Re: MMC_CAP_SDIO_IRQ for omap 3430

[Dirk Behme <dirk.behme@googlemail.com>]

John,

John Rigby wrote:
> Dirk,
> 
> Many thanks, after sending the request yesterday I made my own attempt
> which failed miserably.  My patch looks like a subset of yours so that
> is to be expected.  I'll try yours out today and report back my
> experience.

I got already some (private) feedback (thanks!):

- Accessing host->mmc->card in omap_hsmmc_set_ios() results in a null 
pointer :( Seems that mmc->card isn't set yet while calling 
omap_hsmmc_set_ios().

As workaround, for testing only, I hard coded setting IBG with 
something like

         case MMC_BUS_WIDTH_4:
                 OMAP_HSMMC_WRITE(host->base, CON, con & ~DW8);
-               OMAP_HSMMC_WRITE(host->base, HCTL,
-                       OMAP_HSMMC_READ(host->base, HCTL) | FOUR_BIT);
+                       OMAP_HSMMC_WRITE(host->base, HCTL,
+                                        OMAP_HSMMC_READ(host->base, 
HCTL) | IBG | FOUR_BIT);
                break;

If you test this, be careful that this doesn't hurt any other 4 bit 
cards except the SDIO you want to test.

Later, we have to find a way how to detect that we are in SDIO mode. 
We want to set IBG only if in SDIO and 4 bit mode.

-  After this, I got the report that null pointer crash is gone. But 
SDIO doesn't seem to work any more:

libertas_sdio: Libertas SDIO driver
libertas_sdio: Copyright Pierre Ossman
libertas_sdio mmc1:0001:1: firmware: requesting sd8686_helper.bin
libertas_sdio mmc1:0001:1: firmware: requesting sd8686.bin
libertas: command 0x0003 timed out
libertas: requeueing command 0x0003 due to timeout (#1)
libertas: command 0x0003 timed out
libertas: requeueing command 0x0003 due to timeout (#2)
libertas: command 0x0003 timed out
libertas: requeueing command 0x0003 due to timeout (#3)
libertas: command 0x0003 timed out
libertas: Excessive timeouts submitting command 0x0003
libertas: PREP_CMD: command 0x0003 failed: -110
libertas_sdio: probe of mmc1:0001:1 failed with error -110

I now start to think about it ;)

Again, any help would be appreciated!

