phy: Add driver for Cadence MHDP DisplayPort SD0801 PHY

Add driver for the Cadence SD0801 "Torrent" PHY used with the Cadence MHDP
DisplayPort Tx controller.

Integration with the MHDP driver will be the subject of another commit.

Signed-off-by: Scott Telford <stelford@cadence.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>

5 files changed, 554 insertions, 0 deletions

diff --git a/drivers/phy/Kconfig b/drivers/phy/Kconfig
index 5c8d452e35e2..cc47f8508850 100644
--- a/drivers/phy/Kconfig
+++ b/drivers/phy/Kconfig
@@ -43,6 +43,7 @@ config PHY_XGENE
 source "drivers/phy/allwinner/Kconfig"
 source "drivers/phy/amlogic/Kconfig"
 source "drivers/phy/broadcom/Kconfig"
+source "drivers/phy/cadence/Kconfig"
 source "drivers/phy/hisilicon/Kconfig"
 source "drivers/phy/lantiq/Kconfig"
 source "drivers/phy/marvell/Kconfig"
diff --git a/drivers/phy/Makefile b/drivers/phy/Makefile
index 84e3bd9c5665..ba48acdd9ed1 100644
--- a/drivers/phy/Makefile
+++ b/drivers/phy/Makefile
@@ -15,6 +15,7 @@ obj-$(CONFIG_ARCH_RENESAS)		+= renesas/
 obj-$(CONFIG_ARCH_ROCKCHIP)		+= rockchip/
 obj-$(CONFIG_ARCH_TEGRA)		+= tegra/
 obj-y					+= broadcom/	\
+					   cadence/	\
 					   hisilicon/	\
 					   marvell/	\
 					   motorola/	\
diff --git a/drivers/phy/cadence/Kconfig b/drivers/phy/cadence/Kconfig
new file mode 100644
index 000000000000..57fff7de4031
--- /dev/null
+++ b/drivers/phy/cadence/Kconfig
@@ -0,0 +1,10 @@
+#
+# Phy driver for Cadence MHDP DisplayPort controller
+#
+config PHY_CADENCE_DP
+	tristate "Cadence MHDP DisplayPort PHY driver"
+	depends on OF
+	depends on HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Support for Cadence MHDP DisplayPort PHY.
diff --git a/drivers/phy/cadence/Makefile b/drivers/phy/cadence/Makefile
new file mode 100644
index 000000000000..e5b0a11cf28a
--- /dev/null
+++ b/drivers/phy/cadence/Makefile
@@ -0,0 +1 @@
+obj-$(CONFIG_PHY_CADENCE_DP)	+= phy-cadence-dp.o
diff --git a/drivers/phy/cadence/phy-cadence-dp.c b/drivers/phy/cadence/phy-cadence-dp.c
new file mode 100644
index 000000000000..bc10cb264b7a
--- /dev/null
+++ b/drivers/phy/cadence/phy-cadence-dp.c
@@ -0,0 +1,541 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Cadence MHDP DisplayPort SD0801 PHY driver.
+ *
+ * Copyright 2018 Cadence Design Systems, Inc.
