[PATCH] pinctrl: cherryview: Add quirk with custom translation of ACPI GPIO numbers

[Michal Stanek <mst@xxxxxxxxxxxx>]

Dropping custom Linux GPIO translation caused some Intel_Strago based Chromebooks
with old firmware to detect GPIOs incorrectly. Add quirk which restores some code removed by
commit 03c4749dd6c7ff94 ("gpio / ACPI: Drop unnecessary ACPI GPIO to Linux GPIO translation").

Fixes: 03c4749dd6c7ff94 ("gpio / ACPI: Drop unnecessary ACPI GPIO to Linux GPIO translation")
Cc: <stable@xxxxxxxxxxxxxxx>
Reported-by: Alex Levin <levinale@xxxxxxxxxxxx>
Signed-off-by: Michal Stanek <mst@xxxxxxxxxxxx>
---
 drivers/gpio/gpiolib-acpi.c                | 102 ++++++++++++++++++++-
 drivers/pinctrl/intel/pinctrl-cherryview.c |  63 ++++++++++---
 2 files changed, 150 insertions(+), 15 deletions(-)

diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
index 31fee5e918b7..b5358facf3fb 100644
--- a/drivers/gpio/gpiolib-acpi.c
+++ b/drivers/gpio/gpiolib-acpi.c
@@ -23,6 +23,7 @@
 
 #define QUIRK_NO_EDGE_EVENTS_ON_BOOT		0x01l
 #define QUIRK_NO_WAKEUP				0x02l
+#define QUIRK_NEED_ACPI_GPIO_TRANSLATION	0x04l
 
 static int run_edge_events_on_boot = -1;
 module_param(run_edge_events_on_boot, int, 0444);
@@ -34,6 +35,11 @@ module_param(honor_wakeup, int, 0444);
 MODULE_PARM_DESC(honor_wakeup,
 		 "Honor the ACPI wake-capable flag: 0=no, 1=yes, -1=auto");
 
+static int need_acpi_gpio_translation = -1;
+module_param(need_acpi_gpio_translation, int, 0444);
+MODULE_PARM_DESC(need_acpi_gpio_translation,
+		 "Do custom ACPI GPIO number translation: 0=no, 1=yes, -1=auto");
+
 /**
  * struct acpi_gpio_event - ACPI GPIO event handler data
  *
@@ -98,6 +104,62 @@ 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;
+
+	/* Only do translation on selected platforms */
+	if (!need_acpi_gpio_translation)
+		return pin;
+
+	/* 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 int 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")
@@ -113,6 +175,7 @@ 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))
@@ -122,7 +185,11 @@ static struct gpio_desc *acpi_get_gpiod(char *path, int pin)
 	if (!chip)
 		return ERR_PTR(-EPROBE_DEFER);
 
-	return gpiochip_get_desc(chip, pin);
+	offset = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, pin);
+	if (offset < 0)
+		return ERR_PTR(offset);
+
+	return gpiochip_get_desc(chip, offset);
 }
 
 static irqreturn_t acpi_gpio_irq_handler(int irq, void *data)
@@ -236,6 +303,10 @@ static acpi_status acpi_gpiochip_alloc_event(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",
 					 GPIO_ACTIVE_HIGH, GPIOD_IN);
 	if (IS_ERR(desc)) {
@@ -958,6 +1029,12 @@ 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;
@@ -1086,7 +1163,11 @@ acpi_gpiochip_parse_own_gpio(struct acpi_gpio_chip *achip,
 	if (ret < 0)
 		return ERR_PTR(ret);
 
-	desc = gpiochip_get_desc(chip, gpios[0]);
+	ret = acpi_gpiochip_pin_to_gpio_offset(chip->gpiodev, gpios[0]);
+	if (ret < 0)
+		return ERR_PTR(ret);
+
+	desc = gpiochip_get_desc(chip, ret);
 	if (IS_ERR(desc))
 		return desc;
 
