1 files changed, 176 insertions, 84 deletions

diff --git a/drivers/gpio/gpio-tqmx86.c b/drivers/gpio/gpio-tqmx86.c
index 5022e0ad0fae..eedfc0e371e3 100644
--- a/drivers/gpio/gpio-tqmx86.c
+++ b/drivers/gpio/gpio-tqmx86.c
@@ -6,6 +6,7 @@
  *   Vadim V.Vlasov <vvlasov@dev.rtsoft.ru>
  */
 
+#include <linux/bitmap.h>
 #include <linux/bitops.h>
 #include <linux/errno.h>
 #include <linux/gpio/driver.h>
@@ -15,6 +16,7 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/seq_file.h>
 #include <linux/slab.h>
 
 #define TQMX86_NGPIO	8
@@ -27,18 +29,30 @@
 #define TQMX86_GPIIC	3	/* GPI Interrupt Configuration Register */
 #define TQMX86_GPIIS	4	/* GPI Interrupt Status Register */
 
-#define TQMX86_GPII_FALLING	BIT(0)
-#define TQMX86_GPII_RISING	BIT(1)
-#define TQMX86_GPII_MASK	(BIT(0) | BIT(1))
-#define TQMX86_GPII_BITS	2
+/*
+ * NONE, FALLING and RISING use the same bit patterns that can be programmed to
+ * the GPII register (after passing them to the TQMX86_GPII_ macros to shift
+ * them to the right position)
+ */
+#define TQMX86_INT_TRIG_NONE	0
+#define TQMX86_INT_TRIG_FALLING	BIT(0)
+#define TQMX86_INT_TRIG_RISING	BIT(1)
+#define TQMX86_INT_TRIG_BOTH	(BIT(0) | BIT(1))
+#define TQMX86_INT_TRIG_MASK	(BIT(0) | BIT(1))
+/* Stored in irq_type with GPII bits */
+#define TQMX86_INT_UNMASKED	BIT(2)
+
+#define TQMX86_GPIIC_CONFIG(i, v)	((v) << (2 * (i)))
+#define TQMX86_GPIIC_MASK(i)		TQMX86_GPIIC_CONFIG(i, TQMX86_INT_TRIG_MASK)
 
 struct tqmx86_gpio_data {
 	struct gpio_chip	chip;
-	struct irq_chip		irq_chip;
 	void __iomem		*io_base;
 	int			irq;
+	/* Lock must be held for accessing output and irq_type fields */
 	raw_spinlock_t		spinlock;
-	u8			irq_type[TQMX86_NGPI];
+	DECLARE_BITMAP(output, TQMX86_NGPIO);
+	u8			irq_type[TQMX86_NGPIO];
 };
 
 static u8 tqmx86_gpio_read(struct tqmx86_gpio_data *gd, unsigned int reg)
@@ -52,6 +66,18 @@ static void tqmx86_gpio_write(struct tqmx86_gpio_data *gd, u8 val,
 	iowrite8(val, gd->io_base + reg);
 }
 
+static void tqmx86_gpio_clrsetbits(struct tqmx86_gpio_data *gpio,
+				   u8 clr, u8 set, unsigned int reg)
+	__must_hold(&gpio->spinlock)
+{
+	u8 val = tqmx86_gpio_read(gpio, reg);
+
+	val &= ~clr;
+	val |= set;
+
+	tqmx86_gpio_write(gpio, val, reg);
+}
+
 static int tqmx86_gpio_get(struct gpio_chip *chip, unsigned int offset)
 {
 	struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
@@ -59,120 +85,139 @@ static int tqmx86_gpio_get(struct gpio_chip *chip, unsigned int offset)
 	return !!(tqmx86_gpio_read(gpio, TQMX86_GPIOD) & BIT(offset));
 }
 
