gpio-brcmstb.c
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/*
* Copyright (C) 2015 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/gpio/driver.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/module.h>
#include <linux/basic_mmio_gpio.h>
#include <linux/irqdomain.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/interrupt.h>
#include <linux/reboot.h>
#define GIO_BANK_SIZE 0x20
#define GIO_ODEN(bank) (((bank) * GIO_BANK_SIZE) + 0x00)
#define GIO_DATA(bank) (((bank) * GIO_BANK_SIZE) + 0x04)
#define GIO_IODIR(bank) (((bank) * GIO_BANK_SIZE) + 0x08)
#define GIO_EC(bank) (((bank) * GIO_BANK_SIZE) + 0x0c)
#define GIO_EI(bank) (((bank) * GIO_BANK_SIZE) + 0x10)
#define GIO_MASK(bank) (((bank) * GIO_BANK_SIZE) + 0x14)
#define GIO_LEVEL(bank) (((bank) * GIO_BANK_SIZE) + 0x18)
#define GIO_STAT(bank) (((bank) * GIO_BANK_SIZE) + 0x1c)
struct brcmstb_gpio_bank {
struct list_head node;
int id;
struct bgpio_chip bgc;
struct brcmstb_gpio_priv *parent_priv;
u32 width;
struct irq_chip irq_chip;
};
struct brcmstb_gpio_priv {
struct list_head bank_list;
void __iomem *reg_base;
struct platform_device *pdev;
int parent_irq;
int gpio_base;
bool can_wake;
int parent_wake_irq;
struct notifier_block reboot_notifier;
};
#define MAX_GPIO_PER_BANK 32
#define GPIO_BANK(gpio) ((gpio) >> 5)
/* assumes MAX_GPIO_PER_BANK is a multiple of 2 */
#define GPIO_BIT(gpio) ((gpio) & (MAX_GPIO_PER_BANK - 1))
static inline struct brcmstb_gpio_bank *
brcmstb_gpio_gc_to_bank(struct gpio_chip *gc)
{
struct bgpio_chip *bgc = to_bgpio_chip(gc);
return container_of(bgc, struct brcmstb_gpio_bank, bgc);
}
static inline struct brcmstb_gpio_priv *
brcmstb_gpio_gc_to_priv(struct gpio_chip *gc)
{
struct brcmstb_gpio_bank *bank = brcmstb_gpio_gc_to_bank(gc);
return bank->parent_priv;
}
static void brcmstb_gpio_set_imask(struct brcmstb_gpio_bank *bank,
unsigned int offset, bool enable)
{
struct bgpio_chip *bgc = &bank->bgc;
struct brcmstb_gpio_priv *priv = bank->parent_priv;
u32 mask = bgc->pin2mask(bgc, offset);
u32 imask;
unsigned long flags;
spin_lock_irqsave(&bgc->lock, flags);
imask = bgc->read_reg(priv->reg_base + GIO_MASK(bank->id));
if (enable)
imask |= mask;
else
imask &= ~mask;
bgc->write_reg(priv->reg_base + GIO_MASK(bank->id), imask);
spin_unlock_irqrestore(&bgc->lock, flags);
}
/* -------------------- IRQ chip functions -------------------- */
static void brcmstb_gpio_irq_mask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct brcmstb_gpio_bank *bank = brcmstb_gpio_gc_to_bank(gc);
brcmstb_gpio_set_imask(bank, d->hwirq, false);
}
static void brcmstb_gpio_irq_unmask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct brcmstb_gpio_bank *bank = brcmstb_gpio_gc_to_bank(gc);
brcmstb_gpio_set_imask(bank, d->hwirq, true);
}
static int brcmstb_gpio_irq_set_type(struct irq_data *d, unsigned int type)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct brcmstb_gpio_bank *bank = brcmstb_gpio_gc_to_bank(gc);
struct brcmstb_gpio_priv *priv = bank->parent_priv;
u32 mask = BIT(d->hwirq);
u32 edge_insensitive, iedge_insensitive;
u32 edge_config, iedge_config;
u32 level, ilevel;
unsigned long flags;
switch (type) {
case IRQ_TYPE_LEVEL_LOW:
level = 0;
edge_config = 0;
edge_insensitive = 0;
break;
case IRQ_TYPE_LEVEL_HIGH:
level = mask;
edge_config = 0;
edge_insensitive = 0;
break;
case IRQ_TYPE_EDGE_FALLING:
level = 0;
edge_config = 0;
edge_insensitive = 0;
break;
case IRQ_TYPE_EDGE_RISING:
level = 0;
edge_config = mask;
edge_insensitive = 0;
break;
case IRQ_TYPE_EDGE_BOTH:
level = 0;
edge_config = 0; /* don't care, but want known value */
edge_insensitive = mask;
break;
default:
return -EINVAL;
}
spin_lock_irqsave(&bank->bgc.lock, flags);
iedge_config = bank->bgc.read_reg(priv->reg_base +
GIO_EC(bank->id)) & ~mask;
iedge_insensitive = bank->bgc.read_reg(priv->reg_base +
GIO_EI(bank->id)) & ~mask;
ilevel = bank->bgc.read_reg(priv->reg_base +
GIO_LEVEL(bank->id)) & ~mask;
