linux/drivers/gpio/gpio-bcm-kona.c

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/*
* Copyright (C) 2012-2014 Broadcom Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/bitops.h>
#include <linux/err.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/module.h>
#include <linux/irqdomain.h>
#include <linux/irqchip/chained_irq.h>
#define BCM_GPIO_PASSWD 0x00a5a501
#define GPIO_PER_BANK 32
#define GPIO_MAX_BANK_NUM 8
#define GPIO_BANK(gpio) ((gpio) >> 5)
#define GPIO_BIT(gpio) ((gpio) & (GPIO_PER_BANK - 1))
/* There is a GPIO control register for each GPIO */
#define GPIO_CONTROL(gpio) (0x00000100 + ((gpio) << 2))
/* The remaining registers are per GPIO bank */
#define GPIO_OUT_STATUS(bank) (0x00000000 + ((bank) << 2))
#define GPIO_IN_STATUS(bank) (0x00000020 + ((bank) << 2))
#define GPIO_OUT_SET(bank) (0x00000040 + ((bank) << 2))
#define GPIO_OUT_CLEAR(bank) (0x00000060 + ((bank) << 2))
#define GPIO_INT_STATUS(bank) (0x00000080 + ((bank) << 2))
#define GPIO_INT_MASK(bank) (0x000000a0 + ((bank) << 2))
#define GPIO_INT_MSKCLR(bank) (0x000000c0 + ((bank) << 2))
#define GPIO_PWD_STATUS(bank) (0x00000500 + ((bank) << 2))
#define GPIO_GPPWR_OFFSET 0x00000520
#define GPIO_GPCTR0_DBR_SHIFT 5
#define GPIO_GPCTR0_DBR_MASK 0x000001e0
#define GPIO_GPCTR0_ITR_SHIFT 3
#define GPIO_GPCTR0_ITR_MASK 0x00000018
#define GPIO_GPCTR0_ITR_CMD_RISING_EDGE 0x00000001
#define GPIO_GPCTR0_ITR_CMD_FALLING_EDGE 0x00000002
#define GPIO_GPCTR0_ITR_CMD_BOTH_EDGE 0x00000003
#define GPIO_GPCTR0_IOTR_MASK 0x00000001
#define GPIO_GPCTR0_IOTR_CMD_0UTPUT 0x00000000
#define GPIO_GPCTR0_IOTR_CMD_INPUT 0x00000001
#define GPIO_GPCTR0_DB_ENABLE_MASK 0x00000100
#define LOCK_CODE 0xffffffff
#define UNLOCK_CODE 0x00000000
struct bcm_kona_gpio {
void __iomem *reg_base;
int num_bank;
spinlock_t lock;
struct gpio_chip gpio_chip;
struct irq_domain *irq_domain;
struct bcm_kona_gpio_bank *banks;
struct platform_device *pdev;
};
struct bcm_kona_gpio_bank {
int id;
int irq;
/* Used in the interrupt handler */
struct bcm_kona_gpio *kona_gpio;
};
static inline struct bcm_kona_gpio *to_kona_gpio(struct gpio_chip *chip)
{
return container_of(chip, struct bcm_kona_gpio, gpio_chip);
}
static inline void bcm_kona_gpio_write_lock_regs(void __iomem *reg_base,
int bank_id, u32 lockcode)
{
writel(BCM_GPIO_PASSWD, reg_base + GPIO_GPPWR_OFFSET);
writel(lockcode, reg_base + GPIO_PWD_STATUS(bank_id));
}
static void bcm_kona_gpio_lock_gpio(struct bcm_kona_gpio *kona_gpio,
unsigned gpio)
{
u32 val;
unsigned long flags;
int bank_id = GPIO_BANK(gpio);
spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
val |= BIT(gpio);
bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);
spin_unlock_irqrestore(&kona_gpio->lock, flags);
}
static void bcm_kona_gpio_unlock_gpio(struct bcm_kona_gpio *kona_gpio,
unsigned gpio)
{
u32 val;
unsigned long flags;
int bank_id = GPIO_BANK(gpio);
spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(kona_gpio->reg_base + GPIO_PWD_STATUS(bank_id));
val &= ~BIT(gpio);
bcm_kona_gpio_write_lock_regs(kona_gpio->reg_base, bank_id, val);
spin_unlock_irqrestore(&kona_gpio->lock, flags);
}
static void bcm_kona_gpio_set(struct gpio_chip *chip, unsigned gpio, int value)
{
struct bcm_kona_gpio *kona_gpio;
void __iomem *reg_base;
int bank_id = GPIO_BANK(gpio);
int bit = GPIO_BIT(gpio);
u32 val, reg_offset;
unsigned long flags;
kona_gpio = to_kona_gpio(chip);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
/* determine the GPIO pin direction */
val = readl(reg_base + GPIO_CONTROL(gpio));
val &= GPIO_GPCTR0_IOTR_MASK;
/* this function only applies to output pin */
if (GPIO_GPCTR0_IOTR_CMD_INPUT == val)
goto out;
reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id);
val = readl(reg_base + reg_offset);
val |= BIT(bit);
writel(val, reg_base + reg_offset);
out:
spin_unlock_irqrestore(&kona_gpio->lock, flags);
}
static int bcm_kona_gpio_get(struct gpio_chip *chip, unsigned gpio)
{
struct bcm_kona_gpio *kona_gpio;
void __iomem *reg_base;
int bank_id = GPIO_BANK(gpio);
int bit = GPIO_BIT(gpio);
u32 val, reg_offset;
unsigned long flags;
kona_gpio = to_kona_gpio(chip);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
/* determine the GPIO pin direction */
val = readl(reg_base + GPIO_CONTROL(gpio));
val &= GPIO_GPCTR0_IOTR_MASK;
/* read the GPIO bank status */
reg_offset = (GPIO_GPCTR0_IOTR_CMD_INPUT == val) ?