-static void tqmx86_gpio_set(struct gpio_chip *chip, unsigned int offset,
-			    int value)
+static void _tqmx86_gpio_set(struct tqmx86_gpio_data *gpio, unsigned int offset,
+			     int value)
+	__must_hold(&gpio->spinlock)
+{
+	__assign_bit(offset, gpio->output, value);
+	tqmx86_gpio_write(gpio, bitmap_get_value8(gpio->output, 0), TQMX86_GPIOD);
+}
+
+static int tqmx86_gpio_set(struct gpio_chip *chip, unsigned int offset,
+			   int value)
 {
 	struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
-	unsigned long flags;
-	u8 val;
 
-	raw_spin_lock_irqsave(&gpio->spinlock, flags);
-	val = tqmx86_gpio_read(gpio, TQMX86_GPIOD);
-	if (value)
-		val |= BIT(offset);
-	else
-		val &= ~BIT(offset);
-	tqmx86_gpio_write(gpio, val, TQMX86_GPIOD);
-	raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
+	guard(raw_spinlock_irqsave)(&gpio->spinlock);
+
+	_tqmx86_gpio_set(gpio, offset, value);
+
+	return 0;
 }
 
 static int tqmx86_gpio_direction_input(struct gpio_chip *chip,
 				       unsigned int offset)
 {
-	/* Direction cannot be changed. Validate is an input. */
-	if (BIT(offset) & TQMX86_DIR_INPUT_MASK)
-		return 0;
-	else
-		return -EINVAL;
+	struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
+
+	guard(raw_spinlock_irqsave)(&gpio->spinlock);
+
+	tqmx86_gpio_clrsetbits(gpio, BIT(offset), 0, TQMX86_GPIODD);
+
+	return 0;
 }
 
 static int tqmx86_gpio_direction_output(struct gpio_chip *chip,
 					unsigned int offset,
 					int value)
 {
-	/* Direction cannot be changed, validate is an output */
-	if (BIT(offset) & TQMX86_DIR_INPUT_MASK)
-		return -EINVAL;
+	struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
+
+	guard(raw_spinlock_irqsave)(&gpio->spinlock);
+
+	_tqmx86_gpio_set(gpio, offset, value);
+	tqmx86_gpio_clrsetbits(gpio, 0, BIT(offset), TQMX86_GPIODD);
 
-	tqmx86_gpio_set(chip, offset, value);
 	return 0;
 }
 
 static int tqmx86_gpio_get_direction(struct gpio_chip *chip,
 				     unsigned int offset)
 {
-	if (TQMX86_DIR_INPUT_MASK & BIT(offset))
-		return GPIO_LINE_DIRECTION_IN;
+	struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
+	u8 val;
+
+	val = tqmx86_gpio_read(gpio, TQMX86_GPIODD);
+
+	if (val & BIT(offset))
+		return GPIO_LINE_DIRECTION_OUT;
+
+	return GPIO_LINE_DIRECTION_IN;
+}
+
+static void tqmx86_gpio_irq_config(struct tqmx86_gpio_data *gpio, int hwirq)
+	__must_hold(&gpio->spinlock)
+{
+	u8 type = TQMX86_INT_TRIG_NONE;
+	int gpiic_irq = hwirq - TQMX86_NGPO;
+
+	if (gpio->irq_type[hwirq] & TQMX86_INT_UNMASKED) {
+		type = gpio->irq_type[hwirq] & TQMX86_INT_TRIG_MASK;
+
+		if (type == TQMX86_INT_TRIG_BOTH)
+			type = tqmx86_gpio_get(&gpio->chip, hwirq)
+				? TQMX86_INT_TRIG_FALLING
+				: TQMX86_INT_TRIG_RISING;
+	}
 
-	return GPIO_LINE_DIRECTION_OUT;
+	tqmx86_gpio_clrsetbits(gpio,
+			       TQMX86_GPIIC_MASK(gpiic_irq),
+			       TQMX86_GPIIC_CONFIG(gpiic_irq, type),
+			       TQMX86_GPIIC);
 }
 
 static void tqmx86_gpio_irq_mask(struct irq_data *data)
 {
-	unsigned int offset = (data->hwirq - TQMX86_NGPO);
 	struct tqmx86_gpio_data *gpio = gpiochip_get_data(
 		irq_data_get_irq_chip_data(data));
-	unsigned long flags;
-	u8 gpiic, mask;
 
