linux/drivers/gpio/gpio-dln2.c
Mika Westerberg 2956b5d94a pinctrl / gpio: Introduce .set_config() callback for GPIO chips
Currently we already have two pin configuration related callbacks
available for GPIO chips .set_single_ended() and .set_debounce(). In
future we expect to have even more, which does not scale well if we need
to add yet another callback to the GPIO chip structure for each possible
configuration parameter.

Better solution is to reuse what we already have available in the
generic pinconf.

To support this, we introduce a new .set_config() callback for GPIO
chips. The callback takes a single packed pin configuration value as
parameter. This can then be extended easily beyond what is currently
supported by just adding new types to the generic pinconf enum.

If the GPIO driver is backed up by a pinctrl driver the GPIO driver can
just assign gpiochip_generic_config() (introduced in this patch) to
.set_config and that will take care configuration requests are directed
to the pinctrl driver.

We then convert the existing drivers over .set_config() and finally
remove the .set_single_ended() and .set_debounce() callbacks.

Suggested-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-26 15:27:37 +01:00

527 lines
13 KiB
C

/*
* Driver for the Diolan DLN-2 USB-GPIO adapter
*
* Copyright (c) 2014 Intel Corporation
*
* 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, version 2.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/irqdomain.h>
#include <linux/irq.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/gpio.h>
#include <linux/gpio/driver.h>
#include <linux/platform_device.h>
#include <linux/mfd/dln2.h>
#define DLN2_GPIO_ID 0x01
#define DLN2_GPIO_GET_PIN_COUNT DLN2_CMD(0x01, DLN2_GPIO_ID)
#define DLN2_GPIO_SET_DEBOUNCE DLN2_CMD(0x04, DLN2_GPIO_ID)
#define DLN2_GPIO_GET_DEBOUNCE DLN2_CMD(0x05, DLN2_GPIO_ID)
#define DLN2_GPIO_PORT_GET_VAL DLN2_CMD(0x06, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_GET_VAL DLN2_CMD(0x0B, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_SET_OUT_VAL DLN2_CMD(0x0C, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_GET_OUT_VAL DLN2_CMD(0x0D, DLN2_GPIO_ID)
#define DLN2_GPIO_CONDITION_MET_EV DLN2_CMD(0x0F, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_ENABLE DLN2_CMD(0x10, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_DISABLE DLN2_CMD(0x11, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_SET_DIRECTION DLN2_CMD(0x13, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_GET_DIRECTION DLN2_CMD(0x14, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_SET_EVENT_CFG DLN2_CMD(0x1E, DLN2_GPIO_ID)
#define DLN2_GPIO_PIN_GET_EVENT_CFG DLN2_CMD(0x1F, DLN2_GPIO_ID)
#define DLN2_GPIO_EVENT_NONE 0
#define DLN2_GPIO_EVENT_CHANGE 1
#define DLN2_GPIO_EVENT_LVL_HIGH 2
#define DLN2_GPIO_EVENT_LVL_LOW 3
#define DLN2_GPIO_EVENT_CHANGE_RISING 0x11
#define DLN2_GPIO_EVENT_CHANGE_FALLING 0x21
#define DLN2_GPIO_EVENT_MASK 0x0F
#define DLN2_GPIO_MAX_PINS 32
struct dln2_gpio {
struct platform_device *pdev;
struct gpio_chip gpio;
/*
* Cache pin direction to save us one transfer, since the hardware has
* separate commands to read the in and out values.
*/
DECLARE_BITMAP(output_enabled, DLN2_GPIO_MAX_PINS);
/* active IRQs - not synced to hardware */
DECLARE_BITMAP(unmasked_irqs, DLN2_GPIO_MAX_PINS);
/* active IRQS - synced to hardware */
DECLARE_BITMAP(enabled_irqs, DLN2_GPIO_MAX_PINS);
int irq_type[DLN2_GPIO_MAX_PINS];
