gpio-ep93xx.c
// SPDX-License-Identifier: GPL-2.0
/*
* Generic EP93xx GPIO handling
*
* Copyright (c) 2008 Ryan Mallon
* Copyright (c) 2011 H Hartley Sweeten <hsweeten@visionengravers.com>
*
* Based on code originally from:
* linux/arch/arm/mach-ep93xx/core.c
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/gpio/driver.h>
#include <linux/bitops.h>
#define EP93XX_GPIO_F_INT_STATUS 0x5c
#define EP93XX_GPIO_A_INT_STATUS 0xa0
#define EP93XX_GPIO_B_INT_STATUS 0xbc
/* Maximum value for gpio line identifiers */
#define EP93XX_GPIO_LINE_MAX 63
/* Maximum value for irq capable line identifiers */
#define EP93XX_GPIO_LINE_MAX_IRQ 23
/*
* Static mapping of GPIO bank F IRQS:
* F0..F7 (16..24) to irq 80..87.
*/
#define EP93XX_GPIO_F_IRQ_BASE 80
struct ep93xx_gpio {
void __iomem *base;
struct gpio_chip gc[8];
};
/*************************************************************************
* Interrupt handling for EP93xx on-chip GPIOs
*************************************************************************/
static unsigned char gpio_int_unmasked[3];
static unsigned char gpio_int_enabled[3];
static unsigned char gpio_int_type1[3];
static unsigned char gpio_int_type2[3];
static unsigned char gpio_int_debounce[3];
/* Port ordering is: A B F */
static const u8 int_type1_register_offset[3] = { 0x90, 0xac, 0x4c };
static const u8 int_type2_register_offset[3] = { 0x94, 0xb0, 0x50 };
static const u8 eoi_register_offset[3] = { 0x98, 0xb4, 0x54 };
static const u8 int_en_register_offset[3] = { 0x9c, 0xb8, 0x58 };
static const u8 int_debounce_register_offset[3] = { 0xa8, 0xc4, 0x64 };
static void ep93xx_gpio_update_int_params(struct ep93xx_gpio *epg, unsigned port)
{
BUG_ON(port > 2);
writeb_relaxed(0, epg->base + int_en_register_offset[port]);
writeb_relaxed(gpio_int_type2[port],
epg->base + int_type2_register_offset[port]);
writeb_relaxed(gpio_int_type1[port],
epg->base + int_type1_register_offset[port]);
writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
epg->base + int_en_register_offset[port]);
}
static int ep93xx_gpio_port(struct gpio_chip *gc)
{
struct ep93xx_gpio *epg = gpiochip_get_data(gc);
int port = 0;
while (port < ARRAY_SIZE(epg->gc) && gc != &epg->gc[port])
port++;
/* This should not happen but is there as a last safeguard */
if (port == ARRAY_SIZE(epg->gc)) {
pr_crit("can't find the GPIO port\n");
return 0;
}
return port;
}
static void ep93xx_gpio_int_debounce(struct gpio_chip *gc,
unsigned int offset, bool enable)
{
struct ep93xx_gpio *epg = gpiochip_get_data(gc);
int port = ep93xx_gpio_port(gc);
int port_mask = BIT(offset);
if (enable)
gpio_int_debounce[port] |= port_mask;
else
gpio_int_debounce[port] &= ~port_mask;
writeb(gpio_int_debounce[port],
epg->base + int_debounce_register_offset[port]);
}
static void ep93xx_gpio_ab_irq_handler(struct irq_desc *desc)
{
struct gpio_chip *gc = irq_desc_get_handler_data(desc);
struct ep93xx_gpio *epg = gpiochip_get_data(gc);
struct irq_chip *irqchip = irq_desc_get_chip(desc);
unsigned long stat;
int offset;
chained_irq_enter(irqchip, desc);
/*
* Dispatch the IRQs to the irqdomain of each A and B
* gpiochip irqdomains depending on what has fired.
* The tricky part is that the IRQ line is shared
* between bank A and B and each has their own gpiochip.