-	mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS);
+	scoped_guard(raw_spinlock_irqsave, &gpio->spinlock) {
+		gpio->irq_type[data->hwirq] &= ~TQMX86_INT_UNMASKED;
+		tqmx86_gpio_irq_config(gpio, data->hwirq);
+	}
 
-	raw_spin_lock_irqsave(&gpio->spinlock, flags);
-	gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
-	gpiic &= ~mask;
-	tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
-	raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
+	gpiochip_disable_irq(&gpio->chip, irqd_to_hwirq(data));
 }
 
 static void tqmx86_gpio_irq_unmask(struct irq_data *data)
 {
-	unsigned int offset = (data->hwirq - TQMX86_NGPO);
 	struct tqmx86_gpio_data *gpio = gpiochip_get_data(
 		irq_data_get_irq_chip_data(data));
-	unsigned long flags;
-	u8 gpiic, mask;
 
-	mask = TQMX86_GPII_MASK << (offset * TQMX86_GPII_BITS);
+	gpiochip_enable_irq(&gpio->chip, irqd_to_hwirq(data));
+
+	guard(raw_spinlock_irqsave)(&gpio->spinlock);
 
-	raw_spin_lock_irqsave(&gpio->spinlock, flags);
-	gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
-	gpiic &= ~mask;
-	gpiic |= gpio->irq_type[offset] << (offset * TQMX86_GPII_BITS);
-	tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
-	raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
+	gpio->irq_type[data->hwirq] |= TQMX86_INT_UNMASKED;
+	tqmx86_gpio_irq_config(gpio, data->hwirq);
 }
 
 static int tqmx86_gpio_irq_set_type(struct irq_data *data, unsigned int type)
 {
 	struct tqmx86_gpio_data *gpio = gpiochip_get_data(
 		irq_data_get_irq_chip_data(data));
-	unsigned int offset = (data->hwirq - TQMX86_NGPO);
 	unsigned int edge_type = type & IRQF_TRIGGER_MASK;
-	unsigned long flags;
-	u8 new_type, gpiic;
+	u8 new_type;
 
 	switch (edge_type) {
 	case IRQ_TYPE_EDGE_RISING:
-		new_type = TQMX86_GPII_RISING;
+		new_type = TQMX86_INT_TRIG_RISING;
 		break;
 	case IRQ_TYPE_EDGE_FALLING:
-		new_type = TQMX86_GPII_FALLING;
+		new_type = TQMX86_INT_TRIG_FALLING;
 		break;
 	case IRQ_TYPE_EDGE_BOTH:
-		new_type = TQMX86_GPII_FALLING | TQMX86_GPII_RISING;
+		new_type = TQMX86_INT_TRIG_BOTH;
 		break;
 	default:
 		return -EINVAL; /* not supported */
 	}
 
-	gpio->irq_type[offset] = new_type;
+	guard(raw_spinlock_irqsave)(&gpio->spinlock);
 
-	raw_spin_lock_irqsave(&gpio->spinlock, flags);
-	gpiic = tqmx86_gpio_read(gpio, TQMX86_GPIIC);
-	gpiic &= ~((TQMX86_GPII_MASK) << (offset * TQMX86_GPII_BITS));
-	gpiic |= new_type << (offset * TQMX86_GPII_BITS);
-	tqmx86_gpio_write(gpio, gpiic, TQMX86_GPIIC);
-	raw_spin_unlock_irqrestore(&gpio->spinlock, flags);
+	gpio->irq_type[data->hwirq] &= ~TQMX86_INT_TRIG_MASK;
+	gpio->irq_type[data->hwirq] |= new_type;
+	tqmx86_gpio_irq_config(gpio, data->hwirq);
 
