IMGU_REG_GP_BUSY
readl(base + IMGU_REG_GP_BUSY);
writel(0, base + IMGU_REG_GP_BUSY);
writel(readl(base + IMGU_REG_GP_BUSY) | 1, base + IMGU_REG_GP_BUSY);
writel(0, base + IMGU_REG_GP_BUSY);
writel(1, base + IMGU_REG_GP_BUSY);
writel(0, base + IMGU_REG_GP_BUSY);
readl(base + IMGU_REG_GP_BUSY);
writel(0, base + IMGU_REG_GP_BUSY);