bank->bgc.write_reg(priv->reg_base + GIO_EC(bank->id),
iedge_config | edge_config);
bank->bgc.write_reg(priv->reg_base + GIO_EI(bank->id),
iedge_insensitive | edge_insensitive);
bank->bgc.write_reg(priv->reg_base + GIO_LEVEL(bank->id),
ilevel | level);
spin_unlock_irqrestore(&bank->bgc.lock, flags);
return 0;
}
static int brcmstb_gpio_priv_set_wake(struct brcmstb_gpio_priv *priv,
unsigned int enable)
{
int ret = 0;
/*
* Only enable wake IRQ once for however many hwirqs can wake
* since they all use the same wake IRQ. Mask will be set
* up appropriately thanks to IRQCHIP_MASK_ON_SUSPEND flag.
*/
if (enable)
ret = enable_irq_wake(priv->parent_wake_irq);
else
ret = disable_irq_wake(priv->parent_wake_irq);
if (ret)
dev_err(&priv->pdev->dev, "failed to %s wake-up interrupt\n",
enable ? "enable" : "disable");
return ret;
}
static int brcmstb_gpio_irq_set_wake(struct irq_data *d, unsigned int enable)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct brcmstb_gpio_priv *priv = brcmstb_gpio_gc_to_priv(gc);
return brcmstb_gpio_priv_set_wake(priv, enable);
}
static irqreturn_t brcmstb_gpio_wake_irq_handler(int irq, void *data)
{
struct brcmstb_gpio_priv *priv = data;
if (!priv || irq != priv->parent_wake_irq)
return IRQ_NONE;
pm_wakeup_event(&priv->pdev->dev, 0);
return IRQ_HANDLED;
}
static void brcmstb_gpio_irq_bank_handler(struct brcmstb_gpio_bank *bank)
{
struct brcmstb_gpio_priv *priv = bank->parent_priv;
struct irq_domain *irq_domain = bank->bgc.gc.irqdomain;
void __iomem *reg_base = priv->reg_base;
unsigned long status;
unsigned long flags;
spin_lock_irqsave(&bank->bgc.lock, flags);
while ((status = bank->bgc.read_reg(reg_base + GIO_STAT(bank->id)) &
bank->bgc.read_reg(reg_base + GIO_MASK(bank->id)))) {
int bit;
for_each_set_bit(bit, &status, 32) {
u32 stat = bank->bgc.read_reg(reg_base +
GIO_STAT(bank->id));
if (bit >= bank->width)
dev_warn(&priv->pdev->dev,
"IRQ for invalid GPIO (bank=%d, offset=%d)\n",
bank->id, bit);
bank->bgc.write_reg(reg_base + GIO_STAT(bank->id),
stat | BIT(bit));
generic_handle_irq(irq_find_mapping(irq_domain, bit));
}
}
spin_unlock_irqrestore(&bank->bgc.lock, flags);
}
/* Each UPG GIO block has one IRQ for all banks */
static void brcmstb_gpio_irq_handler(struct irq_desc *desc)
{
struct gpio_chip *gc = irq_desc_get_handler_data(desc);
struct brcmstb_gpio_priv *priv = brcmstb_gpio_gc_to_priv(gc);
struct irq_chip *chip = irq_desc_get_chip(desc);
struct list_head *pos;
/* Interrupts weren't properly cleared during probe */
BUG_ON(!priv || !chip);
chained_irq_enter(chip, desc);
list_for_each(pos, &priv->bank_list) {
struct brcmstb_gpio_bank *bank =
list_entry(pos, struct brcmstb_gpio_bank, node);
brcmstb_gpio_irq_bank_handler(bank);
}
chained_irq_exit(chip, desc);
}
static int brcmstb_gpio_reboot(struct notifier_block *nb,
unsigned long action, void *data)
{
struct brcmstb_gpio_priv *priv =
container_of(nb, struct brcmstb_gpio_priv, reboot_notifier);
/* Enable GPIO for S5 cold boot */
if (action == SYS_POWER_OFF)
brcmstb_gpio_priv_set_wake(priv, 1);
return NOTIFY_DONE;
}
/* Make sure that the number of banks matches up between properties */
static int brcmstb_gpio_sanity_check_banks(struct device *dev,
struct device_node *np, struct resource *res)
{
int res_num_banks = resource_size(res) / GIO_BANK_SIZE;
int num_banks =
of_property_count_u32_elems(np, "brcm,gpio-bank-widths");
if (res_num_banks != num_banks) {
dev_err(dev, "Mismatch in banks: res had %d, bank-widths had %d\n",
res_num_banks, num_banks);
return -EINVAL;
} else {
return 0;
}
}
static int brcmstb_gpio_remove(struct platform_device *pdev)
{
struct brcmstb_gpio_priv *priv = platform_get_drvdata(pdev);
struct list_head *pos;
struct brcmstb_gpio_bank *bank;
int ret = 0;
if (!priv) {
dev_err(&pdev->dev, "called %s without drvdata!\n", __func__);
return -EFAULT;
}
/*
* You can lose return values below, but we report all errors, and it's
* more important to actually perform all of the steps.
