[PATCH v2 08/17] gpio: locomo: implement per-pin irq handling

Dmitry Eremin-Solenikov
2015-04-27T23:55:45Z

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(-)

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;
}

--
2.1.4