drm/mediatek: Add DSI sub driver

This patch add a drm encoder/connector driver for the MIPI DSI function
block of the Mediatek display subsystem and a phy driver for the MIPI TX
D-PHY control module.
Signed-off-by: NJitao Shi <jitao.shi@mediatek.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

drivers/gpu/drm/mediatek/Kconfig

@@ -4,6 +4,8 @@ config DRM_MEDIATEK
 	depends on ARCH_MEDIATEK || (ARM && COMPILE_TEST)
 	select DRM_GEM_CMA_HELPER
 	select DRM_KMS_HELPER
+	select DRM_MIPI_DSI
+	select DRM_PANEL
 	select IOMMU_DMA
 	select MEMORY
 	select MTK_SMI

drivers/gpu/drm/mediatek/Makefile

@@ -6,6 +6,8 @@ mediatek-drm-y := mtk_disp_ovl.o \
 		  mtk_drm_drv.o \
 		  mtk_drm_fb.o \
 		  mtk_drm_gem.o \
-		  mtk_drm_plane.o
+		  mtk_drm_plane.o \
+		  mtk_dsi.o \
+		  mtk_mipi_tx.o
 
 obj-$(CONFIG_DRM_MEDIATEK) += mediatek-drm.o

drivers/gpu/drm/mediatek/mtk_drm_drv.c

@@ -523,6 +523,8 @@ static struct platform_driver * const mtk_drm_drivers[] = {
 	&mtk_disp_ovl_driver,
 	&mtk_disp_rdma_driver,
 	&mtk_drm_platform_driver,
+	&mtk_dsi_driver,
+	&mtk_mipi_tx_driver,
 };
 
 static int __init mtk_drm_init(void)

drivers/gpu/drm/mediatek/mtk_drm_drv.h

@@ -53,5 +53,7 @@ struct mtk_drm_private {
 extern struct platform_driver mtk_ddp_driver;
 extern struct platform_driver mtk_disp_ovl_driver;
 extern struct platform_driver mtk_disp_rdma_driver;
+extern struct platform_driver mtk_dsi_driver;
+extern struct platform_driver mtk_mipi_tx_driver;
 