@@ -1360,6 +1441,17 @@ static const struct dmi_system_id gpiolib_acpi_quirks[] = {
 		},
 		.driver_data = (void *)QUIRK_NO_WAKEUP,
 	},
+	{
+		/*
+		 * Some Braswell based Google Chromebooks need custom ACPI GPIO
+		 * number translation due to hardcoded GPIO numbers in firmware.
+		 */
+		.matches = {
+		       DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
+		       DMI_MATCH(DMI_PRODUCT_FAMILY, "Intel_Strago"),
+		},
+		.driver_data = (void *)QUIRK_NEED_ACPI_GPIO_TRANSLATION,
+	},
 	{} /* Terminating entry */
 };
 
@@ -1385,6 +1477,12 @@ static int acpi_gpio_setup_params(void)
 		else
 			honor_wakeup = 1;
 	}
+	if (need_acpi_gpio_translation < 0) {
+		if (quirks & QUIRK_NEED_ACPI_GPIO_TRANSLATION)
+			need_acpi_gpio_translation = 1;
+		else
+			need_acpi_gpio_translation = 0;
+	}
 
 	return 0;
 }
diff --git a/drivers/pinctrl/intel/pinctrl-cherryview.c b/drivers/pinctrl/intel/pinctrl-cherryview.c
index 4c74fdde576d..dd190ac6b11c 100644
--- a/drivers/pinctrl/intel/pinctrl-cherryview.c
+++ b/drivers/pinctrl/intel/pinctrl-cherryview.c
@@ -119,6 +119,7 @@ struct chv_gpio_pinrange {
  * @nfunctions: Number of functions
  * @gpio_ranges: An array of GPIO ranges in this community
  * @ngpio_ranges: Number of GPIO ranges
+ * @ngpios: Total number of GPIOs in this community
  * @nirqs: Total number of IRQs this community can generate
  * @acpi_space_id: An address space ID for ACPI OpRegion handler
  */
@@ -132,6 +133,7 @@ struct chv_community {
 	size_t nfunctions;
 	const struct chv_gpio_pinrange *gpio_ranges;
 	size_t ngpio_ranges;
+	size_t ngpios;
 	size_t nirqs;
 	acpi_adr_space_type acpi_space_id;
 };
@@ -380,6 +382,7 @@ static const struct chv_community southwest_community = {
 	.nfunctions = ARRAY_SIZE(southwest_functions),
 	.gpio_ranges = southwest_gpio_ranges,
 	.ngpio_ranges = ARRAY_SIZE(southwest_gpio_ranges),
+	.ngpios = ARRAY_SIZE(southwest_pins),
 	/*
 	 * Southwest community can generate GPIO interrupts only for the
 	 * first 8 interrupts. The upper half (8-15) can only be used to
@@ -469,6 +472,7 @@ static const struct chv_community north_community = {
 	.npins = ARRAY_SIZE(north_pins),
 	.gpio_ranges = north_gpio_ranges,
 	.ngpio_ranges = ARRAY_SIZE(north_gpio_ranges),
+	.ngpios = ARRAY_SIZE(north_pins),
 	/*
 	 * North community can generate GPIO interrupts only for the first
 	 * 8 interrupts. The upper half (8-15) can only be used to trigger
@@ -517,6 +521,7 @@ static const struct chv_community east_community = {
 	.npins = ARRAY_SIZE(east_pins),
 	.gpio_ranges = east_gpio_ranges,
 	.ngpio_ranges = ARRAY_SIZE(east_gpio_ranges),
+	.ngpios = ARRAY_SIZE(east_pins),
 	.nirqs = 16,
 	.acpi_space_id = 0x93,
 };
@@ -643,6 +648,7 @@ static const struct chv_community southeast_community = {
 	.nfunctions = ARRAY_SIZE(southeast_functions),
 	.gpio_ranges = southeast_gpio_ranges,
 	.ngpio_ranges = ARRAY_SIZE(southeast_gpio_ranges),
+	.ngpios = ARRAY_SIZE(southeast_pins),
 	.nirqs = 16,
 	.acpi_space_id = 0x94,
 };
@@ -1236,14 +1242,39 @@ static struct pinctrl_desc chv_pinctrl_desc = {
 	.owner = THIS_MODULE,
 };
 
