The driver core supports the ability to handle the creation and removal
of device-specific sysfs files in a race-free manner. Moreover, it can
guarantee the success of creation. Therefore, it should be better to
move the code and convert to use dev_groups.
Signed-off-by: Jiasheng Jiang <jiasheng@xxxxxxxxxxx>
---
Changelog:
v3 -> v4:
1. Move the code and remove the pre-definitions.
v2 -> v3:
1. Add is_visible to filter the unneeded files.
v1 -> v2:
1. Change the title.
2. Switch to use an attribute group.
---
drivers/usb/serial/ftdi_sio.c | 275 +++++++++++++++++-----------------
1 file changed, 135 insertions(+), 140 deletions(-)
diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index d5a3986dfee7..c06ad75ba6d7 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1108,10 +1108,145 @@ static u32 ftdi_232bm_baud_to_divisor(int baud);
static u32 ftdi_2232h_baud_base_to_divisor(int baud, int base);
static u32 ftdi_2232h_baud_to_divisor(int baud);
+
+#define WDR_TIMEOUT 5000 /* default urb timeout */
+#define WDR_SHORT_TIMEOUT 1000 /* shorter urb timeout */
+
+static int write_latency_timer(struct usb_serial_port *port)
+{
+ struct ftdi_private *priv = usb_get_serial_port_data(port);
+ struct usb_device *udev = port->serial->dev;
+ int rv;
+ int l = priv->latency;
+
+ if (priv->chip_type == SIO || priv->chip_type == FT8U232AM)
+ return -EINVAL;
+
+ if (priv->flags & ASYNC_LOW_LATENCY)
+ l = 1;
+
+ dev_dbg(&port->dev, "%s: setting latency timer = %i\n", __func__, l);
+
+ rv = usb_control_msg(udev,
+ usb_sndctrlpipe(udev, 0),
+ FTDI_SIO_SET_LATENCY_TIMER_REQUEST,
+ FTDI_SIO_SET_LATENCY_TIMER_REQUEST_TYPE,
+ l, priv->interface,
+ NULL, 0, WDR_TIMEOUT);
+ if (rv < 0)
+ dev_err(&port->dev, "Unable to write latency timer: %i\n", rv);
+ return rv;
+}
+
+static ssize_t latency_timer_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct usb_serial_port *port = to_usb_serial_port(dev);
+ struct ftdi_private *priv = usb_get_serial_port_data(port);
+
+ if (priv->flags & ASYNC_LOW_LATENCY)
+ return sprintf(buf, "1\n");
+ else
+ return sprintf(buf, "%u\n", priv->latency);
+}
+
+/* Write a new value of the latency timer, in units of milliseconds. */
+static ssize_t latency_timer_store(struct device *dev,
+ struct device_attribute *attr,
+ const char *valbuf, size_t count)
+{
+ struct usb_serial_port *port = to_usb_serial_port(dev);
+ struct ftdi_private *priv = usb_get_serial_port_data(port);
+ u8 v;
+ int rv;
+
+ if (kstrtou8(valbuf, 10, &v))
+ return -EINVAL;
+
+ priv->latency = v;
+ rv = write_latency_timer(port);
+ if (rv < 0)
+ return -EIO;
+ return count;
+}
+static DEVICE_ATTR_RW(latency_timer);
+
+/*
+ * Write an event character directly to the FTDI register. The ASCII
+ * value is in the low 8 bits, with the enable bit in the 9th bit.