 	return 0;
 }
@@ -183,7 +228,7 @@ static void tqmx86_gpio_irq_handler(struct irq_desc *desc)
 	struct tqmx86_gpio_data *gpio = gpiochip_get_data(chip);
 	struct irq_chip *irq_chip = irq_desc_get_chip(desc);
 	unsigned long irq_bits;
-	int i = 0, child_irq;
+	int i, hwirq;
 	u8 irq_status;
 
 	chained_irq_enter(irq_chip, desc);
@@ -192,29 +237,60 @@ static void tqmx86_gpio_irq_handler(struct irq_desc *desc)
 	tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS);
 
 	irq_bits = irq_status;
-	for_each_set_bit(i, &irq_bits, TQMX86_NGPI) {
-		child_irq = irq_find_mapping(gpio->chip.irq.domain,
-					     i + TQMX86_NGPO);
-		generic_handle_irq(child_irq);
+
+	scoped_guard(raw_spinlock_irqsave, &gpio->spinlock) {
+		for_each_set_bit(i, &irq_bits, TQMX86_NGPI) {
+			hwirq = i + TQMX86_NGPO;
+
+			/*
+			 * Edge-both triggers are implemented by flipping the
+			 * edge trigger after each interrupt, as the controller
+			 * only supports either rising or falling edge triggers,
+			 * but not both.
+			 *
+			 * Internally, the TQMx86 GPIO controller has separate
+			 * status registers for rising and falling edge
+			 * interrupts. GPIIC configures which bits from which
+			 * register are visible in the interrupt status register
+			 * GPIIS and defines what triggers the parent IRQ line.
+			 * Writing to GPIIS always clears both rising and
+			 * falling interrupt flags internally, regardless of the
+			 * currently configured trigger.
+			 *
+			 * In consequence, we can cleanly implement the
+			 * edge-both trigger in software by first clearing the
+			 * interrupt and then setting the new trigger based on
+			 * the current GPIO input in tqmx86_gpio_irq_config() -
+			 * even if an edge arrives between reading the input and
+			 * setting the trigger, we will have a new interrupt
+			 * pending.
+			 */
+			if ((gpio->irq_type[hwirq] & TQMX86_INT_TRIG_MASK) ==
+			    TQMX86_INT_TRIG_BOTH)
+				tqmx86_gpio_irq_config(gpio, hwirq);
+		}
 	}
 
+	for_each_set_bit(i, &irq_bits, TQMX86_NGPI)
+		generic_handle_domain_irq(gpio->chip.irq.domain,
+					  i + TQMX86_NGPO);
+
 	chained_irq_exit(irq_chip, desc);
 }
 
 /* Minimal runtime PM is needed by the IRQ subsystem */
-static int __maybe_unused tqmx86_gpio_runtime_suspend(struct device *dev)
+static int tqmx86_gpio_runtime_suspend(struct device *dev)
 {
 	return 0;
 }
 
-static int __maybe_unused tqmx86_gpio_runtime_resume(struct device *dev)
+static int tqmx86_gpio_runtime_resume(struct device *dev)
 {
 	return 0;
 }
 
 static const struct dev_pm_ops tqmx86_gpio_dev_pm_ops = {
-	SET_RUNTIME_PM_OPS(tqmx86_gpio_runtime_suspend,
-			   tqmx86_gpio_runtime_resume, NULL)
+	RUNTIME_PM_OPS(tqmx86_gpio_runtime_suspend, tqmx86_gpio_runtime_resume, NULL)
 };
 
 static void tqmx86_init_irq_valid_mask(struct gpio_chip *chip,
@@ -228,6 +304,22 @@ static void tqmx86_init_irq_valid_mask(struct gpio_chip *chip,
 	clear_bit(3, valid_mask);
 }
 
