[PATCH V20 15/22] mmc: sdhci-uhs2: add uhs2_control() to initialise the interface

[Victor Shih <victorshihgli@gmail.com>]

From: Victor Shih <victor.shih@genesyslogic.com.tw>

UHS-II interface (related registers) will be initialized here. The operations include mmc's
uhs2_set_reg operations, mmc's uhs2_detect_init operations, uhs2_[enable|disable]_clk operations,
uhs2_set_ios operations. After detected the UHS-II interface, the host's UHS-II capabilities will
be set up here and interrupts will also be enabled.

Signed-off-by: Ben Chuang <ben.chuang@genesyslogic.com.tw>
Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Victor Shih <victor.shih@genesyslogic.com.tw>
---

Updates in V15:
 - Resolve merge conflicts and reduce unnecessary line breaks.

Updates in V13:
 - Merge Patch#15, Patch#16 and Patch#17 of v12 version into Patch#15 in v13 version.
 - Use definitions to simplify code.
 - Modify comment message.

---

 drivers/mmc/host/sdhci-uhs2.c | 228 ++++++++++++++++++++++++++++++++++
 1 file changed, 228 insertions(+)

diff --git a/drivers/mmc/host/sdhci-uhs2.c b/drivers/mmc/host/sdhci-uhs2.c
index abb56ab8f916..a521e3dbfca7 100644
--- a/drivers/mmc/host/sdhci-uhs2.c
+++ b/drivers/mmc/host/sdhci-uhs2.c
@@ -25,6 +25,9 @@
 	pr_err("%s: " DRIVER_NAME ": " f, mmc_hostname(host->mmc), ## x)
 
 #define UHS2_RESET_TIMEOUT_100MS		100000
+#define UHS2_CHECK_DORMANT_TIMEOUT_100MS	100000
+#define UHS2_INTERFACE_DETECT_TIMEOUT_100MS	100000
+#define UHS2_LANE_SYNC_TIMEOUT_150MS		150000
 
 void sdhci_uhs2_dump_regs(struct sdhci_host *host)
 {
@@ -302,6 +305,229 @@ static int sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 	return 0;
 }
 
