@@ -7116,6 +7116,12 @@ S: Maintained
F: Documentation/devicetree/bindings/display/panel/samsung,s6d7aa0.yaml
F: drivers/gpu/drm/panel/panel-samsung-s6d7aa0.c
+DRM DRIVER FOR SITRONIX ST7539 PANELS
+M: Christian Eggers <ceggers@arri.de>
+S: Maintained
+T: git https://gitlab.freedesktop.org/drm/misc/kernel.git
+F: drivers/gpu/drm/tiny/st7539.c
+
DRM DRIVER FOR SITRONIX ST7586 PANELS
M: David Lechner <david@lechnology.com>
S: Maintained
@@ -186,6 +186,17 @@ config TINYDRM_REPAPER
If M is selected the module will be called repaper.
+config TINYDRM_ST7539
+ tristate "DRM support for Sitronix ST7539 display panels"
+ depends on DRM && SPI
+ select DRM_KMS_HELPER
+ select DRM_GEM_DMA_HELPER
+ select DRM_MIPI_DBI
+ help
+ DRM driver for Sitronix ST7539 panels.
+
+ If M is selected the module will be called st7539.
+
config TINYDRM_ST7586
tristate "DRM support for Sitronix ST7586 display panels"
depends on DRM && SPI
@@ -14,5 +14,6 @@ obj-$(CONFIG_TINYDRM_ILI9341) += ili9341.o
obj-$(CONFIG_TINYDRM_ILI9486) += ili9486.o
obj-$(CONFIG_TINYDRM_MI0283QT) += mi0283qt.o
obj-$(CONFIG_TINYDRM_REPAPER) += repaper.o
+obj-$(CONFIG_TINYDRM_ST7539) += st7539.o
obj-$(CONFIG_TINYDRM_ST7586) += st7586.o
obj-$(CONFIG_TINYDRM_ST7735R) += st7735r.o
new file mode 100644
@@ -0,0 +1,424 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * DRM driver for Sitronix ST7539 panels
+ *
+ * Copyright 2024 Christian Eggers <ceggers@arri.de>
+ *
+ * based on st7586.c
+ * Copyright 2017 David Lechner <david@lechnology.com>
+ */
+
+#include <linux/delay.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/spi/spi.h>
+#include <video/mipi_display.h>
+
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_damage_helper.h>
+#include <drm/drm_drv.h>
+#include <drm/drm_fb_dma_helper.h>
+#include <drm/drm_fbdev_dma.h>
+#include <drm/drm_format_helper.h>
+#include <drm/drm_framebuffer.h>
+#include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_gem_dma_helper.h>
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/drm_managed.h>
+#include <drm/drm_mipi_dbi.h>
+#include <drm/drm_rect.h>
+
+/* controller-specific commands */
+#define ST7539_SET_COLUMN_ADDRESS_LSB(CA) (0x00 | ((CA) & 0x0f))
+#define ST7539_SET_COLUMN_ADDRESS_MSB(CA) (0x10 | (((CA) & 0xff) >> 4))
+#define ST7539_SET_SCROLL_LINE(x) (0x40 | ((x) & 0x3f))
+#define ST7539_SET_CONTRAST 0x81 /* + 1 byte value */
+#define ST7539_SET_FPS__76 0xA0 /* 76 fps */
+#define ST7539_SET_FPS__95 0xA1 /* 95 fps */
+#define ST7539_SET_FPS__132 0xA2 /* 132 fps */
