[PATCH v3] usb:serial:pl2303: add GPIOs interface on PL2303
From: Wang YanQing
Date: Sun Jul 20 2014 - 22:51:05 EST
PL2303HX has two GPIOs, this patch add interface for it.
Signed-off-by: Wang YanQing <udknight@xxxxxxxxx>
---
Changes v2-v3:
1: fix errors and warnings reported by Daniele Forsi checked with checkpatch.pl
2: fix missing GPIOLIB dependence in Kconfig
3: fix pl2303_gpio_get can't work
Known issue:
If gpios are in use(export to userspace through sysfs interface, etc),
then call pl2303_release(unplug usb-serial convertor, modprobe -r, etc),
will cause trouble, so we need to make sure there is no gpio user before
call pl2303_release.
drivers/usb/serial/Kconfig | 10 ++++
drivers/usb/serial/pl2303.c | 141 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 151 insertions(+)
diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig
index 3ce5c74..4bc0d0f 100644
--- a/drivers/usb/serial/Kconfig
+++ b/drivers/usb/serial/Kconfig
@@ -516,6 +516,16 @@ config USB_SERIAL_PL2303
To compile this driver as a module, choose M here: the
module will be called pl2303.
+config USB_SERIAL_PL2303_GPIO
+ bool "USB Prolific 2303 Single Port GPIOs support"
+ depends on USB_SERIAL_PL2303 && GPIOLIB
+ ---help---
+ Say Y here if you want to use the GPIOs on PL2303 USB Serial single port
+ adapter from Prolific.
+
+ It support 2 GPIOs on PL2303HX currently,
+ if unsure, say N.
+
config USB_SERIAL_OTI6858
tristate "USB Ours Technology Inc. OTi-6858 USB To RS232 Bridge Controller"
help
diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index b3d5a35..bedf6ea 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -28,6 +28,9 @@
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <asm/unaligned.h>
+#ifdef CONFIG_USB_SERIAL_PL2303_GPIO
+#include <linux/gpio.h>
+#endif
#include "pl2303.h"
@@ -143,9 +146,32 @@ struct pl2303_type_data {
unsigned long quirks;
};
+#ifdef CONFIG_USB_SERIAL_PL2303_GPIO
+#define GPIO_NUM (2)
+
+struct pl2303_gpio {
+ /*
+ * 0..3: unknown (zero)
+ * 4: gp0 output enable (1: gp0 pin is output, 0: gp0 pin is input)
+ * 5: gp1 output enable (1: gp1 pin is output, 0: gp1 pin is input)
+ * 6: gp0 pin value
+ * 7: gp1 pin value
+ */
+ u8 index;
+ struct usb_serial *serial;
+ struct gpio_chip gpio_chip;
+};
+
+u8 gpio_dir_mask[GPIO_NUM] = {0x10, 0x20};
+u8 gpio_value_mask[GPIO_NUM] = {0x40, 0x80};
+#endif
+
struct pl2303_serial_private {
const struct pl2303_type_data *type;
unsigned long quirks;
+#ifdef CONFIG_USB_SERIAL_PL2303_GPIO
+ struct pl2303_gpio *gpio;
+#endif
};
struct pl2303_private {
@@ -213,6 +239,84 @@ static int pl2303_probe(struct usb_serial *serial,
return 0;
}
+#ifdef CONFIG_USB_SERIAL_PL2303_GPIO
+static inline struct pl2303_gpio *to_pl2303_gpio(struct gpio_chip *chip)
+{
+ return container_of(chip, struct pl2303_gpio, gpio_chip);
+}
+
+static int pl2303_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
+{
+ struct pl2303_gpio *gpio = to_pl2303_gpio(chip);
+
+ if (offset >= chip->ngpio)
+ return -EINVAL;
+
+ gpio->index &= ~gpio_dir_mask[offset];
+ pl2303_vendor_write(gpio->serial, 1, gpio->index);
+ return 0;
+}
+
+static int pl2303_gpio_direction_out(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ struct pl2303_gpio *gpio = to_pl2303_gpio(chip);
+
+ if (offset >= chip->ngpio)
+ return -EINVAL;
+
+ gpio->index |= gpio_dir_mask[offset];
+ if (value)
+ gpio->index |= gpio_value_mask[offset];
+ else
+ gpio->index &= ~gpio_value_mask[offset];
+
+ pl2303_vendor_write(gpio->serial, 1, gpio->index);
+ return 0;
+}
+
+static void pl2303_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct pl2303_gpio *gpio = to_pl2303_gpio(chip);
+
+ if (offset >= chip->ngpio)
+ return;
+
+ if (value)
+ gpio->index |= gpio_value_mask[offset];
+ else
+ gpio->index &= ~gpio_value_mask[offset];
+
+ pl2303_vendor_write(gpio->serial, 1, gpio->index);
+}
+
+static int pl2303_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct pl2303_gpio *gpio = to_pl2303_gpio(chip);
+ unsigned char buf[1];
+ int value = 0;
+
+ if (offset >= chip->ngpio)
+ return -EINVAL;
+
+ if (pl2303_vendor_read(gpio->serial, 0x0081, buf))
+ return -EIO;
+
+ value = buf[0] & gpio_value_mask[offset];
+ return value;
+}
+
+static struct gpio_chip template_chip = {
+ .label = "pl2303-gpio",
+ .owner = THIS_MODULE,
+ .direction_input = pl2303_gpio_direction_in,
+ .get = pl2303_gpio_get,
+ .direction_output = pl2303_gpio_direction_out,
+ .set = pl2303_gpio_set,
+ .can_sleep = 1,
+};
+#endif
+
static int pl2303_startup(struct usb_serial *serial)
{
struct pl2303_serial_private *spriv;
@@ -262,6 +366,35 @@ static int pl2303_startup(struct usb_serial *serial)
kfree(buf);
+#ifdef CONFIG_USB_SERIAL_PL2303_GPIO
+ if (type != TYPE_HX)
+ return 0;
+
+ spriv->gpio = kzalloc(sizeof(struct pl2303_gpio), GFP_KERNEL);
+ if (spriv->gpio == NULL) {
+ dev_err(&serial->interface->dev,
+ "Failed to allocate pl2303_gpio\n");
+ } else {
+ int ret;
+
+ spriv->gpio->index = 0x00;
+ spriv->gpio->serial = serial;
+ spriv->gpio->gpio_chip = template_chip;
+ spriv->gpio->gpio_chip.ngpio = GPIO_NUM;
+ spriv->gpio->gpio_chip.base = -1;
+ spriv->gpio->gpio_chip.dev = &serial->interface->dev;
+ /* initialize GPIOs, input mode as default */
+ pl2303_vendor_write(spriv->gpio->serial, 1, spriv->gpio->index);
+
+ ret = gpiochip_add(&spriv->gpio->gpio_chip);
+ if (ret < 0) {
+ dev_err(&serial->interface->dev,
+ "Could not register gpiochip, %d\n", ret);
+ kfree(spriv->gpio);
+ spriv->gpio = NULL;
+ }
+ }
+#endif
return 0;
}
@@ -269,6 +402,14 @@ static void pl2303_release(struct usb_serial *serial)
{
struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
+#ifdef CONFIG_USB_SERIAL_PL2303_GPIO
+ if (spriv && spriv->gpio) {
+ if (gpiochip_remove(&spriv->gpio->gpio_chip))
+ dev_err(&serial->interface->dev,
+ "unable to remove gpio_chip?\n");
+ kfree(spriv->gpio);
+ }
+#endif
kfree(spriv);
}
--
1.8.5.5.dirty
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