struct mutex irq_lock;
};
struct dln2_gpio_pin {
__le16 pin;
};
struct dln2_gpio_pin_val {
__le16 pin __packed;
u8 value;
};
static int dln2_gpio_get_pin_count(struct platform_device *pdev)
{
int ret;
__le16 count;
int len = sizeof(count);
ret = dln2_transfer_rx(pdev, DLN2_GPIO_GET_PIN_COUNT, &count, &len);
if (ret < 0)
return ret;
if (len < sizeof(count))
return -EPROTO;
return le16_to_cpu(count);
}
static int dln2_gpio_pin_cmd(struct dln2_gpio *dln2, int cmd, unsigned pin)
{
struct dln2_gpio_pin req = {
.pin = cpu_to_le16(pin),
};
return dln2_transfer_tx(dln2->pdev, cmd, &req, sizeof(req));
}
static int dln2_gpio_pin_val(struct dln2_gpio *dln2, int cmd, unsigned int pin)
{
int ret;
struct dln2_gpio_pin req = {
.pin = cpu_to_le16(pin),
};
struct dln2_gpio_pin_val rsp;
int len = sizeof(rsp);
ret = dln2_transfer(dln2->pdev, cmd, &req, sizeof(req), &rsp, &len);
if (ret < 0)
return ret;
if (len < sizeof(rsp) || req.pin != rsp.pin)
return -EPROTO;
return rsp.value;
}
static int dln2_gpio_pin_get_in_val(struct dln2_gpio *dln2, unsigned int pin)
{
int ret;
ret = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_VAL, pin);
if (ret < 0)
return ret;
return !!ret;
}
static int dln2_gpio_pin_get_out_val(struct dln2_gpio *dln2, unsigned int pin)
{
int ret;
ret = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_OUT_VAL, pin);
if (ret < 0)
return ret;
return !!ret;
}
static int dln2_gpio_pin_set_out_val(struct dln2_gpio *dln2,
unsigned int pin, int value)
{
struct dln2_gpio_pin_val req = {
.pin = cpu_to_le16(pin),
.value = value,
};
return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_OUT_VAL, &req,
sizeof(req));
}
#define DLN2_GPIO_DIRECTION_IN 0
#define DLN2_GPIO_DIRECTION_OUT 1
static int dln2_gpio_request(struct gpio_chip *chip, unsigned offset)
{
struct dln2_gpio *dln2 = gpiochip_get_data(chip);
struct dln2_gpio_pin req = {
.pin = cpu_to_le16(offset),
};
struct dln2_gpio_pin_val rsp;
int len = sizeof(rsp);
int ret;
ret = dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_ENABLE, offset);
if (ret < 0)
return ret;
/* cache the pin direction */
ret = dln2_transfer(dln2->pdev, DLN2_GPIO_PIN_GET_DIRECTION,
&req, sizeof(req), &rsp, &len);
if (ret < 0)
return ret;
if (len < sizeof(rsp) || req.pin != rsp.pin) {
ret = -EPROTO;
goto out_disable;
}
switch (rsp.value) {
case DLN2_GPIO_DIRECTION_IN:
clear_bit(offset, dln2->output_enabled);
return 0;
case DLN2_GPIO_DIRECTION_OUT:
set_bit(offset, dln2->output_enabled);
return 0;
default:
ret = -EPROTO;
goto out_disable;
}
out_disable:
dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_DISABLE, offset);
return ret;
}
static void dln2_gpio_free(struct gpio_chip *chip, unsigned offset)
{
struct dln2_gpio *dln2 = gpiochip_get_data(chip);
dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_DISABLE, offset);
}
static int dln2_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
{
struct dln2_gpio *dln2 = gpiochip_get_data(chip);
if (test_bit(offset, dln2->output_enabled))
return GPIOF_DIR_OUT;
return GPIOF_DIR_IN;
}
static int dln2_gpio_get(struct gpio_chip *chip, unsigned int offset)
{
struct dln2_gpio *dln2 = gpiochip_get_data(chip);
int dir;
dir = dln2_gpio_get_direction(chip, offset);
if (dir < 0)
return dir;
if (dir == GPIOF_DIR_IN)
return dln2_gpio_pin_get_in_val(dln2, offset);
return dln2_gpio_pin_get_out_val(dln2, offset);
}
static void dln2_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
{
struct dln2_gpio *dln2 = gpiochip_get_data(chip);