+ */
+static ssize_t event_char_store(struct device *dev,
+ struct device_attribute *attr, const char *valbuf, size_t count)
+{
+ struct usb_serial_port *port = to_usb_serial_port(dev);
+ struct ftdi_private *priv = usb_get_serial_port_data(port);
+ struct usb_device *udev = port->serial->dev;
+ unsigned int v;
+ int rv;
+
+ if (kstrtouint(valbuf, 0, &v) || v >= 0x200)
+ return -EINVAL;
+
+ dev_dbg(&port->dev, "%s: setting event char = 0x%03x\n", __func__, v);
+
+ rv = usb_control_msg(udev,
+ usb_sndctrlpipe(udev, 0),
+ FTDI_SIO_SET_EVENT_CHAR_REQUEST,
+ FTDI_SIO_SET_EVENT_CHAR_REQUEST_TYPE,
+ v, priv->interface,
+ NULL, 0, WDR_TIMEOUT);
+ if (rv < 0) {
+ dev_dbg(&port->dev, "Unable to write event character: %i\n", rv);
+ return -EIO;
+ }
+
+ return count;
+}
+static DEVICE_ATTR_WO(event_char);
+
+static umode_t ftdi_sio_attr_is_visible(struct kobject *kobj,
+ struct attribute *attr, int idx)
+{
+ struct device *dev = kobj_to_dev(kobj);
+ struct usb_serial_port *port = container_of(dev, struct usb_serial_port, dev);
+ struct ftdi_private *priv = usb_get_serial_port_data(port);
+ umode_t mode = attr->mode;
+
+ if (attr == &dev_attr_latency_timer.attr) {
+ if (priv->chip_type == FT232BM ||
+ priv->chip_type == FT2232C ||
+ priv->chip_type == FT232RL ||
+ priv->chip_type == FT2232H ||
+ priv->chip_type == FT4232H ||
+ priv->chip_type == FT232H ||
+ priv->chip_type == FTX) {
+ return mode;
+ }
+ }
+ return 0;
+}
+
+static struct attribute *ftdi_sio_attrs[] = {
+ &dev_attr_event_char.attr,
+ &dev_attr_latency_timer.attr,
+ NULL,
+};
+
+static const struct attribute_group ftdi_sio_group = {
+ .attrs = ftdi_sio_attrs,
+ .is_visible = ftdi_sio_attr_is_visible,
+};
+
+static const struct attribute_group *ftdi_sio_groups[] = {
+ &ftdi_sio_group,
+ NULL
+};
+
static struct usb_serial_driver ftdi_sio_device = {
.driver = {
.owner = THIS_MODULE,
.name = "ftdi_sio",
+ .dev_groups = ftdi_sio_groups,
},
.description = "FTDI USB Serial Device",
.id_table = id_table_combined,
@@ -1144,9 +1279,6 @@ static struct usb_serial_driver * const serial_drivers[] = {
};
-#define WDR_TIMEOUT 5000 /* default urb timeout */
-#define WDR_SHORT_TIMEOUT 1000 /* shorter urb timeout */
-
/*
* ***************************************************************************
* Utility functions
@@ -1413,32 +1545,6 @@ static int change_speed(struct tty_struct *tty, struct usb_serial_port *port)
return rv;
}
-static int write_latency_timer(struct usb_serial_port *port)
-{
- struct ftdi_private *priv = usb_get_serial_port_data(port);
- struct usb_device *udev = port->serial->dev;
- int rv;
- int l = priv->latency;
-
- if (priv->chip_type == SIO || priv->chip_type == FT8U232AM)
- return -EINVAL;
-
- if (priv->flags & ASYNC_LOW_LATENCY)
- l = 1;
-
- dev_dbg(&port->dev, "%s: setting latency timer = %i\n", __func__, l);
-
- rv = usb_control_msg(udev,
- usb_sndctrlpipe(udev, 0),
- FTDI_SIO_SET_LATENCY_TIMER_REQUEST,
- FTDI_SIO_SET_LATENCY_TIMER_REQUEST_TYPE,
- l, priv->interface,
- NULL, 0, WDR_TIMEOUT);
- if (rv < 0)
- dev_err(&port->dev, "Unable to write latency timer: %i\n", rv);
- return rv;
-}
-
static int _read_latency_timer(struct usb_serial_port *port)
{
struct ftdi_private *priv = usb_get_serial_port_data(port);
@@ -1666,114 +1772,6 @@ static void ftdi_set_max_packet_size(struct usb_serial_port *port)
* ***************************************************************************
*/
-static ssize_t latency_timer_show(struct device *dev,
- struct device_attribute *attr, char *buf)
-{
