HID: lg4ff - Add range setting support and sysfs interface

Wheel range of certain Logitech wheels - namely Driving Force GT, Driving Force
Pro, G25 and G27 can be adjusted. Minimu is 40 degrees, maximum 900. DFGT, G25
and G27 all use a common command, DFP uses another one.  Range can be set from
userspace by writing to
"/sys/module/hid_logitech/drivers/hid:logitech/<dev>range". The driver use list
to store range of each connected wheel; it's not possible to use driver_data in
hid_device struct as it's already b hig-lg driver.

Signed-off-by: Michal Malý <madcatxster@gmail.com>
Signed-off-by: Simon Wood <simon@mungewell.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

1 files changed, 220 insertions, 12 deletions

diff --git a/drivers/hid/hid-lg4ff.c b/drivers/hid/hid-lg4ff.c
index 8eb938d7aa02..5c9eef2267ed 100644
--- a/drivers/hid/hid-lg4ff.c
+++ b/drivers/hid/hid-lg4ff.c
@@ -42,6 +42,29 @@
 #define G27_REV_MAJ 0x12
 #define G27_REV_MIN 0x38
 
+#define to_hid_device(pdev) container_of(pdev, struct hid_device, dev)
+
+static void hid_lg4ff_set_range_dfp(struct hid_device *hid, u16 range);
+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 DEVICE_ATTR(range, S_IRWXU | S_IRWXG | S_IRWXO, lg4ff_range_show, lg4ff_range_store);
+
+static bool list_inited;
+
+struct lg4ff_device_entry {
+        char  *device_id;       /* Use name in respective kobject structure's address as the ID */
+        __u16 range;
+        __u16 min_range;
+        __u16 max_range;
+        __u8  leds;
+        struct list_head list;
+        void (*set_range)(struct hid_device *hid, u16 range);
+};
+
+static struct lg4ff_device_entry device_list;
+
 static const signed short lg4ff_wheel_effects[] = {
         FF_CONSTANT,
         FF_AUTOCENTER,
@@ -53,17 +76,18 @@ struct lg4ff_wheel {
         const signed short *ff_effects;
         const __u16 min_range;
         const __u16 max_range;
+        void (*set_range)(struct hid_device *hid, u16 range);
 };
 
 static const struct lg4ff_wheel lg4ff_devices[] = {
-        {USB_DEVICE_ID_LOGITECH_WHEEL,       lg4ff_wheel_effects, 40, 270},
-        {USB_DEVICE_ID_LOGITECH_MOMO_WHEEL,  lg4ff_wheel_effects, 40, 270},
-        {USB_DEVICE_ID_LOGITECH_DFP_WHEEL,   lg4ff_wheel_effects, 40, 900},
-        {USB_DEVICE_ID_LOGITECH_G25_WHEEL,   lg4ff_wheel_effects, 40, 900},
-        {USB_DEVICE_ID_LOGITECH_DFGT_WHEEL,  lg4ff_wheel_effects, 40, 900},
-        {USB_DEVICE_ID_LOGITECH_G27_WHEEL,   lg4ff_wheel_effects, 40, 900},
-        {USB_DEVICE_ID_LOGITECH_MOMO_WHEEL2, lg4ff_wheel_effects, 40, 270},
-        {USB_DEVICE_ID_LOGITECH_WII_WHEEL,   lg4ff_wheel_effects, 40, 270}
+        {USB_DEVICE_ID_LOGITECH_WHEEL,       lg4ff_wheel_effects, 40, 270, NULL},
+        {USB_DEVICE_ID_LOGITECH_MOMO_WHEEL,  lg4ff_wheel_effects, 40, 270, NULL},
+        {USB_DEVICE_ID_LOGITECH_DFP_WHEEL,   lg4ff_wheel_effects, 40, 900, hid_lg4ff_set_range_dfp},
+        {USB_DEVICE_ID_LOGITECH_G25_WHEEL,   lg4ff_wheel_effects, 40, 900, hid_lg4ff_set_range_g25},
+        {USB_DEVICE_ID_LOGITECH_DFGT_WHEEL,  lg4ff_wheel_effects, 40, 900, hid_lg4ff_set_range_g25},
+        {USB_DEVICE_ID_LOGITECH_G27_WHEEL,   lg4ff_wheel_effects, 40, 900, hid_lg4ff_set_range_g25},
+        {USB_DEVICE_ID_LOGITECH_MOMO_WHEEL2, lg4ff_wheel_effects, 40, 270, NULL},
+        {USB_DEVICE_ID_LOGITECH_WII_WHEEL,   lg4ff_wheel_effects, 40, 270, NULL}
 };
 
 struct lg4ff_native_cmd {
@@ -106,8 +130,7 @@ static const struct lg4ff_usb_revision lg4ff_revs[] = {
         {G27_REV_MAJ,  G27_REV_MIN,  &native_g27},      /* G27 */
 };
 
