drm/panel: Add driver for the Toppoly TD028TTEC1 panel

This panel is used on the OpenMoko Neo FreeRunner and Neo 1973.

The code is based on the omapdrm-specific panel-tpo-td028ttec1 driver.

v2:
- fix checkpatch warnings:
  o (lcd == NULL) => (!lcd) (sam)
  o (1 << X) => BIT(X) (sam)

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20190813201101.30980-9-laurent.pinchart@ideasonboard.com

drivers/gpu/drm/panel/Kconfig

@@ -324,6 +324,14 @@ config DRM_PANEL_SONY_ACX565AKM
 	  Say Y here if you want to enable support for the Sony ACX565AKM
 	  800x600 3.5" panel (found on the Nokia N900).
 
+config DRM_PANEL_TPO_TD028TTEC1
+	tristate "Toppoly (TPO) TD028TTEC1 panel driver"
+	depends on OF && SPI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want to enable support for TPO TD028TTEC1 480x640
+	  2.8" panel (found on the OpenMoko Neo FreeRunner and Neo 1973).
+
 config DRM_PANEL_TPO_TPG110
 	tristate "TPO TPG 800x400 panel"
 	depends on OF && SPI && GPIOLIB

drivers/gpu/drm/panel/Makefile

@@ -34,5 +34,6 @@ obj-$(CONFIG_DRM_PANEL_SHARP_LS043T1LE01) += panel-sharp-ls043t1le01.o
 obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7701) += panel-sitronix-st7701.o
 obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V) += panel-sitronix-st7789v.o
 obj-$(CONFIG_DRM_PANEL_SONY_ACX565AKM) += panel-sony-acx565akm.o
+obj-$(CONFIG_DRM_PANEL_TPO_TD028TTEC1) += panel-tpo-td028ttec1.o
 obj-$(CONFIG_DRM_PANEL_TPO_TPG110) += panel-tpo-tpg110.o
 obj-$(CONFIG_DRM_PANEL_TRULY_NT35597_WQXGA) += panel-truly-nt35597.o

drivers/gpu/drm/panel/panel-sony-acx565akm.c

@@ -31,10 +31,10 @@
 #include <drm/drm_modes.h>
 #include <drm/drm_panel.h>
 
-#define CTRL_DISP_BRIGHTNESS_CTRL_ON		(1 << 5)
+#define CTRL_DISP_BRIGHTNESS_CTRL_ON		BIT(5)
-#define CTRL_DISP_AMBIENT_LIGHT_CTRL_ON		(1 << 4)
+#define CTRL_DISP_AMBIENT_LIGHT_CTRL_ON		BIT(4)
-#define CTRL_DISP_BACKLIGHT_ON			(1 << 2)
+#define CTRL_DISP_BACKLIGHT_ON			BIT(2)
-#define CTRL_DISP_AUTO_BRIGHTNESS_ON		(1 << 1)
+#define CTRL_DISP_AUTO_BRIGHTNESS_ON		BIT(1)
 
 #define MIPID_CMD_WRITE_CABC		0x55
 #define MIPID_CMD_READ_CABC		0x56
@@ -621,7 +621,7 @@ static int acx565akm_probe(struct spi_device *spi)
 	int ret;
 
 	lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
-	if (lcd == NULL)
+	if (!lcd)
 		return -ENOMEM;
 
 	spi_set_drvdata(spi, lcd);

