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linux/drivers/gpio/gpio-mpc8xxx.c
Liu Gang 1aeef303b5 powerpc/gpio: Fix the wrong GPIO input data on MPC8572/MPC8536 
For MPC8572/MPC8536, the status of GPIOs defined as output
cannot be determined by reading GPDAT register, so the code
use shadow data register instead. But the code may give the
wrong status of GPIOs defined as input under some scenarios:

1. If some pins were configured as inputs and were asserted
high before booting the kernel, the shadow data has been
initialized with those pin values.
2. Some pins have been configured as output first and have
been set to the high value, then reconfigured as input.

The above cases will make the shadow data for those input
pins to be set to high. Then reading the pin status will
always return high even if the actual pin status is low.

The code should eliminate the effects of the shadow data to
the input pins, and the status of those pins should be
read directly from GPDAT.

Cc: stable@vger.kernel.org
Acked-by: Scott Wood <scottwood@freescale.com>
Acked-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Liu Gang <Gang.Liu@freescale.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2013-12-03 13:10:48 +01:00

394 lines
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/*
* GPIOs on MPC512x/8349/8572/8610 and compatible
*
* Copyright (C) 2008 Peter Korsgaard <jacmet@sunsite.dk>
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_gpio.h>
#include <linux/of_irq.h>
#include <linux/gpio.h>
#include <linux/slab.h>
#include <linux/irq.h>
#define MPC8XXX_GPIO_PINS 32
#define GPIO_DIR 0x00
#define GPIO_ODR 0x04
#define GPIO_DAT 0x08
#define GPIO_IER 0x0c
#define GPIO_IMR 0x10
#define GPIO_ICR 0x14
#define GPIO_ICR2 0x18
struct mpc8xxx_gpio_chip {
struct of_mm_gpio_chip mm_gc;
spinlock_t lock;
/*
* shadowed data register to be able to clear/set output pins in
* open drain mode safely
*/
u32 data;
struct irq_domain *irq;
const void *of_dev_id_data;
};
static inline u32 mpc8xxx_gpio2mask(unsigned int gpio)
{
return 1u << (MPC8XXX_GPIO_PINS - 1 - gpio);
}
static inline struct mpc8xxx_gpio_chip *
to_mpc8xxx_gpio_chip(struct of_mm_gpio_chip *mm)
{
return container_of(mm, struct mpc8xxx_gpio_chip, mm_gc);
}
static void mpc8xxx_gpio_save_regs(struct of_mm_gpio_chip *mm)
{
struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
mpc8xxx_gc->data = in_be32(mm->regs + GPIO_DAT);
}
/* Workaround GPIO 1 errata on MPC8572/MPC8536. The status of GPIOs
* defined as output cannot be determined by reading GPDAT register,
* so we use shadow data register instead. The status of input pins
* is determined by reading GPDAT register.
*/
static int mpc8572_gpio_get(struct gpio_chip *gc, unsigned int gpio)
{
u32 val;
struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
u32 out_mask, out_shadow;
out_mask = in_be32(mm->regs + GPIO_DIR);
val = in_be32(mm->regs + GPIO_DAT) & ~out_mask;
out_shadow = mpc8xxx_gc->data & out_mask;
return (val | out_shadow) & mpc8xxx_gpio2mask(gpio);
}
static int mpc8xxx_gpio_get(struct gpio_chip *gc, unsigned int gpio)
{
struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
return in_be32(mm->regs + GPIO_DAT) & mpc8xxx_gpio2mask(gpio);
}
static void mpc8xxx_gpio_set(struct gpio_chip *gc, unsigned int gpio, int val)
{
struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
unsigned long flags;
spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
if (val)
mpc8xxx_gc->data |= mpc8xxx_gpio2mask(gpio);
else
mpc8xxx_gc->data &= ~mpc8xxx_gpio2mask(gpio);