 #endif /* MTK_DRM_DRV_H */

drivers/gpu/drm/mediatek/mtk_mipi_tx.c

+/*
+ * Copyright (c) 2015 MediaTek Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License 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 <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/phy/phy.h>
+
+#define MIPITX_DSI_CON		0x00
+#define RG_DSI_LDOCORE_EN		BIT(0)
+#define RG_DSI_CKG_LDOOUT_EN		BIT(1)
+#define RG_DSI_BCLK_SEL			(3 << 2)
+#define RG_DSI_LD_IDX_SEL		(7 << 4)
+#define RG_DSI_PHYCLK_SEL		(2 << 8)
+#define RG_DSI_DSICLK_FREQ_SEL		BIT(10)
+#define RG_DSI_LPTX_CLMP_EN		BIT(11)
+
+#define MIPITX_DSI_CLOCK_LANE	0x04
+#define MIPITX_DSI_DATA_LANE0	0x08
+#define MIPITX_DSI_DATA_LANE1	0x0c
+#define MIPITX_DSI_DATA_LANE2	0x10
+#define MIPITX_DSI_DATA_LANE3	0x14
+#define RG_DSI_LNTx_LDOOUT_EN		BIT(0)
+#define RG_DSI_LNTx_CKLANE_EN		BIT(1)
+#define RG_DSI_LNTx_LPTX_IPLUS1		BIT(2)
+#define RG_DSI_LNTx_LPTX_IPLUS2		BIT(3)
+#define RG_DSI_LNTx_LPTX_IMINUS		BIT(4)
+#define RG_DSI_LNTx_LPCD_IPLUS		BIT(5)
+#define RG_DSI_LNTx_LPCD_IMINUS		BIT(6)
+#define RG_DSI_LNTx_RT_CODE		(0xf << 8)
+
+#define MIPITX_DSI_TOP_CON	0x40
+#define RG_DSI_LNT_INTR_EN		BIT(0)
+#define RG_DSI_LNT_HS_BIAS_EN		BIT(1)
+#define RG_DSI_LNT_IMP_CAL_EN		BIT(2)
+#define RG_DSI_LNT_TESTMODE_EN		BIT(3)
+#define RG_DSI_LNT_IMP_CAL_CODE		(0xf << 4)
+#define RG_DSI_LNT_AIO_SEL		(7 << 8)
+#define RG_DSI_PAD_TIE_LOW_EN		BIT(11)
+#define RG_DSI_DEBUG_INPUT_EN		BIT(12)
+#define RG_DSI_PRESERVE			(7 << 13)
+
+#define MIPITX_DSI_BG_CON	0x44
+#define RG_DSI_BG_CORE_EN		BIT(0)
+#define RG_DSI_BG_CKEN			BIT(1)
+#define RG_DSI_BG_DIV			(0x3 << 2)
+#define RG_DSI_BG_FAST_CHARGE		BIT(4)
+#define RG_DSI_VOUT_MSK			(0x3ffff << 5)
+#define RG_DSI_V12_SEL			(7 << 5)
+#define RG_DSI_V10_SEL			(7 << 8)
+#define RG_DSI_V072_SEL			(7 << 11)
+#define RG_DSI_V04_SEL			(7 << 14)
+#define RG_DSI_V032_SEL			(7 << 17)
+#define RG_DSI_V02_SEL			(7 << 20)
+#define RG_DSI_BG_R1_TRIM		(0xf << 24)
+#define RG_DSI_BG_R2_TRIM		(0xf << 28)
+
+#define MIPITX_DSI_PLL_CON0	0x50
+#define RG_DSI_MPPLL_PLL_EN		BIT(0)
+#define RG_DSI_MPPLL_DIV_MSK		(0x1ff << 1)
+#define RG_DSI_MPPLL_PREDIV		(3 << 1)
+#define RG_DSI_MPPLL_TXDIV0		(3 << 3)
+#define RG_DSI_MPPLL_TXDIV1		(3 << 5)
+#define RG_DSI_MPPLL_POSDIV		(7 << 7)
+#define RG_DSI_MPPLL_MONVC_EN		BIT(10)
+#define RG_DSI_MPPLL_MONREF_EN		BIT(11)
+#define RG_DSI_MPPLL_VOD_EN		BIT(12)
+
+#define MIPITX_DSI_PLL_CON1	0x54
+#define RG_DSI_MPPLL_SDM_FRA_EN		BIT(0)
+#define RG_DSI_MPPLL_SDM_SSC_PH_INIT	BIT(1)
+#define RG_DSI_MPPLL_SDM_SSC_EN		BIT(2)
