Re: [PATCH v3 4/6] drm/tinydrm: add support for LEGO MINDSTORMS EV3 LCD
From: Noralf TrÃnnes
Date: Sat Aug 05 2017 - 14:20:37 EST
Den 04.08.2017 00.33, skrev David Lechner:
LEGO MINDSTORMS EV3 has an LCD with a ST7586 controller. This adds a new
module for the ST7586 controller with parameters for the LEGO MINDSTORMS
EV3 LCD display.
Signed-off-by: David Lechner <david@xxxxxxxxxxxxxx>
---
MAINTAINERS | 6 +
drivers/gpu/drm/tinydrm/Kconfig | 10 +
drivers/gpu/drm/tinydrm/Makefile | 1 +
drivers/gpu/drm/tinydrm/st7586.c | 466 +++++++++++++++++++++++++++++++++++++++
4 files changed, 483 insertions(+)
create mode 100644 drivers/gpu/drm/tinydrm/st7586.c
diff --git a/MAINTAINERS b/MAINTAINERS
index a1e772e..9643f95 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4365,6 +4365,12 @@ S: Maintained
F: drivers/gpu/drm/tinydrm/repaper.c
F: Documentation/devicetree/bindings/display/repaper.txt
+DRM DRIVER FOR SITRONIX ST7586 PANELS
+M: David Lechner <david@xxxxxxxxxxxxxx>
+S: Maintained
+F: drivers/gpu/drm/tinydrm/st7586.c
+F: Documentation/devicetree/bindings/display/st7586.txt
+
This file is sorted alphabetically, so it should go after SIS.
It seems REPAPER ended up in the wrong place after the conflict
resolution following Linus's cleanup.
DRM DRIVER FOR RAGE 128 VIDEO CARDS
S: Orphan / Obsolete
F: drivers/gpu/drm/r128/
diff --git a/drivers/gpu/drm/tinydrm/Kconfig b/drivers/gpu/drm/tinydrm/Kconfig
index f17c3ca..2e790e7 100644
--- a/drivers/gpu/drm/tinydrm/Kconfig
+++ b/drivers/gpu/drm/tinydrm/Kconfig
@@ -32,3 +32,13 @@ config TINYDRM_REPAPER
2.71" TFT EPD Panel (E2271CS021)
If M is selected the module will be called repaper.
+
+config TINYDRM_ST7586
+ tristate "DRM support for Sitronix ST7586 display panels"
+ depends on DRM_TINYDRM && SPI
+ select TINYDRM_MIPI_DBI
+ help
+ DRM driver for the following Sitronix ST7586 panels:
+ * LEGO MINDSTORMS EV3
+
+ If M is selected the module will be called st7586.
diff --git a/drivers/gpu/drm/tinydrm/Makefile b/drivers/gpu/drm/tinydrm/Makefile
index 95bb4d4..0c184bd 100644
--- a/drivers/gpu/drm/tinydrm/Makefile
+++ b/drivers/gpu/drm/tinydrm/Makefile
@@ -6,3 +6,4 @@ obj-$(CONFIG_TINYDRM_MIPI_DBI) += mipi-dbi.o
# Displays
obj-$(CONFIG_TINYDRM_MI0283QT) += mi0283qt.o
obj-$(CONFIG_TINYDRM_REPAPER) += repaper.o
+obj-$(CONFIG_TINYDRM_ST7586) += st7586.o
diff --git a/drivers/gpu/drm/tinydrm/st7586.c b/drivers/gpu/drm/tinydrm/st7586.c
new file mode 100644
index 0000000..11e226d
--- /dev/null
+++ b/drivers/gpu/drm/tinydrm/st7586.c
@@ -0,0 +1,466 @@
+/*
+ * DRM driver for Sitronix ST7586 panels
+ *
+ * Copyright 2017 David Lechner <david@xxxxxxxxxxxxxx>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/delay.h>
+#include <linux/dma-buf.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/property.h>
+#include <linux/regulator/consumer.h>
+#include <linux/spi/spi.h>
+#include <video/mipi_display.h>
+
+#include <drm/tinydrm/mipi-dbi.h>
+#include <drm/tinydrm/tinydrm-helpers.h>
+
+/* controller-specific commands */
+#define ST7586_DISP_MODE_GRAY 0x38
+#define ST7586_DISP_MODE_MONO 0x39
+#define ST7586_ENABLE_DDRAM 0x3a
+#define ST7586_SET_DISP_DUTY 0xb0
+#define ST7586_SET_PART_DISP 0xb4
+#define ST7586_SET_NLINE_INV 0xb5
+#define ST7586_SET_VOP 0xc0
+#define ST7586_SET_BIAS_SYSTEM 0xc3
+#define ST7586_SET_BOOST_LEVEL 0xc4
+#define ST7586_SET_VOP_OFFSET 0xc7
+#define ST7586_ENABLE_ANALOG 0xd0
+#define ST7586_AUTO_READ_CTRL 0xd7
+#define ST7586_OTP_RW_CTRL 0xe0
+#define ST7586_OTP_CTRL_OUT 0xe1
+#define ST7586_OTP_READ 0xe3
+
+#define ST7586_DISP_CTRL_MX BIT(6)
+#define ST7586_DISP_CTRL_MY BIT(7)
+
+static void st7586_xrgb8888_to_gray332(u8 *dst, void *vaddr,
Could you put a comment somewhere explaining what grey332 means, that
it's not
a 332 pixel format that I first thought, but that you store 3x 2-bit
pixles in one byte.
