drm/msm/dsi: Add PHY/PLL for 8x96

Extend the DSI PHY/PLL drivers to support the DSI 14nm PHY/PLL
found on 8x96.

These are picked up from the downstream driver. The PHY part is similar
to the other DSI PHYs. The PLL driver requires some trickery so that
one DSI PLL can drive both the DSIs (i.e, dual DSI mode).

In the case of dual DSI mode. One DSI instance becomes the clock master,
and other the clock slave. The master PLL's output (Byte and Pixel clock)
is fed to both the DSI hosts/PHYs.

When the DSIs are configured in dual DSI mode, the PHY driver communicates
to the PLL driver using msm_dsi_pll_set_usecase() which instance is the
master and which one is the slave. When setting rate, the master PLL also
configures some of the slave PLL/PHY registers which need to be identical
to the master's for correct dual DSI behaviour.

There are 2 PLL post dividers that should have ideally been modelled as
generic clk_divider clocks, but require some customization for dual DSI.
In particular, when the master PLL's post-diviers are set, the slave PLL's
post-dividers need to be set too. The clk_ops for these use clk_divider's
helper ops and flags internally to prevent redundant code.

Cc: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>

drivers/gpu/drm/msm/Kconfig

@@ -72,3 +72,10 @@ config DRM_MSM_DSI_28NM_8960_PHY
 	help
 	  Choose this option if the 28nm DSI PHY 8960 variant is used on the
 	  platform.
+
+config DRM_MSM_DSI_14NM_PHY
+	bool "Enable DSI 14nm PHY driver in MSM DRM (used by MSM8996/APQ8096)"
+	depends on DRM_MSM_DSI
+	default y
+	help
+	  Choose this option if DSI PHY on 8996 is used on the platform.

drivers/gpu/drm/msm/Makefile

@@ -76,11 +76,13 @@ msm-$(CONFIG_DRM_MSM_DSI) += dsi/dsi.o \
 msm-$(CONFIG_DRM_MSM_DSI_28NM_PHY) += dsi/phy/dsi_phy_28nm.o
 msm-$(CONFIG_DRM_MSM_DSI_20NM_PHY) += dsi/phy/dsi_phy_20nm.o
 msm-$(CONFIG_DRM_MSM_DSI_28NM_8960_PHY) += dsi/phy/dsi_phy_28nm_8960.o
+msm-$(CONFIG_DRM_MSM_DSI_14NM_PHY) += dsi/phy/dsi_phy_14nm.o
 
 ifeq ($(CONFIG_DRM_MSM_DSI_PLL),y)
 msm-y += dsi/pll/dsi_pll.o
 msm-$(CONFIG_DRM_MSM_DSI_28NM_PHY) += dsi/pll/dsi_pll_28nm.o
 msm-$(CONFIG_DRM_MSM_DSI_28NM_8960_PHY) += dsi/pll/dsi_pll_28nm_8960.o
+msm-$(CONFIG_DRM_MSM_DSI_14NM_PHY) += dsi/pll/dsi_pll_14nm.o
 endif
 
 obj-$(CONFIG_DRM_MSM)	+= msm.o

drivers/gpu/drm/msm/dsi/dsi.h

@@ -35,6 +35,7 @@ enum msm_dsi_phy_type {
 	MSM_DSI_PHY_28NM_LP,
 	MSM_DSI_PHY_20NM,
 	MSM_DSI_PHY_28NM_8960,
+	MSM_DSI_PHY_14NM,
 	MSM_DSI_PHY_MAX
 };
 
@@ -117,6 +118,8 @@ int msm_dsi_pll_get_clk_provider(struct msm_dsi_pll *pll,
 	struct clk **byte_clk_provider, struct clk **pixel_clk_provider);
 void msm_dsi_pll_save_state(struct msm_dsi_pll *pll);
 int msm_dsi_pll_restore_state(struct msm_dsi_pll *pll);
+int msm_dsi_pll_set_usecase(struct msm_dsi_pll *pll,
+			    enum msm_dsi_phy_usecase uc);
 #else
 static inline struct msm_dsi_pll *msm_dsi_pll_init(struct platform_device *pdev,
 			 enum msm_dsi_phy_type type, int id) {
@@ -137,6 +140,11 @@ static inline int msm_dsi_pll_restore_state(struct msm_dsi_pll *pll)
 {
 	return 0;
 }
+static inline int msm_dsi_pll_set_usecase(struct msm_dsi_pll *pll,
+					  enum msm_dsi_phy_usecase uc)
+{
+	return -ENODEV;
+}
 #endif
 