+static const struct dmi_system_id need_acpi_gpio_translation[] = {
+	{
+		/*
+		 * Some Braswell based Google Chromebooks need custom ACPI GPIO
+		 * number translation due to hardcoded GPIO numbers in firmware.
+		 */
+		.ident = "Intel_Strago based Chromebooks (All models)",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "GOOGLE"),
+			DMI_MATCH(DMI_PRODUCT_FAMILY, "Intel_Strago"),
+		},
+	},
+};
+
+static unsigned int chv_gpio_offset_to_pin(struct chv_pinctrl *pctrl,
+				      unsigned int offset)
+{
+	/* Mapping is not 1:1 on some platforms */
+	if (dmi_check_system(need_acpi_gpio_translation))
+		return pctrl->community->pins[offset].number;
+	else
+		return offset;
+}
+
 static int chv_gpio_get(struct gpio_chip *chip, unsigned int offset)
 {
 	struct chv_pinctrl *pctrl = gpiochip_get_data(chip);
+	unsigned int pin = chv_gpio_offset_to_pin(pctrl, offset);
 	unsigned long flags;
 	u32 ctrl0, cfg;
 
 	raw_spin_lock_irqsave(&chv_lock, flags);
-	ctrl0 = readl(chv_padreg(pctrl, offset, CHV_PADCTRL0));
+	ctrl0 = readl(chv_padreg(pctrl, pin, CHV_PADCTRL0));
 	raw_spin_unlock_irqrestore(&chv_lock, flags);
 
 	cfg = ctrl0 & CHV_PADCTRL0_GPIOCFG_MASK;
@@ -1257,13 +1288,14 @@ static int chv_gpio_get(struct gpio_chip *chip, unsigned int offset)
 static void chv_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
 {
 	struct chv_pinctrl *pctrl = gpiochip_get_data(chip);
+	unsigned int pin = chv_gpio_offset_to_pin(pctrl, offset);
 	unsigned long flags;
 	void __iomem *reg;
 	u32 ctrl0;
 
 	raw_spin_lock_irqsave(&chv_lock, flags);
 
-	reg = chv_padreg(pctrl, offset, CHV_PADCTRL0);
+	reg = chv_padreg(pctrl, pin, CHV_PADCTRL0);
 	ctrl0 = readl(reg);
 
 	if (value)
@@ -1279,11 +1311,12 @@ static void chv_gpio_set(struct gpio_chip *chip, unsigned int offset, int value)
 static int chv_gpio_get_direction(struct gpio_chip *chip, unsigned int offset)
 {
 	struct chv_pinctrl *pctrl = gpiochip_get_data(chip);
+	unsigned int pin = chv_gpio_offset_to_pin(pctrl, offset);
 	u32 ctrl0, direction;
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&chv_lock, flags);
-	ctrl0 = readl(chv_padreg(pctrl, offset, CHV_PADCTRL0));
+	ctrl0 = readl(chv_padreg(pctrl, pin, CHV_PADCTRL0));
 	raw_spin_unlock_irqrestore(&chv_lock, flags);
 
 	direction = ctrl0 & CHV_PADCTRL0_GPIOCFG_MASK;
@@ -1322,7 +1355,7 @@ static void chv_gpio_irq_ack(struct irq_data *d)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct chv_pinctrl *pctrl = gpiochip_get_data(gc);
-	int pin = irqd_to_hwirq(d);
+	unsigned int pin = chv_gpio_offset_to_pin(pctrl, irqd_to_hwirq(d));
 	u32 intr_line;
 
 	raw_spin_lock(&chv_lock);
@@ -1339,7 +1372,7 @@ static void chv_gpio_irq_mask_unmask(struct irq_data *d, bool mask)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct chv_pinctrl *pctrl = gpiochip_get_data(gc);
-	int pin = irqd_to_hwirq(d);
+	unsigned int pin = chv_gpio_offset_to_pin(pctrl, irqd_to_hwirq(d));
 	u32 value, intr_line;
 	unsigned long flags;
 
