linux/drivers/gpio/gpio-merrifield.c
Andy Shevchenko fcce9f14f0 gpio: merrifield: Protect irq_ack() and gpio_set() by lock
There is a potential race when two threads do the writes to the same register
in parallel.

Prevent out of order in such case by protecting I/O access by spin lock.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-07-22 15:30:42 +02:00

445 lines
11 KiB
C

/*
* Intel Merrifield SoC GPIO driver
*
* Copyright (c) 2016 Intel Corporation.
* Author: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
*
* 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/gpio/driver.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/pinctrl/consumer.h>
#define GCCR 0x000 /* controller configuration */
#define GPLR 0x004 /* pin level r/o */
#define GPDR 0x01c /* pin direction */
#define GPSR 0x034 /* pin set w/o */
#define GPCR 0x04c /* pin clear w/o */
#define GRER 0x064 /* rising edge detect */
#define GFER 0x07c /* falling edge detect */
#define GFBR 0x094 /* glitch filter bypass */
#define GIMR 0x0ac /* interrupt mask */
#define GISR 0x0c4 /* interrupt source */
#define GITR 0x300 /* input type */
#define GLPR 0x318 /* level input polarity */
#define GWMR 0x400 /* wake mask */
#define GWSR 0x418 /* wake source */
#define GSIR 0xc00 /* secure input */
/* Intel Merrifield has 192 GPIO pins */
#define MRFLD_NGPIO 192
struct mrfld_gpio_pinrange {
unsigned int gpio_base;
unsigned int pin_base;
unsigned int npins;
};
#define GPIO_PINRANGE(gstart, gend, pstart) \
{ \
.gpio_base = (gstart), \
.pin_base = (pstart), \
.npins = (gend) - (gstart) + 1, \
}
struct mrfld_gpio {
struct gpio_chip chip;
void __iomem *reg_base;
raw_spinlock_t lock;
struct device *dev;
};
static const struct mrfld_gpio_pinrange mrfld_gpio_ranges[] = {
GPIO_PINRANGE(0, 11, 146),
GPIO_PINRANGE(12, 13, 144),
GPIO_PINRANGE(14, 15, 35),
GPIO_PINRANGE(16, 16, 164),
GPIO_PINRANGE(17, 18, 105),
GPIO_PINRANGE(19, 22, 101),
GPIO_PINRANGE(23, 30, 107),
GPIO_PINRANGE(32, 43, 67),
GPIO_PINRANGE(44, 63, 195),
GPIO_PINRANGE(64, 67, 140),
GPIO_PINRANGE(68, 69, 165),
GPIO_PINRANGE(70, 71, 65),
GPIO_PINRANGE(72, 76, 228),
GPIO_PINRANGE(77, 86, 37),
GPIO_PINRANGE(87, 87, 48),
GPIO_PINRANGE(88, 88, 47),
GPIO_PINRANGE(89, 96, 49),
GPIO_PINRANGE(97, 97, 34),
GPIO_PINRANGE(102, 119, 83),
GPIO_PINRANGE(120, 123, 79),
GPIO_PINRANGE(124, 135, 115),
GPIO_PINRANGE(137, 142, 158),
GPIO_PINRANGE(154, 163, 24),
GPIO_PINRANGE(164, 176, 215),
GPIO_PINRANGE(177, 189, 127),
GPIO_PINRANGE(190, 191, 178),
};
static void __iomem *gpio_reg(struct gpio_chip *chip, unsigned int offset,
unsigned int reg_type_offset)
{
struct mrfld_gpio *priv = gpiochip_get_data(chip);
u8 reg = offset / 32;
return priv->reg_base + reg_type_offset + reg * 4;
}
static int mrfld_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
void __iomem *gplr = gpio_reg(chip, offset, GPLR);
return !!(readl(gplr) & BIT(offset % 32));
}
static void mrfld_gpio_set(struct gpio_chip *chip, unsigned int offset,
int value)
{
struct mrfld_gpio *priv = gpiochip_get_data(chip);
void __iomem *gpsr, *gpcr;
unsigned long flags;
raw_spin_lock_irqsave(&priv->lock, flags);
if (value) {
gpsr = gpio_reg(chip, offset, GPSR);
writel(BIT(offset % 32), gpsr);
} else {
gpcr = gpio_reg(chip, offset, GPCR);
writel(BIT(offset % 32), gpcr);
}
raw_spin_unlock_irqrestore(&priv->lock, flags);
}
static int mrfld_gpio_direction_input(struct gpio_chip *chip,
unsigned int offset)
{
struct mrfld_gpio *priv = gpiochip_get_data(chip);
void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
unsigned long flags;
u32 value;
raw_spin_lock_irqsave(&priv->lock, flags);
value = readl(gpdr);
value &= ~BIT(offset % 32);
writel(value, gpdr);
raw_spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