 /* dsi host */

drivers/gpu/drm/msm/dsi/phy/dsi_phy.c

@@ -390,6 +390,10 @@ static const struct of_device_id dsi_phy_dt_match[] = {
 #ifdef CONFIG_DRM_MSM_DSI_28NM_8960_PHY
 	{ .compatible = "qcom,dsi-phy-28nm-8960",
 	  .data = &dsi_phy_28nm_8960_cfgs },
+#endif
+#ifdef CONFIG_DRM_MSM_DSI_14NM_PHY
+	{ .compatible = "qcom,dsi-phy-14nm",
+	  .data = &dsi_phy_14nm_cfgs },
 #endif
 	{}
 };

drivers/gpu/drm/msm/dsi/phy/dsi_phy.h

@@ -47,6 +47,7 @@ extern const struct msm_dsi_phy_cfg dsi_phy_28nm_hpm_cfgs;
 extern const struct msm_dsi_phy_cfg dsi_phy_28nm_lp_cfgs;
 extern const struct msm_dsi_phy_cfg dsi_phy_20nm_cfgs;
 extern const struct msm_dsi_phy_cfg dsi_phy_28nm_8960_cfgs;
+extern const struct msm_dsi_phy_cfg dsi_phy_14nm_cfgs;
 
 struct msm_dsi_dphy_timing {
 	u32 clk_pre;
@@ -77,6 +78,7 @@ struct msm_dsi_phy {
 	struct platform_device *pdev;
 	void __iomem *base;
 	void __iomem *reg_base;
+	void __iomem *lane_base;
 	int id;
 
 	struct clk *ahb_clk;

