[RFC PATCH v3.1 17/27] mmc: sdhci-uhs2: add detect_init() to detect the interface

[AKASHI Takahiro]

Sdhci_uhs2_do_detect_init() is a sdhci version of mmc's uhs2_detect_init
operation. After detected, the host's UHS-II capabilities will be set up
here and interrupts will also be enabled.

Signed-off-by: Ben Chuang <ben.chuang@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
---
 drivers/mmc/host/sdhci-uhs2.c | 160 ++++++++++++++++++++++++++++++++++
 1 file changed, 160 insertions(+)

diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
index 637464748cc4..994dff967e85 100644
--- a/drivers/mmc/host/sdhci-uhs2.c
+++ b/drivers/mmc/host/sdhci-uhs2.c
@@ -391,12 +391,172 @@ void sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
  *                                                                           *
 \*****************************************************************************/
 
+static int sdhci_uhs2_interface_detect(struct sdhci_host *host)
+{
+	int timeout = 100;
+
+	udelay(200); /* wait for 200us before check */
+
+	while (!(sdhci_readl(host, SDHCI_PRESENT_STATE) &
+		SDHCI_UHS2_IF_DETECT)) {
+		if (timeout == 0) {
+			pr_warn("%s: not detect UHS2 interface in 200us.\n",
+				mmc_hostname(host->mmc));
+			sdhci_dumpregs(host);
+			return -EIO;
+		}
+		timeout--;
+		mdelay(1);
+	}
+
+	/* Enable UHS2 error interrupts */
+	sdhci_uhs2_clear_set_irqs(host, SDHCI_INT_ALL_MASK,
+				  SDHCI_UHS2_ERR_INT_STATUS_MASK);
+
+	timeout = 150;
+	while (!(sdhci_readl(host, SDHCI_PRESENT_STATE) &
+		SDHCI_UHS2_LANE_SYNC)) {
+		if (timeout == 0) {
+			pr_warn("%s: UHS2 Lane sync fail in 150ms.\n",
+				mmc_hostname(host->mmc));
+			sdhci_dumpregs(host);
+			return -EIO;
+		}
+		timeout--;
+		mdelay(1);
+	}
+
+	DBG("%s: UHS2 Lane synchronized in UHS2 mode, PHY is initialized.\n",
+	    mmc_hostname(host->mmc));
+	return 0;
+}
+
+static int sdhci_uhs2_init(struct sdhci_host *host)
+{
+	u16 caps_ptr = 0;
+	u32 caps_gen = 0;
+	u32 caps_phy = 0;
+	u32 caps_tran[2] = {0, 0};
+	struct mmc_host *mmc = host->mmc;
+
+	/*
+	 * TODO: may add corresponding members in sdhci_host to
+	 * keep these caps.
+	 */
+	caps_ptr = sdhci_readw(host, SDHCI_UHS2_HOST_CAPS_PTR);
+	if (caps_ptr < 0x100 || caps_ptr > 0x1FF) {
+		pr_err("%s: SDHCI_UHS2_HOST_CAPS_PTR(%d) is wrong.\n",
+		       mmc_hostname(mmc), caps_ptr);
+		return -ENODEV;
+	}
+	caps_gen = sdhci_readl(host,
+			       caps_ptr + SDHCI_UHS2_HOST_CAPS_GEN_OFFSET);
+	caps_phy = sdhci_readl(host,
+			       caps_ptr + SDHCI_UHS2_HOST_CAPS_PHY_OFFSET);
+	caps_tran[0] = sdhci_readl(host,
+				   caps_ptr + SDHCI_UHS2_HOST_CAPS_TRAN_OFFSET);
+	caps_tran[1] = sdhci_readl(host,
+				   caps_ptr
+					+ SDHCI_UHS2_HOST_CAPS_TRAN_1_OFFSET);
+
+	/* General Caps */
+	mmc->uhs2_caps.dap = caps_gen & SDHCI_UHS2_HOST_CAPS_GEN_DAP_MASK;
+	mmc->uhs2_caps.gap = (caps_gen & SDHCI_UHS2_HOST_CAPS_GEN_GAP_MASK) >>
+			     SDHCI_UHS2_HOST_CAPS_GEN_GAP_SHIFT;
+	mmc->uhs2_caps.n_lanes = (caps_gen & SDHCI_UHS2_HOST_CAPS_GEN_LANE_MASK)
