[RFC PATCH v3.1 19/27] mmc: sdhci-uhs2: add set_reg() to initialise the interface

[AKASHI Takahiro]

This is a sdhci version of mmc's uhs2_set_reg operation.
UHS-II interface (related registers) will be initialised here.

Signed-off-by: Ben Chuang <ben.chuang@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
---
 drivers/mmc/host/sdhci-uhs2.c | 103 ++++++++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)

diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
index 55362ace1857..d8afb99a9918 100644
--- a/drivers/mmc/host/sdhci-uhs2.c
+++ b/drivers/mmc/host/sdhci-uhs2.c
@@ -332,6 +332,68 @@ static void __sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 	spin_unlock_irqrestore(&host->lock, flags);
 }
 
+/* TODO: move this function to sdhci.c */
+static void sdhci_clear_set_irqs(struct sdhci_host *host, u32 clear, u32 set)
+{
+	u32 ier;
+
+	ier = sdhci_readl(host, SDHCI_INT_ENABLE);
+	ier &= ~clear;
+	ier |= set;
+	sdhci_writel(host, ier, SDHCI_INT_ENABLE);
+	sdhci_writel(host, ier, SDHCI_SIGNAL_ENABLE);
+}
+
+static void sdhci_uhs2_set_config(struct sdhci_host *host)
+{
+	u32 value;
+	u16 sdhci_uhs2_set_ptr = sdhci_readw(host, SDHCI_UHS2_SET_PTR);
+	u16 sdhci_uhs2_gen_set_reg = (sdhci_uhs2_set_ptr + 0);
+	u16 sdhci_uhs2_phy_set_reg = (sdhci_uhs2_set_ptr + 4);
+	u16 sdhci_uhs2_tran_set_reg = (sdhci_uhs2_set_ptr + 8);
+	u16 sdhci_uhs2_tran_set_1_reg = (sdhci_uhs2_set_ptr + 12);
+
+	/* Set Gen Settings */
+	sdhci_writel(host, host->mmc->uhs2_caps.n_lanes_set <<
+		SDHCI_UHS2_GEN_SET_N_LANES_POS, sdhci_uhs2_gen_set_reg);
+
+	/* Set PHY Settings */
+	value = (host->mmc->uhs2_caps.n_lss_dir_set <<
+			SDHCI_UHS2_PHY_SET_N_LSS_DIR_POS) |
+		(host->mmc->uhs2_caps.n_lss_sync_set <<
+			SDHCI_UHS2_PHY_SET_N_LSS_SYN_POS);
+	if (host->mmc->flags & MMC_UHS2_SPEED_B)
+		value |= 1 << SDHCI_UHS2_PHY_SET_SPEED_POS;
+	sdhci_writel(host, value, sdhci_uhs2_phy_set_reg);
+
+	/* Set LINK-TRAN Settings */
+	value = (host->mmc->uhs2_caps.max_retry_set <<
+			SDHCI_UHS2_TRAN_SET_RETRY_CNT_POS) |
+		(host->mmc->uhs2_caps.n_fcu_set <<
+			SDHCI_UHS2_TRAN_SET_N_FCU_POS);
+	sdhci_writel(host, value, sdhci_uhs2_tran_set_reg);
+	sdhci_writel(host, host->mmc->uhs2_caps.n_data_gap_set,
+		     sdhci_uhs2_tran_set_1_reg);
+}
+
+static int sdhci_uhs2_check_dormant(struct sdhci_host *host)
+{
+	int timeout = 100;
+
+	while (!(sdhci_readl(host, SDHCI_PRESENT_STATE) &
+		SDHCI_UHS2_IN_DORMANT_STATE)) {
+		if (timeout == 0) {
+			pr_warn("%s: UHS2 IN_DORMANT fail in 100ms.\n",
+				mmc_hostname(host->mmc));
+			sdhci_dumpregs(host);
+			return -EIO;
+		}
+		timeout--;
+		mdelay(1);
+	}
+	return 0;
+}
+
 /*****************************************************************************\
  *                                                                           *
  * MMC callbacks                                                             *
@@ -422,6 +484,45 @@ static void sdhci_uhs2_enable_clk(struct mmc_host *mmc)
 	}
 }
 
+static int sdhci_uhs2_set_reg(struct mmc_host *mmc, enum uhs2_act act)
+{
+        struct sdhci_host *host = mmc_priv(mmc);
+	unsigned long flags;
+	int err = 0;
+	u16 sdhci_uhs2_set_ptr = sdhci_readw(host, SDHCI_UHS2_SET_PTR);
+	u16 sdhci_uhs2_phy_set_reg = (sdhci_uhs2_set_ptr + 4);
+
+	DBG("Begin sdhci_uhs2_set_reg, act %d.\n", act);
+	spin_lock_irqsave(&host->lock, flags);
+
+	switch (act) {
+	case SET_CONFIG:
+		sdhci_uhs2_set_config(host);
+		break;
+	case ENABLE_INT:
+		sdhci_clear_set_irqs(host, 0, SDHCI_INT_CARD_INT);
+		break;
+	case DISABLE_INT:
+		sdhci_clear_set_irqs(host, SDHCI_INT_CARD_INT, 0);
+		break;
+	case SET_SPEED_B:
+		sdhci_writeb(host, 1 << SDHCI_UHS2_PHY_SET_SPEED_POS,
+			     sdhci_uhs2_phy_set_reg);
+		break;
+	case CHECK_DORMANT:
+		err = sdhci_uhs2_check_dormant(host);
+		break;
+	default:
+		pr_err("%s: input action %d is wrong!\n",
+		       mmc_hostname(host->mmc), act);
+		err = -EIO;
+		break;
+	}
+
+	spin_unlock_irqrestore(&host->lock, flags);
+	return err;
+}
+
 /*****************************************************************************\
  *                                                                           *
  * Driver init/exit                                                          *
@@ -597,6 +698,8 @@ static int sdhci_uhs2_host_ops_init(struct sdhci_host *host)
 		host->mmc_host_ops.uhs2_disable_clk = sdhci_uhs2_disable_clk;
 	if (!host->mmc_host_ops.uhs2_enable_clk)
 		host->mmc_host_ops.uhs2_enable_clk = sdhci_uhs2_enable_clk;
+	if (!host->mmc_host_ops.uhs2_set_reg)
+		host->mmc_host_ops.uhs2_set_reg = sdhci_uhs2_set_reg;
 
 	return 0;
 }
-- 
2.28.0