Re: [PATCH v1 2/2] drm/tinydrm: add driver for ST7735R panels
From: Noralf TrÃnnes
Date: Wed Dec 06 2017 - 13:28:01 EST
Den 29.11.2017 04.01, skrev David Lechner:
This adds a new driver for Sitronix ST7735R display panels.
This has been tested using an Adafruit 1.8" TFT.
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/st7735r.c | 237 ++++++++++++++++++++++++++++++++++++++
4 files changed, 254 insertions(+)
create mode 100644 drivers/gpu/drm/tinydrm/st7735r.c
diff --git a/MAINTAINERS b/MAINTAINERS
index a174632..9c7707e 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -4462,6 +4462,12 @@ S: Maintained
F: drivers/gpu/drm/tinydrm/st7586.c
F: Documentation/devicetree/bindings/display/st7586.txt
+DRM DRIVER FOR SITRONIX ST7735R PANELS
+M: David Lechner <david@xxxxxxxxxxxxxx>
I know we haven't done this in the other tinydrm drivers, but I think
we should start adding which tree the development is happening in:
T:ÂÂÂ git git://anongit.freedesktop.org/drm/drm-misc
+S: Maintained
+F: drivers/gpu/drm/tinydrm/st7735r.c
+F: Documentation/devicetree/bindings/display/st7735r.txt
+
DRM DRIVER FOR TDFX VIDEO CARDS
S: Orphan / Obsolete
F: drivers/gpu/drm/tdfx/
diff --git a/drivers/gpu/drm/tinydrm/Kconfig b/drivers/gpu/drm/tinydrm/Kconfig
index 90c5bd5..b0e567d 100644
--- a/drivers/gpu/drm/tinydrm/Kconfig
+++ b/drivers/gpu/drm/tinydrm/Kconfig
@@ -52,3 +52,13 @@ config TINYDRM_ST7586
* LEGO MINDSTORMS EV3
If M is selected the module will be called st7586.
+
+config TINYDRM_ST7735R
+ tristate "DRM support for Sitronix ST7735R display panels"
+ depends on DRM_TINYDRM && SPI
+ select TINYDRM_MIPI_DBI
+ help
+ DRM driver Sitronix ST7735R with one of the following LCDs:
+ * JD-T18003-T01 1.8" 128x160 TFT
+
+ If M is selected the module will be called st7735r.
diff --git a/drivers/gpu/drm/tinydrm/Makefile b/drivers/gpu/drm/tinydrm/Makefile
index 8aeee53..49a1119 100644
--- a/drivers/gpu/drm/tinydrm/Makefile
+++ b/drivers/gpu/drm/tinydrm/Makefile
@@ -8,3 +8,4 @@ obj-$(CONFIG_TINYDRM_ILI9225) += ili9225.o
obj-$(CONFIG_TINYDRM_MI0283QT) += mi0283qt.o
obj-$(CONFIG_TINYDRM_REPAPER) += repaper.o
obj-$(CONFIG_TINYDRM_ST7586) += st7586.o
+obj-$(CONFIG_TINYDRM_ST7735R) += st7735r.o
diff --git a/drivers/gpu/drm/tinydrm/st7735r.c b/drivers/gpu/drm/tinydrm/st7735r.c
new file mode 100644
index 0000000..6435b00
--- /dev/null
+++ b/drivers/gpu/drm/tinydrm/st7735r.c
@@ -0,0 +1,237 @@
+/*
+ * DRM driver for Sitronix ST7735R 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/spi/spi.h>
+#include <video/mipi_display.h>
+
+#include <drm/drm_gem_framebuffer_helper.h>
+#include <drm/tinydrm/mipi-dbi.h>
+#include <drm/tinydrm/tinydrm-helpers.h>
+
+#define ST7735R_FRMCTR1 0xb1
+#define ST7735R_FRMCTR2 0xb2
+#define ST7735R_FRMCTR3 0xb3