+ *
+ */
+
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/iopoll.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+
+#define DEFAULT_NUM_LANES	2
+#define MAX_NUM_LANES		4
+#define DEFAULT_MAX_BIT_RATE	8100 /* in Mbps */
+
+#define POLL_TIMEOUT_US		2000
+#define LANE_MASK		0x7
+
+/*
+ * register offsets from DPTX PHY register block base (i.e MHDP
+ * register base + 0x30a00)
+ */
+#define PHY_AUX_CONFIG			0x00
+#define PHY_AUX_CTRL			0x04
+#define PHY_RESET			0x20
+#define PHY_PMA_XCVR_PLLCLK_EN		0x24
+#define PHY_PMA_XCVR_PLLCLK_EN_ACK	0x28
+#define PHY_PMA_XCVR_POWER_STATE_REQ	0x2c
+#define PHY_POWER_STATE_LN_0	0x0000
+#define PHY_POWER_STATE_LN_1	0x0008
+#define PHY_POWER_STATE_LN_2	0x0010
+#define PHY_POWER_STATE_LN_3	0x0018
+#define PHY_PMA_XCVR_POWER_STATE_ACK	0x30
+#define PHY_PMA_CMN_READY		0x34
+#define PHY_PMA_XCVR_TX_VMARGIN		0x38
+#define PHY_PMA_XCVR_TX_DEEMPH		0x3c
+
+/*
+ * register offsets from SD0801 PHY register block base (i.e MHDP
+ * register base + 0x500000)
+ */
+#define CMN_SSM_BANDGAP_TMR		0x00084
+#define CMN_SSM_BIAS_TMR		0x00088
+#define CMN_PLLSM0_PLLPRE_TMR		0x000a8
+#define CMN_PLLSM0_PLLLOCK_TMR		0x000b0
+#define CMN_PLLSM1_PLLPRE_TMR		0x000c8
+#define CMN_PLLSM1_PLLLOCK_TMR		0x000d0
+#define CMN_BGCAL_INIT_TMR		0x00190
+#define CMN_BGCAL_ITER_TMR		0x00194
+#define CMN_IBCAL_INIT_TMR		0x001d0
+#define CMN_PLL0_VCOCAL_INIT_TMR	0x00210
+#define CMN_PLL0_VCOCAL_ITER_TMR	0x00214
+#define CMN_PLL0_VCOCAL_REFTIM_START	0x00218
+#define CMN_PLL0_VCOCAL_PLLCNT_START	0x00220
+#define CMN_PLL0_INTDIV_M0		0x00240
+#define CMN_PLL0_FRACDIVL_M0		0x00244
+#define CMN_PLL0_FRACDIVH_M0		0x00248
+#define CMN_PLL0_HIGH_THR_M0		0x0024c
+#define CMN_PLL0_DSM_DIAG_M0		0x00250
+#define CMN_PLL0_LOCK_PLLCNT_START	0x00278
+#define CMN_PLL1_VCOCAL_INIT_TMR	0x00310
+#define CMN_PLL1_VCOCAL_ITER_TMR	0x00314
+#define CMN_PLL1_DSM_DIAG_M0		0x00350
+#define CMN_TXPUCAL_INIT_TMR		0x00410
+#define CMN_TXPUCAL_ITER_TMR		0x00414
+#define CMN_TXPDCAL_INIT_TMR		0x00430
+#define CMN_TXPDCAL_ITER_TMR		0x00434
+#define CMN_RXCAL_INIT_TMR		0x00450
+#define CMN_RXCAL_ITER_TMR		0x00454
+#define CMN_SD_CAL_INIT_TMR		0x00490
+#define CMN_SD_CAL_ITER_TMR		0x00494
+#define CMN_SD_CAL_REFTIM_START		0x00498
+#define CMN_SD_CAL_PLLCNT_START		0x004a0
+#define CMN_PDIAG_PLL0_CTRL_M0		0x00680
+#define CMN_PDIAG_PLL0_CLK_SEL_M0	0x00684
+#define CMN_PDIAG_PLL0_CP_PADJ_M0	0x00690
+#define CMN_PDIAG_PLL0_CP_IADJ_M0	0x00694
+#define CMN_PDIAG_PLL0_FILT_PADJ_M0	0x00698
+#define CMN_PDIAG_PLL0_CP_PADJ_M1	0x006d0
+#define CMN_PDIAG_PLL0_CP_IADJ_M1	0x006d4
+#define CMN_PDIAG_PLL1_CLK_SEL_M0	0x00704
+#define XCVR_DIAG_PLLDRC_CTRL		0x10394
+#define XCVR_DIAG_HSCLK_SEL		0x10398