+#define RG_DSI_MPPLL_SDM_SSC_PRD	(0xffff << 16)
+
+#define MIPITX_DSI_PLL_CON2	0x58
+
+#define MIPITX_DSI_PLL_PWR	0x68
+#define RG_DSI_MPPLL_SDM_PWR_ON		BIT(0)
+#define RG_DSI_MPPLL_SDM_ISO_EN		BIT(1)
+#define RG_DSI_MPPLL_SDM_PWR_ACK	BIT(8)
+
+#define MIPITX_DSI_SW_CTRL	0x80
+#define SW_CTRL_EN			BIT(0)
+
+#define MIPITX_DSI_SW_CTRL_CON0	0x84
+#define SW_LNTC_LPTX_PRE_OE		BIT(0)
+#define SW_LNTC_LPTX_OE			BIT(1)
+#define SW_LNTC_LPTX_P			BIT(2)
+#define SW_LNTC_LPTX_N			BIT(3)
+#define SW_LNTC_HSTX_PRE_OE		BIT(4)
+#define SW_LNTC_HSTX_OE			BIT(5)
+#define SW_LNTC_HSTX_ZEROCLK		BIT(6)
+#define SW_LNT0_LPTX_PRE_OE		BIT(7)
+#define SW_LNT0_LPTX_OE			BIT(8)
+#define SW_LNT0_LPTX_P			BIT(9)
+#define SW_LNT0_LPTX_N			BIT(10)
+#define SW_LNT0_HSTX_PRE_OE		BIT(11)
+#define SW_LNT0_HSTX_OE			BIT(12)
+#define SW_LNT0_LPRX_EN			BIT(13)
+#define SW_LNT1_LPTX_PRE_OE		BIT(14)
+#define SW_LNT1_LPTX_OE			BIT(15)
+#define SW_LNT1_LPTX_P			BIT(16)
+#define SW_LNT1_LPTX_N			BIT(17)
+#define SW_LNT1_HSTX_PRE_OE		BIT(18)
+#define SW_LNT1_HSTX_OE			BIT(19)
+#define SW_LNT2_LPTX_PRE_OE		BIT(20)
+#define SW_LNT2_LPTX_OE			BIT(21)
+#define SW_LNT2_LPTX_P			BIT(22)
+#define SW_LNT2_LPTX_N			BIT(23)
+#define SW_LNT2_HSTX_PRE_OE		BIT(24)
+#define SW_LNT2_HSTX_OE			BIT(25)
+
+struct mtk_mipi_tx {
+	struct device *dev;
+	void __iomem *regs;
+	unsigned int data_rate;
+	struct clk_hw pll_hw;
+	struct clk *pll;
+};
+
+static inline struct mtk_mipi_tx *mtk_mipi_tx_from_clk_hw(struct clk_hw *hw)
+{
+	return container_of(hw, struct mtk_mipi_tx, pll_hw);
+}
+
+static void mtk_mipi_tx_clear_bits(struct mtk_mipi_tx *mipi_tx, u32 offset,
+				   u32 bits)
+{
+	u32 temp = readl(mipi_tx->regs + offset);
+
+	writel(temp & ~bits, mipi_tx->regs + offset);
+}
+
+static void mtk_mipi_tx_set_bits(struct mtk_mipi_tx *mipi_tx, u32 offset,
+				 u32 bits)
+{
+	u32 temp = readl(mipi_tx->regs + offset);
+
+	writel(temp | bits, mipi_tx->regs + offset);
+}
+
+static void mtk_mipi_tx_update_bits(struct mtk_mipi_tx *mipi_tx, u32 offset,
+				    u32 mask, u32 data)
+{
+	u32 temp = readl(mipi_tx->regs + offset);
+
+	writel((temp & ~mask) | (data & mask), mipi_tx->regs + offset);
+}
+
+static int mtk_mipi_tx_pll_prepare(struct clk_hw *hw)
+{
+	struct mtk_mipi_tx *mipi_tx = mtk_mipi_tx_from_clk_hw(hw);
+	unsigned int txdiv, txdiv0, txdiv1;
+	u64 pcw;
+
+	dev_dbg(mipi_tx->dev, "prepare: %u Hz\n", mipi_tx->data_rate);
+
+	if (mipi_tx->data_rate >= 500000000) {
+		txdiv = 1;
+		txdiv0 = 0;
+		txdiv1 = 0;
+	} else if (mipi_tx->data_rate >= 250000000) {
+		txdiv = 2;