+#define ST7539_SET_FPS__168 0xA3 /* 168 fps */
+#define ST7539_SET_DISP_NORMAL 0xA6 /* non inverse */
+#define ST7539_SET_DISP_INVERSE 0xA7 /* inverse display */
+#define ST7539_SET_DISP_OFF 0xAE /* display off and controller power down */
+#define ST7539_SET_DISP_ON 0xAF /* display on and controller power on */
+#define ST7539_SET_PAGE_ADDRESS(PA) (0xB0 | ((PA) & 0xf))
+#define ST7539_SET_SCAN_NORMAL 0xC0 /* MX=0, MY=0 */
+#define ST7539_SET_SCAN_X_INV 0xC2 /* MX=1, MY=0 */
+#define ST7539_SET_SCAN_Y_INV 0xC4 /* MX=0, MY=1 */
+#define ST7539_SET_SCAN_XY_INV 0xC6 /* MX=1, MY=1 */
+#define ST7539_SOFT_RESET 0xE2
+#define ST7539_NOP 0xE3
+#define ST7539_SET_BIAS__1_6 0xE8 /* 1/6 */
+#define ST7539_SET_BIAS__1_7 0xE9 /* 1/7 */
+#define ST7539_SET_BIAS__1_8 0xEA /* 1/8 */
+#define ST7539_SET_BIAS__1_9 0xEB /* 1/9 */
+
+#define ST7539_HOR_RES 192
+#define ST7539_VER_RES 64
+
+/* slightly modified version of from mipi_dbi_typec3_command() */
+static int st7539_dbi_command_buf(struct mipi_dbi *dbi,
+ u8 *cmd, size_t cmd_len,
+ u8 *par, size_t num)
+{
+ struct spi_device *spi = dbi->spi;
+ u32 speed_hz;
+ int ret = 0;
+
+ spi_bus_lock(spi->controller);
+ gpiod_set_value_cansleep(dbi->dc, 0);
+ speed_hz = mipi_dbi_spi_cmd_max_speed(spi, cmd_len);
+ ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, cmd, cmd_len);
+ spi_bus_unlock(spi->controller);
+ if (ret || !num)
+ return ret;
+
+ spi_bus_lock(spi->controller);
+ gpiod_set_value_cansleep(dbi->dc, 1);
+ speed_hz = mipi_dbi_spi_cmd_max_speed(spi, num);
+ ret = mipi_dbi_spi_transfer(spi, speed_hz, 8, par, num);
+ spi_bus_unlock(spi->controller);
+
+ return ret;
+}
+
+/**
+ * st7539_dbi_command16 - Command with 2 bytes
+ * @dbi: MIPI DBI structure
+ * @cmd: Array of two command bytes
+ *
+ * Returns:
+ * Zero on success, negative error code on failure.
+ */
+static int st7539_dbi_command16(struct mipi_dbi *dbi, const u8 *cmd)
+{
+ u8 *cmdbuf;
+ int ret;
+
+ /* SPI requires dma-safe buffers */
+ cmdbuf = kmemdup(cmd, 2, GFP_KERNEL);
+ if (!cmdbuf)
+ return -ENOMEM;
+
+ mutex_lock(&dbi->cmdlock);
+ ret = st7539_dbi_command_buf(dbi, cmdbuf, 2, NULL, 0);
+ mutex_unlock(&dbi->cmdlock);
+
+ kfree(cmdbuf);
+
+ return ret;
+}
+
+static int st7539_dbi_typec3_command(struct mipi_dbi *dbi,
+ u8 *cmd, u8 *par, size_t num)
+{
+ return st7539_dbi_command_buf(dbi, cmd, 1, par, num);
+}
+
+/*
+ * The ST7539 controller packs 8 VERTICAL pixels into one byte
+ * (similar as "page_address_mode" for SH1106 in drm/solomon/ssd130x.c).
