dm: Add a dsi host uclass

Display Serial Interface (DSI) host can usefully be modelled
as their own uclass.
DSI defines a serial bus and a communication protocol
between the host and the device (panel, bridge).

Signed-off-by: Yannick Fertré <yannick.fertre@st.com>

arch/sandbox/dts/sandbox.dts

@@ -25,6 +25,11 @@
 		compatible = "google,cros-ec-sandbox";
 	};
 
+	dsi_host: dsi_host {
+		compatible = "sandbox,dsi-host";
+		status = "okay";
+	};
+
 	ethrawbus {
 		compatible = "sandbox,eth-raw-bus";
 		skip-localhost = <0>;
@@ -63,7 +68,6 @@
 		compatible = "sandbox,spi";
 		cs-gpios = <0>, <&gpio_a 0>;
 	};
-
 };
 
 #include "sandbox.dtsi"

arch/sandbox/dts/test.dts

@@ -76,6 +76,10 @@
 		};
 	};
 
+	dsi_host: dsi_host {
+		compatible = "sandbox,dsi-host";
+	};
+
 	a-test {
 		reg = <0 1>;
 		compatible = "denx,u-boot-fdt-test";

configs/sandbox_defconfig

@@ -206,6 +206,7 @@ CONFIG_CONSOLE_ROTATION=y
 CONFIG_CONSOLE_TRUETYPE=y
 CONFIG_CONSOLE_TRUETYPE_CANTORAONE=y
 CONFIG_VIDEO_SANDBOX_SDL=y
+CONFIG_VIDEO_DSI_HOST_SANDBOX=y
 CONFIG_OSD=y
 CONFIG_SANDBOX_OSD=y
 CONFIG_W1=y

drivers/video/Kconfig

@@ -686,6 +686,17 @@ config VIDEO_DW_HDMI
 	  rather requires a SoC-specific glue driver to call it), it
 	  can not be enabled from the configuration menu.
 
+config VIDEO_DSI_HOST_SANDBOX
+	bool "Enable sandbox for dsi host"
+	depends on SANDBOX
+	select VIDEO_MIPI_DSI
+	help
+	  Enable support for sandbox dsi host device used for testing
+	  purposes.
+	  Display Serial Interface (DSI) defines a serial bus and
+	  a communication protocol between the host and the device
+	  (panel, bridge).
+
 config VIDEO_SIMPLE
 	bool "Simple display driver for preconfigured display"
 	help

drivers/video/Makefile

@@ -11,6 +11,7 @@ obj-$(CONFIG_CONSOLE_ROTATION) += console_rotate.o
 obj-$(CONFIG_CONSOLE_TRUETYPE) += console_truetype.o fonts/
 obj-$(CONFIG_DISPLAY) += display-uclass.o
 obj-$(CONFIG_DM_VIDEO) += backlight-uclass.o
+obj-$(CONFIG_VIDEO_MIPI_DSI) += dsi-host-uclass.o
 obj-$(CONFIG_DM_VIDEO) += panel-uclass.o simple_panel.o
 obj-$(CONFIG_DM_VIDEO) += video-uclass.o vidconsole-uclass.o
 obj-$(CONFIG_DM_VIDEO) += video_bmp.o
@@ -58,6 +59,7 @@ obj-$(CONFIG_VIDEO_MVEBU) += mvebu_lcd.o
 obj-$(CONFIG_VIDEO_MX3) += mx3fb.o videomodes.o
 obj-$(CONFIG_VIDEO_MXS) += mxsfb.o videomodes.o
 obj-$(CONFIG_VIDEO_OMAP3) += omap3_dss.o
+obj-$(CONFIG_VIDEO_DSI_HOST_SANDBOX) += sandbox_dsi_host.o
 obj-$(CONFIG_VIDEO_SANDBOX_SDL) += sandbox_sdl.o
 obj-$(CONFIG_VIDEO_SIMPLE) += simplefb.o
 obj-$(CONFIG_VIDEO_TEGRA20) += tegra.o

