[RFC 4/5] drm/tinydrm: Add mipi-dbi support
Noralf Trønnes
noralf at tronnes.org
Wed Mar 16 13:34:18 UTC 2016
Add support for MIPI DBI interfaced controllers.
Signed-off-by: Noralf Trønnes <noralf at tronnes.org>
---
drivers/gpu/drm/tinydrm/Kconfig | 3 +
drivers/gpu/drm/tinydrm/Makefile | 3 +
drivers/gpu/drm/tinydrm/mipi-dbi.c | 231 +++++++++++++++++++++++++++++++++++++
include/drm/tinydrm/mipi-dbi.h | 24 ++++
4 files changed, 261 insertions(+)
create mode 100644 drivers/gpu/drm/tinydrm/mipi-dbi.c
create mode 100644 include/drm/tinydrm/mipi-dbi.h
diff --git a/drivers/gpu/drm/tinydrm/Kconfig b/drivers/gpu/drm/tinydrm/Kconfig
index 671239f..a7929e0 100644
--- a/drivers/gpu/drm/tinydrm/Kconfig
+++ b/drivers/gpu/drm/tinydrm/Kconfig
@@ -10,4 +10,7 @@ menuconfig DRM_TINYDRM
Choose this option if you have a tinydrm supported display.
If M is selected the module will be called tinydrm.
+config TINYDRM_MIPI_DBI
+ tristate
+
source "drivers/gpu/drm/tinydrm/lcdreg/Kconfig"
diff --git a/drivers/gpu/drm/tinydrm/Makefile b/drivers/gpu/drm/tinydrm/Makefile
index f4a92d9..35ba822 100644
--- a/drivers/gpu/drm/tinydrm/Makefile
+++ b/drivers/gpu/drm/tinydrm/Makefile
@@ -1,2 +1,5 @@
obj-$(CONFIG_DRM_TINYDRM) += core/
obj-$(CONFIG_LCDREG) += lcdreg/
+
+# Controllers
+obj-$(CONFIG_TINYDRM_MIPI_DBI) += mipi-dbi.o
diff --git a/drivers/gpu/drm/tinydrm/mipi-dbi.c b/drivers/gpu/drm/tinydrm/mipi-dbi.c
new file mode 100644
index 0000000..3021349
--- /dev/null
+++ b/drivers/gpu/drm/tinydrm/mipi-dbi.c
@@ -0,0 +1,231 @@
+//#define DEBUG
+/*
+ * MIPI Display Bus Interface (DBI) LCD controller support
+ *
+ * Copyright 2016 Noralf Trønnes
+ *
+ * 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 <drm/drm_gem_cma_helper.h>
+#include <drm/tinydrm/lcdreg.h>
+#include <drm/tinydrm/tinydrm.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/swab.h>
+#include <video/mipi_display.h>
+
+#define DCS_POWER_MODE_DISPLAY BIT(2)
+#define DCS_POWER_MODE_DISPLAY_NORMAL_MODE BIT(3)
+#define DCS_POWER_MODE_SLEEP_MODE BIT(4)
+#define DCS_POWER_MODE_PARTIAL_MODE BIT(5)
+#define DCS_POWER_MODE_IDLE_MODE BIT(6)
+#define DCS_POWER_MODE_RESERVED_MASK (BIT(0) | BIT(1) | BIT(7))
+
+/* TODO: Move common functions to a separate module */
+void tinydrm_xrgb8888_to_rgb565(u32 *src, u16 *dst, unsigned num_pixels, bool swap_bytes)
+{
+ int i;
+
+ for (i = 0; i < num_pixels; i++) {
+ *dst = ((*src & 0x00F80000) >> 8) |
+ ((*src & 0x0000FC00) >> 5) |
+ ((*src & 0x000000F8) >> 3);
+ if (swap_bytes)
+ *dst = swab16(*dst);
+ src++;
+ dst++;
+ }
+}
+
+// TODO: Pass in regnr
+int tinydrm_update_rgb565_lcdreg(struct tinydrm_device *tdev, struct drm_framebuffer *fb, void *vmem, struct drm_clip_rect *clip)
+{
+ unsigned num_pixels = (clip->x2 - clip->x1 + 1) *
+ (clip->y2 - clip->y1 + 1);
+ struct lcdreg_transfer tr = {
+ .index = 1,
+ .width = 16,
+ .count = num_pixels
+ };
+ bool byte_swap = false;
+ u16 *buf = NULL;
+ int ret;
+
