linux/drivers/gpio/gpio-cadence.c
Uwe Kleine-König 67c811b601 gpio: cadence: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is ignored (apart
from emitting a warning) and this typically results in resource leaks.

To improve here there is a quest to make the remove callback return
void. In the first step of this quest all drivers are converted to
.remove_new(), which already returns void. Eventually after all drivers
are converted, .remove_new() will be renamed to .remove().

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2023-10-02 08:54:26 +02:00

299 lines
7.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2017-2018 Cadence
*
* Authors:
* Jan Kotas <jank@cadence.com>
* Boris Brezillon <boris.brezillon@free-electrons.com>
*/
#include <linux/gpio/driver.h>
#include <linux/clk.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#define CDNS_GPIO_BYPASS_MODE 0x00
#define CDNS_GPIO_DIRECTION_MODE 0x04
#define CDNS_GPIO_OUTPUT_EN 0x08
#define CDNS_GPIO_OUTPUT_VALUE 0x0c
#define CDNS_GPIO_INPUT_VALUE 0x10
#define CDNS_GPIO_IRQ_MASK 0x14
#define CDNS_GPIO_IRQ_EN 0x18
#define CDNS_GPIO_IRQ_DIS 0x1c
#define CDNS_GPIO_IRQ_STATUS 0x20
#define CDNS_GPIO_IRQ_TYPE 0x24
#define CDNS_GPIO_IRQ_VALUE 0x28
#define CDNS_GPIO_IRQ_ANY_EDGE 0x2c
struct cdns_gpio_chip {
struct gpio_chip gc;
struct clk *pclk;
void __iomem *regs;
u32 bypass_orig;
};
static int cdns_gpio_request(struct gpio_chip *chip, unsigned int offset)
{
struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
unsigned long flags;
raw_spin_lock_irqsave(&chip->bgpio_lock, flags);
iowrite32(ioread32(cgpio->regs + CDNS_GPIO_BYPASS_MODE) & ~BIT(offset),
cgpio->regs + CDNS_GPIO_BYPASS_MODE);
raw_spin_unlock_irqrestore(&chip->bgpio_lock, flags);
return 0;
}
static void cdns_gpio_free(struct gpio_chip *chip, unsigned int offset)
{
struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
unsigned long flags;
raw_spin_lock_irqsave(&chip->bgpio_lock, flags);
iowrite32(ioread32(cgpio->regs + CDNS_GPIO_BYPASS_MODE) |
(BIT(offset) & cgpio->bypass_orig),
cgpio->regs + CDNS_GPIO_BYPASS_MODE);
raw_spin_unlock_irqrestore(&chip->bgpio_lock, flags);
}
static void cdns_gpio_irq_mask(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
iowrite32(BIT(d->hwirq), cgpio->regs + CDNS_GPIO_IRQ_DIS);
gpiochip_disable_irq(chip, irqd_to_hwirq(d));
}
static void cdns_gpio_irq_unmask(struct irq_data *d)
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
gpiochip_enable_irq(chip, irqd_to_hwirq(d));
iowrite32(BIT(d->hwirq), cgpio->regs + CDNS_GPIO_IRQ_EN);
}
static int cdns_gpio_irq_set_type(struct irq_data *d, unsigned int type)
{
struct gpio_chip *chip = irq_data_get_irq_chip_data(d);
struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
unsigned long flags;
u32 int_value;
u32 int_type;
u32 mask = BIT(d->hwirq);
int ret = 0;
raw_spin_lock_irqsave(&chip->bgpio_lock, flags);
int_value = ioread32(cgpio->regs + CDNS_GPIO_IRQ_VALUE) & ~mask;
int_type = ioread32(cgpio->regs + CDNS_GPIO_IRQ_TYPE) & ~mask;
/*
* The GPIO controller doesn't have an ACK register.
* All interrupt statuses are cleared on a status register read.
* Don't support edge interrupts for now.
*/
if (type == IRQ_TYPE_LEVEL_HIGH) {
int_type |= mask;
int_value |= mask;
} else if (type == IRQ_TYPE_LEVEL_LOW) {
int_type |= mask;
} else {
ret = -EINVAL;
goto err_irq_type;
}
iowrite32(int_value, cgpio->regs + CDNS_GPIO_IRQ_VALUE);
iowrite32(int_type, cgpio->regs + CDNS_GPIO_IRQ_TYPE);
err_irq_type:
raw_spin_unlock_irqrestore(&chip->bgpio_lock, flags);
return ret;
}
static void cdns_gpio_irq_handler(struct irq_desc *desc)
{
struct gpio_chip *chip = irq_desc_get_handler_data(desc);
struct cdns_gpio_chip *cgpio = gpiochip_get_data(chip);
struct irq_chip *irqchip = irq_desc_get_chip(desc);
unsigned long status;
int hwirq;
chained_irq_enter(irqchip, desc);
status = ioread32(cgpio->regs + CDNS_GPIO_IRQ_STATUS) &
~ioread32(cgpio->regs + CDNS_GPIO_IRQ_MASK);
