drm/sun4i: Add Allwinner A31 MIPI-DSI controller support

Most of the Allwinner SoCs since the A31 share the same MIPI-DSI
controller.

While that controller is mostly undocumented, the code is out there and has
been cleaned up in order to be integrated into DRM. However, there's still
some dark areas that are a bit unclear about how the block exactly
operates.

Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Link: https://patchwork.freedesktop.org/patch/msgid/ad9e6224fced87c0889ddd2765d1942610061f72.1522835818.git-series.maxime.ripard@bootlin.com

drivers/gpu/drm/sun4i/Kconfig

@@ -40,6 +40,16 @@ config DRM_SUN4I_BACKEND
 	  do some alpha blending and feed graphics to TCON. If M is
 	  selected the module will be called sun4i-backend.
 
+config DRM_SUN6I_DSI
+	tristate "Allwinner A31 MIPI-DSI Controller Support"
+	default MACH_SUN8I
+	select CRC_CCITT
+	select DRM_MIPI_DSI
+	help
+	  Choose this option if you want have an Allwinner SoC with
+	  MIPI-DSI support. If M is selected the module will be called
+	  sun6i-dsi
+
 config DRM_SUN8I_DW_HDMI
 	tristate "Support for Allwinner version of DesignWare HDMI"
 	depends on DRM_SUN4I

drivers/gpu/drm/sun4i/Makefile

@@ -24,6 +24,9 @@ sun4i-tcon-y			+= sun4i_lvds.o
 sun4i-tcon-y			+= sun4i_tcon.o
 sun4i-tcon-y			+= sun4i_rgb.o
 
+sun6i-dsi-y			+= sun6i_mipi_dphy.o
+sun6i-dsi-y			+= sun6i_mipi_dsi.o
+
 obj-$(CONFIG_DRM_SUN4I)		+= sun4i-drm.o
 obj-$(CONFIG_DRM_SUN4I)		+= sun4i-tcon.o
 obj-$(CONFIG_DRM_SUN4I)		+= sun4i_tv.o
@@ -31,5 +34,6 @@ obj-$(CONFIG_DRM_SUN4I)		+= sun6i_drc.o
 
 obj-$(CONFIG_DRM_SUN4I_BACKEND)	+= sun4i-backend.o sun4i-frontend.o
 obj-$(CONFIG_DRM_SUN4I_HDMI)	+= sun4i-drm-hdmi.o
+obj-$(CONFIG_DRM_SUN6I_DSI)	+= sun6i-dsi.o
 obj-$(CONFIG_DRM_SUN8I_DW_HDMI)	+= sun8i-drm-hdmi.o
 obj-$(CONFIG_DRM_SUN8I_MIXER)	+= sun8i-mixer.o

