[v2,08/17] gpio: locomo: implement per-pin irq handling
diff mbox

Message ID 1430178954-11138-9-git-send-email-dbaryshkov@gmail.com
State New
Headers show

Commit Message

Dmitry Eremin-Solenikov April 27, 2015, 11:55 p.m. UTC
LoCoMo has a possibility to generate per-GPIO edge irqs. Support for
that was there in old locomo driver, got 'cleaned up' during old driver
IRQ cascading cleanup and is now reimplemented. It is expected that
SL-5500 (collie) will use locomo gpio irqs for mmc detection irq.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
---
 drivers/gpio/Kconfig       |   1 +
 drivers/gpio/gpio-locomo.c | 120 ++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 120 insertions(+), 1 deletion(-)

Comments

Linus Walleij May 6, 2015, 2:15 p.m. UTC | #1
On Tue, Apr 28, 2015 at 1:55 AM, Dmitry Eremin-Solenikov
<dbaryshkov@gmail.com> wrote:

> LoCoMo has a possibility to generate per-GPIO edge irqs. Support for
> that was there in old locomo driver, got 'cleaned up' during old driver
> IRQ cascading cleanup and is now reimplemented. It is expected that
> SL-5500 (collie) will use locomo gpio irqs for mmc detection irq.
>
> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>

Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Assume this will also go through MFD.

> +       irq_set_chained_handler(lg->irq, NULL);
> +       irq_set_handler_data(lg->irq, NULL);

Why is this needed? If the GPIOLIB_IRQCHIP code in
gpiolib.c is not doing this then maybe it's the core code that
needs fixing rather than having this in the driver.

Yours,
Linus Walleij
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Dmitry Eremin-Solenikov May 6, 2015, 4:42 p.m. UTC | #2
2015-05-06 17:15 GMT+03:00 Linus Walleij <linus.walleij@linaro.org>:
> On Tue, Apr 28, 2015 at 1:55 AM, Dmitry Eremin-Solenikov
> <dbaryshkov@gmail.com> wrote:
>
>> LoCoMo has a possibility to generate per-GPIO edge irqs. Support for
>> that was there in old locomo driver, got 'cleaned up' during old driver
>> IRQ cascading cleanup and is now reimplemented. It is expected that
>> SL-5500 (collie) will use locomo gpio irqs for mmc detection irq.
>>
>> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
>
> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>

Thanks for review of the patches.

> Assume this will also go through MFD.
>
>> +       irq_set_chained_handler(lg->irq, NULL);
>> +       irq_set_handler_data(lg->irq, NULL);
>
> Why is this needed? If the GPIOLIB_IRQCHIP code in
> gpiolib.c is not doing this then maybe it's the core code that
> needs fixing rather than having this in the driver.

I have skimmed through the rest of drivers using
gpiochip_set_chained_irqchip(). Indeed none of the drivers NULL
the chained handled and handler data. However I couldn't locate
the code where they would be cleared.

Should I still send the patch fixing the GPIOLIB_IRQCHIP?

>
> Yours,
> Linus Walleij
Linus Walleij May 12, 2015, 11:15 a.m. UTC | #3
On Wed, May 6, 2015 at 6:42 PM, Dmitry Eremin-Solenikov
<dbaryshkov@gmail.com> wrote:
> 2015-05-06 17:15 GMT+03:00 Linus Walleij <linus.walleij@linaro.org>:
>> On Tue, Apr 28, 2015 at 1:55 AM, Dmitry Eremin-Solenikov
>> <dbaryshkov@gmail.com> wrote:
>>
>>> LoCoMo has a possibility to generate per-GPIO edge irqs. Support for
>>> that was there in old locomo driver, got 'cleaned up' during old driver
>>> IRQ cascading cleanup and is now reimplemented. It is expected that
>>> SL-5500 (collie) will use locomo gpio irqs for mmc detection irq.
>>>
>>> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
>>
>> Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
>
> Thanks for review of the patches.
>
>> Assume this will also go through MFD.
>>
>>> +       irq_set_chained_handler(lg->irq, NULL);
>>> +       irq_set_handler_data(lg->irq, NULL);
>>
>> Why is this needed? If the GPIOLIB_IRQCHIP code in
>> gpiolib.c is not doing this then maybe it's the core code that
>> needs fixing rather than having this in the driver.
>
> I have skimmed through the rest of drivers using
> gpiochip_set_chained_irqchip(). Indeed none of the drivers NULL
> the chained handled and handler data. However I couldn't locate
> the code where they would be cleared.
>
> Should I still send the patch fixing the GPIOLIB_IRQCHIP?