+ */
+
+static void st7539_xrgb8888_to_mono(u8 *dst, struct iosys_map *src,
+ struct drm_framebuffer *fb,
+ struct drm_rect *clip,
+ struct drm_format_conv_state *fmtcnv_state)
+{
+ u8 *buf;
+ struct iosys_map dst_map;
+
+ unsigned int width = drm_rect_width(clip);
+ unsigned int height = drm_rect_height(clip);
+ unsigned int line_length = DIV_ROUND_UP(width, 8);
+ unsigned int page_height = 8;
+ unsigned int pages = DIV_ROUND_UP(height, page_height);
+ size_t len = pages * width;
+ u32 array_idx = 0;
+ int i, j, k;
+
+ /* intermediate buffer (8 horizontal pixels per byte) */
+ buf = kmalloc(len, GFP_KERNEL);
+ if (!buf)
+ return;
+
+ iosys_map_set_vaddr(&dst_map, buf);
+ drm_fb_xrgb8888_to_mono(&dst_map, NULL, src, fb, clip, fmtcnv_state);
+
+ /* convert to 8 VERTICAL pixels per byte */
+ for (i = 0; i < pages; i++) {
+ for (j = 0; j < width; j++) {
+ u8 data = 0;
+
+ for (k = 0; k < 8; k++) {
+ u8 byte = buf[(8 * i + k) * line_length + j / 8];
+ u8 bit = !((byte >> (j % 8)) & 1); /* invert pixels */
+
+ data |= bit << k;
+ }
+ dst[array_idx++] = data;
+ }
+ }
+
+ kfree(buf);
+}
+
+static int st7539_buf_copy(void *dst, struct iosys_map *src, struct drm_framebuffer *fb,
+ struct drm_rect *clip, struct drm_format_conv_state *fmtcnv_state)
+{
+ int ret;
+
+ ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
+ if (ret)
+ return ret;
+
+ st7539_xrgb8888_to_mono(dst, src, fb, clip, fmtcnv_state);
+
+ drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
+
+ return 0;
+}
+
+static void st7539_fb_dirty(struct iosys_map *src, struct drm_framebuffer *fb,
+ struct drm_rect *rect, struct drm_format_conv_state *fmtcnv_state)
+{
+ struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(fb->dev);
+ struct mipi_dbi *dbi = &dbidev->dbi;
+ int start, end, ret = 0;
+
+ /* hardware doesn't support clipping of the column --> send full lines */
+ rect->x1 = 0;
+ rect->x2 = ST7539_HOR_RES;
+ /* 8 pixels per byte, so grow clip to nearest multiple of 8 */
+ rect->y1 = rounddown(rect->y1, 8);
+ rect->y2 = roundup(rect->y2, 8);
+
+ DRM_DEBUG_KMS("Flushing [FB:%d] " DRM_RECT_FMT "\n", fb->base.id, DRM_RECT_ARG(rect));
+
+ ret = st7539_buf_copy(dbidev->tx_buf, src, fb, rect, fmtcnv_state);
+ if (ret)
+ goto err_msg;
+
+ /* Pixels are packed 8 per byte */
+ start = rect->y1 / 8;
+ end = rect->y2 / 8;
+
+ mipi_dbi_command(dbi, ST7539_SET_COLUMN_ADDRESS_LSB(rect->x1 & 0xFF));
+ mipi_dbi_command(dbi, ST7539_SET_COLUMN_ADDRESS_MSB((rect->x1 >> 8) & 0xFF));
+
+ ret = mipi_dbi_command_buf(dbi, ST7539_SET_PAGE_ADDRESS(start),
+ (u8 *)dbidev->tx_buf,
+ (rect->x2 - rect->x1) * (end - start));
+err_msg:
+ if (ret)
+ dev_err_once(fb->dev->dev, "Failed to update display %d\n", ret);
+}
+
+static void st7539_pipe_update(struct drm_simple_display_pipe *pipe,
+ struct drm_plane_state *old_state)
+{
+ struct drm_plane_state *state = pipe->plane.state;
+ struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);
+ struct drm_framebuffer *fb = state->fb;
+ struct drm_rect rect;
+ int idx;
+
+ if (!pipe->crtc.state->active)
+ return;
+
+ if (!drm_dev_enter(fb->dev, &idx))