+#define XCVR_DIAG_HSCLK_DIV		0x1039c
+#define TX_PSC_A0			0x10400
+#define TX_PSC_A1			0x10404
+#define TX_PSC_A2			0x10408
+#define TX_PSC_A3			0x1040c
+#define RX_PSC_A0			0x20000
+#define RX_PSC_A1			0x20004
+#define RX_PSC_A2			0x20008
+#define RX_PSC_A3			0x2000c
+#define PHY_PLL_CFG			0x30038
+
+struct cdns_dp_phy {
+	void __iomem *base;	/* DPTX registers base */
+	void __iomem *sd_base; /* SD0801 registers base */
+	u32 num_lanes; /* Number of lanes to use */
+	u32 max_bit_rate; /* Maximum link bit rate to use (in Mbps) */
+	struct device *dev;
+};
+
+static int cdns_dp_phy_init(struct phy *phy);
+static void cdns_dp_phy_run(struct cdns_dp_phy *cdns_phy);
+static void cdns_dp_phy_wait_pma_cmn_ready(struct cdns_dp_phy *cdns_phy);
+static void cdns_dp_phy_pma_cfg(struct cdns_dp_phy *cdns_phy);
+static void cdns_dp_phy_pma_cmn_cfg_25mhz(struct cdns_dp_phy *cdns_phy);
+static void cdns_dp_phy_pma_lane_cfg(struct cdns_dp_phy *cdns_phy,
+					 unsigned int lane);
+static void cdns_dp_phy_pma_cmn_vco_cfg_25mhz(struct cdns_dp_phy *cdns_phy);
+static void cdns_dp_phy_pma_cmn_rate(struct cdns_dp_phy *cdns_phy);
+static void cdns_dp_phy_write_field(struct cdns_dp_phy *cdns_phy,
+					unsigned int offset,
+					unsigned char start_bit,
+					unsigned char num_bits,
+					unsigned int val);
+
+static const struct phy_ops cdns_dp_phy_ops = {
+	.init		= cdns_dp_phy_init,
+	.owner		= THIS_MODULE,
+};
+
+static int cdns_dp_phy_init(struct phy *phy)
+{
+	unsigned char lane_bits;
+
+	struct cdns_dp_phy *cdns_phy = phy_get_drvdata(phy);
+
+	writel(0x0003, cdns_phy->base + PHY_AUX_CTRL); /* enable AUX */
+
+	/* PHY PMA registers configuration function */
+	cdns_dp_phy_pma_cfg(cdns_phy);
+
+	/*
+	 * Set lines power state to A0
+	 * Set lines pll clk enable to 0
+	 */
+
+	cdns_dp_phy_write_field(cdns_phy, PHY_PMA_XCVR_POWER_STATE_REQ,
+				PHY_POWER_STATE_LN_0, 6, 0x0000);
+
+	if (cdns_phy->num_lanes >= 2) {
+		cdns_dp_phy_write_field(cdns_phy,
+					PHY_PMA_XCVR_POWER_STATE_REQ,
+					PHY_POWER_STATE_LN_1, 6, 0x0000);
+
+		if (cdns_phy->num_lanes == 4) {
+			cdns_dp_phy_write_field(cdns_phy,
+						PHY_PMA_XCVR_POWER_STATE_REQ,
+						PHY_POWER_STATE_LN_2, 6, 0);
+			cdns_dp_phy_write_field(cdns_phy,
+						PHY_PMA_XCVR_POWER_STATE_REQ,
+						PHY_POWER_STATE_LN_3, 6, 0);
+		}
+	}
+
+	cdns_dp_phy_write_field(cdns_phy, PHY_PMA_XCVR_PLLCLK_EN,
+				0, 1, 0x0000);
+
+	if (cdns_phy->num_lanes >= 2) {
+		cdns_dp_phy_write_field(cdns_phy, PHY_PMA_XCVR_PLLCLK_EN,
+					1, 1, 0x0000);
+		if (cdns_phy->num_lanes == 4) {
+			cdns_dp_phy_write_field(cdns_phy,
+						PHY_PMA_XCVR_PLLCLK_EN,
+						2, 1, 0x0000);
+			cdns_dp_phy_write_field(cdns_phy,
+						PHY_PMA_XCVR_PLLCLK_EN,
+						3, 1, 0x0000);
+		}
+	}
+
+	/*