dln2_gpio_pin_set_out_val(dln2, offset, value);
}
static int dln2_gpio_set_direction(struct gpio_chip *chip, unsigned offset,
unsigned dir)
{
struct dln2_gpio *dln2 = gpiochip_get_data(chip);
struct dln2_gpio_pin_val req = {
.pin = cpu_to_le16(offset),
.value = dir,
};
int ret;
ret = dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_DIRECTION,
&req, sizeof(req));
if (ret < 0)
return ret;
if (dir == DLN2_GPIO_DIRECTION_OUT)
set_bit(offset, dln2->output_enabled);
else
clear_bit(offset, dln2->output_enabled);
return ret;
}
static int dln2_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
{
return dln2_gpio_set_direction(chip, offset, DLN2_GPIO_DIRECTION_IN);
}
static int dln2_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
int value)
{
struct dln2_gpio *dln2 = gpiochip_get_data(chip);
int ret;
ret = dln2_gpio_pin_set_out_val(dln2, offset, value);
if (ret < 0)
return ret;
return dln2_gpio_set_direction(chip, offset, DLN2_GPIO_DIRECTION_OUT);
}
static int dln2_gpio_set_config(struct gpio_chip *chip, unsigned offset,
unsigned long config)
{
struct dln2_gpio *dln2 = gpiochip_get_data(chip);
__le32 duration;
if (pinconf_to_config_param(config) != PIN_CONFIG_INPUT_DEBOUNCE)
return -ENOTSUPP;
duration = cpu_to_le32(pinconf_to_config_argument(config));
return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_SET_DEBOUNCE,
&duration, sizeof(duration));
}
static int dln2_gpio_set_event_cfg(struct dln2_gpio *dln2, unsigned pin,
unsigned type, unsigned period)
{
struct {
__le16 pin;
u8 type;
__le16 period;
} __packed req = {
.pin = cpu_to_le16(pin),
.type = type,
.period = cpu_to_le16(period),
};
return dln2_transfer_tx(dln2->pdev, DLN2_GPIO_PIN_SET_EVENT_CFG,
&req, sizeof(req));
}
static void dln2_irq_unmask(struct irq_data *irqd)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
struct dln2_gpio *dln2 = gpiochip_get_data(gc);
int pin = irqd_to_hwirq(irqd);
set_bit(pin, dln2->unmasked_irqs);
}
static void dln2_irq_mask(struct irq_data *irqd)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
struct dln2_gpio *dln2 = gpiochip_get_data(gc);
int pin = irqd_to_hwirq(irqd);
clear_bit(pin, dln2->unmasked_irqs);
}
static int dln2_irq_set_type(struct irq_data *irqd, unsigned type)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
struct dln2_gpio *dln2 = gpiochip_get_data(gc);
int pin = irqd_to_hwirq(irqd);
switch (type) {
case IRQ_TYPE_LEVEL_HIGH:
dln2->irq_type[pin] = DLN2_GPIO_EVENT_LVL_HIGH;
break;
case IRQ_TYPE_LEVEL_LOW:
dln2->irq_type[pin] = DLN2_GPIO_EVENT_LVL_LOW;
break;
case IRQ_TYPE_EDGE_BOTH:
dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE;
break;
case IRQ_TYPE_EDGE_RISING:
dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE_RISING;
break;
case IRQ_TYPE_EDGE_FALLING:
dln2->irq_type[pin] = DLN2_GPIO_EVENT_CHANGE_FALLING;
break;
default:
return -EINVAL;
}
return 0;
}
static void dln2_irq_bus_lock(struct irq_data *irqd)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
struct dln2_gpio *dln2 = gpiochip_get_data(gc);
mutex_lock(&dln2->irq_lock);
}
static void dln2_irq_bus_unlock(struct irq_data *irqd)
{
struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
struct dln2_gpio *dln2 = gpiochip_get_data(gc);
int pin = irqd_to_hwirq(irqd);
int enabled, unmasked;
unsigned type;
int ret;
enabled = test_bit(pin, dln2->enabled_irqs);
unmasked = test_bit(pin, dln2->unmasked_irqs);
if (enabled != unmasked) {
if (unmasked) {
type = dln2->irq_type[pin] & DLN2_GPIO_EVENT_MASK;
