video: tegra: add 8-bit CPU driven protocol
Add support for 8-bit CPU driven (primary and secondary) display signal
interface found in Tegra 2 and Tegra 3 SoC.
Tested-by: Ion Agorria <ion@agorria.com>
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>
diff --git a/drivers/video/tegra/cpu-bridge.c b/drivers/video/tegra/cpu-bridge.c
new file mode 100644
index 0000000..e5fefe0
--- /dev/null
+++ b/drivers/video/tegra/cpu-bridge.c
@@ -0,0 +1,325 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2024 Svyatoslav Ryhel <clamor95@gmail.com>
+ *
+ * This driver uses 8-bit CPU interface found in Tegra 2
+ * and Tegra 3 to drive MIPI DSI panel.
+ */
+
+#include <dm.h>
+#include <dm/ofnode_graph.h>
+#include <log.h>
+#include <mipi_display.h>
+#include <mipi_dsi.h>
+#include <backlight.h>
+#include <panel.h>
+#include <video_bridge.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <asm/gpio.h>
+#include <asm/io.h>
+
+#include "dc.h"
+
+struct tegra_cpu_bridge_priv {
+ struct dc_ctlr *dc;
+
+ struct mipi_dsi_host host;
+ struct mipi_dsi_device device;
+
+ struct udevice *panel;
+ struct display_timing timing;
+
+ struct gpio_desc dc_gpio;
+ struct gpio_desc rw_gpio;
+ struct gpio_desc cs_gpio;
+
+ struct gpio_desc data_gpios[8];
+
+ u32 pixel_format;
+ u32 spi_init_seq[4];
+};
+
+#define TEGRA_CPU_BRIDGE_COMM 0
+#define TEGRA_CPU_BRIDGE_DATA 1
+
+static void tegra_cpu_bridge_write(struct tegra_cpu_bridge_priv *priv,
+ u8 type, u8 value)
+{
+ int i;
+
+ dm_gpio_set_value(&priv->dc_gpio, type);
+
+ dm_gpio_set_value(&priv->cs_gpio, 0);
+ dm_gpio_set_value(&priv->rw_gpio, 0);
+
+ for (i = 0; i < 8; i++)
+ dm_gpio_set_value(&priv->data_gpios[i],
+ (value >> i) & 0x1);
+
+ dm_gpio_set_value(&priv->cs_gpio, 1);
+ dm_gpio_set_value(&priv->rw_gpio, 1);
+
+ udelay(10);
+
+ log_debug("%s: type 0x%x, val 0x%x\n",
+ __func__, type, value);
+}
+
+static ssize_t tegra_cpu_bridge_transfer(struct mipi_dsi_host *host,
+ const struct mipi_dsi_msg *msg)
+{
+ struct udevice *dev = (struct udevice *)host->dev;
+ struct tegra_cpu_bridge_priv *priv = dev_get_priv(dev);
+ u8 command = *(u8 *)msg->tx_buf;
+ const u8 *data = msg->tx_buf;
+ int i;
+
+ tegra_cpu_bridge_write(priv, TEGRA_CPU_BRIDGE_COMM, command);
+
+ for (i = 1; i < msg->tx_len; i++)
+ tegra_cpu_bridge_write(priv, TEGRA_CPU_BRIDGE_DATA, data[i]);
+
+ return 0;
+}
+
+static const struct mipi_dsi_host_ops tegra_cpu_bridge_host_ops = {
+ .transfer = tegra_cpu_bridge_transfer,
+};
+
+static int tegra_cpu_bridge_get_format(enum mipi_dsi_pixel_format format, u32 *fmt)
+{
+ switch (format) {
+ case MIPI_DSI_FMT_RGB888:
+ case MIPI_DSI_FMT_RGB666_PACKED:
+ *fmt = BASE_COLOR_SIZE_888;
+ break;
+
+ case MIPI_DSI_FMT_RGB666:
+ *fmt = BASE_COLOR_SIZE_666;
+ break;
+
+ case MIPI_DSI_FMT_RGB565:
+ *fmt = BASE_COLOR_SIZE_565;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int tegra_cpu_bridge_attach(struct udevice *dev)
+{
+ struct tegra_cpu_bridge_priv *priv = dev_get_priv(dev);