*/
list_for_each(pos, &priv->bank_list) {
bank = list_entry(pos, struct brcmstb_gpio_bank, node);
ret = bgpio_remove(&bank->bgc);
if (ret)
dev_err(&pdev->dev, "gpiochip_remove fail in cleanup\n");
}
if (priv->reboot_notifier.notifier_call) {
ret = unregister_reboot_notifier(&priv->reboot_notifier);
if (ret)
dev_err(&pdev->dev,
"failed to unregister reboot notifier\n");
}
return ret;
}
static int brcmstb_gpio_of_xlate(struct gpio_chip *gc,
const struct of_phandle_args *gpiospec, u32 *flags)
{
struct brcmstb_gpio_priv *priv = brcmstb_gpio_gc_to_priv(gc);
struct brcmstb_gpio_bank *bank = brcmstb_gpio_gc_to_bank(gc);
int offset;
if (gc->of_gpio_n_cells != 2) {
WARN_ON(1);
return -EINVAL;
}
if (WARN_ON(gpiospec->args_count < gc->of_gpio_n_cells))
return -EINVAL;
offset = gpiospec->args[0] - (gc->base - priv->gpio_base);
if (offset >= gc->ngpio || offset < 0)
return -EINVAL;
if (unlikely(offset >= bank->width)) {
dev_warn_ratelimited(&priv->pdev->dev,
"Received request for invalid GPIO offset %d\n",
gpiospec->args[0]);
}
if (flags)
*flags = gpiospec->args[1];
return offset;
}
/* Before calling, must have bank->parent_irq set and gpiochip registered */
static int brcmstb_gpio_irq_setup(struct platform_device *pdev,
struct brcmstb_gpio_bank *bank)
{
struct brcmstb_gpio_priv *priv = bank->parent_priv;
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
bank->irq_chip.name = dev_name(dev);
bank->irq_chip.irq_mask = brcmstb_gpio_irq_mask;
bank->irq_chip.irq_unmask = brcmstb_gpio_irq_unmask;
bank->irq_chip.irq_set_type = brcmstb_gpio_irq_set_type;
/* Ensures that all non-wakeup IRQs are disabled at suspend */
bank->irq_chip.flags = IRQCHIP_MASK_ON_SUSPEND;
if (IS_ENABLED(CONFIG_PM_SLEEP) && !priv->can_wake &&
of_property_read_bool(np, "wakeup-source")) {
priv->parent_wake_irq = platform_get_irq(pdev, 1);
if (priv->parent_wake_irq < 0) {
dev_warn(dev,
"Couldn't get wake IRQ - GPIOs will not be able to wake from sleep");
} else {
int err;
/*
* Set wakeup capability before requesting wakeup
* interrupt, so we can process boot-time "wakeups"
* (e.g., from S5 cold boot)
*/
device_set_wakeup_capable(dev, true);
device_wakeup_enable(dev);
err = devm_request_irq(dev, priv->parent_wake_irq,
brcmstb_gpio_wake_irq_handler, 0,
"brcmstb-gpio-wake", priv);
if (err < 0) {
dev_err(dev, "Couldn't request wake IRQ");
return err;
}
priv->reboot_notifier.notifier_call =
brcmstb_gpio_reboot;
register_reboot_notifier(&priv->reboot_notifier);
priv->can_wake = true;
}
}
if (priv->can_wake)
bank->irq_chip.irq_set_wake = brcmstb_gpio_irq_set_wake;
gpiochip_irqchip_add(&bank->bgc.gc, &bank->irq_chip, 0,
handle_simple_irq, IRQ_TYPE_NONE);
gpiochip_set_chained_irqchip(&bank->bgc.gc, &bank->irq_chip,
priv->parent_irq, brcmstb_gpio_irq_handler);
return 0;
}
static int brcmstb_gpio_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
void __iomem *reg_base;
struct brcmstb_gpio_priv *priv;
struct resource *res;
struct property *prop;
const __be32 *p;
u32 bank_width;
