Kyungmin Park wrote:
> Hi,
>
> On Mon, Feb 23, 2009 at 5:04 PM, Adrian Hunter
> <ext-adrian.hunter@xxxxxxxxx> wrote:
>> ext Kim Kyuwon wrote:
>>> Hi,
>>>
>>> On Sat, Feb 21, 2009 at 6:11 AM, David Brownell <david-b@xxxxxxxxxxx> wrote:
>>>> On Friday 20 February 2009, Kim Kyuwon wrote:
>>>>> +static void omap_hsmmc_init(struct mmc_omap_host *host)
>>>>> +{
>>>>> + u32 hctl, capa, value;
>>>>> +
>>>>> + /* Only MMC1 supports 3.0V */
>>>>> + if (host->id == OMAP_MMC1_DEVID) {
>>>>> + hctl = SDVS30;
>>>> Shouldn't it be remembering what voltage it was using,
>>>> and then restore that, instead of always making MMC1
>>>> restart at a 3.0V level? That's pretty awkward to test
>>>> unless you have a 1.8V-capable card in MMC1...
>>> You are somewhat right, thank you.
>>> But remebering what voltage it was using doesn't feasible to me,
>>> because the card can be changed while in 'Sleep' state. I should have
>>> inserted a function that detect the right voltage after intializing. I
>>> will resend the patch later.
>> Doesn't it already do that? Can you explain more?
>>
>> Although I have not tested it, I very much doubt
>> dual-voltage cards work. That is because VMMC1_185V
>> is zero, which has the side-effect of turning the
>> regulator off (see arch/arm/mach-omap2/mmc-twl4030.c)
>
> It's also to difficult to test in our H/W since it's configured only
> support 3.0V.
>
> How about to separate it two phases, first fix the mmc suspend/resume
> works again, and then verify dual voltage if there are these hardware
>
> How to you think?
Yes certainly.
The original code assumes that 'host' may be NULL in omap_mmc_suspend ()
and omap_mmc_resume(), whereas the patch assumes 'host' is never NULL.
I suggest:
static int omap_mmc_suspend(struct platform_device *pdev, pm_message_t state)
{
int ret = 0;
struct mmc_omap_host *host = platform_get_drvdata(pdev);
- if (host && host->suspended)
+ if (!host || host->suspended)
return 0;
and
static int omap_mmc_resume(struct platform_device *pdev)
{
int ret = 0;
struct mmc_omap_host *host = platform_get_drvdata(pdev);
- if (host && !host->suspended)
+ if (!host || !host->suspended)
return 0;
Also the patch does not wait for the bus voltage (SDBP bit) to
initialise. For the sake of correctness, I would add something
like:
OMAP_HSMMC_WRITE(host->base, HCTL, value | SDBP);
+ for (i = 0; i < loops_per_jiffy; i++) {
+ if (OMAP_HSMMC_READ(host->base, HCTL) & SDBP)
+ break;
+ cpu_relax();
+ }
Also, you will need the following patch if you actually want the power
to go off.
From: Adrian Hunter <ext-adrian.hunter@xxxxxxxxx>
Date: Fri, 30 Jan 2009 11:58:13 +0200
Subject: [PATCH] OMAP: HSMMC: do not power up after powering off
The power is configured when probing and when resuming
so the bus voltage does not need changing after power
off.
Signed-off-by: Adrian Hunter <ext-adrian.hunter@xxxxxxxxx>
---
drivers/mmc/host/omap_hsmmc.c | 10 ----------
1 files changed, 0 insertions(+), 10 deletions(-)
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 1e4a2e0..04e5a0c 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -859,16 +859,6 @@ static void omap_mmc_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
switch (ios->power_mode) {
case MMC_POWER_OFF:
mmc_slot(host).set_power(host->dev, host->slot_id, 0, 0);
- /*
- * Reset bus voltage to 3V if it got set to 1.8V earlier.
- * REVISIT: If we are able to detect cards after unplugging
- * a 1.8V card, this code should not be needed.
- */
- if (!(OMAP_HSMMC_READ(host->base, HCTL) & SDVSDET)) {
- int vdd = fls(host->mmc->ocr_avail) - 1;
- if (omap_mmc_switch_opcond(host, vdd) != 0)
- host->mmc->ios.vdd = vdd;
- }
break;
case MMC_POWER_UP:
mmc_slot(host).set_power(host->dev, host->slot_id, 1, ios->vdd);
--
1.5.4.3
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