+ dev_err_once(tdev->base->dev, "pixel_format = %s, bpw = 0x%08x\n", drm_get_format_name(fb->pixel_format), tdev->lcdreg->bits_per_word_mask);
+
+ switch (fb->pixel_format) {
+ case DRM_FORMAT_RGB565:
+ tr.buf = vmem;
+ break;
+ case DRM_FORMAT_XRGB8888:
+ buf = kmalloc(num_pixels * sizeof(u16), GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+#if defined(__LITTLE_ENDIAN)
+ byte_swap = !lcdreg_bpw_supported(tdev->lcdreg, 16);
+#endif
+ tinydrm_xrgb8888_to_rgb565(vmem, buf, num_pixels, byte_swap);
+ tr.buf = buf;
+ if (byte_swap) {
+ tr.width = 8;
+ tr.count *= 2;
+ }
+ break;
+ default:
+ dev_err_once(tdev->base->dev,
+ "pixel_format '%s' is not supported\n",
+ drm_get_format_name(fb->pixel_format));
+ return -EINVAL;
+ }
+
+ ret = lcdreg_write(tdev->lcdreg, MIPI_DCS_WRITE_MEMORY_START, &tr);
+ kfree(buf);
+
+ return ret;
+}
+
+static void mipi_dbi_deferred_update(struct work_struct *work)
+{
+ struct tinydrm_device *tdev = work_to_tinydrm(work);
+ struct lcdreg *reg = tdev->lcdreg;
+ struct tinydrm_fb_clip fb_clip;
+ struct drm_clip_rect *clip = &fb_clip.clip;
+ int ret;
+
+ dev_dbg(tdev->base->dev, "%s\n", __func__);
+
+ if (!tinydrm_deferred_begin(tdev, &fb_clip))
+ return;
+
+ dev_dbg(tdev->base->dev, "%s: vmem=%p, x1=%u, x2=%u, y1=%u, y2=%u\n", __func__, fb_clip.vmem, clip->x1, clip->x2, clip->y1, clip->y2);
+
+ lcdreg_writereg(reg, MIPI_DCS_SET_COLUMN_ADDRESS,
+ (clip->x1 >> 8) & 0xFF, clip->x1 & 0xFF,
+ (clip->x2 >> 8) & 0xFF, clip->x2 & 0xFF);
+ lcdreg_writereg(reg, MIPI_DCS_SET_PAGE_ADDRESS,
+ (clip->y1 >> 8) & 0xFF, clip->y1 & 0xFF,
+ (clip->y2 >> 8) & 0xFF, clip->y2 & 0xFF);
+
+ ret = tinydrm_update_rgb565_lcdreg(tdev, fb_clip.fb, fb_clip.vmem, clip);
+ if (ret)
+ dev_err_once(tdev->base->dev, "Failed to update display %d\n", ret);
+
+ tinydrm_deferred_end(tdev);
+}
+
+int mipi_dbi_init(struct device *dev, struct tinydrm_device *tdev)
+{
+ tdev->deferred = devm_kzalloc(dev, sizeof(*tdev->deferred),
+ GFP_KERNEL);
+ if (!tdev->deferred)
+ return -ENOMEM;
+
+ INIT_DELAYED_WORK(&tdev->deferred->dwork, mipi_dbi_deferred_update);
+ tinydrm_reset_clip(&tdev->deferred->fb_clip.clip);
+ tdev->lcdreg->def_width = 8;
+ tdev->dirtyfb = tinydrm_dirtyfb;
+
+ return 0;
+}
+EXPORT_SYMBOL(mipi_dbi_init);
+
+/* Returns true if the display can be verified to be on */
+bool mipi_dbi_display_is_on(struct lcdreg *reg)
+{
+ u32 val;
+
+ if (!lcdreg_is_readable(reg))
+ return false;
+
+ if (lcdreg_readreg_buf32(reg, MIPI_DCS_GET_POWER_MODE, &val, 1))
+ return false;
+
+ val &= ~DCS_POWER_MODE_RESERVED_MASK;
+
+ if (val != (DCS_POWER_MODE_DISPLAY |
+ DCS_POWER_MODE_DISPLAY_NORMAL_MODE | DCS_POWER_MODE_SLEEP_MODE))
+ return false;
+
+ DRM_DEBUG_DRIVER("Display is ON\n");
+
+ return true;
+}
+EXPORT_SYMBOL(mipi_dbi_display_is_on);
+
+void mipi_dbi_debug_dump_regs(struct lcdreg *reg)
+{
+ u32 val[4];
+ int ret;
+
+ if (!(lcdreg_is_readable(reg) && (drm_debug & DRM_UT_DRIVER)))
+ return;
+
