/*
* Toumaz Xenif TZ1090 PDC GPIO handling.
*
* Copyright (C) 2012-2013 Imagination Technologies Ltd.
*
* 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/bitops.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of_irq.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_device.h>
#include <linux/slab.h>
#include <linux/syscore_ops.h>
#include <asm/global_lock.h>
/* Register offsets from SOC_GPIO_CONTROL0 */
#define REG_SOC_GPIO_CONTROL0 0x00
#define REG_SOC_GPIO_CONTROL1 0x04
#define REG_SOC_GPIO_CONTROL2 0x08
#define REG_SOC_GPIO_CONTROL3 0x0c
#define REG_SOC_GPIO_STATUS 0x80
/* PDC GPIOs go after normal GPIOs */
#define GPIO_PDC_BASE 90
#define GPIO_PDC_NGPIO 7
/* Out of PDC gpios, only syswakes have irqs */
#define GPIO_PDC_IRQ_FIRST 2
#define GPIO_PDC_NIRQ 3
/**
* struct tz1090_pdc_gpio - GPIO bank private data
* @chip: Generic GPIO chip for GPIO bank
* @reg: Base of registers, offset for this GPIO bank
* @irq: IRQ numbers for Syswake GPIOs
*
* This is the main private data for the PDC GPIO driver. It encapsulates a
* gpio_chip, and the callbacks for the gpio_chip can access the private data
* with the to_pdc() macro below.
*/
struct tz1090_pdc_gpio {
struct gpio_chip chip;
void __iomem *reg;
int irq[GPIO_PDC_NIRQ];
};
#define to_pdc(c) container_of(c, struct tz1090_pdc_gpio, chip)
/* Register accesses into the PDC MMIO area */
static inline void pdc_write(struct tz1090_pdc_gpio *priv, unsigned int reg_offs,
unsigned int data)
{
writel(data, priv->reg + reg_offs);
}
static inline unsigned int pdc_read(struct tz1090_pdc_gpio *priv,
unsigned int reg_offs)
{
return readl(priv->reg + reg_offs);
}
/* Generic GPIO interface */
static int tz1090_pdc_gpio_direction_input(struct gpio_chip *chip,
unsigned int offset)
{
struct tz1090_pdc_gpio *priv = to_pdc(chip);
u32 value;
int lstat;
__global_lock2(lstat);
value = pdc_read(priv, REG_SOC_GPIO_CONTROL1);
value |= BIT(offset);
pdc_write(priv, REG_SOC_GPIO_CONTROL1, value);
__global_unlock2(lstat);
return 0;
}
static int tz1090_pdc_gpio_direction_output(struct gpio_chip *chip,
unsigned int offset,
int output_value)
{
struct tz1090_pdc_gpio *priv = to_pdc(chip);
u32 value;
int lstat;
__global_lock2(lstat);
/* EXT_POWER doesn't seem to have an output value bit */
if (offset < 6) {
value = pdc_read(priv, REG_SOC_GPIO_CONTROL0);
if (output_value)
value |= BIT(offset);
else
value &= ~BIT(offset);
pdc_write(priv, REG_SOC_GPIO_CONTROL0, value);
}
value = pdc_read(priv, REG_SOC_GPIO_CONTROL1);
value &= ~BIT(offset);
pdc_write(priv, REG_SOC_GPIO_CONTROL1, value);
__global_unlock2(lstat);
return 0;
}
static int tz1090_pdc_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
struct tz1090_pdc_gpio *priv = to_pdc(chip);
return pdc_read(priv, REG_SOC_GPIO_STATUS) & BIT(offset);
}
static void tz1090_pdc_gpio_set(struct gpio_chip *chip, unsigned int offset,
int output_value)
{
struct tz1090_pdc_gpio *priv = to_pdc(chip);
u32 value;
int lstat;
/* EXT_POWER doesn't seem to have an output value bit */
if (offset >= 6)
return;
__global_lock2(lstat);
value = pdc_read(priv, REG_SOC_GPIO_CONTROL0);
if (output_value)
value |= BIT(offset);
else
value &= ~BIT(offset);
pdc_write(priv, REG_SOC_GPIO_CONTROL0, value);
__global_unlock2(lstat);
}
static int tz1090_pdc_gpio_request(struct gpio_chip *chip, unsigned int offset)
{
return pinctrl_request_gpio(chip->base + offset);
}
static void tz1090_pdc_gpio_free(struct gpio_chip *chip, unsigned int offset)
{
pinctrl_free_gpio(chip->base + offset);
}
static int tz1090_pdc_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
{
struct tz1090_pdc_gpio *priv = to_pdc(chip);
unsigned int syswake = offset - GPIO_PDC_IRQ_FIRST;
int irq;
/* only syswakes have irqs */
if (syswake >= GPIO_PDC_NIRQ)
return -EINVAL;
irq = priv->irq[syswake];
if (!irq)
return -EINVAL;
return irq;
}
static int tz1090_pdc_gpio_probe(struct platform_device *pdev)
{
struct device_node *np = pdev->dev.of_node;
struct resource *res_regs;
struct tz1090_pdc_gpio *priv;
unsigned int i;
if (!np) {
dev_err(&pdev->dev, "must be instantiated via devicetree\n");
return -ENOENT;
}
res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res_regs) {
dev_err(&pdev->dev, "cannot find registers resource\n");
return -ENOENT;
}
priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
if (!priv) {
dev_err(&pdev->dev, "unable to allocate driver data\n");
return -ENOMEM;
}
/* Ioremap the registers */
priv->reg = devm_ioremap(&pdev->dev, res_regs->start,
resource_size(res_regs));
if (!priv->reg) {
dev_err(&pdev->dev, "unable to ioremap registers\n");
return -ENOMEM;
}
/* Set up GPIO chip */
priv->chip.label = "tz1090-pdc-gpio";
priv->chip.dev = &pdev->dev;
priv->chip.direction_input = tz1090_pdc_gpio_direction_input;
priv->chip.direction_output = tz1090_pdc_gpio_direction_output;
priv->chip.get = tz1090_pdc_gpio_get;
priv->chip.set = tz1090_pdc_gpio_set;
priv->chip.free = tz1090_pdc_gpio_free;
priv->chip.request = tz1090_pdc_gpio_request;
priv->chip.to_irq = tz1090_pdc_gpio_to_irq;
priv->chip.of_node = np;
/* GPIO numbering */
priv->chip.base = GPIO_PDC_BASE;
priv->chip.ngpio = GPIO_PDC_NGPIO;
/* Map the syswake irqs */
for (i = 0; i < GPIO_PDC_NIRQ; ++i)
priv->irq[i] = irq_of_parse_and_map(np, i);
/* Add the GPIO bank */
gpiochip_add(&priv->chip);
return 0;
}
static struct of_device_id tz1090_pdc_gpio_of_match[] = {
{ .compatible = "img,tz1090-pdc-gpio" },
{ },
};
static struct platform_driver tz1090_pdc_gpio_driver = {
.driver = {
.name = "tz1090-pdc-gpio",
.of_match_table = tz1090_pdc_gpio_of_match,
},
.probe = tz1090_pdc_gpio_probe,
};
static int __init tz1090_pdc_gpio_init(void)
{
return platform_driver_register(&tz1090_pdc_gpio_driver);
}
subsys_initcall(tz1090_pdc_gpio_init);