+	 * release phy_l0*_reset_n and pma_tx_elec_idle_ln_* based on
+	 * used lanes
+	 */
+	lane_bits = (1 << cdns_phy->num_lanes) - 1;
+	writel(((0xF & ~lane_bits) << 4) | (0xF & lane_bits),
+		   cdns_phy->base + PHY_RESET);
+
+	/* release pma_xcvr_pllclk_en_ln_*, only for the master lane */
+	writel(0x0001, cdns_phy->base + PHY_PMA_XCVR_PLLCLK_EN);
+
+	/* PHY PMA registers configuration functions */
+	cdns_dp_phy_pma_cmn_vco_cfg_25mhz(cdns_phy);
+	cdns_dp_phy_pma_cmn_rate(cdns_phy);
+
+	/* take out of reset */
+	cdns_dp_phy_write_field(cdns_phy, PHY_RESET, 8, 1, 1);
+	cdns_dp_phy_wait_pma_cmn_ready(cdns_phy);
+	cdns_dp_phy_run(cdns_phy);
+
+	return 0;
+}
+
+static void cdns_dp_phy_wait_pma_cmn_ready(struct cdns_dp_phy *cdns_phy)
+{
+	unsigned int reg;
+	int ret;
+
+	ret = readl_poll_timeout(cdns_phy->base + PHY_PMA_CMN_READY, reg,
+				 reg & 1, 0, 500);
+	if (ret == -ETIMEDOUT)
+		dev_err(cdns_phy->dev,
+			"timeout waiting for PMA common ready\n");
+}
+
+static void cdns_dp_phy_pma_cfg(struct cdns_dp_phy *cdns_phy)
+{
+	unsigned int i;
+
+	/* PMA common configuration */
+	cdns_dp_phy_pma_cmn_cfg_25mhz(cdns_phy);
+
+	/* PMA lane configuration to deal with multi-link operation */
+	for (i = 0; i < cdns_phy->num_lanes; i++)
+		cdns_dp_phy_pma_lane_cfg(cdns_phy, i);
+}
+
+static void cdns_dp_phy_pma_cmn_cfg_25mhz(struct cdns_dp_phy *cdns_phy)
+{
+	/* refclock registers - assumes 25 MHz refclock */
+	writel(0x0019, cdns_phy->sd_base + CMN_SSM_BIAS_TMR);
+	writel(0x0032, cdns_phy->sd_base + CMN_PLLSM0_PLLPRE_TMR);
+	writel(0x00D1, cdns_phy->sd_base + CMN_PLLSM0_PLLLOCK_TMR);
+	writel(0x0032, cdns_phy->sd_base + CMN_PLLSM1_PLLPRE_TMR);
+	writel(0x00D1, cdns_phy->sd_base + CMN_PLLSM1_PLLLOCK_TMR);
+	writel(0x007D, cdns_phy->sd_base + CMN_BGCAL_INIT_TMR);
+	writel(0x007D, cdns_phy->sd_base + CMN_BGCAL_ITER_TMR);
+	writel(0x0019, cdns_phy->sd_base + CMN_IBCAL_INIT_TMR);
+	writel(0x001E, cdns_phy->sd_base + CMN_TXPUCAL_INIT_TMR);
+	writel(0x0006, cdns_phy->sd_base + CMN_TXPUCAL_ITER_TMR);
+	writel(0x001E, cdns_phy->sd_base + CMN_TXPDCAL_INIT_TMR);
+	writel(0x0006, cdns_phy->sd_base + CMN_TXPDCAL_ITER_TMR);
+	writel(0x02EE, cdns_phy->sd_base + CMN_RXCAL_INIT_TMR);
+	writel(0x0006, cdns_phy->sd_base + CMN_RXCAL_ITER_TMR);
+	writel(0x0002, cdns_phy->sd_base + CMN_SD_CAL_INIT_TMR);
+	writel(0x0002, cdns_phy->sd_base + CMN_SD_CAL_ITER_TMR);
+	writel(0x000E, cdns_phy->sd_base + CMN_SD_CAL_REFTIM_START);
+	writel(0x012B, cdns_phy->sd_base + CMN_SD_CAL_PLLCNT_START);
+	/* PLL registers */
+	writel(0x0409, cdns_phy->sd_base + CMN_PDIAG_PLL0_CP_PADJ_M0);
+	writel(0x1001, cdns_phy->sd_base + CMN_PDIAG_PLL0_CP_IADJ_M0);
+	writel(0x0F08, cdns_phy->sd_base + CMN_PDIAG_PLL0_FILT_PADJ_M0);