- struct usb_serial_port *port = to_usb_serial_port(dev);
- struct ftdi_private *priv = usb_get_serial_port_data(port);
- if (priv->flags & ASYNC_LOW_LATENCY)
- return sprintf(buf, "1\n");
- else
- return sprintf(buf, "%u\n", priv->latency);
-}
-
-/* Write a new value of the latency timer, in units of milliseconds. */
-static ssize_t latency_timer_store(struct device *dev,
- struct device_attribute *attr,
- const char *valbuf, size_t count)
-{
- struct usb_serial_port *port = to_usb_serial_port(dev);
- struct ftdi_private *priv = usb_get_serial_port_data(port);
- u8 v;
- int rv;
-
- if (kstrtou8(valbuf, 10, &v))
- return -EINVAL;
-
- priv->latency = v;
- rv = write_latency_timer(port);
- if (rv < 0)
- return -EIO;
- return count;
-}
-static DEVICE_ATTR_RW(latency_timer);
-
-/* Write an event character directly to the FTDI register. The ASCII
- value is in the low 8 bits, with the enable bit in the 9th bit. */
-static ssize_t event_char_store(struct device *dev,
- struct device_attribute *attr, const char *valbuf, size_t count)
-{
- struct usb_serial_port *port = to_usb_serial_port(dev);
- struct ftdi_private *priv = usb_get_serial_port_data(port);
- struct usb_device *udev = port->serial->dev;
- unsigned int v;
- int rv;
-
- if (kstrtouint(valbuf, 0, &v) || v >= 0x200)
- return -EINVAL;
-
- dev_dbg(&port->dev, "%s: setting event char = 0x%03x\n", __func__, v);
-
- rv = usb_control_msg(udev,
- usb_sndctrlpipe(udev, 0),
- FTDI_SIO_SET_EVENT_CHAR_REQUEST,
- FTDI_SIO_SET_EVENT_CHAR_REQUEST_TYPE,
- v, priv->interface,
- NULL, 0, WDR_TIMEOUT);
- if (rv < 0) {
- dev_dbg(&port->dev, "Unable to write event character: %i\n", rv);
- return -EIO;
- }
-
- return count;
-}
-static DEVICE_ATTR_WO(event_char);
-
-static int create_sysfs_attrs(struct usb_serial_port *port)
-{
- struct ftdi_private *priv = usb_get_serial_port_data(port);
- int retval = 0;
-
- /* XXX I've no idea if the original SIO supports the event_char
- * sysfs parameter, so I'm playing it safe. */
- if (priv->chip_type != SIO) {
- dev_dbg(&port->dev, "sysfs attributes for %s\n", ftdi_chip_name[priv->chip_type]);
- retval = device_create_file(&port->dev, &dev_attr_event_char);
- if ((!retval) &&
- (priv->chip_type == FT232BM ||
- priv->chip_type == FT2232C ||
- priv->chip_type == FT232RL ||
- priv->chip_type == FT2232H ||
- priv->chip_type == FT4232H ||
- priv->chip_type == FT232H ||
- priv->chip_type == FTX)) {
- retval = device_create_file(&port->dev,
- &dev_attr_latency_timer);
- }
- }
- return retval;
-}
-
-static void remove_sysfs_attrs(struct usb_serial_port *port)
-{
- struct ftdi_private *priv = usb_get_serial_port_data(port);
-
- /* XXX see create_sysfs_attrs */
- if (priv->chip_type != SIO) {
- device_remove_file(&port->dev, &dev_attr_event_char);
- if (priv->chip_type == FT232BM ||
- priv->chip_type == FT2232C ||
- priv->chip_type == FT232RL ||
- priv->chip_type == FT2232H ||
- priv->chip_type == FT4232H ||
- priv->chip_type == FT232H ||
- priv->chip_type == FTX) {
- device_remove_file(&port->dev, &dev_attr_latency_timer);
- }
- }
-
-}
-
#ifdef CONFIG_GPIOLIB
static int ftdi_set_bitmode(struct usb_serial_port *port, u8 mode)
@@ -2251,7 +2249,6 @@ static int ftdi_sio_port_probe(struct usb_serial_port *port)
if (read_latency_timer(port) < 0)
priv->latency = 16;
write_latency_timer(port);
- create_sysfs_attrs(port);
result = ftdi_gpio_init(port);
if (result < 0) {
@@ -2377,8 +2374,6 @@ static void ftdi_sio_port_remove(struct usb_serial_port *port)
ftdi_gpio_remove(port);
- remove_sysfs_attrs(port);
-
kfree(priv);
}
--
2.25.1
