soc/tegra: pmc: Add wake event support

The power management controller has top-level controls that allow
certain interrupts (such as from the RTC or a subset of GPIOs) to
wake the system from sleep. Implement infrastructure to support
these wake events.

Signed-off-by: Thierry Reding <treding@nvidia.com>

drivers/soc/tegra/pmc.c

@@ -30,9 +30,12 @@
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/iopoll.h>
+#include <linux/irq.h>
+#include <linux/irqdomain.h>
 #include <linux/of.h>
 #include <linux/of_address.h>
 #include <linux/of_clk.h>
+#include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/pinctrl/pinctrl.h>
 #include <linux/pinctrl/pinconf.h>
@@ -49,6 +52,7 @@
 #include <soc/tegra/fuse.h>
 #include <soc/tegra/pmc.h>
 
+#include <dt-bindings/interrupt-controller/arm-gic.h>
 #include <dt-bindings/pinctrl/pinctrl-tegra-io-pad.h>
 
 #define PMC_CNTRL			0x0
@@ -126,6 +130,16 @@
 #define GPU_RG_CNTRL			0x2d4
 
 /* Tegra186 and later */
+#define WAKE_AOWAKE_CNTRL(x) (0x000 + ((x) << 2))
+#define WAKE_AOWAKE_CNTRL_LEVEL (1 << 3)
+#define WAKE_AOWAKE_MASK_W(x) (0x180 + ((x) << 2))
+#define WAKE_AOWAKE_MASK_R(x) (0x300 + ((x) << 2))
+#define WAKE_AOWAKE_STATUS_W(x) (0x30c + ((x) << 2))
+#define WAKE_AOWAKE_STATUS_R(x) (0x48c + ((x) << 2))
+#define WAKE_AOWAKE_TIER0_ROUTING(x) (0x4b4 + ((x) << 2))
+#define WAKE_AOWAKE_TIER1_ROUTING(x) (0x4c0 + ((x) << 2))
+#define WAKE_AOWAKE_TIER2_ROUTING(x) (0x4cc + ((x) << 2))
+
 #define WAKE_AOWAKE_CTRL 0x4f4
 #define  WAKE_AOWAKE_CTRL_INTR_POLARITY BIT(0)
 
@@ -158,6 +172,38 @@ struct tegra_pmc_regs {
 	unsigned int rst_level_mask;
 };
 
+struct tegra_wake_event {
+	const char *name;
+	unsigned int id;
+	unsigned int irq;
+	struct {
+		unsigned int instance;
+		unsigned int pin;
+	} gpio;
+};
+
+#define TEGRA_WAKE_IRQ(_name, _id, _irq)		\
+	{						\
+		.name = _name,				\
+		.id = _id,				\
+		.irq = _irq,				\
+		.gpio = {				\
+			.instance = UINT_MAX,		\
+			.pin = UINT_MAX,		\
+		},					\
+	}
+
+#define TEGRA_WAKE_GPIO(_name, _id, _instance, _pin)	\
+	{						\
+		.name = _name,				\
+		.id = _id,				\
+		.irq = 0,				\
+		.gpio = {				\
+			.instance = _instance,		\
+			.pin = _pin,			\
+		},					\
+	}
+
 struct tegra_pmc_soc {
 	unsigned int num_powergates;
 	const char *const *powergates;
@@ -185,6 +231,9 @@ struct tegra_pmc_soc {
 	unsigned int num_reset_sources;
 	const char * const *reset_levels;
 	unsigned int num_reset_levels;
+
+	const struct tegra_wake_event *wake_events;
+	unsigned int num_wake_events;
 };
 
 static const char * const tegra186_reset_sources[] = {
@@ -271,6 +320,9 @@ struct tegra_pmc {
 	struct mutex powergates_lock;
 
 	struct pinctrl_dev *pctl_dev;
+
+	struct irq_domain *domain;
+	struct irq_chip irq;
 };
 
 static struct tegra_pmc *pmc = &(struct tegra_pmc) {
@@ -1602,6 +1654,175 @@ static void tegra_pmc_reset_sysfs_init(struct tegra_pmc *pmc)
 	}
 }
 
+static int tegra_pmc_irq_translate(struct irq_domain *domain,
+				   struct irq_fwspec *fwspec,
+				   unsigned long *hwirq,
+				   unsigned int *type)
+{
+	if (WARN_ON(fwspec->param_count < 2))
+		return -EINVAL;
+
+	*hwirq = fwspec->param[0];
+	*type = fwspec->param[1];
+
+	return 0;
+}
+
+static int tegra_pmc_irq_alloc(struct irq_domain *domain, unsigned int virq,
+			       unsigned int num_irqs, void *data)
+{
+	struct tegra_pmc *pmc = domain->host_data;
+	const struct tegra_pmc_soc *soc = pmc->soc;
+	struct irq_fwspec *fwspec = data;
+	unsigned int i;
+	int err = 0;
+
+	for (i = 0; i < soc->num_wake_events; i++) {
+		const struct tegra_wake_event *event = &soc->wake_events[i];
+
+		if (fwspec->param_count == 2) {
+			struct irq_fwspec spec;
+
+			if (event->id != fwspec->param[0])
+				continue;
+
+			err = irq_domain_set_hwirq_and_chip(domain, virq,
+							    event->id,
+							    &pmc->irq, pmc);
+			if (err < 0)
+				break;
+
+			spec.fwnode = &pmc->dev->of_node->fwnode;
+			spec.param_count = 3;
+			spec.param[0] = GIC_SPI;
+			spec.param[1] = event->irq;
+			spec.param[2] = fwspec->param[1];
+
+			err = irq_domain_alloc_irqs_parent(domain, virq,
+							   num_irqs, &spec);
+
+			break;
+		}
+
+		if (fwspec->param_count == 3) {
+			if (event->gpio.instance != fwspec->param[0] ||
+			    event->gpio.pin != fwspec->param[1])
+				continue;
+
+			err = irq_domain_set_hwirq_and_chip(domain, virq,
+							    event->id,
+							    &pmc->irq, pmc);
+
+			break;
+		}
+	}
+
+	if (i == soc->num_wake_events)
+		err = irq_domain_set_hwirq_and_chip(domain, virq, ULONG_MAX,
+						    &pmc->irq, pmc);
+
+	return err;
+}
+
+static const struct irq_domain_ops tegra_pmc_irq_domain_ops = {
+	.translate = tegra_pmc_irq_translate,
+	.alloc = tegra_pmc_irq_alloc,
+};
+
+static int tegra_pmc_irq_set_wake(struct irq_data *data, unsigned int on)
+{
+	struct tegra_pmc *pmc = irq_data_get_irq_chip_data(data);
+	unsigned int offset, bit;
+	u32 value;
+
+	offset = data->hwirq / 32;
+	bit = data->hwirq % 32;
+
+	/* clear wake status */
+	writel(0x1, pmc->wake + WAKE_AOWAKE_STATUS_W(data->hwirq));
+
+	/* route wake to tier 2 */
+	value = readl(pmc->wake + WAKE_AOWAKE_TIER2_ROUTING(offset));
+
+	if (!on)
+		value &= ~(1 << bit);
+	else
+		value |= 1 << bit;
+
+	writel(value, pmc->wake + WAKE_AOWAKE_TIER2_ROUTING(offset));
+
+	/* enable wakeup event */
+	writel(!!on, pmc->wake + WAKE_AOWAKE_MASK_W(data->hwirq));
+
+	return 0;
+}
+
+static int tegra_pmc_irq_set_type(struct irq_data *data, unsigned int type)
+{
+	struct tegra_pmc *pmc = irq_data_get_irq_chip_data(data);
+	u32 value;
+
+	if (data->hwirq == ULONG_MAX)
+		return 0;
+
+	value = readl(pmc->wake + WAKE_AOWAKE_CNTRL(data->hwirq));
+
+	switch (type) {
+	case IRQ_TYPE_EDGE_RISING:
+	case IRQ_TYPE_LEVEL_HIGH:
+		value |= WAKE_AOWAKE_CNTRL_LEVEL;
+		break;
+
+	case IRQ_TYPE_EDGE_FALLING:
+	case IRQ_TYPE_LEVEL_LOW:
+		value &= ~WAKE_AOWAKE_CNTRL_LEVEL;
+		break;
+
+	case IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING:
+		value ^= WAKE_AOWAKE_CNTRL_LEVEL;
+		break;
+
+	default:
+		return -EINVAL;
+	}
+
+	writel(value, pmc->wake + WAKE_AOWAKE_CNTRL(data->hwirq));
+
+	return 0;
+}
+
+static int tegra_pmc_irq_init(struct tegra_pmc *pmc)
+{
+	struct irq_domain *parent = NULL;
+	struct device_node *np;
+
+	np = of_irq_find_parent(pmc->dev->of_node);
+	if (np) {
+		parent = irq_find_host(np);
+		of_node_put(np);
+	}
+
+	if (!parent)
+		return 0;
+
+	pmc->irq.name = dev_name(pmc->dev);
+	pmc->irq.irq_mask = irq_chip_mask_parent;
+	pmc->irq.irq_unmask = irq_chip_unmask_parent;
+	pmc->irq.irq_eoi = irq_chip_eoi_parent;
+	pmc->irq.irq_set_affinity = irq_chip_set_affinity_parent;
+	pmc->irq.irq_set_type = tegra_pmc_irq_set_type;
+	pmc->irq.irq_set_wake = tegra_pmc_irq_set_wake;
+
+	pmc->domain = irq_domain_add_hierarchy(parent, 0, 96, pmc->dev->of_node,
+					       &tegra_pmc_irq_domain_ops, pmc);
+	if (!pmc->domain) {
+		dev_err(pmc->dev, "failed to allocate domain\n");
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
 static int tegra_pmc_probe(struct platform_device *pdev)
 {
 	void __iomem *base;
@@ -1690,6 +1911,10 @@ static int tegra_pmc_probe(struct platform_device *pdev)
 	if (err)
 		goto cleanup_restart_handler;
 
+	err = tegra_pmc_irq_init(pmc);
+	if (err < 0)
+		goto cleanup_restart_handler;
+
 	mutex_lock(&pmc->powergates_lock);
 	iounmap(pmc->base);
 	pmc->base = base;