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linux_dsm_epyc7002/drivers/pinctrl/bcm/pinctrl-bcm2835.c
Jonathan Bell 714b1dd8f7 pinctrl: bcm2835: Clear the event latch register when disabling interrupts 
It's possible to hit a race condition if interrupts are generated on a GPIO
pin when the IRQ line in question is being disabled.

If the interrupt is freed, bcm2835_gpio_irq_disable() is called which
disables the event generation sources (edge, level). If an event occurred
between the last disabling of hard IRQs and the write to the event
source registers, a bit would be set in the GPIO event detect register
(GPEDSn) which goes unacknowledged by bcm2835_gpio_irq_handler()
so Linux complains loudly.

There is no per-GPIO mask register, so when disabling GPIO interrupts
write 1 to the relevant bit in GPEDSn to clear out any stale events.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.org>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-07-20 11:01:52 +02:00

1083 lines
28 KiB
C
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/*
* Driver for Broadcom BCM2835 GPIO unit (pinctrl + GPIO)
*
* Copyright (C) 2012 Chris Boot, Simon Arlott, Stephen Warren
*
* This driver is inspired by:
* pinctrl-nomadik.c, please see original file for copyright information
* pinctrl-tegra.c, please see original file for copyright information
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <linux/bitmap.h>
#include <linux/bug.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/gpio.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/irq.h>
#include <linux/irqdesc.h>
#include <linux/irqdomain.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of.h>
#include <linux/of_irq.h>
#include <linux/pinctrl/consumer.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinconf.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/platform_device.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/types.h>
#define MODULE_NAME "pinctrl-bcm2835"
#define BCM2835_NUM_GPIOS 54
#define BCM2835_NUM_BANKS 2
#define BCM2835_PIN_BITMAP_SZ \
DIV_ROUND_UP(BCM2835_NUM_GPIOS, sizeof(unsigned long) * 8)
/* GPIO register offsets */
#define GPFSEL0 0x0 /* Function Select */
#define GPSET0 0x1c /* Pin Output Set */
#define GPCLR0 0x28 /* Pin Output Clear */
#define GPLEV0 0x34 /* Pin Level */
#define GPEDS0 0x40 /* Pin Event Detect Status */
#define GPREN0 0x4c /* Pin Rising Edge Detect Enable */
#define GPFEN0 0x58 /* Pin Falling Edge Detect Enable */
#define GPHEN0 0x64 /* Pin High Detect Enable */
#define GPLEN0 0x70 /* Pin Low Detect Enable */
#define GPAREN0 0x7c /* Pin Async Rising Edge Detect */
#define GPAFEN0 0x88 /* Pin Async Falling Edge Detect */
#define GPPUD 0x94 /* Pin Pull-up/down Enable */
#define GPPUDCLK0 0x98 /* Pin Pull-up/down Enable Clock */
#define FSEL_REG(p) (GPFSEL0 + (((p) / 10) * 4))
#define FSEL_SHIFT(p) (((p) % 10) * 3)
#define GPIO_REG_OFFSET(p) ((p) / 32)
#define GPIO_REG_SHIFT(p) ((p) % 32)
enum bcm2835_pinconf_param {
/* argument: bcm2835_pinconf_pull */
BCM2835_PINCONF_PARAM_PULL,
};
enum bcm2835_pinconf_pull {
BCM2835_PINCONFIG_PULL_NONE,
BCM2835_PINCONFIG_PULL_DOWN,
BCM2835_PINCONFIG_PULL_UP,
};
#define BCM2835_PINCONF_PACK(_param_, _arg_) ((_param_) << 16 | (_arg_))
#define BCM2835_PINCONF_UNPACK_PARAM(_conf_) ((_conf_) >> 16)
#define BCM2835_PINCONF_UNPACK_ARG(_conf_) ((_conf_) & 0xffff)
