[RFC 4/4] HID:hid-logitech: Add mode control via /sys interface

From: Simon Wood
Date: Thu Aug 21 2014 - 01:01:57 EST


---
drivers/hid/hid-lg4ff.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 78 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
index 0ba0838..1be561e 100644
--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c
@@ -41,11 +41,16 @@ static void hid_lg4ff_set_range_g25(struct hid_device *hid, u16 range);
static ssize_t lg4ff_range_show(struct device *dev, struct device_attribute *attr, char *buf);
static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count);

+static ssize_t lg4ff_mode_show(struct device *dev, struct device_attribute *attr, char *buf);
+static ssize_t lg4ff_mode_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count);
+
static DEVICE_ATTR(range, S_IRWXU | S_IRWXG | S_IROTH, lg4ff_range_show, lg4ff_range_store);
+static DEVICE_ATTR(mode, S_IRWXU | S_IRWXG | S_IROTH, lg4ff_mode_show, lg4ff_mode_store);

struct lg4ff_device_entry {
__u32 product_id;
__u16 type;
+ __u16 mode;
__u16 range;
__u16 min_range;
__u16 max_range;
@@ -362,7 +367,7 @@ static int lg4ff_switch_mode(struct hid_device *hid, __u16 type, int mode)
value[6] = 0x00;

hid_hw_request(hid, report, HID_REQ_SET_REPORT);
- return 0;
+ return LG4FF_MSW_G25;
}

if (mode == LG4FF_MSW_DFP) {
@@ -375,7 +380,7 @@ static int lg4ff_switch_mode(struct hid_device *hid, __u16 type, int mode)
value[6] = 0x00;

hid_hw_request(hid, report, HID_REQ_SET_REPORT);
- return 0;
+ return LG4FF_MSW_DFP;
}

/* Prevent compat mode on USB reset */
@@ -400,7 +405,7 @@ static int lg4ff_switch_mode(struct hid_device *hid, __u16 type, int mode)
value[6] = 0x00;

hid_hw_request(hid, report, HID_REQ_SET_REPORT);
- return 0;
+ return mode;
}

/* Read current range and display it in terminal */
@@ -461,6 +466,66 @@ static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *at
return count;
}

+/* Read current mode and display it in terminal */
+static ssize_t lg4ff_mode_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+ struct hid_device *hid = to_hid_device(dev);
+ struct lg4ff_device_entry *entry;
+ struct lg_drv_data *drv_data;
+ size_t count;
+
+ drv_data = hid_get_drvdata(hid);
+ if (!drv_data) {
+ hid_err(hid, "Private driver data not found!\n");
+ return 0;
+ }
+
+ entry = drv_data->device_props;
+ if (!entry) {
+ hid_err(hid, "Device properties not found!\n");
+ return 0;
+ }
+
+ count = scnprintf(buf, PAGE_SIZE, "%u\n", entry->mode);
+ return count;
+}
+
+/* Set mode to user specified value */
+static ssize_t lg4ff_mode_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
+{
+ struct hid_device *hid = to_hid_device(dev);
+ struct lg4ff_device_entry *entry;
+ struct lg_drv_data *drv_data;
+ int err;
+ __u16 mode = simple_strtoul(buf, NULL, 10);
+
+ drv_data = hid_get_drvdata(hid);
+ if (!drv_data) {
+ hid_err(hid, "Private driver data not found!\n");
+ return -EINVAL;
+ }
+
+ entry = drv_data->device_props;
+ if (!entry) {
+ hid_err(hid, "Device properties not found!\n");
+ return -EINVAL;
+ }
+
+ if (mode == entry->mode) {
+ dbg_hid("Device is already in mode %d\n", mode);
+ return count;
+ }
+
+ err = lg4ff_switch_mode(hid, entry->type, mode);
+ if (err != mode) {
+ hid_err(hid, "Unable to switch mode\n");
+ return -1;
+ }
+
+ entry->mode = mode;
+ return count;
+}
+
#ifdef CONFIG_LEDS_CLASS
static void lg4ff_set_leds(struct hid_device *hid, __u8 leds)
{
@@ -583,6 +648,7 @@ int lg4ff_init(struct hid_device *hid, const int switch_mode)
entry->product_id = hid->product;
entry->set_range = NULL;
entry->type = LG4FF_MSW_EMU;
+ entry->mode = LG4FF_MSW_EMU;

/* Check which wheel has been connected */
bcdDevice = le16_to_cpu(udesc->bcdDevice);
@@ -602,6 +668,11 @@ int lg4ff_init(struct hid_device *hid, const int switch_mode)
entry->min_range = 40;
entry->max_range = 900;
entry->set_range = s->set_range;
+
+ if (switch_mode == LG4FF_MSW_NAT)
+ entry->mode = s->type;
+ else
+ entry->mode = switch_mode;
}

if (hid->product == USB_DEVICE_ID_LOGITECH_WHEEL && switch_mode != LG4FF_MSW_EMU) {
@@ -635,6 +706,9 @@ int lg4ff_init(struct hid_device *hid, const int switch_mode)
error = device_create_file(&hid->dev, &dev_attr_range);
if (error)
return error;
+ error = device_create_file(&hid->dev, &dev_attr_mode);
+ if (error)
+ return error;
dbg_hid("sysfs interface created\n");

/* Set the maximum range to start with */
@@ -705,6 +779,7 @@ int lg4ff_deinit(struct hid_device *hid)
struct lg_drv_data *drv_data;

device_remove_file(&hid->dev, &dev_attr_range);
+ device_remove_file(&hid->dev, &dev_attr_mode);

drv_data = hid_get_drvdata(hid);
if (!drv_data) {
--
1.9.1

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