+ ret = lcdreg_readreg_buf32(reg, MIPI_DCS_GET_DISPLAY_ID, val, 3);
+ if (ret) {
+ dev_warn(reg->dev,
+ "failed to read from controller: %d", ret);
+ return;
+ }
+
+ /* RDDID is not part of the MIPI standard, but seems to be common */
+ DRM_DEBUG_DRIVER("Display ID (%02x): %02x %02x %02x\n",
+ MIPI_DCS_GET_DISPLAY_ID, val[0], val[1], val[2]);
+
+ lcdreg_readreg_buf32(reg, MIPI_DCS_GET_DISPLAY_STATUS, val, 4);
+ DRM_DEBUG_DRIVER("Display status (%02x): %02x %02x %02x %02x\n",
+ MIPI_DCS_GET_DISPLAY_STATUS, val[0], val[1], val[2], val[3]);
+
+ lcdreg_readreg_buf32(reg, MIPI_DCS_GET_POWER_MODE, val, 1);
+ DRM_DEBUG_DRIVER("Power mode (%02x): %02x\n",
+ MIPI_DCS_GET_POWER_MODE, val[0]);
+
+ lcdreg_readreg_buf32(reg, MIPI_DCS_GET_ADDRESS_MODE, val, 1);
+ DRM_DEBUG_DRIVER("Address mode (%02x): %02x\n",
+ MIPI_DCS_GET_ADDRESS_MODE, val[0]);
+
+ lcdreg_readreg_buf32(reg, MIPI_DCS_GET_PIXEL_FORMAT, val, 1);
+ DRM_DEBUG_DRIVER("Pixel format (%02x): %02x\n",
+ MIPI_DCS_GET_PIXEL_FORMAT, val[0]);
+
+ lcdreg_readreg_buf32(reg, MIPI_DCS_GET_DISPLAY_MODE, val, 1);
+ DRM_DEBUG_DRIVER("Display mode (%02x): %02x\n",
+ MIPI_DCS_GET_DISPLAY_MODE, val[0]);
+
+ lcdreg_readreg_buf32(reg, MIPI_DCS_GET_SIGNAL_MODE, val, 1);
+ DRM_DEBUG_DRIVER("Display signal mode (%02x): %02x\n",
+ MIPI_DCS_GET_SIGNAL_MODE, val[0]);
+
+ lcdreg_readreg_buf32(reg, MIPI_DCS_GET_DIAGNOSTIC_RESULT, val, 1);
+ DRM_DEBUG_DRIVER("Diagnostic result (%02x): %02x\n",
+ MIPI_DCS_GET_DIAGNOSTIC_RESULT, val[0]);
+}
+EXPORT_SYMBOL(mipi_dbi_debug_dump_regs);
+
+int mipi_dbi_panel_unprepare(struct drm_panel *panel)
+{
+ struct tinydrm_device *tdev = tinydrm_from_panel(panel);
+ struct lcdreg *reg = tdev->lcdreg;
+
+ /*
+ * Only do this if we have turned off backlight because if it's on the
+ * display will in most cases turn all white when the pixels are
+ * turned off.
+ */
+ if (tdev->backlight) {
+ lcdreg_writereg(reg, MIPI_DCS_SET_DISPLAY_OFF);
+ lcdreg_writereg(reg, MIPI_DCS_ENTER_SLEEP_MODE);
+ }
+
+ if (tdev->regulator)
+ regulator_disable(tdev->regulator);
+
+ return 0;
+}
+EXPORT_SYMBOL(mipi_dbi_panel_unprepare);
+
+MODULE_LICENSE("GPL");
diff --git a/include/drm/tinydrm/mipi-dbi.h b/include/drm/tinydrm/mipi-dbi.h
new file mode 100644
index 0000000..108a73b
--- /dev/null
+++ b/include/drm/tinydrm/mipi-dbi.h
@@ -0,0 +1,24 @@
+/*
+ * MIPI Display Bus Interface (DBI) LCD controller support
+ *
+ * Copyright 2016 Noralf Trønnes
+ *
+ * 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.
+ */
+
+#ifndef __LINUX_MIPI_DBI_H
+#define __LINUX_MIPI_DBI_H
+
+struct tinydrm_device;
+struct drm_panel;
+struct lcdreg;
+
+int mipi_dbi_init(struct device *dev, struct tinydrm_device *tdev);
+bool mipi_dbi_display_is_on(struct lcdreg *reg);
+void mipi_dbi_debug_dump_regs(struct lcdreg *reg);
+int mipi_dbi_panel_unprepare(struct drm_panel *panel);
+
+#endif /* __LINUX_MIPI_DBI_H */
--
2.2.2
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