On Tue, Sep 09, 2014 at 10:24:46PM +0300, Octavian Purdila wrote:
<snip>
> +#define DLN2_GPIO_DIRECTION_IN 0
> +#define DLN2_GPIO_DIRECTION_OUT 1
> +
> +static int dln2_gpio_get_direction(struct gpio_chip *chip, unsigned offset)
> +{
> + int ret;
> + 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 len = sizeof(rsp);
> +
> + if (test_bit(offset, dln2->pin_dir_set)) {
> + rsp.value = !!test_bit(offset, dln2->pin_dir);
> + goto report;
> + }
> +
> + 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;
> + set_bit(offset, dln2->pin_dir_set);
You shouldn't set this flag until you've stored the direction.
> +
> +report:
> + switch (rsp.value) {
> + case DLN2_GPIO_DIRECTION_IN:
> + clear_bit(offset, dln2->pin_dir);
> + return 1;
> + case DLN2_GPIO_DIRECTION_OUT:
> + set_bit(offset, dln2->pin_dir);
> + 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;
> +
> + dir = dln2_gpio_get_direction(chip, offset);
> + 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),
> + };
> +
> + set_bit(offset, dln2->pin_dir_set);
Set flag after you store the direction below.
> + if (dir == DLN2_GPIO_DIRECTION_OUT)
> + set_bit(offset, dln2->pin_dir);
> + else
> + clear_bit(offset, dln2->pin_dir);
Either way, it looks like this could race with get_direction() if you
get a set_direction() while get_direction() is retrieving the direction
from the device.
This would break gpio_get().
> +
> + return dln2_transfer(dln2->pdev, DLN2_GPIO_PIN_SET_DIRECTION,
> + &req, sizeof(req), NULL, NULL);
> +}
<snip>
> +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);
> +}
<snip>
> +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);
Again, don't do non-trivial intialisations when declaring your variables.
> + int i, ret;
> +
> + 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;
> +
> + 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;
> + }
> +
> + 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;
> +
> + platform_set_drvdata(pdev, dln2);
> +
> + ret = gpiochip_add(&dln2->gpio);
> + if (ret < 0) {
> + dev_err(dev, "failed to add gpio chip: %d\n", ret);
> + goto out;
> + }
> +
> + 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);
> + goto out_gpiochip_remove;
> + }
> +
> + 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);
> + goto out_gpiochip_remove;
> + }
> +
> + return 0;
> +
> +out_gpiochip_remove:
> + gpiochip_remove(&dln2->gpio);
> +out:
> + return ret;
> +}
> +
> +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;
> + gpiochip_remove(&dln2->gpio);
You probably need to flush all your work structs here.
> +
> + return 0;
> +}
> +
> +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.bal...@intel.com");
> +MODULE_DESCRIPTION(DRIVER_NAME "driver");
> +MODULE_LICENSE("GPL");
Johan
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