out_be32(mm->regs + GPIO_DAT, mpc8xxx_gc->data);
spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
}
static int mpc8xxx_gpio_dir_in(struct gpio_chip *gc, unsigned int gpio)
{
struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
unsigned long flags;
spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
clrbits32(mm->regs + GPIO_DIR, mpc8xxx_gpio2mask(gpio));
spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
return 0;
}
static int mpc8xxx_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
{
struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
unsigned long flags;
mpc8xxx_gpio_set(gc, gpio, val);
spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
setbits32(mm->regs + GPIO_DIR, mpc8xxx_gpio2mask(gpio));
spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
return 0;
}
static int mpc5121_gpio_dir_out(struct gpio_chip *gc, unsigned int gpio, int val)
{
/* GPIO 28..31 are input only on MPC5121 */
if (gpio >= 28)
return -EINVAL;
return mpc8xxx_gpio_dir_out(gc, gpio, val);
}
static int mpc8xxx_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
{
struct of_mm_gpio_chip *mm = to_of_mm_gpio_chip(gc);
struct mpc8xxx_gpio_chip *mpc8xxx_gc = to_mpc8xxx_gpio_chip(mm);
if (mpc8xxx_gc->irq && offset < MPC8XXX_GPIO_PINS)
return irq_create_mapping(mpc8xxx_gc->irq, offset);
else
return -ENXIO;
}
static void mpc8xxx_gpio_irq_cascade(unsigned int irq, struct irq_desc *desc)
{
struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_desc_get_handler_data(desc);
struct irq_chip *chip = irq_desc_get_chip(desc);
struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
unsigned int mask;
mask = in_be32(mm->regs + GPIO_IER) & in_be32(mm->regs + GPIO_IMR);
if (mask)
generic_handle_irq(irq_linear_revmap(mpc8xxx_gc->irq,
32 - ffs(mask)));
if (chip->irq_eoi)
chip->irq_eoi(&desc->irq_data);
}
static void mpc8xxx_irq_unmask(struct irq_data *d)
{
struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
unsigned long flags;
spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
setbits32(mm->regs + GPIO_IMR, mpc8xxx_gpio2mask(irqd_to_hwirq(d)));
spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
}
static void mpc8xxx_irq_mask(struct irq_data *d)
{
struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
unsigned long flags;
spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
clrbits32(mm->regs + GPIO_IMR, mpc8xxx_gpio2mask(irqd_to_hwirq(d)));
spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
}
static void mpc8xxx_irq_ack(struct irq_data *d)
{
struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
out_be32(mm->regs + GPIO_IER, mpc8xxx_gpio2mask(irqd_to_hwirq(d)));
}
static int mpc8xxx_irq_set_type(struct irq_data *d, unsigned int flow_type)
{
struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
unsigned long flags;
switch (flow_type) {
case IRQ_TYPE_EDGE_FALLING:
spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
setbits32(mm->regs + GPIO_ICR,
mpc8xxx_gpio2mask(irqd_to_hwirq(d)));
spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
break;
case IRQ_TYPE_EDGE_BOTH:
spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
clrbits32(mm->regs + GPIO_ICR,
mpc8xxx_gpio2mask(irqd_to_hwirq(d)));
spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
break;
default:
return -EINVAL;
}
return 0;
}
static int mpc512x_irq_set_type(struct irq_data *d, unsigned int flow_type)
{
struct mpc8xxx_gpio_chip *mpc8xxx_gc = irq_data_get_irq_chip_data(d);
struct of_mm_gpio_chip *mm = &mpc8xxx_gc->mm_gc;
unsigned long gpio = irqd_to_hwirq(d);
void __iomem *reg;
unsigned int shift;