Best regards

Dirk

> On Fri, Oct 16, 2009 at 1:16 AM, Dirk Behme <dirk.behme@googlemail.com> wrote:
>> John Rigby wrote:
>>> I have seen several discussions about lack of sdio irq support in the
>>> hsmmc driver but no patches.  Has anyone on this list implemented this
>>> and/or can anyone point me to patches?
>> What a coincidence ;)
>>
>> I'm currently working on this. See attachment what I currently have. It is
>> compile tested only against recent omap linux head. I don't have a board
>> using SDIO at the moment, so no real testing possible :(
>>
>> Some background, maybe it helps people to step in:
>>
>> Gumstix OMAP3 based Overo air board connects Marvell 88W8686 wifi by MMC
>> port 2 in 4 bit configuration [1]. The wifi performance is quite bad
>> (~100kB/s). There is some rumor that this might be SDIO irq related [2].
>> There was an attempt to fix this [3] already, but this doesn't work [4].
>> Having this, I started to look into it.
>>
>> I used [3], the TI Davinci driver [5] (supporting SDIO irq), the SDIO
>> Simplified Specification [6] and the OMAP35x TRM [7] as starting points.
>>
>> Unfortunately, the Davinci MMC registers and irqs are different (Davinci has
>> a dedicated SDIO irq). But combining [3] and [5] helps to get an idea what
>> has to be done.
>>
>> I think the main issues of [3] were that it doesn't enable IBG for 4 bit
>> mode ([6] chapter 8.1.2) and that mmc_omap_irq() doesn't reset the irq bits.
>>
>> Topics I still open:
>>
>> - Is it always necessary to deal with IE _and_ ISE register? I'm not totally
>> clear what the difference between these two registers are ;) And in which
>> order they have to be set.
>>
>> - Davinci driver [5] in line 1115 checks for data line to call
>> mmc_signal_sdio_irq() for irq enable.
>>
>> - Davinci driver deals with SDIO in xfer_done() (line 873)
>>
>> - Davinci driver sets block size to 64 if SDIO in line 701
>>
>> It would be quite nice if anybody likes to comment on attachment and help
>> testing.
>>
>> Many thanks and best regards
>>
>> Dirk
>>
>> [1] http://gumstix.net/wiki/index.php?title=Overo_Wifi
>>
>> [2] http://groups.google.com/group/beagleboard/msg/14e822778c5eeb56
>>
>> [3] http://groups.google.com/group/beagleboard/msg/d0eb69f4c20673be
>>
>> [4] http://groups.google.com/group/beagleboard/msg/5cdfe2a319531937
>>
>> [5]
>> http://arago-project.org/git/projects/?p=linux-davinci.git;a=blob;f=drivers/mmc/host/davinci_mmc.c;h=1bf0587250614c6d8abfe02028b96e0e47148ac8;hb=HEAD
>>
>> [6] http://www.sdcard.org/developers/tech/sdio/sd_bluetooth_spec/
>>
>> [7] http://focus.ti.com/lit/ug/spruf98c/spruf98c.pdf
>>
>>
>> Subject: [PATCH][RFC] OMAP HSMMC: Add SDIO interrupt support
>> Form: Dirk Behme <dirk.behme@googlemail.com>
>>
>> At the moment, OMAP HSMMC driver supports only SDIO polling, resulting in
>> poor
>> performance. Add support for SDIO interrupt handling.
>>
>> Signed-off-by: Dirk Behme <dirk.behme@googlemail.com>
>> ---
>>
>> Patch against recent omap-linux head "Linux omap got rebuilt from scratch"
>> 274c94b29ee7c53609a756acca974e4742c59559
>>
>> Compile tested only. Please comment and help testing.
>>
>>  drivers/mmc/host/omap_hsmmc.c |   48
>> +++++++++++++++++++++++++++++++++++++-----
>>  1 file changed, 43 insertions(+), 5 deletions(-)
>>
>> Index: linux-beagle/drivers/mmc/host/omap_hsmmc.c
>> ===================================================================
>> --- linux-beagle.orig/drivers/mmc/host/omap_hsmmc.c
>> +++ linux-beagle/drivers/mmc/host/omap_hsmmc.c
>> @@ -27,6 +27,7 @@
>>  #include <linux/timer.h>
>>  #include <linux/clk.h>
>>  #include <linux/mmc/host.h>
>> +#include <linux/mmc/card.h>
>>  #include <linux/mmc/core.h>
>>  #include <linux/io.h>
>>  #include <linux/semaphore.h>
>> @@ -65,6 +66,7 @@
>>  #define SDVSDET                        0x00000400
>>  #define AUTOIDLE               0x1
>>  #define SDBP                   (1 << 8)
>> +#define IBG                    (1 << 19)
>>  #define DTO                    0xe
>>  #define ICE                    0x1
>>  #define ICS                    0x2
>> @@ -76,6 +78,7 @@
>>  #define INT_EN_MASK            0x307F0033
>>  #define BWR_ENABLE             (1 << 4)
