Port the panel-mipi-dbi driver from the Linux kernel. It works with most
MIPI DBI compatible SPI panels.
This avoids adding a driver for every new MIPI DBI compatible controller
that is to be used by Barebox. The 'compatible' Device Tree property
with a '.bin' suffix will be used to load a firmware file that contains
the controller configuration.
Example (driver will load sainsmart18.bin):
display@0 {
compatible = "sainsmart18", "panel-mipi-dbi-spi";
...
};
Signed-off-by: Philipp Zabel <p.za...@pengutronix.de>
---
drivers/video/Kconfig | 12 ++
drivers/video/Makefile | 1 +
drivers/video/panel-mipi-dbi.c | 330 +++++++++++++++++++++++++++++++++
3 files changed, 343 insertions(+)
create mode 100644 drivers/video/panel-mipi-dbi.c
diff --git a/drivers/video/Kconfig b/drivers/video/Kconfig
index 01bdaf47bfca..0e710bb25f79 100644
--- a/drivers/video/Kconfig
+++ b/drivers/video/Kconfig
@@ -198,4 +198,16 @@ config DRIVER_VIDEO_PANEL_ILITEK_ILI9341
QVGA (240x320) RGB panels. support serial & parallel rgb
interface.
+config DRIVER_VIDEO_PANEL_MIPI_DBI
+ tristate "DRM support for MIPI DBI compatible panels"
+ depends on OFTREE && SPI
+ select DRIVER_VIDEO_MIPI_DBI
+ select FIRMWARE
+ select VIDEO_VPL
+ help
+ Say Y here if you want to enable support for MIPI DBI compatible
+ panels. The controller command setup can be provided using a
+ firmware file. For more information see
+ https://github.com/notro/panel-mipi-dbi/wiki.
+
endif
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index d50d2d3ba562..7718b63f448a 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_DRIVER_VIDEO_TC358767) += tc358767.o
obj-$(CONFIG_DRIVER_VIDEO_SIMPLE_PANEL) += simple-panel.o
obj-$(CONFIG_DRIVER_VIDEO_MIPI_DBI) += mipi_dbi.o
obj-$(CONFIG_DRIVER_VIDEO_PANEL_ILITEK_ILI9341) += panel-ilitek-ili9341.o
+obj-$(CONFIG_DRIVER_VIDEO_PANEL_MIPI_DBI) += panel-mipi-dbi.o
obj-$(CONFIG_DRIVER_VIDEO_ATMEL) += atmel_lcdfb.o atmel_lcdfb_core.o
obj-$(CONFIG_DRIVER_VIDEO_ATMEL_HLCD) += atmel_hlcdfb.o atmel_lcdfb_core.o
diff --git a/drivers/video/panel-mipi-dbi.c b/drivers/video/panel-mipi-dbi.c
new file mode 100644
index 000000000000..ac6f585be32c
--- /dev/null
+++ b/drivers/video/panel-mipi-dbi.c
@@ -0,0 +1,330 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * DRM driver for MIPI DBI compatible display panels
+ *
+ * Copyright 2022 Noralf Trønnes
+ */
+
+#include <clock.h>
+#include <common.h>
+#include <fb.h>
+#include <firmware.h>
+#include <gpiod.h>
+#include <linux/printk.h>
+#include <of.h>
+#include <regulator.h>
+#include <spi/spi.h>
+
+#include <video/backlight.h>
+#include <video/mipi_dbi.h>
+#include <video/mipi_display.h>
+
+static const u8 panel_mipi_dbi_magic[15] = { 'M', 'I', 'P', 'I', ' ', 'D',
'B', 'I',
+ 0, 0, 0, 0, 0, 0, 0 };
+
+/*
+ * The display controller configuration is stored in a firmware file.
+ * The Device Tree 'compatible' property value with a '.bin' suffix is passed
+ * to request_firmware() to fetch this file.
+ */
+struct panel_mipi_dbi_config {
+ /* Magic string: panel_mipi_dbi_magic */
+ u8 magic[15];
+
+ /* Config file format version */
+ u8 file_format_version;
+
+ /*
+ * MIPI commands to execute when the display pipeline is enabled.
+ * This is used to configure the display controller.
+ *
+ * The commands are stored in a byte array with the format:
+ * command, num_parameters, [ parameter, ...], command, ...
+ *
+ * Some commands require a pause before the next command can be
received.
+ * Inserting a delay in the command sequence is done by using the NOP
command with one
+ * parameter: delay in miliseconds (the No Operation command is part of
the MIPI Display
+ * Command Set where it has no parameters).
