LinuxLists.cc - [PATCH 1/2] gpio/omap: maintain GPIO and IRQ usage separately

2013-09-25 00:37:54

Subject: [PATCH 1/2] gpio/omap: maintain GPIO and IRQ usage separately

The GPIO OMAP controller pins can be used as IRQ and GPIO
independently so is necessary to keep track GPIO pins and
IRQ lines usage separately to make sure that the bank will
always be enabled while being used.

Also move gpio_is_input() definition in preparation for the
next patch that setups the controller's irq_chip driver when
a caller requests an interrupt line.

Signed-off-by: Javier Martinez Canillas <[email protected]>
---
drivers/gpio/gpio-omap.c | 35 +++++++++++++++++++++--------------
1 file changed, 21 insertions(+), 14 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index 0ff4355..a4fe038 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -63,6 +63,7 @@ struct gpio_bank {
struct gpio_chip chip;
struct clk *dbck;
u32 mod_usage;
+ u32 irq_usage;
u32 dbck_enable_mask;
bool dbck_enabled;
struct device *dev;
@@ -86,6 +87,9 @@ struct gpio_bank {
#define GPIO_BIT(bank, gpio) (1 << GPIO_INDEX(bank, gpio))
#define GPIO_MOD_CTRL_BIT BIT(0)

+#define BANK_USED(bank) (bank->mod_usage || bank->irq_usage)
+#define LINE_USED(line, offset) (line & (1 << offset))
+
static int irq_to_gpio(struct gpio_bank *bank, unsigned int gpio_irq)
{
return bank->chip.base + gpio_irq;
@@ -420,6 +424,13 @@ static int _set_gpio_triggering(struct gpio_bank *bank, int gpio,
return 0;
}

+static int gpio_is_input(struct gpio_bank *bank, int mask)
+{
+ void __iomem *reg = bank->base + bank->regs->direction;
+
+ return __raw_readl(reg) & mask;
+}
+
static int gpio_irq_type(struct irq_data *d, unsigned type)
{
struct gpio_bank *bank = irq_data_get_irq_chip_data(d);
@@ -427,7 +438,7 @@ static int gpio_irq_type(struct irq_data *d, unsigned type)
int retval;
unsigned long flags;

- if (WARN_ON(!bank->mod_usage))
+ if (WARN_ON(!BANK_USED(bank)))
return -EINVAL;

#ifdef CONFIG_ARCH_OMAP1
@@ -447,6 +458,7 @@ static int gpio_irq_type(struct irq_data *d, unsigned type)

spin_lock_irqsave(&bank->lock, flags);
retval = _set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), type);
+ bank->irq_usage |= 1 << GPIO_INDEX(bank, gpio);
spin_unlock_irqrestore(&bank->lock, flags);

if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
@@ -603,7 +615,7 @@ static int omap_gpio_request(struct gpio_chip *chip, unsigned offset)
* If this is the first gpio_request for the bank,
* enable the bank module.
*/
- if (!bank->mod_usage)
+ if (!BANK_USED(bank))
pm_runtime_get_sync(bank->dev);

spin_lock_irqsave(&bank->lock, flags);
@@ -619,7 +631,7 @@ static int omap_gpio_request(struct gpio_chip *chip, unsigned offset)
__raw_writel(__raw_readl(reg) | (1 << offset), reg);
}

- if (bank->regs->ctrl && !bank->mod_usage) {
+ if (bank->regs->ctrl && !BANK_USED(bank)) {
void __iomem *reg = bank->base + bank->regs->ctrl;
u32 ctrl;

@@ -654,7 +666,7 @@ static void omap_gpio_free(struct gpio_chip *chip, unsigned offset)

bank->mod_usage &= ~(1 << offset);

- if (bank->regs->ctrl && !bank->mod_usage) {
+ if (bank->regs->ctrl && !BANK_USED(bank)) {
void __iomem *reg = bank->base + bank->regs->ctrl;
u32 ctrl;

@@ -672,7 +684,7 @@ static void omap_gpio_free(struct gpio_chip *chip, unsigned offset)
* If this is the last gpio to be freed in the bank,
* disable the bank module.
*/
- if (!bank->mod_usage)
+ if (!BANK_USED(bank))
pm_runtime_put(bank->dev);
}