+	writel(0x0004, cdns_phy->sd_base + CMN_PLL0_DSM_DIAG_M0);
+	writel(0x00FA, cdns_phy->sd_base + CMN_PLL0_VCOCAL_INIT_TMR);
+	writel(0x0004, cdns_phy->sd_base + CMN_PLL0_VCOCAL_ITER_TMR);
+	writel(0x00FA, cdns_phy->sd_base + CMN_PLL1_VCOCAL_INIT_TMR);
+	writel(0x0004, cdns_phy->sd_base + CMN_PLL1_VCOCAL_ITER_TMR);
+	writel(0x0318, cdns_phy->sd_base + CMN_PLL0_VCOCAL_REFTIM_START);
+}
+
+static void cdns_dp_phy_pma_cmn_vco_cfg_25mhz(struct cdns_dp_phy *cdns_phy)
+{
+	/* Assumes 25 MHz refclock */
+	switch (cdns_phy->max_bit_rate) {
+		/* Setting VCO for 10.8GHz */
+	case 2700:
+	case 5400:
+		writel(0x01B0, cdns_phy->sd_base + CMN_PLL0_INTDIV_M0);
+		writel(0x0000, cdns_phy->sd_base + CMN_PLL0_FRACDIVL_M0);
+		writel(0x0002, cdns_phy->sd_base + CMN_PLL0_FRACDIVH_M0);
+		writel(0x0120, cdns_phy->sd_base + CMN_PLL0_HIGH_THR_M0);
+		break;
+		/* Setting VCO for 9.72GHz */
+	case 2430:
+	case 3240:
+		writel(0x0184, cdns_phy->sd_base + CMN_PLL0_INTDIV_M0);
+		writel(0xCCCD, cdns_phy->sd_base + CMN_PLL0_FRACDIVL_M0);
+		writel(0x0002, cdns_phy->sd_base + CMN_PLL0_FRACDIVH_M0);
+		writel(0x0104, cdns_phy->sd_base + CMN_PLL0_HIGH_THR_M0);
+		break;
+		/* Setting VCO for 8.64GHz */
+	case 2160:
+	case 4320:
+		writel(0x0159, cdns_phy->sd_base + CMN_PLL0_INTDIV_M0);
+		writel(0x999A, cdns_phy->sd_base + CMN_PLL0_FRACDIVL_M0);
+		writel(0x0002, cdns_phy->sd_base + CMN_PLL0_FRACDIVH_M0);
+		writel(0x00E7, cdns_phy->sd_base + CMN_PLL0_HIGH_THR_M0);
+		break;
+		/* Setting VCO for 8.1GHz */
+	case 8100:
+		writel(0x0144, cdns_phy->sd_base + CMN_PLL0_INTDIV_M0);
+		writel(0x0000, cdns_phy->sd_base + CMN_PLL0_FRACDIVL_M0);
+		writel(0x0002, cdns_phy->sd_base + CMN_PLL0_FRACDIVH_M0);
+		writel(0x00D8, cdns_phy->sd_base + CMN_PLL0_HIGH_THR_M0);
+		break;
+	}
+
+	writel(0x0002, cdns_phy->sd_base + CMN_PDIAG_PLL0_CTRL_M0);
+	writel(0x0318, cdns_phy->sd_base + CMN_PLL0_VCOCAL_PLLCNT_START);
+}
+
+static void cdns_dp_phy_pma_cmn_rate(struct cdns_dp_phy *cdns_phy)
+{
+	unsigned int clk_sel_val = 0;
+	unsigned int hsclk_div_val = 0;
+	unsigned int i;
+
+	/* 16'h0000 for single DP link configuration */
+	writel(0x0000, cdns_phy->sd_base + PHY_PLL_CFG);
+
+	switch (cdns_phy->max_bit_rate) {
+	case 1620:
+		clk_sel_val = 0x0f01;
+		hsclk_div_val = 2;
+		break;
+	case 2160:
+	case 2430:
+	case 2700:
+		clk_sel_val = 0x0701;
+		 hsclk_div_val = 1;
+		break;
+	case 3240:
+		clk_sel_val = 0x0b00;
+		hsclk_div_val = 2;
+		break;
+	case 4320:
+	case 5400:
+		clk_sel_val = 0x0301;
+		hsclk_div_val = 0;
+		break;
+	case 8100:
+		clk_sel_val = 0x0200;
+		hsclk_div_val = 0;
+		break;
+	}
+
+	writel(clk_sel_val, cdns_phy->sd_base + CMN_PDIAG_PLL0_CLK_SEL_M0);
+
+	/* PMA lane configuration to deal with multi-link operation */