static int mrfld_gpio_direction_output(struct gpio_chip *chip,
unsigned int offset, int value)
{
struct mrfld_gpio *priv = gpiochip_get_data(chip);
void __iomem *gpdr = gpio_reg(chip, offset, GPDR);
unsigned long flags;
mrfld_gpio_set(chip, offset, value);
raw_spin_lock_irqsave(&priv->lock, flags);
value = readl(gpdr);
value |= BIT(offset % 32);
writel(value, gpdr);
raw_spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
static void mrfld_irq_ack(struct irq_data *d)
{
struct mrfld_gpio *priv = irq_data_get_irq_chip_data(d);
u32 gpio = irqd_to_hwirq(d);
void __iomem *gisr = gpio_reg(&priv->chip, gpio, GISR);
unsigned long flags;
raw_spin_lock_irqsave(&priv->lock, flags);
writel(BIT(gpio % 32), gisr);
raw_spin_unlock_irqrestore(&priv->lock, flags);
}
static void mrfld_irq_unmask_mask(struct irq_data *d, bool unmask)
{
struct mrfld_gpio *priv = irq_data_get_irq_chip_data(d);
u32 gpio = irqd_to_hwirq(d);
void __iomem *gimr = gpio_reg(&priv->chip, gpio, GIMR);
unsigned long flags;
u32 value;
raw_spin_lock_irqsave(&priv->lock, flags);
if (unmask)
value = readl(gimr) | BIT(gpio % 32);
else
value = readl(gimr) & ~BIT(gpio % 32);
writel(value, gimr);
raw_spin_unlock_irqrestore(&priv->lock, flags);
}
static void mrfld_irq_mask(struct irq_data *d)
{
mrfld_irq_unmask_mask(d, false);
}
static void mrfld_irq_unmask(struct irq_data *d)
{
mrfld_irq_unmask_mask(d, true);
}
static int mrfld_irq_set_type(struct irq_data *d, unsigned int type)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct mrfld_gpio *priv = gpiochip_get_data(gc);
u32 gpio = irqd_to_hwirq(d);
void __iomem *grer = gpio_reg(&priv->chip, gpio, GRER);
void __iomem *gfer = gpio_reg(&priv->chip, gpio, GFER);
void __iomem *gitr = gpio_reg(&priv->chip, gpio, GITR);
void __iomem *glpr = gpio_reg(&priv->chip, gpio, GLPR);
unsigned long flags;
u32 value;
raw_spin_lock_irqsave(&priv->lock, flags);
if (type & IRQ_TYPE_EDGE_RISING)
value = readl(grer) | BIT(gpio % 32);
else
value = readl(grer) & ~BIT(gpio % 32);
writel(value, grer);
if (type & IRQ_TYPE_EDGE_FALLING)
value = readl(gfer) | BIT(gpio % 32);
else
value = readl(gfer) & ~BIT(gpio % 32);
writel(value, gfer);
/*
* To prevent glitches from triggering an unintended level interrupt,
* configure GLPR register first and then configure GITR.
*/
if (type & IRQ_TYPE_LEVEL_LOW)
value = readl(glpr) | BIT(gpio % 32);
else
value = readl(glpr) & ~BIT(gpio % 32);
writel(value, glpr);
if (type & IRQ_TYPE_LEVEL_MASK) {
value = readl(gitr) | BIT(gpio % 32);
writel(value, gitr);
irq_set_handler_locked(d, handle_level_irq);
} else if (type & IRQ_TYPE_EDGE_BOTH) {
value = readl(gitr) & ~BIT(gpio % 32);
writel(value, gitr);
irq_set_handler_locked(d, handle_edge_irq);
}
raw_spin_unlock_irqrestore(&priv->lock, flags);
return 0;
}
static int mrfld_irq_set_wake(struct irq_data *d, unsigned int on)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct mrfld_gpio *priv = gpiochip_get_data(gc);
u32 gpio = irqd_to_hwirq(d);
void __iomem *gwmr = gpio_reg(&priv->chip, gpio, GWMR);
void __iomem *gwsr = gpio_reg(&priv->chip, gpio, GWSR);
unsigned long flags;
u32 value;
raw_spin_lock_irqsave(&priv->lock, flags);
/* Clear the existing wake status */
writel(BIT(gpio % 32), gwsr);
if (on)
value = readl(gwmr) | BIT(gpio % 32);
else
value = readl(gwmr) & ~BIT(gpio % 32);
writel(value, gwmr);
raw_spin_unlock_irqrestore(&priv->lock, flags);
dev_dbg(priv->dev, "%sable wake for gpio %u\n", on ? "en" : "dis", gpio);
return 0;
}
static struct irq_chip mrfld_irqchip = {
.name = "gpio-merrifield",
.irq_ack = mrfld_irq_ack,
.irq_mask = mrfld_irq_mask,
.irq_unmask = mrfld_irq_unmask,
.irq_set_type = mrfld_irq_set_type,
.irq_set_wake = mrfld_irq_set_wake,
};
