[PATCH v3 4/4] gpio: mb86s7x: enable ACPI support

Ard Biesheuvel
2019-05-27T11:27:33Z

Make the mb86s7x GPIO block discoverable via ACPI. In addition, add
support for ACPI GPIO interrupts routed via platform interrupts, by
wiring the two together via the to_irq() gpiochip callback.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
---
drivers/gpio/gpio-mb86s7x.c | 51 +++++++++++++++++---
1 file changed, 44 insertions(+), 7 deletions(-)

diff --git a/drivers/gpio/gpio-mb86s7x.c b/drivers/gpio/gpio-mb86s7x.c
index 9308081e0a4a..64027f57a8aa 100644
--- a/drivers/gpio/gpio-mb86s7x.c
+++ b/drivers/gpio/gpio-mb86s7x.c
@@ -14,6 +14,7 @@
* GNU General Public License for more details.
*/

+#include <linux/acpi.h>
#include <linux/io.h>
#include <linux/init.h>
#include <linux/clk.h>
@@ -27,6 +28,8 @@
#include <linux/spinlock.h>
#include <linux/slab.h>

+#include "gpiolib.h"
+
/*
* Only first 8bits of a register correspond to each pin,
* so there are 4 registers for 32 pins.
@@ -143,6 +146,20 @@ static void mb86s70_gpio_set(struct gpio_chip *gc, unsigned gpio, int value)
spin_unlock_irqrestore(&gchip->lock, flags);
}

+static int mb86s70_gpio_to_irq(struct gpio_chip *gc, unsigned int offset)
+{
+ int irq, index;
+
+ for (index = 0;; index++) {
+ irq = platform_get_irq(to_platform_device(gc->parent), index);
+ if (irq <= 0)
+ break;
+ if (irq_get_irq_data(irq)->hwirq == offset)
+ return irq;
+ }
+ return -EINVAL;
+}
+
static int mb86s70_gpio_probe(struct platform_device *pdev)
{
struct mb86s70_gpio_chip *gchip;
@@ -158,13 +175,15 @@ static int mb86s70_gpio_probe(struct platform_device *pdev)
if (IS_ERR(gchip->base))
return PTR_ERR(gchip->base);

- gchip->clk = devm_clk_get(&pdev->dev, NULL);
- if (IS_ERR(gchip->clk))
- return PTR_ERR(gchip->clk);
+ if (!has_acpi_companion(&pdev->dev)) {
+ gchip->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(gchip->clk))
+ return PTR_ERR(gchip->clk);

- ret = clk_prepare_enable(gchip->clk);
- if (ret)
- return ret;
+ ret = clk_prepare_enable(gchip->clk);
+ if (ret)
+ return ret;
+ }

spin_lock_init(&gchip->lock);

@@ -180,19 +199,28 @@ static int mb86s70_gpio_probe(struct platform_device *pdev)
gchip->gc.parent = &pdev->dev;
gchip->gc.base = -1;

+ if (has_acpi_companion(&pdev->dev))
+ gchip->gc.to_irq = mb86s70_gpio_to_irq;
+
ret = gpiochip_add_data(&gchip->gc, gchip);
if (ret) {
dev_err(&pdev->dev, "couldn't register gpio driver\n");
clk_disable_unprepare(gchip->clk);
+ return ret;
}

- return ret;
+ if (has_acpi_companion(&pdev->dev))
+ acpi_gpiochip_request_interrupts(&gchip->gc);
+
+ return 0;
}

static int mb86s70_gpio_remove(struct platform_device *pdev)
{
struct mb86s70_gpio_chip *gchip = platform_get_drvdata(pdev);

+ if (has_acpi_companion(&pdev->dev))
+ acpi_gpiochip_free_interrupts(&gchip->gc);
gpiochip_remove(&gchip->gc);
clk_disable_unprepare(gchip->clk);

@@ -205,10 +233,19 @@ static const struct of_device_id mb86s70_gpio_dt_ids[] = {
};
MODULE_DEVICE_TABLE(of, mb86s70_gpio_dt_ids);

+#ifdef CONFIG_ACPI
+static const struct acpi_device_id mb86s70_gpio_acpi_ids[] = {
+ { "SCX0007" },
+ { /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(acpi, mb86s70_gpio_acpi_ids);
+#endif
+
static struct platform_driver mb86s70_gpio_driver = {
.driver = {
.name = "mb86s70-gpio",
.of_match_table = mb86s70_gpio_dt_ids,
+ .acpi_match_table = ACPI_PTR(mb86s70_gpio_acpi_ids),
},
.probe = mb86s70_gpio_probe,
.remove = mb86s70_gpio_remove,
--
2.20.1