lkml.org 
[lkml]   [2014]   [Jul]   [24]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH v4] usb:serial:pl2303: add GPIOs interface on PL2303
PL2303HX has two GPIOs, this patch add interface for it.

Signed-off-by: Wang YanQing <udknight@gmail.com>
---
Changes v3-v4:
1: fix missing static for gpio_dir_mask and gpio_value_mask
2: reduce unneeded compile macro defined suggested by gnomes@lxorguk.ukuu.org.uk
3: use true instead of 1 corrected by Linus Walleij
4: ignore return value of gpiochip_remove suggested by Linus Walleij
5: fix multi gpio_chips registered by pl2303 can't be distinguished in kernel space.

Give different labels to different gpio_chips is good for diagnostic,
and we could identify per gpio_chip registered by pl2303 by try different
lable name then detect its parent device.


drivers/usb/serial/Kconfig | 10 +++
drivers/usb/serial/pl2303.c | 163 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 173 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..f5c0df6 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -28,6 +28,8 @@
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <asm/unaligned.h>
+#include <linux/gpio.h>
+#include <linux/atomic.h>
#include "pl2303.h"


@@ -143,9 +145,25 @@ struct pl2303_type_data {
unsigned long quirks;
};

+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;
+};
+
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 +231,145 @@ static int pl2303_probe(struct usb_serial *serial,
return 0;
}

+#ifdef CONFIG_USB_SERIAL_PL2303_GPIO
+#define GPIO_NUM (2)
+static u8 gpio_dir_mask[GPIO_NUM] = {0x10, 0x20};
+static u8 gpio_value_mask[GPIO_NUM] = {0x40, 0x80};
+static atomic_t gpio_chip_index = ATOMIC_INIT(-1);
+
+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 const struct gpio_chip template_chip = {
+ .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 = true,
+};
+
+static int pl2303_gpio_startup(struct usb_serial *serial)
+{
+ struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
+ char *label;
+ int ret;
+
+ if (spriv->type != &pl2303_type_data[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");
+ return -ENOMEM;
+ }
+
+ spriv->gpio->index = 0x00;
+ spriv->gpio->serial = serial;
+
+ label = kasprintf(GFP_KERNEL, "pl2303-gpio%d",
+ atomic_inc_return(&gpio_chip_index));
+ if (label == NULL) {
+ kfree(spriv->gpio);
+ spriv->gpio = NULL;
+ return -ENOMEM;
+ }
+ spriv->gpio->gpio_chip.label = label;
+ 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->gpio_chip.label);
+ kfree(spriv->gpio);
+ spriv->gpio = NULL;
+ }
+ return 0;
+}
+
+static void pl2303_gpio_release(struct usb_serial *serial)
+{
+ struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
+
+ if (spriv->gpio) {
+ gpiochip_remove(&spriv->gpio->gpio_chip);
+ kfree(spriv->gpio->gpio_chip.label);
+ kfree(spriv->gpio);
+ spriv->gpio = NULL;
+ }
+}
+#endif
+
static int pl2303_startup(struct usb_serial *serial)
{
struct pl2303_serial_private *spriv;
@@ -262,6 +419,9 @@ static int pl2303_startup(struct usb_serial *serial)

kfree(buf);

+#ifdef CONFIG_USB_SERIAL_PL2303_GPIO
+ pl2303_gpio_startup(serial);
+#endif
return 0;
}

@@ -269,6 +429,9 @@ static void pl2303_release(struct usb_serial *serial)
{
struct pl2303_serial_private *spriv = usb_get_serial_data(serial);

+#ifdef CONFIG_USB_SERIAL_PL2303_GPIO
+ pl2303_gpio_release(serial);
+#endif
kfree(spriv);
}

--
1.8.5.5.dirty

\
 
 \ /
  Last update: 2014-07-24 19:41    [W:0.044 / U:25.204 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site