linux/drivers/gpio/gpio-xlp.c
Linus Walleij 2093bcd872 gpio: xlp: Convert to immutable irq_chip
Convert the driver to immutable irq-chip with a bit of
intuition.

In this case the driver uses .mask_ack() and .unmask()
and since I have a vague idea about the semantics of
.mask_ack() I added .irq_enable() to the existing .irq_disable()
and called into the gpiolib core from those callbacks
instead of mask/unmask.

Cc: Marc Zyngier <maz@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
2023-03-23 14:31:19 +01:00

329 lines
8.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2003-2015 Broadcom Corporation
* All Rights Reserved
*/
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>
#include <linux/module.h>
#include <linux/irq.h>
#include <linux/interrupt.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/acpi.h>
/*
* XLP GPIO has multiple 32 bit registers for each feature where each register
* controls 32 pins. So, pins up to 64 require 2 32-bit registers and up to 96
* require 3 32-bit registers for each feature.
* Here we only define offset of the first register for each feature. Offset of
* the registers for pins greater than 32 can be calculated as following(Use
* GPIO_INT_STAT as example):
*
* offset = (gpio / XLP_GPIO_REGSZ) * 4;
* reg_addr = addr + offset;
*
* where addr is base address of the that feature register and gpio is the pin.
*/
#define GPIO_9XX_BYTESWAP 0X00
#define GPIO_9XX_CTRL 0X04
#define GPIO_9XX_OUTPUT_EN 0x14
#define GPIO_9XX_PADDRV 0x24
/*
* Only for 4 interrupt enable reg are defined for now,
* total reg available are 12.
*/
#define GPIO_9XX_INT_EN00 0x44
#define GPIO_9XX_INT_EN10 0x54
#define GPIO_9XX_INT_EN20 0x64
#define GPIO_9XX_INT_EN30 0x74
#define GPIO_9XX_INT_POL 0x104
#define GPIO_9XX_INT_TYPE 0x114
#define GPIO_9XX_INT_STAT 0x124
/* Interrupt type register mask */
#define XLP_GPIO_IRQ_TYPE_LVL 0x0
#define XLP_GPIO_IRQ_TYPE_EDGE 0x1
/* Interrupt polarity register mask */
#define XLP_GPIO_IRQ_POL_HIGH 0x0
#define XLP_GPIO_IRQ_POL_LOW 0x1
#define XLP_GPIO_REGSZ 32
#define XLP_GPIO_IRQ_BASE 768
#define XLP_MAX_NR_GPIO 96
struct xlp_gpio_priv {
struct gpio_chip chip;
DECLARE_BITMAP(gpio_enabled_mask, XLP_MAX_NR_GPIO);
void __iomem *gpio_intr_en; /* pointer to first intr enable reg */
void __iomem *gpio_intr_stat; /* pointer to first intr status reg */
void __iomem *gpio_intr_type; /* pointer to first intr type reg */
void __iomem *gpio_intr_pol; /* pointer to first intr polarity reg */
void __iomem *gpio_out_en; /* pointer to first output enable reg */
void __iomem *gpio_paddrv; /* pointer to first pad drive reg */
spinlock_t lock;
};
static int xlp_gpio_get_reg(void __iomem *addr, unsigned gpio)
{
u32 pos, regset;
pos = gpio % XLP_GPIO_REGSZ;
regset = (gpio / XLP_GPIO_REGSZ) * 4;
return !!(readl(addr + regset) & BIT(pos));
}
static void xlp_gpio_set_reg(void __iomem *addr, unsigned gpio, int state)
{
u32 value, pos, regset;
pos = gpio % XLP_GPIO_REGSZ;
regset = (gpio / XLP_GPIO_REGSZ) * 4;
