[PATCH v8] usb:serial:pl2303: add GPIOs interface on PL2303

From: Wang YanQing
Date: Sun Aug 31 2014 - 11:25:34 EST

Next message: Andi Kleen: "Re: [PATCH 0/6] hugepage migration fixes (v3)"
Previous message: Rabin Vincent: "Re: [PATCH v4 7/8] ARM: mm: allow non-text sections to be non-executable"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]

PL2303 USB Serial devices may has GPIOs, this patch add
basic PL2303 gpio support.

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.

Signed-off-by: Wang YanQing <udknight@xxxxxxxxx>
---
Note: I sniffed office HXD gpio test program to get
gpios control protocol with PL2303 RA, so I only
test it with PL2303 RA and HXA, I don't have HXD,
but because it is *office* HXD gpio test program,
so if it doesn't work with HXD, I will feel surprise.

Changes
v7-v8:
1: add support for four dedicated gpios on HXD and RA
2: fix problem reported by Johan Hovold in v7
3: fix checkpatch.pl's warning

v6-v7:
1: add generic gpio support interfaces for pl2303 USB Serial devices
in pl2303_type_data and pl2303_serial_private suggested by Andreas Mohr.
2: drop different label names for different pl2303 instance suggested by Johan Hovold.
3: fix missing lock corrected by Johan Hovold.
4: use prefix pl2303hx_gpio instead pl2303_gpio, pl2303_gpio is over generic for current code,
and now we move gpio_startup|gpio_release into type-specified data structure, so pl2303hx_gpio
is a better prefix.
5: make words in Kconfig a little more useful and clarified.
6: many misc code quality enhancement suggested by Johan Hovold.

v5-v6:
1: fix typo error in Kconfig reported by Andreas Mohr
2: add const qulification to gpio_dir_mask and gpio_value_mask suggested by Andreas Mohr

v4-v5:
1: fix gpio_chip.lable been overwrited by template_chip.
2: use idr to manage minor instead of crude monotonous atomic increment.

v3-v4:
1: fix missing static for gpio_dir_mask and gpio_value_mask
2: reduce unneeded compile macro defined suggested by gnomes@xxxxxxxxxxxxxxxxxxx
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.

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

v1-v2:
1:drop gpio-pl2303.c and relation stuff
2:hang gpio stuff off of pl2303.c

drivers/usb/serial/Kconfig | 11 ++
drivers/usb/serial/pl2303.c | 250 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 261 insertions(+)

diff --git a/drivers/usb/serial/Kconfig b/drivers/usb/serial/Kconfig
index 3ce5c74..b4e0cf9 100644
--- a/drivers/usb/serial/Kconfig
+++ b/drivers/usb/serial/Kconfig
@@ -516,6 +516,17 @@ 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 GPIOs on PL2303 USB Serial single port
+ adapter from Prolific.
+
+ It supports 2 dedicated GPIOs on PL2303HXA, 4 dedicated GPIOs on
+ PL2303HXD and PL2303RA 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 e9bad92..a3f8411 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/mutex.h>
#include "pl2303.h"

@@ -132,6 +134,22 @@ MODULE_DEVICE_TABLE(usb, id_table);
#define UART_OVERRUN_ERROR 0x40
#define UART_CTS 0x80

+#define HXD_GPIO_01_CTRL 0x0001
+#define HXD_GPIO_01_VALUE 0x0081
+#define HXD_GPIO_23_DIR_CTRL 0x0c0c
+#define HXD_GPIO_23_VALUE_CTRL 0x0d0d
+#define HXD_GPIO_23_VALUE 0x8d8d
+
+#define HXD_GPIO0_DIR_MASK 0x10
+#define HXD_GPIO1_DIR_MASK 0x20
+#define HXD_GPIO2_DIR_MASK 0x03
+#define HXD_GPIO3_DIR_MASK 0x0c
+
+#define HXD_GPIO0_VALUE_MASK 0x40
+#define HXD_GPIO1_VALUE_MASK 0x80
+#define HXD_GPIO2_VALUE_MASK 0x01
+#define HXD_GPIO3_VALUE_MASK 0x02
+

enum pl2303_type {
TYPE_01, /* Type 0 and 1 (difference unknown) */
@@ -144,9 +162,12 @@ struct pl2303_type_data {
unsigned long quirks;
};

+struct pl2303_gpio;
struct pl2303_serial_private {
const struct pl2303_type_data *type;
unsigned long quirks;
+ u8 ngpio;
+ struct pl2303_gpio *gpio;
};

struct pl2303_private {
@@ -157,6 +178,14 @@ struct pl2303_private {
u8 line_settings[7];
};

+#ifdef CONFIG_USB_SERIAL_PL2303_GPIO
+static int pl2303_gpio_startup(struct usb_serial *serial);
+static void pl2303_gpio_release(struct usb_serial *serial);
+#else
+static inline int pl2303_gpio_startup(struct usb_serial *serial) { return 0; }
+static inline void pl2303_gpio_release(struct usb_serial *serial) {}
+#endif
+
static const struct pl2303_type_data pl2303_type_data[TYPE_COUNT] = {
[TYPE_01] = {
.max_baud_rate = 1228800,
@@ -214,11 +243,213 @@ static int pl2303_probe(struct usb_serial *serial,
return 0;
}

