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alistair23-linux/drivers/gpio/gpio-ep93xx.c
Mika Westerberg 2956b5d94a pinctrl / gpio: Introduce .set_config() callback for GPIO chips 
Currently we already have two pin configuration related callbacks
available for GPIO chips .set_single_ended() and .set_debounce(). In
future we expect to have even more, which does not scale well if we need
to add yet another callback to the GPIO chip structure for each possible
configuration parameter.

Better solution is to reuse what we already have available in the
generic pinconf.

To support this, we introduce a new .set_config() callback for GPIO
chips. The callback takes a single packed pin configuration value as
parameter. This can then be extended easily beyond what is currently
supported by just adding new types to the generic pinconf enum.

If the GPIO driver is backed up by a pinctrl driver the GPIO driver can
just assign gpiochip_generic_config() (introduced in this patch) to
.set_config and that will take care configuration requests are directed
to the pinctrl driver.

We then convert the existing drivers over .set_config() and finally
remove the .set_single_ended() and .set_debounce() callbacks.

Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-26 15:27:37 +01:00

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/*
* 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
*
* 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/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>
/* FIXME: this is here for gpio_to_irq() - get rid of this! */
#include <linux/gpio.h>
#include <mach/hardware.h>
#include <mach/gpio-ep93xx.h>
#define irq_to_gpio(irq) ((irq) - gpio_to_irq(0))
struct ep93xx_gpio {
void __iomem *mmio_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(unsigned port)
{
BUG_ON(port > 2);
writeb_relaxed(0, EP93XX_GPIO_REG(int_en_register_offset[port]));
writeb_relaxed(gpio_int_type2[port],
EP93XX_GPIO_REG(int_type2_register_offset[port]));
writeb_relaxed(gpio_int_type1[port],
EP93XX_GPIO_REG(int_type1_register_offset[port]));
writeb(gpio_int_unmasked[port] & gpio_int_enabled[port],
EP93XX_GPIO_REG(int_en_register_offset[port]));
}
static void ep93xx_gpio_int_debounce(unsigned int irq, bool enable)
{
int line = irq_to_gpio(irq);
int port = line >> 3;
int port_mask = 1 << (line & 7);
if (enable)
gpio_int_debounce[port] |= port_mask;
else
gpio_int_debounce[port] &= ~port_mask;
writeb(gpio_int_debounce[port],
EP93XX_GPIO_REG(int_debounce_register_offset[port]));
}
static void ep93xx_gpio_ab_irq_handler(struct irq_desc *desc)
{
unsigned char status;
int i;
status = readb(EP93XX_GPIO_A_INT_STATUS);
for (i = 0; i < 8; i++) {
if (status & (1 << i)) {
int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_A(0)) + i;
generic_handle_irq(gpio_irq);
}
}
status = readb(EP93XX_GPIO_B_INT_STATUS);
for (i = 0; i < 8; i++) {
if (status & (1 << i)) {
int gpio_irq = gpio_to_irq(EP93XX_GPIO_LINE_B(0)) + i;
generic_handle_irq(gpio_irq);
}
}
}
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 -> gpio_to_irq(EP93XX_GPIO_LINE_F({0..7})
*/
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 = gpio_to_irq(EP93XX_GPIO_LINE_F(0)) + port_f_idx;
generic_handle_irq(gpio_irq);
}
static void ep93xx_gpio_irq_ack(struct irq_data *d)
{
int line = irq_to_gpio(d->irq);
int port = line >> 3;
int port_mask = 1 << (line & 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(port);
}
writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
}
static void ep93xx_gpio_irq_mask_ack(struct irq_data *d)
{
int line = irq_to_gpio(d->irq);
int port = line >> 3;
int port_mask = 1 << (line & 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(port);
writeb(port_mask, EP93XX_GPIO_REG(eoi_register_offset[port]));
}
static void ep93xx_gpio_irq_mask(struct irq_data *d)
{
int line = irq_to_gpio(d->irq);
int port = line >> 3;
gpio_int_unmasked[port] &= ~(1 << (line & 7));
ep93xx_gpio_update_int_params(port);
}
static void ep93xx_gpio_irq_unmask(struct irq_data *d)
{
int line = irq_to_gpio(d->irq);