+ struct drm_framebuffer *fb,
+ struct drm_clip_rect *clip)
+{
+ size_t len = (clip->x2 - clip->x1) * (clip->y2 - clip->y1);
+ unsigned int x, y;
+ u8 *src, *buf, val;
+
+ /* 3 pixels per byte, so grow clip to nearest multiple of 3 */
+ clip->x1 = clip->x1 / 3 * 3;
Something wrong here: 3 * 3.
+ clip->x2 = (clip->x2 + 2) / 3 * 3;
You can use DIV_ROUND_UP().
+
+ buf = kmalloc(len, GFP_KERNEL);
+ if (!buf)
+ return;
+
+ tinydrm_xrgb8888_to_gray8(buf, vaddr, fb, clip);
+ src = buf;
+
+ for (y = clip->y1; y < clip->y2; y++) {
+ for (x = clip->x1; x < clip->x2; x += 3) {
+ val = *src++ & 0xc0;
+ if (val & 0xc0)
+ val |= 0x20;
+ val |= (*src++ & 0xc0) >> 3;
+ if (val & 0x18)
+ val |= 0x04;
+ val |= *src++ >> 6;
+ *dst++ = ~val;
I don't understand how this pixel packing matches the one described in
the datasheet. Why do you flip the bits at the end?
+ }
+ }
+
+ /* now adjust the clip so it applies to dst */
+ clip->x1 /= 3;
+ clip->x2 /= 3;
+
+ kfree(buf);
+}
+
+static int st7586_buf_copy(void *dst, struct drm_framebuffer *fb,
+ struct drm_clip_rect *clip)
+{
+ struct drm_gem_cma_object *cma_obj = drm_fb_cma_get_gem_obj(fb, 0);
+ struct dma_buf_attachment *import_attach = cma_obj->base.import_attach;
+ struct drm_format_name_buf format_name;
+ void *src = cma_obj->vaddr;
+ int ret = 0;
+
+ if (import_attach) {
+ ret = dma_buf_begin_cpu_access(import_attach->dmabuf,
+ DMA_FROM_DEVICE);
+ if (ret)
+ return ret;
+ }
+
+ switch (fb->format->format) {
+ case DRM_FORMAT_XRGB8888:
+ st7586_xrgb8888_to_gray332(dst, src, fb, clip);
+ break;
+ default:
+ dev_err_once(fb->dev->dev, "Format is not supported: %s\n",
+ drm_get_format_name(fb->format->format,
+ &format_name));
+ ret = -EINVAL;
+ break;
You don't need this default, because you can only get the ones in
st7586_formats.
+ }
+
+ if (import_attach)
+ dma_buf_end_cpu_access(import_attach->dmabuf, DMA_FROM_DEVICE);
ret = dma_buf_end_cpu_access(...)
