Staging
v0.8.0
v0.8.0
https://github.com/torvalds/linux
Tip revision: 30a7acd573899fd8b8ac39236eff6468b195ac7d authored by Linus Torvalds on 31 December 2017, 22:47:43 UTC
Linux 4.15-rc6
Linux 4.15-rc6
Tip revision: 30a7acd
gpio.c
/*
* arch/arm/plat-orion/gpio.c
*
* Marvell Orion SoC GPIO handling.
*
* 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.
*/
#define DEBUG
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/bitops.h>
#include <linux/io.h>
#include <linux/gpio.h>
#include <linux/leds.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <plat/orion-gpio.h>
/*
* GPIO unit register offsets.
*/
#define GPIO_OUT_OFF 0x0000
#define GPIO_IO_CONF_OFF 0x0004
#define GPIO_BLINK_EN_OFF 0x0008
#define GPIO_IN_POL_OFF 0x000c
#define GPIO_DATA_IN_OFF 0x0010
#define GPIO_EDGE_CAUSE_OFF 0x0014
#define GPIO_EDGE_MASK_OFF 0x0018
#define GPIO_LEVEL_MASK_OFF 0x001c
struct orion_gpio_chip {
struct gpio_chip chip;
spinlock_t lock;
void __iomem *base;
unsigned long valid_input;
unsigned long valid_output;
int mask_offset;
int secondary_irq_base;
struct irq_domain *domain;
};
static void __iomem *GPIO_OUT(struct orion_gpio_chip *ochip)
{
return ochip->base + GPIO_OUT_OFF;
}
static void __iomem *GPIO_IO_CONF(struct orion_gpio_chip *ochip)
{
return ochip->base + GPIO_IO_CONF_OFF;
}
static void __iomem *GPIO_BLINK_EN(struct orion_gpio_chip *ochip)
{
return ochip->base + GPIO_BLINK_EN_OFF;
}
static void __iomem *GPIO_IN_POL(struct orion_gpio_chip *ochip)
{
return ochip->base + GPIO_IN_POL_OFF;
}
static void __iomem *GPIO_DATA_IN(struct orion_gpio_chip *ochip)
{
return ochip->base + GPIO_DATA_IN_OFF;
}
static void __iomem *GPIO_EDGE_CAUSE(struct orion_gpio_chip *ochip)
{
return ochip->base + GPIO_EDGE_CAUSE_OFF;
}
static void __iomem *GPIO_EDGE_MASK(struct orion_gpio_chip *ochip)
{
return ochip->base + ochip->mask_offset + GPIO_EDGE_MASK_OFF;
}
static void __iomem *GPIO_LEVEL_MASK(struct orion_gpio_chip *ochip)
{
return ochip->base + ochip->mask_offset + GPIO_LEVEL_MASK_OFF;
}
static struct orion_gpio_chip orion_gpio_chips[2];
static int orion_gpio_chip_count;
static inline void
__set_direction(struct orion_gpio_chip *ochip, unsigned pin, int input)
{
u32 u;
u = readl(GPIO_IO_CONF(ochip));
if (input)
u |= 1 << pin;
else
u &= ~(1 << pin);
writel(u, GPIO_IO_CONF(ochip));
}
static void __set_level(struct orion_gpio_chip *ochip, unsigned pin, int high)
{
u32 u;
u = readl(GPIO_OUT(ochip));
if (high)
u |= 1 << pin;
else
u &= ~(1 << pin);
writel(u, GPIO_OUT(ochip));
}
static inline void
__set_blinking(struct orion_gpio_chip *ochip, unsigned pin, int blink)
{
u32 u;
u = readl(GPIO_BLINK_EN(ochip));
if (blink)
u |= 1 << pin;
else
u &= ~(1 << pin);
writel(u, GPIO_BLINK_EN(ochip));
}
static inline int
orion_gpio_is_valid(struct orion_gpio_chip *ochip, unsigned pin, int mode)
{
if (pin >= ochip->chip.ngpio)
goto err_out;
if ((mode & GPIO_INPUT_OK) && !test_bit(pin, &ochip->valid_input))
goto err_out;
if ((mode & GPIO_OUTPUT_OK) && !test_bit(pin, &ochip->valid_output))
goto err_out;
return 1;
err_out:
pr_debug("%s: invalid GPIO %d\n", __func__, pin);
return false;
}
/*
* GPIO primitives.