drivers/gpu/drm/sun4i/sun6i_mipi_dphy.c

@@ -0,0 +1,292 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2016 Allwinnertech Co., Ltd.
+ * Copyright (C) 2017-2018 Bootlin
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ */
+
+#include <linux/bitops.h>
+#include <linux/clk.h>
+#include <linux/of_address.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+#include "sun6i_mipi_dsi.h"
+
+#define SUN6I_DPHY_GCTL_REG		0x00
+#define SUN6I_DPHY_GCTL_LANE_NUM(n)		((((n) - 1) & 3) << 4)
+#define SUN6I_DPHY_GCTL_EN			BIT(0)
+
+#define SUN6I_DPHY_TX_CTL_REG		0x04
+#define SUN6I_DPHY_TX_CTL_HS_TX_CLK_CONT	BIT(28)
+
+#define SUN6I_DPHY_TX_TIME0_REG		0x10
+#define SUN6I_DPHY_TX_TIME0_HS_TRAIL(n)		(((n) & 0xff) << 24)
+#define SUN6I_DPHY_TX_TIME0_HS_PREPARE(n)	(((n) & 0xff) << 16)
+#define SUN6I_DPHY_TX_TIME0_LP_CLK_DIV(n)	((n) & 0xff)
+
+#define SUN6I_DPHY_TX_TIME1_REG		0x14
+#define SUN6I_DPHY_TX_TIME1_CLK_POST(n)		(((n) & 0xff) << 24)
+#define SUN6I_DPHY_TX_TIME1_CLK_PRE(n)		(((n) & 0xff) << 16)
+#define SUN6I_DPHY_TX_TIME1_CLK_ZERO(n)		(((n) & 0xff) << 8)
+#define SUN6I_DPHY_TX_TIME1_CLK_PREPARE(n)	((n) & 0xff)
+
+#define SUN6I_DPHY_TX_TIME2_REG		0x18
+#define SUN6I_DPHY_TX_TIME2_CLK_TRAIL(n)	((n) & 0xff)
+
+#define SUN6I_DPHY_TX_TIME3_REG		0x1c
+
+#define SUN6I_DPHY_TX_TIME4_REG		0x20
+#define SUN6I_DPHY_TX_TIME4_HS_TX_ANA1(n)	(((n) & 0xff) << 8)
+#define SUN6I_DPHY_TX_TIME4_HS_TX_ANA0(n)	((n) & 0xff)
+
+#define SUN6I_DPHY_ANA0_REG		0x4c
+#define SUN6I_DPHY_ANA0_REG_PWS			BIT(31)
+#define SUN6I_DPHY_ANA0_REG_DMPC		BIT(28)
+#define SUN6I_DPHY_ANA0_REG_DMPD(n)		(((n) & 0xf) << 24)
+#define SUN6I_DPHY_ANA0_REG_SLV(n)		(((n) & 7) << 12)
+#define SUN6I_DPHY_ANA0_REG_DEN(n)		(((n) & 0xf) << 8)
+
+#define SUN6I_DPHY_ANA1_REG		0x50
+#define SUN6I_DPHY_ANA1_REG_VTTMODE		BIT(31)
+#define SUN6I_DPHY_ANA1_REG_CSMPS(n)		(((n) & 3) << 28)
+#define SUN6I_DPHY_ANA1_REG_SVTT(n)		(((n) & 0xf) << 24)
+
+#define SUN6I_DPHY_ANA2_REG		0x54
+#define SUN6I_DPHY_ANA2_EN_P2S_CPU(n)		(((n) & 0xf) << 24)
+#define SUN6I_DPHY_ANA2_EN_P2S_CPU_MASK		GENMASK(27, 24)
+#define SUN6I_DPHY_ANA2_EN_CK_CPU		BIT(4)
+#define SUN6I_DPHY_ANA2_REG_ENIB		BIT(1)
+
+#define SUN6I_DPHY_ANA3_REG		0x58
+#define SUN6I_DPHY_ANA3_EN_VTTD(n)		(((n) & 0xf) << 28)
+#define SUN6I_DPHY_ANA3_EN_VTTD_MASK		GENMASK(31, 28)
+#define SUN6I_DPHY_ANA3_EN_VTTC			BIT(27)
+#define SUN6I_DPHY_ANA3_EN_DIV			BIT(26)
+#define SUN6I_DPHY_ANA3_EN_LDOC			BIT(25)
+#define SUN6I_DPHY_ANA3_EN_LDOD			BIT(24)
+#define SUN6I_DPHY_ANA3_EN_LDOR			BIT(18)
+
+#define SUN6I_DPHY_ANA4_REG		0x5c
+#define SUN6I_DPHY_ANA4_REG_DMPLVC		BIT(24)
+#define SUN6I_DPHY_ANA4_REG_DMPLVD(n)		(((n) & 0xf) << 20)
+#define SUN6I_DPHY_ANA4_REG_CKDV(n)		(((n) & 0x1f) << 12)
+#define SUN6I_DPHY_ANA4_REG_TMSC(n)		(((n) & 3) << 10)
+#define SUN6I_DPHY_ANA4_REG_TMSD(n)		(((n) & 3) << 8)
+#define SUN6I_DPHY_ANA4_REG_TXDNSC(n)		(((n) & 3) << 6)
+#define SUN6I_DPHY_ANA4_REG_TXDNSD(n)		(((n) & 3) << 4)
