linux-stable/drivers/gpio/gpio-sa1100.c
Russell King c65d1fd350 gpio: sa1100: implement get_direction method
Allow gpiolib to read back the current IO direction configuration by
implementing the .get_direction callback.  This, in part, allows
debugfs to report the complete true hardware state rather than the
software state.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-03-24 14:04:37 +01:00

328 lines
7.4 KiB
C

/*
* linux/arch/arm/mach-sa1100/gpio.c
*
* Generic SA-1100 GPIO handling
*
* 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/gpio.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/io.h>
#include <linux/syscore_ops.h>
#include <soc/sa1100/pwer.h>
#include <mach/hardware.h>
#include <mach/irqs.h>
struct sa1100_gpio_chip {
struct gpio_chip chip;
void __iomem *membase;
int irqbase;
u32 irqmask;
u32 irqrising;
u32 irqfalling;
u32 irqwake;
};
#define sa1100_gpio_chip(x) container_of(x, struct sa1100_gpio_chip, chip)
enum {
R_GPLR = 0x00,
R_GPDR = 0x04,
R_GPSR = 0x08,
R_GPCR = 0x0c,
R_GRER = 0x10,
R_GFER = 0x14,
R_GEDR = 0x18,
R_GAFR = 0x1c,
};
static int sa1100_gpio_get(struct gpio_chip *chip, unsigned offset)
{
return readl_relaxed(sa1100_gpio_chip(chip)->membase + R_GPLR) &
BIT(offset);
}
static void sa1100_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
int reg = value ? R_GPSR : R_GPCR;
writel_relaxed(BIT(offset), sa1100_gpio_chip(chip)->membase + reg);
}
static int sa1100_get_direction(struct gpio_chip *chip, unsigned offset)
{
void __iomem *gpdr = sa1100_gpio_chip(chip)->membase + R_GPDR;
return !(readl_relaxed(gpdr) & BIT(offset));
}
static int sa1100_direction_input(struct gpio_chip *chip, unsigned offset)
{
void __iomem *gpdr = sa1100_gpio_chip(chip)->membase + R_GPDR;
unsigned long flags;
local_irq_save(flags);
writel_relaxed(readl_relaxed(gpdr) & ~BIT(offset), gpdr);
local_irq_restore(flags);
return 0;
}
static int sa1100_direction_output(struct gpio_chip *chip, unsigned offset, int value)
{
void __iomem *gpdr = sa1100_gpio_chip(chip)->membase + R_GPDR;
unsigned long flags;
local_irq_save(flags);
sa1100_gpio_set(chip, offset, value);
writel_relaxed(readl_relaxed(gpdr) | BIT(offset), gpdr);
local_irq_restore(flags);
return 0;
}
static int sa1100_to_irq(struct gpio_chip *chip, unsigned offset)
{
return sa1100_gpio_chip(chip)->irqbase + offset;
}
static struct sa1100_gpio_chip sa1100_gpio_chip = {
.chip = {
.label = "gpio",
.get_direction = sa1100_get_direction,
.direction_input = sa1100_direction_input,
.direction_output = sa1100_direction_output,
.set = sa1100_gpio_set,
.get = sa1100_gpio_get,
.to_irq = sa1100_to_irq,
.base = 0,
.ngpio = GPIO_MAX + 1,
},
.membase = (void *)&GPLR,
.irqbase = IRQ_GPIO0,
};
/*
* SA1100 GPIO edge detection for IRQs:
* IRQs are generated on Falling-Edge, Rising-Edge, or both.
* Use this instead of directly setting GRER/GFER.
*/
static void sa1100_update_edge_regs(struct sa1100_gpio_chip *sgc)
{
void *base = sgc->membase;
u32 grer, gfer;
grer = sgc->irqrising & sgc->irqmask;
gfer = sgc->irqfalling & sgc->irqmask;
writel_relaxed(grer, base + R_GRER);
writel_relaxed(gfer, base + R_GFER);
}
static int sa1100_gpio_type(struct irq_data *d, unsigned int type)
{
struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
unsigned int mask = BIT(d->hwirq);
if (type == IRQ_TYPE_PROBE) {
if ((sgc->irqrising | sgc->irqfalling) & mask)
return 0;
type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
}
if (type & IRQ_TYPE_EDGE_RISING)
sgc->irqrising |= mask;
else
sgc->irqrising &= ~mask;
if (type & IRQ_TYPE_EDGE_FALLING)
sgc->irqfalling |= mask;
else
sgc->irqfalling &= ~mask;
sa1100_update_edge_regs(sgc);
return 0;
}
/*
* GPIO IRQs must be acknowledged.