drivers/gpu/drm/panel/panel-tpo-td028ttec1.c

@@ -0,0 +1,399 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Toppoly TD028TTEC1 Panel Driver
+ *
+ * Copyright (C) 2019 Texas Instruments Incorporated
+ *
+ * Based on the omapdrm-specific panel-tpo-td028ttec1 driver
+ *
+ * Copyright (C) 2008 Nokia Corporation
+ * Author: Tomi Valkeinen <tomi.valkeinen@ti.com>
+ *
+ * Neo 1973 code (jbt6k74.c):
+ * Copyright (C) 2006-2007 OpenMoko, Inc.
+ * Author: Harald Welte <laforge@openmoko.org>
+ *
+ * Ported and adapted from Neo 1973 U-Boot by:
+ * H. Nikolaus Schaller <hns@goldelico.com>
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/module.h>
+#include <linux/spi/spi.h>
+
+#include <drm/drm_connector.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+
+#define JBT_COMMAND			0x000
+#define JBT_DATA			0x100
+
+#define JBT_REG_SLEEP_IN		0x10
+#define JBT_REG_SLEEP_OUT		0x11
+
+#define JBT_REG_DISPLAY_OFF		0x28
+#define JBT_REG_DISPLAY_ON		0x29
+
+#define JBT_REG_RGB_FORMAT		0x3a
+#define JBT_REG_QUAD_RATE		0x3b
+
+#define JBT_REG_POWER_ON_OFF		0xb0
+#define JBT_REG_BOOSTER_OP		0xb1
+#define JBT_REG_BOOSTER_MODE		0xb2
+#define JBT_REG_BOOSTER_FREQ		0xb3
+#define JBT_REG_OPAMP_SYSCLK		0xb4
+#define JBT_REG_VSC_VOLTAGE		0xb5
+#define JBT_REG_VCOM_VOLTAGE		0xb6
+#define JBT_REG_EXT_DISPL		0xb7
+#define JBT_REG_OUTPUT_CONTROL		0xb8
+#define JBT_REG_DCCLK_DCEV		0xb9
+#define JBT_REG_DISPLAY_MODE1		0xba
+#define JBT_REG_DISPLAY_MODE2		0xbb
+#define JBT_REG_DISPLAY_MODE		0xbc
+#define JBT_REG_ASW_SLEW		0xbd
+#define JBT_REG_DUMMY_DISPLAY		0xbe
+#define JBT_REG_DRIVE_SYSTEM		0xbf
+
+#define JBT_REG_SLEEP_OUT_FR_A		0xc0
+#define JBT_REG_SLEEP_OUT_FR_B		0xc1
+#define JBT_REG_SLEEP_OUT_FR_C		0xc2
+#define JBT_REG_SLEEP_IN_LCCNT_D	0xc3
+#define JBT_REG_SLEEP_IN_LCCNT_E	0xc4
+#define JBT_REG_SLEEP_IN_LCCNT_F	0xc5
+#define JBT_REG_SLEEP_IN_LCCNT_G	0xc6
+
+#define JBT_REG_GAMMA1_FINE_1		0xc7
+#define JBT_REG_GAMMA1_FINE_2		0xc8
+#define JBT_REG_GAMMA1_INCLINATION	0xc9
+#define JBT_REG_GAMMA1_BLUE_OFFSET	0xca
+
+#define JBT_REG_BLANK_CONTROL		0xcf
+#define JBT_REG_BLANK_TH_TV		0xd0
+#define JBT_REG_CKV_ON_OFF		0xd1
+#define JBT_REG_CKV_1_2			0xd2
+#define JBT_REG_OEV_TIMING		0xd3
+#define JBT_REG_ASW_TIMING_1		0xd4
+#define JBT_REG_ASW_TIMING_2		0xd5
+
+#define JBT_REG_HCLOCK_VGA		0xec
+#define JBT_REG_HCLOCK_QVGA		0xed
+
+struct td028ttec1_panel {
+	struct drm_panel panel;
+
+	struct spi_device *spi;
+	struct backlight_device *backlight;
+};
+
+#define to_td028ttec1_device(p) container_of(p, struct td028ttec1_panel, panel)
+
+static int jbt_ret_write_0(struct td028ttec1_panel *lcd, u8 reg, int *err)
+{
+	struct spi_device *spi = lcd->spi;
+	u16 tx_buf = JBT_COMMAND | reg;
+	int ret;
+
+	if (err && *err)
+		return *err;
+
+	ret = spi_write(spi, (u8 *)&tx_buf, sizeof(tx_buf));
+	if (ret < 0) {