unsigned long flags;
if (gpio < 16) {
reg = mm->regs + GPIO_ICR;
shift = (15 - gpio) * 2;
} else {
reg = mm->regs + GPIO_ICR2;
shift = (15 - (gpio % 16)) * 2;
}
switch (flow_type) {
case IRQ_TYPE_EDGE_FALLING:
case IRQ_TYPE_LEVEL_LOW:
spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
clrsetbits_be32(reg, 3 << shift, 2 << shift);
spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
break;
case IRQ_TYPE_EDGE_RISING:
case IRQ_TYPE_LEVEL_HIGH:
spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
clrsetbits_be32(reg, 3 << shift, 1 << shift);
spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
break;
case IRQ_TYPE_EDGE_BOTH:
spin_lock_irqsave(&mpc8xxx_gc->lock, flags);
clrbits32(reg, 3 << shift);
spin_unlock_irqrestore(&mpc8xxx_gc->lock, flags);
break;
default:
return -EINVAL;
}
return 0;
}
static struct irq_chip mpc8xxx_irq_chip = {
.name = "mpc8xxx-gpio",
.irq_unmask = mpc8xxx_irq_unmask,
.irq_mask = mpc8xxx_irq_mask,
.irq_ack = mpc8xxx_irq_ack,
.irq_set_type = mpc8xxx_irq_set_type,
};
static int mpc8xxx_gpio_irq_map(struct irq_domain *h, unsigned int irq,
irq_hw_number_t hwirq)
{
struct mpc8xxx_gpio_chip *mpc8xxx_gc = h->host_data;
if (mpc8xxx_gc->of_dev_id_data)
mpc8xxx_irq_chip.irq_set_type = mpc8xxx_gc->of_dev_id_data;
irq_set_chip_data(irq, h->host_data);
irq_set_chip_and_handler(irq, &mpc8xxx_irq_chip, handle_level_irq);
return 0;
}
static struct irq_domain_ops mpc8xxx_gpio_irq_ops = {
.map = mpc8xxx_gpio_irq_map,
.xlate = irq_domain_xlate_twocell,
};
static struct of_device_id mpc8xxx_gpio_ids[] __initdata = {
{ .compatible = "fsl,mpc8349-gpio", },
{ .compatible = "fsl,mpc8572-gpio", },
{ .compatible = "fsl,mpc8610-gpio", },
{ .compatible = "fsl,mpc5121-gpio", .data = mpc512x_irq_set_type, },
{ .compatible = "fsl,pq3-gpio", },
{ .compatible = "fsl,qoriq-gpio", },
{}
};
static void __init mpc8xxx_add_controller(struct device_node *np)
{
struct mpc8xxx_gpio_chip *mpc8xxx_gc;
struct of_mm_gpio_chip *mm_gc;
struct gpio_chip *gc;
const struct of_device_id *id;
unsigned hwirq;
int ret;
mpc8xxx_gc = kzalloc(sizeof(*mpc8xxx_gc), GFP_KERNEL);
if (!mpc8xxx_gc) {
ret = -ENOMEM;
goto err;
}
spin_lock_init(&mpc8xxx_gc->lock);
mm_gc = &mpc8xxx_gc->mm_gc;
gc = &mm_gc->gc;
mm_gc->save_regs = mpc8xxx_gpio_save_regs;
gc->ngpio = MPC8XXX_GPIO_PINS;
gc->direction_input = mpc8xxx_gpio_dir_in;
gc->direction_output = of_device_is_compatible(np, "fsl,mpc5121-gpio") ?
mpc5121_gpio_dir_out : mpc8xxx_gpio_dir_out;
gc->get = of_device_is_compatible(np, "fsl,mpc8572-gpio") ?
mpc8572_gpio_get : mpc8xxx_gpio_get;
gc->set = mpc8xxx_gpio_set;
gc->to_irq = mpc8xxx_gpio_to_irq;
ret = of_mm_gpiochip_add(np, mm_gc);
if (ret)
goto err;
hwirq = irq_of_parse_and_map(np, 0);
if (hwirq == NO_IRQ)
goto skip_irq;
mpc8xxx_gc->irq = irq_domain_add_linear(np, MPC8XXX_GPIO_PINS,
&mpc8xxx_gpio_irq_ops, mpc8xxx_gc);
if (!mpc8xxx_gc->irq)
goto skip_irq;
id = of_match_node(mpc8xxx_gpio_ids, np);
if (id)
mpc8xxx_gc->of_dev_id_data = id->data;
/* ack and mask all irqs */
out_be32(mm_gc->regs + GPIO_IER, 0xffffffff);
out_be32(mm_gc->regs + GPIO_IMR, 0);
irq_set_handler_data(hwirq, mpc8xxx_gc);
irq_set_chained_handler(hwirq, mpc8xxx_gpio_irq_cascade);
skip_irq:
return;
err:
pr_err("%s: registration failed with status %d\n",
np->full_name, ret);
kfree(mpc8xxx_gc);
return;
}
static int __init mpc8xxx_add_gpiochips(void)
{
struct device_node *np;
for_each_matching_node(np, mpc8xxx_gpio_ids)
mpc8xxx_add_controller(np);
return 0;
}
arch_initcall(mpc8xxx_add_gpiochips);
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