set_bit(pin, dln2->enabled_irqs);
} else {
type = DLN2_GPIO_EVENT_NONE;
clear_bit(pin, dln2->enabled_irqs);
}
ret = dln2_gpio_set_event_cfg(dln2, pin, type, 0);
if (ret)
dev_err(dln2->gpio.parent, "failed to set event\n");
}
mutex_unlock(&dln2->irq_lock);
}
static struct irq_chip dln2_gpio_irqchip = {
.name = "dln2-irq",
.irq_mask = dln2_irq_mask,
.irq_unmask = dln2_irq_unmask,
.irq_set_type = dln2_irq_set_type,
.irq_bus_lock = dln2_irq_bus_lock,
.irq_bus_sync_unlock = dln2_irq_bus_unlock,
};
static void dln2_gpio_event(struct platform_device *pdev, u16 echo,
const void *data, int len)
{
int pin, irq;
const struct {
__le16 count;
__u8 type;
__le16 pin;
__u8 value;
} __packed *event = data;
struct dln2_gpio *dln2 = platform_get_drvdata(pdev);
if (len < sizeof(*event)) {
dev_err(dln2->gpio.parent, "short event message\n");
return;
}
pin = le16_to_cpu(event->pin);
if (pin >= dln2->gpio.ngpio) {
dev_err(dln2->gpio.parent, "out of bounds pin %d\n", pin);
return;
}
irq = irq_find_mapping(dln2->gpio.irqdomain, pin);
if (!irq) {
dev_err(dln2->gpio.parent, "pin %d not mapped to IRQ\n", pin);
return;
}
switch (dln2->irq_type[pin]) {
case DLN2_GPIO_EVENT_CHANGE_RISING:
if (event->value)
generic_handle_irq(irq);
break;
case DLN2_GPIO_EVENT_CHANGE_FALLING:
if (!event->value)
generic_handle_irq(irq);
break;
default:
generic_handle_irq(irq);
}
}
static int dln2_gpio_probe(struct platform_device *pdev)
{
struct dln2_gpio *dln2;
struct device *dev = &pdev->dev;
int pins;
int ret;
pins = dln2_gpio_get_pin_count(pdev);
if (pins < 0) {
dev_err(dev, "failed to get pin count: %d\n", pins);
return pins;
}
if (pins > DLN2_GPIO_MAX_PINS) {
pins = DLN2_GPIO_MAX_PINS;
dev_warn(dev, "clamping pins to %d\n", DLN2_GPIO_MAX_PINS);
}
dln2 = devm_kzalloc(&pdev->dev, sizeof(*dln2), GFP_KERNEL);
if (!dln2)
return -ENOMEM;
mutex_init(&dln2->irq_lock);
dln2->pdev = pdev;
dln2->gpio.label = "dln2";
dln2->gpio.parent = dev;
dln2->gpio.owner = THIS_MODULE;
dln2->gpio.base = -1;
dln2->gpio.ngpio = pins;
dln2->gpio.can_sleep = true;
dln2->gpio.set = dln2_gpio_set;
dln2->gpio.get = dln2_gpio_get;
dln2->gpio.request = dln2_gpio_request;
dln2->gpio.free = dln2_gpio_free;
dln2->gpio.get_direction = dln2_gpio_get_direction;
dln2->gpio.direction_input = dln2_gpio_direction_input;
dln2->gpio.direction_output = dln2_gpio_direction_output;
dln2->gpio.set_config = dln2_gpio_set_config;
platform_set_drvdata(pdev, dln2);
ret = devm_gpiochip_add_data(dev, &dln2->gpio, dln2);
if (ret < 0) {
dev_err(dev, "failed to add gpio chip: %d\n", ret);
return ret;
}
ret = gpiochip_irqchip_add(&dln2->gpio, &dln2_gpio_irqchip, 0,
handle_simple_irq, IRQ_TYPE_NONE);
if (ret < 0) {
dev_err(dev, "failed to add irq chip: %d\n", ret);
return ret;
}
ret = dln2_register_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV,
dln2_gpio_event);
if (ret) {
dev_err(dev, "failed to register event cb: %d\n", ret);
return ret;
}
return 0;
}
static int dln2_gpio_remove(struct platform_device *pdev)
{
dln2_unregister_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV);
return 0;
}
static struct platform_driver dln2_gpio_driver = {
.driver.name = "dln2-gpio",
.probe = dln2_gpio_probe,
.remove = dln2_gpio_remove,
};
module_platform_driver(dln2_gpio_driver);
MODULE_AUTHOR("Daniel Baluta <daniel.baluta@intel.com");
MODULE_DESCRIPTION("Driver for the Diolan DLN2 GPIO interface");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS("platform:dln2-gpio");