* [PATCH v2] mmc: mmci.c: Defer probe() in case of yet uninitialized GPIOs
@ 2012-06-16 16:49 ` Roland Stigge
0 siblings, 0 replies; 6+ messages in thread
From: Roland Stigge @ 2012-06-16 16:49 UTC (permalink / raw)
To: cjb, grant.likely, rob.herring, rmk+kernel, ulf.hansson,
linus.walleij, sebastian.rasmussen, linux-mmc, linux-kernel,
aletes.xgr, linux-arm-kernel
Cc: Roland Stigge
If the GPIOs used by the MMCI driver are not registered yet when the driver is
probe()d, they can't be used. This happens if the mmci driver is probed before
the respective GPIO controller (e.g. on the LPC32xx EA3250 board, the PCA9532
GPIO controller would be initialized via DT after mmci). Therefore, we defer
mmci in this case.
Signed-off-by: Roland Stigge <stigge@antcom.de>
---
drivers/mmc/host/mmci.c | 30 +++++++++++++++++++++++-------
1 file changed, 23 insertions(+), 7 deletions(-)
--- linux-2.6.orig/drivers/mmc/host/mmci.c
+++ linux-2.6/drivers/mmc/host/mmci.c
@@ -1215,13 +1215,21 @@ static void mmci_dt_populate_generic_pda
{
int bus_width = 0;
- pdata->gpio_wp = of_get_named_gpio(np, "wp-gpios", 0);
- if (!pdata->gpio_wp)
- pdata->gpio_wp = -1;
-
- pdata->gpio_cd = of_get_named_gpio(np, "cd-gpios", 0);
- if (!pdata->gpio_cd)
- pdata->gpio_cd = -1;
+ if (of_get_property(np, "wp-gpios", NULL)) {
+ pdata->gpio_wp = of_get_named_gpio(np, "wp-gpios", 0);
+ if (pdata->gpio_wp == -ENODEV)
+ pdata->gpio_wp = -EPROBE_DEFER;
+ } else {
+ pdata->gpio_wp = -ENODEV;
+ }
+
+ if (of_get_property(np, "cd-gpios", NULL)) {
+ pdata->gpio_cd = of_get_named_gpio(np, "cd-gpios", 0);
+ if (pdata->gpio_cd == -ENODEV)
+ pdata->gpio_cd = -EPROBE_DEFER;
+ } else {
+ pdata->gpio_cd = -ENODEV;
+ }
if (of_get_property(np, "cd-inverted", NULL))
pdata->cd_invert = true;
@@ -1424,6 +1432,10 @@ static int __devinit mmci_probe(struct a
writel(0, host->base + MMCIMASK1);
writel(0xfff, host->base + MMCICLEAR);
+ if (plat->gpio_cd == -EPROBE_DEFER) {
+ ret = -EPROBE_DEFER;
+ goto err_gpio_cd;
+ }
if (gpio_is_valid(plat->gpio_cd)) {
ret = gpio_request(plat->gpio_cd, DRIVER_NAME " (cd)");
if (ret == 0)
@@ -1447,6 +1459,10 @@ static int __devinit mmci_probe(struct a
if (ret >= 0)
host->gpio_cd_irq = gpio_to_irq(plat->gpio_cd);
}
+ if (plat->gpio_wp == -EPROBE_DEFER) {
+ ret = -EPROBE_DEFER;
+ goto err_gpio_wp;
+ }
if (gpio_is_valid(plat->gpio_wp)) {
ret = gpio_request(plat->gpio_wp, DRIVER_NAME " (wp)");
if (ret == 0)
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH v2] mmc: mmci.c: Defer probe() in case of yet uninitialized GPIOs
@ 2012-06-16 16:49 ` Roland Stigge
0 siblings, 0 replies; 6+ messages in thread
From: Roland Stigge @ 2012-06-16 16:49 UTC (permalink / raw)
To: linux-arm-kernel
If the GPIOs used by the MMCI driver are not registered yet when the driver is
probe()d, they can't be used. This happens if the mmci driver is probed before
the respective GPIO controller (e.g. on the LPC32xx EA3250 board, the PCA9532
GPIO controller would be initialized via DT after mmci). Therefore, we defer
mmci in this case.