*/
static void sa1100_gpio_ack(struct irq_data *d)
{
struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
writel_relaxed(BIT(d->hwirq), sgc->membase + R_GEDR);
}
static void sa1100_gpio_mask(struct irq_data *d)
{
struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
unsigned int mask = BIT(d->hwirq);
sgc->irqmask &= ~mask;
sa1100_update_edge_regs(sgc);
}
static void sa1100_gpio_unmask(struct irq_data *d)
{
struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
unsigned int mask = BIT(d->hwirq);
sgc->irqmask |= mask;
sa1100_update_edge_regs(sgc);
}
static int sa1100_gpio_wake(struct irq_data *d, unsigned int on)
{
struct sa1100_gpio_chip *sgc = irq_data_get_irq_chip_data(d);
int ret = sa11x0_gpio_set_wake(d->hwirq, on);
if (!ret) {
if (on)
sgc->irqwake |= BIT(d->hwirq);
else
sgc->irqwake &= ~BIT(d->hwirq);
}
return ret;
}
/*
* This is for GPIO IRQs
*/
static struct irq_chip sa1100_gpio_irq_chip = {
.name = "GPIO",
.irq_ack = sa1100_gpio_ack,
.irq_mask = sa1100_gpio_mask,
.irq_unmask = sa1100_gpio_unmask,
.irq_set_type = sa1100_gpio_type,
.irq_set_wake = sa1100_gpio_wake,
};
static int sa1100_gpio_irqdomain_map(struct irq_domain *d,
unsigned int irq, irq_hw_number_t hwirq)
{
struct sa1100_gpio_chip *sgc = d->host_data;
irq_set_chip_data(irq, sgc);
irq_set_chip_and_handler(irq, &sa1100_gpio_irq_chip, handle_edge_irq);
irq_set_probe(irq);
return 0;
}
static const struct irq_domain_ops sa1100_gpio_irqdomain_ops = {
.map = sa1100_gpio_irqdomain_map,
.xlate = irq_domain_xlate_onetwocell,
};
static struct irq_domain *sa1100_gpio_irqdomain;
/*
* IRQ 0-11 (GPIO) handler. We enter here with the
* irq_controller_lock held, and IRQs disabled. Decode the IRQ
* and call the handler.
*/
static void sa1100_gpio_handler(struct irq_desc *desc)
{
struct sa1100_gpio_chip *sgc = irq_desc_get_handler_data(desc);
unsigned int irq, mask;
void __iomem *gedr = sgc->membase + R_GEDR;
mask = readl_relaxed(gedr);
do {
/*
* clear down all currently active IRQ sources.
* We will be processing them all.
*/
writel_relaxed(mask, gedr);
irq = sgc->irqbase;
do {
if (mask & 1)
generic_handle_irq(irq);
mask >>= 1;
irq++;
} while (mask);
mask = readl_relaxed(gedr);
} while (mask);
}
static int sa1100_gpio_suspend(void)
{
struct sa1100_gpio_chip *sgc = &sa1100_gpio_chip;
/*
* Set the appropriate edges for wakeup.
*/
writel_relaxed(sgc->irqwake & sgc->irqrising, sgc->membase + R_GRER);
writel_relaxed(sgc->irqwake & sgc->irqfalling, sgc->membase + R_GFER);
/*
* Clear any pending GPIO interrupts.
*/
writel_relaxed(readl_relaxed(sgc->membase + R_GEDR),
sgc->membase + R_GEDR);
return 0;
}
static void sa1100_gpio_resume(void)
{
sa1100_update_edge_regs(&sa1100_gpio_chip);
}
static struct syscore_ops sa1100_gpio_syscore_ops = {
.suspend = sa1100_gpio_suspend,
.resume = sa1100_gpio_resume,
};
static int __init sa1100_gpio_init_devicefs(void)
{
register_syscore_ops(&sa1100_gpio_syscore_ops);
return 0;
}
device_initcall(sa1100_gpio_init_devicefs);
static const int sa1100_gpio_irqs[] __initconst = {
/* Install handlers for GPIO 0-10 edge detect interrupts */
IRQ_GPIO0_SC,
IRQ_GPIO1_SC,
IRQ_GPIO2_SC,
IRQ_GPIO3_SC,
IRQ_GPIO4_SC,
IRQ_GPIO5_SC,
IRQ_GPIO6_SC,
IRQ_GPIO7_SC,
IRQ_GPIO8_SC,
IRQ_GPIO9_SC,
IRQ_GPIO10_SC,
/* Install handler for GPIO 11-27 edge detect interrupts */
IRQ_GPIO11_27,
};
void __init sa1100_init_gpio(void)
{
struct sa1100_gpio_chip *sgc = &sa1100_gpio_chip;
int i;
/* clear all GPIO edge detects */
writel_relaxed(0, sgc->membase + R_GFER);
writel_relaxed(0, sgc->membase + R_GRER);
writel_relaxed(-1, sgc->membase + R_GEDR);
gpiochip_add_data(&sa1100_gpio_chip.chip, NULL);
sa1100_gpio_irqdomain = irq_domain_add_simple(NULL,
28, IRQ_GPIO0,
&sa1100_gpio_irqdomain_ops, sgc);
for (i = 0; i < ARRAY_SIZE(sa1100_gpio_irqs); i++)
irq_set_chained_handler_and_data(sa1100_gpio_irqs[i],
sa1100_gpio_handler, sgc);
}