Yes I guess you need to save parent_irq in struct gpio_chip and
remove it in gpiochip_irqchip_remove() if it's != 0.

Yours,
Linus Walleij
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Patch
diff mbox

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 4542684..6b77614 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -737,6 +737,7 @@  config GPIO_KEMPLD
 config GPIO_LOCOMO
 	bool "Sharp LoCoMo GPIO support"
 	depends on MFD_LOCOMO
+	select GPIOLIB_IRQCHIP
 	help
 	  Select this to support GPIO pins on Sharp LoCoMo Grid Array found
 	  in Sharp Zaurus collie and poodle models.
diff --git a/drivers/gpio/gpio-locomo.c b/drivers/gpio/gpio-locomo.c
index dd9a1ca..d8e5880 100644
--- a/drivers/gpio/gpio-locomo.c
+++ b/drivers/gpio/gpio-locomo.c
@@ -16,13 +16,15 @@ 
 #include <linux/slab.h>
 #include <linux/bitops.h>
 #include <linux/err.h>
-#include <linux/gpio.h>
+#include <linux/gpio/driver.h>
 #include <linux/io.h>
+#include <linux/irq.h>
 #include <linux/regmap.h>
 #include <linux/mfd/locomo.h>
 
 struct locomo_gpio {
 	struct regmap *regmap;
+	int irq;
 
 	struct gpio_chip gpio;
 
@@ -79,6 +81,99 @@  static int locomo_gpio_direction_output(struct gpio_chip *chip,
 	return 0;
 }
 