+		dev_err(&spi->dev, "%s: SPI write failed: %d\n", __func__, ret);
+		if (err)
+			*err = ret;
+	}
+
+	return ret;
+}
+
+static int jbt_reg_write_1(struct td028ttec1_panel *lcd,
+			   u8 reg, u8 data, int *err)
+{
+	struct spi_device *spi = lcd->spi;
+	u16 tx_buf[2];
+	int ret;
+
+	if (err && *err)
+		return *err;
+
+	tx_buf[0] = JBT_COMMAND | reg;
+	tx_buf[1] = JBT_DATA | data;
+
+	ret = spi_write(spi, (u8 *)tx_buf, sizeof(tx_buf));
+	if (ret < 0) {
+		dev_err(&spi->dev, "%s: SPI write failed: %d\n", __func__, ret);
+		if (err)
+			*err = ret;
+	}
+
+	return ret;
+}
+
+static int jbt_reg_write_2(struct td028ttec1_panel *lcd,
+			   u8 reg, u16 data, int *err)
+{
+	struct spi_device *spi = lcd->spi;
+	u16 tx_buf[3];
+	int ret;
+
+	if (err && *err)
+		return *err;
+
+	tx_buf[0] = JBT_COMMAND | reg;
+	tx_buf[1] = JBT_DATA | (data >> 8);
+	tx_buf[2] = JBT_DATA | (data & 0xff);
+
+	ret = spi_write(spi, (u8 *)tx_buf, sizeof(tx_buf));
+	if (ret < 0) {
+		dev_err(&spi->dev, "%s: SPI write failed: %d\n", __func__, ret);
+		if (err)
+			*err = ret;
+	}
+
+	return ret;
+}
+
+static int td028ttec1_prepare(struct drm_panel *panel)
+{
+	struct td028ttec1_panel *lcd = to_td028ttec1_device(panel);
+	unsigned int i;
+	int ret = 0;
+
+	/* Three times command zero */
+	for (i = 0; i < 3; ++i) {
+		jbt_ret_write_0(lcd, 0x00, &ret);
+		usleep_range(1000, 2000);
+	}
+
+	/* deep standby out */
+	jbt_reg_write_1(lcd, JBT_REG_POWER_ON_OFF, 0x17, &ret);
+
+	/* RGB I/F on, RAM write off, QVGA through, SIGCON enable */
+	jbt_reg_write_1(lcd, JBT_REG_DISPLAY_MODE, 0x80, &ret);
+
+	/* Quad mode off */
+	jbt_reg_write_1(lcd, JBT_REG_QUAD_RATE, 0x00, &ret);
+
+	/* AVDD on, XVDD on */
+	jbt_reg_write_1(lcd, JBT_REG_POWER_ON_OFF, 0x16, &ret);
+
+	/* Output control */
+	jbt_reg_write_2(lcd, JBT_REG_OUTPUT_CONTROL, 0xfff9, &ret);
+
+	/* Sleep mode off */
+	jbt_ret_write_0(lcd, JBT_REG_SLEEP_OUT, &ret);
+
+	/* at this point we have like 50% grey */
+
+	/* initialize register set */
+	jbt_reg_write_1(lcd, JBT_REG_DISPLAY_MODE1, 0x01, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_DISPLAY_MODE2, 0x00, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_RGB_FORMAT, 0x60, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_DRIVE_SYSTEM, 0x10, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_BOOSTER_OP, 0x56, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_BOOSTER_MODE, 0x33, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_BOOSTER_FREQ, 0x11, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_BOOSTER_FREQ, 0x11, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_OPAMP_SYSCLK, 0x02, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_VSC_VOLTAGE, 0x2b, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_VCOM_VOLTAGE, 0x40, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_EXT_DISPL, 0x03, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_DCCLK_DCEV, 0x04, &ret);