@@ -762,8 +774,10 @@ static void gpio_irq_shutdown(struct irq_data *d)
struct gpio_bank *bank = irq_data_get_irq_chip_data(d);
unsigned int gpio = irq_to_gpio(bank, d->hwirq);
unsigned long flags;
+ unsigned offset = GPIO_INDEX(bank, gpio);

spin_lock_irqsave(&bank->lock, flags);
+ bank->irq_usage &= ~(1 << offset);
_reset_gpio(bank, gpio);
spin_unlock_irqrestore(&bank->lock, flags);
}
@@ -897,13 +911,6 @@ static int gpio_input(struct gpio_chip *chip, unsigned offset)
return 0;
}

-static int gpio_is_input(struct gpio_bank *bank, int mask)
-{
- void __iomem *reg = bank->base + bank->regs->direction;
-
- return __raw_readl(reg) & mask;
-}
-
static int gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct gpio_bank *bank;
@@ -1400,7 +1407,7 @@ void omap2_gpio_prepare_for_idle(int pwr_mode)
struct gpio_bank *bank;

list_for_each_entry(bank, &omap_gpio_list, node) {
- if (!bank->mod_usage || !bank->loses_context)
+ if (!BANK_USED(bank) || !bank->loses_context)
continue;

bank->power_mode = pwr_mode;
@@ -1414,7 +1421,7 @@ void omap2_gpio_resume_after_idle(void)
struct gpio_bank *bank;

list_for_each_entry(bank, &omap_gpio_list, node) {
- if (!bank->mod_usage || !bank->loses_context)
+ if (!BANK_USED(bank) || !bank->loses_context)
continue;

pm_runtime_get_sync(bank->dev);
--
1.8.4.rc3

2013-09-25 00:38:00

by Javier Martinez Canillas

[permalink] [raw]

Subject: [PATCH 2/2] gpio/omap: auto-setup a GPIO when used as an IRQ

The OMAP GPIO controller HW requires a pin to be configured in GPIO
input mode in order to operate as an interrupt input. Since drivers
should not be aware of whether an interrupt pin is also a GPIO or not,
the HW should be fully configured/enabled as an IRQ if a driver solely
uses IRQ APIs such as request_irq(), and never calls any GPIO-related
APIs. As such, add the missing HW setup to the OMAP GPIO controller's
irq_chip driver.

Since this bypasses the GPIO subsystem we have to ensure that another
driver won't be able to request the same GPIO pin that is used as an
IRQ and set its direction as output. Requesting the GPIO and setting
its direction as input is allowed though.

This fixes smsc911x ethernet support for tobi and igep OMAP3 boards
and OMAP4 SDP SPI based ethernet that use a GPIO as an interrupt line.

Signed-off-by: Javier Martinez Canillas <[email protected]>
---
drivers/gpio/gpio-omap.c | 129 ++++++++++++++++++++++++++++++-----------------
1 file changed, 83 insertions(+), 46 deletions(-)

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index a4fe038..89675f8 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -424,6 +424,52 @@ static int _set_gpio_triggering(struct gpio_bank *bank, int gpio,
return 0;
}

+static void _enable_gpio_module(struct gpio_bank *bank, unsigned offset)
+{
+ if (bank->regs->pinctrl) {
+ void __iomem *reg = bank->base + bank->regs->pinctrl;
+
+ /* Claim the pin for MPU */
+ __raw_writel(__raw_readl(reg) | (1 << offset), reg);
+ }
+
+ if (bank->regs->ctrl && !BANK_USED(bank)) {
+ void __iomem *reg = bank->base + bank->regs->ctrl;
+ u32 ctrl;
+
+ ctrl = __raw_readl(reg);
+ /* Module is enabled, clocks are not gated */
+ ctrl &= ~GPIO_MOD_CTRL_BIT;
+ __raw_writel(ctrl, reg);
+ bank->context.ctrl = ctrl;
+ }
+}
+
+static void _disable_gpio_module(struct gpio_bank *bank, unsigned offset)
+{
+ void __iomem *base = bank->base;
+
+ if (bank->regs->wkup_en &&
+ !LINE_USED(bank->mod_usage, offset) &&
+ !LINE_USED(bank->irq_usage, offset)) {
+ /* Disable wake-up during idle for dynamic tick */
+ _gpio_rmw(base, bank->regs->wkup_en, 1 << offset, 0);
+ bank->context.wake_en =
+ __raw_readl(bank->base + bank->regs->wkup_en);
+ }
+
+ if (bank->regs->ctrl && !BANK_USED(bank)) {
+ void __iomem *reg = bank->base + bank->regs->ctrl;
+ u32 ctrl;
+
+ ctrl = __raw_readl(reg);
+ /* Module is disabled, clocks are gated */
+ ctrl |= GPIO_MOD_CTRL_BIT;
+ __raw_writel(ctrl, reg);
+ bank->context.ctrl = ctrl;
+ }
+}
+
static int gpio_is_input(struct gpio_bank *bank, int mask)
{
void __iomem *reg = bank->base + bank->regs->direction;
@@ -437,9 +483,10 @@ static int gpio_irq_type(struct irq_data *d, unsigned type)
unsigned gpio = 0;
int retval;
unsigned long flags;
+ unsigned offset;