GPIO_IN_STATUS(bank_id) : GPIO_OUT_STATUS(bank_id);
val = readl(reg_base + reg_offset);
spin_unlock_irqrestore(&kona_gpio->lock, flags);
/* return the specified bit status */
return !!(val & BIT(bit));
}
static int bcm_kona_gpio_request(struct gpio_chip *chip, unsigned gpio)
{
struct bcm_kona_gpio *kona_gpio = to_kona_gpio(chip);
bcm_kona_gpio_unlock_gpio(kona_gpio, gpio);
return 0;
}
static void bcm_kona_gpio_free(struct gpio_chip *chip, unsigned gpio)
{
struct bcm_kona_gpio *kona_gpio = to_kona_gpio(chip);
bcm_kona_gpio_lock_gpio(kona_gpio, gpio);
}
static int bcm_kona_gpio_direction_input(struct gpio_chip *chip, unsigned gpio)
{
struct bcm_kona_gpio *kona_gpio;
void __iomem *reg_base;
u32 val;
unsigned long flags;
kona_gpio = to_kona_gpio(chip);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_CONTROL(gpio));
val &= ~GPIO_GPCTR0_IOTR_MASK;
val |= GPIO_GPCTR0_IOTR_CMD_INPUT;
writel(val, reg_base + GPIO_CONTROL(gpio));
spin_unlock_irqrestore(&kona_gpio->lock, flags);
return 0;
}
static int bcm_kona_gpio_direction_output(struct gpio_chip *chip,
unsigned gpio, int value)
{
struct bcm_kona_gpio *kona_gpio;
void __iomem *reg_base;
int bank_id = GPIO_BANK(gpio);
int bit = GPIO_BIT(gpio);
u32 val, reg_offset;
unsigned long flags;
kona_gpio = to_kona_gpio(chip);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_CONTROL(gpio));
val &= ~GPIO_GPCTR0_IOTR_MASK;
val |= GPIO_GPCTR0_IOTR_CMD_0UTPUT;
writel(val, reg_base + GPIO_CONTROL(gpio));
reg_offset = value ? GPIO_OUT_SET(bank_id) : GPIO_OUT_CLEAR(bank_id);
val = readl(reg_base + reg_offset);
val |= BIT(bit);
writel(val, reg_base + reg_offset);
spin_unlock_irqrestore(&kona_gpio->lock, flags);
return 0;
}
static int bcm_kona_gpio_to_irq(struct gpio_chip *chip, unsigned gpio)
{
struct bcm_kona_gpio *kona_gpio;
kona_gpio = to_kona_gpio(chip);
if (gpio >= kona_gpio->gpio_chip.ngpio)
return -ENXIO;
return irq_create_mapping(kona_gpio->irq_domain, gpio);
}
static int bcm_kona_gpio_set_debounce(struct gpio_chip *chip, unsigned gpio,
unsigned debounce)
{
struct bcm_kona_gpio *kona_gpio;
void __iomem *reg_base;
u32 val, res;
unsigned long flags;
kona_gpio = to_kona_gpio(chip);
reg_base = kona_gpio->reg_base;
/* debounce must be 1-128ms (or 0) */
if ((debounce > 0 && debounce < 1000) || debounce > 128000) {
dev_err(chip->dev, "Debounce value %u not in range\n",
debounce);
return -EINVAL;
}
/* calculate debounce bit value */
if (debounce != 0) {
/* Convert to ms */
debounce /= 1000;
/* find the MSB */
res = fls(debounce) - 1;
/* Check if MSB-1 is set (round up or down) */
if (res > 0 && (debounce & BIT(res - 1)))
res++;
}
/* spin lock for read-modify-write of the GPIO register */
spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_CONTROL(gpio));
val &= ~GPIO_GPCTR0_DBR_MASK;
if (debounce == 0) {
/* disable debounce */
val &= ~GPIO_GPCTR0_DB_ENABLE_MASK;
} else {
val |= GPIO_GPCTR0_DB_ENABLE_MASK |
(res << GPIO_GPCTR0_DBR_SHIFT);
}
writel(val, reg_base + GPIO_CONTROL(gpio));
spin_unlock_irqrestore(&kona_gpio->lock, flags);
return 0;
}
static struct gpio_chip template_chip = {
.label = "bcm-kona-gpio",
.owner = THIS_MODULE,
.request = bcm_kona_gpio_request,