@@ -1384,7 +1417,8 @@ static unsigned chv_gpio_irq_startup(struct irq_data *d)
 	if (irqd_get_trigger_type(d) == IRQ_TYPE_NONE) {
 		struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 		struct chv_pinctrl *pctrl = gpiochip_get_data(gc);
-		unsigned int pin = irqd_to_hwirq(d);
+		unsigned int offset = irqd_to_hwirq(d);
+		unsigned int pin = chv_gpio_offset_to_pin(pctrl, offset);
 		irq_flow_handler_t handler;
 		unsigned long flags;
 		u32 intsel, value;
@@ -1402,7 +1436,7 @@ static unsigned chv_gpio_irq_startup(struct irq_data *d)
 
 		if (!pctrl->intr_lines[intsel]) {
 			irq_set_handler_locked(d, handler);
-			pctrl->intr_lines[intsel] = pin;
+			pctrl->intr_lines[intsel] = offset;
 		}
 		raw_spin_unlock_irqrestore(&chv_lock, flags);
 	}
@@ -1415,7 +1449,8 @@ static int chv_gpio_irq_type(struct irq_data *d, unsigned int type)
 {
 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
 	struct chv_pinctrl *pctrl = gpiochip_get_data(gc);
-	unsigned int pin = irqd_to_hwirq(d);
+	unsigned int offset = irqd_to_hwirq(d);
+	unsigned int pin = chv_gpio_offset_to_pin(pctrl, offset);
 	unsigned long flags;
 	u32 value;
 
@@ -1461,7 +1496,7 @@ static int chv_gpio_irq_type(struct irq_data *d, unsigned int type)
 	value &= CHV_PADCTRL0_INTSEL_MASK;
 	value >>= CHV_PADCTRL0_INTSEL_SHIFT;
 
-	pctrl->intr_lines[value] = pin;
+	pctrl->intr_lines[value] = offset;
 
 	if (type & IRQ_TYPE_EDGE_BOTH)
 		irq_set_handler_locked(d, handle_edge_irq);
@@ -1591,17 +1626,19 @@ static int chv_gpio_add_pin_ranges(struct gpio_chip *chip)
 	struct chv_pinctrl *pctrl = gpiochip_get_data(chip);
 	const struct chv_community *community = pctrl->community;
 	const struct chv_gpio_pinrange *range;
-	int ret, i;
+	int ret, i, offset;
 
-	for (i = 0; i < community->ngpio_ranges; i++) {
+	for (i = 0, offset = 0; i < community->ngpio_ranges; i++) {
 		range = &community->gpio_ranges[i];
 		ret = gpiochip_add_pin_range(chip, dev_name(pctrl->dev),
-					     range->base, range->base,
+					     offset, range->base,
 					     range->npins);
 		if (ret) {
 			dev_err(pctrl->dev, "failed to add GPIO pin range\n");
 			return ret;
 		}
+
+		offset += range->npins;
 	}
 
 	return 0;
@@ -1617,7 +1654,7 @@ static int chv_gpio_probe(struct chv_pinctrl *pctrl, int irq)
 
 	*chip = chv_gpio_chip;
 
-	chip->ngpio = community->pins[community->npins - 1].number + 1;
+	chip->ngpio = community->ngpios;
 	chip->label = dev_name(pctrl->dev);
 	chip->add_pin_ranges = chv_gpio_add_pin_ranges;
 	chip->parent = pctrl->dev;
-- 
2.17.1