Hi Benoit,
one minor comment here -
On Tue, 21 Sep 2010, Benoit Cousson wrote:
> Some modules (like GPIO, DSS...) require optionals clock to be enabled
> in order to complete the sofreset properly.
> Add a HWMOD_CONTROL_OPT_CLKS_IN_RESET flag to force all optional clocks
> to be enabled before reset. Disabled them once the reset is done.
>
> TODO:
> For the moment it is very hard to understand from the HW spec, which
> optional clock is needed and which one is not. So the current approach
> will enable all the optional clocks.
> Paul proposed a much finer approach that will allow to tag only the needed
> clock in the optional clock table. This might be doable as soon as we have
> a clear understanding of these dependencies.
>
> Reported-by: Partha Basak <p-basak2@xxxxxx>
> Signed-off-by: Benoit Cousson <b-cousson@xxxxxx>
> Cc: Paul Walmsley <paul@xxxxxxxxx>
> Cc: Kevin Hilman <khilman@xxxxxxxxxxxxxxxxxxx>
> ---
> arch/arm/mach-omap2/omap_hwmod.c | 51 +++++++++++++++++++++++---
> arch/arm/plat-omap/include/plat/omap_hwmod.h | 5 +++
> 2 files changed, 51 insertions(+), 5 deletions(-)
>
> diff --git a/arch/arm/mach-omap2/omap_hwmod.c b/arch/arm/mach-omap2/omap_hwmod.c
> index 8c27923..4309107 100644
> --- a/arch/arm/mach-omap2/omap_hwmod.c
> +++ b/arch/arm/mach-omap2/omap_hwmod.c
> @@ -546,6 +546,36 @@ static int _disable_clocks(struct omap_hwmod *oh)
> return 0;
> }
>
> +static void _enable_optional_clocks(struct omap_hwmod *oh)
> +{
> + struct omap_hwmod_opt_clk *oc;
> + int i;
> +
> + pr_debug("omap_hwmod: %s: enabling optional clocks\n", oh->name);
> +
> + for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i > 0; i--, oc++)
> + if (oc->_clk) {
> + pr_warning("omap_hwmod: enable %s:%s\n", oc->role,
> + oc->_clk->name);
What do you think about maybe converting this to a pr_debug() (and the
same in the disable code below)? If you are happy with that, I can make
the change here when I pull the patch in.
> + clk_enable(oc->_clk);
> + }
> +}
> +
> +static void _disable_optional_clocks(struct omap_hwmod *oh)
> +{
> + struct omap_hwmod_opt_clk *oc;
> + int i;
> +
> + pr_debug("omap_hwmod: %s: disabling optional clocks\n", oh->name);
> +
> + for (i = oh->opt_clks_cnt, oc = oh->opt_clks; i > 0; i--, oc++)
> + if (oc->_clk) {
> + pr_warning("omap_hwmod: disable %s:%s\n", oc->role,
> + oc->_clk->name);
> + clk_disable(oc->_clk);
> + }
> +}
> +
> /**
> * _find_mpu_port_index - find hwmod OCP slave port ID intended for MPU use
> * @oh: struct omap_hwmod *
> @@ -970,8 +1000,9 @@ static int _read_hardreset(struct omap_hwmod *oh, const char *name)
> */
> static int _reset(struct omap_hwmod *oh)
> {
> - u32 r, v;
> + u32 v;
> int c = 0;
> + int ret = 0;
>
> if (!oh->class->sysc ||
> !(oh->class->sysc->sysc_flags & SYSC_HAS_SOFTRESET) ||
> @@ -985,12 +1016,16 @@ static int _reset(struct omap_hwmod *oh)
> return -EINVAL;
> }
>
> + /* For some modules, all optionnal clocks need to be enabled as well */
> + if (oh->flags & HWMOD_CONTROL_OPT_CLKS_IN_RESET)
> + _enable_optional_clocks(oh);
> +
> pr_debug("omap_hwmod: %s: resetting\n", oh->name);
>
> v = oh->_sysc_cache;
> - r = _set_softreset(oh, &v);
> - if (r)
> - return r;
> + ret = _set_softreset(oh, &v);
> + if (ret)
> + goto dis_opt_clks;
> _write_sysconfig(v, oh);
>
> omap_test_timeout((omap_hwmod_readl(oh, oh->class->sysc->syss_offs) &
> @@ -1008,7 +1043,13 @@ static int _reset(struct omap_hwmod *oh)
> * _wait_target_ready() or _reset()
> */
>
> - return (c == MAX_MODULE_SOFTRESET_WAIT) ? -ETIMEDOUT : 0;
> + ret = (c == MAX_MODULE_SOFTRESET_WAIT) ? -ETIMEDOUT : 0;
> +
> +dis_opt_clks:
> + if (oh->flags & HWMOD_CONTROL_OPT_CLKS_IN_RESET)
> + _disable_optional_clocks(oh);
> +
> + return ret;
> }
>
> /**
> diff --git a/arch/arm/plat-omap/include/plat/omap_hwmod.h b/arch/arm/plat-omap/include/plat/omap_hwmod.h
> index 7fde44d..878f919 100644
> --- a/arch/arm/plat-omap/include/plat/omap_hwmod.h
> +++ b/arch/arm/plat-omap/include/plat/omap_hwmod.h
> @@ -368,6 +368,10 @@ struct omap_hwmod_omap4_prcm {
> * HWMOD_SET_DEFAULT_CLOCKACT: program CLOCKACTIVITY bits at startup
> * HWMOD_NO_IDLEST : this module does not have idle status - this is the case
> * only for few initiator modules on OMAP2 & 3.
> + * HWMOD_CONTROL_OPT_CLKS_IN_RESET: Enable all optional clocks during reset.
> + * This is needed for devices like DSS that require optional clocks enabled
> + * in order to complete the reset. Optional clocks will be disabled
> + * again after the reset.
> */
> #define HWMOD_SWSUP_SIDLE (1 << 0)
> #define HWMOD_SWSUP_MSTANDBY (1 << 1)
> @@ -376,6 +380,7 @@ struct omap_hwmod_omap4_prcm {
> #define HWMOD_NO_OCP_AUTOIDLE (1 << 4)
> #define HWMOD_SET_DEFAULT_CLOCKACT (1 << 5)
> #define HWMOD_NO_IDLEST (1 << 6)
> +#define HWMOD_CONTROL_OPT_CLKS_IN_RESET (1 << 7)
>
> /*
> * omap_hwmod._int_flags definitions
> --
> 1.6.0.4
>
- Paul
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