int num_banks = 0;
int err;
static int gpio_base;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
platform_set_drvdata(pdev, priv);
INIT_LIST_HEAD(&priv->bank_list);
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
reg_base = devm_ioremap_resource(dev, res);
if (IS_ERR(reg_base))
return PTR_ERR(reg_base);
priv->gpio_base = gpio_base;
priv->reg_base = reg_base;
priv->pdev = pdev;
if (of_property_read_bool(np, "interrupt-controller")) {
priv->parent_irq = platform_get_irq(pdev, 0);
if (priv->parent_irq <= 0) {
dev_err(dev, "Couldn't get IRQ");
return -ENOENT;
}
} else {
priv->parent_irq = -ENOENT;
}
if (brcmstb_gpio_sanity_check_banks(dev, np, res))
return -EINVAL;
of_property_for_each_u32(np, "brcm,gpio-bank-widths", prop, p,
bank_width) {
struct brcmstb_gpio_bank *bank;
struct bgpio_chip *bgc;
struct gpio_chip *gc;
bank = devm_kzalloc(dev, sizeof(*bank), GFP_KERNEL);
if (!bank) {
err = -ENOMEM;
goto fail;
}
bank->parent_priv = priv;
bank->id = num_banks;
if (bank_width <= 0 || bank_width > MAX_GPIO_PER_BANK) {
dev_err(dev, "Invalid bank width %d\n", bank_width);
goto fail;
} else {
bank->width = bank_width;
}
/*
* Regs are 4 bytes wide, have data reg, no set/clear regs,
* and direction bits have 0 = output and 1 = input
*/
bgc = &bank->bgc;
err = bgpio_init(bgc, dev, 4,
reg_base + GIO_DATA(bank->id),
NULL, NULL, NULL,
reg_base + GIO_IODIR(bank->id), 0);
if (err) {
dev_err(dev, "bgpio_init() failed\n");
goto fail;
}
gc = &bgc->gc;
gc->of_node = np;
gc->owner = THIS_MODULE;
gc->label = np->full_name;
gc->base = gpio_base;
gc->of_gpio_n_cells = 2;
gc->of_xlate = brcmstb_gpio_of_xlate;
/* not all ngpio lines are valid, will use bank width later */
gc->ngpio = MAX_GPIO_PER_BANK;
/*
* Mask all interrupts by default, since wakeup interrupts may
* be retained from S5 cold boot
*/
bank->bgc.write_reg(reg_base + GIO_MASK(bank->id), 0);
err = gpiochip_add(gc);
if (err) {
dev_err(dev, "Could not add gpiochip for bank %d\n",
bank->id);
goto fail;
}
gpio_base += gc->ngpio;
if (priv->parent_irq > 0) {
err = brcmstb_gpio_irq_setup(pdev, bank);
if (err)
goto fail;
}
dev_dbg(dev, "bank=%d, base=%d, ngpio=%d, width=%d\n", bank->id,
gc->base, gc->ngpio, bank->width);
/* Everything looks good, so add bank to list */
list_add(&bank->node, &priv->bank_list);
num_banks++;
}
dev_info(dev, "Registered %d banks (GPIO(s): %d-%d)\n",
num_banks, priv->gpio_base, gpio_base - 1);
return 0;
fail:
(void) brcmstb_gpio_remove(pdev);
return err;
}
static const struct of_device_id brcmstb_gpio_of_match[] = {
{ .compatible = "brcm,brcmstb-gpio" },
{},
};
MODULE_DEVICE_TABLE(of, brcmstb_gpio_of_match);
static struct platform_driver brcmstb_gpio_driver = {
.driver = {
.name = "brcmstb-gpio",
.of_match_table = brcmstb_gpio_of_match,
},
.probe = brcmstb_gpio_probe,
.remove = brcmstb_gpio_remove,
};
module_platform_driver(brcmstb_gpio_driver);
MODULE_AUTHOR("Gregory Fong");
MODULE_DESCRIPTION("Driver for Broadcom BRCMSTB SoC UPG GPIO");
MODULE_LICENSE("GPL v2");