[PATCH] hid: split picolcd's operation_mode sysfs attribute

Bruno Prémont
2010-04-25T20:16:33Z

Original operation_mode sysfs attribute accepts the operation mode
as main value with an option delay as second value to change
the start-up delay on mode change.

As it is preferred to have exactly one value per sysfs attribute,
extract this delay into a separate sysfs attribute called
operation_mode_delay.

Signed-off-by: Bruno Prémont <bonbons@linux-vserver.org>
---
Documentation/ABI/testing/sysfs-driver-hid-picolcd | 17 ++++-
drivers/hid/hid-picolcd.c | 62 ++++++++++++++-----
2 files changed, 58 insertions(+), 21 deletions(-)

diff --git a/Documentation/ABI/testing/sysfs-driver-hid-picolcd b/Documentation/ABI/testing/sysfs-driver-hid-picolcd
index 14f52d7..08579e7 100644
--- a/Documentation/ABI/testing/sysfs-driver-hid-picolcd
+++ b/Documentation/ABI/testing/sysfs-driver-hid-picolcd
@@ -8,12 +8,21 @@ Description: Make it possible to switch the PicoLCD device between LCD
enclosed in brackets ('[' and ']')

Writing: causes operation mode switch. Permitted values are
- the non-active mode names listed when read, optionally followed
- by a delay value expressed in ms.
+ the non-active mode names listed when read.

Note: when switching mode the current PicoLCD HID device gets
- disconnected and reconnects after above delay (default value
- is 5 seconds though this default should not be relied on).
+ disconnected and reconnects after above delay (see attribute
+ operation_mode_delay for its value).
+
+
+What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/operation_mode_delay
+Date: April 2010
+Contact: Bruno Prémont <bonbons@linux-vserver.org>
+Description: Delay PicoLCD waits before restarting in new mode when
+ operation_mode has changed.
+
+ Reading/Writing: It is expressed in ms and permitted range is
+ 0..30000ms.

What: /sys/bus/usb/devices/<busnum>-<devnum>:<config num>.<interface num>/<hid-bus>:<vendor-id>:<product-id>.<num>/fb_update_rate
diff --git a/drivers/hid/hid-picolcd.c b/drivers/hid/hid-picolcd.c
index 6f71c60..aa6f2e1 100644
--- a/drivers/hid/hid-picolcd.c
+++ b/drivers/hid/hid-picolcd.c
@@ -177,6 +177,7 @@ struct picolcd_data {
int addr_sz;
#endif
u8 version[2];
+ unsigned short opmode_delay;
/* input stuff */
u8 pressed_keys[2];
struct input_dev *input_keys;
@@ -1270,8 +1271,7 @@ static ssize_t picolcd_operation_mode_store(struct device *dev,
struct picolcd_data *data = dev_get_drvdata(dev);
struct hid_report *report = NULL;
size_t cnt = count;
- int timeout = 5000;
- unsigned u;
+ int timeout = data->opmode_delay;
unsigned long flags;

if (cnt >= 3 && strncmp("lcd", buf, 3) == 0) {
@@ -1288,20 +1288,10 @@ static ssize_t picolcd_operation_mode_store(struct device *dev,
if (!report)
return -EINVAL;

- while (cnt > 0 && (*buf == ' ' || *buf == '\t')) {
- buf++;
- cnt--;
- }
while (cnt > 0 && (buf[cnt-1] == '\n' || buf[cnt-1] == '\r'))
cnt--;
- if (cnt > 0) {
- if (sscanf(buf, "%u", &u) != 1)
- return -EINVAL;
- if (u > 30000)
- return -EINVAL;
- else
- timeout = u;
- }
+ if (cnt != 0)
+ return -EINVAL;

spin_lock_irqsave(&data->lock, flags);
hid_set_field(report->field[0], 0, timeout & 0xff);
@@ -1314,6 +1304,34 @@ static ssize_t picolcd_operation_mode_store(struct device *dev,
static DEVICE_ATTR(operation_mode, 0644, picolcd_operation_mode_show,
picolcd_operation_mode_store);

+/*
+ * The "operation_mode_delay" sysfs attribute
+ */
+static ssize_t picolcd_operation_mode_delay_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct picolcd_data *data = dev_get_drvdata(dev);
+
+ return snprintf(buf, PAGE_SIZE, "%hu\n", data->opmode_delay);
+}
+
+static ssize_t picolcd_operation_mode_delay_store(struct device *dev,
+ struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct picolcd_data *data = dev_get_drvdata(dev);
+ unsigned u;
+ if (sscanf(buf, "%u", &u) != 1)
+ return -EINVAL;
+ if (u > 30000)
+ return -EINVAL;
+ else
+ data->opmode_delay = u;
+ return count;
+}
+
+static DEVICE_ATTR(operation_mode_delay, 0644, picolcd_operation_mode_delay_show,
+ picolcd_operation_mode_delay_store);
+

#ifdef CONFIG_DEBUG_FS
/*
@@ -2409,6 +2427,7 @@ static int picolcd_probe(struct hid_device *hdev,
spin_lock_init(&data->lock);
mutex_init(&data->mutex);
data->hdev = hdev;
+ data->opmode_delay = 5000;
if (hdev->product == USB_DEVICE_ID_PICOLCD_BOOTLOADER)
data->status |= PICOLCD_BOOTLOADER;
hid_set_drvdata(hdev, data);
@@ -2436,24 +2455,32 @@ static int picolcd_probe(struct hid_device *hdev,
goto err_cleanup_hid_hw;
}

- error = device_create_file(&hdev->dev, &dev_attr_operation_mode);
+ error = device_create_file(&hdev->dev, &dev_attr_operation_mode_delay);
if (error) {
dev_err(&hdev->dev, "failed to create sysfs attributes\n");
goto err_cleanup_hid_ll;
}

+ error = device_create_file(&hdev->dev, &dev_attr_operation_mode);
+ if (error) {
+ dev_err(&hdev->dev, "failed to create sysfs attributes\n");
+ goto err_cleanup_sysfs1;
+ }
+
if (data->status & PICOLCD_BOOTLOADER)
error = picolcd_probe_bootloader(hdev, data);
else
error = picolcd_probe_lcd(hdev, data);
if (error)
- goto err_cleanup_sysfs;
+ goto err_cleanup_sysfs2;

dbg_hid(PICOLCD_NAME " activated and initialized\n");
return 0;

-err_cleanup_sysfs:
+err_cleanup_sysfs2:
device_remove_file(&hdev->dev, &dev_attr_operation_mode);
+err_cleanup_sysfs1:
+ device_remove_file(&hdev->dev, &dev_attr_operation_mode_delay);
err_cleanup_hid_ll:
hdev->ll_driver->close(hdev);
err_cleanup_hid_hw:
@@ -2478,6 +2505,7 @@ static void picolcd_remove(struct hid_device *hdev)

picolcd_exit_devfs(data);
device_remove_file(&hdev->dev, &dev_attr_operation_mode);
+ device_remove_file(&hdev->dev, &dev_attr_operation_mode_delay);
hdev->ll_driver->close(hdev);
hid_hw_stop(hdev);
hid_set_drvdata(hdev, NULL);
--
1.6.4.4