drivers/gpu/drm/msm/dsi/phy/dsi_phy_14nm.c

@@ -0,0 +1,169 @@
+/*
+ * Copyright (c) 2016, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include "dsi_phy.h"
+#include "dsi.xml.h"
+
+#define PHY_14NM_CKLN_IDX	4
+
+static void dsi_14nm_dphy_set_timing(struct msm_dsi_phy *phy,
+				     struct msm_dsi_dphy_timing *timing,
+				     int lane_idx)
+{
+	void __iomem *base = phy->lane_base;
+	bool clk_ln = (lane_idx == PHY_14NM_CKLN_IDX);
+	u32 zero = clk_ln ? timing->clk_zero : timing->hs_zero;
+	u32 prepare = clk_ln ? timing->clk_prepare : timing->hs_prepare;
+	u32 trail = clk_ln ? timing->clk_trail : timing->hs_trail;
+	u32 rqst = clk_ln ? timing->hs_rqst_ckln : timing->hs_rqst;
+	u32 prep_dly = clk_ln ? timing->hs_prep_dly_ckln : timing->hs_prep_dly;
+	u32 halfbyte_en = clk_ln ? timing->hs_halfbyte_en_ckln :
+				   timing->hs_halfbyte_en;
+
+	dsi_phy_write(base + REG_DSI_14nm_PHY_LN_TIMING_CTRL_4(lane_idx),
+		      DSI_14nm_PHY_LN_TIMING_CTRL_4_HS_EXIT(timing->hs_exit));
+	dsi_phy_write(base + REG_DSI_14nm_PHY_LN_TIMING_CTRL_5(lane_idx),
+		      DSI_14nm_PHY_LN_TIMING_CTRL_5_HS_ZERO(zero));
+	dsi_phy_write(base + REG_DSI_14nm_PHY_LN_TIMING_CTRL_6(lane_idx),
+		      DSI_14nm_PHY_LN_TIMING_CTRL_6_HS_PREPARE(prepare));
+	dsi_phy_write(base + REG_DSI_14nm_PHY_LN_TIMING_CTRL_7(lane_idx),
+		      DSI_14nm_PHY_LN_TIMING_CTRL_7_HS_TRAIL(trail));
+	dsi_phy_write(base + REG_DSI_14nm_PHY_LN_TIMING_CTRL_8(lane_idx),
+		      DSI_14nm_PHY_LN_TIMING_CTRL_8_HS_RQST(rqst));
+	dsi_phy_write(base + REG_DSI_14nm_PHY_LN_CFG0(lane_idx),
+		      DSI_14nm_PHY_LN_CFG0_PREPARE_DLY(prep_dly));
+	dsi_phy_write(base + REG_DSI_14nm_PHY_LN_CFG1(lane_idx),
+		      halfbyte_en ? DSI_14nm_PHY_LN_CFG1_HALFBYTECLK_EN : 0);
+	dsi_phy_write(base + REG_DSI_14nm_PHY_LN_TIMING_CTRL_9(lane_idx),
+		      DSI_14nm_PHY_LN_TIMING_CTRL_9_TA_GO(timing->ta_go) |
+		      DSI_14nm_PHY_LN_TIMING_CTRL_9_TA_SURE(timing->ta_sure));
+	dsi_phy_write(base + REG_DSI_14nm_PHY_LN_TIMING_CTRL_10(lane_idx),
+		      DSI_14nm_PHY_LN_TIMING_CTRL_10_TA_GET(timing->ta_get));
+	dsi_phy_write(base + REG_DSI_14nm_PHY_LN_TIMING_CTRL_11(lane_idx),
+		      DSI_14nm_PHY_LN_TIMING_CTRL_11_TRIG3_CMD(0xa0));
+}
+
+static int dsi_14nm_phy_enable(struct msm_dsi_phy *phy, int src_pll_id,
+			       struct msm_dsi_phy_clk_request *clk_req)
+{
+	struct msm_dsi_dphy_timing *timing = &phy->timing;
+	u32 data;
+	int i;
+	int ret;
+	void __iomem *base = phy->base;
+	void __iomem *lane_base = phy->lane_base;
+
+	if (msm_dsi_dphy_timing_calc_v2(timing, clk_req)) {
+		dev_err(&phy->pdev->dev,
+			"%s: D-PHY timing calculation failed\n", __func__);
+		return -EINVAL;
+	}
+
+	data = 0x1c;
+	if (phy->usecase != MSM_DSI_PHY_STANDALONE)
+		data |= DSI_14nm_PHY_CMN_LDO_CNTRL_VREG_CTRL(32);
+	dsi_phy_write(base + REG_DSI_14nm_PHY_CMN_LDO_CNTRL, data);
+
+	dsi_phy_write(base + REG_DSI_14nm_PHY_CMN_GLBL_TEST_CTRL, 0x1);
+
+	/* 4 data lanes + 1 clk lane configuration */
+	for (i = 0; i < 5; i++) {
+		dsi_phy_write(lane_base + REG_DSI_14nm_PHY_LN_VREG_CNTRL(i),
+			      0x1d);
+
+		dsi_phy_write(lane_base +
+			      REG_DSI_14nm_PHY_LN_STRENGTH_CTRL_0(i), 0xff);
+		dsi_phy_write(lane_base +
+			      REG_DSI_14nm_PHY_LN_STRENGTH_CTRL_1(i),
+			      (i == PHY_14NM_CKLN_IDX) ? 0x00 : 0x06);
+
+		dsi_phy_write(lane_base + REG_DSI_14nm_PHY_LN_CFG3(i),
+			      (i == PHY_14NM_CKLN_IDX) ? 0x8f : 0x0f);
+		dsi_phy_write(lane_base + REG_DSI_14nm_PHY_LN_CFG2(i), 0x10);
+		dsi_phy_write(lane_base + REG_DSI_14nm_PHY_LN_TEST_DATAPATH(i),
+			      0);
+		dsi_phy_write(lane_base + REG_DSI_14nm_PHY_LN_TEST_STR(i),
+			      0x88);
+
+		dsi_14nm_dphy_set_timing(phy, timing, i);
+	}
+
+	/* Make sure PLL is not start */
+	dsi_phy_write(base + REG_DSI_14nm_PHY_CMN_PLL_CNTRL, 0x00);
+
+	wmb(); /* make sure everything is written before reset and enable */
+
+	/* reset digital block */
+	dsi_phy_write(base + REG_DSI_14nm_PHY_CMN_CTRL_1, 0x80);
+	wmb(); /* ensure reset is asserted */
+	udelay(100);
+	dsi_phy_write(base + REG_DSI_14nm_PHY_CMN_CTRL_1, 0x00);
+
+	msm_dsi_phy_set_src_pll(phy, src_pll_id,
+				REG_DSI_14nm_PHY_CMN_GLBL_TEST_CTRL,
+				DSI_14nm_PHY_CMN_GLBL_TEST_CTRL_BITCLK_HS_SEL);
+
+	ret = msm_dsi_pll_set_usecase(phy->pll, phy->usecase);
+	if (ret) {
+		dev_err(&phy->pdev->dev, "%s: set pll usecase failed, %d\n",
+			__func__, ret);
+		return ret;
+	}
+
+	/* Remove power down from PLL and all lanes */
+	dsi_phy_write(base + REG_DSI_14nm_PHY_CMN_CTRL_0, 0xff);
+
+	return 0;
+}
+
+static void dsi_14nm_phy_disable(struct msm_dsi_phy *phy)
+{
+	dsi_phy_write(phy->base + REG_DSI_14nm_PHY_CMN_GLBL_TEST_CTRL, 0);
+	dsi_phy_write(phy->base + REG_DSI_14nm_PHY_CMN_CTRL_0, 0);
+
+	/* ensure that the phy is completely disabled */
+	wmb();
+}
+
+static int dsi_14nm_phy_init(struct msm_dsi_phy *phy)
+{
+	struct platform_device *pdev = phy->pdev;
+
+	phy->lane_base = msm_ioremap(pdev, "dsi_phy_lane",
+				"DSI_PHY_LANE");
+	if (IS_ERR(phy->lane_base)) {
+		dev_err(&pdev->dev, "%s: failed to map phy lane base\n",
+			__func__);
+		return -ENOMEM;
+	}
+
+	return 0;
+}
+
+const struct msm_dsi_phy_cfg dsi_phy_14nm_cfgs = {
+	.type = MSM_DSI_PHY_14NM,
+	.src_pll_truthtable = { {false, false}, {true, false} },
+	.reg_cfg = {
+		.num = 1,
+		.regs = {
+			{"vcca", 17000, 32},
+		},
+	},
+	.ops = {
+		.enable = dsi_14nm_phy_enable,
+		.disable = dsi_14nm_phy_disable,
+		.init = dsi_14nm_phy_init,
+	},
+	.io_start = { 0x994400, 0x996400 },
+	.num_dsi_phy = 2,
+};

