mmc: sunxi: Always set signal delay to 0 for A64

static int sunxi_mmc_calibrate(struct sunxi_mmc_host *host, int reg_off)

{

	u32 reg = readl(host->reg_base + reg_off);

	u32 delay;

	unsigned long timeout;

	if (!host->cfg->can_calibrate)

		return 0;

	reg &= ~(SDXC_CAL_DL_MASK << SDXC_CAL_DL_SW_SHIFT);

	reg &= ~SDXC_CAL_DL_SW_EN;

	writel(reg | SDXC_CAL_START, host->reg_base + reg_off);

	dev_dbg(mmc_dev(host->mmc), "calibration started\n");

	timeout = jiffies + HZ * SDXC_CAL_TIMEOUT;

	while (!((reg = readl(host->reg_base + reg_off)) & SDXC_CAL_DONE)) {

		if (time_before(jiffies, timeout))

			cpu_relax();

		else {

			reg &= ~SDXC_CAL_START;

			writel(reg, host->reg_base + reg_off);

			return -ETIMEDOUT;

		}

	}

	delay = (reg >> SDXC_CAL_DL_SHIFT) & SDXC_CAL_DL_MASK;

	reg &= ~SDXC_CAL_START;

	reg |= (delay << SDXC_CAL_DL_SW_SHIFT) | SDXC_CAL_DL_SW_EN;

	writel(reg, host->reg_base + reg_off);

	dev_dbg(mmc_dev(host->mmc), "calibration ended, reg is 0x%x\n", reg);

	/*

	 * FIXME:

	 * This is not clear how the calibration is supposed to work

	 * yet. The best rate have been obtained by simply setting the

	 * delay to 0, as Allwinner does in its BSP.

	 *

	 * The only mode that doesn't have such a delay is HS400, that

	 * is in itself a TODO.

	 */

	writel(SDXC_CAL_DL_SW_EN, host->reg_base + reg_off);

	return 0;

}

	if (ret)

		return ret;

	/* TODO: enable calibrate on sdc2 SDXC_REG_DS_DL_REG of A64 */

	/*

	 * FIXME:

	 *

	 * In HS400 we'll also need to calibrate the data strobe

	 * signal. This should only happen on the MMC2 controller (at

	 * least on the A64).

	 */

	return sunxi_mmc_oclk_onoff(host, 1);

}