+static int sdhci_uhs2_interface_detect(struct sdhci_host *host)
+{
+	u32 val;
+
+	if (read_poll_timeout(sdhci_readl, val, (val & SDHCI_UHS2_IF_DETECT),
+			      100, UHS2_INTERFACE_DETECT_TIMEOUT_100MS, true,
+			      host, SDHCI_PRESENT_STATE)) {
+		pr_warn("%s: not detect UHS2 interface in 100ms.\n", mmc_hostname(host->mmc));
+		sdhci_dumpregs(host);
+		return -EIO;
+	}
+
+	/* Enable UHS2 error interrupts */
+	sdhci_uhs2_clear_set_irqs(host, SDHCI_INT_ALL_MASK, SDHCI_UHS2_INT_ERROR_MASK);
+
+	if (read_poll_timeout(sdhci_readl, val, (val & SDHCI_UHS2_LANE_SYNC),
+			      100, UHS2_LANE_SYNC_TIMEOUT_150MS, true, host, SDHCI_PRESENT_STATE)) {
+		pr_warn("%s: UHS2 Lane sync fail in 150ms.\n", mmc_hostname(host->mmc));
+		sdhci_dumpregs(host);
+		return -EIO;
+	}
+
+	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;
+
+	caps_ptr = sdhci_readw(host, SDHCI_UHS2_CAPS_PTR);
+	if (caps_ptr < 0x100 || caps_ptr > 0x1FF) {
+		pr_err("%s: SDHCI_UHS2_CAPS_PTR(%d) is wrong.\n",
+		       mmc_hostname(mmc), caps_ptr);
+		return -ENODEV;
+	}
+	caps_gen = sdhci_readl(host, caps_ptr + SDHCI_UHS2_CAPS_OFFSET);
+	caps_phy = sdhci_readl(host, caps_ptr + SDHCI_UHS2_CAPS_PHY_OFFSET);
+	caps_tran[0] = sdhci_readl(host, caps_ptr + SDHCI_UHS2_CAPS_TRAN_OFFSET);
+	caps_tran[1] = sdhci_readl(host, caps_ptr + SDHCI_UHS2_CAPS_TRAN_1_OFFSET);
+
+	/* General Caps */
+	mmc->uhs2_caps.dap = caps_gen & SDHCI_UHS2_CAPS_DAP_MASK;
+	mmc->uhs2_caps.gap = FIELD_GET(SDHCI_UHS2_CAPS_GAP_MASK, caps_gen);
+	mmc->uhs2_caps.n_lanes = FIELD_GET(SDHCI_UHS2_CAPS_LANE_MASK, caps_gen);
+	mmc->uhs2_caps.addr64 =	(caps_gen & SDHCI_UHS2_CAPS_ADDR_64) ? 1 : 0;
+	mmc->uhs2_caps.card_type = FIELD_GET(SDHCI_UHS2_CAPS_DEV_TYPE_MASK, caps_gen);
+
+	/* PHY Caps */
+	mmc->uhs2_caps.phy_rev = caps_phy & SDHCI_UHS2_CAPS_PHY_REV_MASK;
+	mmc->uhs2_caps.speed_range = FIELD_GET(SDHCI_UHS2_CAPS_PHY_RANGE_MASK, caps_phy);
+	mmc->uhs2_caps.n_lss_sync = FIELD_GET(SDHCI_UHS2_CAPS_PHY_N_LSS_SYN_MASK, caps_phy);
+	mmc->uhs2_caps.n_lss_dir = FIELD_GET(SDHCI_UHS2_CAPS_PHY_N_LSS_DIR_MASK, caps_phy);
+	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_CAPS_TRAN_LINK_REV_MASK;
+	mmc->uhs2_caps.n_fcu = FIELD_GET(SDHCI_UHS2_CAPS_TRAN_N_FCU_MASK, caps_tran[0]);
+	if (mmc->uhs2_caps.n_fcu == 0)
+		mmc->uhs2_caps.n_fcu = 256;
+	mmc->uhs2_caps.host_type = FIELD_GET(SDHCI_UHS2_CAPS_TRAN_HOST_TYPE_MASK, caps_tran[0]);
+	mmc->uhs2_caps.maxblk_len = FIELD_GET(SDHCI_UHS2_CAPS_TRAN_BLK_LEN_MASK, caps_tran[0]);
+	mmc->uhs2_caps.n_data_gap = caps_tran[1] & SDHCI_UHS2_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);
+
+	DBG("Begin do uhs2 detect init.\n");
+
+	if (sdhci_uhs2_interface_detect(host)) {
+		pr_warn("%s: cannot detect UHS2 interface.\n", mmc_hostname(host->mmc));
+		return -EIO;
+	}
+
+	if (sdhci_uhs2_init(host)) {
+		pr_warn("%s: UHS2 init fail.\n", mmc_hostname(host->mmc));
+		return -EIO;
+	}
+
+	/* 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_INT_ERROR_MASK);
+	/*
+	 * N.B 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);
+
+	return 0;
+}
+
+static int sdhci_uhs2_disable_clk(struct mmc_host *mmc)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	u16 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+
+	clk &= ~SDHCI_CLOCK_CARD_EN;
+	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+	return 0;
+}
+