+	for (i = 0; i < cdns_phy->num_lanes; i++) {
+		writel(hsclk_div_val,
+		       cdns_phy->sd_base + (XCVR_DIAG_HSCLK_DIV | (i<<11)));
+	}
+}
+
+static void cdns_dp_phy_pma_lane_cfg(struct cdns_dp_phy *cdns_phy,
+				     unsigned int lane)
+{
+	unsigned int lane_bits = (lane & LANE_MASK) << 11;
+
+	/* Writing Tx/Rx Power State Controllers registers */
+	writel(0x00FB, cdns_phy->sd_base + (TX_PSC_A0 | lane_bits));
+	writel(0x04AA, cdns_phy->sd_base + (TX_PSC_A2 | lane_bits));
+	writel(0x04AA, cdns_phy->sd_base + (TX_PSC_A3 | lane_bits));
+	writel(0x0000, cdns_phy->sd_base + (RX_PSC_A0 | lane_bits));
+	writel(0x0000, cdns_phy->sd_base + (RX_PSC_A2 | lane_bits));
+	writel(0x0000, cdns_phy->sd_base + (RX_PSC_A3 | lane_bits));
+
+	writel(0x0001, cdns_phy->sd_base + (XCVR_DIAG_PLLDRC_CTRL | lane_bits));
+	writel(0x0000, cdns_phy->sd_base + (XCVR_DIAG_HSCLK_SEL | lane_bits));
+}
+
+static void cdns_dp_phy_run(struct cdns_dp_phy *cdns_phy)
+{
+	unsigned int read_val;
+	u32 write_val1 = 0;
+	u32 write_val2 = 0;
+	u32 mask = 0;
+	int ret;
+
+	/*
+	 * waiting for ACK of pma_xcvr_pllclk_en_ln_*, only for the
+	 * master lane
+	 */
+	ret = readl_poll_timeout(cdns_phy->base + PHY_PMA_XCVR_PLLCLK_EN_ACK,
+				 read_val, read_val & 1, 0, POLL_TIMEOUT_US);
+	if (ret == -ETIMEDOUT)
+		dev_err(cdns_phy->dev,
+			"timeout waiting for link PLL clock enable ack\n");
+
+	ndelay(100);
+
+	switch (cdns_phy->num_lanes) {
+
+	case 1:	/* lane 0 */
+		write_val1 = 0x00000004;
+		write_val2 = 0x00000001;
+		mask = 0x0000003f;
+		break;
+	case 2: /* lane 0-1 */
+		write_val1 = 0x00000404;
+		write_val2 = 0x00000101;
+		mask = 0x00003f3f;
+		break;
+	case 4: /* lane 0-3 */
+		write_val1 = 0x04040404;
+		write_val2 = 0x01010101;
+		mask = 0x3f3f3f3f;
+		break;
+	}
+
+	writel(write_val1, cdns_phy->base + PHY_PMA_XCVR_POWER_STATE_REQ);
+
+	ret = readl_poll_timeout(cdns_phy->base + PHY_PMA_XCVR_POWER_STATE_ACK,
+				 read_val, (read_val & mask) == write_val1, 0,
+				 POLL_TIMEOUT_US);
+	if (ret == -ETIMEDOUT)
+		dev_err(cdns_phy->dev,
+			"timeout waiting for link power state ack\n");
+
+	writel(0, cdns_phy->base + PHY_PMA_XCVR_POWER_STATE_REQ);
+	ndelay(100);
+
+	writel(write_val2, cdns_phy->base + PHY_PMA_XCVR_POWER_STATE_REQ);
+
+	ret = readl_poll_timeout(cdns_phy->base + PHY_PMA_XCVR_POWER_STATE_ACK,
+				 read_val, (read_val & mask) == write_val2, 0,
+				 POLL_TIMEOUT_US);
+	if (ret == -ETIMEDOUT)
+		dev_err(cdns_phy->dev,
+			"timeout waiting for link power state ack\n");
+
+	writel(0, cdns_phy->base + PHY_PMA_XCVR_POWER_STATE_REQ);
+	ndelay(100);
+}
+
+static void cdns_dp_phy_write_field(struct cdns_dp_phy *cdns_phy,
+				    unsigned int offset,
+				    unsigned char start_bit,
