[PATCH 6/6] gpio: macsmc: Add IRQ support

[Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>]

From: Hector Martin <marcan@xxxxxxxxx>

Add IRQ support to the macsmc driver. This patch has updates from Joey
Gouly and Russell King.

Signed-off-by: Hector Martin <marcan@xxxxxxxxx>
Signed-off-by: Russell King (Oracle) <rmk+kernel@xxxxxxxxxxxxxxx>
---
 drivers/gpio/gpio-macsmc.c | 156 +++++++++++++++++++++++++++++++++++++
 1 file changed, 156 insertions(+)

diff --git a/drivers/gpio/gpio-macsmc.c b/drivers/gpio/gpio-macsmc.c
index ff9950afb69a..939e2dc33c6f 100644
--- a/drivers/gpio/gpio-macsmc.c
+++ b/drivers/gpio/gpio-macsmc.c
@@ -10,6 +10,7 @@
 #include <linux/bitmap.h>
 #include <linux/device.h>
 #include <linux/gpio/driver.h>
+#include <linux/irq.h>
 #include <linux/mfd/core.h>
 #include <linux/mfd/macsmc.h>
 
@@ -68,10 +69,20 @@
  *   3 = ?
  */
 
+#define SMC_EV_GPIO 0x7202
+
 struct macsmc_gpio {
 	struct device *dev;
 	struct apple_smc *smc;
 	struct gpio_chip gc;
+	struct notifier_block nb;
+
+	struct mutex irq_mutex;
+	DECLARE_BITMAP(irq_supported, MAX_GPIO);
+	DECLARE_BITMAP(irq_enable_shadow, MAX_GPIO);
+	DECLARE_BITMAP(irq_enable, MAX_GPIO);
+	u32 irq_mode_shadow[MAX_GPIO];
+	u32 irq_mode[MAX_GPIO];
 
 	int first_index;
 };
@@ -161,6 +172,7 @@ static int macsmc_gpio_init_valid_mask(struct gpio_chip *gc,
 	for (i = 0; i < count; i++) {
 		smc_key key;
 		int gpio_nr;
+		u32 val;
 		int ret = apple_smc_get_key_by_index(smcgp->smc, smcgp->first_index + i, &key);
 
 		if (ret < 0)
@@ -176,11 +188,143 @@ static int macsmc_gpio_init_valid_mask(struct gpio_chip *gc,
 		}
 
 		set_bit(gpio_nr, valid_mask);
+
+		/* Check for IRQ support */
+		ret = apple_smc_rw_u32(smcgp->smc, key, CMD_IRQ_MODE, &val);
+		if (!ret)
+			set_bit(gpio_nr, smcgp->irq_supported);
+	}
+
+	return 0;
+}
+
+static int macsmc_gpio_event(struct notifier_block *nb, unsigned long event, void *data)
+{
+	struct macsmc_gpio *smcgp = container_of(nb, struct macsmc_gpio, nb);
+	u16 type = event >> 16;
+	u8 offset = (event >> 8) & 0xff;
+	smc_key key = macsmc_gpio_key(offset);
+	unsigned long flags;
+        int ret;
+
+	if (type != SMC_EV_GPIO)
+		return NOTIFY_DONE;
+
+	if (offset > MAX_GPIO) {
+		dev_err(smcgp->dev, "GPIO event index %d out of range\n", offset);
+		return NOTIFY_BAD;
+	}
+
+	local_irq_save(flags);
+	ret = generic_handle_domain_irq(smcgp->gc.irq.domain, offset);
+	local_irq_restore(flags);
+
+	if (apple_smc_write_u32(smcgp->smc, key, CMD_IRQ_ACK | 1) < 0)
+		dev_err(smcgp->dev, "GPIO IRQ ack failed for %p4ch\n", &key);
+
+	return (ret == 0) ? NOTIFY_OK : NOTIFY_DONE;
+}
+
+static void macsmc_gpio_irq_enable(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct macsmc_gpio *smcgp = gpiochip_get_data(gc);
+
+	gpiochip_enable_irq(gc, irqd_to_hwirq(d));
+	set_bit(irqd_to_hwirq(d), smcgp->irq_enable_shadow);
+}
+
+static void macsmc_gpio_irq_disable(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct macsmc_gpio *smcgp = gpiochip_get_data(gc);
+
+	clear_bit(irqd_to_hwirq(d), smcgp->irq_enable_shadow);
+	gpiochip_disable_irq(gc, irqd_to_hwirq(d));
+}
+
+static int macsmc_gpio_irq_set_type(struct irq_data *d, unsigned int type)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct macsmc_gpio *smcgp = gpiochip_get_data(gc);
+	int offset = irqd_to_hwirq(d);
+	u32 mode;
+
+	if (!test_bit(offset, smcgp->irq_supported))
+		return -EINVAL;
+
+	switch (type & IRQ_TYPE_SENSE_MASK) {
+	case IRQ_TYPE_LEVEL_HIGH:
+		mode = IRQ_MODE_HIGH;
+		break;
+	case IRQ_TYPE_LEVEL_LOW:
+		mode = IRQ_MODE_LOW;
+		break;
+	case IRQ_TYPE_EDGE_RISING:
+		mode = IRQ_MODE_RISING;
+		break;
+	case IRQ_TYPE_EDGE_FALLING:
+		mode = IRQ_MODE_FALLING;
+		break;
+	case IRQ_TYPE_EDGE_BOTH:
+		mode = IRQ_MODE_BOTH;
+		break;
+	default:
+		return -EINVAL;
 	}
 
