| Message ID | 1410290686-6680-4-git-send-email-octavian.purdila@intel.com |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
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.baluta@intel.com"); > +MODULE_DESCRIPTION(DRIVER_NAME "driver"); > +MODULE_LICENSE("GPL"); Johan -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Sep 18, 2014 at 1:54 PM, Johan Hovold <johan@kernel.org> wrote: > 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(). > I don't think gpio_set_direction() and gpio_get() are allowed to race. I think the user must make sure the right direction is set before issuing gpio_get(), otherwise it can read invalid values even if gpio_get() would not depend on get_direction(). I will fix the calls to pin_dir_set to be made after the pin_dir calls. -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Sep 18, 2014 at 03:43:07PM +0300, Octavian Purdila wrote: > On Thu, Sep 18, 2014 at 1:54 PM, Johan Hovold <johan@kernel.org> wrote: > > On Tue, Sep 09, 2014 at 10:24:46PM +0300, Octavian Purdila wrote: > > 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(). > > > I don't think gpio_set_direction() and gpio_get() are allowed to race. I wrote that set_direction() and get_direction() could race, which in turn would break gpio_get() as you would be caching the wrong direction setting. But perhaps gpiolib prevents this from happening. Johan -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Sep 18, 2014 at 3:46 PM, Johan Hovold <johan@kernel.org> wrote: > On Thu, Sep 18, 2014 at 03:43:07PM +0300, Octavian Purdila wrote: >> On Thu, Sep 18, 2014 at 1:54 PM, Johan Hovold <johan@kernel.org> wrote: >> > On Tue, Sep 09, 2014 at 10:24:46PM +0300, Octavian Purdila wrote: > >> > 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(). >> > >> I don't think gpio_set_direction() and gpio_get() are allowed to race. > > I wrote that set_direction() and get_direction() could race, which in > turn would break gpio_get() as you would be caching the wrong > direction setting. > OK, I now see the problem. I think doing this in get_direction() will fix the issue: if (!test_and_set_bit(offset, dln2->pin_dir_set)) set/clear_bit(offset, dln2->pin_dir); because gpiolib calls get_direction() while requesting a pin and request cannot race with itself. Which means that get_direction() can not race with itself the first time it is called, when the set/clear operation will be run. And because we know that get_direction() is called first, we can even remove the set/clear operation from set_direction(). -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Thu, Sep 18, 2014 at 06:54:34PM +0300, Octavian Purdila wrote: > On Thu, Sep 18, 2014 at 3:46 PM, Johan Hovold <johan@kernel.org> wrote: > > On Thu, Sep 18, 2014 at 03:43:07PM +0300, Octavian Purdila wrote: > >> On Thu, Sep 18, 2014 at 1:54 PM, Johan Hovold <johan@kernel.org> wrote: > >> > On Tue, Sep 09, 2014 at 10:24:46PM +0300, Octavian Purdila wrote: > > > >> > 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(). > >> > > >> I don't think gpio_set_direction() and gpio_get() are allowed to race. > > > > I wrote that set_direction() and get_direction() could race, which in > > turn would break gpio_get() as you would be caching the wrong > > direction setting. > > > > OK, I now see the problem. I think doing this in get_direction() will > fix the issue: > > if (!test_and_set_bit(offset, dln2->pin_dir_set)) > set/clear_bit(offset, dln2->pin_dir); > > because gpiolib calls get_direction() while requesting a pin and > request cannot race with itself. Which means that get_direction() can > not race with itself the first time it is called, when the set/clear > operation will be run. > > And because we know that get_direction() is called first, we can even > remove the set/clear operation from set_direction(). Why not simply fetch the direction in request() and get rid of the pin_dir_set bitmask? Johan -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 9de1515..44ec206 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 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..23ed2ed --- /dev/null +++ b/drivers/gpio/gpio-dln2.c @@ -0,0 +1,529 @@ +/* + * 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/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 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; + int type; +}; + +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(pin_dir_set, DLN2_GPIO_MAX_PINS); + DECLARE_BITMAP(pin_dir, DLN2_GPIO_MAX_PINS); + + 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_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) +{ + int ret; + __le16 count; + int len = sizeof(count); + + 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) +{ + 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 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) +{ + 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); + +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); + if (dir == DLN2_GPIO_DIRECTION_OUT) + set_bit(offset, dln2->pin_dir); + else + clear_bit(offset, dln2->pin_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; + struct dln2_gpio *dln2 = platform_get_drvdata(pdev); + + if (len < sizeof(*event)) { + dev_err(dln2->gpio.dev, "short event message\n"); + return; + } + + 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_gpio_probe(struct platform_device *pdev) +{ + struct dln2_gpio *dln2; + struct device *dev = &pdev->dev; + int pins = dln2_gpio_get_pin_count(pdev); + 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); + + 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.baluta@intel.com"); +MODULE_DESCRIPTION(DRIVER_NAME "driver"); +MODULE_LICENSE("GPL");