Re: [PATCH v3 3/3] gpio: add support for the Diolan DLN-2 USB GPIO driver
From: Johan Hovold
Date: Mon Sep 08 2014 - 12:24:15 EST
On Fri, Sep 05, 2014 at 06:17:59PM +0300, Octavian Purdila wrote:
> From: Daniel Baluta <daniel.baluta@xxxxxxxxx>
>
> This patch adds GPIO and IRQ support for the Diolan DLN-2 GPIO module.
>
> Information about the USB protocol interface can be found in the
> Programmer's Reference Manual [1], see section 2.9 for the GPIO
> module commands and responses.
>
> [1] https://www.diolan.com/downloads/dln-api-manual.pdf
>
> Signed-off-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
> Signed-off-by: Octavian Purdila <octavian.purdila@xxxxxxxxx>
> ---
> drivers/gpio/Kconfig | 12 ++
> drivers/gpio/Makefile | 1 +
> drivers/gpio/gpio-dln2.c | 537 +++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 550 insertions(+)
> create mode 100644 drivers/gpio/gpio-dln2.c
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 9de1515..6a9e352 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -897,4 +897,16 @@ config GPIO_VIPERBOARD
> River Tech's viperboard.h for detailed meaning
> of the module parameters.
>
> +config GPIO_DLN2
> + tristate "Diolan DLN2 GPIO support"
> + depends on USB && MFD_DLN2
Just MFD_DLN2.
> + select GPIOLIB_IRQCHIP
> +
> + help
> + Select this option to enable GPIO driver for the Diolan DLN2
> + board.
> +
> + This driver can also be built as a module. If so, the module
> + will be called gpio-dln2.
> +
> endif
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index 5d024e3..eaa97a0 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -26,6 +26,7 @@ obj-$(CONFIG_GPIO_CRYSTAL_COVE) += gpio-crystalcove.o
> obj-$(CONFIG_GPIO_DA9052) += gpio-da9052.o
> obj-$(CONFIG_GPIO_DA9055) += gpio-da9055.o
> obj-$(CONFIG_GPIO_DAVINCI) += gpio-davinci.o
> +obj-$(CONFIG_GPIO_DLN2) += gpio-dln2.o
> obj-$(CONFIG_GPIO_DWAPB) += gpio-dwapb.o
> obj-$(CONFIG_GPIO_EM) += gpio-em.o
> obj-$(CONFIG_GPIO_EP93XX) += gpio-ep93xx.o
> diff --git a/drivers/gpio/gpio-dln2.c b/drivers/gpio/gpio-dln2.c
> new file mode 100644
> index 0000000..f8c0bcb
> --- /dev/null
> +++ b/drivers/gpio/gpio-dln2.c
> @@ -0,0 +1,537 @@
> +/*
> + * 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/errno.h>
> +#include <linux/module.h>
> +#include <linux/slab.h>
> +#include <linux/types.h>
> +#include <linux/mutex.h>
> +#include <linux/irqdomain.h>
> +#include <linux/irq.h>
> +#include <linux/irqchip/chained_irq.h>
> +#include <linux/usb.h>
> +#include <linux/gpio.h>
> +#include <linux/gpio/driver.h>
> +#include <linux/ptrace.h>
> +#include <linux/wait.h>
> +#include <linux/platform_device.h>
> +#include <linux/mfd/dln2.h>
> +
> +#define DRIVER_NAME "dln2-gpio"
> +
> +#define DLN2_GPIO_ID 0x01
> +
> +#define DLN2_GPIO_GET_PORT_COUNT DLN2_CMD(0x00, DLN2_GPIO_ID)
> +#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_irq_work {
> + struct work_struct work;
> + struct dln2_gpio *dln2;
> + int pin, type;
One declaration per line.
Please consider my previous style comments also for this patch.
> +};
> +
> +struct dln2_remove_work {
> + struct delayed_work work;
> + struct dln2_gpio *dln2;
> +};
> +
> +struct dln2_gpio {
> + struct platform_device *pdev;
> + struct gpio_chip gpio;
> +
> + DECLARE_BITMAP(irqs_masked, DLN2_GPIO_MAX_PINS);
> + DECLARE_BITMAP(irqs_enabled, DLN2_GPIO_MAX_PINS);
> + DECLARE_BITMAP(irqs_pending, DLN2_GPIO_MAX_PINS);
> + struct dln2_irq_work irq_work[DLN2_GPIO_MAX_PINS];
> + struct dln2_remove_work remove_work;
> +};
> +
> +struct dln2_gpio_pin {
> + __le16 pin;
> +} __packed;
> +
> +struct dln2_gpio_pin_val {
> + __le16 pin;
> + u8 value;
> +} __packed;
> +
> +static int dln2_gpio_get_pin_count(struct platform_device *pdev)
> +{
> + __le16 count;
> + int ret, len = sizeof(count);
Dito.