+ struct dc_disp_reg *disp = &priv->dc->disp;
+ struct dc_cmd_reg *cmd = &priv->dc->cmd;
+ struct dc_com_reg *com = &priv->dc->com;
+ u32 value;
+ int ret;
+
+ writel(CTRL_MODE_STOP << CTRL_MODE_SHIFT, &cmd->disp_cmd);
+ writel(0, &disp->disp_win_opt);
+ writel(GENERAL_UPDATE, &cmd->state_ctrl);
+ writel(GENERAL_ACT_REQ, &cmd->state_ctrl);
+
+ /* TODO: parametrize if needed */
+ writel(V_PULSE1_ENABLE, &disp->disp_signal_opt0);
+ writel(PULSE_POLARITY_LOW, &disp->v_pulse1.v_pulse_ctrl);
+
+ writel(PULSE_END(1), &disp->v_pulse1.v_pulse_pos[V_PULSE0_POSITION_A]);
+ writel(0, &disp->v_pulse1.v_pulse_pos[V_PULSE0_POSITION_B]);
+ writel(0, &disp->v_pulse1.v_pulse_pos[V_PULSE0_POSITION_C]);
+
+ ret = dev_read_u32_array(dev, "nvidia,init-sequence", priv->spi_init_seq, 4);
+ if (!ret) {
+ value = 1 << FRAME_INIT_SEQ_CYCLES_SHIFT |
+ DC_SIGNAL_VPULSE1 << INIT_SEQ_DC_SIGNAL_SHIFT |
+ INIT_SEQUENCE_MODE_PLCD | SEND_INIT_SEQUENCE;
+ writel(value, &disp->seq_ctrl);
+
+ writel(priv->spi_init_seq[0], &disp->spi_init_seq_data_a);
+ writel(priv->spi_init_seq[1], &disp->spi_init_seq_data_b);
+ writel(priv->spi_init_seq[2], &disp->spi_init_seq_data_c);
+ writel(priv->spi_init_seq[3], &disp->spi_init_seq_data_d);
+ }
+
+ value = readl(&cmd->disp_cmd);
+ value &= ~CTRL_MODE_MASK;
+ value |= CTRL_MODE_C_DISPLAY << CTRL_MODE_SHIFT;
+ writel(value, &cmd->disp_cmd);
+
+ /* set LDC pin to V Pulse 1 */
+ value = readl(&com->pin_output_sel[6]) | LDC_OUTPUT_SELECT_V_PULSE1;
+ writel(value, &com->pin_output_sel[6]);
+
+ value = readl(&disp->disp_interface_ctrl);
+ value |= DATA_ALIGNMENT_LSB << DATA_ALIGNMENT_SHIFT;
+ writel(value, &disp->disp_interface_ctrl);
+
+ value = SC_H_QUALIFIER_NONE << SC1_H_QUALIFIER_SHIFT |
+ SC_V_QUALIFIER_VACTIVE << SC0_V_QUALIFIER_SHIFT |
+ SC_H_QUALIFIER_HACTIVE << SC0_H_QUALIFIER_SHIFT;
+ writel(value, &disp->shift_clk_opt);
+
+ value = readl(&disp->disp_color_ctrl);
+ value |= priv->pixel_format;
+ writel(value, &disp->disp_color_ctrl);
+
+ /* Perform panel setup */
+ panel_enable_backlight(priv->panel);
+
+ dm_gpio_set_value(&priv->cs_gpio, 0);
+
+ dm_gpio_free(dev, &priv->dc_gpio);
+ dm_gpio_free(dev, &priv->rw_gpio);
+ dm_gpio_free(dev, &priv->cs_gpio);
+
+ gpio_free_list(dev, priv->data_gpios, 8);
+
+ return 0;
+}
+
+static int tegra_cpu_bridge_set_panel(struct udevice *dev, int percent)
+{
+ struct tegra_cpu_bridge_priv *priv = dev_get_priv(dev);
+
+ return panel_set_backlight(priv->panel, percent);
+}
+
+static int tegra_cpu_bridge_panel_timings(struct udevice *dev,
+ struct display_timing *timing)
+{
+ struct tegra_cpu_bridge_priv *priv = dev_get_priv(dev);
+
+ memcpy(timing, &priv->timing, sizeof(*timing));
+
+ return 0;
+}
+
+static int tegra_cpu_bridge_hw_init(struct udevice *dev)
+{
+ struct tegra_cpu_bridge_priv *priv = dev_get_priv(dev);
+
+ dm_gpio_set_value(&priv->cs_gpio, 1);
+
+ dm_gpio_set_value(&priv->rw_gpio, 1);
+ dm_gpio_set_value(&priv->dc_gpio, 0);
+
+ return 0;
+}
+
+static int tegra_cpu_bridge_get_links(struct udevice *dev)