for_each_set_bit(hwirq, &status, chip->ngpio)
generic_handle_domain_irq(chip->irq.domain, hwirq);
chained_irq_exit(irqchip, desc);
}
static const struct irq_chip cdns_gpio_irqchip = {
.name = "cdns-gpio",
.irq_mask = cdns_gpio_irq_mask,
.irq_unmask = cdns_gpio_irq_unmask,
.irq_set_type = cdns_gpio_irq_set_type,
.flags = IRQCHIP_IMMUTABLE,
GPIOCHIP_IRQ_RESOURCE_HELPERS,
};
static int cdns_gpio_probe(struct platform_device *pdev)
{
struct cdns_gpio_chip *cgpio;
int ret, irq;
u32 dir_prev;
u32 num_gpios = 32;
cgpio = devm_kzalloc(&pdev->dev, sizeof(*cgpio), GFP_KERNEL);
if (!cgpio)
return -ENOMEM;
cgpio->regs = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(cgpio->regs))
return PTR_ERR(cgpio->regs);
of_property_read_u32(pdev->dev.of_node, "ngpios", &num_gpios);
if (num_gpios > 32) {
dev_err(&pdev->dev, "ngpios must be less or equal 32\n");
return -EINVAL;
}
/*
* Set all pins as inputs by default, otherwise:
* gpiochip_lock_as_irq:
* tried to flag a GPIO set as output for IRQ
* Generic GPIO driver stores the direction value internally,
* so it needs to be changed before bgpio_init() is called.
*/
dir_prev = ioread32(cgpio->regs + CDNS_GPIO_DIRECTION_MODE);
iowrite32(GENMASK(num_gpios - 1, 0),
cgpio->regs + CDNS_GPIO_DIRECTION_MODE);
ret = bgpio_init(&cgpio->gc, &pdev->dev, 4,
cgpio->regs + CDNS_GPIO_INPUT_VALUE,
cgpio->regs + CDNS_GPIO_OUTPUT_VALUE,
NULL,
NULL,
cgpio->regs + CDNS_GPIO_DIRECTION_MODE,
BGPIOF_READ_OUTPUT_REG_SET);
if (ret) {
dev_err(&pdev->dev, "Failed to register generic gpio, %d\n",
ret);
goto err_revert_dir;
}
cgpio->gc.label = dev_name(&pdev->dev);
cgpio->gc.ngpio = num_gpios;
cgpio->gc.parent = &pdev->dev;
cgpio->gc.base = -1;
cgpio->gc.owner = THIS_MODULE;
cgpio->gc.request = cdns_gpio_request;
cgpio->gc.free = cdns_gpio_free;
cgpio->pclk = devm_clk_get(&pdev->dev, NULL);
if (IS_ERR(cgpio->pclk)) {
ret = PTR_ERR(cgpio->pclk);
dev_err(&pdev->dev,
"Failed to retrieve peripheral clock, %d\n", ret);
goto err_revert_dir;
}
ret = clk_prepare_enable(cgpio->pclk);
if (ret) {
dev_err(&pdev->dev,
"Failed to enable the peripheral clock, %d\n", ret);
goto err_revert_dir;
}
/*
* Optional irq_chip support
*/
irq = platform_get_irq(pdev, 0);
if (irq >= 0) {
struct gpio_irq_chip *girq;
girq = &cgpio->gc.irq;
gpio_irq_chip_set_chip(girq, &cdns_gpio_irqchip);
girq->parent_handler = cdns_gpio_irq_handler;
girq->num_parents = 1;
girq->parents = devm_kcalloc(&pdev->dev, 1,
sizeof(*girq->parents),
GFP_KERNEL);
if (!girq->parents) {
ret = -ENOMEM;
goto err_disable_clk;
}
girq->parents[0] = irq;
girq->default_type = IRQ_TYPE_NONE;
girq->handler = handle_level_irq;
}
ret = devm_gpiochip_add_data(&pdev->dev, &cgpio->gc, cgpio);
if (ret < 0) {
dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
goto err_disable_clk;
}
cgpio->bypass_orig = ioread32(cgpio->regs + CDNS_GPIO_BYPASS_MODE);
/*
* Enable gpio outputs, ignored for input direction
*/
iowrite32(GENMASK(num_gpios - 1, 0),
cgpio->regs + CDNS_GPIO_OUTPUT_EN);
iowrite32(0, cgpio->regs + CDNS_GPIO_BYPASS_MODE);
platform_set_drvdata(pdev, cgpio);
return 0;
err_disable_clk:
clk_disable_unprepare(cgpio->pclk);
err_revert_dir:
iowrite32(dir_prev, cgpio->regs + CDNS_GPIO_DIRECTION_MODE);
return ret;
}
static void cdns_gpio_remove(struct platform_device *pdev)
{
struct cdns_gpio_chip *cgpio = platform_get_drvdata(pdev);
iowrite32(cgpio->bypass_orig, cgpio->regs + CDNS_GPIO_BYPASS_MODE);
clk_disable_unprepare(cgpio->pclk);
}
static const struct of_device_id cdns_of_ids[] = {
{ .compatible = "cdns,gpio-r1p02" },
{ /* sentinel */ },
};
MODULE_DEVICE_TABLE(of, cdns_of_ids);
static struct platform_driver cdns_gpio_driver = {
.driver = {
.name = "cdns-gpio",
.of_match_table = cdns_of_ids,
},
.probe = cdns_gpio_probe,
.remove_new = cdns_gpio_remove,
};
module_platform_driver(cdns_gpio_driver);
MODULE_AUTHOR("Jan Kotas <jank@cadence.com>");
MODULE_DESCRIPTION("Cadence GPIO driver");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:cdns-gpio");