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linux/drivers/gpio/gpio-zx.c
Paul Gortmaker 18fb0a981e gpio: zx: make explicitly non-modular 
The Kconfig currently controlling compilation of this code is:

config GPIO_ZX
        bool "ZTE ZX GPIO support"

...meaning that it currently is not being built as a module by anyone.

Lets remove the couple traces of modularity so that when reading the
driver there is no doubt it is builtin-only.

Since module_platform_driver() uses the same init level priority as
builtin_platform_driver() the init ordering remains unchanged with
this commit.

Also note that MODULE_DEVICE_TABLE is a no-op for non-modular code.

We also delete the MODULE_LICENSE tag etc. since all that information
was (or is now) contained at the top of the file in the comments.

Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Jun Nie <jun.nie@linaro.org>
Cc: linux-gpio@vger.kernel.org
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-03-31 15:10:25 +02:00

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7.4 KiB
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/*
* ZTE ZX296702 GPIO driver
*
* Author: Jun Nie <jun.nie@linaro.org>
*
* Copyright (C) 2015 Linaro Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/gpio/driver.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/init.h>
#include <linux/of.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/pm.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#define ZX_GPIO_DIR 0x00
#define ZX_GPIO_IVE 0x04
#define ZX_GPIO_IV 0x08
#define ZX_GPIO_IEP 0x0C
#define ZX_GPIO_IEN 0x10
#define ZX_GPIO_DI 0x14
#define ZX_GPIO_DO1 0x18
#define ZX_GPIO_DO0 0x1C
#define ZX_GPIO_DO 0x20
#define ZX_GPIO_IM 0x28
#define ZX_GPIO_IE 0x2C
#define ZX_GPIO_MIS 0x30
#define ZX_GPIO_IC 0x34
#define ZX_GPIO_NR 16
struct zx_gpio {
spinlock_t lock;
void __iomem *base;
struct gpio_chip gc;
};
static int zx_direction_input(struct gpio_chip *gc, unsigned offset)
{
struct zx_gpio *chip = gpiochip_get_data(gc);
unsigned long flags;
u16 gpiodir;
if (offset >= gc->ngpio)
return -EINVAL;
spin_lock_irqsave(&chip->lock, flags);
gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR);
gpiodir &= ~BIT(offset);
writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR);
spin_unlock_irqrestore(&chip->lock, flags);
return 0;
}
static int zx_direction_output(struct gpio_chip *gc, unsigned offset,
int value)
{
struct zx_gpio *chip = gpiochip_get_data(gc);
unsigned long flags;
u16 gpiodir;
if (offset >= gc->ngpio)
return -EINVAL;
spin_lock_irqsave(&chip->lock, flags);
gpiodir = readw_relaxed(chip->base + ZX_GPIO_DIR);
gpiodir |= BIT(offset);
writew_relaxed(gpiodir, chip->base + ZX_GPIO_DIR);
if (value)
writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO1);
else
writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO0);
spin_unlock_irqrestore(&chip->lock, flags);
return 0;
}
static int zx_get_value(struct gpio_chip *gc, unsigned offset)
{
struct zx_gpio *chip = gpiochip_get_data(gc);
return !!(readw_relaxed(chip->base + ZX_GPIO_DI) & BIT(offset));
}
static void zx_set_value(struct gpio_chip *gc, unsigned offset, int value)
{
struct zx_gpio *chip = gpiochip_get_data(gc);
if (value)
writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO1);
else
writew_relaxed(BIT(offset), chip->base + ZX_GPIO_DO0);
}
static int zx_irq_type(struct irq_data *d, unsigned trigger)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct zx_gpio *chip = gpiochip_get_data(gc);
int offset = irqd_to_hwirq(d);
unsigned long flags;
u16 gpiois, gpioi_epos, gpioi_eneg, gpioiev;
u16 bit = BIT(offset);
if (offset < 0 || offset >= ZX_GPIO_NR)
return -EINVAL;
spin_lock_irqsave(&chip->lock, flags);
gpioiev = readw_relaxed(chip->base + ZX_GPIO_IV);
gpiois = readw_relaxed(chip->base + ZX_GPIO_IVE);
gpioi_epos = readw_relaxed(chip->base + ZX_GPIO_IEP);
gpioi_eneg = readw_relaxed(chip->base + ZX_GPIO_IEN);
if (trigger & (IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW)) {
gpiois |= bit;
if (trigger & IRQ_TYPE_LEVEL_HIGH)
gpioiev |= bit;
else
gpioiev &= ~bit;
} else
gpiois &= ~bit;
if ((trigger & IRQ_TYPE_EDGE_BOTH) == IRQ_TYPE_EDGE_BOTH) {
gpioi_epos |= bit;
gpioi_eneg |= bit;
} else {
if (trigger & IRQ_TYPE_EDGE_RISING) {
gpioi_epos |= bit;
gpioi_eneg &= ~bit;
} else if (trigger & IRQ_TYPE_EDGE_FALLING) {
gpioi_eneg |= bit;
gpioi_epos &= ~bit;
}
}
writew_relaxed(gpiois, chip->base + ZX_GPIO_IVE);
writew_relaxed(gpioi_epos, chip->base + ZX_GPIO_IEP);
writew_relaxed(gpioi_eneg, chip->base + ZX_GPIO_IEN);
writew_relaxed(gpioiev, chip->base + ZX_GPIO_IV);
spin_unlock_irqrestore(&chip->lock, flags);
return 0;
}
static void zx_irq_handler(struct irq_desc *desc)
{
unsigned long pending;
int offset;
struct gpio_chip *gc = irq_desc_get_handler_data(desc);
struct zx_gpio *chip = gpiochip_get_data(gc);
struct irq_chip *irqchip = irq_desc_get_chip(desc);
chained_irq_enter(irqchip, desc);
pending = readw_relaxed(chip->base + ZX_GPIO_MIS);
writew_relaxed(pending, chip->base + ZX_GPIO_IC);
if (pending) {
for_each_set_bit(offset, &pending, ZX_GPIO_NR)
generic_handle_irq(irq_find_mapping(gc->irqdomain,
offset));
}
chained_irq_exit(irqchip, desc);
}
static void zx_irq_mask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct zx_gpio *chip = gpiochip_get_data(gc);
u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR);
u16 gpioie;
spin_lock(&chip->lock);
gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) | mask;
writew_relaxed(gpioie, chip->base + ZX_GPIO_IM);
gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) & ~mask;
writew_relaxed(gpioie, chip->base + ZX_GPIO_IE);
spin_unlock(&chip->lock);
}
static void zx_irq_unmask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct zx_gpio *chip = gpiochip_get_data(gc);
u16 mask = BIT(irqd_to_hwirq(d) % ZX_GPIO_NR);
u16 gpioie;
spin_lock(&chip->lock);
gpioie = readw_relaxed(chip->base + ZX_GPIO_IM) & ~mask;
writew_relaxed(gpioie, chip->base + ZX_GPIO_IM);
gpioie = readw_relaxed(chip->base + ZX_GPIO_IE) | mask;
writew_relaxed(gpioie, chip->base + ZX_GPIO_IE);
spin_unlock(&chip->lock);
}
static struct irq_chip zx_irqchip = {
.name = "zx-gpio",
.irq_mask = zx_irq_mask,
.irq_unmask = zx_irq_unmask,
.irq_set_type = zx_irq_type,
};
static int zx_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct zx_gpio *chip;
struct resource *res;
int irq, id, ret;
chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
if (!chip)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
chip->base = devm_ioremap_resource(dev, res);
if (IS_ERR(chip->base))
return PTR_ERR(chip->base);
spin_lock_init(&chip->lock);
if (of_property_read_bool(dev->of_node, "gpio-ranges")) {
chip->gc.request = gpiochip_generic_request;
chip->gc.free = gpiochip_generic_free;
}
id = of_alias_get_id(dev->of_node, "gpio");
chip->gc.direction_input = zx_direction_input;
chip->gc.direction_output = zx_direction_output;
chip->gc.get = zx_get_value;
chip->gc.set = zx_set_value;
chip->gc.base = ZX_GPIO_NR * id;
chip->gc.ngpio = ZX_GPIO_NR;
chip->gc.label = dev_name(dev);
chip->gc.parent = dev;
chip->gc.owner = THIS_MODULE;
ret = gpiochip_add_data(&chip->gc, chip);
if (ret)
return ret;
/*
* irq_chip support
*/
writew_relaxed(0xffff, chip->base + ZX_GPIO_IM);
writew_relaxed(0, chip->base + ZX_GPIO_IE);
irq = platform_get_irq(pdev, 0);
if (irq < 0) {
dev_err(dev, "invalid IRQ\n");
gpiochip_remove(&chip->gc);
return -ENODEV;
}
ret = gpiochip_irqchip_add(&chip->gc, &zx_irqchip,
0, handle_simple_irq,
IRQ_TYPE_NONE);
if (ret) {
dev_err(dev, "could not add irqchip\n");
gpiochip_remove(&chip->gc);
return ret;
}
gpiochip_set_chained_irqchip(&chip->gc, &zx_irqchip,
irq, zx_irq_handler);
platform_set_drvdata(pdev, chip);
dev_info(dev, "ZX GPIO chip registered\n");
return 0;
}
static const struct of_device_id zx_gpio_match[] = {
{
.compatible = "zte,zx296702-gpio",
},
{ },
};
static struct platform_driver zx_gpio_driver = {
.probe = zx_gpio_probe,
.driver = {
.name = "zx_gpio",
.of_match_table = of_match_ptr(zx_gpio_match),
},
};
builtin_platform_driver(zx_gpio_driver)
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