- if (WARN_ON(!BANK_USED(bank)))
- return -EINVAL;
+ if (!BANK_USED(bank))
+ pm_runtime_get_sync(bank->dev);

#ifdef CONFIG_ARCH_OMAP1
if (d->irq > IH_MPUIO_BASE)
@@ -457,7 +504,16 @@ static int gpio_irq_type(struct irq_data *d, unsigned type)
return -EINVAL;

spin_lock_irqsave(&bank->lock, flags);
- retval = _set_gpio_triggering(bank, GPIO_INDEX(bank, gpio), type);
+ offset = GPIO_INDEX(bank, gpio);
+ retval = _set_gpio_triggering(bank, offset, type);
+ if (!LINE_USED(bank->mod_usage, offset)) {
+ _enable_gpio_module(bank, offset);
+ _set_gpio_direction(bank, offset, 1);
+ } else if (!gpio_is_input(bank, 1 << offset)) {
+ spin_unlock_irqrestore(&bank->lock, flags);
+ return -EINVAL;
+ }
+
bank->irq_usage |= 1 << GPIO_INDEX(bank, gpio);
spin_unlock_irqrestore(&bank->lock, flags);

@@ -620,30 +676,14 @@ static int omap_gpio_request(struct gpio_chip *chip, unsigned offset)

spin_lock_irqsave(&bank->lock, flags);
/* Set trigger to none. You need to enable the desired trigger with
- * request_irq() or set_irq_type().
+ * request_irq() or set_irq_type(). Only do this if the IRQ line has
+ * not already been requested.
*/
- _set_gpio_triggering(bank, offset, IRQ_TYPE_NONE);
-
- if (bank->regs->pinctrl) {
- void __iomem *reg = bank->base + bank->regs->pinctrl;
-
- /* Claim the pin for MPU */
- __raw_writel(__raw_readl(reg) | (1 << offset), reg);
+ if (!LINE_USED(bank->irq_usage, offset)) {
+ _set_gpio_triggering(bank, offset, IRQ_TYPE_NONE);
+ _enable_gpio_module(bank, offset);
}
-
- if (bank->regs->ctrl && !BANK_USED(bank)) {
- void __iomem *reg = bank->base + bank->regs->ctrl;
- u32 ctrl;
-
- ctrl = __raw_readl(reg);
- /* Module is enabled, clocks are not gated */
- ctrl &= ~GPIO_MOD_CTRL_BIT;
- __raw_writel(ctrl, reg);
- bank->context.ctrl = ctrl;
- }
-
bank->mod_usage |= 1 << offset;
-
spin_unlock_irqrestore(&bank->lock, flags);

return 0;
@@ -652,31 +692,11 @@ static int omap_gpio_request(struct gpio_chip *chip, unsigned offset)
static void omap_gpio_free(struct gpio_chip *chip, unsigned offset)
{
struct gpio_bank *bank = container_of(chip, struct gpio_bank, chip);
- void __iomem *base = bank->base;
unsigned long flags;

spin_lock_irqsave(&bank->lock, flags);
-
- if (bank->regs->wkup_en) {
- /* Disable wake-up during idle for dynamic tick */
- _gpio_rmw(base, bank->regs->wkup_en, 1 << offset, 0);
- bank->context.wake_en =
- __raw_readl(bank->base + bank->regs->wkup_en);
- }
-
bank->mod_usage &= ~(1 << offset);
-
- if (bank->regs->ctrl && !BANK_USED(bank)) {
- void __iomem *reg = bank->base + bank->regs->ctrl;
- u32 ctrl;
-
- ctrl = __raw_readl(reg);
- /* Module is disabled, clocks are gated */
- ctrl |= GPIO_MOD_CTRL_BIT;
- __raw_writel(ctrl, reg);
- bank->context.ctrl = ctrl;
- }
-
+ _disable_gpio_module(bank, offset);
_reset_gpio(bank, bank->chip.base + offset);
spin_unlock_irqrestore(&bank->lock, flags);