+static void tqmx86_gpio_irq_print_chip(struct irq_data *d, struct seq_file *p)
+{
+	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
+
+	seq_puts(p, gc->label);
+}
+
+static const struct irq_chip tqmx86_gpio_irq_chip = {
+	.irq_mask = tqmx86_gpio_irq_mask,
+	.irq_unmask = tqmx86_gpio_irq_unmask,
+	.irq_set_type = tqmx86_gpio_irq_set_type,
+	.irq_print_chip = tqmx86_gpio_irq_print_chip,
+	.flags = IRQCHIP_IMMUTABLE,
+	GPIOCHIP_IRQ_RESOURCE_HELPERS,
+};
+
 static int tqmx86_gpio_probe(struct platform_device *pdev)
 {
 	struct device *dev = &pdev->dev;
@@ -238,8 +330,8 @@ static int tqmx86_gpio_probe(struct platform_device *pdev)
 	struct resource *res;
 	int ret, irq;
 
-	irq = platform_get_irq(pdev, 0);
-	if (irq < 0)
+	irq = platform_get_irq_optional(pdev, 0);
+	if (irq < 0 && irq != -ENXIO)
 		return irq;
 
 	res = platform_get_resource(pdev, IORESOURCE_IO, 0);
@@ -261,7 +353,12 @@ static int tqmx86_gpio_probe(struct platform_device *pdev)
 
 	tqmx86_gpio_write(gpio, (u8)~TQMX86_DIR_INPUT_MASK, TQMX86_GPIODD);
 
-	platform_set_drvdata(pdev, gpio);
+	/*
+	 * Reading the previous output state is not possible with TQMx86 hardware.
+	 * Initialize all outputs to 0 to have a defined state that matches the
+	 * shadow register.
+	 */
+	tqmx86_gpio_write(gpio, 0, TQMX86_GPIOD);
 
 	chip = &gpio->chip;
 	chip->label = "gpio-tqmx86";
@@ -278,16 +375,9 @@ static int tqmx86_gpio_probe(struct platform_device *pdev)
 
 	pm_runtime_enable(&pdev->dev);
 
-	if (irq) {
-		struct irq_chip *irq_chip = &gpio->irq_chip;
+	if (irq > 0) {
 		u8 irq_status;
 
-		irq_chip->name = chip->label;
-		irq_chip->parent_device = &pdev->dev;
-		irq_chip->irq_mask = tqmx86_gpio_irq_mask;
-		irq_chip->irq_unmask = tqmx86_gpio_irq_unmask;
-		irq_chip->irq_set_type = tqmx86_gpio_irq_set_type;
-
 		/* Mask all interrupts */
 		tqmx86_gpio_write(gpio, 0, TQMX86_GPIIC);
 
@@ -296,7 +386,7 @@ static int tqmx86_gpio_probe(struct platform_device *pdev)
 		tqmx86_gpio_write(gpio, irq_status, TQMX86_GPIIS);
 
 		girq = &chip->irq;
-		girq->chip = irq_chip;
+		gpio_irq_chip_set_chip(girq, &tqmx86_gpio_irq_chip);
 		girq->parent_handler = tqmx86_gpio_irq_handler;
 		girq->num_parents = 1;
 		girq->parents = devm_kcalloc(&pdev->dev, 1,
@@ -310,6 +400,8 @@ static int tqmx86_gpio_probe(struct platform_device *pdev)
 		girq->default_type = IRQ_TYPE_NONE;
 		girq->handler = handle_simple_irq;
 		girq->init_valid_mask = tqmx86_init_irq_valid_mask;
+
+		irq_domain_set_pm_device(girq->domain, dev);
 	}
 
 	ret = devm_gpiochip_add_data(dev, chip, gpio);
@@ -332,7 +424,7 @@ out_pm_dis:
 static struct platform_driver tqmx86_gpio_driver = {
 	.driver = {
 		.name = "tqmx86-gpio",
-		.pm = &tqmx86_gpio_dev_pm_ops,
+		.pm = pm_ptr(&tqmx86_gpio_dev_pm_ops),
 	},
 	.probe		= tqmx86_gpio_probe,
 };