struct bcm2835_gpio_irqdata {
struct bcm2835_pinctrl *pc;
int bank;
};
struct bcm2835_pinctrl {
struct device *dev;
void __iomem *base;
int irq[BCM2835_NUM_BANKS];
/* note: locking assumes each bank will have its own unsigned long */
unsigned long enabled_irq_map[BCM2835_NUM_BANKS];
unsigned int irq_type[BCM2835_NUM_GPIOS];
struct pinctrl_dev *pctl_dev;
struct irq_domain *irq_domain;
struct gpio_chip gpio_chip;
struct pinctrl_gpio_range gpio_range;
struct bcm2835_gpio_irqdata irq_data[BCM2835_NUM_BANKS];
spinlock_t irq_lock[BCM2835_NUM_BANKS];
};
static struct lock_class_key gpio_lock_class;
/* pins are just named GPIO0..GPIO53 */
#define BCM2835_GPIO_PIN(a) PINCTRL_PIN(a, "gpio" #a)
static struct pinctrl_pin_desc bcm2835_gpio_pins[] = {
BCM2835_GPIO_PIN(0),
BCM2835_GPIO_PIN(1),
BCM2835_GPIO_PIN(2),
BCM2835_GPIO_PIN(3),
BCM2835_GPIO_PIN(4),
BCM2835_GPIO_PIN(5),
BCM2835_GPIO_PIN(6),
BCM2835_GPIO_PIN(7),
BCM2835_GPIO_PIN(8),
BCM2835_GPIO_PIN(9),
BCM2835_GPIO_PIN(10),
BCM2835_GPIO_PIN(11),
BCM2835_GPIO_PIN(12),
BCM2835_GPIO_PIN(13),
BCM2835_GPIO_PIN(14),
BCM2835_GPIO_PIN(15),
BCM2835_GPIO_PIN(16),
BCM2835_GPIO_PIN(17),
BCM2835_GPIO_PIN(18),
BCM2835_GPIO_PIN(19),
BCM2835_GPIO_PIN(20),
BCM2835_GPIO_PIN(21),
BCM2835_GPIO_PIN(22),
BCM2835_GPIO_PIN(23),
BCM2835_GPIO_PIN(24),
BCM2835_GPIO_PIN(25),
BCM2835_GPIO_PIN(26),
BCM2835_GPIO_PIN(27),
BCM2835_GPIO_PIN(28),
BCM2835_GPIO_PIN(29),
BCM2835_GPIO_PIN(30),
BCM2835_GPIO_PIN(31),
BCM2835_GPIO_PIN(32),
BCM2835_GPIO_PIN(33),
BCM2835_GPIO_PIN(34),
BCM2835_GPIO_PIN(35),
BCM2835_GPIO_PIN(36),
BCM2835_GPIO_PIN(37),
BCM2835_GPIO_PIN(38),
BCM2835_GPIO_PIN(39),
BCM2835_GPIO_PIN(40),
BCM2835_GPIO_PIN(41),
BCM2835_GPIO_PIN(42),
BCM2835_GPIO_PIN(43),
BCM2835_GPIO_PIN(44),
BCM2835_GPIO_PIN(45),
BCM2835_GPIO_PIN(46),
BCM2835_GPIO_PIN(47),
BCM2835_GPIO_PIN(48),
BCM2835_GPIO_PIN(49),
BCM2835_GPIO_PIN(50),
BCM2835_GPIO_PIN(51),
BCM2835_GPIO_PIN(52),
BCM2835_GPIO_PIN(53),
};
/* one pin per group */
static const char * const bcm2835_gpio_groups[] = {
"gpio0",
"gpio1",
"gpio2",
"gpio3",
"gpio4",
"gpio5",
"gpio6",
"gpio7",
"gpio8",
"gpio9",
"gpio10",
"gpio11",
"gpio12",
"gpio13",
"gpio14",
"gpio15",
"gpio16",
"gpio17",
"gpio18",
"gpio19",
"gpio20",
"gpio21",
"gpio22",
"gpio23",
"gpio24",
"gpio25",
"gpio26",
"gpio27",
"gpio28",
"gpio29",
"gpio30",
"gpio31",
"gpio32",
"gpio33",
"gpio34",
"gpio35",
"gpio36",
"gpio37",
"gpio38",
"gpio39",
"gpio40",
"gpio41",
"gpio42",
"gpio43",
"gpio44",
"gpio45",
"gpio46",
"gpio47",
"gpio48",
"gpio49",
"gpio50",
"gpio51",
"gpio52",
"gpio53",
};
enum bcm2835_fsel {
BCM2835_FSEL_GPIO_IN = 0,
BCM2835_FSEL_GPIO_OUT = 1,
BCM2835_FSEL_ALT0 = 4,
BCM2835_FSEL_ALT1 = 5,
BCM2835_FSEL_ALT2 = 6,
BCM2835_FSEL_ALT3 = 7,
BCM2835_FSEL_ALT4 = 3,
BCM2835_FSEL_ALT5 = 2,
BCM2835_FSEL_COUNT = 8,
BCM2835_FSEL_MASK = 0x7,
};
static const char * const bcm2835_functions[BCM2835_FSEL_COUNT] = {
[BCM2835_FSEL_GPIO_IN] = "gpio_in",
[BCM2835_FSEL_GPIO_OUT] = "gpio_out",
[BCM2835_FSEL_ALT0] = "alt0",
[BCM2835_FSEL_ALT1] = "alt1",
[BCM2835_FSEL_ALT2] = "alt2",
[BCM2835_FSEL_ALT3] = "alt3",
[BCM2835_FSEL_ALT4] = "alt4",
[BCM2835_FSEL_ALT5] = "alt5",
};
static const char * const irq_type_names[] = {
[IRQ_TYPE_NONE] = "none",
[IRQ_TYPE_EDGE_RISING] = "edge-rising",
[IRQ_TYPE_EDGE_FALLING] = "edge-falling",
[IRQ_TYPE_EDGE_BOTH] = "edge-both",
[IRQ_TYPE_LEVEL_HIGH] = "level-high",