+		txdiv0 = 1;
+		txdiv1 = 0;
+	} else if (mipi_tx->data_rate >= 125000000) {
+		txdiv = 4;
+		txdiv0 = 2;
+		txdiv1 = 0;
+	} else if (mipi_tx->data_rate > 62000000) {
+		txdiv = 8;
+		txdiv0 = 2;
+		txdiv1 = 1;
+	} else if (mipi_tx->data_rate >= 50000000) {
+		txdiv = 16;
+		txdiv0 = 2;
+		txdiv1 = 2;
+	} else {
+		return -EINVAL;
+	}
+
+	mtk_mipi_tx_update_bits(mipi_tx, MIPITX_DSI_BG_CON,
+				RG_DSI_VOUT_MSK |
+				RG_DSI_BG_CKEN | RG_DSI_BG_CORE_EN,
+				(4 << 20) | (4 << 17) | (4 << 14) |
+				(4 << 11) | (4 << 8) | (4 << 5) |
+				RG_DSI_BG_CKEN | RG_DSI_BG_CORE_EN);
+
+	usleep_range(30, 100);
+
+	mtk_mipi_tx_update_bits(mipi_tx, MIPITX_DSI_TOP_CON,
+				RG_DSI_LNT_IMP_CAL_CODE | RG_DSI_LNT_HS_BIAS_EN,
+				(8 << 4) | RG_DSI_LNT_HS_BIAS_EN);
+
+	mtk_mipi_tx_set_bits(mipi_tx, MIPITX_DSI_CON,
+			     RG_DSI_CKG_LDOOUT_EN | RG_DSI_LDOCORE_EN);
+
+	mtk_mipi_tx_update_bits(mipi_tx, MIPITX_DSI_PLL_PWR,
+				RG_DSI_MPPLL_SDM_PWR_ON |
+				RG_DSI_MPPLL_SDM_ISO_EN,
+				RG_DSI_MPPLL_SDM_PWR_ON);
+
+	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_PLL_CON0,
+			       RG_DSI_MPPLL_PLL_EN);
+
+	mtk_mipi_tx_update_bits(mipi_tx, MIPITX_DSI_PLL_CON0,
+				RG_DSI_MPPLL_TXDIV0 | RG_DSI_MPPLL_TXDIV1 |
+				RG_DSI_MPPLL_PREDIV,
+				(txdiv0 << 3) | (txdiv1 << 5));
+
+	/*
+	 * PLL PCW config
+	 * PCW bit 24~30 = integer part of pcw
+	 * PCW bit 0~23 = fractional part of pcw
+	 * pcw = data_Rate*4*txdiv/(Ref_clk*2);
+	 * Post DIV =4, so need data_Rate*4
+	 * Ref_clk is 26MHz
+	 */
+	pcw = div_u64(((u64)mipi_tx->data_rate * 2 * txdiv) << 24,
+		      26000000);
+	writel(pcw, mipi_tx->regs + MIPITX_DSI_PLL_CON2);
+
+	mtk_mipi_tx_set_bits(mipi_tx, MIPITX_DSI_PLL_CON1,
+			     RG_DSI_MPPLL_SDM_FRA_EN);
+
+	mtk_mipi_tx_set_bits(mipi_tx, MIPITX_DSI_PLL_CON0, RG_DSI_MPPLL_PLL_EN);
+
+	usleep_range(20, 100);
+
+	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_PLL_CON1,
+			       RG_DSI_MPPLL_SDM_SSC_EN);
+
+	return 0;
+}
+
+static void mtk_mipi_tx_pll_unprepare(struct clk_hw *hw)
+{
+	struct mtk_mipi_tx *mipi_tx = mtk_mipi_tx_from_clk_hw(hw);
+
+	dev_dbg(mipi_tx->dev, "unprepare\n");
+
+	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_PLL_CON0,
+			       RG_DSI_MPPLL_PLL_EN);
+
+	mtk_mipi_tx_update_bits(mipi_tx, MIPITX_DSI_PLL_PWR,
+				RG_DSI_MPPLL_SDM_ISO_EN |
+				RG_DSI_MPPLL_SDM_PWR_ON,
+				RG_DSI_MPPLL_SDM_ISO_EN);
+
+	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_TOP_CON,
+			       RG_DSI_LNT_HS_BIAS_EN);
+
+	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_CON,