>>  #define BRR_ENABLE             (1 << 5)
>> +#define CIRQ_ENABLE            (1 << 8)
>>  #define INIT_STREAM            (1 << 1)
>>  #define DP_SELECT              (1 << 21)
>>  #define DDIR                   (1 << 4)
>> @@ -87,6 +90,7 @@
>>  #define CC                     0x1
>>  #define TC                     0x02
>>  #define OD                     0x1
>> +#define CIRQ                   (1 <<  8)
>>  #define ERR                    (1 << 15)
>>  #define CMD_TIMEOUT            (1 << 16)
>>  #define DATA_TIMEOUT           (1 << 20)
>> @@ -653,6 +657,15 @@ static irqreturn_t omap_hsmmc_irq(int ir
>>        status = OMAP_HSMMC_READ(host->base, STAT);
>>        dev_dbg(mmc_dev(host->mmc), "IRQ Status is %x\n", status);
>>
>> +       if (status & CIRQ) {
>> +               dev_dbg(mmc_dev(host->mmc), "SDIO interrupt");
>> +               OMAP_HSMMC_WRITE(host->base, IE, OMAP_HSMMC_READ(host->base,
>> IE)
>> +                                & ~(CIRQ_ENABLE));
>> +               mmc_signal_sdio_irq(host->mmc);
>> +               spin_unlock(&host->irq_lock);
>> +               return IRQ_HANDLED;
>> +       }
>> +
>>        if (status & ERR) {
>>  #ifdef CONFIG_MMC_DEBUG
>>                omap_hsmmc_report_irq(host, status);
>> @@ -1165,8 +1178,15 @@ static void omap_hsmmc_set_ios(struct mm
>>                break;
>>        case MMC_BUS_WIDTH_4:
>>                OMAP_HSMMC_WRITE(host->base, CON, con & ~DW8);
>> -               OMAP_HSMMC_WRITE(host->base, HCTL,
>> -                       OMAP_HSMMC_READ(host->base, HCTL) | FOUR_BIT);
>> +               if (mmc_card_sdio(host->mmc->card)) {
>> +                       OMAP_HSMMC_WRITE(host->base, HCTL,
>> +                                        OMAP_HSMMC_READ(host->base, HCTL)
>> +                                        | IBG | FOUR_BIT);
>> +               } else {
>> +                       OMAP_HSMMC_WRITE(host->base, HCTL,
>> +                                        OMAP_HSMMC_READ(host->base, HCTL)
>> +                                        | FOUR_BIT);
>> +               }
>>                break;
>>        case MMC_BUS_WIDTH_1:
>>                OMAP_HSMMC_WRITE(host->base, CON, con & ~DW8);
>> @@ -1512,6 +1532,24 @@ static int omap_hsmmc_disable_fclk(struc
>>        return 0;
>>  }
>>
>> +static void omap_hsmmc_enable_sdio_irq(struct mmc_host *mmc, int enable)
>> +{
>> +       struct omap_hsmmc_host *host = mmc_priv(mmc);
>> +       u32 ie, ise;
>> +
>> +       ise = OMAP_HSMMC_READ(host->base, ISE);
>> +       ie  = OMAP_HSMMC_READ(host->base, IE);
>> +
>> +       if (enable) {
>> +               OMAP_HSMMC_WRITE(host->base, ISE, ise | CIRQ_ENABLE);
>> +               OMAP_HSMMC_WRITE(host->base, IE,  ie  | CIRQ_ENABLE);
>> +       } else {
>> +               OMAP_HSMMC_WRITE(host->base, ISE, ise & ~CIRQ_ENABLE);
>> +               OMAP_HSMMC_WRITE(host->base, IE,  ie  & ~CIRQ_ENABLE);
>> +       }
>> +
>> +}
>> +
>>  static const struct mmc_host_ops omap_hsmmc_ops = {
>>        .enable = omap_hsmmc_enable_fclk,
>>        .disable = omap_hsmmc_disable_fclk,
>> @@ -1519,7 +1557,7 @@ static const struct mmc_host_ops omap_hs
>>        .set_ios = omap_hsmmc_set_ios,
>>        .get_cd = omap_hsmmc_get_cd,
>>        .get_ro = omap_hsmmc_get_ro,
>> -       /* NYET -- enable_sdio_irq */
>> +       .enable_sdio_irq = omap_hsmmc_enable_sdio_irq,
>>  };
>>
>>  static const struct mmc_host_ops omap_hsmmc_ps_ops = {
>> @@ -1529,7 +1567,7 @@ static const struct mmc_host_ops omap_hs
>>        .set_ios = omap_hsmmc_set_ios,
>>        .get_cd = omap_hsmmc_get_cd,
>>        .get_ro = omap_hsmmc_get_ro,
>> -       /* NYET -- enable_sdio_irq */
>> +       .enable_sdio_irq = omap_hsmmc_enable_sdio_irq,
>>  };
>>
>>  #ifdef CONFIG_DEBUG_FS
>> @@ -1734,7 +1772,7 @@ static int __init omap_hsmmc_probe(struc
>>        mmc->max_seg_size = mmc->max_req_size;
>>
>>        mmc->caps |= MMC_CAP_MMC_HIGHSPEED | MMC_CAP_SD_HIGHSPEED |
>> -                    MMC_CAP_WAIT_WHILE_BUSY;
>> +                    MMC_CAP_WAIT_WHILE_BUSY | MMC_CAP_SDIO_IRQ;
>>
>>        if (mmc_slot(host).wires >= 8)
>>                mmc->caps |= MMC_CAP_8_BIT_DATA;
>>
>>
>