*/
stat = readb(epg->base + EP93XX_GPIO_A_INT_STATUS);
for_each_set_bit(offset, &stat, 8)
generic_handle_irq(irq_find_mapping(epg->gc[0].irq.domain,
offset));
stat = readb(epg->base + EP93XX_GPIO_B_INT_STATUS);
for_each_set_bit(offset, &stat, 8)
generic_handle_irq(irq_find_mapping(epg->gc[1].irq.domain,
offset));
chained_irq_exit(irqchip, desc);
}
static void ep93xx_gpio_f_irq_handler(struct irq_desc *desc)
{
/*
* map discontiguous hw irq range to continuous sw irq range:
*
* IRQ_EP93XX_GPIO{0..7}MUX -> EP93XX_GPIO_LINE_F{0..7}
*/
struct irq_chip *irqchip = irq_desc_get_chip(desc);
unsigned int irq = irq_desc_get_irq(desc);
int port_f_idx = ((irq + 1) & 7) ^ 4; /* {19..22,47..50} -> {0..7} */
int gpio_irq = EP93XX_GPIO_F_IRQ_BASE + port_f_idx;
chained_irq_enter(irqchip, desc);
generic_handle_irq(gpio_irq);
chained_irq_exit(irqchip, desc);
}
static void ep93xx_gpio_irq_ack(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct ep93xx_gpio *epg = gpiochip_get_data(gc);
int port = ep93xx_gpio_port(gc);
int port_mask = BIT(d->irq & 7);
if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH) {
gpio_int_type2[port] ^= port_mask; /* switch edge direction */
ep93xx_gpio_update_int_params(epg, port);
}
writeb(port_mask, epg->base + eoi_register_offset[port]);
}
static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct ep93xx_gpio *epg = gpiochip_get_data(gc);
int port = ep93xx_gpio_port(gc);
int port_mask = BIT(d->irq & 7);
if (irqd_get_trigger_type(d) == IRQ_TYPE_EDGE_BOTH)
gpio_int_type2[port] ^= port_mask; /* switch edge direction */
gpio_int_unmasked[port] &= ~port_mask;
ep93xx_gpio_update_int_params(epg, port);
writeb(port_mask, epg->base + eoi_register_offset[port]);
}
static void ep93xx_gpio_irq_mask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct ep93xx_gpio *epg = gpiochip_get_data(gc);
int port = ep93xx_gpio_port(gc);
gpio_int_unmasked[port] &= ~BIT(d->irq & 7);
ep93xx_gpio_update_int_params(epg, port);
}
static void ep93xx_gpio_irq_unmask(struct irq_data *d)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct ep93xx_gpio *epg = gpiochip_get_data(gc);
int port = ep93xx_gpio_port(gc);
gpio_int_unmasked[port] |= BIT(d->irq & 7);
ep93xx_gpio_update_int_params(epg, port);
}
/*
* gpio_int_type1 controls whether the interrupt is level (0) or
* edge (1) triggered, while gpio_int_type2 controls whether it
* triggers on low/falling (0) or high/rising (1).
*/
static int ep93xx_gpio_irq_type(struct irq_data *d, unsigned int type)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
struct ep93xx_gpio *epg = gpiochip_get_data(gc);
int port = ep93xx_gpio_port(gc);
int offset = d->irq & 7;
int port_mask = BIT(offset);
irq_flow_handler_t handler;
gc->direction_input(gc, offset);
switch (type) {
case IRQ_TYPE_EDGE_RISING:
gpio_int_type1[port] |= port_mask;
gpio_int_type2[port] |= port_mask;
handler = handle_edge_irq;
break;
case IRQ_TYPE_EDGE_FALLING:
gpio_int_type1[port] |= port_mask;
gpio_int_type2[port] &= ~port_mask;
handler = handle_edge_irq;
break;
case IRQ_TYPE_LEVEL_HIGH:
gpio_int_type1[port] &= ~port_mask;
gpio_int_type2[port] |= port_mask;
handler = handle_level_irq;
break;
case IRQ_TYPE_LEVEL_LOW:
gpio_int_type1[port] &= ~port_mask;
gpio_int_type2[port] &= ~port_mask;
handler = handle_level_irq;
break;
case IRQ_TYPE_EDGE_BOTH:
gpio_int_type1[port] |= port_mask;
/* set initial polarity based on current input level */
if (gc->get(gc, offset))
gpio_int_type2[port] &= ~port_mask; /* falling */
else
gpio_int_type2[port] |= port_mask; /* rising */
handler = handle_edge_irq;
break;
default:
return -EINVAL;
}
irq_set_handler_locked(d, handler);
gpio_int_enabled[port] |= port_mask;
ep93xx_gpio_update_int_params(epg, port);
return 0;
}
static struct irq_chip ep93xx_gpio_irq_chip = {
.name = "GPIO",
.irq_ack = ep93xx_gpio_irq_ack,
.irq_mask_ack = ep93xx_gpio_irq_mask_ack,
.irq_mask = ep93xx_gpio_irq_mask,
.irq_unmask = ep93xx_gpio_irq_unmask,
.irq_set_type = ep93xx_gpio_irq_type,
};
static int ep93xx_gpio_init_irq(struct platform_device *pdev,
struct ep93xx_gpio *epg)
{
int ab_parent_irq = platform_get_irq(pdev, 0);
