linux-toradex.git/include/linux/mmc/dw_mmc.h, branch v4.0.5

mmc: dw_mmc: Protect read-modify-write of INTMASK with a lock

2015-01-19T08:56:05+00:00

We're running into cases where our enabling of the SDIO interrupt in
dw_mmc doesn't actually take effect.  Specifically, adding patch like
this:

 +++ b/drivers/mmc/host/dw_mmc.c
 @@ -1076,6 +1076,9 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)

      mci_writel(host, INTMASK,
           (int_mask | SDMMC_INT_SDIO(slot->id)));
 +    int_mask = mci_readl(host, INTMASK);
 +    if (!(int_mask & SDMMC_INT_SDIO(slot->id)))
 +      dev_err(&mmc->class_dev, "failed to enable sdio irq\n");
    } else {

...actually triggers the error message.  That's because the
dw_mci_enable_sdio_irq() unsafely does a read-modify-write of the
INTMASK register.

We can't just use the standard host->lock since that lock is not irq
safe and mmc_signal_sdio_irq() (called from interrupt context) calls
dw_mci_enable_sdio_irq().  Add a new irq-safe lock to protect INTMASK.

An alternate solution to this is to punt mmc_signal_sdio_irq() to the
tasklet and then protect INTMASK modifications by the standard host
lock.  This seemed like a bit more of a high-latency change.

Reported-by: Bing Zhao 
Signed-off-by: Doug Anderson 
Reviewed-by: James Hogan 
Signed-off-by: Ulf Hansson

mmc: dw_mmc: add support for the other bit of sdio interrupt

2014-11-26T13:31:00+00:00

The bit of sdio interrupt is 16 in designware implementation,
but it is 24 on Rockchip SoCs.This patch add sdio_id0 for the
number of slot0 in the SDIO interrupt registers.

Signed-off-by: Addy Ke 
Reviewed-by: Doug Anderson 
Acked-by: Jaehoon Chung 
Signed-off-by: Ulf Hansson

mmc: dw_mmc: Add IDMAC 64-bit address mode support

2014-11-26T13:30:50+00:00

Synopsys DW_MMC IP core supports Internal DMA Controller with 64-bit address mode from IP version 2.70a onwards.
Updated the driver to support IDMAC 64-bit addressing mode.

Signed-off-by: Prabu Thangamuthu 
Reviewed-by: Alim Akhtar 
Acked-by: Jaehoon Chung 
Signed-off-by: Ulf Hansson

mmc: dw_mmc: Remove old card detect infrastructure

2014-11-10T11:40:39+00:00

The dw_mmc driver had a bunch of code that ran whenever a card was
ejected and inserted.  However, this code was old and crufty and
should be removed.  Some evidence that it's really not needed:

1. Is is supposed to be legal to use 'cd-gpio' on dw_mmc instead of
   using the built-in card detect mechanism.  The 'cd-gpio' code
   doesn't run any of the crufty old code but yet still works.

2. While looking at this, I realized that my old change (369ac86 mmc:
   dw_mmc: don't queue up a card detect at slot startup) actually
   castrated the old code a little bit already and nobody noticed.
   Specifically "last_detect_state" was left as 0 at bootup.  That
   means that on the first card removal none of the crufty code ran.

3. I can run "while true; do dd if=/dev/mmcblk1 of=/dev/null; done"
   while ejecting and inserting an SD Card and the world doesn't
   explode.

If some of the crufty old code is actually needed, we should justify
it and also put it in some place where it will be run even with
"cd-gpio".

Note that in my case I'm using the "cd-gpio" mechanism but for various
reasons the hardware triggers a dw_mmc "card detect" at bootup.  That
was actually causing a real bug.  The card detect workqueue was
running while the system was trying to enumerate the card.  The
"present != slot->last_detect_state" triggered and we were doing all
kinds of crazy stuff and messing up enumeration.  The new mechanism of
just asking the core to check the card is much safer and then the
bogus interrupt doesn't hurt.

Signed-off-by: Doug Anderson 
Tested-by: Jaehoon Chung 
Acked-by: Jaehoon Chung 
Tested-by: alim.akhtar 
Signed-off-by: Ulf Hansson

mmc: dw_mmc: Support voltage changes

2014-09-09T11:59:18+00:00

For UHS cards we need the ability to switch voltages from 3.3V to
1.8V.  Add support to the dw_mmc driver to handle this.  Note that
dw_mmc needs a little bit of extra code since the interface needs a
special bit programmed to the CMD register while CMD11 is progressing.
This means adding a few extra states to the state machine to track.

Signed-off-by: Doug Anderson 
Signed-off-by: Yuvaraj Kumar C D 
Signed-off-by: Ulf Hansson

mmc: dw_mmc: use mmc_regulator_get_supply to handle regulators

2014-09-09T11:59:18+00:00

This patch makes use of mmc_regulator_get_supply() to handle
the vmmc and vqmmc regulators.Also it moves the code handling
the these regulators to dw_mci_set_ios().It turned on the vmmc
and vqmmc during MMC_POWER_UP and MMC_POWER_ON,and turned off
during MMC_POWER_OFF.

Signed-off-by: Yuvaraj Kumar C D 
Signed-off-by: Ulf Hansson

mmc: dw_mmc: Slot quirk "disable-wp" is deprecated.

2014-08-11T09:42:39+00:00

Slot quirks "disable-wp" is deprecated.
Instead, use the host quirk "disable-wp".
(Because the slot-node is removed in dt-file.)

Signed-off-by: Jaehoon Chung 
Tested-by: Sachin Kamat 
Acked-by: Seungwon Jeon 
Reviewed-by: Doug Anderson 
Tested-by: Doug Anderson 
Signed-off-by: Ulf Hansson

mmc: dw_mmc: remove unused member variable.

2014-05-12T22:04:33+00:00

Since using the device-tree, didn't use the callback pointer.
So removed the unused callback pointer.
When the set_power callback is used, it should be added in future.

Signed-off-by: Jaehoon Chung 
Signed-off-by: Ulf Hansson 
Signed-off-by: Chris Ball

mmc: dw_mmc: guarantee stop-abort cmd in data errors

2013-09-26T01:35:40+00:00

In error cases, DTO interrupt may or may not be generated depending
on remained data. Stop/Abort command ensures DTO generation for that
situation. Currently if 'stop' field of data is empty, there is no
stop/abort command. So, it could hang waiting DTO. This change
reinforces these cases.

Signed-off-by: Seungwon Jeon 
Tested-by: Alim Akhtar 
Signed-off-by: Chris Ball

mmc: dw_mmc: control card read threshold

2013-09-26T01:34:39+00:00

Card Read Threshold should be ensured that the card clock does not stop
in the middle of a block of data being transferred from the card to the
Host. Specially, clock stop is allowed in fast transfer such as HS200
or SDR104 mode. And so, it should be enabled.

Signed-off-by: Seungwon Jeon 
Tested-by: Alim Akhtar 
Signed-off-by: Chris Ball