-static int hid_lg4ff_play(struct input_dev *dev, void *data,
-                         struct ff_effect *effect)
+static int hid_lg4ff_play(struct input_dev *dev, void *data, struct ff_effect *effect)
 {
         struct hid_device *hid = input_get_drvdata(dev);
         struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
@@ -151,6 +174,77 @@ static void hid_lg4ff_set_autocenter(struct input_dev *dev, u16 magnitude)
         usbhid_submit_report(hid, report, USB_DIR_OUT);
 }
 
+/* Sends command to set range compatible with G25/G27/Driving Force GT */
+static void hid_lg4ff_set_range_g25(struct hid_device *hid, u16 range)
+{
+        struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
+        struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
+        dbg_hid("G25/G27/DFGT: setting range to %u\n", range);
+
+        report->field[0]->value[0] = 0xf8;
+        report->field[0]->value[1] = 0x81;
+        report->field[0]->value[2] = range & 0x00ff;
+        report->field[0]->value[3] = (range & 0xff00) >> 8;
+        report->field[0]->value[4] = 0x00;
+        report->field[0]->value[5] = 0x00;
+        report->field[0]->value[6] = 0x00;
+
+        usbhid_submit_report(hid, report, USB_DIR_OUT);
+}
+
+/* Sends commands to set range compatible with Driving Force Pro wheel */
+static void hid_lg4ff_set_range_dfp(struct hid_device *hid, __u16 range)
+{
+        struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
+        struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
+        int start_left, start_right, full_range;
+        dbg_hid("Driving Force Pro: setting range to %u\n", range);
+
+        /* Prepare "coarse" limit command */
+        report->field[0]->value[0] = 0xf8;
+        report->field[0]->value[1] = 0x00;      /* Set later */
+        report->field[0]->value[2] = 0x00;
+        report->field[0]->value[3] = 0x00;
+        report->field[0]->value[4] = 0x00;
+        report->field[0]->value[5] = 0x00;
+        report->field[0]->value[6] = 0x00;
+
+        if (range > 200) {
+                report->field[0]->value[1] = 0x03;
+                full_range = 900;
+        } else {
+                report->field[0]->value[1] = 0x02;
+                full_range = 200;
+        }
+        usbhid_submit_report(hid, report, USB_DIR_OUT);
+
+        /* Prepare "fine" limit command */
+        report->field[0]->value[0] = 0x81;
+        report->field[0]->value[1] = 0x0b;
+        report->field[0]->value[2] = 0x00;
+        report->field[0]->value[3] = 0x00;
+        report->field[0]->value[4] = 0x00;
+        report->field[0]->value[5] = 0x00;
+        report->field[0]->value[6] = 0x00;
+
+        if (range == 200 || range == 900) {     /* Do not apply any fine limit */
+                usbhid_submit_report(hid, report, USB_DIR_OUT);
+                return;
+        }
+
+        /* Construct fine limit command */
+        start_left = (((full_range - range + 1) * 2047) / full_range);
+        start_right = 0xfff - start_left;
+
+        report->field[0]->value[2] = start_left >> 4;
+        report->field[0]->value[3] = start_right >> 4;
+        report->field[0]->value[4] = 0xff;
+        report->field[0]->value[5] = (start_right & 0xe) << 4 | (start_left & 0xe);
+        report->field[0]->value[6] = 0xff;
+
+        usbhid_submit_report(hid, report, USB_DIR_OUT);
+}
+
 static void hid_lg4ff_switch_native(struct hid_device *hid, const struct lg4ff_native_cmd *cmd)
 {
         struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
@@ -166,6 +260,60 @@ static void hid_lg4ff_switch_native(struct hid_device *hid, const struct lg4ff_n
         }
 }
 