> +
> + ret = dln2_transfer(pdev, DLN2_GPIO_GET_PIN_COUNT, NULL, 0, &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(dln2->pdev, cmd, &req, sizeof(req), NULL, NULL);
> +}
> +
> +static int dln2_gpio_pin_val(struct dln2_gpio *dln2, int cmd, unsigned int pin)
> +{
> + struct dln2_gpio_pin req = {
> + .pin = cpu_to_le16(pin),
> + };
> + struct dln2_gpio_pin_val rsp;
> + int ret, 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 = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_VAL, pin);
Dito.
> +
> + if (ret < 0)
> + return ret;
> + return !!ret;
> +}
> +
> +static int dln2_gpio_pin_get_out_val(struct dln2_gpio *dln2, unsigned int pin)
> +{
> + int ret = dln2_gpio_pin_val(dln2, DLN2_GPIO_PIN_GET_OUT_VAL, pin);
> +
> + if (ret < 0)
> + return ret;
> + return !!ret;
> +}
> +
> +static void 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 = cpu_to_le16(value),
> + };
> +
> + dln2_transfer(dln2->pdev, DLN2_GPIO_PIN_SET_OUT_VAL, &req, sizeof(req),
> + NULL, NULL);
> +}
> +
> +static int dln2_gpio_request(struct gpio_chip *chip, unsigned offset)
> +{
> + struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio);
> +
> + return dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_ENABLE, offset);
> +}
> +
> +static void dln2_gpio_free(struct gpio_chip *chip, unsigned offset)
> +{
> + struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio);
> +
> + dln2_gpio_pin_cmd(dln2, DLN2_GPIO_PIN_DISABLE, offset);
> +}
> +
> +#define DLN2_GPIO_DIRECTION_IN 0
> +#define DLN2_GPIO_DIRECTION_OUT 1
> +
> +static int dln2_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
> +{
> + struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio);
> + struct dln2_gpio_pin req = {
> + .pin = cpu_to_le16(offset),
> + };
> + struct dln2_gpio_pin_val rsp;
> + int ret, len = sizeof(rsp);
> +
> + 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)
> + return -EPROTO;
> +
> + switch (rsp.value) {
> + case DLN2_GPIO_DIRECTION_IN:
> + return 1;
> + case DLN2_GPIO_DIRECTION_OUT:
> + return 0;
> + default:
> + return -EPROTO;
> + }
> +}
> +
> +static int dln2_gpio_get(struct gpio_chip *chip, unsigned int offset)
> +{
> + struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio);
> + int dir = dln2_gpio_get_direction(chip, offset);
Do you really want the overhead of this call for every get?
> +
> + if (dir < 0)
> + return dir;
> +
> + if (dir)
> + 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 = container_of(chip, struct dln2_gpio, gpio);
> +
> + 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 = container_of(chip, struct dln2_gpio, gpio);
> + struct dln2_gpio_pin_val req = {
> + .pin = cpu_to_le16(offset),
> + .value = cpu_to_le16(dir),
> + };
> +
> + return dln2_transfer(dln2->pdev, DLN2_GPIO_PIN_SET_DIRECTION,
> + &req, sizeof(req), NULL, NULL);
> +}
> +
> +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)
> +{
> + return dln2_gpio_set_direction(chip, offset, DLN2_GPIO_DIRECTION_OUT);
> +}
> +
> +static int dln2_gpio_set_debounce(struct gpio_chip *chip, unsigned offset,
> + unsigned debounce)
> +{
> + struct dln2_gpio *dln2 = container_of(chip, struct dln2_gpio, gpio);
> + struct {
> + __le32 duration;
> + } __packed req = {
> + .duration = cpu_to_le32(debounce),
> + };
> +
> + return dln2_transfer(dln2->pdev, DLN2_GPIO_SET_DEBOUNCE,
> + &req, sizeof(req), NULL, NULL);
> +}
> +
> +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(dln2->pdev, DLN2_GPIO_PIN_SET_EVENT_CFG,
> + &req, sizeof(req), NULL, NULL);
> +}
> +
> +static void dln2_irq_work(struct work_struct *w)
> +{
> + struct dln2_irq_work *iw = container_of(w, struct dln2_irq_work, work);
> + struct dln2_gpio *dln2 = iw->dln2;
> + u8 type = iw->type & DLN2_GPIO_EVENT_MASK;
> +