value = readl(addr + regset);
if (state)
value |= BIT(pos);
else
value &= ~BIT(pos);
writel(value, addr + regset);
}
static void xlp_gpio_irq_enable(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
gpiochip_enable_irq(gc, irqd_to_hwirq(d));
}
static void xlp_gpio_irq_disable(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct xlp_gpio_priv *priv = gpiochip_get_data(gc);
unsigned long flags;
spin_lock_irqsave(&priv->lock, flags);
xlp_gpio_set_reg(priv->gpio_intr_en, d->hwirq, 0x0);
__clear_bit(d->hwirq, priv->gpio_enabled_mask);
spin_unlock_irqrestore(&priv->lock, flags);
gpiochip_disable_irq(gc, irqd_to_hwirq(d));
}
static void xlp_gpio_irq_mask_ack(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct xlp_gpio_priv *priv = gpiochip_get_data(gc);
unsigned long flags;
spin_lock_irqsave(&priv->lock, flags);
xlp_gpio_set_reg(priv->gpio_intr_en, d->hwirq, 0x0);
xlp_gpio_set_reg(priv->gpio_intr_stat, d->hwirq, 0x1);
__clear_bit(d->hwirq, priv->gpio_enabled_mask);
spin_unlock_irqrestore(&priv->lock, flags);
}
static void xlp_gpio_irq_unmask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct xlp_gpio_priv *priv = gpiochip_get_data(gc);
unsigned long flags;
spin_lock_irqsave(&priv->lock, flags);
xlp_gpio_set_reg(priv->gpio_intr_en, d->hwirq, 0x1);
__set_bit(d->hwirq, priv->gpio_enabled_mask);
spin_unlock_irqrestore(&priv->lock, flags);
}
static int xlp_gpio_set_irq_type(struct irq_data *d, unsigned int type)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct xlp_gpio_priv *priv = gpiochip_get_data(gc);
int pol, irq_type;
switch (type) {
case IRQ_TYPE_EDGE_RISING:
irq_type = XLP_GPIO_IRQ_TYPE_EDGE;
pol = XLP_GPIO_IRQ_POL_HIGH;
break;
case IRQ_TYPE_EDGE_FALLING:
irq_type = XLP_GPIO_IRQ_TYPE_EDGE;
pol = XLP_GPIO_IRQ_POL_LOW;
break;
case IRQ_TYPE_LEVEL_HIGH:
irq_type = XLP_GPIO_IRQ_TYPE_LVL;
pol = XLP_GPIO_IRQ_POL_HIGH;
break;
case IRQ_TYPE_LEVEL_LOW:
irq_type = XLP_GPIO_IRQ_TYPE_LVL;
pol = XLP_GPIO_IRQ_POL_LOW;
break;
default:
return -EINVAL;
}
xlp_gpio_set_reg(priv->gpio_intr_type, d->hwirq, irq_type);
xlp_gpio_set_reg(priv->gpio_intr_pol, d->hwirq, pol);
return 0;
}
static struct irq_chip xlp_gpio_irq_chip = {
.name = "XLP-GPIO",
.irq_mask_ack = xlp_gpio_irq_mask_ack,
.irq_enable = xlp_gpio_irq_enable,
.irq_disable = xlp_gpio_irq_disable,
.irq_set_type = xlp_gpio_set_irq_type,
.irq_unmask = xlp_gpio_irq_unmask,
.flags = IRQCHIP_ONESHOT_SAFE | IRQCHIP_IMMUTABLE,
GPIOCHIP_IRQ_RESOURCE_HELPERS,
};
static void xlp_gpio_generic_handler(struct irq_desc *desc)
{
struct xlp_gpio_priv *priv = irq_desc_get_handler_data(desc);
struct irq_chip *irqchip = irq_desc_get_chip(desc);
int gpio, regoff;
u32 gpio_stat;
regoff = -1;
gpio_stat = 0;
chained_irq_enter(irqchip, desc);
for_each_set_bit(gpio, priv->gpio_enabled_mask, XLP_MAX_NR_GPIO) {
if (regoff != gpio / XLP_GPIO_REGSZ) {
regoff = gpio / XLP_GPIO_REGSZ;
gpio_stat = readl(priv->gpio_intr_stat + regoff * 4);
}
if (gpio_stat & BIT(gpio % XLP_GPIO_REGSZ))
generic_handle_domain_irq(priv->chip.irq.domain, gpio);
