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linux-next/drivers/pinctrl/pinctrl-bcm2835.c
Fan Wu 2243a87d90 pinctrl: avoid duplicated calling enable_pinmux_setting for a pin 
What the patch does:
1. Call pinmux_disable_setting ahead of pinmux_enable_setting
  each time pinctrl_select_state is called
2. Remove the HW disable operation in pinmux_disable_setting function.
3. Remove the disable ops in struct pinmux_ops
4. Remove all the disable ops users in current code base.

Notes:
1. Great thanks for the suggestion from Linus, Tony Lindgren and
   Stephen Warren and Everyone that shared comments on this patch.
2. The patch also includes comment fixes from Stephen Warren.

The reason why we do this:
1. To avoid duplicated calling of the enable_setting operation
   without disabling operation inbetween which will let the pin
   descriptor desc->mux_usecount increase monotonously.
2. The HW pin disable operation is not useful for any of the
   existing platforms.
   And this can be used to avoid the HW glitch after using the
   item #1 modification.

In the following case, the issue can be reproduced:
1. There is a driver that need to switch pin state dynamically,
   e.g. between "sleep" and "default" state
2. The pin setting configuration in a DTS node may be like this:

  component a {
	pinctrl-names = "default", "sleep";
	pinctrl-0 = <&a_grp_setting &c_grp_setting>;
	pinctrl-1 = <&b_grp_setting &c_grp_setting>;
  }

  The "c_grp_setting" config node is totally identical, maybe like
  following one:

  c_grp_setting: c_grp_setting {
	pinctrl-single,pins = <GPIO48 AF6>;
  }

3. When switching the pin state in the following official pinctrl
   sequence:
	pin = pinctrl_get();
	state = pinctrl_lookup_state(wanted_state);
	pinctrl_select_state(state);
	pinctrl_put();

Test Result:
1. The switch is completed as expected, that is: the device's
   pin configuration is changed according to the description in the
   "wanted_state" group setting
2. The "desc->mux_usecount" of the corresponding pins in "c_group"
   is increased without being decreased, because the "desc" is for
   each physical pin while the setting is for each setting node
   in the DTS.
   Thus, if the "c_grp_setting" in pinctrl-0 is not disabled ahead
   of enabling "c_grp_setting" in pinctrl-1, the desc->mux_usecount
   will keep increasing without any chance to be decreased.

According to the comments in the original code, only the setting,
in old state but not in new state, will be "disabled" (calling
pinmux_disable_setting), which is correct logic but not intact. We
still need consider case that the setting is in both old state
and new state. We can do this in the following two ways:

1. Avoid to "enable"(calling pinmux_enable_setting) the "same pin
   setting" repeatedly
2. "Disable"(calling pinmux_disable_setting) the "same pin setting",
   actually two setting instances, ahead of enabling them.

Analysis:
1. The solution #2 is better because it can avoid too much
   iteration.
2. If we disable all of the settings in the old state and one of
   the setting(s) exist in the new state, the pins mux function
   change may happen when some SoC vendors defined the
   "pinctrl-single,function-off"
   in their DTS file.
   old_setting => disabled_setting => new_setting.
3. In the pinmux framework, when a pin state is switched, the
   setting in the old state should be marked as "disabled".

Conclusion:
1. To Remove the HW disabling operation to above the glitch mentioned
   above.
2. Handle the issue mentioned above by disabling all of the settings
   in old state and then enable the all of the settings in new state.

Signed-off-by: Fan Wu <fwu@marvell.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Patrice Chotard <patrice.chotard@st.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Maxime Coquelin <maxime.coquelin@st.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2014-07-11 14:08:26 +02:00

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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];
/* ack edge triggered IRQs immediately */
if (!(type & IRQ_TYPE_LEVEL_MASK))
bcm2835_gpio_set_bit(pc, GPEDS0, gpio);
generic_handle_irq(irq_linear_revmap(pc->irq_domain, gpio));
/* ack level triggered IRQ after handling them */
if (type & IRQ_TYPE_LEVEL_MASK)
bcm2835_gpio_set_bit(pc, GPEDS0, 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_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);
spin_unlock_irqrestore(&pc->irq_lock[bank], flags);
return ret;
}
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,
};
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_enable(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,
.enable = bcm2835_pmx_enable,
.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_simple_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 (!pc->pctl_dev) {
gpiochip_remove(&pc->gpio_chip);
return -EINVAL;
}
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 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,
.owner = THIS_MODULE,
.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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