+#ifdef CONFIG_USB_SERIAL_PL2303_GPIO
+struct pl2303_gpio_desc {
+ u8 dir_offset;
+ u8 dir_mask;
+ u16 dir_ctrl;
+ u8 value_offset;
+ u8 value_mask;
+ u16 value_ctrl;
+ u16 read_ctrl;
+};
+
+struct pl2303_gpio {
+ struct pl2303_gpio_desc *descs;
+ u8 data[3];
+ struct mutex lock;
+ struct usb_serial *serial;
+ struct gpio_chip gpio_chip;
+};
+
+static inline struct pl2303_gpio *to_pl2303_gpio(struct gpio_chip *chip)
+{
+ return container_of(chip, struct pl2303_gpio, gpio_chip);
+}
+
+static void pl2303_gpio_add(struct usb_serial *serial, u8 num, u16 read_ctrl,
+ u8 dir_offset, u8 dir_mask, u16 dir_ctrl,
+ u8 value_offset, u8 value_mask, u16 value_ctrl)
+{
+ struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
+ struct pl2303_gpio *gpio = spriv->gpio;
+
+ BUG_ON(num >= spriv->ngpio);
+ gpio->descs[num].dir_offset = dir_offset;
+ gpio->descs[num].dir_mask = dir_mask;
+ gpio->descs[num].dir_ctrl = dir_ctrl;
+
+ gpio->descs[num].value_offset = value_offset;
+ gpio->descs[num].value_mask = value_mask;
+ gpio->descs[num].value_ctrl = value_ctrl;
+
+ gpio->descs[num].read_ctrl = read_ctrl;
+}
+
+static int pl2303_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
+{
+ struct pl2303_gpio *gpio = to_pl2303_gpio(chip);
+ struct pl2303_gpio_desc *desc;
+ int ret;
+
+ mutex_lock(&gpio->lock);
+ desc = gpio->descs+offset;
+ gpio->data[desc->dir_offset] &= ~desc->dir_mask;
+ ret = pl2303_vendor_write(gpio->serial, desc->dir_ctrl,
+ gpio->data[desc->dir_offset]);
+ mutex_unlock(&gpio->lock);
+
+ return ret;
+}
+
+static int pl2303_gpio_direction_out(struct gpio_chip *chip,
+ unsigned offset, int value)
+{
+ struct pl2303_gpio *gpio = to_pl2303_gpio(chip);
+ struct pl2303_gpio_desc *desc;
+ int ret;
+
+ mutex_lock(&gpio->lock);
+ desc = gpio->descs+offset;
+ gpio->data[desc->dir_offset] |= desc->dir_mask;
+ ret = pl2303_vendor_write(gpio->serial, desc->dir_ctrl,
+ gpio->data[desc->dir_offset]);
+ if (ret)
+ goto error;
+
+ if (value)
+ gpio->data[desc->value_offset] |= desc->value_mask;
+ else
+ gpio->data[desc->value_offset] &= ~desc->value_mask;
+
+ ret = pl2303_vendor_write(gpio->serial, desc->value_ctrl,
+ gpio->data[desc->value_offset]);
+error:
+ mutex_unlock(&gpio->lock);
+
+ return ret;
+}
+
+static void pl2303_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
+{
+ struct pl2303_gpio *gpio = to_pl2303_gpio(chip);
+ struct pl2303_gpio_desc *desc;
+
+ mutex_lock(&gpio->lock);
+ desc = gpio->descs+offset;
+ if (value)
+ gpio->data[desc->value_offset] |= desc->value_mask;
+ else
+ gpio->data[desc->value_offset] &= ~desc->value_mask;
+
+ pl2303_vendor_write(gpio->serial, desc->value_ctrl,
+ gpio->data[desc->value_offset]);
+ mutex_unlock(&gpio->lock);
+}
+
+static int pl2303_gpio_get(struct gpio_chip *chip, unsigned offset)
+{
+ struct pl2303_gpio *gpio = to_pl2303_gpio(chip);
+ struct pl2303_gpio_desc *desc;
+ unsigned char *buf;
+ int value;
+
+ buf = kzalloc(1, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ mutex_lock(&gpio->lock);
+ desc = gpio->descs+offset;
+
+ if (pl2303_vendor_read(gpio->serial, desc->read_ctrl, buf)) {
+ mutex_unlock(&gpio->lock);
+ return -EIO;
+ }
+
+ value = buf[0] & desc->value_mask;
+ mutex_unlock(&gpio->lock);
+ kfree(buf);
+
+ return value;
+}
+
+static int pl2303_gpio_startup(struct usb_serial *serial)
+{
+ struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
+ struct pl2303_gpio *gpio;
+ int ret;
+
+ gpio = kzalloc(sizeof(struct pl2303_gpio), GFP_KERNEL);
+ if (!gpio)
+ return -ENOMEM;
+
+ gpio->descs = kcalloc(spriv->ngpio, sizeof(struct pl2303_gpio_desc),
+ GFP_KERNEL);
+ if (!gpio->descs) {
+ kfree(gpio);
+ return -ENOMEM;
+ }
+ spriv->gpio = gpio;
+
+ pl2303_gpio_add(serial, 0, HXD_GPIO_01_VALUE,
+ 0, HXD_GPIO0_DIR_MASK, HXD_GPIO_01_CTRL,
+ 0, HXD_GPIO0_VALUE_MASK, HXD_GPIO_01_CTRL);
+ pl2303_gpio_add(serial, 1, HXD_GPIO_01_VALUE,
+ 0, HXD_GPIO1_DIR_MASK, HXD_GPIO_01_CTRL,
+ 0, HXD_GPIO1_VALUE_MASK, HXD_GPIO_01_CTRL);
+
+ if (spriv->ngpio == 4) {
+ pl2303_gpio_add(serial, 2, HXD_GPIO_23_VALUE,
+ 1, HXD_GPIO2_DIR_MASK, HXD_GPIO_23_DIR_CTRL,
+ 2, HXD_GPIO2_VALUE_MASK,
+ HXD_GPIO_23_VALUE_CTRL);
+ pl2303_gpio_add(serial, 3, HXD_GPIO_23_VALUE,
+ 1, HXD_GPIO3_DIR_MASK, HXD_GPIO_23_DIR_CTRL,
+ 2, HXD_GPIO3_VALUE_MASK,
+ HXD_GPIO_23_VALUE_CTRL);
+ }
+
+ gpio->serial = serial;
+ mutex_init(&gpio->lock);
+
+ gpio->gpio_chip.label = "pl2303";
+ gpio->gpio_chip.owner = THIS_MODULE;
+ gpio->gpio_chip.direction_input = pl2303_gpio_direction_in;
+ gpio->gpio_chip.get = pl2303_gpio_get;
+ gpio->gpio_chip.direction_output = pl2303_gpio_direction_out;
+ gpio->gpio_chip.set = pl2303_gpio_set;
+ gpio->gpio_chip.can_sleep = true;
+ gpio->gpio_chip.ngpio = spriv->ngpio;
+ gpio->gpio_chip.base = -1;
+ gpio->gpio_chip.dev = &serial->interface->dev;
+
+ ret = gpiochip_add(&gpio->gpio_chip);
+ if (ret < 0) {
+ kfree(gpio);
+ return ret;
+ }
+ return 0;
+}
+
+static void pl2303_gpio_release(struct usb_serial *serial)
+{
+ struct pl2303_serial_private *spriv = usb_get_serial_data(serial);
+ struct pl2303_gpio *gpio = (struct pl2303_gpio *)spriv->gpio;
+
+ gpiochip_remove(&gpio->gpio_chip);
+ kfree(gpio->descs);
+ kfree(gpio);
+}
+#endif
+
static int pl2303_startup(struct usb_serial *serial)
{
struct pl2303_serial_private *spriv;
enum pl2303_type type = TYPE_01;
unsigned char *buf;
+ u16 bcdDevice;
+ u8 major_revision;
+ int ret;