}
chained_irq_exit(irqchip, desc);
}
static int xlp_gpio_dir_output(struct gpio_chip *gc, unsigned gpio, int state)
{
struct xlp_gpio_priv *priv = gpiochip_get_data(gc);
BUG_ON(gpio >= gc->ngpio);
xlp_gpio_set_reg(priv->gpio_out_en, gpio, 0x1);
return 0;
}
static int xlp_gpio_dir_input(struct gpio_chip *gc, unsigned gpio)
{
struct xlp_gpio_priv *priv = gpiochip_get_data(gc);
BUG_ON(gpio >= gc->ngpio);
xlp_gpio_set_reg(priv->gpio_out_en, gpio, 0x0);
return 0;
}
static int xlp_gpio_get(struct gpio_chip *gc, unsigned gpio)
{
struct xlp_gpio_priv *priv = gpiochip_get_data(gc);
BUG_ON(gpio >= gc->ngpio);
return xlp_gpio_get_reg(priv->gpio_paddrv, gpio);
}
static void xlp_gpio_set(struct gpio_chip *gc, unsigned gpio, int state)
{
struct xlp_gpio_priv *priv = gpiochip_get_data(gc);
BUG_ON(gpio >= gc->ngpio);
xlp_gpio_set_reg(priv->gpio_paddrv, gpio, state);
}
static int xlp_gpio_probe(struct platform_device *pdev)
{
struct gpio_chip *gc;
struct gpio_irq_chip *girq;
struct xlp_gpio_priv *priv;
void __iomem *gpio_base;
int irq, err;
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
gpio_base = devm_platform_ioremap_resource(pdev, 0);
if (IS_ERR(gpio_base))
return PTR_ERR(gpio_base);
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
priv->gpio_out_en = gpio_base + GPIO_9XX_OUTPUT_EN;
priv->gpio_paddrv = gpio_base + GPIO_9XX_PADDRV;
priv->gpio_intr_stat = gpio_base + GPIO_9XX_INT_STAT;
priv->gpio_intr_type = gpio_base + GPIO_9XX_INT_TYPE;
priv->gpio_intr_pol = gpio_base + GPIO_9XX_INT_POL;
priv->gpio_intr_en = gpio_base + GPIO_9XX_INT_EN00;
bitmap_zero(priv->gpio_enabled_mask, XLP_MAX_NR_GPIO);
gc = &priv->chip;
gc->owner = THIS_MODULE;
gc->label = dev_name(&pdev->dev);
gc->base = 0;
gc->parent = &pdev->dev;
gc->ngpio = 70;
gc->direction_output = xlp_gpio_dir_output;
gc->direction_input = xlp_gpio_dir_input;
gc->set = xlp_gpio_set;
gc->get = xlp_gpio_get;
spin_lock_init(&priv->lock);
girq = &gc->irq;
gpio_irq_chip_set_chip(girq, &xlp_gpio_irq_chip);
girq->parent_handler = xlp_gpio_generic_handler;
girq->num_parents = 1;
girq->parents = devm_kcalloc(&pdev->dev, 1,
sizeof(*girq->parents),
GFP_KERNEL);
if (!girq->parents)
return -ENOMEM;
girq->parents[0] = irq;
girq->first = 0;
girq->default_type = IRQ_TYPE_NONE;
girq->handler = handle_level_irq;
err = gpiochip_add_data(gc, priv);
if (err < 0)
return err;
dev_info(&pdev->dev, "registered %d GPIOs\n", gc->ngpio);
return 0;
}
#ifdef CONFIG_ACPI
static const struct acpi_device_id xlp_gpio_acpi_match[] = {
{ "BRCM9006" },
{ "CAV9006" },
{},
};
MODULE_DEVICE_TABLE(acpi, xlp_gpio_acpi_match);
#endif
static struct platform_driver xlp_gpio_driver = {
.driver = {
.name = "xlp-gpio",
.acpi_match_table = ACPI_PTR(xlp_gpio_acpi_match),
},
.probe = xlp_gpio_probe,
};
module_platform_driver(xlp_gpio_driver);
MODULE_AUTHOR("Kamlakant Patel <kamlakant.patel@broadcom.com>");
MODULE_AUTHOR("Ganesan Ramalingam <ganesanr@broadcom.com>");
MODULE_DESCRIPTION("Netlogic XLP GPIO Driver");
MODULE_LICENSE("GPL v2");