static void mrfld_irq_handler(struct irq_desc *desc)
{
struct gpio_chip *gc = irq_desc_get_handler_data(desc);
struct mrfld_gpio *priv = gpiochip_get_data(gc);
struct irq_chip *irqchip = irq_desc_get_chip(desc);
unsigned long base, gpio;
chained_irq_enter(irqchip, desc);
/* Check GPIO controller to check which pin triggered the interrupt */
for (base = 0; base < priv->chip.ngpio; base += 32) {
void __iomem *gisr = gpio_reg(&priv->chip, base, GISR);
void __iomem *gimr = gpio_reg(&priv->chip, base, GIMR);
unsigned long pending, enabled;
pending = readl(gisr);
enabled = readl(gimr);
/* Only interrupts that are enabled */
pending &= enabled;
for_each_set_bit(gpio, &pending, 32) {
unsigned int irq;
irq = irq_find_mapping(gc->irqdomain, base + gpio);
generic_handle_irq(irq);
}
}
chained_irq_exit(irqchip, desc);
}
static void mrfld_irq_init_hw(struct mrfld_gpio *priv)
{
void __iomem *reg;
unsigned int base;
for (base = 0; base < priv->chip.ngpio; base += 32) {
/* Clear the rising-edge detect register */
reg = gpio_reg(&priv->chip, base, GRER);
writel(0, reg);
/* Clear the falling-edge detect register */
reg = gpio_reg(&priv->chip, base, GFER);
writel(0, reg);
}
}
static int mrfld_gpio_probe(struct pci_dev *pdev, const struct pci_device_id *id)
{
const struct mrfld_gpio_pinrange *range;
struct mrfld_gpio *priv;
u32 gpio_base, irq_base;
void __iomem *base;
unsigned int i;
int retval;
retval = pcim_enable_device(pdev);
if (retval)
return retval;
retval = pcim_iomap_regions(pdev, BIT(1) | BIT(0), pci_name(pdev));
if (retval) {
dev_err(&pdev->dev, "I/O memory mapping error\n");
return retval;
}
base = pcim_iomap_table(pdev)[1];
irq_base = readl(base);
gpio_base = readl(sizeof(u32) + base);
/* Release the IO mapping, since we already get the info from BAR1 */
pcim_iounmap_regions(pdev, BIT(1));
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv) {
dev_err(&pdev->dev, "can't allocate chip data\n");
return -ENOMEM;
}
priv->dev = &pdev->dev;
priv->reg_base = pcim_iomap_table(pdev)[0];
priv->chip.label = dev_name(&pdev->dev);
priv->chip.parent = &pdev->dev;
priv->chip.request = gpiochip_generic_request;
priv->chip.free = gpiochip_generic_free;
priv->chip.direction_input = mrfld_gpio_direction_input;
priv->chip.direction_output = mrfld_gpio_direction_output;
priv->chip.get = mrfld_gpio_get;
priv->chip.set = mrfld_gpio_set;
priv->chip.base = gpio_base;
priv->chip.ngpio = MRFLD_NGPIO;
priv->chip.can_sleep = false;
raw_spin_lock_init(&priv->lock);
pci_set_drvdata(pdev, priv);
retval = devm_gpiochip_add_data(&pdev->dev, &priv->chip, priv);
if (retval) {
dev_err(&pdev->dev, "gpiochip_add error %d\n", retval);
return retval;
}
for (i = 0; i < ARRAY_SIZE(mrfld_gpio_ranges); i++) {
range = &mrfld_gpio_ranges[i];
retval = gpiochip_add_pin_range(&priv->chip,
"pinctrl-merrifield",
range->gpio_base,
range->pin_base,
range->npins);
if (retval) {
dev_err(&pdev->dev, "failed to add GPIO pin range\n");
return retval;
}
}
retval = gpiochip_irqchip_add(&priv->chip, &mrfld_irqchip, irq_base,
handle_simple_irq, IRQ_TYPE_NONE);
if (retval) {
dev_err(&pdev->dev, "could not connect irqchip to gpiochip\n");
return retval;
}
mrfld_irq_init_hw(priv);
gpiochip_set_chained_irqchip(&priv->chip, &mrfld_irqchip, pdev->irq,
mrfld_irq_handler);
return 0;
}
static const struct pci_device_id mrfld_gpio_ids[] = {
{ PCI_VDEVICE(INTEL, 0x1199) },
{ }
};
MODULE_DEVICE_TABLE(pci, mrfld_gpio_ids);
static struct pci_driver mrfld_gpio_driver = {
.name = "gpio-merrifield",
.id_table = mrfld_gpio_ids,
.probe = mrfld_gpio_probe,
};
module_pci_driver(mrfld_gpio_driver);
MODULE_AUTHOR("Andy Shevchenko <andriy.shevchenko@linux.intel.com>");
MODULE_DESCRIPTION("Intel Merrifield SoC GPIO driver");
MODULE_LICENSE("GPL v2");