GPIO fixes for the v5.4 series

The fixes pertain to a problem with initializing the Intel GPIO
 irqchips when adding gpiochips, Andy fixed it up elegantly by
 adding a hardware initialization callback to the struct
 gpio_irq_chip so let's use this. Tested and verified on the
 target hardware.
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Merge tag 'gpio-v5.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

Pull GPIO fixes from Linus Walleij:
 "The fixes pertain to a problem with initializing the Intel GPIO
  irqchips when adding gpiochips.

  Andy fixed it up elegantly by adding a hardware initialization
  callback to the struct gpio_irq_chip so let's use this. Tested and
  verified on the target hardware"

* tag 'gpio-v5.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio:
  gpio: lynxpoint: set default handler to be handle_bad_irq()
  gpio: merrifield: Move hardware initialization to callback
  gpio: lynxpoint: Move hardware initialization to callback
  gpio: intel-mid: Move hardware initialization to callback
  gpiolib: Initialize the hardware with a callback
  gpio: merrifield: Restore use of irq_base

drivers/gpio/gpio-intel-mid.c

@@ -293,8 +293,9 @@ static void intel_mid_irq_handler(struct irq_desc *desc)
 	chip->irq_eoi(data);
 }
 
-static void intel_mid_irq_init_hw(struct intel_mid_gpio *priv)
+static int intel_mid_irq_init_hw(struct gpio_chip *chip)
 {
+	struct intel_mid_gpio *priv = gpiochip_get_data(chip);
 	void __iomem *reg;
 	unsigned base;
 
@@ -309,6 +310,8 @@ static void intel_mid_irq_init_hw(struct intel_mid_gpio *priv)
 		reg = gpio_reg(&priv->chip, base, GEDR);
 		writel(~0, reg);
 	}
+
+	return 0;
 }
 
 static int __maybe_unused intel_gpio_runtime_idle(struct device *dev)
@@ -372,6 +375,7 @@ static int intel_gpio_probe(struct pci_dev *pdev,
 
 	girq = &priv->chip.irq;
 	girq->chip = &intel_mid_irqchip;
+	girq->init_hw = intel_mid_irq_init_hw;
 	girq->parent_handler = intel_mid_irq_handler;
 	girq->num_parents = 1;
 	girq->parents = devm_kcalloc(&pdev->dev, girq->num_parents,
@@ -384,9 +388,8 @@ static int intel_gpio_probe(struct pci_dev *pdev,
 	girq->default_type = IRQ_TYPE_NONE;
 	girq->handler = handle_simple_irq;
 
-	intel_mid_irq_init_hw(priv);
-
 	pci_set_drvdata(pdev, priv);
+
 	retval = devm_gpiochip_add_data(&pdev->dev, &priv->chip, priv);
 	if (retval) {
 		dev_err(&pdev->dev, "gpiochip_add error %d\n", retval);

drivers/gpio/gpio-lynxpoint.c

@@ -294,8 +294,9 @@ static struct irq_chip lp_irqchip = {
 	.flags = IRQCHIP_SKIP_SET_WAKE,
 };
 
-static void lp_gpio_irq_init_hw(struct lp_gpio *lg)
+static int lp_gpio_irq_init_hw(struct gpio_chip *chip)
 {
+	struct lp_gpio *lg = gpiochip_get_data(chip);
 	unsigned long reg;
 	unsigned base;
 
@@ -307,6 +308,8 @@ static void lp_gpio_irq_init_hw(struct lp_gpio *lg)
 		reg = lp_gpio_reg(&lg->chip, base, LP_INT_STAT);
 		outl(0xffffffff, reg);
 	}
+
+	return 0;
 }
 
 static int lp_gpio_probe(struct platform_device *pdev)
@@ -364,6 +367,7 @@ static int lp_gpio_probe(struct platform_device *pdev)
 
 		girq = &gc->irq;
 		girq->chip = &lp_irqchip;
+		girq->init_hw = lp_gpio_irq_init_hw;
 		girq->parent_handler = lp_gpio_irq_handler;
 		girq->num_parents = 1;
 		girq->parents = devm_kcalloc(&pdev->dev, girq->num_parents,
@@ -373,9 +377,7 @@ static int lp_gpio_probe(struct platform_device *pdev)
 			return -ENOMEM;
 		girq->parents[0] = (unsigned)irq_rc->start;
 		girq->default_type = IRQ_TYPE_NONE;
-		girq->handler = handle_simple_irq;
+		girq->handler = handle_bad_irq;
-
-		lp_gpio_irq_init_hw(lg);
 	}
 
 	ret = devm_gpiochip_add_data(dev, gc, lg);

drivers/gpio/gpio-merrifield.c

@@ -362,8 +362,9 @@ static void mrfld_irq_handler(struct irq_desc *desc)
 	chained_irq_exit(irqchip, desc);
 }
 
-static void mrfld_irq_init_hw(struct mrfld_gpio *priv)
+static int mrfld_irq_init_hw(struct gpio_chip *chip)
 {
+	struct mrfld_gpio *priv = gpiochip_get_data(chip);
 	void __iomem *reg;
 	unsigned int base;
 
@@ -375,6 +376,8 @@ static void mrfld_irq_init_hw(struct mrfld_gpio *priv)
 		reg = gpio_reg(&priv->chip, base, GFER);
 		writel(0, reg);
 	}
+
+	return 0;
 }
 
 static const char *mrfld_gpio_get_pinctrl_dev_name(struct mrfld_gpio *priv)
@@ -447,6 +450,7 @@ static int mrfld_gpio_probe(struct pci_dev *pdev, const struct pci_device_id *id
 
 	girq = &priv->chip.irq;
 	girq->chip = &mrfld_irqchip;
+	girq->init_hw = mrfld_irq_init_hw;
 	girq->parent_handler = mrfld_irq_handler;
 	girq->num_parents = 1;
 	girq->parents = devm_kcalloc(&pdev->dev, girq->num_parents,
@@ -455,11 +459,10 @@ static int mrfld_gpio_probe(struct pci_dev *pdev, const struct pci_device_id *id
 	if (!girq->parents)
 		return -ENOMEM;
 	girq->parents[0] = pdev->irq;
+	girq->first = irq_base;
 	girq->default_type = IRQ_TYPE_NONE;
 	girq->handler = handle_bad_irq;
 
-	mrfld_irq_init_hw(priv);
-
 	pci_set_drvdata(pdev, priv);
 	retval = devm_gpiochip_add_data(&pdev->dev, &priv->chip, priv);
 	if (retval) {

drivers/gpio/gpiolib.c

@@ -86,6 +86,7 @@ static int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
 				struct lock_class_key *lock_key,
 				struct lock_class_key *request_key);
 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip);
+static int gpiochip_irqchip_init_hw(struct gpio_chip *gpiochip);
 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip);
 static void gpiochip_irqchip_free_valid_mask(struct gpio_chip *gpiochip);
 
@@ -1406,6 +1407,10 @@ int gpiochip_add_data_with_key(struct gpio_chip *chip, void *data,
 
 	machine_gpiochip_add(chip);
 
+	ret = gpiochip_irqchip_init_hw(chip);
+	if (ret)
+		goto err_remove_acpi_chip;
+
 	ret = gpiochip_irqchip_init_valid_mask(chip);
 	if (ret)
 		goto err_remove_acpi_chip;
@@ -1622,6 +1627,16 @@ static struct gpio_chip *find_chip_by_name(const char *name)
  * The following is irqchip helper code for gpiochips.
  */
 
+static int gpiochip_irqchip_init_hw(struct gpio_chip *gc)
+{
+	struct gpio_irq_chip *girq = &gc->irq;
+
+	if (!girq->init_hw)
+		return 0;
+
+	return girq->init_hw(gc);
+}
+
 static int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gc)
 {
 	struct gpio_irq_chip *girq = &gc->irq;
@@ -2446,8 +2461,13 @@ static inline int gpiochip_add_irqchip(struct gpio_chip *gpiochip,
 {
 	return 0;
 }
-
 static void gpiochip_irqchip_remove(struct gpio_chip *gpiochip) {}
+
+static inline int gpiochip_irqchip_init_hw(struct gpio_chip *gpiochip)
+{
+	return 0;
+}
+
 static inline int gpiochip_irqchip_init_valid_mask(struct gpio_chip *gpiochip)
 {
 	return 0;

include/linux/gpio/driver.h

@@ -201,6 +201,14 @@ struct gpio_irq_chip {
 	 */
 	bool threaded;
 
+	/**
+	 * @init_hw: optional routine to initialize hardware before
+	 * an IRQ chip will be added. This is quite useful when
+	 * a particular driver wants to clear IRQ related registers
+	 * in order to avoid undesired events.
+	 */
+	int (*init_hw)(struct gpio_chip *chip);
+
 	/**
 	 * @init_valid_mask: optional routine to initialize @valid_mask, to be
 	 * used if not all GPIO lines are valid interrupts. Sometimes some