drivers/video/dsi-host-uclass.c

@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 STMicroelectronics - All Rights Reserved
+ * Author(s): Yannick Fertre <yannick.fertre@st.com> for STMicroelectronics.
+ *
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dsi_host.h>
+
+int dsi_host_init(struct udevice *dev,
+		  struct mipi_dsi_device *device,
+		  struct display_timing *timings,
+		  unsigned int max_data_lanes,
+		  const struct mipi_dsi_phy_ops *phy_ops)
+{
+	struct dsi_host_ops *ops = dsi_host_get_ops(dev);
+
+	if (!ops->init)
+		return -ENOSYS;
+
+	return ops->init(dev, device, timings, max_data_lanes, phy_ops);
+}
+
+int dsi_host_enable(struct udevice *dev)
+{
+	struct dsi_host_ops *ops = dsi_host_get_ops(dev);
+
+	if (!ops->enable)
+		return -ENOSYS;
+
+	return ops->enable(dev);
+}
+
+UCLASS_DRIVER(dsi_host) = {
+	.id		= UCLASS_DSI_HOST,
+	.name		= "dsi_host",
+};

drivers/video/sandbox_dsi_host.c

@@ -0,0 +1,90 @@
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+/*
+ * Copyright (C) 2019, STMicroelectronics - All Rights Reserved
+ */
+
+#include <common.h>
+#include <display.h>
+#include <dm.h>
+#include <dsi_host.h>
+
+/**
+ * struct sandbox_dsi_host_priv - private data for driver
+ * @device: DSI peripheral device
+ * @timing: Display timings
+ * @max_data_lanes: maximum number of data lines
+ * @phy_ops: set of function pointers for performing physical operations
+ */
+struct sandbox_dsi_host_priv {
+	struct mipi_dsi_device *device;
+	struct display_timing *timings;
+	unsigned int max_data_lanes;
+	const struct mipi_dsi_phy_ops *phy_ops;
+};
+
+static int sandbox_dsi_host_init(struct udevice *dev,
+				 struct mipi_dsi_device *device,
+				 struct display_timing *timings,
+				 unsigned int max_data_lanes,
+				 const struct mipi_dsi_phy_ops *phy_ops)
+{
+	struct sandbox_dsi_host_priv *priv = dev_get_priv(dev);
+
+	if (!device)
+		return -1;
+
+	if (!timings)
+		return -2;
+
+	if (max_data_lanes == 0)
+		return -3;
+
+	if (!phy_ops)
+		return -4;
+
+	if (!phy_ops->init || !phy_ops->get_lane_mbps ||
+	    !phy_ops->post_set_mode)
+		return -5;
+
+	priv->max_data_lanes = max_data_lanes;
+	priv->phy_ops = phy_ops;
+	priv->timings = timings;
+	priv->device = device;
+
+	return 0;
+}
+
+static int sandbox_dsi_host_enable(struct udevice *dev)
+{
+	struct sandbox_dsi_host_priv *priv = dev_get_priv(dev);
+	unsigned int lane_mbps;
+	int ret;
+
+	priv->phy_ops->init(priv->device);
+	ret = priv->phy_ops->get_lane_mbps(priv->device, priv->timings, 2,
+					   MIPI_DSI_FMT_RGB888, &lane_mbps);
+	if (ret)
+		return -1;
+
+	priv->phy_ops->post_set_mode(priv->device, MIPI_DSI_MODE_VIDEO);
+
+	return 0;
+}
+
+struct dsi_host_ops sandbox_dsi_host_ops = {
+	.init = sandbox_dsi_host_init,
+	.enable = sandbox_dsi_host_enable,
+};
+
+static const struct udevice_id sandbox_dsi_host_ids[] = {
+	{ .compatible = "sandbox,dsi-host"},
+	{ }
+};
+
+U_BOOT_DRIVER(sandbox_dsi_host) = {
+	.name		      = "sandbox-dsi-host",
+	.id		      = UCLASS_DSI_HOST,
+	.of_match	      = sandbox_dsi_host_ids,
+	.ops		      = &sandbox_dsi_host_ops,
+	.priv_auto_alloc_size = sizeof(struct sandbox_dsi_host_priv),
+};

include/dm/uclass-id.h

@@ -40,6 +40,7 @@ enum uclass_id {
 	UCLASS_CPU,		/* CPU, typically part of an SoC */
 	UCLASS_CROS_EC,		/* Chrome OS EC */
 	UCLASS_DISPLAY,		/* Display (e.g. DisplayPort, HDMI) */
+	UCLASS_DSI_HOST,	/* Display Serial Interface host */
 	UCLASS_DMA,		/* Direct Memory Access */
 	UCLASS_EFI,		/* EFI managed devices */
 	UCLASS_ETH,		/* Ethernet device */

