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.be...@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.be...@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;