Signed-off-by: Roland Stigge <stigge@antcom.de>
---
drivers/mmc/host/mmci.c | 30 +++++++++++++++++++++++-------
1 file changed, 23 insertions(+), 7 deletions(-)
--- linux-2.6.orig/drivers/mmc/host/mmci.c
+++ linux-2.6/drivers/mmc/host/mmci.c
@@ -1215,13 +1215,21 @@ static void mmci_dt_populate_generic_pda
{
int bus_width = 0;
- pdata->gpio_wp = of_get_named_gpio(np, "wp-gpios", 0);
- if (!pdata->gpio_wp)
- pdata->gpio_wp = -1;
-
- pdata->gpio_cd = of_get_named_gpio(np, "cd-gpios", 0);
- if (!pdata->gpio_cd)
- pdata->gpio_cd = -1;
+ if (of_get_property(np, "wp-gpios", NULL)) {
+ pdata->gpio_wp = of_get_named_gpio(np, "wp-gpios", 0);
+ if (pdata->gpio_wp == -ENODEV)
+ pdata->gpio_wp = -EPROBE_DEFER;
+ } else {
+ pdata->gpio_wp = -ENODEV;
+ }
+
+ if (of_get_property(np, "cd-gpios", NULL)) {
+ pdata->gpio_cd = of_get_named_gpio(np, "cd-gpios", 0);
+ if (pdata->gpio_cd == -ENODEV)
+ pdata->gpio_cd = -EPROBE_DEFER;
+ } else {
+ pdata->gpio_cd = -ENODEV;
+ }
if (of_get_property(np, "cd-inverted", NULL))
pdata->cd_invert = true;
@@ -1424,6 +1432,10 @@ static int __devinit mmci_probe(struct a
writel(0, host->base + MMCIMASK1);
writel(0xfff, host->base + MMCICLEAR);
+ if (plat->gpio_cd == -EPROBE_DEFER) {
+ ret = -EPROBE_DEFER;
+ goto err_gpio_cd;
+ }
if (gpio_is_valid(plat->gpio_cd)) {
ret = gpio_request(plat->gpio_cd, DRIVER_NAME " (cd)");
if (ret == 0)
@@ -1447,6 +1459,10 @@ static int __devinit mmci_probe(struct a
if (ret >= 0)
host->gpio_cd_irq = gpio_to_irq(plat->gpio_cd);
}
+ if (plat->gpio_wp == -EPROBE_DEFER) {
+ ret = -EPROBE_DEFER;
+ goto err_gpio_wp;
+ }
if (gpio_is_valid(plat->gpio_wp)) {
ret = gpio_request(plat->gpio_wp, DRIVER_NAME " (wp)");
if (ret == 0)
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v2] mmc: mmci.c: Defer probe() in case of yet uninitialized GPIOs
2012-06-16 16:49 ` Roland Stigge
@ 2012-06-16 17:23 ` Arnd Bergmann
-1 siblings, 0 replies; 6+ messages in thread
From: Arnd Bergmann @ 2012-06-16 17:23 UTC (permalink / raw)
To: linux-arm-kernel
Cc: Roland Stigge, cjb, grant.likely, rob.herring, rmk+kernel,
ulf.hansson, linus.walleij, sebastian.rasmussen, linux-mmc,
linux-kernel, aletes.xgr
On Saturday 16 June 2012, Roland Stigge wrote:
> + if (of_get_property(np, "wp-gpios", NULL)) {
> + pdata->gpio_wp = of_get_named_gpio(np, "wp-gpios", 0);
> + if (pdata->gpio_wp == -ENODEV)
> + pdata->gpio_wp = -EPROBE_DEFER;
> + } else {
> + pdata->gpio_wp = -ENODEV;
> + }
This is still very ugly and there is a certain danfer that we might
have to duplicate this across more drivers. Can't we make
of_get_named_gpio_flags return -EPROBE_DEFER in cases where we can't
find the GPIO number yet but still have a chance of returning it at
a later point?