+#define SUN6I_DPHY_ANA4_REG_TXPUSC(n)		(((n) & 3) << 2)
+#define SUN6I_DPHY_ANA4_REG_TXPUSD(n)		((n) & 3)
+
+#define SUN6I_DPHY_DBG5_REG		0xf4
+
+int sun6i_dphy_init(struct sun6i_dphy *dphy, unsigned int lanes)
+{
+	reset_control_deassert(dphy->reset);
+	clk_prepare_enable(dphy->mod_clk);
+	clk_set_rate_exclusive(dphy->mod_clk, 150000000);
+
+	regmap_write(dphy->regs, SUN6I_DPHY_TX_CTL_REG,
+		     SUN6I_DPHY_TX_CTL_HS_TX_CLK_CONT);
+
+	regmap_write(dphy->regs, SUN6I_DPHY_TX_TIME0_REG,
+		     SUN6I_DPHY_TX_TIME0_LP_CLK_DIV(14) |
+		     SUN6I_DPHY_TX_TIME0_HS_PREPARE(6) |
+		     SUN6I_DPHY_TX_TIME0_HS_TRAIL(10));
+
+	regmap_write(dphy->regs, SUN6I_DPHY_TX_TIME1_REG,
+		     SUN6I_DPHY_TX_TIME1_CLK_PREPARE(7) |
+		     SUN6I_DPHY_TX_TIME1_CLK_ZERO(50) |
+		     SUN6I_DPHY_TX_TIME1_CLK_PRE(3) |
+		     SUN6I_DPHY_TX_TIME1_CLK_POST(10));
+
+	regmap_write(dphy->regs, SUN6I_DPHY_TX_TIME2_REG,
+		     SUN6I_DPHY_TX_TIME2_CLK_TRAIL(30));
+
+	regmap_write(dphy->regs, SUN6I_DPHY_TX_TIME3_REG, 0);
+
+	regmap_write(dphy->regs, SUN6I_DPHY_TX_TIME4_REG,
+		     SUN6I_DPHY_TX_TIME4_HS_TX_ANA0(3) |
+		     SUN6I_DPHY_TX_TIME4_HS_TX_ANA1(3));
+
+	regmap_write(dphy->regs, SUN6I_DPHY_GCTL_REG,
+		     SUN6I_DPHY_GCTL_LANE_NUM(lanes) |
+		     SUN6I_DPHY_GCTL_EN);
+
+	return 0;
+}
+
+int sun6i_dphy_power_on(struct sun6i_dphy *dphy, unsigned int lanes)
+{
+	u8 lanes_mask = GENMASK(lanes - 1, 0);
+
+	regmap_write(dphy->regs, SUN6I_DPHY_ANA0_REG,
+		     SUN6I_DPHY_ANA0_REG_PWS |
+		     SUN6I_DPHY_ANA0_REG_DMPC |
+		     SUN6I_DPHY_ANA0_REG_SLV(7) |
+		     SUN6I_DPHY_ANA0_REG_DMPD(lanes_mask) |
+		     SUN6I_DPHY_ANA0_REG_DEN(lanes_mask));
+
+	regmap_write(dphy->regs, SUN6I_DPHY_ANA1_REG,
+		     SUN6I_DPHY_ANA1_REG_CSMPS(1) |
+		     SUN6I_DPHY_ANA1_REG_SVTT(7));
+
+	regmap_write(dphy->regs, SUN6I_DPHY_ANA4_REG,
+		     SUN6I_DPHY_ANA4_REG_CKDV(1) |
+		     SUN6I_DPHY_ANA4_REG_TMSC(1) |
+		     SUN6I_DPHY_ANA4_REG_TMSD(1) |
+		     SUN6I_DPHY_ANA4_REG_TXDNSC(1) |
+		     SUN6I_DPHY_ANA4_REG_TXDNSD(1) |
+		     SUN6I_DPHY_ANA4_REG_TXPUSC(1) |
+		     SUN6I_DPHY_ANA4_REG_TXPUSD(1) |
+		     SUN6I_DPHY_ANA4_REG_DMPLVC |
+		     SUN6I_DPHY_ANA4_REG_DMPLVD(lanes_mask));
+
+	regmap_write(dphy->regs, SUN6I_DPHY_ANA2_REG,
+		     SUN6I_DPHY_ANA2_REG_ENIB);
+	udelay(5);
+
+	regmap_write(dphy->regs, SUN6I_DPHY_ANA3_REG,
+		     SUN6I_DPHY_ANA3_EN_LDOR |
+		     SUN6I_DPHY_ANA3_EN_LDOC |
+		     SUN6I_DPHY_ANA3_EN_LDOD);
+	udelay(1);
+
+	regmap_update_bits(dphy->regs, SUN6I_DPHY_ANA3_REG,
+			   SUN6I_DPHY_ANA3_EN_VTTC |
+			   SUN6I_DPHY_ANA3_EN_VTTD_MASK,
+			   SUN6I_DPHY_ANA3_EN_VTTC |
+			   SUN6I_DPHY_ANA3_EN_VTTD(lanes_mask));
+	udelay(1);
+
+	regmap_update_bits(dphy->regs, SUN6I_DPHY_ANA3_REG,
+			   SUN6I_DPHY_ANA3_EN_DIV,
+			   SUN6I_DPHY_ANA3_EN_DIV);
+	udelay(1);
+
+	regmap_update_bits(dphy->regs, SUN6I_DPHY_ANA2_REG,
+			   SUN6I_DPHY_ANA2_EN_CK_CPU,
+			   SUN6I_DPHY_ANA2_EN_CK_CPU);