+ *
+ * Example:
+ * command 0x11
+ * sleep 120ms
+ * command 0xb1 parameters 0x01, 0x2c, 0x2d
+ * command 0x29
+ *
+ * Byte sequence:
+ * 0x11 0x00
+ * 0x00 0x01 0x78
+ * 0xb1 0x03 0x01 0x2c 0x2d
+ * 0x29 0x00
+ */
+ u8 commands[];
+};
+
+struct panel_mipi_dbi_commands {
+ const u8 *buf;
+ size_t len;
+};
+
+static struct panel_mipi_dbi_commands *
+panel_mipi_dbi_check_commands(struct device *dev, const struct firmware *fw)
+{
+ const struct panel_mipi_dbi_config *config = (struct
panel_mipi_dbi_config *)fw->data;
+ struct panel_mipi_dbi_commands *commands;
+ size_t size = fw->size, commands_len;
+ unsigned int i = 0;
+
+ if (size < sizeof(*config) + 2) { /* At least 1 command */
+ dev_err(dev, "config: file size=%zu is too small\n", size);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (memcmp(config->magic, panel_mipi_dbi_magic, sizeof(config->magic)))
{
+ dev_err(dev, "config: Bad magic: %15ph\n", config->magic);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (config->file_format_version != 1) {
+ dev_err(dev, "config: version=%u is not supported\n",
config->file_format_version);
+ return ERR_PTR(-EINVAL);
+ }
+
+ dev_dbg(dev, "size=%zu version=%u\n", size,
config->file_format_version);
+
+ commands_len = size - sizeof(*config);
+
+ while ((i + 1) < commands_len) {
+ u8 command = config->commands[i++];
+ u8 num_parameters = config->commands[i++];
+ const u8 *parameters = &config->commands[i];
+
+ i += num_parameters;
+ if (i > commands_len) {
+ dev_err(dev, "config: command=0x%02x num_parameters=%u
overflows\n",
+ command, num_parameters);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (command == 0x00 && num_parameters == 1)
+ dev_dbg(dev, "sleep %ums\n", parameters[0]);
+ else
+ dev_dbg(dev, "command %02x %*ph\n",
+ command, num_parameters, parameters);
+ }
+
+ if (i != commands_len) {
+ dev_err(dev, "config: malformed command array\n");
+ return ERR_PTR(-EINVAL);
+ }
+
+ commands = kzalloc(sizeof(*commands), GFP_KERNEL);
+ if (!commands)
+ return ERR_PTR(-ENOMEM);
+
+ commands->len = commands_len;
+ commands->buf = kmemdup(config->commands, commands->len, GFP_KERNEL);
+ if (!commands->buf)
+ return ERR_PTR(-ENOMEM);
+
+ return commands;
+}
+
+static struct panel_mipi_dbi_commands *panel_mipi_dbi_commands_from_fw(struct
device *dev)
+{
+ struct panel_mipi_dbi_commands *commands;
+ const struct firmware *fw;
+ const char *compatible;
+ char fw_name[40];
+ int ret;
+
+ ret = of_property_read_string_index(dev->of_node, "compatible", 0,
&compatible);
+ if (ret)
+ return ERR_PTR(ret);
+
+ snprintf(fw_name, sizeof(fw_name), "%s.bin", compatible);
+ ret = request_firmware(&fw, fw_name, dev);
+ if (ret) {
+ dev_err(dev, "No config file found for compatible '%s'
(error=%d)\n",
+ compatible, ret);
+
+ return ERR_PTR(ret);
+ }
+
+ commands = panel_mipi_dbi_check_commands(dev, fw);
+ release_firmware(fw);
+
+ return commands;
+}
+
+static void panel_mipi_dbi_commands_execute(struct mipi_dbi *dbi,
+ struct panel_mipi_dbi_commands
*commands)
+{
+ unsigned int i = 0;
+
+ if (!commands)
+ return;
+
+ while (i < commands->len) {
+ u8 command = commands->buf[i++];
+ u8 num_parameters = commands->buf[i++];
+ const u8 *parameters = &commands->buf[i];
+
+ if (command == 0x00 && num_parameters == 1)
+ mdelay(parameters[0]);
+ else if (num_parameters)
+ mipi_dbi_command_stackbuf(dbi, command, parameters,
num_parameters);
+ else
+ mipi_dbi_command(dbi, command);
+
+ i += num_parameters;
+ }
+}
+
+static void panel_mipi_dbi_enable(struct fb_info *info)
+{
+ struct mipi_dbi_dev *dbidev = container_of(info, struct mipi_dbi_dev,
info);
+ struct mipi_dbi *dbi = &dbidev->dbi;
+ int ret;
+
+ if (!info->mode) {
+ dev_err(dbidev->dev, "No valid mode found\n");
+ return;
+ }
+
+ if (dbidev->backlight_node && !dbidev->backlight) {
+ dbidev->backlight = of_backlight_find(dbidev->backlight_node);
+ if (!dbidev->backlight)
+ dev_err(dbidev->dev, "No backlight found\n");
+ }
+
+ if (!dbidev->driver_private) {
+ dbidev->driver_private =
panel_mipi_dbi_commands_from_fw(dbidev->dev);
+ if (IS_ERR(dbidev->driver_private)) {
+ dbidev->driver_private = NULL;
+ return;
+ }
+ }
+
+ ret = mipi_dbi_poweron_conditional_reset(dbidev);
+ if (ret < 0)
+ return;
+ if (!ret)
+ panel_mipi_dbi_commands_execute(dbi, dbidev->driver_private);
+
+ mipi_dbi_enable_flush(dbidev, info);
+}
+
+
+static struct fb_ops panel_mipi_dbi_ops = {
+ .fb_enable = panel_mipi_dbi_enable,
+ .fb_disable = mipi_dbi_fb_disable,
+ .fb_flush = mipi_dbi_fb_flush,
+};
+
+
+static int panel_mipi_dbi_get_mode(struct mipi_dbi_dev *dbidev, struct
fb_videomode *mode)
+{
+ struct device *dev = dbidev->dev;
+ int ret;
+
+ ret = of_get_display_timing(dev->of_node, "panel-timing", mode);
+ if (ret) {
+ dev_err(dev, "%pOF: failed to get panel-timing (error=%d)\n",
dev->of_node, ret);
+ return ret;
+ }
+
+ /*
+ * Make sure width and height are set and that only back porch and
+ * pixelclock are set in the other timing values. Also check that
+ * width and height don't exceed the 16-bit value specified by MIPI DCS.