+ return;
+
+ if (drm_atomic_helper_damage_merged(old_state, state, &rect))
+ st7539_fb_dirty(&shadow_plane_state->data[0], fb, &rect,
+ &shadow_plane_state->fmtcnv_state);
+
+ drm_dev_exit(idx);
+}
+
+static void st7539_pipe_enable(struct drm_simple_display_pipe *pipe,
+ struct drm_crtc_state *crtc_state,
+ struct drm_plane_state *plane_state)
+{
+ struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
+ struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
+ struct drm_framebuffer *fb = plane_state->fb;
+ struct mipi_dbi *dbi = &dbidev->dbi;
+ struct drm_rect rect = {
+ .x1 = 0,
+ .x2 = fb->width,
+ .y1 = 0,
+ .y2 = fb->height,
+ };
+ int idx;
+
+ if (!drm_dev_enter(pipe->crtc.dev, &idx))
+ return;
+
+ DRM_DEBUG_KMS("\n");
+
+ /* Cannot use mipi_dbi_poweron_reset() here as the ST7539 has a non DCI
+ * opcode for soft reset
+ */
+ mipi_dbi_hw_reset(dbi);
+
+ mipi_dbi_command(dbi, ST7539_SOFT_RESET);
+ mipi_dbi_command(dbi, ST7539_SET_FPS__76);
+ mipi_dbi_command(dbi, ST7539_SET_BIAS__1_9);
+ st7539_dbi_command16(dbi, (u8[]){ST7539_SET_CONTRAST, 120});
+ mipi_dbi_command(dbi, ST7539_SET_SCAN_Y_INV); /* ToDo: make this configurable */
+
+ st7539_fb_dirty(&shadow_plane_state->data[0], fb, &rect,
+ &shadow_plane_state->fmtcnv_state);
+
+ mipi_dbi_command(dbi, ST7539_SET_DISP_ON);
+}
+
+static void st7539_pipe_disable(struct drm_simple_display_pipe *pipe)
+{
+ struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev);
+
+ /*
+ * This callback is not protected by drm_dev_enter/exit since we want to
+ * turn off the display on regular driver unload. It's highly unlikely
+ * that the underlying SPI controller is gone should this be called after
+ * unplug.
+ */
+
+ DRM_DEBUG_KMS("\n");
+
+ mipi_dbi_command(&dbidev->dbi, MIPI_DCS_SET_DISPLAY_OFF);
+}
+
+static const u32 st7539_formats[] = {
+ DRM_FORMAT_XRGB8888,
+};
+
+static const struct drm_simple_display_pipe_funcs st7539_pipe_funcs = {
+ .mode_valid = mipi_dbi_pipe_mode_valid,
+ .enable = st7539_pipe_enable,
+ .disable = st7539_pipe_disable,
+ .update = st7539_pipe_update,
+ .begin_fb_access = mipi_dbi_pipe_begin_fb_access,
+ .end_fb_access = mipi_dbi_pipe_end_fb_access,
+ .reset_plane = mipi_dbi_pipe_reset_plane,
+ .duplicate_plane_state = mipi_dbi_pipe_duplicate_plane_state,
+ .destroy_plane_state = mipi_dbi_pipe_destroy_plane_state,
+};
+
+static const struct drm_display_mode st7539_mode = {
+ DRM_SIMPLE_MODE(ST7539_HOR_RES, ST7539_VER_RES, 57, 23),
+};
+
+DEFINE_DRM_GEM_DMA_FOPS(st7539_fops);
+
+static const struct drm_driver st7539_driver = {
+ .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
+ .fops = &st7539_fops,
+ DRM_GEM_DMA_DRIVER_OPS_VMAP,
+ .debugfs_init = mipi_dbi_debugfs_init,
+ .name = "st7539",
+ .desc = "Sitronix ST7539",
+ .date = "20240624",
+ .major = 1,
+ .minor = 0,
+};
+
+static const struct of_device_id st7539_of_match[] = {
+ { .compatible = "sitronix,st7539" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, st7539_of_match);
+
+static const struct spi_device_id st7539_id[] = {
+ { "st7539", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(spi, st7539_id);