+	udelay(1);
+
+	regmap_update_bits(dphy->regs, SUN6I_DPHY_ANA1_REG,
+			   SUN6I_DPHY_ANA1_REG_VTTMODE,
+			   SUN6I_DPHY_ANA1_REG_VTTMODE);
+
+	regmap_update_bits(dphy->regs, SUN6I_DPHY_ANA2_REG,
+			   SUN6I_DPHY_ANA2_EN_P2S_CPU_MASK,
+			   SUN6I_DPHY_ANA2_EN_P2S_CPU(lanes_mask));
+
+	return 0;
+}
+
+int sun6i_dphy_power_off(struct sun6i_dphy *dphy)
+{
+	regmap_update_bits(dphy->regs, SUN6I_DPHY_ANA1_REG,
+			   SUN6I_DPHY_ANA1_REG_VTTMODE, 0);
+
+	return 0;
+}
+
+int sun6i_dphy_exit(struct sun6i_dphy *dphy)
+{
+	clk_rate_exclusive_put(dphy->mod_clk);
+	clk_disable_unprepare(dphy->mod_clk);
+	reset_control_assert(dphy->reset);
+
+	return 0;
+}
+
+static struct regmap_config sun6i_dphy_regmap_config = {
+	.reg_bits	= 32,
+	.val_bits	= 32,
+	.reg_stride	= 4,
+	.max_register	= SUN6I_DPHY_DBG5_REG,
+	.name		= "mipi-dphy",
+};
+
+static const struct of_device_id sun6i_dphy_of_table[] = {
+	{ .compatible = "allwinner,sun6i-a31-mipi-dphy" },
+	{ }
+};
+
+int sun6i_dphy_probe(struct sun6i_dsi *dsi, struct device_node *node)
+{
+	struct sun6i_dphy *dphy;
+	struct resource res;
+	void __iomem *regs;
+	int ret;
+
+	if (!of_match_node(sun6i_dphy_of_table, node)) {
+		dev_err(dsi->dev, "Incompatible D-PHY\n");
+		return -EINVAL;
+	}
+
+	dphy = devm_kzalloc(dsi->dev, sizeof(*dphy), GFP_KERNEL);
+	if (!dphy)
+		return -ENOMEM;
+
+	ret = of_address_to_resource(node, 0, &res);
+	if (ret) {
+		dev_err(dsi->dev, "phy: Couldn't get our resources\n");
+		return ret;
+	}
+
+	regs = devm_ioremap_resource(dsi->dev, &res);
+	if (IS_ERR(regs)) {
+		dev_err(dsi->dev, "Couldn't map the DPHY encoder registers\n");
+		return PTR_ERR(regs);
+	}
+
+	dphy->regs = devm_regmap_init_mmio(dsi->dev, regs,
+					   &sun6i_dphy_regmap_config);
+	if (IS_ERR(dphy->regs)) {
+		dev_err(dsi->dev, "Couldn't create the DPHY encoder regmap\n");
+		return PTR_ERR(dphy->regs);
+	}
+
+	dphy->reset = of_reset_control_get_shared(node, NULL);
+	if (IS_ERR(dphy->reset)) {
+		dev_err(dsi->dev, "Couldn't get our reset line\n");
+		return PTR_ERR(dphy->reset);
+	}
+
+	dphy->bus_clk = of_clk_get_by_name(node, "bus");
+	if (IS_ERR(dphy->bus_clk)) {
+		dev_err(dsi->dev, "Couldn't get the DPHY bus clock\n");
+		ret = PTR_ERR(dphy->bus_clk);
+		goto err_free_reset;
+	}
+	regmap_mmio_attach_clk(dphy->regs, dphy->bus_clk);
+
+	dphy->mod_clk = of_clk_get_by_name(node, "mod");
+	if (IS_ERR(dphy->mod_clk)) {
+		dev_err(dsi->dev, "Couldn't get the DPHY mod clock\n");
+		ret = PTR_ERR(dphy->mod_clk);
+		goto err_free_bus;
+	}
+
+	dsi->dphy = dphy;
+
+	return 0;
+
+err_free_bus:
+	regmap_mmio_detach_clk(dphy->regs);
+	clk_put(dphy->bus_clk);
+err_free_reset:
+	reset_control_put(dphy->reset);
+	return ret;
+}
+
+int sun6i_dphy_remove(struct sun6i_dsi *dsi)
+{
+	struct sun6i_dphy *dphy = dsi->dphy;
+
+	regmap_mmio_detach_clk(dphy->regs);
+	clk_put(dphy->mod_clk);
+	clk_put(dphy->bus_clk);
+	reset_control_put(dphy->reset);
+
+	return 0;
+}