@@ -778,8 +798,16 @@ static void gpio_irq_shutdown(struct irq_data *d)

spin_lock_irqsave(&bank->lock, flags);
bank->irq_usage &= ~(1 << offset);
+ _disable_gpio_module(bank, offset);
_reset_gpio(bank, gpio);
spin_unlock_irqrestore(&bank->lock, flags);
+
+ /*
+ * If this is the last IRQ to be freed in the bank,
+ * disable the bank module.
+ */
+ if (!BANK_USED(bank))
+ pm_runtime_put(bank->dev);
}

static void gpio_ack_irq(struct irq_data *d)
@@ -929,13 +957,22 @@ static int gpio_output(struct gpio_chip *chip, unsigned offset, int value)
{
struct gpio_bank *bank;
unsigned long flags;
+ int retval = 0;

bank = container_of(chip, struct gpio_bank, chip);
spin_lock_irqsave(&bank->lock, flags);
+
+ if (LINE_USED(bank->irq_usage, offset)) {
+ retval = -EINVAL;
+ goto exit;
+ }
+
bank->set_dataout(bank, offset, value);
_set_gpio_direction(bank, offset, 0);
+
+exit:
spin_unlock_irqrestore(&bank->lock, flags);
- return 0;
+ return retval;
}

static int gpio_debounce(struct gpio_chip *chip, unsigned offset,
--
1.8.4.rc3

2013-09-25 00:38:31

by Javier Martinez Canillas

[permalink] [raw]

Subject: [PATCH 2/2] gpio/omap: auto-setup a GPIO when used as an IRQ

2013-09-27 14:31:08

by Lars Poeschel

[permalink] [raw]

Subject: Re: [PATCH 1/2] gpio/omap: maintain GPIO and IRQ usage separately

On Friday 27 September 2013 02:36:52, Javier Martinez Canillas wrote:
> The GPIO OMAP controller pins can be used as IRQ and GPIO
> independently so is necessary to keep track GPIO pins and
> IRQ lines usage separately to make sure that the bank will
> always be enabled while being used.
>
> Also move gpio_is_input() definition in preparation for the
> next patch that setups the controller's irq_chip driver when
> a caller requests an interrupt line.
>
> Signed-off-by: Javier Martinez Canillas <[email protected]>

For both patches:

Tested-by: Lars Poeschel <[email protected]>

on an am3359 (which is DT booting).

2013-09-27 18:08:51

by Kevin Hilman

[permalink] [raw]

Subject: Re: [PATCH 1/2] gpio/omap: maintain GPIO and IRQ usage separately

Javier Martinez Canillas <[email protected]> writes:

> The GPIO OMAP controller pins can be used as IRQ and GPIO
> independently so is necessary to keep track GPIO pins and
> IRQ lines usage separately to make sure that the bank will
> always be enabled while being used.
>
> Also move gpio_is_input() definition in preparation for the
> next patch that setups the controller's irq_chip driver when
> a caller requests an interrupt line.
>
> Signed-off-by: Javier Martinez Canillas <[email protected]>

I'm fine with this appproach. For both patches:

Reviewed-by: Kevin Hilman <[email protected]>

Also, I gave it a spin across a handful of OMAP boards using v3.12-rc2 +
these 2 patches.

Boot tested successfully with DT boot:

omap3530/beagle
omap3730/beagle-xm
omap3530/overo (Tobi w/GPIO IRQ networking)
omap3730/overo STORM (w/GPIO IRQ for networking)
am335x/beaglebone
am335x/beaglebone black
omap4430/panda
omap4460/panda-es
omap5912/OSK (omap1)

I also verified non-DT boot on the OMAP3 platforms that still support
legacy boot.

So feel free to also add

Tested-by: Kevin Hilman <[email protected]>

Thanks for your persistence in getting a fix for this upstream.