+	/*
+	 * default of 0x02 in JBT_REG_ASW_SLEW responsible for 72Hz requirement
+	 * to avoid red / blue flicker
+	 */
+	jbt_reg_write_1(lcd, JBT_REG_ASW_SLEW, 0x04, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_DUMMY_DISPLAY, 0x00, &ret);
+
+	jbt_reg_write_1(lcd, JBT_REG_SLEEP_OUT_FR_A, 0x11, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_SLEEP_OUT_FR_B, 0x11, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_SLEEP_OUT_FR_C, 0x11, &ret);
+	jbt_reg_write_2(lcd, JBT_REG_SLEEP_IN_LCCNT_D, 0x2040, &ret);
+	jbt_reg_write_2(lcd, JBT_REG_SLEEP_IN_LCCNT_E, 0x60c0, &ret);
+	jbt_reg_write_2(lcd, JBT_REG_SLEEP_IN_LCCNT_F, 0x1020, &ret);
+	jbt_reg_write_2(lcd, JBT_REG_SLEEP_IN_LCCNT_G, 0x60c0, &ret);
+
+	jbt_reg_write_2(lcd, JBT_REG_GAMMA1_FINE_1, 0x5533, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_GAMMA1_FINE_2, 0x00, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_GAMMA1_INCLINATION, 0x00, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_GAMMA1_BLUE_OFFSET, 0x00, &ret);
+
+	jbt_reg_write_2(lcd, JBT_REG_HCLOCK_VGA, 0x1f0, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_BLANK_CONTROL, 0x02, &ret);
+	jbt_reg_write_2(lcd, JBT_REG_BLANK_TH_TV, 0x0804, &ret);
+
+	jbt_reg_write_1(lcd, JBT_REG_CKV_ON_OFF, 0x01, &ret);
+	jbt_reg_write_2(lcd, JBT_REG_CKV_1_2, 0x0000, &ret);
+
+	jbt_reg_write_2(lcd, JBT_REG_OEV_TIMING, 0x0d0e, &ret);
+	jbt_reg_write_2(lcd, JBT_REG_ASW_TIMING_1, 0x11a4, &ret);
+	jbt_reg_write_1(lcd, JBT_REG_ASW_TIMING_2, 0x0e, &ret);
+
+	return ret;
+}
+
+static int td028ttec1_enable(struct drm_panel *panel)
+{
+	struct td028ttec1_panel *lcd = to_td028ttec1_device(panel);
+	int ret;
+
+	ret = jbt_ret_write_0(lcd, JBT_REG_DISPLAY_ON, NULL);
+	if (ret)
+		return ret;
+
+	backlight_enable(lcd->backlight);
+
+	return 0;
+}
+
+static int td028ttec1_disable(struct drm_panel *panel)
+{
+	struct td028ttec1_panel *lcd = to_td028ttec1_device(panel);
+
+	backlight_disable(lcd->backlight);
+
+	jbt_ret_write_0(lcd, JBT_REG_DISPLAY_OFF, NULL);
+
+	return 0;
+}
+
+static int td028ttec1_unprepare(struct drm_panel *panel)
+{
+	struct td028ttec1_panel *lcd = to_td028ttec1_device(panel);
+
+	jbt_reg_write_2(lcd, JBT_REG_OUTPUT_CONTROL, 0x8002, NULL);
+	jbt_ret_write_0(lcd, JBT_REG_SLEEP_IN, NULL);
+	jbt_reg_write_1(lcd, JBT_REG_POWER_ON_OFF, 0x00, NULL);
+
+	return 0;
+}
+
+static const struct drm_display_mode td028ttec1_mode = {
+	.clock = 22153,
+	.hdisplay = 480,
+	.hsync_start = 480 + 24,
+	.hsync_end = 480 + 24 + 8,
+	.htotal = 480 + 24 + 8 + 8,
+	.vdisplay = 640,
+	.vsync_start = 640 + 4,
+	.vsync_end = 640 + 4 + 2,
+	.vtotal = 640 + 4 + 2 + 2,
+	.vrefresh = 66,
+	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+	.flags = DRM_MODE_FLAG_NHSYNC | DRM_MODE_FLAG_NVSYNC,
+	.width_mm = 43,
+	.height_mm = 58,
+};
+
+static int td028ttec1_get_modes(struct drm_panel *panel)