+/* Read current range and display it in terminal */
+static ssize_t lg4ff_range_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+        struct lg4ff_device_entry *entry = 0;
+        struct list_head *h;
+        struct hid_device *hid = to_hid_device(dev);
+        size_t count;
+
+        list_for_each(h, &device_list.list) {
+                entry = list_entry(h, struct lg4ff_device_entry, list);
+                if (strcmp(entry->device_id, (&hid->dev)->kobj.name) == 0)
+                        break;
+        }
+        if (h == &device_list.list) {
+                dbg_hid("Device not found!");
+                return 0;
+        }
+
+        count = scnprintf(buf, PAGE_SIZE, "%u\n", entry->range);
+        return count;
+}
+
+/* Set range to user specified value, call appropriate function
+ * according to the type of the wheel */
+static ssize_t lg4ff_range_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
+{
+        struct lg4ff_device_entry *entry = 0;
+        struct list_head *h;
+        struct hid_device *hid = to_hid_device(dev);
+        __u16 range = simple_strtoul(buf, NULL, 10);
+
+        list_for_each(h, &device_list.list) {
+                entry = list_entry(h, struct lg4ff_device_entry, list);
+                if (strcmp(entry->device_id, (&hid->dev)->kobj.name) == 0)
+                        break;
+        }
+        if (h == &device_list.list) {
+                dbg_hid("Device not found!");
+                return count;
+        }
+
+        if (range == 0)
+                range = entry->max_range;
+
+        /* Check if the wheel supports range setting
+         * and that the range is within limits for the wheel */
+        if (entry->set_range != NULL && range >= entry->min_range && range <= entry->max_range) {
+                entry->set_range(hid, range);
+                entry->range = range;
+        }
+
+        return count;
+}
+
 int lg4ff_init(struct hid_device *hid)
 {
         struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
@@ -173,7 +321,8 @@ int lg4ff_init(struct hid_device *hid)
         struct input_dev *dev = hidinput->input;
         struct hid_report *report;
         struct hid_field *field;
-        struct usb_device_descriptor *udesc = 0;
+        struct lg4ff_device_entry *entry;
+        struct usb_device_descriptor *udesc;
         int error, i, j;
         __u16 bcdDevice, rev_maj, rev_min;
 
@@ -195,7 +344,7 @@ int lg4ff_init(struct hid_device *hid)
                 hid_err(hid, "NULL field\n");
                 return -1;
         }
-        
+
         /* Check what wheel has been connected */
         for (i = 0; i < ARRAY_SIZE(lg4ff_devices); i++) {
                 if (hid->product == lg4ff_devices[i].product_id) {
@@ -244,7 +393,66 @@ int lg4ff_init(struct hid_device *hid)
         if (test_bit(FF_AUTOCENTER, dev->ffbit))
                 dev->ff->set_autocenter = hid_lg4ff_set_autocenter;
 
+                /* Initialize device_list if this is the first device to handle by lg4ff */
+        if (!list_inited) {
+                INIT_LIST_HEAD(&device_list.list);
+                list_inited = 1;
+        }
+
+        /* Add the device to device_list */
+        entry = (struct lg4ff_device_entry *)kzalloc(sizeof(struct lg4ff_device_entry), GFP_KERNEL);
+        if (!entry) {
+                hid_err(hid, "Cannot add device, insufficient memory.\n");
+                return -ENOMEM;
+        }
+        entry->device_id = (char *)kzalloc(strlen((&hid->dev)->kobj.name) + 1, GFP_KERNEL);
+        if (!entry->device_id) {
+                hid_err(hid, "Cannot set device_id, insufficient memory.\n");
+                return -ENOMEM;
+        }
+        strcpy(entry->device_id, (&hid->dev)->kobj.name);
+        entry->min_range = lg4ff_devices[i].min_range;
+        entry->max_range = lg4ff_devices[i].max_range;
+        entry->set_range = lg4ff_devices[i].set_range;
+        list_add(&entry->list, &device_list.list);
+
+        /* Create sysfs interface */
+        error = device_create_file(&hid->dev, &dev_attr_range);
+        if (error)
+                return error;
+        dbg_hid("sysfs interface created\n");
+
+        /* Set the maximum range to start with */
+        entry->range = entry->max_range;
+        if (entry->set_range != NULL)
+                entry->set_range(hid, entry->range);
+
         hid_info(hid, "Force feedback for Logitech Speed Force Wireless by Simon Wood <simon@mungewell.org>\n");
         return 0;
 }
 
+int lg4ff_deinit(struct hid_device *hid)
+{
+        bool found = 0;
+        struct lg4ff_device_entry *entry;
+        struct list_head *h, *g;
+        list_for_each_safe(h, g, &device_list.list) {
+                entry = list_entry(h, struct lg4ff_device_entry, list);
+                if (strcmp(entry->device_id, (&hid->dev)->kobj.name) == 0) {
+                        list_del(h);
+                        kfree(entry->device_id);
+                        kfree(entry);
+                        found = 1;
+                        break;
+                }
+        }
+
+        if (!found) {
+                dbg_hid("Device entry not found!\n");
+                return -1;
+        }
+
+        device_remove_file(&hid->dev, &dev_attr_range);
+        dbg_hid("Device successfully unregistered\n");
+        return 0;
+}