2022-09-02 08:30:50

by Jiasheng Jiang

[permalink] [raw]
Subject: [PATCH v2] USB: serial: ftdi_sio: Convert to use dev_groups

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 definition of ftdi_sio_device to the end, remove
create_sysfs_attrs and remove_sysfs_attrs, and convert to use dev_groups.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jiasheng Jiang <[email protected]>
---
Changelog:

v1 -> v2:

1. Change the title.
2. Switch to use an attribute group.
---
drivers/usb/serial/ftdi_sio.c | 124 ++++++++++++----------------------
1 file changed, 42 insertions(+), 82 deletions(-)

diff --git a/drivers/usb/serial/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index d5a3986dfee7..41d8bfb02322 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1108,41 +1108,6 @@ 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);

-static struct usb_serial_driver ftdi_sio_device = {
- .driver = {
- .owner = THIS_MODULE,
- .name = "ftdi_sio",
- },
- .description = "FTDI USB Serial Device",
- .id_table = id_table_combined,
- .num_ports = 1,
- .bulk_in_size = 512,
- .bulk_out_size = 256,
- .probe = ftdi_sio_probe,
- .port_probe = ftdi_sio_port_probe,
- .port_remove = ftdi_sio_port_remove,
- .open = ftdi_open,
- .dtr_rts = ftdi_dtr_rts,
- .throttle = usb_serial_generic_throttle,
- .unthrottle = usb_serial_generic_unthrottle,
- .process_read_urb = ftdi_process_read_urb,
- .prepare_write_buffer = ftdi_prepare_write_buffer,
- .tiocmget = ftdi_tiocmget,
- .tiocmset = ftdi_tiocmset,
- .tiocmiwait = usb_serial_generic_tiocmiwait,
- .get_icount = usb_serial_generic_get_icount,
- .ioctl = ftdi_ioctl,
- .get_serial = get_serial_info,
- .set_serial = set_serial_info,
- .set_termios = ftdi_set_termios,
- .break_ctl = ftdi_break_ctl,
- .tx_empty = ftdi_tx_empty,
-};
-
-static struct usb_serial_driver * const serial_drivers[] = {
- &ftdi_sio_device, NULL
-};
-

#define WDR_TIMEOUT 5000 /* default urb timeout */
#define WDR_SHORT_TIMEOUT 1000 /* shorter urb timeout */
@@ -1729,50 +1694,12 @@ static ssize_t event_char_store(struct device *dev,
}
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);
- }
- }
-
-}
+static struct attribute *ftdi_sio_attrs[] = {
+ &dev_attr_event_char.attr,
+ &dev_attr_latency_timer.attr,
+ NULL,
+};
+ATTRIBUTE_GROUPS(ftdi_sio);

#ifdef CONFIG_GPIOLIB

@@ -2251,7 +2178,6 @@ 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 +2303,6 @@ static void ftdi_sio_port_remove(struct usb_serial_port *port)

ftdi_gpio_remove(port);

- remove_sysfs_attrs(port);
-
kfree(priv);
}

@@ -2915,6 +2839,42 @@ static int ftdi_ioctl(struct tty_struct *tty,
return -ENOIOCTLCMD;
}

+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,
+ .num_ports = 1,
+ .bulk_in_size = 512,
+ .bulk_out_size = 256,
+ .probe = ftdi_sio_probe,
+ .port_probe = ftdi_sio_port_probe,
+ .port_remove = ftdi_sio_port_remove,
+ .open = ftdi_open,
+ .dtr_rts = ftdi_dtr_rts,
+ .throttle = usb_serial_generic_throttle,
+ .unthrottle = usb_serial_generic_unthrottle,
+ .process_read_urb = ftdi_process_read_urb,
+ .prepare_write_buffer = ftdi_prepare_write_buffer,
+ .tiocmget = ftdi_tiocmget,
+ .tiocmset = ftdi_tiocmset,
+ .tiocmiwait = usb_serial_generic_tiocmiwait,
+ .get_icount = usb_serial_generic_get_icount,
+ .ioctl = ftdi_ioctl,
+ .get_serial = get_serial_info,
+ .set_serial = set_serial_info,
+ .set_termios = ftdi_set_termios,
+ .break_ctl = ftdi_break_ctl,
+ .tx_empty = ftdi_tx_empty,
+};
+
+static struct usb_serial_driver * const serial_drivers[] = {
+ &ftdi_sio_device, NULL
+};
+
module_usb_serial_driver(serial_drivers, id_table_combined);

MODULE_AUTHOR(DRIVER_AUTHOR);
--
2.25.1