drivers/gpu/drm/sun4i/sun6i_mipi_dsi.h

@@ -0,0 +1,63 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2016 Allwinnertech Co., Ltd.
+ * Copyright (C) 2017-2018 Bootlin
+ *
+ * Maxime Ripard <maxime.ripard@bootlin.com>
+ */
+
+#ifndef _SUN6I_MIPI_DSI_H_
+#define _SUN6I_MIPI_DSI_H_
+
+#include <drm/drm_connector.h>
+#include <drm/drm_encoder.h>
+#include <drm/drm_mipi_dsi.h>
+
+struct sun6i_dphy {
+	struct clk		*bus_clk;
+	struct clk		*mod_clk;
+	struct regmap		*regs;
+	struct reset_control	*reset;
+};
+
+struct sun6i_dsi {
+	struct drm_connector	connector;
+	struct drm_encoder	encoder;
+	struct mipi_dsi_host	host;
+
+	struct clk		*bus_clk;
+	struct clk		*mod_clk;
+	struct regmap		*regs;
+	struct reset_control	*reset;
+	struct sun6i_dphy	*dphy;
+
+	struct device		*dev;
+	struct sun4i_drv	*drv;
+	struct mipi_dsi_device	*device;
+	struct drm_panel	*panel;
+};
+
+static inline struct sun6i_dsi *host_to_sun6i_dsi(struct mipi_dsi_host *host)
+{
+	return container_of(host, struct sun6i_dsi, host);
+};
+
+static inline struct sun6i_dsi *connector_to_sun6i_dsi(struct drm_connector *connector)
+{
+	return container_of(connector, struct sun6i_dsi, connector);
+};
+
+static inline struct sun6i_dsi *encoder_to_sun6i_dsi(const struct drm_encoder *encoder)
+{
+	return container_of(encoder, struct sun6i_dsi, encoder);
+};
+
+int sun6i_dphy_probe(struct sun6i_dsi *dsi, struct device_node *node);
+int sun6i_dphy_remove(struct sun6i_dsi *dsi);
+
+int sun6i_dphy_init(struct sun6i_dphy *dphy, unsigned int lanes);
+int sun6i_dphy_power_on(struct sun6i_dphy *dphy, unsigned int lanes);
+int sun6i_dphy_power_off(struct sun6i_dphy *dphy);
+int sun6i_dphy_exit(struct sun6i_dphy *dphy);
+
+#endif /* _SUN6I_MIPI_DSI_H_ */