[IRQ_TYPE_LEVEL_LOW] = "level-low",
};
static inline u32 bcm2835_gpio_rd(struct bcm2835_pinctrl *pc, unsigned reg)
{
return readl(pc->base + reg);
}
static inline void bcm2835_gpio_wr(struct bcm2835_pinctrl *pc, unsigned reg,
u32 val)
{
writel(val, pc->base + reg);
}
static inline int bcm2835_gpio_get_bit(struct bcm2835_pinctrl *pc, unsigned reg,
unsigned bit)
{
reg += GPIO_REG_OFFSET(bit) * 4;
return (bcm2835_gpio_rd(pc, reg) >> GPIO_REG_SHIFT(bit)) & 1;
}
/* note NOT a read/modify/write cycle */
static inline void bcm2835_gpio_set_bit(struct bcm2835_pinctrl *pc,
unsigned reg, unsigned bit)
{
reg += GPIO_REG_OFFSET(bit) * 4;
bcm2835_gpio_wr(pc, reg, BIT(GPIO_REG_SHIFT(bit)));
}
static inline enum bcm2835_fsel bcm2835_pinctrl_fsel_get(
struct bcm2835_pinctrl *pc, unsigned pin)
{
u32 val = bcm2835_gpio_rd(pc, FSEL_REG(pin));
enum bcm2835_fsel status = (val >> FSEL_SHIFT(pin)) & BCM2835_FSEL_MASK;
dev_dbg(pc->dev, "get %08x (%u => %s)\n", val, pin,
bcm2835_functions[status]);
return status;
}
static inline void bcm2835_pinctrl_fsel_set(
struct bcm2835_pinctrl *pc, unsigned pin,
enum bcm2835_fsel fsel)
{
u32 val = bcm2835_gpio_rd(pc, FSEL_REG(pin));
enum bcm2835_fsel cur = (val >> FSEL_SHIFT(pin)) & BCM2835_FSEL_MASK;
dev_dbg(pc->dev, "read %08x (%u => %s)\n", val, pin,
bcm2835_functions[cur]);
if (cur == fsel)
return;
if (cur != BCM2835_FSEL_GPIO_IN && fsel != BCM2835_FSEL_GPIO_IN) {
/* always transition through GPIO_IN */
val &= ~(BCM2835_FSEL_MASK << FSEL_SHIFT(pin));
val |= BCM2835_FSEL_GPIO_IN << FSEL_SHIFT(pin);
dev_dbg(pc->dev, "trans %08x (%u <= %s)\n", val, pin,
bcm2835_functions[BCM2835_FSEL_GPIO_IN]);
bcm2835_gpio_wr(pc, FSEL_REG(pin), val);
}
val &= ~(BCM2835_FSEL_MASK << FSEL_SHIFT(pin));
val |= fsel << FSEL_SHIFT(pin);
dev_dbg(pc->dev, "write %08x (%u <= %s)\n", val, pin,
bcm2835_functions[fsel]);
bcm2835_gpio_wr(pc, FSEL_REG(pin), val);
}
static int bcm2835_gpio_request(struct gpio_chip *chip, unsigned offset)
{
return pinctrl_request_gpio(chip->base + offset);
}
static void bcm2835_gpio_free(struct gpio_chip *chip, unsigned offset)
{
pinctrl_free_gpio(chip->base + offset);
}
static int bcm2835_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
return pinctrl_gpio_direction_input(chip->base + offset);
}
static int bcm2835_gpio_get(struct gpio_chip *chip, unsigned offset)
{
struct bcm2835_pinctrl *pc = dev_get_drvdata(chip->dev);
return bcm2835_gpio_get_bit(pc, GPLEV0, offset);
}
static int bcm2835_gpio_direction_output(struct gpio_chip *chip,
unsigned offset, int value)
{
return pinctrl_gpio_direction_output(chip->base + offset);
}
static void bcm2835_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct bcm2835_pinctrl *pc = dev_get_drvdata(chip->dev);
bcm2835_gpio_set_bit(pc, value ? GPSET0 : GPCLR0, offset);
}
static int bcm2835_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
{
struct bcm2835_pinctrl *pc = dev_get_drvdata(chip->dev);
return irq_linear_revmap(pc->irq_domain, offset);
}
static struct gpio_chip bcm2835_gpio_chip = {
.label = MODULE_NAME,
.owner = THIS_MODULE,
.request = bcm2835_gpio_request,
.free = bcm2835_gpio_free,
.direction_input = bcm2835_gpio_direction_input,
.direction_output = bcm2835_gpio_direction_output,
.get = bcm2835_gpio_get,
.set = bcm2835_gpio_set,
.to_irq = bcm2835_gpio_to_irq,
.base = -1,
.ngpio = BCM2835_NUM_GPIOS,
.can_sleep = false,
};
