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linux/drivers/gpio/gpio-ep93xx.c
Shawn Guo 3e11f7b840 gpio/generic: initialize basic_mmio_gpio shadow variables properly 
It fixes the issue in gpio-generic that commit fb14921 (gpio/mxc: add
missing initialization of basic_mmio_gpio shadow variables) manged to
fix in gpio-mxc driver, so that other platform specific drivers do not
suffer from the same problem over and over again.

Changes since v1:
* Turn the last parameter of bgpio_init() "bool big_endian" into
  "unsigned long flags" and give those really quirky hardwares a
  chance to tell that reg_set and reg_dir are unreadable.

Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
[grant.likely: Fix big-endian usage to explicitly set BBGPIOF_BIG_ENDIAN]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-05-19 12:17:35 -06:00

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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/gpio.h>
#include <linux/irq.h>
#include <linux/slab.h>
#include <linux/basic_mmio_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 bgpio_chip bgc[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);
__raw_writeb(0, EP93XX_GPIO_REG(int_en_register_offset[port]));
__raw_writeb(gpio_int_type2[port],
EP93XX_GPIO_REG(int_type2_register_offset[port]));
__raw_writeb(gpio_int_type1[port],
EP93XX_GPIO_REG(int_type1_register_offset[port]));
__raw_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;
__raw_writeb(gpio_int_debounce[port],
EP93XX_GPIO_REG(int_debounce_register_offset[port]));
}
static void ep93xx_gpio_ab_irq_handler(unsigned int irq, struct irq_desc *desc)
{
unsigned char status;
int i;
status = __raw_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 = __raw_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(unsigned int irq, 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})
*/
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);
}
__raw_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);
__raw_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->irq, 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);
set_irq_flags(gpio_irq, IRQF_VALID);
}
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_debounce(struct gpio_chip *chip,
unsigned offset, unsigned debounce)
{
int gpio = chip->base + offset;
int irq = gpio_to_irq(gpio);
if (irq < 0)
return -EINVAL;
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 bgpio_chip *bgc, 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(bgc, dev, 1, data, NULL, NULL, dir, NULL, 0);
if (err)
return err;
bgc->gc.label = bank->label;
bgc->gc.base = bank->base;
if (bank->has_debounce) {
bgc->gc.set_debounce = ep93xx_gpio_set_debounce;
bgc->gc.to_irq = ep93xx_gpio_to_irq;
}
return gpiochip_add(&bgc->gc);
}
static int __devinit ep93xx_gpio_probe(struct platform_device *pdev)
{
struct ep93xx_gpio *ep93xx_gpio;
struct resource *res;
void __iomem *mmio;
int i;
int ret;
ep93xx_gpio = kzalloc(sizeof(*ep93xx_gpio), GFP_KERNEL);
if (!ep93xx_gpio)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
ret = -ENXIO;
goto exit_free;
}
if (!request_mem_region(res->start, resource_size(res), pdev->name)) {
ret = -EBUSY;
goto exit_free;
}
mmio = ioremap(res->start, resource_size(res));
if (!mmio) {
ret = -ENXIO;
goto exit_release;
}
ep93xx_gpio->mmio_base = mmio;
for (i = 0; i < ARRAY_SIZE(ep93xx_gpio_banks); i++) {
struct bgpio_chip *bgc = &ep93xx_gpio->bgc[i];
struct ep93xx_gpio_bank *bank = &ep93xx_gpio_banks[i];
if (ep93xx_gpio_add_bank(bgc, &pdev->dev, mmio, bank))
dev_warn(&pdev->dev, "Unable to add gpio bank %s\n",
bank->label);
}
ep93xx_gpio_init_irq();
return 0;
exit_release:
release_mem_region(res->start, resource_size(res));
exit_free:
kfree(ep93xx_gpio);
dev_info(&pdev->dev, "%s failed with errno %d\n", __func__, ret);
return ret;
}
static struct platform_driver ep93xx_gpio_driver = {
.driver = {
.name = "gpio-ep93xx",
.owner = THIS_MODULE,
},
.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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