+static void
+locomo_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
+{
+	struct gpio_chip *chip = irq_get_handler_data(irq);
+	struct locomo_gpio *lg = container_of(chip, struct locomo_gpio, gpio);
+	struct irq_chip *irqchip = irq_desc_get_chip(desc);
+	unsigned int gir;
+	unsigned int gpd;
+	unsigned int req;
+
+	chained_irq_enter(irqchip, desc);
+
+	while (1) {
+		regmap_read(lg->regmap, LOCOMO_GIR, &gir);
+		regmap_read(lg->regmap, LOCOMO_GPD, &gpd);
+		req = gir & gpd;
+
+		if (!req)
+			break;
+
+		generic_handle_irq(irq_find_mapping(lg->gpio.irqdomain,
+					ffs(req) - 1));
+	}
+
+	chained_irq_exit(irqchip, desc);
+}
+
+static void locomo_gpio_ack_irq(struct irq_data *d)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
+	struct locomo_gpio *lg = container_of(chip, struct locomo_gpio, gpio);
+	unsigned int mask = BIT(d->hwirq);
+
+	regmap_update_bits(lg->regmap, LOCOMO_GWE, mask, mask);
+	regmap_update_bits(lg->regmap, LOCOMO_GIS, mask, 0);
+	regmap_update_bits(lg->regmap, LOCOMO_GWE, mask, 0);
+}
+
+static void locomo_gpio_mask_irq(struct irq_data *d)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
+	struct locomo_gpio *lg = container_of(chip, struct locomo_gpio, gpio);
+	unsigned int mask = BIT(d->hwirq);
+
+	regmap_update_bits(lg->regmap, LOCOMO_GIE, mask, 0);
+}
+
+static void locomo_gpio_unmask_irq(struct irq_data *d)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
+	struct locomo_gpio *lg = container_of(chip, struct locomo_gpio, gpio);
+	unsigned int mask = BIT(d->hwirq);
+
+	regmap_update_bits(lg->regmap, LOCOMO_GIE, mask, mask);
+}
+
+static int locomo_gpio_type_irq(struct irq_data *d, unsigned int type)
+{
+	struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
+	struct locomo_gpio *lg = container_of(chip, struct locomo_gpio, gpio);
+	unsigned int mask;
+
+	mask = BIT(d->hwirq);
+
+	if (type == IRQ_TYPE_PROBE) {
+		if ((lg->rising_edge | lg->falling_edge) & mask)
+			return 0;
+		type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
+	}
+
+	if (type & IRQ_TYPE_EDGE_RISING)
+		lg->rising_edge |= mask;
+	else
+		lg->rising_edge &= ~mask;
+	if (type & IRQ_TYPE_EDGE_FALLING)
+		lg->falling_edge |= mask;
+	else
+		lg->falling_edge &= ~mask;
+
+	regmap_write(lg->regmap, LOCOMO_GRIE, lg->rising_edge);
+	regmap_write(lg->regmap, LOCOMO_GFIE, lg->falling_edge);
+
+	return 0;
+}
+
+static struct irq_chip locomo_gpio_irq_chip = {
+	.name		= "LOCOMO-g",
+	.irq_ack	= locomo_gpio_ack_irq,
+	.irq_mask	= locomo_gpio_mask_irq,
+	.irq_unmask	= locomo_gpio_unmask_irq,
+	.irq_set_type	= locomo_gpio_type_irq,
+};
+
 #ifdef CONFIG_PM_SLEEP
 static int locomo_gpio_suspend(struct device *dev)
 {
@@ -119,6 +214,10 @@  static int locomo_gpio_probe(struct platform_device *pdev)
 	if (!lg)
 		return -ENOMEM;
 
+	lg->irq = platform_get_irq(pdev, 0);
+	if (lg->irq < 0)
+		return -ENXIO;
+
 	lg->regmap = dev_get_regmap(pdev->dev.parent, NULL);
 	if (!lg->regmap)
 		return -EINVAL;
@@ -130,6 +229,7 @@  static int locomo_gpio_probe(struct platform_device *pdev)
 	regmap_write(lg->regmap, LOCOMO_GPD, 0x00);
 	regmap_write(lg->regmap, LOCOMO_GIE, 0x00);
 
+	lg->gpio.dev = &pdev->dev;
 	lg->gpio.base = pdata ? pdata->gpio_base : -1;
 	lg->gpio.label = "locomo-gpio";
 	lg->gpio.ngpio = 16;
@@ -142,7 +242,22 @@  static int locomo_gpio_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
+	ret = gpiochip_irqchip_add(&lg->gpio, &locomo_gpio_irq_chip, 0,
+				   handle_level_irq, IRQ_TYPE_NONE);
+	if (ret) {
+		dev_err(&pdev->dev, "Failed to add irq chip\n");
+		goto err_rm_gpiochip;
+	}
+
+	gpiochip_set_chained_irqchip(&lg->gpio, &locomo_gpio_irq_chip, lg->irq,
+				     locomo_gpio_irq_handler);
+
 	return 0;
+
+err_rm_gpiochip:
+	gpiochip_remove(&lg->gpio);
+
+	return ret;
 }
 
 static int locomo_gpio_remove(struct platform_device *pdev)
@@ -151,6 +266,9 @@  static int locomo_gpio_remove(struct platform_device *pdev)
 
 	gpiochip_remove(&lg->gpio);
 
+	irq_set_chained_handler(lg->irq, NULL);
+	irq_set_handler_data(lg->irq, NULL);
+
 	return 0;
 }