+
+ return ret;
+}
+
+static int st7586_fb_dirty(struct drm_framebuffer *fb,
+ struct drm_file *file_priv, unsigned int flags,
+ unsigned int color, struct drm_clip_rect *clips,
+ unsigned int num_clips)
+{
+ struct tinydrm_device *tdev = fb->dev->dev_private;
+ struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
+ struct drm_clip_rect clip;
+ int ret = 0;
+
+ mutex_lock(&tdev->dirty_lock);
+
+ if (!mipi->enabled)
+ goto out_unlock;
+
+ /* fbdev can flush even when we're not interested */
+ if (tdev->pipe.plane.fb != fb)
+ goto out_unlock;
+
+ tinydrm_merge_clips(&clip, clips, num_clips, flags, fb->width,
+ fb->height);
+
+ DRM_DEBUG("Flushing [FB:%d] x1=%u, x2=%u, y1=%u, y2=%u\n", fb->base.id,
+ clip.x1, clip.x2, clip.y1, clip.y2);
+
+ ret = st7586_buf_copy(mipi->tx_buf, fb, &clip);
+ if (ret)
+ goto out_unlock;
+
+ /* NB: st7586_buf_copy() modifies clip */
+
+ mipi_dbi_command(mipi, MIPI_DCS_SET_COLUMN_ADDRESS,
+ (clip.x1 >> 8) & 0xFF, clip.x1 & 0xFF,
+ (clip.x2 >> 8) & 0xFF, (clip.x2 - 1) & 0xFF);
+ mipi_dbi_command(mipi, MIPI_DCS_SET_PAGE_ADDRESS,
+ (clip.y1 >> 8) & 0xFF, clip.y1 & 0xFF,
+ (clip.y2 >> 8) & 0xFF, (clip.y2 - 1) & 0xFF);
+
+ ret = mipi_dbi_command_buf(mipi, MIPI_DCS_WRITE_MEMORY_START,
+ (u8 *)mipi->tx_buf,
+ (clip.x2 - clip.x1) * (clip.y2 - clip.y1));
+
+out_unlock:
+ mutex_unlock(&tdev->dirty_lock);
+
+ if (ret)
+ dev_err_once(fb->dev->dev, "Failed to update display %d\n",
+ ret);
+
+ return ret;
+}
+
+static const struct drm_framebuffer_funcs st7586_fb_funcs = {
+ .destroy = drm_fb_cma_destroy,
+ .create_handle = drm_fb_cma_create_handle,
+ .dirty = st7586_fb_dirty,
+};
+
+void st7586_pipe_enable(struct drm_simple_display_pipe *pipe,
+ struct drm_crtc_state *crtc_state)
+{
+ struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
+ struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
+ struct drm_framebuffer *fb = pipe->plane.fb;
+ struct device *dev = tdev->drm->dev;
+ int ret;
+ u8 addr_mode;
+
+ DRM_DEBUG_KMS("\n");
+
+ ret = regulator_enable(mipi->regulator);
+ if (ret) {
+ dev_err(dev, "Failed to enable regulator %d\n", ret);
+ return;
+ }
+
+ mipi_dbi_hw_reset(mipi);
+ ret = mipi_dbi_command(mipi, ST7586_AUTO_READ_CTRL, 0x9f);
+ if (ret) {
+ dev_err(dev, "Error sending command %d\n", ret);
+ regulator_disable(mipi->regulator);
+ return;
+ }
+
+ mipi_dbi_command(mipi, ST7586_OTP_RW_CTRL, 0x00);
+
+ msleep(10);
+
+ mipi_dbi_command(mipi, ST7586_OTP_READ);
+
+ msleep(20);
+
+ mipi_dbi_command(mipi, ST7586_OTP_CTRL_OUT);
+ mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
+ mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
+
+ msleep(50);
+
+ mipi_dbi_command(mipi, ST7586_SET_VOP_OFFSET, 0x00);
+ mipi_dbi_command(mipi, ST7586_SET_VOP, 0xe3, 0x00);
+ mipi_dbi_command(mipi, ST7586_SET_BIAS_SYSTEM, 0x02);
+ mipi_dbi_command(mipi, ST7586_SET_BOOST_LEVEL, 0x04);
+ mipi_dbi_command(mipi, ST7586_ENABLE_ANALOG, 0x1d);
+ mipi_dbi_command(mipi, ST7586_SET_NLINE_INV, 0x00);
+ mipi_dbi_command(mipi, ST7586_DISP_MODE_GRAY);
+ mipi_dbi_command(mipi, ST7586_ENABLE_DDRAM, 0x02);
+
+ switch (mipi->rotation) {
+ default:
+ addr_mode = 0x00;