+				    unsigned char num_bits,
+				    unsigned int val)
+{
+	unsigned int read_val;
+
+	read_val = readl(cdns_phy->base + offset);
+	writel(((val << start_bit) | (read_val & ~(((1 << num_bits) - 1) <<
+		start_bit))), cdns_phy->base + offset);
+}
+
+static int cdns_dp_phy_probe(struct platform_device *pdev)
+{
+	struct resource *regs;
+	struct cdns_dp_phy *cdns_phy;
+	struct device *dev = &pdev->dev;
+	struct phy_provider *phy_provider;
+	struct phy *phy;
+	int err;
+
+	cdns_phy = devm_kzalloc(dev, sizeof(*cdns_phy), GFP_KERNEL);
+	if (!cdns_phy)
+		return -ENOMEM;
+
+	cdns_phy->dev = &pdev->dev;
+
+	phy = devm_phy_create(dev, NULL, &cdns_dp_phy_ops);
+	if (IS_ERR(phy)) {
+		dev_err(dev, "failed to create DisplayPort PHY\n");
+		return PTR_ERR(phy);
+	}
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	cdns_phy->base = devm_ioremap_resource(&pdev->dev, regs);
+	if (IS_ERR(cdns_phy->base))
+		return PTR_ERR(cdns_phy->base);
+
+	regs = platform_get_resource(pdev, IORESOURCE_MEM, 1);
+	cdns_phy->sd_base = devm_ioremap_resource(&pdev->dev, regs);
+	if (IS_ERR(cdns_phy->sd_base))
+		return PTR_ERR(cdns_phy->sd_base);
+
+	err = device_property_read_u32(dev, "num_lanes",
+				       &(cdns_phy->num_lanes));
+	if (err)
+		cdns_phy->num_lanes = DEFAULT_NUM_LANES;
+
+	switch (cdns_phy->num_lanes) {
+	case 1:
+	case 2:
+	case 4:
+		/* valid number of lanes */
+		break;
+	default:
+		dev_err(dev, "unsupported number of lanes: %d\n",
+			cdns_phy->num_lanes);
+		return -EINVAL;
+	}
+
+	err = device_property_read_u32(dev, "max_bit_rate",
+		   &(cdns_phy->max_bit_rate));
+	if (err)
+		cdns_phy->max_bit_rate = DEFAULT_MAX_BIT_RATE;
+
+	switch (cdns_phy->max_bit_rate) {
+	case 2160:
+	case 2430:
+	case 2700:
+	case 3240:
+	case 4320:
+	case 5400:
+	case 8100:
+		/* valid bit rate */
+		break;
+	default:
+		dev_err(dev, "unsupported max bit rate: %dMbps\n",
+			cdns_phy->max_bit_rate);
+		return -EINVAL;
+	}
+
+	phy_set_drvdata(phy, cdns_phy);
+
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+
+	dev_info(dev, "%d lanes, max bit rate %d.%03d Gbps\n",
+		 cdns_phy->num_lanes,
+		 cdns_phy->max_bit_rate / 1000,
+		 cdns_phy->max_bit_rate % 1000);
+
+	return PTR_ERR_OR_ZERO(phy_provider);
+}
+
+static const struct of_device_id cdns_dp_phy_of_match[] = {
+	{
+		.compatible = "cdns,dp-phy"
+	},
+	{}
+};
+MODULE_DEVICE_TABLE(of, cdns_dp_phy_of_match);
+
+static struct platform_driver cdns_dp_phy_driver = {
+	.probe	= cdns_dp_phy_probe,
+	.driver = {
+		.name	= "cdns-dp-phy",
+		.of_match_table	= cdns_dp_phy_of_match,
+	}
+};
+module_platform_driver(cdns_dp_phy_driver);
+
+MODULE_AUTHOR("Cadence Design Systems, Inc.");
+MODULE_DESCRIPTION("Cadence MHDP PHY driver");
+MODULE_LICENSE("GPL v2");