#define RMI_F03_BYTES_PER_DEVICE_SHIFT 4
 #define RMI_F03_QUEUE_LENGTH           0x0F
 
+#define PSMOUSE_OOB_EXTRA_BTNS         0x01
+
 struct f03_data {
        struct rmi_function *fn;
 
        struct serio *serio;
 
+       unsigned int overwrite_buttons;
+
        u8 device_count;
        u8 rx_queue_length;
 };
 
+int rmi_f03_overwrite_button(struct rmi_function *fn, unsigned int button,
+                            int value)
+{
+       struct f03_data *f03 = dev_get_drvdata(&fn->dev);
+       unsigned int bit;
+
+       if (button < BTN_LEFT || button > BTN_MIDDLE)
+               return -EINVAL;
+
+       bit = BIT(button - BTN_LEFT);
+
+       if (value)
+               f03->overwrite_buttons |= bit;
+       else
+               f03->overwrite_buttons &= ~bit;
+
+       return 0;
+}
+
+void rmi_f03_commit_buttons(struct rmi_function *fn)
+{
+       struct f03_data *f03 = dev_get_drvdata(&fn->dev);
+       struct serio *serio = f03->serio;
+
+       serio_pause_rx(serio);
+       if (serio->drv) {
+               serio->drv->interrupt(serio, PSMOUSE_OOB_EXTRA_BTNS,
+                                     SERIO_OOB_DATA);
+               serio->drv->interrupt(serio, f03->overwrite_buttons,
+                                     SERIO_OOB_DATA);
+       }
+       serio_continue_rx(serio);
+}
+
 static int rmi_f03_pt_write(struct serio *id, unsigned char val)
 {
        struct f03_data *f03 = id->port_data;
 
                                        + 1                             \
                                        + 1)
 
+#define TRACKSTICK_RANGE_START         3
+#define TRACKSTICK_RANGE_END           6
+
 struct rmi_f30_ctrl_data {
        int address;
        int length;
        u16 *gpioled_key_map;
 
        struct input_dev *input;
+
+       struct rmi_function *f03;
+       bool trackstick_buttons;
 };
 
 static int rmi_f30_read_control_parameters(struct rmi_function *fn,
 {
        unsigned int reg_num = button >> 3;
        unsigned int bit_num = button & 0x07;
+       u16 key_code = f30->gpioled_key_map[button];
        bool key_down = !(f30->data_regs[reg_num] & BIT(bit_num));
 
-       rmi_dbg(RMI_DEBUG_FN, &fn->dev,
-               "%s: call input report key (0x%04x) value (0x%02x)",
-               __func__, f30->gpioled_key_map[button], key_down);
+       if (f30->trackstick_buttons &&
+           button >= TRACKSTICK_RANGE_START &&
+           button <= TRACKSTICK_RANGE_END) {
+               rmi_f03_overwrite_button(f30->f03, key_code, key_down);
+       } else {
+               rmi_dbg(RMI_DEBUG_FN, &fn->dev,
+                       "%s: call input report key (0x%04x) value (0x%02x)",
+                       __func__, key_code, key_down);
 
-       input_report_key(f30->input, f30->gpioled_key_map[button], key_down);
+               input_report_key(f30->input, key_code, key_down);
+       }
 }
 
 static int rmi_f30_attention(struct rmi_function *fn, unsigned long *irq_bits)
                }
        }
 
-       if (f30->has_gpio)
+       if (f30->has_gpio) {
                for (i = 0; i < f30->gpioled_count; i++)
                        if (f30->gpioled_key_map[i] != KEY_RESERVED)
                                rmi_f30_report_button(fn, f30, i);
+               if (f30->trackstick_buttons)
+                       rmi_f03_commit_buttons(f30->f03);
+       }
 
        return 0;
 }
                                rmi_get_platform_data(fn->rmi_dev);
        int error;
 
+       if (pdata->f30_data.trackstick_buttons) {
+               /* Try [re-]establish link to F03. */
+               f30->f03 = rmi_find_function(fn->rmi_dev, 0x03);
+               f30->trackstick_buttons = f30->f03 != NULL;
+       }
+
        if (pdata->f30_data.disable) {
                drv->clear_irq_bits(fn->rmi_dev, fn->irq_mask);
        } else {
                                        rmi_get_platform_data(fn->rmi_dev);
        struct input_dev *input = f30->input;
        unsigned int button = BTN_LEFT;
+       unsigned int trackstick_button = BTN_LEFT;
+       bool button_mapped = false;
        int i;
 
        f30->gpioled_key_map = devm_kcalloc(&fn->dev,
        }
 
        for (i = 0; i < f30->gpioled_count; i++) {
-               if (rmi_f30_is_valid_button(i, f30->ctrl)) {
+               if (!rmi_f30_is_valid_button(i, f30->ctrl))
+                       continue;
+
+               if (pdata->f30_data.trackstick_buttons &&
+                   i >= TRACKSTICK_RANGE_START && i < TRACKSTICK_RANGE_END) {
+                       f30->gpioled_key_map[i] = trackstick_button++;
+               } else if (!pdata->f30_data.buttonpad || !button_mapped) {
                        f30->gpioled_key_map[i] = button;
                        input_set_capability(input, EV_KEY, button++);
-
-                       /*
-                        * buttonpad might be given by
-                        * f30->has_mech_mouse_btns, but I am
-                        * not sure, so use only the pdata info
-                        */
-                       if (pdata->f30_data.buttonpad) {
-                               __set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
-                               break;
-                       }
+                       button_mapped = true;
                }
        }
 
        input->keycodesize = sizeof(f30->gpioled_key_map[0]);
        input->keycodemax = f30->gpioled_count;
 
+       /*
+        * Buttonpad could be also inferred from f30->has_mech_mouse_btns,
+        * but I am not sure, so use only the pdata info.
+        */
+       if (pdata->f30_data.buttonpad)
+               __set_bit(INPUT_PROP_BUTTONPAD, input->propbit);
+
        return 0;
 }