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linux-next/drivers/gpio/gpio-sprd.c
Taiping Lai 5fcface659 gpio: sprd: Clear interrupt when setting the type as edge 
The raw interrupt status of GPIO maybe set before the interrupt is enabled,
which would trigger the interrupt event once enabled it from user side.
This is the case for edge interrupts only. Adding a clear operation when
setting interrupt type can avoid that.

There're a few considerations for the solution:
1) This issue is for edge interrupt only; The interrupts requested by users
   are IRQ_TYPE_LEVEL_HIGH as default, so clearing interrupt when request
   is useless.
2) The interrupt type can be set to edge when request and following up
   with clearing it though, but the problem is still there once users set
   the interrupt type to level trggier.
3) We can add a clear operation after each time of setting interrupt
   enable bit, but it is redundant for level trigger interrupt.

Therefore, the solution is this patch seems the best for now.

Fixes: 9a3821c2bb ("gpio: Add GPIO driver for Spreadtrum SC9860 platform")
Signed-off-by: Taiping Lai <taiping.lai@unisoc.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Reviewed-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
2020-08-31 18:06:28 +02:00

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7.9 KiB
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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2018 Spreadtrum Communications Inc.
* Copyright (C) 2018 Linaro Ltd.
*/
#include <linux/bitops.h>
#include <linux/gpio/driver.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_device.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
/* GPIO registers definition */
#define SPRD_GPIO_DATA 0x0
#define SPRD_GPIO_DMSK 0x4
#define SPRD_GPIO_DIR 0x8
#define SPRD_GPIO_IS 0xc
#define SPRD_GPIO_IBE 0x10
#define SPRD_GPIO_IEV 0x14
#define SPRD_GPIO_IE 0x18
#define SPRD_GPIO_RIS 0x1c
#define SPRD_GPIO_MIS 0x20
#define SPRD_GPIO_IC 0x24
#define SPRD_GPIO_INEN 0x28
/* We have 16 banks GPIOs and each bank contain 16 GPIOs */
#define SPRD_GPIO_BANK_NR 16
#define SPRD_GPIO_NR 256
#define SPRD_GPIO_BANK_SIZE 0x80
#define SPRD_GPIO_BANK_MASK GENMASK(15, 0)
#define SPRD_GPIO_BIT(x) ((x) & (SPRD_GPIO_BANK_NR - 1))
struct sprd_gpio {
struct gpio_chip chip;
void __iomem *base;
spinlock_t lock;
int irq;
};
static inline void __iomem *sprd_gpio_bank_base(struct sprd_gpio *sprd_gpio,
unsigned int bank)
{
return sprd_gpio->base + SPRD_GPIO_BANK_SIZE * bank;
}
static void sprd_gpio_update(struct gpio_chip *chip, unsigned int offset,
u16 reg, int val)
{
struct sprd_gpio *sprd_gpio = gpiochip_get_data(chip);
void __iomem *base = sprd_gpio_bank_base(sprd_gpio,
offset / SPRD_GPIO_BANK_NR);
unsigned long flags;
u32 tmp;
spin_lock_irqsave(&sprd_gpio->lock, flags);
tmp = readl_relaxed(base + reg);
if (val)
tmp |= BIT(SPRD_GPIO_BIT(offset));
else
tmp &= ~BIT(SPRD_GPIO_BIT(offset));
writel_relaxed(tmp, base + reg);
spin_unlock_irqrestore(&sprd_gpio->lock, flags);
}