+
+static int st7539_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct mipi_dbi_dev *dbidev;
+ struct drm_device *drm;
+ struct mipi_dbi *dbi;
+ struct gpio_desc *a0;
+ size_t bufsize;
+ int ret;
+
+ dbidev = devm_drm_dev_alloc(dev, &st7539_driver,
+ struct mipi_dbi_dev, drm);
+ if (IS_ERR(dbidev))
+ return PTR_ERR(dbidev);
+
+ dbi = &dbidev->dbi;
+ drm = &dbidev->drm;
+
+ bufsize = DIV_ROUND_UP(st7539_mode.vdisplay, 8) * st7539_mode.hdisplay;
+
+ dbi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(dbi->reset))
+ return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO 'reset'\n");
+
+ a0 = devm_gpiod_get(dev, "a0", GPIOD_OUT_LOW);
+ if (IS_ERR(a0))
+ return dev_err_probe(dev, PTR_ERR(a0), "Failed to get GPIO 'a0'\n");
+
+ ret = mipi_dbi_spi_init(spi, dbi, a0);
+ if (ret)
+ return ret;
+
+ /* override the command function set in mipi_dbi_spi_init() */
+ dbi->command = st7539_dbi_typec3_command;
+
+ /* Cannot read from this controller via SPI */
+ dbi->read_commands = NULL;
+
+ ret = mipi_dbi_dev_init_with_formats(dbidev, &st7539_pipe_funcs,
+ st7539_formats, ARRAY_SIZE(st7539_formats),
+ &st7539_mode, 0, bufsize);
+ if (ret)
+ return ret;
+
+ drm_mode_config_reset(drm);
+
+ ret = drm_dev_register(drm, 0);
+ if (ret)
+ return ret;
+
+ spi_set_drvdata(spi, drm);
+
+ drm_fbdev_dma_setup(drm, 0);
+
+ return 0;
+}
+
+static void st7539_remove(struct spi_device *spi)
+{
+ struct drm_device *drm = spi_get_drvdata(spi);
+
+ drm_dev_unplug(drm);
+ drm_atomic_helper_shutdown(drm);
+}
+
+static void st7539_shutdown(struct spi_device *spi)
+{
+ drm_atomic_helper_shutdown(spi_get_drvdata(spi));
+}
+
+static struct spi_driver st7539_spi_driver = {
+ .driver = {
+ .name = "st7539",
+ .of_match_table = st7539_of_match,
+ },
+ .id_table = st7539_id,
+ .probe = st7539_probe,
+ .remove = st7539_remove,
+ .shutdown = st7539_shutdown,
+};
+module_spi_driver(st7539_spi_driver);
+
+MODULE_DESCRIPTION("Sitronix ST7539 DRM driver");
+MODULE_AUTHOR("Christian Eggers <ceggers@arri.de>");
+MODULE_LICENSE("GPL");
Based on the existing ST7586 driver. But the ST7539 ... - is monochrome only - has 8 VERTICAL pixels per byte - doesn't support any MIPI DCS commands - has (a few) 16 bit commands - doesn't support setting a clipping rect when writing to the RAM - doesn't support rotation (only mirroring of X and/or Y axis) Questions/TODO: - should drivers for such old displays be mainlined? - shall I use mipi_dbi_ although the display doesn't implement MIPI DCS (and has some 16 bit commands)? - can the conversion to 8 vertical pixels/byte (taken from solomon/ssd130x.c) be avoided / simplified / made more efficient? - how to implement setting of the display contrast (required by my application)? - add device tree binding Signed-off-by: Christian Eggers <ceggers@arri.de> --- MAINTAINERS | 6 + drivers/gpu/drm/tiny/Kconfig | 11 + drivers/gpu/drm/tiny/Makefile | 1 + drivers/gpu/drm/tiny/st7539.c | 424 ++++++++++++++++++++++++++++++++++ 4 files changed, 442 insertions(+) create mode 100644 drivers/gpu/drm/tiny/st7539.c