*/
static int orion_gpio_request(struct gpio_chip *chip, unsigned pin)
{
struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
if (orion_gpio_is_valid(ochip, pin, GPIO_INPUT_OK) ||
orion_gpio_is_valid(ochip, pin, GPIO_OUTPUT_OK))
return 0;
return -EINVAL;
}
static int orion_gpio_direction_input(struct gpio_chip *chip, unsigned pin)
{
struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
unsigned long flags;
if (!orion_gpio_is_valid(ochip, pin, GPIO_INPUT_OK))
return -EINVAL;
spin_lock_irqsave(&ochip->lock, flags);
__set_direction(ochip, pin, 1);
spin_unlock_irqrestore(&ochip->lock, flags);
return 0;
}
static int orion_gpio_get(struct gpio_chip *chip, unsigned pin)
{
struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
int val;
if (readl(GPIO_IO_CONF(ochip)) & (1 << pin)) {
val = readl(GPIO_DATA_IN(ochip)) ^ readl(GPIO_IN_POL(ochip));
} else {
val = readl(GPIO_OUT(ochip));
}
return (val >> pin) & 1;
}
static int
orion_gpio_direction_output(struct gpio_chip *chip, unsigned pin, int value)
{
struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
unsigned long flags;
if (!orion_gpio_is_valid(ochip, pin, GPIO_OUTPUT_OK))
return -EINVAL;
spin_lock_irqsave(&ochip->lock, flags);
__set_blinking(ochip, pin, 0);
__set_level(ochip, pin, value);
__set_direction(ochip, pin, 0);
spin_unlock_irqrestore(&ochip->lock, flags);
return 0;
}
static void orion_gpio_set(struct gpio_chip *chip, unsigned pin, int value)
{
struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
unsigned long flags;
spin_lock_irqsave(&ochip->lock, flags);
__set_level(ochip, pin, value);
spin_unlock_irqrestore(&ochip->lock, flags);
}
static int orion_gpio_to_irq(struct gpio_chip *chip, unsigned pin)
{
struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
return irq_create_mapping(ochip->domain,
ochip->secondary_irq_base + pin);
}
/*
* Orion-specific GPIO API extensions.
*/
static struct orion_gpio_chip *orion_gpio_chip_find(int pin)
{
int i;
for (i = 0; i < orion_gpio_chip_count; i++) {
struct orion_gpio_chip *ochip = orion_gpio_chips + i;
struct gpio_chip *chip = &ochip->chip;
if (pin >= chip->base && pin < chip->base + chip->ngpio)
return ochip;
}
return NULL;
}
void __init orion_gpio_set_unused(unsigned pin)
{
struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
if (ochip == NULL)
return;
pin -= ochip->chip.base;
/* Configure as output, drive low. */
__set_level(ochip, pin, 0);
__set_direction(ochip, pin, 0);
}
void __init orion_gpio_set_valid(unsigned pin, int mode)
{
struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
if (ochip == NULL)
return;
pin -= ochip->chip.base;
if (mode == 1)
mode = GPIO_INPUT_OK | GPIO_OUTPUT_OK;
if (mode & GPIO_INPUT_OK)
__set_bit(pin, &ochip->valid_input);
else
__clear_bit(pin, &ochip->valid_input);
if (mode & GPIO_OUTPUT_OK)
__set_bit(pin, &ochip->valid_output);
else
__clear_bit(pin, &ochip->valid_output);
}
void orion_gpio_set_blink(unsigned pin, int blink)
{
struct orion_gpio_chip *ochip = orion_gpio_chip_find(pin);
unsigned long flags;
if (ochip == NULL)
return;
spin_lock_irqsave(&ochip->lock, flags);
__set_level(ochip, pin & 31, 0);
__set_blinking(ochip, pin & 31, blink);
spin_unlock_irqrestore(&ochip->lock, flags);
}
EXPORT_SYMBOL(orion_gpio_set_blink);
#define ORION_BLINK_HALF_PERIOD 100 /* ms */
int orion_gpio_led_blink_set(struct gpio_desc *desc, int state,
unsigned long *delay_on, unsigned long *delay_off)
{
unsigned gpio = desc_to_gpio(desc);
if (delay_on && delay_off && !*delay_on && !*delay_off)
*delay_on = *delay_off = ORION_BLINK_HALF_PERIOD;
switch (state) {
case GPIO_LED_NO_BLINK_LOW:
case GPIO_LED_NO_BLINK_HIGH:
orion_gpio_set_blink(gpio, 0);
gpio_set_value(gpio, state);
break;
case GPIO_LED_BLINK:
orion_gpio_set_blink(gpio, 1);
}
return 0;
}
EXPORT_SYMBOL_GPL(orion_gpio_led_blink_set);
/*****************************************************************************
* Orion GPIO IRQ
*
* GPIO_IN_POL register controls whether GPIO_DATA_IN will hold the same
* value of the line or the opposite value.
*
* Level IRQ handlers: DATA_IN is used directly as cause register.
* Interrupt are masked by LEVEL_MASK registers.
* Edge IRQ handlers: Change in DATA_IN are latched in EDGE_CAUSE.
* Interrupt are masked by EDGE_MASK registers.
* Both-edge handlers: Similar to regular Edge handlers, but also swaps
* the polarity to catch the next line transaction.
* This is a race condition that might not perfectly
* work on some use cases.
*
* Every eight GPIO lines are grouped (OR'ed) before going up to main
* cause register.
*
* EDGE cause mask
* data-in /--------| |-----| |----\
* -----| |----- ---- to main cause reg
* X \----------------| |----/
* polarity LEVEL mask
*
****************************************************************************/
static int gpio_irq_set_type(struct irq_data *d, u32 type)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
struct irq_chip_type *ct = irq_data_get_chip_type(d);
struct orion_gpio_chip *ochip = gc->private;
int pin;
u32 u;
pin = d->hwirq - ochip->secondary_irq_base;
u = readl(GPIO_IO_CONF(ochip)) & (1 << pin);
if (!u) {
return -EINVAL;
}
type &= IRQ_TYPE_SENSE_MASK;
if (type == IRQ_TYPE_NONE)
return -EINVAL;
/* Check if we need to change chip and handler */
if (!(ct->type & type))
if (irq_setup_alt_chip(d, type))
return -EINVAL;
/*
* Configure interrupt polarity.