struct device *dev = &pdev->dev;
int gpio_irq;
int ret;
int i;
/* The A bank */
ret = gpiochip_irqchip_add(&epg->gc[0], &ep93xx_gpio_irq_chip,
64, handle_level_irq,
IRQ_TYPE_NONE);
if (ret) {
dev_err(dev, "Could not add irqchip 0\n");
return ret;
}
gpiochip_set_chained_irqchip(&epg->gc[0], &ep93xx_gpio_irq_chip,
ab_parent_irq,
ep93xx_gpio_ab_irq_handler);
/* The B bank */
ret = gpiochip_irqchip_add(&epg->gc[1], &ep93xx_gpio_irq_chip,
72, handle_level_irq,
IRQ_TYPE_NONE);
if (ret) {
dev_err(dev, "Could not add irqchip 1\n");
return ret;
}
gpiochip_set_chained_irqchip(&epg->gc[1], &ep93xx_gpio_irq_chip,
ab_parent_irq,
ep93xx_gpio_ab_irq_handler);
/* The F bank */
for (i = 0; i < 8; i++) {
gpio_irq = EP93XX_GPIO_F_IRQ_BASE + i;
irq_set_chip_data(gpio_irq, &epg->gc[5]);
irq_set_chip_and_handler(gpio_irq, &ep93xx_gpio_irq_chip,
handle_level_irq);
irq_clear_status_flags(gpio_irq, IRQ_NOREQUEST);
}
for (i = 1; i <= 8; i++)
irq_set_chained_handler_and_data(platform_get_irq(pdev, i),
ep93xx_gpio_f_irq_handler,
&epg->gc[i]);
return 0;
}
/*************************************************************************
* gpiolib interface for EP93xx on-chip GPIOs
*************************************************************************/
struct ep93xx_gpio_bank {
const char *label;
int data;
int dir;
int base;
bool has_irq;
};
#define EP93XX_GPIO_BANK(_label, _data, _dir, _base, _has_irq) \
{ \
.label = _label, \
.data = _data, \
.dir = _dir, \
.base = _base, \
.has_irq = _has_irq, \
}
static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = {
EP93XX_GPIO_BANK("A", 0x00, 0x10, 0, true), /* Bank A has 8 IRQs */
EP93XX_GPIO_BANK("B", 0x04, 0x14, 8, true), /* Bank B has 8 IRQs */
EP93XX_GPIO_BANK("C", 0x08, 0x18, 40, false),
EP93XX_GPIO_BANK("D", 0x0c, 0x1c, 24, false),
EP93XX_GPIO_BANK("E", 0x20, 0x24, 32, false),
EP93XX_GPIO_BANK("F", 0x30, 0x34, 16, true), /* Bank F has 8 IRQs */
EP93XX_GPIO_BANK("G", 0x38, 0x3c, 48, false),
EP93XX_GPIO_BANK("H", 0x40, 0x44, 56, false),
};
static int ep93xx_gpio_set_config(struct gpio_chip *gc, unsigned offset,
unsigned long config)
{
u32 debounce;
if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
return -ENOTSUPP;
debounce = pinconf_to_config_argument(config);
ep93xx_gpio_int_debounce(gc, offset, debounce ? true : false);
return 0;
}
static int ep93xx_gpio_f_to_irq(struct gpio_chip *gc, unsigned offset)
{
return EP93XX_GPIO_F_IRQ_BASE + offset;
}
static int ep93xx_gpio_add_bank(struct gpio_chip *gc, struct device *dev,
struct ep93xx_gpio *epg,
struct ep93xx_gpio_bank *bank)
{
void __iomem *data = epg->base + bank->data;
void __iomem *dir = epg->base + bank->dir;
int err;
err = bgpio_init(gc, dev, 1, data, NULL, NULL, dir, NULL, 0);
if (err)
return err;
gc->label = bank->label;
gc->base = bank->base;
if (bank->has_irq)
gc->set_config = ep93xx_gpio_set_config;
return devm_gpiochip_add_data(dev, gc, epg);
}
static int ep93xx_gpio_probe(struct platform_device *pdev)
{
struct ep93xx_gpio *epg;
struct resource *res;
int i;
struct device *dev = &pdev->dev;
epg = devm_kzalloc(dev, sizeof(*epg), GFP_KERNEL);
if (!epg)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
epg->base = devm_ioremap_resource(dev, res);
if (IS_ERR(epg->base))
return PTR_ERR(epg->base);
for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
struct gpio_chip *gc = &epg->gc[i];
struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];
if (ep93xx_gpio_add_bank(gc, &pdev->dev, epg, bank))
dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
bank->label);
/* Only bank F has especially funky IRQ handling */
if (i == 5)
gc->to_irq = ep93xx_gpio_f_to_irq;
}
ep93xx_gpio_init_irq(pdev, epg);
return 0;
}
static struct platform_driver ep93xx_gpio_driver = {
.driver = {
.name = "gpio-ep93xx",
},
.probe = ep93xx_gpio_probe,
};
static int __init ep93xx_gpio_init(void)
{
return platform_driver_register(&ep93xx_gpio_driver);
}
postcore_initcall(ep93xx_gpio_init);
MODULE_AUTHOR("Ryan Mallon <ryan@bluewatersys.com> "
"H Hartley Sweeten <hsweeten@visionengravers.com>");
MODULE_DESCRIPTION("EP93XX GPIO driver");
MODULE_LICENSE("GPL");