+ break;
+ case 90:
+ addr_mode = ST7586_DISP_CTRL_MY;
+ break;
+ case 180:
+ addr_mode = ST7586_DISP_CTRL_MX | ST7586_DISP_CTRL_MY;
+ break;
+ case 270:
+ addr_mode = ST7586_DISP_CTRL_MX;
+ break;
+ }
+ mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
+
+ mipi_dbi_command(mipi, ST7586_SET_DISP_DUTY, 0x7f);
+ mipi_dbi_command(mipi, ST7586_SET_PART_DISP, 0xa0);
+ mipi_dbi_command(mipi, MIPI_DCS_SET_PARTIAL_AREA, 0x00, 0x00, 0x00, 0x77);
+ mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);
+
+ msleep(100);
+
+ mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
+
+ mipi->enabled = true;
+
+ if (fb)
+ fb->funcs->dirty(fb, NULL, 0, 0, NULL, 0);
+
+ tinydrm_enable_backlight(mipi->backlight);
+}
+
+static void st7586_pipe_disable(struct drm_simple_display_pipe *pipe)
+{
+ struct tinydrm_device *tdev = pipe_to_tinydrm(pipe);
+ struct mipi_dbi *mipi = mipi_dbi_from_tinydrm(tdev);
+
+ DRM_DEBUG_KMS("\n");
+
+ if (!mipi->enabled)
+ return;
+
+ mipi->enabled = false;
+ tinydrm_disable_backlight(mipi->backlight);
+ mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
+ regulator_disable(mipi->regulator);
+}
+
+static const u32 st7586_formats[] = {
+ DRM_FORMAT_XRGB8888,
+};
+
+static int st7586_init(struct device *dev, struct mipi_dbi *mipi,
+ const struct drm_simple_display_pipe_funcs *pipe_funcs,
+ struct drm_driver *driver, const struct drm_display_mode *mode,
+ unsigned int rotation)
+{
+ size_t bufsize = (mode->vdisplay + 2) / 3 * mode->hdisplay;
+ struct tinydrm_device *tdev = &mipi->tinydrm;
+ int ret;
+
+ mutex_init(&mipi->cmdlock);
+
+ mipi->tx_buf = devm_kmalloc(dev, bufsize, GFP_KERNEL);
+ if (!mipi->tx_buf)
+ return -ENOMEM;
+
+ ret = devm_tinydrm_init(dev, tdev, &st7586_fb_funcs, driver);
+ if (ret)
+ return ret;
+
+ ret = tinydrm_display_pipe_init(tdev, pipe_funcs,
+ DRM_MODE_CONNECTOR_VIRTUAL,
+ st7586_formats,
+ ARRAY_SIZE(st7586_formats),
+ mode, rotation);
+ if (ret)
+ return ret;
+
+ tdev->drm->mode_config.preferred_depth = 32;
+ mipi->rotation = rotation;
+
+ drm_mode_config_reset(tdev->drm);
+
+ DRM_DEBUG_KMS("preferred_depth=%u, rotation = %u\n",
+ tdev->drm->mode_config.preferred_depth, rotation);
+
+ return 0;
+}
+
+static const struct drm_simple_display_pipe_funcs st7586_pipe_funcs = {
+ .enable = st7586_pipe_enable,
+ .disable = st7586_pipe_disable,
+ .update = tinydrm_display_pipe_update,
+ .prepare_fb = tinydrm_display_pipe_prepare_fb,
+};
+
+static const struct drm_display_mode st7586_mode = {
+ TINYDRM_MODE(178, 128, 37, 27),
+};
+
+DEFINE_DRM_GEM_CMA_FOPS(st7586_fops);
+
+static struct drm_driver st7586_driver = {
+ .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
+ DRIVER_ATOMIC,
+ .fops = &st7586_fops,
+ TINYDRM_GEM_DRIVER_OPS,
+ .lastclose = tinydrm_lastclose,
+ .debugfs_init = mipi_dbi_debugfs_init,
+ .name = "st7586",
+ .desc = "Sitronix ST7586",
+ .date = "20170801",
+ .major = 1,
+ .minor = 0,
+};
+
+static const struct of_device_id st7586_of_match[] = {
+ { .compatible = "lego,ev3-lcd" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, st7586_of_match);
+
+static const struct spi_device_id st7586_id[] = {
