[PATCH v4 1/2] gpio: mlxbf2: Introduce IRQ support

Asmaa Mnebhi
2021-10-08T14:50:10Z

Introduce standard IRQ handling in the gpio-mlxbf2.c
driver.

Signed-off-by: Asmaa Mnebhi <asmaa@nvidia.com>
---
drivers/gpio/gpio-mlxbf2.c | 147 ++++++++++++++++++++++++++++++++++++-
1 file changed, 145 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-mlxbf2.c b/drivers/gpio/gpio-mlxbf2.c
index 177d03ef4529..3d89912a05b8 100644
--- a/drivers/gpio/gpio-mlxbf2.c
+++ b/drivers/gpio/gpio-mlxbf2.c
@@ -1,9 +1,14 @@
// SPDX-License-Identifier: GPL-2.0

+/*
+ * Copyright (C) 2020-2021 NVIDIA CORPORATION & AFFILIATES
+ */
+
#include <linux/bitfield.h>
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/gpio/driver.h>
+#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/ioport.h>
#include <linux/kernel.h>
@@ -43,9 +48,14 @@
#define YU_GPIO_MODE0 0x0c
#define YU_GPIO_DATASET 0x14
#define YU_GPIO_DATACLEAR 0x18
+#define YU_GPIO_CAUSE_RISE_EN 0x44
+#define YU_GPIO_CAUSE_FALL_EN 0x48
#define YU_GPIO_MODE1_CLEAR 0x50
#define YU_GPIO_MODE0_SET 0x54
#define YU_GPIO_MODE0_CLEAR 0x58
+#define YU_GPIO_CAUSE_OR_CAUSE_EVTEN0 0x80
+#define YU_GPIO_CAUSE_OR_EVTEN0 0x94
+#define YU_GPIO_CAUSE_OR_CLRCAUSE 0x98

struct mlxbf2_gpio_context_save_regs {
u32 gpio_mode0;
@@ -55,6 +65,7 @@ struct mlxbf2_gpio_context_save_regs {
/* BlueField-2 gpio block context structure. */
struct mlxbf2_gpio_context {
struct gpio_chip gc;
+ struct irq_chip irq_chip;

/* YU GPIO blocks address */
void __iomem *gpio_io;
@@ -218,15 +229,114 @@ static int mlxbf2_gpio_direction_output(struct gpio_chip *chip,
return ret;
}