static irqreturn_t bcm2835_gpio_irq_handler(int irq, void *dev_id)
{
struct bcm2835_gpio_irqdata *irqdata = dev_id;
struct bcm2835_pinctrl *pc = irqdata->pc;
int bank = irqdata->bank;
unsigned long events;
unsigned offset;
unsigned gpio;
unsigned int type;
events = bcm2835_gpio_rd(pc, GPEDS0 + bank * 4);
events &= pc->enabled_irq_map[bank];
for_each_set_bit(offset, &events, 32) {
gpio = (32 * bank) + offset;
type = pc->irq_type[gpio];
generic_handle_irq(irq_linear_revmap(pc->irq_domain, gpio));
}
return events ? IRQ_HANDLED : IRQ_NONE;
}
static inline void __bcm2835_gpio_irq_config(struct bcm2835_pinctrl *pc,
unsigned reg, unsigned offset, bool enable)
{
u32 value;
reg += GPIO_REG_OFFSET(offset) * 4;
value = bcm2835_gpio_rd(pc, reg);
if (enable)
value |= BIT(GPIO_REG_SHIFT(offset));
else
value &= ~(BIT(GPIO_REG_SHIFT(offset)));
bcm2835_gpio_wr(pc, reg, value);
}
/* fast path for IRQ handler */
static void bcm2835_gpio_irq_config(struct bcm2835_pinctrl *pc,
unsigned offset, bool enable)
{
switch (pc->irq_type[offset]) {
case IRQ_TYPE_EDGE_RISING:
__bcm2835_gpio_irq_config(pc, GPREN0, offset, enable);
break;
case IRQ_TYPE_EDGE_FALLING:
__bcm2835_gpio_irq_config(pc, GPFEN0, offset, enable);
break;
case IRQ_TYPE_EDGE_BOTH:
__bcm2835_gpio_irq_config(pc, GPREN0, offset, enable);
__bcm2835_gpio_irq_config(pc, GPFEN0, offset, enable);
break;
case IRQ_TYPE_LEVEL_HIGH:
__bcm2835_gpio_irq_config(pc, GPHEN0, offset, enable);
break;
case IRQ_TYPE_LEVEL_LOW:
__bcm2835_gpio_irq_config(pc, GPLEN0, offset, enable);
break;
}
}
static void bcm2835_gpio_irq_enable(struct irq_data *data)
{
struct bcm2835_pinctrl *pc = irq_data_get_irq_chip_data(data);
unsigned gpio = irqd_to_hwirq(data);
unsigned offset = GPIO_REG_SHIFT(gpio);
unsigned bank = GPIO_REG_OFFSET(gpio);
unsigned long flags;
spin_lock_irqsave(&pc->irq_lock[bank], flags);
set_bit(offset, &pc->enabled_irq_map[bank]);
bcm2835_gpio_irq_config(pc, gpio, true);
spin_unlock_irqrestore(&pc->irq_lock[bank], flags);
}
static void bcm2835_gpio_irq_disable(struct irq_data *data)
{
struct bcm2835_pinctrl *pc = irq_data_get_irq_chip_data(data);
unsigned gpio = irqd_to_hwirq(data);
unsigned offset = GPIO_REG_SHIFT(gpio);
unsigned bank = GPIO_REG_OFFSET(gpio);
unsigned long flags;
spin_lock_irqsave(&pc->irq_lock[bank], flags);
bcm2835_gpio_irq_config(pc, gpio, false);
/* Clear events that were latched prior to clearing event sources */
bcm2835_gpio_set_bit(pc, GPEDS0, gpio);
clear_bit(offset, &pc->enabled_irq_map[bank]);
spin_unlock_irqrestore(&pc->irq_lock[bank], flags);
}
static int __bcm2835_gpio_irq_set_type_disabled(struct bcm2835_pinctrl *pc,
unsigned offset, unsigned int type)
{
switch (type) {
case IRQ_TYPE_NONE:
case IRQ_TYPE_EDGE_RISING:
case IRQ_TYPE_EDGE_FALLING:
case IRQ_TYPE_EDGE_BOTH:
case IRQ_TYPE_LEVEL_HIGH:
case IRQ_TYPE_LEVEL_LOW:
pc->irq_type[offset] = type;
break;
default:
return -EINVAL;
}
return 0;
}
/* slower path for reconfiguring IRQ type */
static int __bcm2835_gpio_irq_set_type_enabled(struct bcm2835_pinctrl *pc,
unsigned offset, unsigned int type)
{
switch (type) {
case IRQ_TYPE_NONE:
if (pc->irq_type[offset] != type) {
bcm2835_gpio_irq_config(pc, offset, false);
pc->irq_type[offset] = type;
}
break;
case IRQ_TYPE_EDGE_RISING:
if (pc->irq_type[offset] == IRQ_TYPE_EDGE_BOTH) {
/* RISING already enabled, disable FALLING */
pc->irq_type[offset] = IRQ_TYPE_EDGE_FALLING;