+			>> SDHCI_UHS2_HOST_CAPS_GEN_LANE_SHIFT;
+	mmc->uhs2_caps.addr64 =
+		(caps_gen & SDHCI_UHS2_HOST_CAPS_GEN_ADDR_64) ? 1 : 0;
+	mmc->uhs2_caps.card_type =
+		(caps_gen & SDHCI_UHS2_HOST_CAPS_GEN_DEV_TYPE_MASK) >>
+		SDHCI_UHS2_HOST_CAPS_GEN_DEV_TYPE_SHIFT;
+
+	/* PHY Caps */
+	mmc->uhs2_caps.phy_rev = caps_phy & SDHCI_UHS2_HOST_CAPS_PHY_REV_MASK;
+	mmc->uhs2_caps.speed_range =
+		(caps_phy & SDHCI_UHS2_HOST_CAPS_PHY_RANGE_MASK)
+		>> SDHCI_UHS2_HOST_CAPS_PHY_RANGE_SHIFT;
+	mmc->uhs2_caps.n_lss_sync =
+		(caps_phy & SDHCI_UHS2_HOST_CAPS_PHY_N_LSS_SYN_MASK)
+		>> SDHCI_UHS2_HOST_CAPS_PHY_N_LSS_SYN_SHIFT;
+	mmc->uhs2_caps.n_lss_dir =
+		(caps_phy & SDHCI_UHS2_HOST_CAPS_PHY_N_LSS_DIR_MASK)
+		>> SDHCI_UHS2_HOST_CAPS_PHY_N_LSS_DIR_SHIFT;
+	if (mmc->uhs2_caps.n_lss_sync == 0)
+		mmc->uhs2_caps.n_lss_sync = 16 << 2;
+	else
+		mmc->uhs2_caps.n_lss_sync <<= 2;
+	if (mmc->uhs2_caps.n_lss_dir == 0)
+		mmc->uhs2_caps.n_lss_dir = 16 << 3;
+	else
+		mmc->uhs2_caps.n_lss_dir <<= 3;
+
+	/* LINK/TRAN Caps */
+	mmc->uhs2_caps.link_rev =
+		caps_tran[0] & SDHCI_UHS2_HOST_CAPS_TRAN_LINK_REV_MASK;
+	mmc->uhs2_caps.n_fcu =
+		(caps_tran[0] & SDHCI_UHS2_HOST_CAPS_TRAN_N_FCU_MASK)
+		>> SDHCI_UHS2_HOST_CAPS_TRAN_N_FCU_SHIFT;
+	if (mmc->uhs2_caps.n_fcu == 0)
+		mmc->uhs2_caps.n_fcu = 256;
+	mmc->uhs2_caps.host_type =
+		(caps_tran[0] & SDHCI_UHS2_HOST_CAPS_TRAN_HOST_TYPE_MASK)
+		>> SDHCI_UHS2_HOST_CAPS_TRAN_HOST_TYPE_SHIFT;
+	mmc->uhs2_caps.maxblk_len =
+		(caps_tran[0] & SDHCI_UHS2_HOST_CAPS_TRAN_BLK_LEN_MASK)
+		>> SDHCI_UHS2_HOST_CAPS_TRAN_BLK_LEN_SHIFT;
+	mmc->uhs2_caps.n_data_gap =
+		caps_tran[1] & SDHCI_UHS2_HOST_CAPS_TRAN_1_N_DATA_GAP_MASK;
+
+	return 0;
+}
+
+static int sdhci_uhs2_do_detect_init(struct mmc_host *mmc)
+{
+        struct sdhci_host *host = mmc_priv(mmc);
+	unsigned long flags;
+	int ret = -EIO;
+
+	DBG("%s: begin UHS2 init.\n", __func__);
+	spin_lock_irqsave(&host->lock, flags);
+
+	if (sdhci_uhs2_interface_detect(host)) {
+		pr_warn("%s: cannot detect UHS2 interface.\n",
+			mmc_hostname(host->mmc));
+		goto out;
+	}
+
+	if (sdhci_uhs2_init(host)) {
+		pr_warn("%s: UHS2 init fail.\n", mmc_hostname(host->mmc));
+		goto out;
+	}
+
+	/* Init complete, do soft reset and enable UHS2 error irqs. */
+	sdhci_uhs2_reset(host, SDHCI_UHS2_SW_RESET_SD);
+	sdhci_uhs2_clear_set_irqs(host, SDHCI_INT_ALL_MASK,
+				  SDHCI_UHS2_ERR_INT_STATUS_MASK);
+	/*
+	 * !!! SDHCI_INT_ENABLE and SDHCI_SIGNAL_ENABLE was cleared
+	 * by SDHCI_UHS2_SW_RESET_SD
+	 */
+	sdhci_writel(host, host->ier, SDHCI_INT_ENABLE);
+	sdhci_writel(host, host->ier, SDHCI_SIGNAL_ENABLE);
+
+	ret = 0;
+out:
+	spin_unlock_irqrestore(&host->lock, flags);
+	return ret;
+}
+
 static int sdhci_uhs2_host_ops_init(struct sdhci_host *host)
 {
 	host->mmc_host_ops.start_signal_voltage_switch =
 		sdhci_uhs2_start_signal_voltage_switch;
 	host->mmc_host_ops.set_ios = sdhci_uhs2_set_ios;
 
+	if (!host->mmc_host_ops.uhs2_detect_init)
+		host->mmc_host_ops.uhs2_detect_init = sdhci_uhs2_do_detect_init;
+
 	return 0;
 }
 
-- 
2.28.0