.free = bcm_kona_gpio_free,
.direction_input = bcm_kona_gpio_direction_input,
.get = bcm_kona_gpio_get,
.direction_output = bcm_kona_gpio_direction_output,
.set = bcm_kona_gpio_set,
.set_debounce = bcm_kona_gpio_set_debounce,
.to_irq = bcm_kona_gpio_to_irq,
.base = 0,
};
static void bcm_kona_gpio_irq_ack(struct irq_data *d)
{
struct bcm_kona_gpio *kona_gpio;
void __iomem *reg_base;
unsigned gpio = d->hwirq;
int bank_id = GPIO_BANK(gpio);
int bit = GPIO_BIT(gpio);
u32 val;
unsigned long flags;
kona_gpio = irq_data_get_irq_chip_data(d);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_INT_STATUS(bank_id));
val |= BIT(bit);
writel(val, reg_base + GPIO_INT_STATUS(bank_id));
spin_unlock_irqrestore(&kona_gpio->lock, flags);
}
static void bcm_kona_gpio_irq_mask(struct irq_data *d)
{
struct bcm_kona_gpio *kona_gpio;
void __iomem *reg_base;
unsigned gpio = d->hwirq;
int bank_id = GPIO_BANK(gpio);
int bit = GPIO_BIT(gpio);
u32 val;
unsigned long flags;
kona_gpio = irq_data_get_irq_chip_data(d);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_INT_MASK(bank_id));
val |= BIT(bit);
writel(val, reg_base + GPIO_INT_MASK(bank_id));
spin_unlock_irqrestore(&kona_gpio->lock, flags);
}
static void bcm_kona_gpio_irq_unmask(struct irq_data *d)
{
struct bcm_kona_gpio *kona_gpio;
void __iomem *reg_base;
unsigned gpio = d->hwirq;
int bank_id = GPIO_BANK(gpio);
int bit = GPIO_BIT(gpio);
u32 val;
unsigned long flags;
kona_gpio = irq_data_get_irq_chip_data(d);
reg_base = kona_gpio->reg_base;
spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_INT_MSKCLR(bank_id));
val |= BIT(bit);
writel(val, reg_base + GPIO_INT_MSKCLR(bank_id));
spin_unlock_irqrestore(&kona_gpio->lock, flags);
}
static int bcm_kona_gpio_irq_set_type(struct irq_data *d, unsigned int type)
{
struct bcm_kona_gpio *kona_gpio;
void __iomem *reg_base;
unsigned gpio = d->hwirq;
u32 lvl_type;
u32 val;
unsigned long flags;
kona_gpio = irq_data_get_irq_chip_data(d);
reg_base = kona_gpio->reg_base;
switch (type & IRQ_TYPE_SENSE_MASK) {
case IRQ_TYPE_EDGE_RISING:
lvl_type = GPIO_GPCTR0_ITR_CMD_RISING_EDGE;
break;
case IRQ_TYPE_EDGE_FALLING:
lvl_type = GPIO_GPCTR0_ITR_CMD_FALLING_EDGE;
break;
case IRQ_TYPE_EDGE_BOTH:
lvl_type = GPIO_GPCTR0_ITR_CMD_BOTH_EDGE;
break;
case IRQ_TYPE_LEVEL_HIGH:
case IRQ_TYPE_LEVEL_LOW:
/* BCM GPIO doesn't support level triggering */
default:
dev_err(kona_gpio->gpio_chip.dev,
"Invalid BCM GPIO irq type 0x%x\n", type);
return -EINVAL;
}
spin_lock_irqsave(&kona_gpio->lock, flags);
val = readl(reg_base + GPIO_CONTROL(gpio));
val &= ~GPIO_GPCTR0_ITR_MASK;
val |= lvl_type << GPIO_GPCTR0_ITR_SHIFT;
writel(val, reg_base + GPIO_CONTROL(gpio));
spin_unlock_irqrestore(&kona_gpio->lock, flags);
return 0;
}
static void bcm_kona_gpio_irq_handler(unsigned int irq, struct irq_desc *desc)
{
void __iomem *reg_base;
int bit, bank_id;
unsigned long sta;
struct bcm_kona_gpio_bank *bank = irq_get_handler_data(irq);
struct irq_chip *chip = irq_desc_get_chip(desc);
chained_irq_enter(chip, desc);
/*
* For bank interrupts, we can't use chip_data to store the kona_gpio
* pointer, since GIC needs it for its own purposes. Therefore, we get
* our pointer from the bank structure.