+static int sdhci_uhs2_enable_clk(struct mmc_host *mmc)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	u16 clk = sdhci_readw(host, SDHCI_CLOCK_CONTROL);
+	int timeout_us = 20000; /* 20ms */
+	u32 val;
+
+	clk |= SDHCI_CLOCK_CARD_EN;
+	sdhci_writew(host, clk, SDHCI_CLOCK_CONTROL);
+
+	if (read_poll_timeout(sdhci_readw, val, (val & SDHCI_CLOCK_INT_STABLE),
+			      10, timeout_us, true, host, SDHCI_CLOCK_CONTROL)) {
+		pr_err("%s: Internal clock never stabilised.\n", mmc_hostname(host->mmc));
+		sdhci_dumpregs(host);
+		return -EIO;
+	}
+	return 0;
+}
+
+static void sdhci_uhs2_set_config(struct sdhci_host *host)
+{
+	u32 value;
+	u16 sdhci_uhs2_set_ptr = sdhci_readw(host, SDHCI_UHS2_SETTINGS_PTR);
+	u16 sdhci_uhs2_gen_set_reg	= sdhci_uhs2_set_ptr;
+	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 */
+	value = FIELD_PREP(SDHCI_UHS2_GEN_SETTINGS_N_LANES_MASK, host->mmc->uhs2_caps.n_lanes_set);
+	sdhci_writel(host, value, sdhci_uhs2_gen_set_reg);
+
+	/* Set PHY Settings */
+	value = FIELD_PREP(SDHCI_UHS2_PHY_N_LSS_DIR_MASK, host->mmc->uhs2_caps.n_lss_dir_set) |
+		FIELD_PREP(SDHCI_UHS2_PHY_N_LSS_SYN_MASK, host->mmc->uhs2_caps.n_lss_sync_set);
+	if (host->mmc->ios.timing == MMC_TIMING_UHS2_SPEED_B ||
+	    host->mmc->ios.timing == MMC_TIMING_UHS2_SPEED_B_HD)
+		value |= SDHCI_UHS2_PHY_SET_SPEED_B;
+	sdhci_writel(host, value, sdhci_uhs2_phy_set_reg);
+
+	/* Set LINK-TRAN Settings */
+	value = FIELD_PREP(SDHCI_UHS2_TRAN_RETRY_CNT_MASK, host->mmc->uhs2_caps.max_retry_set) |
+		FIELD_PREP(SDHCI_UHS2_TRAN_N_FCU_MASK, host->mmc->uhs2_caps.n_fcu_set);
+	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)
+{
+	u32 val;
+
+	if (read_poll_timeout(sdhci_readl, val, (val & SDHCI_UHS2_IN_DORMANT_STATE),
+			      100, UHS2_CHECK_DORMANT_TIMEOUT_100MS, true, host,
+			      SDHCI_PRESENT_STATE)) {
+		pr_warn("%s: UHS2 IN_DORMANT fail in 100ms.\n", mmc_hostname(host->mmc));
+		sdhci_dumpregs(host);
+		return -EIO;
+	}
+	return 0;
+}
+
+static int sdhci_uhs2_control(struct mmc_host *mmc, enum sd_uhs2_operation op)
+{
+	struct sdhci_host *host = mmc_priv(mmc);
+	struct mmc_ios *ios = &mmc->ios;
+	int err = 0;
+
+	DBG("Begin uhs2 control, act %d.\n", op);
+
+	switch (op) {
+	case UHS2_PHY_INIT:
+		err = sdhci_uhs2_do_detect_init(mmc);
+		break;
+	case UHS2_SET_CONFIG:
+		sdhci_uhs2_set_config(host);
+		break;
+	case UHS2_ENABLE_INT:
+		sdhci_uhs2_clear_set_irqs(host, 0, SDHCI_INT_CARD_INT);
+		break;
+	case UHS2_DISABLE_INT:
+		sdhci_uhs2_clear_set_irqs(host, SDHCI_INT_CARD_INT, 0);
+		break;
+	case UHS2_CHECK_DORMANT:
+		err = sdhci_uhs2_check_dormant(host);
+		break;
+	case UHS2_DISABLE_CLK:
+		err = sdhci_uhs2_disable_clk(mmc);
+		break;
+	case UHS2_ENABLE_CLK:
+		err = sdhci_uhs2_enable_clk(mmc);
+		break;
+	case UHS2_SET_IOS:
+		err = sdhci_uhs2_set_ios(mmc, ios);
+		break;
+	default:
+		pr_err("%s: input sd uhs2 operation %d is wrong!\n",
+		       mmc_hostname(host->mmc), op);
+		err = -EIO;
+		break;
+	}
+
+	return err;
+}
+
 /*****************************************************************************\
  *                                                                           *
  * Driver init/exit                                                          *
@@ -310,6 +536,8 @@ static int sdhci_uhs2_set_ios(struct mmc_host *mmc, struct mmc_ios *ios)
 
 static int sdhci_uhs2_host_ops_init(struct sdhci_host *host)
 {
+	host->mmc_host_ops.uhs2_control = sdhci_uhs2_control;
+
 	return 0;
 }
 
-- 
2.25.1