*/
if (type == IRQ_TYPE_EDGE_RISING || type == IRQ_TYPE_LEVEL_HIGH) {
u = readl(GPIO_IN_POL(ochip));
u &= ~(1 << pin);
writel(u, GPIO_IN_POL(ochip));
} else if (type == IRQ_TYPE_EDGE_FALLING || type == IRQ_TYPE_LEVEL_LOW) {
u = readl(GPIO_IN_POL(ochip));
u |= 1 << pin;
writel(u, GPIO_IN_POL(ochip));
} else if (type == IRQ_TYPE_EDGE_BOTH) {
u32 v;
v = readl(GPIO_IN_POL(ochip)) ^ readl(GPIO_DATA_IN(ochip));
/*
* set initial polarity based on current input level
*/
u = readl(GPIO_IN_POL(ochip));
if (v & (1 << pin))
u |= 1 << pin; /* falling */
else
u &= ~(1 << pin); /* rising */
writel(u, GPIO_IN_POL(ochip));
}
return 0;
}
static void gpio_irq_handler(struct irq_desc *desc)
{
struct orion_gpio_chip *ochip = irq_desc_get_handler_data(desc);
u32 cause, type;
int i;
if (ochip == NULL)
return;
cause = readl(GPIO_DATA_IN(ochip)) & readl(GPIO_LEVEL_MASK(ochip));
cause |= readl(GPIO_EDGE_CAUSE(ochip)) & readl(GPIO_EDGE_MASK(ochip));
for (i = 0; i < ochip->chip.ngpio; i++) {
int irq;
irq = ochip->secondary_irq_base + i;
if (!(cause & (1 << i)))
continue;
type = irq_get_trigger_type(irq);
if ((type & IRQ_TYPE_SENSE_MASK) == IRQ_TYPE_EDGE_BOTH) {
/* Swap polarity (race with GPIO line) */
u32 polarity;
polarity = readl(GPIO_IN_POL(ochip));
polarity ^= 1 << i;
writel(polarity, GPIO_IN_POL(ochip));
}
generic_handle_irq(irq);
}
}
#ifdef CONFIG_DEBUG_FS
#include <linux/seq_file.h>
static void orion_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
{
struct orion_gpio_chip *ochip = gpiochip_get_data(chip);
u32 out, io_conf, blink, in_pol, data_in, cause, edg_msk, lvl_msk;
int i;
out = readl_relaxed(GPIO_OUT(ochip));
io_conf = readl_relaxed(GPIO_IO_CONF(ochip));
blink = readl_relaxed(GPIO_BLINK_EN(ochip));
in_pol = readl_relaxed(GPIO_IN_POL(ochip));
data_in = readl_relaxed(GPIO_DATA_IN(ochip));
cause = readl_relaxed(GPIO_EDGE_CAUSE(ochip));
edg_msk = readl_relaxed(GPIO_EDGE_MASK(ochip));
lvl_msk = readl_relaxed(GPIO_LEVEL_MASK(ochip));
for (i = 0; i < chip->ngpio; i++) {
const char *label;
u32 msk;
bool is_out;
label = gpiochip_is_requested(chip, i);
if (!label)
continue;
msk = 1 << i;
is_out = !(io_conf & msk);
seq_printf(s, " gpio-%-3d (%-20.20s)", chip->base + i, label);
if (is_out) {
seq_printf(s, " out %s %s\n",
out & msk ? "hi" : "lo",
blink & msk ? "(blink )" : "");
continue;
}
seq_printf(s, " in %s (act %s) - IRQ",
(data_in ^ in_pol) & msk ? "hi" : "lo",
in_pol & msk ? "lo" : "hi");
if (!((edg_msk | lvl_msk) & msk)) {
seq_puts(s, " disabled\n");
continue;
}
if (edg_msk & msk)
seq_puts(s, " edge ");
if (lvl_msk & msk)
seq_puts(s, " level");
seq_printf(s, " (%s)\n", cause & msk ? "pending" : "clear ");
}
}
#else
#define orion_gpio_dbg_show NULL
#endif
static void orion_gpio_unmask_irq(struct irq_data *d)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
struct irq_chip_type *ct = irq_data_get_chip_type(d);
u32 reg_val;
u32 mask = d->mask;
irq_gc_lock(gc);
reg_val = irq_reg_readl(gc, ct->regs.mask);
reg_val |= mask;
irq_reg_writel(gc, reg_val, ct->regs.mask);
irq_gc_unlock(gc);
}
static void orion_gpio_mask_irq(struct irq_data *d)
{
struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
struct irq_chip_type *ct = irq_data_get_chip_type(d);
u32 mask = d->mask;
u32 reg_val;
irq_gc_lock(gc);
reg_val = irq_reg_readl(gc, ct->regs.mask);
reg_val &= ~mask;
irq_reg_writel(gc, reg_val, ct->regs.mask);
irq_gc_unlock(gc);
}
void __init orion_gpio_init(struct device_node *np,
int gpio_base, int ngpio,
void __iomem *base, int mask_offset,
int secondary_irq_base,
int irqs[4])
{
struct orion_gpio_chip *ochip;
struct irq_chip_generic *gc;
struct irq_chip_type *ct;
char gc_label[16];
int i;
if (orion_gpio_chip_count == ARRAY_SIZE(orion_gpio_chips))
return;
snprintf(gc_label, sizeof(gc_label), "orion_gpio%d",
orion_gpio_chip_count);
ochip = orion_gpio_chips + orion_gpio_chip_count;
ochip->chip.label = kstrdup(gc_label, GFP_KERNEL);
ochip->chip.request = orion_gpio_request;
ochip->chip.direction_input = orion_gpio_direction_input;
ochip->chip.get = orion_gpio_get;
ochip->chip.direction_output = orion_gpio_direction_output;
ochip->chip.set = orion_gpio_set;
ochip->chip.to_irq = orion_gpio_to_irq;
ochip->chip.base = gpio_base;
ochip->chip.ngpio = ngpio;
ochip->chip.can_sleep = 0;
#ifdef CONFIG_OF
ochip->chip.of_node = np;
#endif
ochip->chip.dbg_show = orion_gpio_dbg_show;
spin_lock_init(&ochip->lock);
ochip->base = (void __iomem *)base;
ochip->valid_input = 0;
ochip->valid_output = 0;
ochip->mask_offset = mask_offset;
ochip->secondary_irq_base = secondary_irq_base;
gpiochip_add_data(&ochip->chip, ochip);
/*
* Mask and clear GPIO interrupts.
*/
writel(0, GPIO_EDGE_CAUSE(ochip));
writel(0, GPIO_EDGE_MASK(ochip));
writel(0, GPIO_LEVEL_MASK(ochip));
/* Setup the interrupt handlers. Each chip can have up to 4
* interrupt handlers, with each handler dealing with 8 GPIO
* pins. */
for (i = 0; i < 4; i++) {
if (irqs[i]) {
irq_set_chained_handler_and_data(irqs[i],
gpio_irq_handler,
ochip);
}
}
gc = irq_alloc_generic_chip("orion_gpio_irq", 2,
secondary_irq_base,
ochip->base, handle_level_irq);
gc->private = ochip;
ct = gc->chip_types;
ct->regs.mask = ochip->mask_offset + GPIO_LEVEL_MASK_OFF;
ct->type = IRQ_TYPE_LEVEL_HIGH | IRQ_TYPE_LEVEL_LOW;
ct->chip.irq_mask = orion_gpio_mask_irq;
ct->chip.irq_unmask = orion_gpio_unmask_irq;
ct->chip.irq_set_type = gpio_irq_set_type;
ct->chip.name = ochip->chip.label;
ct++;
ct->regs.mask = ochip->mask_offset + GPIO_EDGE_MASK_OFF;
ct->regs.ack = GPIO_EDGE_CAUSE_OFF;
ct->type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
ct->chip.irq_ack = irq_gc_ack_clr_bit;
ct->chip.irq_mask = orion_gpio_mask_irq;
ct->chip.irq_unmask = orion_gpio_unmask_irq;
ct->chip.irq_set_type = gpio_irq_set_type;
ct->handler = handle_edge_irq;
ct->chip.name = ochip->chip.label;
irq_setup_generic_chip(gc, IRQ_MSK(ngpio), IRQ_GC_INIT_MASK_CACHE,
IRQ_NOREQUEST, IRQ_LEVEL | IRQ_NOPROBE);
/* Setup irq domain on top of the generic chip. */
ochip->domain = irq_domain_add_legacy(np,
ochip->chip.ngpio,
ochip->secondary_irq_base,
ochip->secondary_irq_base,
&irq_domain_simple_ops,
ochip);
if (!ochip->domain)
panic("%s: couldn't allocate irq domain (DT).\n",
ochip->chip.label);
orion_gpio_chip_count++;
}