*/
reg_base = bank->kona_gpio->reg_base;
bank_id = bank->id;
while ((sta = readl(reg_base + GPIO_INT_STATUS(bank_id)) &
(~(readl(reg_base + GPIO_INT_MASK(bank_id)))))) {
for_each_set_bit(bit, &sta, 32) {
int hwirq = GPIO_PER_BANK * bank_id + bit;
int child_irq =
irq_find_mapping(bank->kona_gpio->irq_domain,
hwirq);
/*
* Clear interrupt before handler is called so we don't
* miss any interrupt occurred during executing them.
*/
writel(readl(reg_base + GPIO_INT_STATUS(bank_id)) |
BIT(bit), reg_base + GPIO_INT_STATUS(bank_id));
/* Invoke interrupt handler */
generic_handle_irq(child_irq);
}
}
chained_irq_exit(chip, desc);
}
static int bcm_kona_gpio_irq_reqres(struct irq_data *d)
{
struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);
if (gpio_lock_as_irq(&kona_gpio->gpio_chip, d->hwirq)) {
dev_err(kona_gpio->gpio_chip.dev,
"unable to lock HW IRQ %lu for IRQ\n",
d->hwirq);
return -EINVAL;
}
return 0;
}
static void bcm_kona_gpio_irq_relres(struct irq_data *d)
{
struct bcm_kona_gpio *kona_gpio = irq_data_get_irq_chip_data(d);
gpio_unlock_as_irq(&kona_gpio->gpio_chip, d->hwirq);
}
static struct irq_chip bcm_gpio_irq_chip = {
.name = "bcm-kona-gpio",
.irq_ack = bcm_kona_gpio_irq_ack,
.irq_mask = bcm_kona_gpio_irq_mask,
.irq_unmask = bcm_kona_gpio_irq_unmask,
.irq_set_type = bcm_kona_gpio_irq_set_type,
.irq_request_resources = bcm_kona_gpio_irq_reqres,
.irq_release_resources = bcm_kona_gpio_irq_relres,
};
static struct __initconst of_device_id bcm_kona_gpio_of_match[] = {
{ .compatible = "brcm,kona-gpio" },
{}
};
MODULE_DEVICE_TABLE(of, bcm_kona_gpio_of_match);
/*
* This lock class tells lockdep that GPIO irqs are in a different
* category than their parents, so it won't report false recursion.