bcm2835_gpio_irq_config(pc, offset, false);
pc->irq_type[offset] = type;
} else if (pc->irq_type[offset] != type) {
bcm2835_gpio_irq_config(pc, offset, false);
pc->irq_type[offset] = type;
bcm2835_gpio_irq_config(pc, offset, true);
}
break;
case IRQ_TYPE_EDGE_FALLING:
if (pc->irq_type[offset] == IRQ_TYPE_EDGE_BOTH) {
/* FALLING already enabled, disable RISING */
pc->irq_type[offset] = IRQ_TYPE_EDGE_RISING;
bcm2835_gpio_irq_config(pc, offset, false);
pc->irq_type[offset] = type;
} else if (pc->irq_type[offset] != type) {
bcm2835_gpio_irq_config(pc, offset, false);
pc->irq_type[offset] = type;
bcm2835_gpio_irq_config(pc, offset, true);
}
break;
case IRQ_TYPE_EDGE_BOTH:
if (pc->irq_type[offset] == IRQ_TYPE_EDGE_RISING) {
/* RISING already enabled, enable FALLING too */
pc->irq_type[offset] = IRQ_TYPE_EDGE_FALLING;
bcm2835_gpio_irq_config(pc, offset, true);
pc->irq_type[offset] = type;
} else if (pc->irq_type[offset] == IRQ_TYPE_EDGE_FALLING) {
/* FALLING already enabled, enable RISING too */
pc->irq_type[offset] = IRQ_TYPE_EDGE_RISING;
bcm2835_gpio_irq_config(pc, offset, true);
pc->irq_type[offset] = type;
} else if (pc->irq_type[offset] != type) {
bcm2835_gpio_irq_config(pc, offset, false);
pc->irq_type[offset] = type;
bcm2835_gpio_irq_config(pc, offset, true);
}
break;
case IRQ_TYPE_LEVEL_HIGH:
case IRQ_TYPE_LEVEL_LOW:
if (pc->irq_type[offset] != type) {
bcm2835_gpio_irq_config(pc, offset, false);
pc->irq_type[offset] = type;
bcm2835_gpio_irq_config(pc, offset, true);
}
break;
default:
return -EINVAL;
}
return 0;
}
static int bcm2835_gpio_irq_set_type(struct irq_data *data, unsigned int type)
{
struct bcm2835_pinctrl *pc = irq_data_get_irq_chip_data(data);
unsigned gpio = irqd_to_hwirq(data);
unsigned offset = GPIO_REG_SHIFT(gpio);
unsigned bank = GPIO_REG_OFFSET(gpio);
unsigned long flags;
int ret;
spin_lock_irqsave(&pc->irq_lock[bank], flags);
if (test_bit(offset, &pc->enabled_irq_map[bank]))
ret = __bcm2835_gpio_irq_set_type_enabled(pc, gpio, type);
else
ret = __bcm2835_gpio_irq_set_type_disabled(pc, gpio, type);
if (type & IRQ_TYPE_EDGE_BOTH)
__irq_set_handler_locked(data->irq, handle_edge_irq);
else
__irq_set_handler_locked(data->irq, handle_level_irq);
spin_unlock_irqrestore(&pc->irq_lock[bank], flags);
return ret;
}
static void bcm2835_gpio_irq_ack(struct irq_data *data)
{
struct bcm2835_pinctrl *pc = irq_data_get_irq_chip_data(data);
unsigned gpio = irqd_to_hwirq(data);
bcm2835_gpio_set_bit(pc, GPEDS0, gpio);
}
static struct irq_chip bcm2835_gpio_irq_chip = {
.name = MODULE_NAME,
.irq_enable = bcm2835_gpio_irq_enable,
.irq_disable = bcm2835_gpio_irq_disable,
.irq_set_type = bcm2835_gpio_irq_set_type,
.irq_ack = bcm2835_gpio_irq_ack,
.irq_mask = bcm2835_gpio_irq_disable,
.irq_unmask = bcm2835_gpio_irq_enable,
};
static int bcm2835_pctl_get_groups_count(struct pinctrl_dev *pctldev)
{
return ARRAY_SIZE(bcm2835_gpio_groups);
}
static const char *bcm2835_pctl_get_group_name(struct pinctrl_dev *pctldev,
unsigned selector)
{
return bcm2835_gpio_groups[selector];
}
static int bcm2835_pctl_get_group_pins(struct pinctrl_dev *pctldev,
unsigned selector,
const unsigned **pins,
unsigned *num_pins)
{
*pins = &bcm2835_gpio_pins[selector].number;
*num_pins = 1;
return 0;
}
static void bcm2835_pctl_pin_dbg_show(struct pinctrl_dev *pctldev,
struct seq_file *s,
unsigned offset)
{
struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