> + if (test_bit(iw->pin, dln2->irqs_enabled))
> + dln2_gpio_set_event_cfg(dln2, iw->pin, type, 0);
> + else
> + dln2_gpio_set_event_cfg(dln2, iw->pin, DLN2_GPIO_EVENT_NONE, 0);
> +}
> +
> +static void dln2_irq_enable(struct irq_data *irqd)
> +{
> + struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
> + struct dln2_gpio *dln2 = container_of(gc, struct dln2_gpio, gpio);
> + int pin = irqd_to_hwirq(irqd);
> +
> + set_bit(pin, dln2->irqs_enabled);
> + schedule_work(&dln2->irq_work[pin].work);
> +}
> +
> +static void dln2_irq_disable(struct irq_data *irqd)
> +{
> + struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
> + struct dln2_gpio *dln2 = container_of(gc, struct dln2_gpio, gpio);
> + int pin = irqd_to_hwirq(irqd);
> +
> + clear_bit(pin, dln2->irqs_enabled);
> + schedule_work(&dln2->irq_work[pin].work);
> +}
> +
> +static void dln2_irq_mask(struct irq_data *irqd)
> +{
> + struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
> + struct dln2_gpio *dln2 = container_of(gc, struct dln2_gpio, gpio);
> + int pin = irqd_to_hwirq(irqd);
> +
> + set_bit(pin, dln2->irqs_masked);
> +}
> +
> +static void dln2_irq_unmask(struct irq_data *irqd)
> +{
> + struct gpio_chip *gc = irq_data_get_irq_chip_data(irqd);
> + struct dln2_gpio *dln2 = container_of(gc, struct dln2_gpio, gpio);
> + int pin = irqd_to_hwirq(irqd);
> +
> + if (test_and_clear_bit(pin, dln2->irqs_pending))
> + generic_handle_irq(pin);
> +}
> +
> +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 = container_of(gc, struct dln2_gpio, gpio);
> + int pin = irqd_to_hwirq(irqd);
> +
> + switch (type) {
> + case IRQ_TYPE_LEVEL_HIGH:
> + dln2->irq_work[pin].type = DLN2_GPIO_EVENT_LVL_HIGH;
> + break;
> + case IRQ_TYPE_LEVEL_LOW:
> + dln2->irq_work[pin].type = DLN2_GPIO_EVENT_LVL_LOW;
> + break;
> + case IRQ_TYPE_EDGE_BOTH:
> + dln2->irq_work[pin].type = DLN2_GPIO_EVENT_CHANGE;
> + break;
> + case IRQ_TYPE_EDGE_RISING:
> + dln2->irq_work[pin].type = DLN2_GPIO_EVENT_CHANGE_RISING;
> + break;
> + case IRQ_TYPE_EDGE_FALLING:
> + dln2->irq_work[pin].type = DLN2_GPIO_EVENT_CHANGE_FALLING;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static struct irq_chip dln2_gpio_irqchip = {
> + .name = "dln2-irq",
> + .irq_enable = dln2_irq_enable,
> + .irq_disable = dln2_irq_disable,
> + .irq_mask = dln2_irq_mask,
> + .irq_unmask = dln2_irq_unmask,
> + .irq_set_type = dln2_irq_set_type,
> +};
> +
> +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;
You never verify the length of the received data before parsing it.
> + struct dln2_gpio *dln2 = platform_get_drvdata(pdev);
> +
> + pin = le16_to_cpu(event->pin);
> + irq = irq_find_mapping(dln2->gpio.irqdomain, pin);
> +
> + if (!irq) {
> + dev_err(dln2->gpio.dev, "pin %d not mapped to IRQ\n", pin);
> + return;
> + }
> +
> + if (!test_bit(pin, dln2->irqs_enabled))
> + return;
> + if (test_bit(pin, dln2->irqs_masked)) {
> + set_bit(pin, dln2->irqs_pending);
> + return;
> + }
> +
> + switch (dln2->irq_work[pin].type) {
> + 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_do_remove(struct dln2_gpio *dln2)
> +{
> + /* When removing the DLN2 USB device, gpiochip_remove may fail
> + * due to i2c drivers holding a GPIO pin. However, the i2c bus
> + * will eventually be removed triggering an i2c driver remove
> + * which will release the GPIO pin. So retrying the operation
> + * later should succeed. */
> + int ret = gpiochip_remove(&dln2->gpio);
> + struct device *dev = dln2->gpio.dev;
> +
> + if (ret < 0) {
> + if (ret == -EBUSY)
> + schedule_delayed_work(&dln2->remove_work.work, HZ/10);
> + else
> + dev_warn(dev, "error removing gpio chip: %d\n", ret);
> + } else {
> + kfree(dln2);
> + }
> +
> + return ret;
> +}
Wow. You really need to get rid of this hack.