*/
static struct lock_class_key gpio_lock_class;
static int bcm_kona_gpio_irq_map(struct irq_domain *d, unsigned int irq,
irq_hw_number_t hwirq)
{
int ret;
ret = irq_set_chip_data(irq, d->host_data);
if (ret < 0)
return ret;
irq_set_lockdep_class(irq, &gpio_lock_class);
irq_set_chip_and_handler(irq, &bcm_gpio_irq_chip, handle_simple_irq);
#ifdef CONFIG_ARM
set_irq_flags(irq, IRQF_VALID);
#else
irq_set_noprobe(irq);
#endif
return 0;
}
static void bcm_kona_gpio_irq_unmap(struct irq_domain *d, unsigned int irq)
{
irq_set_chip_and_handler(irq, NULL, NULL);
irq_set_chip_data(irq, NULL);
}
static struct irq_domain_ops bcm_kona_irq_ops = {
.map = bcm_kona_gpio_irq_map,
.unmap = bcm_kona_gpio_irq_unmap,
.xlate = irq_domain_xlate_twocell,
};
static void bcm_kona_gpio_reset(struct bcm_kona_gpio *kona_gpio)
{
void __iomem *reg_base;
int i;
reg_base = kona_gpio->reg_base;
/* disable interrupts and clear status */
for (i = 0; i < kona_gpio->num_bank; i++) {
/* Unlock the entire bank first */
bcm_kona_gpio_write_lock_regs(kona_gpio, i, UNLOCK_CODE);
writel(0xffffffff, reg_base + GPIO_INT_MASK(i));
writel(0xffffffff, reg_base + GPIO_INT_STATUS(i));
/* Now re-lock the bank */
bcm_kona_gpio_write_lock_regs(kona_gpio, i, LOCK_CODE);
}
}
static int bcm_kona_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
const struct of_device_id *match;
struct resource *res;
struct bcm_kona_gpio_bank *bank;
struct bcm_kona_gpio *kona_gpio;
struct gpio_chip *chip;
int ret;
int i;
match = of_match_device(bcm_kona_gpio_of_match, dev);
if (!match) {
dev_err(dev, "Failed to find gpio controller\n");
return -ENODEV;
}
kona_gpio = devm_kzalloc(dev, sizeof(*kona_gpio), GFP_KERNEL);
if (!kona_gpio)
return -ENOMEM;
kona_gpio->gpio_chip = template_chip;
chip = &kona_gpio->gpio_chip;
kona_gpio->num_bank = of_irq_count(dev->of_node);
if (kona_gpio->num_bank == 0) {
dev_err(dev, "Couldn't determine # GPIO banks\n");
return -ENOENT;
}
if (kona_gpio->num_bank > GPIO_MAX_BANK_NUM) {
dev_err(dev, "Too many GPIO banks configured (max=%d)\n",
GPIO_MAX_BANK_NUM);
return -ENXIO;
}
kona_gpio->banks = devm_kzalloc(dev,
kona_gpio->num_bank *
sizeof(*kona_gpio->banks), GFP_KERNEL);
if (!kona_gpio->banks)
return -ENOMEM;
kona_gpio->pdev = pdev;
platform_set_drvdata(pdev, kona_gpio);
chip->of_node = dev->of_node;
chip->ngpio = kona_gpio->num_bank * GPIO_PER_BANK;
kona_gpio->irq_domain = irq_domain_add_linear(dev->of_node,
chip->ngpio,
&bcm_kona_irq_ops,
kona_gpio);
if (!kona_gpio->irq_domain) {
dev_err(dev, "Couldn't allocate IRQ domain\n");
return -ENXIO;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
kona_gpio->reg_base = devm_ioremap_resource(dev, res);
if (IS_ERR(kona_gpio->reg_base)) {
ret = -ENXIO;
goto err_irq_domain;
}
for (i = 0; i < kona_gpio->num_bank; i++) {
bank = &kona_gpio->banks[i];
bank->id = i;
bank->irq = platform_get_irq(pdev, i);
bank->kona_gpio = kona_gpio;
if (bank->irq < 0) {
dev_err(dev, "Couldn't get IRQ for bank %d", i);
ret = -ENOENT;
goto err_irq_domain;
}
}
dev_info(&pdev->dev, "Setting up Kona GPIO\n");
bcm_kona_gpio_reset(kona_gpio);
ret = gpiochip_add(chip);
if (ret < 0) {
dev_err(dev, "Couldn't add GPIO chip -- %d\n", ret);
goto err_irq_domain;
}
for (i = 0; i < chip->ngpio; i++) {
int irq = bcm_kona_gpio_to_irq(chip, i);
irq_set_lockdep_class(irq, &gpio_lock_class);
irq_set_chip_and_handler(irq, &bcm_gpio_irq_chip,
handle_simple_irq);
#ifdef CONFIG_ARM
set_irq_flags(irq, IRQF_VALID);
#else
irq_set_noprobe(irq);
#endif
}
for (i = 0; i < kona_gpio->num_bank; i++) {
bank = &kona_gpio->banks[i];
irq_set_chained_handler(bank->irq, bcm_kona_gpio_irq_handler);
irq_set_handler_data(bank->irq, bank);
}
spin_lock_init(&kona_gpio->lock);
return 0;
err_irq_domain:
irq_domain_remove(kona_gpio->irq_domain);
return ret;
}
static struct platform_driver bcm_kona_gpio_driver = {
.driver = {
.name = "bcm-kona-gpio",
.owner = THIS_MODULE,
.of_match_table = bcm_kona_gpio_of_match,
},
.probe = bcm_kona_gpio_probe,
};
module_platform_driver(bcm_kona_gpio_driver);
MODULE_AUTHOR("Broadcom Corporation <bcm-kernel-feedback-list@broadcom.com>");
MODULE_DESCRIPTION("Broadcom Kona GPIO Driver");
MODULE_LICENSE("GPL v2");