+static void mlxbf2_gpio_irq_enable(struct irq_data *irqd)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+ struct mlxbf2_gpio_context *gs = gpiochip_get_data(gc);
+ int offset = irqd_to_hwirq(irqd);
+ unsigned long flags;
+ u32 val;
+
+ spin_lock_irqsave(&gs->gc.bgpio_lock, flags);
+ val = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_CLRCAUSE);
+ val |= BIT(offset);
+ writel(val, gs->gpio_io + YU_GPIO_CAUSE_OR_CLRCAUSE);
+
+ val = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0);
+ val |= BIT(offset);
+ writel(val, gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0);
+ spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);
+}
+
+static void mlxbf2_gpio_irq_disable(struct irq_data *irqd)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+ struct mlxbf2_gpio_context *gs = gpiochip_get_data(gc);
+ int offset = irqd_to_hwirq(irqd);
+ unsigned long flags;
+ u32 val;
+
+ spin_lock_irqsave(&gs->gc.bgpio_lock, flags);
+ val = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0);
+ val &= ~BIT(offset);
+ writel(val, gs->gpio_io + YU_GPIO_CAUSE_OR_EVTEN0);
+ spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);
+}
+
+static irqreturn_t mlxbf2_gpio_irq_handler(int irq, void *ptr)
+{
+ struct mlxbf2_gpio_context *gs = ptr;
+ struct gpio_chip *gc = &gs->gc;
+ unsigned long pending;
+ u32 level;
+
+ pending = readl(gs->gpio_io + YU_GPIO_CAUSE_OR_CAUSE_EVTEN0);
+ writel(pending, gs->gpio_io + YU_GPIO_CAUSE_OR_CLRCAUSE);
+
+ for_each_set_bit(level, &pending, gc->ngpio) {
+ int gpio_irq = irq_find_mapping(gc->irq.domain, level);
+ generic_handle_irq(gpio_irq);
+ }
+
+ return IRQ_RETVAL(pending);
+}
+
+static int
+mlxbf2_gpio_irq_set_type(struct irq_data *irqd, unsigned int type)
+{
+ struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
+ struct mlxbf2_gpio_context *gs = gpiochip_get_data(gc);
+ int offset = irqd_to_hwirq(irqd);
+ unsigned long flags;
+ bool fall = false;
+ bool rise = false;
+ u32 val;
+
+ switch (type & IRQ_TYPE_SENSE_MASK) {
+ case IRQ_TYPE_EDGE_BOTH:
+ fall = true;
+ rise = true;
+ break;
+ case IRQ_TYPE_EDGE_RISING:
+ rise = true;
+ break;
+ case IRQ_TYPE_EDGE_FALLING:
+ fall = true;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ spin_lock_irqsave(&gs->gc.bgpio_lock, flags);
+ if (fall) {
+ val = readl(gs->gpio_io + YU_GPIO_CAUSE_FALL_EN);
+ val |= BIT(offset);
+ writel(val, gs->gpio_io + YU_GPIO_CAUSE_FALL_EN);
+ }
+
+ if (rise) {
+ val = readl(gs->gpio_io + YU_GPIO_CAUSE_RISE_EN);
+ val |= BIT(offset);
+ writel(val, gs->gpio_io + YU_GPIO_CAUSE_RISE_EN);
+ }
+ spin_unlock_irqrestore(&gs->gc.bgpio_lock, flags);
+
+ return 0;
+}
+
/* BlueField-2 GPIO driver initialization routine. */
static int
mlxbf2_gpio_probe(struct platform_device *pdev)
{
struct mlxbf2_gpio_context *gs;
struct device *dev = &pdev->dev;
+ struct gpio_irq_chip *girq;
struct gpio_chip *gc;
unsigned int npins;
- int ret;
+ const char *name;
+ int ret, irq;
+
+ name = dev_name(dev);

gs = devm_kzalloc(dev, sizeof(*gs), GFP_KERNEL);
if (!gs)
@@ -256,11 +366,44 @@ mlxbf2_gpio_probe(struct platform_device *pdev)
NULL,
0);

+ if (ret) {
+ dev_err(dev, "bgpio_init failed\n");
+ return ret;
+ }
+
gc->direction_input = mlxbf2_gpio_direction_input;
gc->direction_output = mlxbf2_gpio_direction_output;
gc->ngpio = npins;
gc->owner = THIS_MODULE;

+ irq = platform_get_irq(pdev, 0);
+ if (irq >= 0) {
+ gs->irq_chip.name = name;
+ gs->irq_chip.irq_set_type = mlxbf2_gpio_irq_set_type;
+ gs->irq_chip.irq_enable = mlxbf2_gpio_irq_enable;
+ gs->irq_chip.irq_disable = mlxbf2_gpio_irq_disable;
+
+ girq = &gs->gc.irq;
+ girq->chip = &gs->irq_chip;
+ girq->handler = handle_simple_irq;
+ girq->default_type = IRQ_TYPE_NONE;
+ /* This will let us handle the parent IRQ in the driver */
+ girq->num_parents = 0;
+ girq->parents = NULL;
+ girq->parent_handler = NULL;
+
+ /*
+ * Directly request the irq here instead of passing
+ * a flow-handler because the irq is shared.
+ */
+ ret = devm_request_irq(dev, irq, mlxbf2_gpio_irq_handler,
+ IRQF_SHARED, name, gs);
+ if (ret) {
+ dev_err(dev, "failed to request IRQ");
+ return ret;
+ }
+ }
+
platform_set_drvdata(pdev, gs);

ret = devm_gpiochip_add_data(dev, &gs->gc, gs);
@@ -315,5 +458,5 @@ static struct platform_driver mlxbf2_gpio_driver = {
module_platform_driver(mlxbf2_gpio_driver);

MODULE_DESCRIPTION("Mellanox BlueField-2 GPIO Driver");
-MODULE_AUTHOR("Mellanox Technologies");
+MODULE_AUTHOR("Asmaa Mnebhi <asmaa@nvidia.com>");
MODULE_LICENSE("GPL v2");
--
2.30.1