+{
+	struct drm_connector *connector = panel->connector;
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(panel->drm, &td028ttec1_mode);
+	if (!mode)
+		return -ENOMEM;
+
+	drm_mode_set_name(mode);
+	drm_mode_probed_add(connector, mode);
+
+	connector->display_info.width_mm = td028ttec1_mode.width_mm;
+	connector->display_info.height_mm = td028ttec1_mode.height_mm;
+	/*
+	 * FIXME: According to the datasheet sync signals are sampled on the
+	 * rising edge of the clock, but the code running on the OpenMoko Neo
+	 * FreeRunner and Neo 1973 indicates sampling on the falling edge. This
+	 * should be tested on a real device.
+	 */
+	connector->display_info.bus_flags = DRM_BUS_FLAG_DE_HIGH
+					  | DRM_BUS_FLAG_SYNC_SAMPLE_NEGEDGE
+					  | DRM_BUS_FLAG_PIXDATA_SAMPLE_POSEDGE;
+
+	return 1;
+}
+
+static const struct drm_panel_funcs td028ttec1_funcs = {
+	.prepare = td028ttec1_prepare,
+	.enable = td028ttec1_enable,
+	.disable = td028ttec1_disable,
+	.unprepare = td028ttec1_unprepare,
+	.get_modes = td028ttec1_get_modes,
+};
+
+static int td028ttec1_probe(struct spi_device *spi)
+{
+	struct td028ttec1_panel *lcd;
+	int ret;
+
+	lcd = devm_kzalloc(&spi->dev, sizeof(*lcd), GFP_KERNEL);
+	if (lcd == NULL)
+		return -ENOMEM;
+
+	spi_set_drvdata(spi, lcd);
+	lcd->spi = spi;
+
+	lcd->backlight = devm_of_find_backlight(&spi->dev);
+	if (IS_ERR(lcd->backlight))
+		return PTR_ERR(lcd->backlight);
+
+	spi->mode = SPI_MODE_3;
+	spi->bits_per_word = 9;
+
+	ret = spi_setup(spi);
+	if (ret < 0) {
+		dev_err(&spi->dev, "failed to setup SPI: %d\n", ret);
+		return ret;
+	}
+
+	drm_panel_init(&lcd->panel);
+	lcd->panel.dev = &lcd->spi->dev;
+	lcd->panel.funcs = &td028ttec1_funcs;
+
+	return drm_panel_add(&lcd->panel);
+}
+
+static int td028ttec1_remove(struct spi_device *spi)
+{
+	struct td028ttec1_panel *lcd = spi_get_drvdata(spi);
+
+	drm_panel_remove(&lcd->panel);
+	drm_panel_disable(&lcd->panel);
+	drm_panel_unprepare(&lcd->panel);
+
+	return 0;
+}
+
+static const struct of_device_id td028ttec1_of_match[] = {
+	{ .compatible = "tpo,td028ttec1", },
+	/* DT backward compatibility. */
+	{ .compatible = "toppoly,td028ttec1", },
+	{ /* sentinel */ },
+};
+
+MODULE_DEVICE_TABLE(of, td028ttec1_of_match);
+
+static const struct spi_device_id td028ttec1_ids[] = {
+	{ "tpo,td028ttec1", 0},
+	{ "toppoly,td028ttec1", 0 },
+	{ /* sentinel */ }
+};
+
+MODULE_DEVICE_TABLE(spi, td028ttec1_ids);
+
+static struct spi_driver td028ttec1_driver = {
+	.probe		= td028ttec1_probe,
+	.remove		= td028ttec1_remove,
+	.id_table	= td028ttec1_ids,
+	.driver		= {
+		.name   = "panel-tpo-td028ttec1",
+		.of_match_table = td028ttec1_of_match,
+	},
+};
+
+module_spi_driver(td028ttec1_driver);
+
+MODULE_AUTHOR("H. Nikolaus Schaller <hns@goldelico.com>");
+MODULE_DESCRIPTION("Toppoly TD028TTEC1 panel driver");
+MODULE_LICENSE("GPL");