spriv = kzalloc(sizeof(*spriv), GFP_KERNEL);
if (!spriv)
@@ -244,6 +475,16 @@ static int pl2303_startup(struct usb_serial *serial)
spriv->quirks = (unsigned long)usb_get_serial_data(serial);
spriv->quirks |= spriv->type->quirks;

+ spriv->ngpio = 0;
+ if (type == TYPE_HX) {
+ bcdDevice = le16_to_cpu(serial->dev->descriptor.bcdDevice);
+ major_revision = bcdDevice = bcdDevice >> 8;
+ if (major_revision == 3)
+ spriv->ngpio = 2;
+ else if (major_revision == 4)
+ spriv->ngpio = 4;
+ }
+
usb_set_serial_data(serial, spriv);

pl2303_vendor_read(serial, 0x8484, buf);
@@ -263,6 +504,13 @@ static int pl2303_startup(struct usb_serial *serial)

kfree(buf);

+ if (spriv->ngpio > 0) {
+ ret = pl2303_gpio_startup(serial);
+ if (ret) {
+ kfree(spriv);
+ return ret;
+ }
+ }
return 0;
}

@@ -270,6 +518,8 @@ static void pl2303_release(struct usb_serial *serial)
{
struct pl2303_serial_private *spriv = usb_get_serial_data(serial);

+ if (spriv->ngpio > 0)
+ pl2303_gpio_release(serial);
kfree(spriv);
}

--
1.8.5.5.dirty
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

Next message: Andi Kleen: "Re: [PATCH 0/6] hugepage migration fixes (v3)"
Previous message: Rabin Vincent: "Re: [PATCH v4 7/8] ARM: mm: allow non-text sections to be non-executable"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]