HID: lg4ff - Add support for native mode switching

This patch allows the lg4ff driver to switch wheels to the native mode. Since
this is specific to Logitech wheels only, it's handled in hid-lg4ff rather than
hid-lg.
Signed-off-by: Michal Malý <madcatxster@gmail.com>
Signed-off-by: Simon Wood <simon@mungewell.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-lg4ff.c

@@ -31,6 +31,17 @@
 #include "hid-lg.h"
 #include "hid-ids.h"
 
+#define DFGT_REV_MAJ 0x13
+#define DFGT_REV_MIN 0x22
+#define DFP_REV_MAJ 0x11
+#define DFP_REV_MIN 0x06
+#define FFEX_REV_MAJ 0x21
+#define FFEX_REV_MIN 0x00
+#define G25_REV_MAJ 0x12
+#define G25_REV_MIN 0x22
+#define G27_REV_MAJ 0x12
+#define G27_REV_MIN 0x38
+
 static const signed short lg4ff_wheel_effects[] = {
 	FF_CONSTANT,
 	FF_AUTOCENTER,
@@ -55,6 +66,46 @@ static const struct lg4ff_wheel lg4ff_devices[] = {
 	{USB_DEVICE_ID_LOGITECH_WII_WHEEL,   lg4ff_wheel_effects, 40, 270}
 };
 
+struct lg4ff_native_cmd {
+	const __u8 cmd_num;	/* Number of commands to send */
+	const __u8 cmd[];
+};
+
+struct lg4ff_usb_revision {
+	const __u16 rev_maj;
+	const __u16 rev_min;
+	const struct lg4ff_native_cmd *command;
+};
+
+static const struct lg4ff_native_cmd native_dfp = {
+	1,
+	{0xf8, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00}
+};
+
+static const struct lg4ff_native_cmd native_dfgt = {
+	2,
+	{0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 1st command */
+	 0xf8, 0x09, 0x03, 0x01, 0x00, 0x00, 0x00}	/* 2nd command */
+};
+
+static const struct lg4ff_native_cmd native_g25 = {
+	1,
+	{0xf8, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00}
+};
+
+static const struct lg4ff_native_cmd native_g27 = {
+	2,
+	{0xf8, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00,	/* 1st command */
+	 0xf8, 0x09, 0x04, 0x01, 0x00, 0x00, 0x00}	/* 2nd command */
+};
+
+static const struct lg4ff_usb_revision lg4ff_revs[] = {
+	{DFGT_REV_MAJ, DFGT_REV_MIN, &native_dfgt},	/* Driving Force GT */
+	{DFP_REV_MAJ,  DFP_REV_MIN,  &native_dfp},	/* Driving Force Pro */
+	{G25_REV_MAJ,  G25_REV_MIN,  &native_g25},	/* G25 */
+	{G27_REV_MAJ,  G27_REV_MIN,  &native_g27},	/* G27 */
+};
+
 static int hid_lg4ff_play(struct input_dev *dev, void *data,
 			 struct ff_effect *effect)
 {
@@ -100,6 +151,20 @@ static void hid_lg4ff_set_autocenter(struct input_dev *dev, u16 magnitude)
 	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;
+	struct hid_report *report = list_entry(report_list->next, struct hid_report, list);
+	__u8 i, j;
+
+	j = 0;
+	while (j < 7*cmd->cmd_num) {
+		for (i = 0; i < 7; i++)
+			report->field[0]->value[i] = cmd->cmd[j++];
+
+		usbhid_submit_report(hid, report, USB_DIR_OUT);
+	}
+}
 
 int lg4ff_init(struct hid_device *hid)
 {
@@ -108,7 +173,9 @@ 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;
 	int error, i, j;
+	__u16 bcdDevice, rev_maj, rev_min;
 
 	/* Find the report to use */
 	if (list_empty(report_list)) {
@@ -143,6 +210,28 @@ int lg4ff_init(struct hid_device *hid)
 		return -1;
 	}
 
+	/* Attempt to switch wheel to native mode when applicable */
+	udesc = &(hid_to_usb_dev(hid)->descriptor);
+	if (!udesc) {
+		hid_err(hid, "NULL USB device descriptor\n");
+		return -1;
+	}
+	bcdDevice = le16_to_cpu(udesc->bcdDevice);
+	rev_maj = bcdDevice >> 8;
+	rev_min = bcdDevice & 0xff;
+
+	if (lg4ff_devices[i].product_id == USB_DEVICE_ID_LOGITECH_WHEEL) {
+		dbg_hid("Generic wheel detected, can it do native?\n");
+		dbg_hid("USB revision: %2x.%02x\n", rev_maj, rev_min);
+
+		for (j = 0; j < ARRAY_SIZE(lg4ff_revs); j++) {
+			if (lg4ff_revs[j].rev_maj == rev_maj && lg4ff_revs[j].rev_min == rev_min) {
+				hid_lg4ff_switch_native(hid, lg4ff_revs[j].command);
+				hid_info(hid, "Switched to native mode\n");
+			}
+		}
+	}
+
 	/* Set supported force feedback capabilities */
 	for (j = 0; lg4ff_devices[i].ff_effects[j] >= 0; j++)
 		set_bit(lg4ff_devices[i].ff_effects[j], dev->ffbit);