drivers/gpu/drm/msm/dsi/pll/dsi_pll.c

@@ -140,6 +140,15 @@ int msm_dsi_pll_restore_state(struct msm_dsi_pll *pll)
 	return 0;
 }
 
+int msm_dsi_pll_set_usecase(struct msm_dsi_pll *pll,
+			    enum msm_dsi_phy_usecase uc)
+{
+	if (pll->set_usecase)
+		return pll->set_usecase(pll, uc);
+
+	return 0;
+}
+
 struct msm_dsi_pll *msm_dsi_pll_init(struct platform_device *pdev,
 			enum msm_dsi_phy_type type, int id)
 {
@@ -154,6 +163,9 @@ struct msm_dsi_pll *msm_dsi_pll_init(struct platform_device *pdev,
 	case MSM_DSI_PHY_28NM_8960:
 		pll = msm_dsi_pll_28nm_8960_init(pdev, id);
 		break;
+	case MSM_DSI_PHY_14NM:
+		pll = msm_dsi_pll_14nm_init(pdev, id);
+		break;
 	default:
 		pll = ERR_PTR(-ENXIO);
 		break;

drivers/gpu/drm/msm/dsi/pll/dsi_pll.h

@@ -41,6 +41,8 @@ struct msm_dsi_pll {
 	void (*destroy)(struct msm_dsi_pll *pll);
 	void (*save_state)(struct msm_dsi_pll *pll);
 	int (*restore_state)(struct msm_dsi_pll *pll);
+	int (*set_usecase)(struct msm_dsi_pll *pll,
+			   enum msm_dsi_phy_usecase uc);
 };
 
 #define hw_clk_to_pll(x) container_of(x, struct msm_dsi_pll, clk_hw)
@@ -104,5 +106,14 @@ static inline struct msm_dsi_pll *msm_dsi_pll_28nm_8960_init(
 }
 #endif
 
+#ifdef CONFIG_DRM_MSM_DSI_14NM_PHY
+struct msm_dsi_pll *msm_dsi_pll_14nm_init(struct platform_device *pdev, int id);
+#else
+static inline struct msm_dsi_pll *
+msm_dsi_pll_14nm_init(struct platform_device *pdev, int id)
+{
+	return ERR_PTR(-ENODEV);
+}
+#endif
 #endif /* __DSI_PLL_H__ */