gpio / ACPI: Drop unnecessary ACPI GPIO to Linux GPIO translation

We added acpi_gpiochip_pin_to_gpio_offset() because there was a need to
translate from ACPI GpioIo/GpioInt number to Linux GPIO number in the
Cherryview pinctrl driver. This translation is necessary because
Cherryview has gaps in the pin list and the driver used continuous GPIO
number space in Linux side as follows:

  created GPIO range 0->7 ==> INT33FF:03 PIN 0->7
  created GPIO range 8->19 ==> INT33FF:03 PIN 15->26
  created GPIO range 20->25 ==> INT33FF:03 PIN 30->35
  created GPIO range 26->33 ==> INT33FF:03 PIN 45->52
  created GPIO range 34->43 ==> INT33FF:03 PIN 60->69
  created GPIO range 44->54 ==> INT33FF:03 PIN 75->85

For example when ACPI GpioInt resource refers to GPIO 81 (SDMMC3_CD_B)
we translate from pin 81 to the corresponding Linux GPIO number, which
is 50. This number is then used when the GPIO is accessed through gpiolib.

It turns out, this is not necessary at all. We can just pass 1:1 mapping
between Linux GPIO numbers and pin numbers (including gaps) and the
pinctrl core handles all the details automatically:

  created GPIO range 0->7 ==> INT33FF:03 PIN 0->7
  created GPIO range 15->26 ==> INT33FF:03 PIN 15->26
  created GPIO range 30->35 ==> INT33FF:03 PIN 30->35
  created GPIO range 45->52 ==> INT33FF:03 PIN 45->52
  created GPIO range 60->69 ==> INT33FF:03 PIN 60->69
  created GPIO range 75->85 ==> INT33FF:03 PIN 75->85

Here GPIO 81 is exactly same than the hardware pin 81 (SDMMC3_CD_B).

As an added bonus this simplifies both the ACPI GPIO core code and the
Cherryview pinctrl driver.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 2 insertions, 73 deletions

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index eb4528c87c0b..b77c544bf7e2 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -58,58 +58,6 @@ static int acpi_gpiochip_find(struct gpio_chip *gc, void *data)
 	return ACPI_HANDLE(gc->parent) == data;
 }
 
-#ifdef CONFIG_PINCTRL
-/**
- * acpi_gpiochip_pin_to_gpio_offset() - translates ACPI GPIO to Linux GPIO
- * @gdev: GPIO device
- * @pin: ACPI GPIO pin number from GpioIo/GpioInt resource
- *
- * Function takes ACPI GpioIo/GpioInt pin number as a parameter and
- * translates it to a corresponding offset suitable to be passed to a
- * GPIO controller driver.
- *
- * Typically the returned offset is same as @pin, but if the GPIO
- * controller uses pin controller and the mapping is not contiguous the
- * offset might be different.
- */
-static int acpi_gpiochip_pin_to_gpio_offset(struct gpio_device *gdev, int pin)
-{
-	struct gpio_pin_range *pin_range;
-
-	/* If there are no ranges in this chip, use 1:1 mapping */
-	if (list_empty(&gdev->pin_ranges))
-		return pin;
-
-	list_for_each_entry(pin_range, &gdev->pin_ranges, node) {
-		const struct pinctrl_gpio_range *range = &pin_range->range;
-		int i;
-
-		if (range->pins) {
-			for (i = 0; i < range->npins; i++) {
-				if (range->pins[i] == pin)
-					return range->base + i - gdev->base;
-			}
-		} else {
-			if (pin >= range->pin_base &&
-			    pin < range->pin_base + range->npins) {
-				unsigned gpio_base;
-
-				gpio_base = range->base - gdev->base;
-				return gpio_base + pin - range->pin_base;
-			}
-		}
-	}
-
-	return -EINVAL;
-}
-#else
-static inline int acpi_gpiochip_pin_to_gpio_offset(struct gpio_device *gdev,
-						   int pin)
-{
-	return pin;
-}
-#endif
-
 /**
  * acpi_get_gpiod() - Translate ACPI GPIO pin to GPIO descriptor usable with GPIO API
  * @path:	ACPI GPIO controller full path name, (e.g. "\\_SB.GPO1")
@@ -125,7 +73,6 @@ static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
 	struct gpio_chip *chip;
 	acpi_handle handle;
 	acpi_status status;
-	int offset;
 
 	status = acpi_get_handle(NULL, path, &handle);
 	if (ACPI_FAILURE(status))
@@ -135,11 +82,7 @@ static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
 	if (!chip)
 		return ERR_PTR(-EPROBE_DEFER);
 
-	offset = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, pin);
-	if (offset < 0)
-		return ERR_PTR(offset);
-
-	return gpiochip_get_desc(chip, offset);
+	return gpiochip_get_desc(chip, pin);
 }
 
 static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
@@ -216,10 +159,6 @@ static acpi_status acpi_gpiochip_request_interrupt(struct acpi_resource *ares,
 	if (!handler)
 		return AE_OK;
 
-	pin = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, pin);
-	if (pin < 0)
-		return AE_BAD_PARAMETER;
-
 	desc = gpiochip_request_own_desc(chip, pin, "ACPI:Event");
 	if (IS_ERR(desc)) {
 		dev_err(chip->parent, "Failed to request GPIO\n");
@@ -852,12 +791,6 @@ acpi_gpio_adr_space_handler(u32 function, acpi_physical_address address,
 		struct gpio_desc *desc;
 		bool found;
 
-		pin = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, pin);
-		if (pin < 0) {
-			status = AE_BAD_PARAMETER;
-			goto out;
-		}
-
 		mutex_lock(&achip->conn_lock);
 
 		found = false;
@@ -990,11 +923,7 @@ static struct gpio_desc *acpi_gpiochip_parse_own_gpio(
 	if (ret < 0)
 		return ERR_PTR(ret);
 
-	ret = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, gpios[0]);
-	if (ret < 0)
-		return ERR_PTR(ret);
-
-	desc = gpiochip_get_desc(chip, ret);
+	desc = gpiochip_get_desc(chip, gpios[0]);
 	if (IS_ERR(desc))
 		return desc;