destroy = clk_restrack_destroy,
> +       .if_up = clk_restrack_ifup,
> +       .if_down = clk_restrack_ifdown,
> +};
> +
> +/**
> + * clk_restrack_desc - clock resource descriptor allocator
> + * @clk: pointer to variable which will be set to clock handle
> + * @name: name of clock
> + *
> + * The function creates resource description for clock, which shall be used
> + * by *restrack_register functions.
> + */
> +struct restrack_desc *clk_restrack_desc(struct clk **clock, const char *name)
> +{
> +       struct clk_restrack_desc *rd;
> +
> +       RESTRACK_DESC_ALLOC(rd, clk_restrack_ops, clock, name);
> +
> +       return rd ? &rd->desc : ERR_PTR(-ENOMEM);
> +}
> +EXPORT_SYMBOL_GPL(clk_restrack_desc);
> +
>  #endif
>  
>  /*
> diff --git a/include/linux/clk.h b/include/linux/clk.h
> index c7f258a..28bad95 100644
> --- a/include/linux/clk.h
> +++ b/include/linux/clk.h
> @@ -428,6 +428,9 @@ struct of_phandle_args;
>  struct clk *of_clk_get(struct device_node *np, int index);
>  struct clk *of_clk_get_by_name(struct device_node *np, const char *name);
>  struct clk *of_clk_get_from_provider(struct of_phandle_args *clkspec);
> +
> +struct restrack_desc;
> +struct restrack_desc *clk_restrack_desc(struct clk **clock, const char *name);
>  #else
>  static inline struct clk *of_clk_get(struct device_node *np, int index)
>  {
> diff --git a/include/linux/restrack.h b/include/linux/restrack.h
> index e1aded0..6707dce 100644
> --- a/include/linux/restrack.h
> +++ b/include/linux/restrack.h
> @@ -6,6 +6,7 @@
>  #define RESTRACK_TYPE_DRM_PANEL 1
>  #define RESTRACK_TYPE_REGULATOR 2
>  #define RESTRACK_TYPE_GPIO 3
> +#define RESTRACK_TYPE_CLOCK 4
>  
>  struct device;
>  struct restrack_ctx;
> -- 
> 1.9.1
> 
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