As I already mentioned when you first posted this, the return value of
gpiochip_remove is going away. Furthermore, this is not a problem
specific to this driver, so if anything this would belong in gpiolib.
And finally, as I also mentioned, a gpio may stay requested
indefinitely so you could be looping here forever.
> +
> +static void dln2_remove_work(struct work_struct *w)
> +{
> + struct delayed_work *dw = to_delayed_work(w);
> + struct dln2_remove_work *rw = container_of(dw, struct dln2_remove_work,
> + work);
> + struct dln2_gpio *dln2 = rw->dln2;
> +
> + dln2_do_remove(dln2);
> +}
> +
> +static int dln2_gpio_probe(struct platform_device *pdev)
> +{
> + struct dln2_gpio *dln2;
> + struct device *dev = &pdev->dev;
> + int pins = dln2_gpio_get_pin_count(pdev), i, ret;
> +
> + if (pins < 0) {
> + dev_err(dev, "failed to get pin count: %d\n", pins);
> + return pins;
> + }
> + if (pins > DLN2_GPIO_MAX_PINS)
> + dev_warn(dev, "clamping pins to %d\n", DLN2_GPIO_MAX_PINS);
You never seem to actually clamp the number of pins, as you set set
ngpio bases on pins below. This is bound to lead to crashes eventually.
> +
> + dln2 = kzalloc(sizeof(*dln2), GFP_KERNEL);
> + if (!dln2)
> + return -ENOMEM;
> +
> + for (i = 0; i < DLN2_GPIO_MAX_PINS; i++) {
> + INIT_WORK(&dln2->irq_work[i].work, dln2_irq_work);
> + dln2->irq_work[i].pin = i;
> + dln2->irq_work[i].dln2 = dln2;
> + }
> + INIT_DELAYED_WORK(&dln2->remove_work.work, dln2_remove_work);
> + dln2->remove_work.dln2 = dln2;
> +
> + ret = dln2_register_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV,
> + dln2_gpio_event);
> + if (ret) {
> + kfree(dln2);
> + return ret;
> + }
> +
> + dln2->pdev = pdev;
> +
> + dln2->gpio.label = "dln2";
> + dln2->gpio.dev = dev;
> + dln2->gpio.owner = THIS_MODULE;
> + dln2->gpio.base = -1;
> + dln2->gpio.ngpio = pins;
> + dln2->gpio.exported = 1;
> + 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_debounce = dln2_gpio_set_debounce;
> +
> + ret = gpiochip_add(&dln2->gpio);
> + if (ret < 0) {
> + dev_err(dev, "failed to add gpio chip: %d\n", ret);
> + dln2_unregister_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV);
> + kfree(dln2);
You should probably add a common error path for this.
> + 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);
> + dln2_unregister_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV);
> + gpiochip_remove(&dln2->gpio);
> + kfree(dln2);
> + return ret;
> + }
You dereference the platform data in dln2_gpio_event, which could
possibly be NULL if you get a callback here.
> +
> + platform_set_drvdata(pdev, dln2);
> +
> + return 0;
> +}
> +
> +static int dln2_gpio_remove(struct platform_device *pdev)
> +{
> + struct dln2_gpio *dln2 = platform_get_drvdata(pdev);
> +
> + dln2_unregister_event_cb(pdev, DLN2_GPIO_CONDITION_MET_EV);
> + dln2->pdev = NULL;
> +
> + return dln2_do_remove(dln2);
> +}
> +
> +static struct platform_driver dln2_gpio_driver = {
> + .driver.name = DRIVER_NAME,
> + .driver.owner = THIS_MODULE,
> + .probe = dln2_gpio_probe,
> + .remove = dln2_gpio_remove,
> +};
> +
> +module_platform_driver(dln2_gpio_driver);
> +
> +MODULE_AUTHOR("Daniel Baluta <daniel.baluta@xxxxxxxxx");
> +MODULE_DESCRIPTION(DRIVER_NAME "driver");
> +MODULE_LICENSE("GPL");
Johan
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