include/dsi_host.h

@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2019 STMicroelectronics - All Rights Reserved
+ * Author(s): Yannick Fertre <yannick.fertre@st.com> for STMicroelectronics.
+ *
+ */
+
+#ifndef _DSI_HOST_H
+#define _DSI_HOST_H
+
+#include <mipi_dsi.h>
+
+struct dsi_host_ops {
+	/**
+	 * init() - initialized the dsi_host
+	 *
+	 * @dev: dsi host device
+	 * @device: DSI peripheral device
+	 * @timing: Display timings
+	 * @max_data_lanes: maximum number of data lines
+	 * @phy_ops: set of function pointers for performing physical operations
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*init)(struct udevice *dev,
+		    struct mipi_dsi_device *device,
+		    struct display_timing *timings,
+		    unsigned int max_data_lanes,
+		    const struct mipi_dsi_phy_ops *phy_ops);
+
+	/**
+	 * enable() - Enable the dsi_host
+	 *
+	 * @dev: dsi host device
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*enable)(struct udevice *dev);
+
+	/**
+	 * disable() - Disable the dsi_host
+	 *
+	 * @dev: dsi host device
+	 * @return 0 if OK, -ve on error
+	 */
+	int (*disable)(struct udevice *dev);
+};
+
+#define dsi_host_get_ops(dev)	((struct dsi_host_ops *)(dev)->driver->ops)
+
+/**
+ * dsi_host_init
+ *
+ * @dev: dsi host device
+ * @device: DSI peripheral device
+ * @timing: Display timings
+ * @max_data_lanes: maximum number of data lines
+ * @phy_ops: set of function pointers for performing physical operations
+ * @return 0 if OK, -ve on error
+ */
+int dsi_host_init(struct udevice *dev,
+		  struct mipi_dsi_device *device,
+		  struct display_timing *timings,
+		  unsigned int max_data_lanes,
+		  const struct mipi_dsi_phy_ops *phy_ops);
+
+/**
+ * dsi_host_enable
+ *
+ * @dev:	dsi host device
+ * @return 0 if OK, -ve on error
+ */
+int dsi_host_enable(struct udevice *dev);
+
+#endif

test/dm/Makefile

@@ -18,6 +18,7 @@ obj-$(CONFIG_BLK) += blk.o
 obj-$(CONFIG_BOARD) += board.o
 obj-$(CONFIG_DM_BOOTCOUNT) += bootcount.o
 obj-$(CONFIG_CLK) += clk.o clk_ccf.o
+obj-$(CONFIG_VIDEO_MIPI_DSI) += dsi_host.o
 obj-$(CONFIG_DM_ETH) += eth.o
 obj-$(CONFIG_FIRMWARE) += firmware.o
 obj-$(CONFIG_DM_GPIO) += gpio.o

test/dm/dsi_host.c

@@ -0,0 +1,58 @@
+// SPDX-License-Identifier: GPL-2.0+ OR BSD-3-Clause
+/*
+ * Copyright (C) 2019 STMicroelectronics - All Rights Reserved
+ * Author(s): Yannick Fertre <yannick.fertre@st.com> for STMicroelectronics.
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dsi_host.h>
+#include <asm/state.h>
+#include <asm/test.h>
+#include <dm/test.h>
+#include <test/ut.h>
+
+static int dm_test_dsi_host_phy_init(void *priv_data)
+{
+	return 0;
+}
+
+static void dm_test_dsi_host_phy_post_set_mode(void *priv_data,
+					       unsigned long mode_flags)
+{
+}
+
+static int dm_test_dsi_host_phy_get_lane_mbps(void *priv_data,
+					      struct display_timing *timings,
+					      u32 lanes,
+					      u32 format,
+					      unsigned int *lane_mbps)
+{
+	return 0;
+}
+
+static const struct mipi_dsi_phy_ops dm_test_dsi_host_phy_ops = {
+	.init = dm_test_dsi_host_phy_init,
+	.get_lane_mbps = dm_test_dsi_host_phy_get_lane_mbps,
+	.post_set_mode = dm_test_dsi_host_phy_post_set_mode,
+};
+
+/* Test that dsi_host driver functions are called */
+static int dm_test_dsi_host(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+	struct mipi_dsi_device device;
+	struct display_timing timings;
+	unsigned int max_data_lanes = 4;
+
+	ut_assertok(uclass_first_device_err(UCLASS_DSI_HOST, &dev));
+
+	ut_assertok(dsi_host_init(dev, &device, &timings, max_data_lanes,
+				  &dm_test_dsi_host_phy_ops));
+
+	ut_assertok(dsi_host_enable(dev));
+
+	return 0;
+}
+
+DM_TEST(dm_test_dsi_host, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);