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Subject[PATCH 5.4 036/109] gpio: pca953x: Override IRQ for one of the expanders on Galileo Gen 2
Date
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

[ Upstream commit ba8c90c6184784b397807b72403656085ac2f8c1 ]

ACPI table on Intel Galileo Gen 2 has wrong pin number for IRQ resource
of one of the I²C GPIO expanders. Since we know what that number is and
luckily have GPIO bases fixed for SoC's controllers, we may use a simple
DMI quirk to match the platform and retrieve GpioInt() pin on it for
the expander in question.

Mika suggested the way to avoid a quirk in the GPIO ACPI library and
here is the second, almost rewritten version of it.

Fixes: f32517bf1ae0 ("gpio: pca953x: support ACPI devices found on Galileo Gen2")
Depends-on: 25e3ef894eef ("gpio: acpi: Split out acpi_gpio_get_irq_resource() helper")
Suggested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpio/gpio-pca953x.c | 79 +++++++++++++++++++++++++++++++++++++
1 file changed, 79 insertions(+)

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index 29ba26742c8f5..c935019c0257c 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -107,6 +107,79 @@ static const struct i2c_device_id pca953x_id[] = {
};
MODULE_DEVICE_TABLE(i2c, pca953x_id);

+#ifdef CONFIG_GPIO_PCA953X_IRQ
+
+#include <linux/dmi.h>
+#include <linux/gpio.h>
+#include <linux/list.h>
+
+static const struct dmi_system_id pca953x_dmi_acpi_irq_info[] = {
+ {
+ /*
+ * On Intel Galileo Gen 2 board the IRQ pin of one of
+ * the I²C GPIO expanders, which has GpioInt() resource,
+ * is provided as an absolute number instead of being
+ * relative. Since first controller (gpio-sch.c) and
+ * second (gpio-dwapb.c) are at the fixed bases, we may
+ * safely refer to the number in the global space to get
+ * an IRQ out of it.
+ */
+ .matches = {
+ DMI_EXACT_MATCH(DMI_BOARD_NAME, "GalileoGen2"),
+ },
+ },
+ {}
+};
+
+#ifdef CONFIG_ACPI
+static int pca953x_acpi_get_pin(struct acpi_resource *ares, void *data)
+{
+ struct acpi_resource_gpio *agpio;
+ int *pin = data;
+
+ if (acpi_gpio_get_irq_resource(ares, &agpio))
+ *pin = agpio->pin_table[0];
+ return 1;
+}
+
+static int pca953x_acpi_find_pin(struct device *dev)
+{
+ struct acpi_device *adev = ACPI_COMPANION(dev);
+ int pin = -ENOENT, ret;
+ LIST_HEAD(r);
+
+ ret = acpi_dev_get_resources(adev, &r, pca953x_acpi_get_pin, &pin);
+ acpi_dev_free_resource_list(&r);
+ if (ret < 0)
+ return ret;
+
+ return pin;
+}
+#else
+static inline int pca953x_acpi_find_pin(struct device *dev) { return -ENXIO; }
+#endif
+
+static int pca953x_acpi_get_irq(struct device *dev)
+{
+ int pin, ret;
+
+ pin = pca953x_acpi_find_pin(dev);
+ if (pin < 0)
+ return pin;
+
+ dev_info(dev, "Applying ACPI interrupt quirk (GPIO %d)\n", pin);
+
+ if (!gpio_is_valid(pin))
+ return -EINVAL;
+
+ ret = gpio_request(pin, "pca953x interrupt");
+ if (ret)
+ return ret;
+
+ return gpio_to_irq(pin);
+}
+#endif
+
static const struct acpi_device_id pca953x_acpi_ids[] = {
{ "INT3491", 16 | PCA953X_TYPE | PCA_LATCH_INT, },
{ }
@@ -772,6 +845,12 @@ static int pca953x_irq_setup(struct pca953x_chip *chip,
u8 reg_direction[MAX_BANK];
int ret, i;

+ if (dmi_first_match(pca953x_dmi_acpi_irq_info)) {
+ ret = pca953x_acpi_get_irq(&client->dev);
+ if (ret > 0)
+ client->irq = ret;
+ }
+
if (!client->irq)
return 0;

--
2.25.1


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