+			       RG_DSI_CKG_LDOOUT_EN | RG_DSI_LDOCORE_EN);
+
+	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_BG_CON,
+			       RG_DSI_BG_CKEN | RG_DSI_BG_CORE_EN);
+
+	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_PLL_CON0,
+			       RG_DSI_MPPLL_DIV_MSK);
+}
+
+static long mtk_mipi_tx_pll_round_rate(struct clk_hw *hw, unsigned long rate,
+				       unsigned long *prate)
+{
+	return clamp_val(rate, 50000000, 1250000000);
+}
+
+static int mtk_mipi_tx_pll_set_rate(struct clk_hw *hw, unsigned long rate,
+				    unsigned long parent_rate)
+{
+	struct mtk_mipi_tx *mipi_tx = mtk_mipi_tx_from_clk_hw(hw);
+
+	dev_dbg(mipi_tx->dev, "set rate: %lu Hz\n", rate);
+
+	mipi_tx->data_rate = rate;
+
+	return 0;
+}
+
+static unsigned long mtk_mipi_tx_pll_recalc_rate(struct clk_hw *hw,
+						 unsigned long parent_rate)
+{
+	struct mtk_mipi_tx *mipi_tx = mtk_mipi_tx_from_clk_hw(hw);
+
+	return mipi_tx->data_rate;
+}
+
+static const struct clk_ops mtk_mipi_tx_pll_ops = {
+	.prepare = mtk_mipi_tx_pll_prepare,
+	.unprepare = mtk_mipi_tx_pll_unprepare,
+	.round_rate = mtk_mipi_tx_pll_round_rate,
+	.set_rate = mtk_mipi_tx_pll_set_rate,
+	.recalc_rate = mtk_mipi_tx_pll_recalc_rate,
+};
+
+static int mtk_mipi_tx_power_on_signal(struct phy *phy)
+{
+	struct mtk_mipi_tx *mipi_tx = phy_get_drvdata(phy);
+	unsigned int reg;
+
+	for (reg = MIPITX_DSI_CLOCK_LANE;
+	     reg <= MIPITX_DSI_DATA_LANE3; reg += 4)
+		mtk_mipi_tx_set_bits(mipi_tx, reg, RG_DSI_LNTx_LDOOUT_EN);
+
+	mtk_mipi_tx_clear_bits(mipi_tx, MIPITX_DSI_TOP_CON,
+			       RG_DSI_PAD_TIE_LOW_EN);
+
+	return 0;
+}
+
+static int mtk_mipi_tx_power_on(struct phy *phy)
+{
+	struct mtk_mipi_tx *mipi_tx = phy_get_drvdata(phy);
+	int ret;
+
+	/* Power up core and enable PLL */
+	ret = clk_prepare_enable(mipi_tx->pll);
+	if (ret < 0)
+		return ret;
+
+	/* Enable DSI Lane LDO outputs, disable pad tie low */
+	mtk_mipi_tx_power_on_signal(phy);
+
+	return 0;
+}
+
+static void mtk_mipi_tx_power_off_signal(struct phy *phy)
+{
+	struct mtk_mipi_tx *mipi_tx = phy_get_drvdata(phy);
+	unsigned int reg;
+
+	mtk_mipi_tx_set_bits(mipi_tx, MIPITX_DSI_TOP_CON,
+			     RG_DSI_PAD_TIE_LOW_EN);
+
+	for (reg = MIPITX_DSI_CLOCK_LANE;
+	     reg <= MIPITX_DSI_DATA_LANE3; reg += 4)
+		mtk_mipi_tx_clear_bits(mipi_tx, reg, RG_DSI_LNTx_LDOOUT_EN);
+}
+
+static int mtk_mipi_tx_power_off(struct phy *phy)
+{
+	struct mtk_mipi_tx *mipi_tx = phy_get_drvdata(phy);
+
+	/* Enable pad tie low, disable DSI Lane LDO outputs */
+	mtk_mipi_tx_power_off_signal(phy);
+
+	/* Disable PLL and power down core */