int port = line >> 3;
gpio_int_unmasked[port] |= 1 << (line & 7);
ep93xx_gpio_update_int_params(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)
{
const int gpio = irq_to_gpio(d->irq);
const int port = gpio >> 3;
const int port_mask = 1 << (gpio & 7);
irq_flow_handler_t handler;
gpio_direction_input(gpio);
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 (gpio_get_value(gpio))
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(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 void ep93xx_gpio_init_irq(void)
{
int gpio_irq;
for (gpio_irq = gpio_to_irq(0);
gpio_irq <= gpio_to_irq(EP93XX_GPIO_LINE_MAX_IRQ); ++gpio_irq) {
irq_set_chip_and_handler(gpio_irq, &ep93xx_gpio_irq_chip,
handle_level_irq);
irq_clear_status_flags(gpio_irq, IRQ_NOREQUEST);
}
irq_set_chained_handler(IRQ_EP93XX_GPIO_AB,
ep93xx_gpio_ab_irq_handler);
irq_set_chained_handler(IRQ_EP93XX_GPIO0MUX,
ep93xx_gpio_f_irq_handler);
irq_set_chained_handler(IRQ_EP93XX_GPIO1MUX,
ep93xx_gpio_f_irq_handler);
irq_set_chained_handler(IRQ_EP93XX_GPIO2MUX,
ep93xx_gpio_f_irq_handler);
irq_set_chained_handler(IRQ_EP93XX_GPIO3MUX,
ep93xx_gpio_f_irq_handler);
irq_set_chained_handler(IRQ_EP93XX_GPIO4MUX,
ep93xx_gpio_f_irq_handler);
irq_set_chained_handler(IRQ_EP93XX_GPIO5MUX,
ep93xx_gpio_f_irq_handler);
irq_set_chained_handler(IRQ_EP93XX_GPIO6MUX,
ep93xx_gpio_f_irq_handler);
irq_set_chained_handler(IRQ_EP93XX_GPIO7MUX,
ep93xx_gpio_f_irq_handler);
}
/*************************************************************************
* gpiolib interface for EP93xx on-chip GPIOs
*************************************************************************/
struct ep93xx_gpio_bank {
const char *label;
int data;
int dir;
int base;
bool has_debounce;
};
#define EP93XX_GPIO_BANK(_label, _data, _dir, _base, _debounce) \
{ \
.label = _label, \
.data = _data, \
.dir = _dir, \
.base = _base, \
.has_debounce = _debounce, \
}
static struct ep93xx_gpio_bank ep93xx_gpio_banks[] = {
EP93XX_GPIO_BANK("A", 0x00, 0x10, 0, true),
EP93XX_GPIO_BANK("B", 0x04, 0x14, 8, true),
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),
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 *chip, unsigned offset,
unsigned long config)
{
int gpio = chip->base + offset;
int irq = gpio_to_irq(gpio);
u32 debounce;
if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
return -ENOTSUPP;
if (irq < 0)
return -EINVAL;
debounce = pinconf_to_config_argument(config);
ep93xx_gpio_int_debounce(irq, debounce ? true : false);
return 0;
}
/*
* Map GPIO A0..A7 (0..7) to irq 64..71,
* B0..B7 (7..15) to irq 72..79, and
* F0..F7 (16..24) to irq 80..87.
*/
static int ep93xx_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
int gpio = chip->base + offset;
if (gpio > EP93XX_GPIO_LINE_MAX_IRQ)
return -EINVAL;
return 64 + gpio;
}
static int ep93xx_gpio_add_bank(struct gpio_chip *gc, struct device *dev,
void __iomem *mmio_base, struct ep93xx_gpio_bank *bank)
{
void __iomem *data = mmio_base + bank->data;
void __iomem *dir = mmio_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_debounce) {
gc->set_config = ep93xx_gpio_set_config;
gc->to_irq = ep93xx_gpio_to_irq;
}
return devm_gpiochip_add_data(dev, gc, NULL);
}
static int ep93xx_gpio_probe(struct platform_device *pdev)
{
struct ep93xx_gpio *ep93xx_gpio;
struct resource *res;
int i;
struct device *dev = &pdev->dev;
ep93xx_gpio = devm_kzalloc(dev, sizeof(struct ep93xx_gpio), GFP_KERNEL);
if (!ep93xx_gpio)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
ep93xx_gpio->mmio_base = devm_ioremap_resource(dev, res);
if (IS_ERR(ep93xx_gpio->mmio_base))
return PTR_ERR(ep93xx_gpio->mmio_base);
for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
struct gpio_chip *gc = &ep93xx_gpio->gc[i];
struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];
if (ep93xx_gpio_add_bank(gc, &pdev->dev,
ep93xx_gpio->mmio_base, bank))
dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
bank->label);
}
ep93xx_gpio_init_irq();
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");
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