Arnd
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH v2] mmc: mmci.c: Defer probe() in case of yet uninitialized GPIOs
@ 2012-06-16 17:23 ` Arnd Bergmann
0 siblings, 0 replies; 6+ messages in thread
From: Arnd Bergmann @ 2012-06-16 17:23 UTC (permalink / raw)
To: linux-arm-kernel
On Saturday 16 June 2012, Roland Stigge wrote:
> + if (of_get_property(np, "wp-gpios", NULL)) {
> + pdata->gpio_wp = of_get_named_gpio(np, "wp-gpios", 0);
> + if (pdata->gpio_wp == -ENODEV)
> + pdata->gpio_wp = -EPROBE_DEFER;
> + } else {
> + pdata->gpio_wp = -ENODEV;
> + }
This is still very ugly and there is a certain danfer that we might
have to duplicate this across more drivers. Can't we make
of_get_named_gpio_flags return -EPROBE_DEFER in cases where we can't
find the GPIO number yet but still have a chance of returning it at
a later point?
Arnd
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: [PATCH v2] mmc: mmci.c: Defer probe() in case of yet uninitialized GPIOs
2012-06-16 17:23 ` Arnd Bergmann
@ 2012-06-16 19:04 ` Roland Stigge
-1 siblings, 0 replies; 6+ messages in thread
From: Roland Stigge @ 2012-06-16 19:04 UTC (permalink / raw)
To: Arnd Bergmann
Cc: linux-arm-kernel, cjb, grant.likely, rob.herring, rmk+kernel,
ulf.hansson, linus.walleij, sebastian.rasmussen, linux-mmc,
linux-kernel, aletes.xgr
On 16/06/12 19:23, Arnd Bergmann wrote:
> On Saturday 16 June 2012, Roland Stigge wrote:
>> + if (of_get_property(np, "wp-gpios", NULL)) {
>> + pdata->gpio_wp = of_get_named_gpio(np, "wp-gpios", 0);
>> + if (pdata->gpio_wp == -ENODEV)
>> + pdata->gpio_wp = -EPROBE_DEFER;
>> + } else {
>> + pdata->gpio_wp = -ENODEV;
>> + }
>
> This is still very ugly and there is a certain danfer that we might
> have to duplicate this across more drivers. Can't we make
> of_get_named_gpio_flags return -EPROBE_DEFER in cases where we can't
> find the GPIO number yet but still have a chance of returning it at
> a later point?
OK, will post a new patch.
Roland
^ permalink raw reply [flat|nested] 6+ messages in thread* [PATCH v2] mmc: mmci.c: Defer probe() in case of yet uninitialized GPIOs
@ 2012-06-16 19:04 ` Roland Stigge
0 siblings, 0 replies; 6+ messages in thread
From: Roland Stigge @ 2012-06-16 19:04 UTC (permalink / raw)
To: linux-arm-kernel
On 16/06/12 19:23, Arnd Bergmann wrote:
> On Saturday 16 June 2012, Roland Stigge wrote:
>> + if (of_get_property(np, "wp-gpios", NULL)) {
>> + pdata->gpio_wp = of_get_named_gpio(np, "wp-gpios", 0);
>> + if (pdata->gpio_wp == -ENODEV)
>> + pdata->gpio_wp = -EPROBE_DEFER;
>> + } else {
>> + pdata->gpio_wp = -ENODEV;
>> + }
>
> This is still very ugly and there is a certain danfer that we might
> have to duplicate this across more drivers. Can't we make
> of_get_named_gpio_flags return -EPROBE_DEFER in cases where we can't
> find the GPIO number yet but still have a chance of returning it at
> a later point?
OK, will post a new patch.
Roland
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-06-16 19:04 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2012-06-16 16:49 [PATCH v2] mmc: mmci.c: Defer probe() in case of yet uninitialized GPIOs Roland Stigge
2012-06-16 16:49 ` Roland Stigge
2012-06-16 17:23 ` Arnd Bergmann
2012-06-16 17:23 ` Arnd Bergmann
2012-06-16 19:04 ` Roland Stigge
2012-06-16 19:04 ` Roland Stigge
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.