+	clk_disable_unprepare(mipi_tx->pll);
+
+	return 0;
+}
+
+static const struct phy_ops mtk_mipi_tx_ops = {
+	.power_on = mtk_mipi_tx_power_on,
+	.power_off = mtk_mipi_tx_power_off,
+	.owner = THIS_MODULE,
+};
+
+static int mtk_mipi_tx_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct mtk_mipi_tx *mipi_tx;
+	struct resource *mem;
+	struct clk *ref_clk;
+	const char *ref_clk_name;
+	struct clk_init_data clk_init = {
+		.ops = &mtk_mipi_tx_pll_ops,
+		.num_parents = 1,
+		.parent_names = (const char * const *)&ref_clk_name,
+		.flags = CLK_SET_RATE_GATE,
+	};
+	struct phy *phy;
+	struct phy_provider *phy_provider;
+	int ret;
+
+	mipi_tx = devm_kzalloc(dev, sizeof(*mipi_tx), GFP_KERNEL);
+	if (!mipi_tx)
+		return -ENOMEM;
+
+	mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	mipi_tx->regs = devm_ioremap_resource(dev, mem);
+	if (IS_ERR(mipi_tx->regs)) {
+		ret = PTR_ERR(mipi_tx->regs);
+		dev_err(dev, "Failed to get memory resource: %d\n", ret);
+		return ret;
+	}
+
+	ref_clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(ref_clk)) {
+		ret = PTR_ERR(ref_clk);
+		dev_err(dev, "Failed to get reference clock: %d\n", ret);
+		return ret;
+	}
+	ref_clk_name = __clk_get_name(ref_clk);
+
+	ret = of_property_read_string(dev->of_node, "clock-output-names",
+				      &clk_init.name);
+	if (ret < 0) {
+		dev_err(dev, "Failed to read clock-output-names: %d\n", ret);
+		return ret;
+	}
+
+	mipi_tx->pll_hw.init = &clk_init;
+	mipi_tx->pll = devm_clk_register(dev, &mipi_tx->pll_hw);
+	if (IS_ERR(mipi_tx->pll)) {
+		ret = PTR_ERR(mipi_tx->pll);
+		dev_err(dev, "Failed to register PLL: %d\n", ret);
+		return ret;
+	}
+
+	phy = devm_phy_create(dev, NULL, &mtk_mipi_tx_ops);
+	if (IS_ERR(phy)) {
+		ret = PTR_ERR(phy);
+		dev_err(dev, "Failed to create MIPI D-PHY: %d\n", ret);
+		return ret;
+	}
+	phy_set_drvdata(phy, mipi_tx);
+
+	phy_provider = devm_of_phy_provider_register(dev, of_phy_simple_xlate);
+	if (IS_ERR(phy)) {
+		ret = PTR_ERR(phy_provider);
+		return ret;
+	}
+
+	mipi_tx->dev = dev;
+
+	return of_clk_add_provider(dev->of_node, of_clk_src_simple_get,
+				   mipi_tx->pll);
+}
+
+static int mtk_mipi_tx_remove(struct platform_device *pdev)
+{
+	of_clk_del_provider(pdev->dev.of_node);
+	return 0;
+}
+
+static const struct of_device_id mtk_mipi_tx_match[] = {
+	{ .compatible = "mediatek,mt8173-mipi-tx", },
+	{},
+};
+
+struct platform_driver mtk_mipi_tx_driver = {
+	.probe = mtk_mipi_tx_probe,
+	.remove = mtk_mipi_tx_remove,
+	.driver = {
+		.name = "mediatek-mipi-tx",
+		.of_match_table = mtk_mipi_tx_match,
+	},
+};