From 2c36867719d93db8d7f365310587578ab980762c Mon Sep 17 00:00:00 2001

From: Linus Walleij <linus.walleij@linaro.org>

Date: Wed, 15 Apr 2020 21:24:48 +0200

Subject: [PATCH] usb: fusb302: Convert to use GPIO descriptors

This converts the FUSB302 driver to use GPIO descriptors.

The conversion to descriptors per se is pretty straight-forward.

In the process I discovered that:

1. The driver uses a completely undocumented device tree binding

   for the interrupt GPIO line, "fcs,int_n". Ooops.

2. The undocumented binding, presumably since it has not seen

   review, is just "fcs,int_n", lacking the compulsory "-gpios"

   suffix and also something that is not a good name because

   the "_n" implies the line is inverted which is something we

   handle with flags in the device tree. Ooops.

3. Possibly the driver should not be requesting the line as a

   GPIO and request the corresponding interrupt line by open

   coding, the GPIO chip is very likely doubleing as an IRQ

   controller and can probably provide an interrupt directly

   for this line with interrupts-extended = <&gpio0 ...>;

4. Possibly the IRQ should just be tagged on the I2C client node

   in the device tree like apparently ACPI does, as it overrides

   this IRQ with client->irq if that exists.

But now it is too late to do much about that and as I can see

this is used like this in the Pinebook which is a shipping product

so let'a just contain the mess and move on.

The property currently appears in:

arch/arm64/boot/dts/rockchip/rk3399-pinebook-pro.dts

Create a quirk in the GPIO OF library to allow this property

specifically to be specified without the "-gpios" suffix, we have

other such bindings already.

Cc: Tobias Schramm <t.schramm@manjaro.org>

Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>

Cc: Yueyao Zhu <yueyao@google.com>

Cc: Guenter Roeck <linux@roeck-us.net>

Cc: devicetree@vger.kernel.org

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

Link: https://lore.kernel.org/r/20200415192448.305257-1-linus.walleij@linaro.org

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---

 drivers/gpio/gpiolib-of.c        | 21 +++++++++++++++++++++

 drivers/usb/typec/tcpm/fusb302.c | 32 +++++++++-----------------------

 2 files changed, 30 insertions(+), 23 deletions(-)

diff --git a/drivers/gpio/gpiolib-of.c b/drivers/gpio/gpiolib-of.c

index ccc449df3792a..20c2c428168e4 100644

--- a/drivers/gpio/gpiolib-of.c

+++ b/drivers/gpio/gpiolib-of.c

@@ -460,6 +460,24 @@ static struct gpio_desc *of_find_arizona_gpio(struct device *dev,

 	return of_get_named_gpiod_flags(dev->of_node, con_id, 0, of_flags);

 }

+static struct gpio_desc *of_find_usb_gpio(struct device *dev,

+					  const char *con_id,

+					  enum of_gpio_flags *of_flags)

+{

+	/*

+	 * Currently this USB quirk is only for the Fairchild FUSB302 host which is using

+	 * an undocumented DT GPIO line named "fcs,int_n" without the compulsory "-gpios"

+	 * suffix.

+	 */

+	if (!IS_ENABLED(CONFIG_TYPEC_FUSB302))

+		return ERR_PTR(-ENOENT);

+

+	if (!con_id || strcmp(con_id, "fcs,int_n"))

+		return ERR_PTR(-ENOENT);

+

+	return of_get_named_gpiod_flags(dev->of_node, con_id, 0, of_flags);

+}

+

 struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,

 			       unsigned int idx, unsigned long *flags)

 {

@@ -504,6 +522,9 @@ struct gpio_desc *of_find_gpio(struct device *dev, const char *con_id,

 	if (PTR_ERR(desc) == -ENOENT)

 		desc = of_find_arizona_gpio(dev, con_id, &of_flags);

+	if (PTR_ERR(desc) == -ENOENT)

+		desc = of_find_usb_gpio(dev, con_id, &of_flags);

+

 	if (IS_ERR(desc))

 		return desc;

diff --git a/drivers/usb/typec/tcpm/fusb302.c b/drivers/usb/typec/tcpm/fusb302.c

index b498960ff72b5..b28facece43c4 100644

--- a/drivers/usb/typec/tcpm/fusb302.c

+++ b/drivers/usb/typec/tcpm/fusb302.c

@@ -9,14 +9,13 @@

 #include <linux/delay.h>

 #include <linux/errno.h>

 #include <linux/extcon.h>

-#include <linux/gpio.h>

+#include <linux/gpio/consumer.h>

 #include <linux/i2c.h>

 #include <linux/interrupt.h>

 #include <linux/kernel.h>

 #include <linux/module.h>

 #include <linux/mutex.h>

 #include <linux/of_device.h>

-#include <linux/of_gpio.h>

 #include <linux/pinctrl/consumer.h>

 #include <linux/proc_fs.h>

 #include <linux/regulator/consumer.h>

@@ -83,7 +82,7 @@ struct fusb302_chip {

 	struct work_struct irq_work;

 	bool irq_suspended;

 	bool irq_while_suspended;

-	int gpio_int_n;

+	struct gpio_desc *gpio_int_n;

 	int gpio_int_n_irq;

 	struct extcon_dev *extcon;

@@ -1618,30 +1617,17 @@ static void fusb302_irq_work(struct work_struct *work)

 static int init_gpio(struct fusb302_chip *chip)

 {

-	struct device_node *node;

+	struct device *dev = chip->dev;

 	int ret = 0;

-	node = chip->dev->of_node;

-	chip->gpio_int_n = of_get_named_gpio(node, "fcs,int_n", 0);

-	if (!gpio_is_valid(chip->gpio_int_n)) {

-		ret = chip->gpio_int_n;

-		dev_err(chip->dev, "cannot get named GPIO Int_N, ret=%d", ret);

-		return ret;

-	}

-	ret = devm_gpio_request(chip->dev, chip->gpio_int_n, "fcs,int_n");

-	if (ret < 0) {

-		dev_err(chip->dev, "cannot request GPIO Int_N, ret=%d", ret);

-		return ret;

-	}

-	ret = gpio_direction_input(chip->gpio_int_n);

-	if (ret < 0) {

-		dev_err(chip->dev,

-			"cannot set GPIO Int_N to input, ret=%d", ret);

-		return ret;

+	chip->gpio_int_n = devm_gpiod_get(dev, "fcs,int_n", GPIOD_IN);

+	if (IS_ERR(chip->gpio_int_n)) {

+		dev_err(dev, "failed to request gpio_int_n\n");

+		return PTR_ERR(chip->gpio_int_n);

 	}

-	ret = gpio_to_irq(chip->gpio_int_n);

+	ret = gpiod_to_irq(chip->gpio_int_n);

 	if (ret < 0) {

-		dev_err(chip->dev,

+		dev_err(dev,

 			"cannot request IRQ for GPIO Int_N, ret=%d", ret);

 		return ret;

 	}

-- 

2.26.2