mpr121_touchkey
struct mpr121_touchkey *mpr121 = dev_id;
static int mpr121_phys_init(struct mpr121_touchkey *mpr121,
struct mpr121_touchkey *mpr121;
struct mpr121_touchkey *mpr121 = i2c_get_clientdata(client);
struct mpr121_touchkey *mpr121 = input_get_drvdata(dev);