enum bcm2835_fsel fsel = bcm2835_pinctrl_fsel_get(pc, offset);
const char *fname = bcm2835_functions[fsel];
int value = bcm2835_gpio_get_bit(pc, GPLEV0, offset);
int irq = irq_find_mapping(pc->irq_domain, offset);
seq_printf(s, "function %s in %s; irq %d (%s)",
fname, value ? "hi" : "lo",
irq, irq_type_names[pc->irq_type[offset]]);
}
static void bcm2835_pctl_dt_free_map(struct pinctrl_dev *pctldev,
struct pinctrl_map *maps, unsigned num_maps)
{
int i;
for (i = 0; i < num_maps; i++)
if (maps[i].type == PIN_MAP_TYPE_CONFIGS_PIN)
kfree(maps[i].data.configs.configs);
kfree(maps);
}
static int bcm2835_pctl_dt_node_to_map_func(struct bcm2835_pinctrl *pc,
struct device_node *np, u32 pin, u32 fnum,
struct pinctrl_map **maps)
{
struct pinctrl_map *map = *maps;
if (fnum >= ARRAY_SIZE(bcm2835_functions)) {
dev_err(pc->dev, "%s: invalid brcm,function %d\n",
of_node_full_name(np), fnum);
return -EINVAL;
}
map->type = PIN_MAP_TYPE_MUX_GROUP;
map->data.mux.group = bcm2835_gpio_groups[pin];
map->data.mux.function = bcm2835_functions[fnum];
(*maps)++;
return 0;
}
static int bcm2835_pctl_dt_node_to_map_pull(struct bcm2835_pinctrl *pc,
struct device_node *np, u32 pin, u32 pull,
struct pinctrl_map **maps)
{
struct pinctrl_map *map = *maps;
unsigned long *configs;
if (pull > 2) {
dev_err(pc->dev, "%s: invalid brcm,pull %d\n",
of_node_full_name(np), pull);
return -EINVAL;
}
configs = kzalloc(sizeof(*configs), GFP_KERNEL);
if (!configs)
return -ENOMEM;
configs[0] = BCM2835_PINCONF_PACK(BCM2835_PINCONF_PARAM_PULL, pull);
map->type = PIN_MAP_TYPE_CONFIGS_PIN;
map->data.configs.group_or_pin = bcm2835_gpio_pins[pin].name;
map->data.configs.configs = configs;
map->data.configs.num_configs = 1;
(*maps)++;
return 0;
}
static int bcm2835_pctl_dt_node_to_map(struct pinctrl_dev *pctldev,
struct device_node *np,
struct pinctrl_map **map, unsigned *num_maps)
{
struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
struct property *pins, *funcs, *pulls;
int num_pins, num_funcs, num_pulls, maps_per_pin;
struct pinctrl_map *maps, *cur_map;
int i, err;
u32 pin, func, pull;
pins = of_find_property(np, "brcm,pins", NULL);
if (!pins) {
dev_err(pc->dev, "%s: missing brcm,pins property\n",
of_node_full_name(np));
return -EINVAL;
}
funcs = of_find_property(np, "brcm,function", NULL);
pulls = of_find_property(np, "brcm,pull", NULL);
if (!funcs && !pulls) {
dev_err(pc->dev,
"%s: neither brcm,function nor brcm,pull specified\n",
of_node_full_name(np));
return -EINVAL;
}
num_pins = pins->length / 4;
num_funcs = funcs ? (funcs->length / 4) : 0;
num_pulls = pulls ? (pulls->length / 4) : 0;
if (num_funcs > 1 && num_funcs != num_pins) {
dev_err(pc->dev,
"%s: brcm,function must have 1 or %d entries\n",
of_node_full_name(np), num_pins);
return -EINVAL;
}
if (num_pulls > 1 && num_pulls != num_pins) {
dev_err(pc->dev,
"%s: brcm,pull must have 1 or %d entries\n",
of_node_full_name(np), num_pins);
return -EINVAL;
}
maps_per_pin = 0;
if (num_funcs)
maps_per_pin++;
if (num_pulls)
maps_per_pin++;
cur_map = maps = kzalloc(num_pins * maps_per_pin * sizeof(*maps),
GFP_KERNEL);
if (!maps)
return -ENOMEM;
for (i = 0; i < num_pins; i++) {
err = of_property_read_u32_index(np, "brcm,pins", i, &pin);
if (err)
goto out;
if (pin >= ARRAY_SIZE(bcm2835_gpio_pins)) {
dev_err(pc->dev, "%s: invalid brcm,pins value %d\n",
of_node_full_name(np), pin);
err = -EINVAL;
goto out;