+	smcgp->irq_mode_shadow[offset] = mode;
 	return 0;
 }
 
+static void macsmc_gpio_irq_bus_lock(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct macsmc_gpio *smcgp = gpiochip_get_data(gc);
+
+	mutex_lock(&smcgp->irq_mutex);
+}
+
+static void macsmc_gpio_irq_bus_sync_unlock(struct irq_data *d)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+	struct macsmc_gpio *smcgp = gpiochip_get_data(gc);
+	smc_key key = macsmc_gpio_key(irqd_to_hwirq(d));
+	int offset = irqd_to_hwirq(d);
+	bool val;
+
+	if (smcgp->irq_mode_shadow[offset] != smcgp->irq_mode[offset]) {
+		u32 cmd = CMD_IRQ_MODE | smcgp->irq_mode_shadow[offset];
+		if (apple_smc_write_u32(smcgp->smc, key, cmd) < 0)
+			dev_err(smcgp->dev, "GPIO IRQ config failed for %p4ch = 0x%x\n", &key, cmd);
+		else
+			smcgp->irq_mode_shadow[offset] = smcgp->irq_mode[offset];
+	}
+
+	val = test_bit(offset, smcgp->irq_enable_shadow);
+	if (test_bit(offset, smcgp->irq_enable) != val) {
+		if (apple_smc_write_u32(smcgp->smc, key, CMD_IRQ_ENABLE | val) < 0)
+			dev_err(smcgp->dev, "GPIO IRQ en/disable failed for %p4ch\n", &key);
+		else
+			change_bit(offset, smcgp->irq_enable);
+	}
+
+	mutex_unlock(&smcgp->irq_mutex);
+}
+
+static const struct irq_chip macsmc_gpio_irqchip = {
+	.name			= "macsmc-pmu-gpio",
+	.irq_mask		= macsmc_gpio_irq_disable,
+	.irq_unmask		= macsmc_gpio_irq_enable,
+	.irq_set_type		= macsmc_gpio_irq_set_type,
+	.irq_bus_lock		= macsmc_gpio_irq_bus_lock,
+	.irq_bus_sync_unlock	= macsmc_gpio_irq_bus_sync_unlock,
+	.irq_set_type 		= macsmc_gpio_irq_set_type,
+	.flags 			= IRQCHIP_SET_TYPE_MASKED |
+					IRQCHIP_MASK_ON_SUSPEND | IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
 static int macsmc_gpio_probe(struct platform_device *pdev)
 {
 	struct macsmc_gpio *smcgp;
@@ -221,6 +365,18 @@ static int macsmc_gpio_probe(struct platform_device *pdev)
 	smcgp->gc.base = -1;
 	smcgp->gc.parent = &pdev->dev;
 
+	gpio_irq_chip_set_chip(&smcgp->gc.irq, &macsmc_gpio_irqchip);
+	smcgp->gc.irq.parent_handler = NULL;
+	smcgp->gc.irq.num_parents = 0;
+	smcgp->gc.irq.parents = NULL;
+	smcgp->gc.irq.default_type = IRQ_TYPE_NONE;
+	smcgp->gc.irq.handler = handle_simple_irq;
+
+	mutex_init(&smcgp->irq_mutex);
+
+	smcgp->nb.notifier_call = macsmc_gpio_event;
+	apple_smc_register_notifier(smc, &smcgp->nb);
+
 	return devm_gpiochip_add_data(&pdev->dev, &smcgp->gc, smcgp);
 }
 
-- 
2.30.2