+#define ST7735R_INVCTR 0xb4
+#define ST7735R_PWCTR1 0xc0
+#define ST7735R_PWCTR2 0xc1
+#define ST7735R_PWCTR3 0xc2
+#define ST7735R_PWCTR4 0xc3
+#define ST7735R_PWCTR5 0xc4
+#define ST7735R_VMCTR1 0xc5
+#define ST7735R_GAMCTRP1 0xe0
+#define ST7735R_GAMCTRN1 0xe1
+
+#define ST7735R_MY BIT(7)
+#define ST7735R_MX BIT(6)
+#define ST7735R_MV BIT(5)
+
+static void st7735r_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");
+
+ mipi_dbi_hw_reset(mipi);
+
+ ret = mipi_dbi_command(mipi, MIPI_DCS_SOFT_RESET);
+ if (ret) {
+ DRM_DEV_ERROR(dev, "Error sending command %d\n", ret);
+ return;
+ }
+
+ msleep(150);
+
+ mipi_dbi_command(mipi, MIPI_DCS_EXIT_SLEEP_MODE);
+ msleep(500);
+
+ mipi_dbi_command(mipi, ST7735R_FRMCTR1, 0x01, 0x2c, 0x2d);
+ mipi_dbi_command(mipi, ST7735R_FRMCTR2, 0x01, 0x2c, 0x2d);
+ mipi_dbi_command(mipi, ST7735R_FRMCTR3, 0x01, 0x2c, 0x2d, 0x01, 0x2c,
+ 0x2d);
+ mipi_dbi_command(mipi, ST7735R_INVCTR, 0x07);
+ mipi_dbi_command(mipi, ST7735R_PWCTR1, 0xa2, 0x02, 0x84);
+ mipi_dbi_command(mipi, ST7735R_PWCTR2, 0xc5);
+ mipi_dbi_command(mipi, ST7735R_PWCTR3, 0x0a, 0x00);
+ mipi_dbi_command(mipi, ST7735R_PWCTR4, 0x8a, 0x2a);
+ mipi_dbi_command(mipi, ST7735R_PWCTR5, 0x8a, 0xee);
+ mipi_dbi_command(mipi, ST7735R_VMCTR1, 0x0e);
+ mipi_dbi_command(mipi, MIPI_DCS_EXIT_INVERT_MODE);
+ switch (mipi->rotation) {
+ default:
+ addr_mode = ST7735R_MX | ST7735R_MY;
+ break;
+ case 90:
+ addr_mode = ST7735R_MX | ST7735R_MV;
+ break;
+ case 180:
+ addr_mode = 0;
+ break;
+ case 270:
+ addr_mode = ST7735R_MY | ST7735R_MV;
+ break;
+ }
+ mipi_dbi_command(mipi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode);
+ mipi_dbi_command(mipi, MIPI_DCS_SET_PIXEL_FORMAT,
+ MIPI_DCS_PIXEL_FMT_16BIT);
+ mipi_dbi_command(mipi, ST7735R_GAMCTRP1, 0x0f, 0x1a, 0x0f, 0x18, 0x2f,
+ 0x28, 0x20, 0x22, 0x1f, 0x1b, 0x23, 0x37, 0x00, 0x07,
+ 0x02, 0x10);
+ mipi_dbi_command(mipi, ST7735R_GAMCTRN1, 0x0f, 0x1b, 0x0f, 0x17, 0x33,
+ 0x2c, 0x29, 0x2e, 0x30, 0x30, 0x39, 0x3f, 0x00, 0x07,
+ 0x03, 0x10);
+ mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_ON);
+
+ msleep(100);
+
+ mipi_dbi_command(mipi, MIPI_DCS_ENTER_NORMAL_MODE);
+
+ msleep(10);
Please use 20ms here to avoid warning:
-:168: WARNING: msleep < 20ms can sleep for up to 20ms; see
Documentation/timers/timers-howto.txt
#168: FILE: drivers/gpu/drm/tinydrm/st7735r.c:107:
+ÂÂÂÂÂÂ msleep(10);
+
+ mipi->enabled = true;
+
+ if (fb)
+ fb->funcs->dirty(fb, NULL, 0, 0, NULL, 0);
+
+ tinydrm_enable_backlight(mipi->backlight);
The previous lines can be replaced with:
ÂÂÂ mipi_dbi_pipe_enable(pipe, crtc_state);
I want us to use helpers as much as possible, and in this case the
flushing will be reworked in the future so less places to touch when
that happens.
+}
+
+static void st7735r_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);
+
Please use mipi_dbi_pipe_disable() here.
+ DRM_DEBUG_KMS("\n");
+
+ if (!mipi->enabled)
+ return;
+
+ tinydrm_disable_backlight(mipi->backlight);
+
+ mipi_dbi_command(mipi, MIPI_DCS_SET_DISPLAY_OFF);
You turn off the panel, have you checked what it looks like if you don't
turn off backlight (which is optional in this driver)?
On the displays I have tried this on, all pixels turn white when they're
not driven, letting backlight through, giving an all white display.
That's why I have that blanking code in mipi_dbi_pipe_disable() when we
don't have backlight control and the reason I don't turn off the panel.
The power savings of not driving the panel is negligible AFAICR.
If you don't need DISPLAY_OFF, you can just use mipi_dbi_pipe_disable()
directly as the callback.
Noralf.
+
+ mipi->enabled = false;
+}
+
+static const struct drm_simple_display_pipe_funcs st7735r_pipe_funcs = {
+ .enable = st7735r_pipe_enable,
+ .disable = st7735r_pipe_disable,
+ .update = tinydrm_display_pipe_update,
+ .prepare_fb = tinydrm_display_pipe_prepare_fb,
+};
+
+static const struct drm_display_mode st7735r_mode = {
+ TINYDRM_MODE(128, 160, 28, 35),
+};
+
+DEFINE_DRM_GEM_CMA_FOPS(st7735r_fops);
+
+static struct drm_driver st7735r_driver = {
+ .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_PRIME |
+ DRIVER_ATOMIC,
+ .fops = &st7735r_fops,
+ TINYDRM_GEM_DRIVER_OPS,
+ .lastclose = tinydrm_lastclose,
+ .name = "st7735r",
+ .desc = "Sitronix ST7735R",
+ .date = "20171128",
+ .major = 1,
+ .minor = 0,
+};
+
+static const struct of_device_id st7735r_of_match[] = {
+ { .compatible = "sitronix,st7735r-jd-t18003-t01" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, st7735r_of_match);
+
+static const struct spi_device_id st7735r_id[] = {
+ { "st7735r-jd-t18003-t01", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(spi, st7735r_id);
+
+static int st7735r_probe(struct spi_device *spi)
+{
+ struct device *dev = &spi->dev;
+ 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;
+
+ mipi->reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(mipi->reset)) {
+ DRM_DEV_ERROR(dev, "Failed to get gpio 'reset'\n");
+ return PTR_ERR(mipi->reset);
+ }
+
+ dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW);
+ if (IS_ERR(dc)) {
+ DRM_DEV_ERROR(dev, "Failed to get gpio 'dc'\n");
+ return PTR_ERR(dc);
+ }
+
+ 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;
+
+ ret = mipi_dbi_init(&spi->dev, mipi, &st7735r_pipe_funcs,
+ &st7735r_driver, &st7735r_mode, rotation);
+ if (ret)
+ return ret;
+
+ spi_set_drvdata(spi, mipi);
+
+ return devm_tinydrm_register(&mipi->tinydrm);
+}
+
+static void st7735r_shutdown(struct spi_device *spi)
+{
+ struct mipi_dbi *mipi = spi_get_drvdata(spi);
+
+ tinydrm_shutdown(&mipi->tinydrm);
+}
+
+static struct spi_driver st7735r_spi_driver = {
+ .driver = {
+ .name = "st7735r",
+ .owner = THIS_MODULE,
+ .of_match_table = st7735r_of_match,
+ },
+ .id_table = st7735r_id,
+ .probe = st7735r_probe,
+ .shutdown = st7735r_shutdown,
+};
+module_spi_driver(st7735r_spi_driver);
+
+MODULE_DESCRIPTION("Sitronix ST7735R DRM driver");
+MODULE_AUTHOR("David Lechner <david@xxxxxxxxxxxxxx>");
+MODULE_LICENSE("GPL");