+ { "ev3-lcd", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(spi, st7586_id);
+
+static int st7586_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ struct tinydrm_device *tdev;
+ struct mipi_dbi *mipi;
+ struct gpio_desc *dc;
+ u32 rotation = 0;
+ int ret;
+
+ mipi = devm_kzalloc(dev, sizeof(*mipi), GFP_KERNEL);
+ if (!mipi)
+ return -ENOMEM;
+
reset and dc is required following our discussion:
+ mipi->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(mipi->reset)) {
+ dev_err(dev, "Failed to get gpio 'reset'\n");
+ return PTR_ERR(mipi->reset);
+ }
+
+ dc = devm_gpiod_get_optional(dev, "dc", GPIOD_OUT_LOW);
+ if (IS_ERR(dc)) {
+ dev_err(dev, "Failed to get gpio 'dc'\n");
+ return PTR_ERR(dc);
+ }
+
+ mipi->regulator = devm_regulator_get(dev, "power");
+ if (IS_ERR(mipi->regulator))
+ return PTR_ERR(mipi->regulator);
+
+ mipi->backlight = tinydrm_of_find_backlight(dev);
+ if (IS_ERR(mipi->backlight))
+ return PTR_ERR(mipi->backlight);
+
+ device_property_read_u32(dev, "rotation", &rotation);
+
+ ret = mipi_dbi_spi_init(spi, mipi, dc);
+ if (ret)
+ return ret;
+
+ /* Cannot read from this controller via SPI */
+ mipi->read_commands = NULL;
+
+ /*
+ * we are using 8-bit data, so we are not actually swapping anything,
+ * but setting mipi->swap_bytes makes mipi_dbi_typec3_command() do the
+ * right thing and not use 16-bit transfers (which results in swapped
+ * bytes on little-endian systems and causes out of order data to be
+ * sent to the display).
+ */
+ mipi->swap_bytes = true;
+
+ ret = st7586_init(&spi->dev, mipi, &st7586_pipe_funcs, &st7586_driver,
+ &st7586_mode, rotation);
+ if (ret)
+ return ret;
+
+ tdev = &mipi->tinydrm;
+
+ ret = devm_tinydrm_register(tdev);
+ if (ret)
+ return ret;
+
+ spi_set_drvdata(spi, mipi);
+
+ DRM_DEBUG_DRIVER("Initialized %s:%s @%uMHz on minor %d\n",
+ tdev->drm->driver->name, dev_name(dev),
+ spi->max_speed_hz / 1000000,
+ tdev->drm->primary->index);
+
+ return 0;
+}
+
+static void st7586_shutdown(struct spi_device *spi)
+{
+ struct mipi_dbi *mipi = spi_get_drvdata(spi);
+
+ tinydrm_shutdown(&mipi->tinydrm);
+}
+
+static int __maybe_unused st7586_pm_suspend(struct device *dev)
+{
+ struct mipi_dbi *mipi = dev_get_drvdata(dev);
+
+ return tinydrm_suspend(&mipi->tinydrm);
+}
+
+static int __maybe_unused st7586_pm_resume(struct device *dev)
+{
+ struct mipi_dbi *mipi = dev_get_drvdata(dev);
+
+ return tinydrm_resume(&mipi->tinydrm);
+}
+
+static const struct dev_pm_ops st7586_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(st7586_pm_suspend, st7586_pm_resume)
+};
I checked davinci_all_defconfig and CONFIG_PM is not set.
If the board can't suspend, then you don't need this.
+
+static struct spi_driver st7586_spi_driver = {
+ .driver = {
+ .name = "st7586",
+ .owner = THIS_MODULE,
+ .of_match_table = st7586_of_match,
+ .pm = &st7586_pm_ops,
+ },
+ .id_table = st7586_id,
+ .probe = st7586_probe,
+ .shutdown = st7586_shutdown,
+};
+module_spi_driver(st7586_spi_driver);
+
+MODULE_DESCRIPTION("Sitronix ST7586 DRM driver");
+MODULE_AUTHOR("David Lechner <david@xxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL");