[PATCH v3 14/25] pinctrl: qcom: ssbi-mpp: add support for hierarchical IRQ chip

[Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>]

ssbi-mpp did not have any irqchip support so consumers of this in
device tree would need to call gpio[d]_to_irq() in order to get the
proper IRQ on the underlying PMIC. IRQ chips in device tree should be
usable from the start without the consumer having to make an additional
call to get the proper IRQ on the parent. This patch adds hierarchical
IRQ chip support to the ssbi-mpp code to correct this issue.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>
---
 drivers/pinctrl/qcom/pinctrl-ssbi-mpp.c | 111 ++++++++++++++++++++----
 1 file changed, 93 insertions(+), 18 deletions(-)

diff --git a/drivers/pinctrl/qcom/pinctrl-ssbi-mpp.c b/drivers/pinctrl/qcom/pinctrl-ssbi-mpp.c
index a90cada1d657..842940594c4a 100644
--- a/drivers/pinctrl/qcom/pinctrl-ssbi-mpp.c
+++ b/drivers/pinctrl/qcom/pinctrl-ssbi-mpp.c
@@ -87,7 +87,6 @@
 /**
  * struct pm8xxx_pin_data - dynamic configuration for a pin
  * @reg:		address of the control register
- * @irq:		IRQ from the PMIC interrupt controller
  * @mode:		operating mode for the pin (digital, analog or current sink)
  * @input:		pin is input
  * @output:		pin is output
@@ -103,7 +102,6 @@
  */
 struct pm8xxx_pin_data {
 	unsigned reg;
-	int irq;
 
 	u8 mode;
 
@@ -126,6 +124,7 @@ struct pm8xxx_mpp {
 	struct regmap *regmap;
 	struct pinctrl_dev *pctrl;
 	struct gpio_chip chip;
+	struct irq_chip irq;
 
 	struct pinctrl_desc desc;
 	unsigned npins;
@@ -148,6 +147,8 @@ static const struct pin_config_item pm8xxx_conf_items[] = {
 #endif
 
 #define PM8XXX_MAX_MPPS	12
+#define PM8XXX_MPP_PHYSICAL_OFFSET    1
+
 static const char * const pm8xxx_groups[PM8XXX_MAX_MPPS] = {
 	"mpp1", "mpp2", "mpp3", "mpp4", "mpp5", "mpp6", "mpp7", "mpp8",
 	"mpp9", "mpp10", "mpp11", "mpp12",
@@ -492,12 +493,16 @@ static int pm8xxx_mpp_get(struct gpio_chip *chip, unsigned offset)
 	struct pm8xxx_mpp *pctrl = gpiochip_get_data(chip);
 	struct pm8xxx_pin_data *pin = pctrl->desc.pins[offset].drv_data;
 	bool state;
-	int ret;
+	int ret, irq;
 
 	if (!pin->input)
 		return !!pin->output_value;
 
-	ret = irq_get_irqchip_state(pin->irq, IRQCHIP_STATE_LINE_LEVEL, &state);
+	irq = chip->to_irq(chip, offset);
+	if (irq < 0)
+		return irq;
+
+	ret = irq_get_irqchip_state(irq, IRQCHIP_STATE_LINE_LEVEL, &state);
 	if (!ret)
 		ret = !!state;
 
@@ -524,18 +529,10 @@ static int pm8xxx_mpp_of_xlate(struct gpio_chip *chip,
 	if (flags)
 		*flags = gpio_desc->args[1];
 
-	return gpio_desc->args[0] - 1;
+	return gpio_desc->args[0] - PM8XXX_MPP_PHYSICAL_OFFSET;
 }
 
 
-static int pm8xxx_mpp_to_irq(struct gpio_chip *chip, unsigned offset)
-{
-	struct pm8xxx_mpp *pctrl = gpiochip_get_data(chip);
-	struct pm8xxx_pin_data *pin = pctrl->desc.pins[offset].drv_data;
-
-	return pin->irq;
-}
-
 #ifdef CONFIG_DEBUG_FS
 #include <linux/seq_file.h>
 
@@ -558,7 +555,7 @@ static void pm8xxx_mpp_dbg_show_one(struct seq_file *s,
 		"abus3",
 	};
 
-	seq_printf(s, " mpp%-2d:", offset + 1);
+	seq_printf(s, " mpp%-2d:", offset + PM8XXX_MPP_PHYSICAL_OFFSET);
 
 	switch (pin->mode) {
 	case PM8XXX_MPP_DIGITAL:
@@ -640,7 +637,6 @@ static const struct gpio_chip pm8xxx_mpp_template = {
 	.get = pm8xxx_mpp_get,
 	.set = pm8xxx_mpp_set,
 	.of_xlate = pm8xxx_mpp_of_xlate,
-	.to_irq = pm8xxx_mpp_to_irq,
 	.dbg_show = pm8xxx_mpp_dbg_show,
 	.owner = THIS_MODULE,
 };
@@ -732,6 +728,55 @@ static int pm8xxx_pin_populate(struct pm8xxx_mpp *pctrl,
 	return 0;
 }
 
+static int pm8xxx_mpp_domain_translate(struct irq_domain *domain,
+				   struct irq_fwspec *fwspec,
+				   unsigned long *hwirq,
+				   unsigned int *type)
+{
+	struct pm8xxx_mpp *pctrl = container_of(domain->host_data,
+						 struct pm8xxx_mpp, chip);
+
+	if (fwspec->param_count != 2 ||
+	    fwspec->param[0] < PM8XXX_MPP_PHYSICAL_OFFSET ||
+	    fwspec->param[0] > pctrl->chip.ngpio)
+		return -EINVAL;
+
+	*hwirq = fwspec->param[0] - PM8XXX_MPP_PHYSICAL_OFFSET;
+	*type = fwspec->param[1];
+
+	return 0;
+}
+
+static unsigned int pm8xxx_mpp_child_offset_to_irq(struct gpio_chip *chip,
+						   unsigned int offset)
+{
+	return offset + PM8XXX_MPP_PHYSICAL_OFFSET;
+}
+
+static int pm8821_mpp_child_to_parent_hwirq(struct gpio_chip *chip,
+					    unsigned int child_hwirq,
+					    unsigned int child_type,
+					    unsigned int *parent_hwirq,
+					    unsigned int *parent_type)
+{
+	*parent_hwirq = child_hwirq + 24;
+	*parent_type = child_type;
+
+	return 0;
+}
+
+static int pm8xxx_mpp_child_to_parent_hwirq(struct gpio_chip *chip,
+					    unsigned int child_hwirq,
+					    unsigned int child_type,
+					    unsigned int *parent_hwirq,
+					    unsigned int *parent_type)
+{
+	*parent_hwirq = child_hwirq + 0x80;
+	*parent_type = child_type;
+
+	return 0;
+}
+
 static const struct of_device_id pm8xxx_mpp_of_match[] = {
 	{ .compatible = "qcom,pm8018-mpp", .data = (void *) 6 },
 	{ .compatible = "qcom,pm8038-mpp", .data = (void *) 6 },
@@ -746,7 +791,10 @@ MODULE_DEVICE_TABLE(of, pm8xxx_mpp_of_match);
 static int pm8xxx_mpp_probe(struct platform_device *pdev)
 {
 	struct pm8xxx_pin_data *pin_data;
+	struct irq_domain *parent_domain;
+	struct device_node *parent_node;
 	struct pinctrl_pin_desc *pins;
+	struct gpio_irq_chip *girq;
 	struct pm8xxx_mpp *pctrl;
 	int ret;
 	int i;
@@ -783,9 +831,6 @@ static int pm8xxx_mpp_probe(struct platform_device *pdev)
 
 	for (i = 0; i < pctrl->desc.npins; i++) {
 		pin_data[i].reg = SSBI_REG_ADDR_MPP(i);
-		pin_data[i].irq = platform_get_irq(pdev, i);
-		if (pin_data[i].irq < 0)
-			return pin_data[i].irq;
 
 		ret = pm8xxx_pin_populate(pctrl, &pin_data[i]);
 		if (ret)
@@ -816,6 +861,36 @@ static int pm8xxx_mpp_probe(struct platform_device *pdev)
 	pctrl->chip.of_gpio_n_cells = 2;
 	pctrl->chip.label = dev_name(pctrl->dev);
 	pctrl->chip.ngpio = pctrl->npins;
+
+	parent_node = of_irq_find_parent(pctrl->dev->of_node);
+	if (!parent_node)
+		return -ENXIO;
+
+	parent_domain = irq_find_host(parent_node);
+	of_node_put(parent_node);
+	if (!parent_domain)
+		return -ENXIO;
+
+	pctrl->irq.name = "ssbi-mpp";
+	pctrl->irq.irq_mask_ack = irq_chip_mask_ack_parent;
+	pctrl->irq.irq_unmask = irq_chip_unmask_parent;
+	pctrl->irq.irq_set_type = irq_chip_set_type_parent;
+	pctrl->irq.flags = IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_SKIP_SET_WAKE;
+
+	girq = &pctrl->chip.irq;
+	girq->chip = &pctrl->irq;
+	girq->default_type = IRQ_TYPE_NONE;
+	girq->handler = handle_level_irq;
+	girq->fwnode = of_node_to_fwnode(pctrl->dev->of_node);
+	girq->parent_domain = parent_domain;
+	if (of_device_is_compatible(pdev->dev.of_node, "qcom,pm8821-mpp"))
+		girq->child_to_parent_hwirq = pm8821_mpp_child_to_parent_hwirq;
+	else
+		girq->child_to_parent_hwirq = pm8xxx_mpp_child_to_parent_hwirq;
+	girq->populate_parent_alloc_arg = gpiochip_populate_parent_fwspec_twocell;
+	girq->child_offset_to_irq = pm8xxx_mpp_child_offset_to_irq;
+	girq->child_irq_domain_ops.translate = pm8xxx_mpp_domain_translate;
+
 	ret = gpiochip_add_data(&pctrl->chip, pctrl);
 	if (ret) {
 		dev_err(&pdev->dev, "failed register gpiochip\n");
-- 
2.30.2