static int sprd_gpio_read(struct gpio_chip *chip, unsigned int offset, u16 reg)
{
struct sprd_gpio *sprd_gpio = gpiochip_get_data(chip);
void __iomem *base = sprd_gpio_bank_base(sprd_gpio,
offset / SPRD_GPIO_BANK_NR);
return !!(readl_relaxed(base + reg) & BIT(SPRD_GPIO_BIT(offset)));
}
static int sprd_gpio_request(struct gpio_chip *chip, unsigned int offset)
{
sprd_gpio_update(chip, offset, SPRD_GPIO_DMSK, 1);
return 0;
}
static void sprd_gpio_free(struct gpio_chip *chip, unsigned int offset)
{
sprd_gpio_update(chip, offset, SPRD_GPIO_DMSK, 0);
}
static int sprd_gpio_direction_input(struct gpio_chip *chip,
unsigned int offset)
{
sprd_gpio_update(chip, offset, SPRD_GPIO_DIR, 0);
sprd_gpio_update(chip, offset, SPRD_GPIO_INEN, 1);
return 0;
}
static int sprd_gpio_direction_output(struct gpio_chip *chip,
unsigned int offset, int value)
{
sprd_gpio_update(chip, offset, SPRD_GPIO_DIR, 1);
sprd_gpio_update(chip, offset, SPRD_GPIO_INEN, 0);
sprd_gpio_update(chip, offset, SPRD_GPIO_DATA, value);
return 0;
}
static int sprd_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
return sprd_gpio_read(chip, offset, SPRD_GPIO_DATA);
}
static void sprd_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
sprd_gpio_update(chip, offset, SPRD_GPIO_DATA, value);
}
static void sprd_gpio_irq_mask(struct irq_data *data)
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
u32 offset = irqd_to_hwirq(data);
sprd_gpio_update(chip, offset, SPRD_GPIO_IE, 0);
}
static void sprd_gpio_irq_ack(struct irq_data *data)
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
u32 offset = irqd_to_hwirq(data);
sprd_gpio_update(chip, offset, SPRD_GPIO_IC, 1);
}
static void sprd_gpio_irq_unmask(struct irq_data *data)
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
u32 offset = irqd_to_hwirq(data);
sprd_gpio_update(chip, offset, SPRD_GPIO_IE, 1);
}
static int sprd_gpio_irq_set_type(struct irq_data *data,
unsigned int flow_type)
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(data);
u32 offset = irqd_to_hwirq(data);
switch (flow_type) {
case IRQ_TYPE_EDGE_RISING:
sprd_gpio_update(chip, offset, SPRD_GPIO_IS, 0);
sprd_gpio_update(chip, offset, SPRD_GPIO_IBE, 0);
sprd_gpio_update(chip, offset, SPRD_GPIO_IEV, 1);
sprd_gpio_update(chip, offset, SPRD_GPIO_IC, 1);
irq_set_handler_locked(data, handle_edge_irq);
break;
case IRQ_TYPE_EDGE_FALLING:
sprd_gpio_update(chip, offset, SPRD_GPIO_IS, 0);
sprd_gpio_update(chip, offset, SPRD_GPIO_IBE, 0);
sprd_gpio_update(chip, offset, SPRD_GPIO_IEV, 0);
sprd_gpio_update(chip, offset, SPRD_GPIO_IC, 1);
irq_set_handler_locked(data, handle_edge_irq);
break;
case IRQ_TYPE_EDGE_BOTH:
sprd_gpio_update(chip, offset, SPRD_GPIO_IS, 0);
sprd_gpio_update(chip, offset, SPRD_GPIO_IBE, 1);
sprd_gpio_update(chip, offset, SPRD_GPIO_IC, 1);
irq_set_handler_locked(data, handle_edge_irq);
break;
case IRQ_TYPE_LEVEL_HIGH:
sprd_gpio_update(chip, offset, SPRD_GPIO_IS, 1);
sprd_gpio_update(chip, offset, SPRD_GPIO_IBE, 0);
sprd_gpio_update(chip, offset, SPRD_GPIO_IEV, 1);
irq_set_handler_locked(data, handle_level_irq);
break;
case IRQ_TYPE_LEVEL_LOW:
sprd_gpio_update(chip, offset, SPRD_GPIO_IS, 1);
sprd_gpio_update(chip, offset, SPRD_GPIO_IBE, 0);
sprd_gpio_update(chip, offset, SPRD_GPIO_IEV, 0);
irq_set_handler_locked(data, handle_level_irq);
break;
default:
return -EINVAL;
}
return 0;
}
static void sprd_gpio_irq_handler(struct irq_desc *desc)
{
struct gpio_chip *chip = irq_desc_get_handler_data(desc);
struct irq_chip *ic = irq_desc_get_chip(desc);
struct sprd_gpio *sprd_gpio = gpiochip_get_data(chip);
u32 bank, n, girq;
chained_irq_enter(ic, desc);
for (bank = 0; bank * SPRD_GPIO_BANK_NR < chip->ngpio; bank++) {
void __iomem *base = sprd_gpio_bank_base(sprd_gpio, bank);
unsigned long reg = readl_relaxed(base + SPRD_GPIO_MIS) &
SPRD_GPIO_BANK_MASK;
for_each_set_bit(n, &reg, SPRD_GPIO_BANK_NR) {
girq = irq_find_mapping(chip->irq.domain,
bank * SPRD_GPIO_BANK_NR + n);
generic_handle_irq(girq);
}
}
chained_irq_exit(ic, desc);
}
static struct irq_chip sprd_gpio_irqchip = {
.name = "sprd-gpio",
.irq_ack = sprd_gpio_irq_ack,
.irq_mask = sprd_gpio_irq_mask,
.irq_unmask = sprd_gpio_irq_unmask,
.irq_set_type = sprd_gpio_irq_set_type,
.flags = IRQCHIP_SKIP_SET_WAKE,
};
static int sprd_gpio_probe(struct platform_device *pdev)
{
struct gpio_irq_chip *irq;
struct sprd_gpio *sprd_gpio;
int ret;
sprd_gpio = devm_kzalloc(&pdev->dev, sizeof(*sprd_gpio), GFP_KERNEL);
if (!sprd_gpio)
return -ENOMEM;
sprd_gpio->irq = platform_get_irq(pdev, 0);
if (sprd_gpio->irq < 0)
return sprd_gpio->irq;
sprd_gpio->base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(sprd_gpio->base))
return PTR_ERR(sprd_gpio->base);
spin_lock_init(&sprd_gpio->lock);
sprd_gpio->chip.label = dev_name(&pdev->dev);
sprd_gpio->chip.ngpio = SPRD_GPIO_NR;
sprd_gpio->chip.base = -1;
sprd_gpio->chip.parent = &pdev->dev;
sprd_gpio->chip.of_node = pdev->dev.of_node;
sprd_gpio->chip.request = sprd_gpio_request;
sprd_gpio->chip.free = sprd_gpio_free;
sprd_gpio->chip.get = sprd_gpio_get;
sprd_gpio->chip.set = sprd_gpio_set;
sprd_gpio->chip.direction_input = sprd_gpio_direction_input;
sprd_gpio->chip.direction_output = sprd_gpio_direction_output;
irq = &sprd_gpio->chip.irq;
irq->chip = &sprd_gpio_irqchip;
irq->handler = handle_bad_irq;
irq->default_type = IRQ_TYPE_NONE;
irq->parent_handler = sprd_gpio_irq_handler;
irq->parent_handler_data = sprd_gpio;
irq->num_parents = 1;
irq->parents = &sprd_gpio->irq;
ret = devm_gpiochip_add_data(&pdev->dev, &sprd_gpio->chip, sprd_gpio);
if (ret < 0) {
dev_err(&pdev->dev, "Could not register gpiochip %d\n", ret);
return ret;
}
platform_set_drvdata(pdev, sprd_gpio);
return 0;
}
static const struct of_device_id sprd_gpio_of_match[] = {
{ .compatible = "sprd,sc9860-gpio", },
{ /* end of list */ }
};
MODULE_DEVICE_TABLE(of, sprd_gpio_of_match);
static struct platform_driver sprd_gpio_driver = {
.probe = sprd_gpio_probe,
.driver = {
.name = "sprd-gpio",
.of_match_table = sprd_gpio_of_match,
},
};
module_platform_driver_probe(sprd_gpio_driver, sprd_gpio_probe);
MODULE_DESCRIPTION("Spreadtrum GPIO driver");
MODULE_LICENSE("GPL v2");
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