Re: [PATCH PM-0] ARM: OMAP3: HSMMC: Ensure HSMMC is fully reset on boot

[Kevin Hilman <khilman@deeprootsystems.com>]

"Madhusudhan Chikkature" <madhu.cr@ti.com> writes:

> ----- Original Message ----- 
> From: "Kevin Hilman" <khilman@deeprootsystems.com>
> To: <linux-omap@vger.kernel.org>
> Cc: "Kevin Hilman" <khilman@deeprootsystems.com>
> Sent: Thursday, September 18, 2008 5:52 PM
> Subject: [PATCH PM-0] ARM: OMAP3: HSMMC: Ensure HSMMC is fully reset on boot
>
>
>> This ensures that an unused HSMMC block will not interfere with sleep.
>> 
>> Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
>> ---
>> arch/arm/mach-omap2/hsmmc.c |    8 ++++++++
>> 1 files changed, 8 insertions(+), 0 deletions(-)
>> 
>> diff --git a/arch/arm/mach-omap2/hsmmc.c b/arch/arm/mach-omap2/hsmmc.c
>> index 7334d86..03fe820 100644
>> --- a/arch/arm/mach-omap2/hsmmc.c
>> +++ b/arch/arm/mach-omap2/hsmmc.c
>> @@ -280,8 +280,16 @@ static struct omap_mmc_platform_data hsmmc_data = {
>>  },
>> };
>> 
>> +static void __init hsmmc_reset(void)
>> +{
>> +       omap_writel(MMCHS_SYSCONFIG_SWRESET, MMCHS1_SYSCONFIG);
>> +       omap_writel(MMCHS_SYSCONFIG_SWRESET, MMCHS2_SYSCONFIG);
>> +       omap_writel(MMCHS_SYSCONFIG_SWRESET, MMCHS3_SYSCONFIG);
>> +}
>> +
> Where is MMCHS1_SYSCONFIG defined?

Oops, I sent this prematurely, indeed it doesn't compile. :(

> After seting the softreset bit in SYSCONFIG, you might want to poll
> on the RESETDONE bit in SYSSTATUS to wait for the reset to complete.

OK, I'll add that.

> The interface and functional clocks should be provided before the
> reset is issued for reset to complete. At this point, I guess the
> clocks are not enabled yet.

They're not enabled by the kernel, but I believe they are enabled by
the bootloader.  Are you suggesting I add explicit clk_enable|disable
calls?

Kevin