}
if (num_funcs) {
err = of_property_read_u32_index(np, "brcm,function",
(num_funcs > 1) ? i : 0, &func);
if (err)
goto out;
err = bcm2835_pctl_dt_node_to_map_func(pc, np, pin,
func, &cur_map);
if (err)
goto out;
}
if (num_pulls) {
err = of_property_read_u32_index(np, "brcm,pull",
(num_funcs > 1) ? i : 0, &pull);
if (err)
goto out;
err = bcm2835_pctl_dt_node_to_map_pull(pc, np, pin,
pull, &cur_map);
if (err)
goto out;
}
}
*map = maps;
*num_maps = num_pins * maps_per_pin;
return 0;
out:
kfree(maps);
return err;
}
static const struct pinctrl_ops bcm2835_pctl_ops = {
.get_groups_count = bcm2835_pctl_get_groups_count,
.get_group_name = bcm2835_pctl_get_group_name,
.get_group_pins = bcm2835_pctl_get_group_pins,
.pin_dbg_show = bcm2835_pctl_pin_dbg_show,
.dt_node_to_map = bcm2835_pctl_dt_node_to_map,
.dt_free_map = bcm2835_pctl_dt_free_map,
};
static int bcm2835_pmx_get_functions_count(struct pinctrl_dev *pctldev)
{
return BCM2835_FSEL_COUNT;
}
static const char *bcm2835_pmx_get_function_name(struct pinctrl_dev *pctldev,
unsigned selector)
{
return bcm2835_functions[selector];
}
static int bcm2835_pmx_get_function_groups(struct pinctrl_dev *pctldev,
unsigned selector,
const char * const **groups,
unsigned * const num_groups)
{
/* every pin can do every function */
*groups = bcm2835_gpio_groups;
*num_groups = ARRAY_SIZE(bcm2835_gpio_groups);
return 0;
}
static int bcm2835_pmx_set(struct pinctrl_dev *pctldev,
unsigned func_selector,
unsigned group_selector)
{
struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
bcm2835_pinctrl_fsel_set(pc, group_selector, func_selector);
return 0;
}
static void bcm2835_pmx_gpio_disable_free(struct pinctrl_dev *pctldev,
struct pinctrl_gpio_range *range,
unsigned offset)
{
struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
/* disable by setting to GPIO_IN */
bcm2835_pinctrl_fsel_set(pc, offset, BCM2835_FSEL_GPIO_IN);
}
static int bcm2835_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
struct pinctrl_gpio_range *range,
unsigned offset,
bool input)
{
struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
enum bcm2835_fsel fsel = input ?
BCM2835_FSEL_GPIO_IN : BCM2835_FSEL_GPIO_OUT;
bcm2835_pinctrl_fsel_set(pc, offset, fsel);
return 0;
}
static const struct pinmux_ops bcm2835_pmx_ops = {
.get_functions_count = bcm2835_pmx_get_functions_count,
.get_function_name = bcm2835_pmx_get_function_name,
.get_function_groups = bcm2835_pmx_get_function_groups,
.set_mux = bcm2835_pmx_set,
.gpio_disable_free = bcm2835_pmx_gpio_disable_free,
.gpio_set_direction = bcm2835_pmx_gpio_set_direction,
};
static int bcm2835_pinconf_get(struct pinctrl_dev *pctldev,
unsigned pin, unsigned long *config)
{
/* No way to read back config in HW */
return -ENOTSUPP;
}
static int bcm2835_pinconf_set(struct pinctrl_dev *pctldev,
unsigned pin, unsigned long *configs,
unsigned num_configs)
{
struct bcm2835_pinctrl *pc = pinctrl_dev_get_drvdata(pctldev);
enum bcm2835_pinconf_param param;
u16 arg;
u32 off, bit;
int i;
for (i = 0; i < num_configs; i++) {
param = BCM2835_PINCONF_UNPACK_PARAM(configs[i]);
arg = BCM2835_PINCONF_UNPACK_ARG(configs[i]);
if (param != BCM2835_PINCONF_PARAM_PULL)
return -EINVAL;
off = GPIO_REG_OFFSET(pin);
bit = GPIO_REG_SHIFT(pin);
bcm2835_gpio_wr(pc, GPPUD, arg & 3);
/*
* Docs say to wait 150 cycles, but not of what. We assume a
* 1 MHz clock here, which is pretty slow...
