[PATCH] ARM: SAMSUNG: Add support for clock debugging through debug-fs interface

Yong Shen yong.shen at linaro.org
Tue Nov 16 21:03:33 EST 2010


In that case, please see my few comments inline.

Yong

On Tue, Nov 16, 2010 at 8:40 PM, Amit Kucheria <amit.kucheria at linaro.org>wrote:

> Yong,
>
> No. The work that you're doing is long-term. It will take time for
> platforms
> to move to the common struct clk - almost unlikely for the next Linaro
> release.
>
> In the short-term, we still need all partner platforms to expose this debug
> information for our tools in a consistent way - OMAP already does it this
> way.  So we want this patch applied to the Samsung platform after review
> and
> similar ones for other SoC kernels.
>
> /Amit
>
> On 10 Nov 16, Yong Shen wrote:
> > Hi Amit,
> >
> > We are trying to make this clock debug interface generic, so every
> platform
> > can benefit from it. Maybe it is better to wait for a while until the
> common
> > interface comes out.
> >
> > Yong
> >
> > On Tue, Nov 16, 2010 at 6:54 PM, <amit.daniel at samsung.com> wrote:
> >
> > > From: Amit Daniel Kachhap <amit.daniel at samsung.com>
> > >
> > > This patch adds support for clock information exposed to debug-fs
> > > interface.
> > >
> > > Signed-off-by: Amit Daniel Kachhap <amit.daniel at samsung.com>
> > > ---
> > >  arch/arm/plat-samsung/clock.c              |   92
> > > ++++++++++++++++++++++++++++
> > >  arch/arm/plat-samsung/include/plat/clock.h |    3 +
> > >  2 files changed, 95 insertions(+), 0 deletions(-)
> > >
> > > diff --git a/arch/arm/plat-samsung/clock.c
> b/arch/arm/plat-samsung/clock.c
> > > index e8d20b0..0ba209d 100644
> > > --- a/arch/arm/plat-samsung/clock.c
> > > +++ b/arch/arm/plat-samsung/clock.c
> > > @@ -39,6 +39,7 @@
> > >  #include <linux/clk.h>
> > >  #include <linux/spinlock.h>
> > >  #include <linux/io.h>
> > > +#include <linux/debugfs.h>
>
Also enclose this head in macro  CONFIG_DEBUG_FS
And you may also want to use CONFIG_PM_DEBUG combined with CONFIG_DEBUG_FS,
and this may apply to below cases.

> > >
> > >  #include <mach/hardware.h>
> > >  #include <asm/irq.h>
> > > @@ -447,3 +448,94 @@ int __init s3c24xx_register_baseclocks(unsigned
> long
> > > xtal)
> > >        return 0;
> > >  }
> > >
> > > +#if defined(CONFIG_DEBUG_FS)
>
> > +/*
> > > + *     debugfs support to trace clock tree hierarchy and attributes
> > > + */
> > > +static struct dentry *clk_debugfs_root;
> > > +
> > > +static int clk_debugfs_register_one(struct clk *c)
> > > +{
> > > +       int err;
> > > +       struct dentry *d, *child, *child_tmp;
> > > +       struct clk *pa = c->parent;
> > > +       char s[255];
> > > +       char *p = s;
> > > +
> > > +       p += sprintf(p, "%s", c->name);
> > > +#ifdef CONFIG_PLAT_SAMSUNG
> > > +       /*Append id field with name also*/
> > > +       if (c->id >= 0)
> > > +               p += sprintf(p, ":%d", c->id);
> > > +#endif
> > > +
> > > +       d = debugfs_create_dir(s, pa ? pa->dent : clk_debugfs_root);
> > > +       if (!d)
> > > +               return -ENOMEM;
> > > +
> > > +       c->dent = d;
> > > +
> > > +       d = debugfs_create_u8("usecount", S_IRUGO, c->dent, (u8
> > > *)&c->usage);
> > > +       if (!d) {
> > > +               err = -ENOMEM;
> > > +               goto err_out;
> > > +       }
> > > +       d = debugfs_create_u32("rate", S_IRUGO, c->dent, (u32
> *)&c->rate);
> > > +       if (!d) {
> > > +               err = -ENOMEM;
> > > +               goto err_out;
> > > +       }
> > > +       return 0;
> > > +
> > > +err_out:
> > > +       d = c->dent;
> > > +       list_for_each_entry_safe(child, child_tmp, &d->d_subdirs,
> > > d_u.d_child)
> > > +               debugfs_remove(child);
> > > +       debugfs_remove(c->dent);
> > > +       return err;
> > > +}
> > > +
> > > +static int clk_debugfs_register(struct clk *c)
> > > +{
> > > +       int err;
> > > +       struct clk *pa = c->parent;
> > > +
> > > +       if (pa && !pa->dent) {
> > > +               err = clk_debugfs_register(pa);
> > > +               if (err)
> > > +                       return err;
> > > +       }
> > > +
> > > +       if (!c->dent) {
> > > +               err = clk_debugfs_register_one(c);
> > > +               if (err)
> > > +                       return err;
> > > +       }
> > > +       return 0;
> > > +}
> > > +
> > > +static int __init clk_debugfs_init(void)
> > > +{
> > > +       struct clk *c;
> > > +       struct dentry *d;
> > > +       int err;
> > > +
> > > +       d = debugfs_create_dir("clock", NULL);
> > > +       if (!d)
> > > +               return -ENOMEM;
> > > +       clk_debugfs_root = d;
> > > +
> > > +       list_for_each_entry(c, &clocks, list) {
> > > +               err = clk_debugfs_register(c);
> > > +               if (err)
> > > +                       goto err_out;
> > > +       }
> > > +       return 0;
> > > +err_out:
> > > +       debugfs_remove_recursive(clk_debugfs_root);
> > > +       return err;
> > > +}
> > > +late_initcall(clk_debugfs_init);
> > > +
> > > +#endif /* defined(CONFIG_DEBUG_FS) */
> > > +
> > > diff --git a/arch/arm/plat-samsung/include/plat/clock.h
> > > b/arch/arm/plat-samsung/include/plat/clock.h
> > > index 0fbcd0e..f6180ab 100644
> > > --- a/arch/arm/plat-samsung/include/plat/clock.h
> > > +++ b/arch/arm/plat-samsung/include/plat/clock.h
> > > @@ -47,6 +47,9 @@ struct clk {
> > >
> > >        struct clk_ops          *ops;
> > >        int                 (*enable)(struct clk *, int enable);
> > > +#if defined(CONFIG_DEBUG_FS)
> > > +       struct dentry           *dent;  /* For visible tree hierarchy
> */
> > > +#endif
> > >  };
> > >
> > >  /* other clocks which may be registered by board support */
> > > --
> > > 1.6.0.6
> > >
> > >
> > > _______________________________________________
> > > linaro-dev mailing list
> > > linaro-dev at lists.linaro.org
> > > http://lists.linaro.org/mailman/listinfo/linaro-dev
> > >
>
> > _______________________________________________
> > linaro-dev mailing list
> > linaro-dev at lists.linaro.org
> > http://lists.linaro.org/mailman/listinfo/linaro-dev
>
>
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