Kevin

2013-09-27 19:32:16

by Santosh Shilimkar

[permalink] [raw]

Subject: Re: [PATCH 1/2] gpio/omap: maintain GPIO and IRQ usage separately

On Tuesday 24 September 2013 08:36 PM, Javier Martinez Canillas wrote:
> The GPIO OMAP controller pins can be used as IRQ and GPIO
> independently so is necessary to keep track GPIO pins and
> IRQ lines usage separately to make sure that the bank will
> always be enabled while being used.
>
> Also move gpio_is_input() definition in preparation for the
> next patch that setups the controller's irq_chip driver when
> a caller requests an interrupt line.
>
> Signed-off-by: Javier Martinez Canillas <[email protected]>
> ---
Considering GPIO core maintainer is fine with this approach,
am fine with both of your patches. Again thanks a lot for
fixing the long nagging issue.

FWIW,
Acked-by: Santosh Shilimkar <[email protected]>

2013-09-27 21:02:07

by Tony Lindgren

[permalink] [raw]

Subject: Re: [PATCH 1/2] gpio/omap: maintain GPIO and IRQ usage separately

* Javier Martinez Canillas <[email protected]> [130924 17:45]:
> The GPIO OMAP controller pins can be used as IRQ and GPIO
> independently so is necessary to keep track GPIO pins and
> IRQ lines usage separately to make sure that the bank will
> always be enabled while being used.
>
> Also move gpio_is_input() definition in preparation for the
> next patch that setups the controller's irq_chip driver when
> a caller requests an interrupt line.
>
> Signed-off-by: Javier Martinez Canillas <[email protected]>

Thanks both of these look good to me for fixing
the regression:

Acked-by: Tony Lindgren <[email protected]>

2013-10-01 07:35:03

by Javier Martinez Canillas

[permalink] [raw]

Subject: Re: [PATCH 1/2] gpio/omap: maintain GPIO and IRQ usage separately

On 09/27/2013 08:08 PM, Kevin Hilman wrote:
> Javier Martinez Canillas <[email protected]> writes:
>
>> The GPIO OMAP controller pins can be used as IRQ and GPIO
>> independently so is necessary to keep track GPIO pins and
>> IRQ lines usage separately to make sure that the bank will
>> always be enabled while being used.
>>
>> Also move gpio_is_input() definition in preparation for the
>> next patch that setups the controller's irq_chip driver when
>> a caller requests an interrupt line.
>>
>> Signed-off-by: Javier Martinez Canillas <[email protected]>
>
> I'm fine with this appproach. For both patches:
>
> Reviewed-by: Kevin Hilman <[email protected]>
>
> Also, I gave it a spin across a handful of OMAP boards using v3.12-rc2 +
> these 2 patches.
>
> Boot tested successfully with DT boot:
>
> omap3530/beagle
> omap3730/beagle-xm
> omap3530/overo (Tobi w/GPIO IRQ networking)
> omap3730/overo STORM (w/GPIO IRQ for networking)
> am335x/beaglebone
> am335x/beaglebone black
> omap4430/panda
> omap4460/panda-es
> omap5912/OSK (omap1)
>
> I also verified non-DT boot on the OMAP3 platforms that still support
> legacy boot.
>
> So feel free to also add
>
> Tested-by: Kevin Hilman <[email protected]>
>
> Thanks for your persistence in getting a fix for this upstream.
>
> Kevin
>

Thanks a lot Kevin for testing on so many boards.

Linus,

Since this patch-set doesn't cause any regression and fix a long standing issue
on OMAP, do you think that it would be possible to include on the -rc series as
a bugfix or do you prefer to wait until 3.13?

Thanks a lot and best regards,
Javier

2013-10-01 11:14:44

by Linus Walleij

[permalink] [raw]

Subject: Re: [PATCH 1/2] gpio/omap: maintain GPIO and IRQ usage separately

On Tue, Oct 1, 2013 at 9:34 AM, Javier Martinez Canillas
<[email protected]> wrote:

> Linus,
>
> Since this patch-set doesn't cause any regression and fix a long standing issue
> on OMAP, do you think that it would be possible to include on the -rc series as
> a bugfix or do you prefer to wait until 3.13?

I've added it to my fixes branch for v3.12. Since linux-next is not available we
need some extensive build testing first to make sure that if something explodes
it explodes on OMAP only.

So will let this boil a few days and then send a pull request.

Yours,
Linus Walleij