*/
udelay(150);
bcm2835_gpio_wr(pc, GPPUDCLK0 + (off * 4), BIT(bit));
udelay(150);
bcm2835_gpio_wr(pc, GPPUDCLK0 + (off * 4), 0);
} /* for each config */
return 0;
}
static const struct pinconf_ops bcm2835_pinconf_ops = {
.pin_config_get = bcm2835_pinconf_get,
.pin_config_set = bcm2835_pinconf_set,
};
static struct pinctrl_desc bcm2835_pinctrl_desc = {
.name = MODULE_NAME,
.pins = bcm2835_gpio_pins,
.npins = ARRAY_SIZE(bcm2835_gpio_pins),
.pctlops = &bcm2835_pctl_ops,
.pmxops = &bcm2835_pmx_ops,
.confops = &bcm2835_pinconf_ops,
.owner = THIS_MODULE,
};
static struct pinctrl_gpio_range bcm2835_pinctrl_gpio_range = {
.name = MODULE_NAME,
.npins = BCM2835_NUM_GPIOS,
};
static int bcm2835_pinctrl_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np = dev->of_node;
struct bcm2835_pinctrl *pc;
struct resource iomem;
int err, i;
BUILD_BUG_ON(ARRAY_SIZE(bcm2835_gpio_pins) != BCM2835_NUM_GPIOS);
BUILD_BUG_ON(ARRAY_SIZE(bcm2835_gpio_groups) != BCM2835_NUM_GPIOS);
pc = devm_kzalloc(dev, sizeof(*pc), GFP_KERNEL);
if (!pc)
return -ENOMEM;
platform_set_drvdata(pdev, pc);
pc->dev = dev;
err = of_address_to_resource(np, 0, &iomem);
if (err) {
dev_err(dev, "could not get IO memory\n");
return err;
}
pc->base = devm_ioremap_resource(dev, &iomem);
if (IS_ERR(pc->base))
return PTR_ERR(pc->base);
pc->gpio_chip = bcm2835_gpio_chip;
pc->gpio_chip.dev = dev;
pc->gpio_chip.of_node = np;
pc->irq_domain = irq_domain_add_linear(np, BCM2835_NUM_GPIOS,
&irq_domain_simple_ops, NULL);
if (!pc->irq_domain) {
dev_err(dev, "could not create IRQ domain\n");
return -ENOMEM;
}
for (i = 0; i < BCM2835_NUM_GPIOS; i++) {
int irq = irq_create_mapping(pc->irq_domain, i);
irq_set_lockdep_class(irq, &gpio_lock_class);
irq_set_chip_and_handler(irq, &bcm2835_gpio_irq_chip,
handle_level_irq);
irq_set_chip_data(irq, pc);
set_irq_flags(irq, IRQF_VALID);
}
for (i = 0; i < BCM2835_NUM_BANKS; i++) {
unsigned long events;
unsigned offset;
int len;
char *name;
/* clear event detection flags */
bcm2835_gpio_wr(pc, GPREN0 + i * 4, 0);
bcm2835_gpio_wr(pc, GPFEN0 + i * 4, 0);
bcm2835_gpio_wr(pc, GPHEN0 + i * 4, 0);
bcm2835_gpio_wr(pc, GPLEN0 + i * 4, 0);
bcm2835_gpio_wr(pc, GPAREN0 + i * 4, 0);
bcm2835_gpio_wr(pc, GPAFEN0 + i * 4, 0);
/* clear all the events */
events = bcm2835_gpio_rd(pc, GPEDS0 + i * 4);
for_each_set_bit(offset, &events, 32)
bcm2835_gpio_wr(pc, GPEDS0 + i * 4, BIT(offset));
pc->irq[i] = irq_of_parse_and_map(np, i);
pc->irq_data[i].pc = pc;
pc->irq_data[i].bank = i;
spin_lock_init(&pc->irq_lock[i]);
len = strlen(dev_name(pc->dev)) + 16;
name = devm_kzalloc(pc->dev, len, GFP_KERNEL);
if (!name)
return -ENOMEM;
snprintf(name, len, "%s:bank%d", dev_name(pc->dev), i);
err = devm_request_irq(dev, pc->irq[i],
bcm2835_gpio_irq_handler, IRQF_SHARED,
name, &pc->irq_data[i]);
if (err) {
dev_err(dev, "unable to request IRQ %d\n", pc->irq[i]);
return err;
}
}
err = gpiochip_add(&pc->gpio_chip);
if (err) {
dev_err(dev, "could not add GPIO chip\n");
return err;
}
pc->pctl_dev = pinctrl_register(&bcm2835_pinctrl_desc, dev, pc);
if (IS_ERR(pc->pctl_dev)) {
gpiochip_remove(&pc->gpio_chip);
return PTR_ERR(pc->pctl_dev);
}
pc->gpio_range = bcm2835_pinctrl_gpio_range;
pc->gpio_range.base = pc->gpio_chip.base;
pc->gpio_range.gc = &pc->gpio_chip;
pinctrl_add_gpio_range(pc->pctl_dev, &pc->gpio_range);
return 0;
}
static int bcm2835_pinctrl_remove(struct platform_device *pdev)
{
struct bcm2835_pinctrl *pc = platform_get_drvdata(pdev);
pinctrl_unregister(pc->pctl_dev);
gpiochip_remove(&pc->gpio_chip);
return 0;
}
static const struct of_device_id bcm2835_pinctrl_match[] = {
{ .compatible = "brcm,bcm2835-gpio" },
{}
};
MODULE_DEVICE_TABLE(of, bcm2835_pinctrl_match);
static struct platform_driver bcm2835_pinctrl_driver = {
.probe = bcm2835_pinctrl_probe,
.remove = bcm2835_pinctrl_remove,
.driver = {
.name = MODULE_NAME,
.of_match_table = bcm2835_pinctrl_match,
},
};
module_platform_driver(bcm2835_pinctrl_driver);
MODULE_AUTHOR("Chris Boot, Simon Arlott, Stephen Warren");
MODULE_DESCRIPTION("BCM2835 Pin control driver");
MODULE_LICENSE("GPL");
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