+ */
+ if (!mode->xres || !mode->yres || mode->display_flags ||
+ mode->right_margin || mode->hsync_len || (mode->left_margin +
mode->xres) > 0xffff ||
+ mode->lower_margin || mode->vsync_len || (mode->upper_margin +
mode->yres) > 0xffff) {
+ dev_err(dev, "%pOF: panel-timing out of bounds\n",
dev->of_node);
+ return -EINVAL;
+ }
+
+ /* The driver doesn't use the pixel clock but it is mandatory so fake
one if not set */
+ if (!mode->pixclock) {
+ mode->pixclock =
+ (mode->left_margin + mode->xres + mode->right_margin +
mode->hsync_len) *
+ (mode->upper_margin + mode->yres + mode->lower_margin +
mode->vsync_len) *
+ 60 / 1000;
+ }
+
+ return 0;
+}
+
+static int panel_mipi_dbi_spi_probe(struct device *dev)
+{
+ struct mipi_dbi_dev *dbidev;
+ struct spi_device *spi = to_spi_device(dev);
+ struct mipi_dbi *dbi;
+ struct fb_info *info;
+ int dc;
+ int ret;
+
+ dbidev = kzalloc(sizeof(*dbidev), GFP_KERNEL);
+ if (!dbidev)
+ return -ENOMEM;
+
+ dbidev->dev = dev;
+ dbi = &dbidev->dbi;
+ info = &dbidev->info;
+
+ ret = panel_mipi_dbi_get_mode(dbidev, &dbidev->mode);
+ if (ret)
+ return ret;
+
+ dbidev->regulator = regulator_get(dev, "power");
+ if (IS_ERR(dbidev->regulator))
+ return dev_err_probe(dev, PTR_ERR(dbidev->regulator),
+ "Failed to get regulator 'power'\n");
+
+ dbidev->io_regulator = regulator_get(dev, "io");
+ if (IS_ERR(dbidev->io_regulator))
+ return dev_err_probe(dev, PTR_ERR(dbidev->io_regulator),
+ "Failed to get regulator 'io'\n");
+
+ dbidev->backlight_node = of_parse_phandle(dev->of_node, "backlight", 0);
+
+ dbi->reset = gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+ if (dbi->reset < 0 && dbi->reset != -ENOENT)
+ return dev_err_probe(dev, dbi->reset, "Failed to get GPIO
'reset'\n");
+
+ dc = gpiod_get(dev, "dc", GPIOD_OUT_LOW);
+ if (dc < 0 && dc != -ENOENT)
+ return dev_err_probe(dev, dc, "Failed to get GPIO 'dc'\n");
+
+ ret = mipi_dbi_spi_init(spi, dbi, dc);
+ if (ret)
+ return ret;
+
+ ret = mipi_dbi_dev_init(dbidev, &panel_mipi_dbi_ops, &dbidev->mode);
+ if (ret)
+ return ret;
+
+ ret = register_framebuffer(info);
+ if (ret < 0)
+ return dev_err_probe(dev, ret, "Failed to register
framebuffer\n");
+
+ return 0;
+}
+
+static const struct of_device_id panel_mipi_dbi_spi_of_match[] = {
+ { .compatible = "panel-mipi-dbi-spi" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, panel_mipi_dbi_spi_of_match);
+
+static struct driver panel_mipi_dbi_spi_driver = {
+ .name = "panel-mipi-dbi-spi",
+ .probe = panel_mipi_dbi_spi_probe,
+ .of_compatible = DRV_OF_COMPAT(panel_mipi_dbi_spi_of_match),
+};
+device_spi_driver(panel_mipi_dbi_spi_driver);
+
+MODULE_DESCRIPTION("MIPI DBI compatible display panel driver");
+MODULE_AUTHOR("Noralf Trønnes");
+MODULE_LICENSE("GPL");
--
2.39.2