+{
+ struct tegra_cpu_bridge_priv *priv = dev_get_priv(dev);
+ int i, ret;
+
+ u32 num = ofnode_graph_get_port_count(dev_ofnode(dev));
+
+ for (i = 0; i < num; i++) {
+ ofnode remote = ofnode_graph_get_remote_node(dev_ofnode(dev), i, -1);
+
+ /* Look for DC source */
+ if (ofnode_name_eq(remote, "rgb")) {
+ ofnode dc = ofnode_get_parent(remote);
+
+ priv->dc = (struct dc_ctlr *)ofnode_get_addr(dc);
+ if (!priv->dc) {
+ log_err("%s: failed to get DC controller\n", __func__);
+ return -EINVAL;
+ }
+ }
+
+ /* Look for driven panel */
+ ret = uclass_get_device_by_ofnode(UCLASS_PANEL, remote, &priv->panel);
+ if (!ret)
+ return 0;
+ }
+
+ /* If this point is reached, no panels were found */
+ return -ENODEV;
+}
+
+static int tegra_cpu_bridge_probe(struct udevice *dev)
+{
+ struct tegra_cpu_bridge_priv *priv = dev_get_priv(dev);
+ struct mipi_dsi_device *device = &priv->device;
+ struct mipi_dsi_panel_plat *mipi_plat;
+ int ret;
+
+ ret = tegra_cpu_bridge_get_links(dev);
+ if (ret) {
+ log_debug("%s: links not found, ret %d\n", __func__, ret);
+ return ret;
+ }
+
+ panel_get_display_timing(priv->panel, &priv->timing);
+
+ mipi_plat = dev_get_plat(priv->panel);
+ mipi_plat->device = device;
+
+ priv->host.dev = (struct device *)dev;
+ priv->host.ops = &tegra_cpu_bridge_host_ops;
+
+ device->host = &priv->host;
+ device->lanes = mipi_plat->lanes;
+ device->format = mipi_plat->format;
+ device->mode_flags = mipi_plat->mode_flags;
+
+ tegra_cpu_bridge_get_format(device->format, &priv->pixel_format);
+
+ /* get control gpios */
+ ret = gpio_request_by_name(dev, "dc-gpios", 0,
+ &priv->dc_gpio, GPIOD_IS_OUT);
+ if (ret) {
+ log_debug("%s: could not decode dc-gpios (%d)\n", __func__, ret);
+ return ret;
+ }
+
+ ret = gpio_request_by_name(dev, "rw-gpios", 0,
+ &priv->rw_gpio, GPIOD_IS_OUT);
+ if (ret) {
+ log_debug("%s: could not decode rw-gpios (%d)\n", __func__, ret);
+ return ret;
+ }
+
+ ret = gpio_request_by_name(dev, "cs-gpios", 0,
+ &priv->cs_gpio, GPIOD_IS_OUT);
+ if (ret) {
+ log_debug("%s: could not decode cs-gpios (%d)\n", __func__, ret);
+ return ret;
+ }
+
+ /* get data gpios */
+ ret = gpio_request_list_by_name(dev, "data-gpios",
+ priv->data_gpios, 8,
+ GPIOD_IS_OUT);
+ if (ret < 0) {
+ log_debug("%s: could not decode data-gpios (%d)\n", __func__, ret);
+ return ret;
+ }
+
+ return tegra_cpu_bridge_hw_init(dev);
+}
+
+static const struct video_bridge_ops tegra_cpu_bridge_ops = {
+ .attach = tegra_cpu_bridge_attach,
+ .set_backlight = tegra_cpu_bridge_set_panel,
+ .get_display_timing = tegra_cpu_bridge_panel_timings,
+};
+
+static const struct udevice_id tegra_cpu_bridge_ids[] = {
+ { .compatible = "nvidia,tegra-8bit-cpu" },
+ { }
+};
+
+U_BOOT_DRIVER(tegra_8bit_cpu) = {
+ .name = "tegra_8bit_cpu",
+ .id = UCLASS_VIDEO_BRIDGE,
+ .of_match = tegra_cpu_bridge_ids,
+ .ops = &tegra_cpu_bridge_ops,
+ .bind = dm_scan_fdt_dev,
+ .probe = tegra_cpu_bridge_probe,
+ .priv_auto = sizeof(struct tegra_cpu_bridge_priv),
+};