[U-Boot] [PATCH v7 07/16] tegra: Add LCD driver
Simon Glass
sjg at chromium.org
Thu Oct 18 01:24:51 CEST 2012
This driver supports driving a single LCD and providing a U-Boot console
on it.
Signed-off-by: Simon Glass <sjg at chromium.org>
---
Changes in v7:
- Add cast on call to tegra_display_probe()
Changes in v6:
- Add an additional delay before enabling the panel
- Don't access beyond end of config.panel_timings[]
- Set LCD frame buffer to correct address
Changes in v4:
- Rebase on top of new tegra common directory structure
- Change LCD panel GPIOs to be entirely optional
- Only indicate that LCD init is complete when all stages complete
Changes in v3:
- Move some fdt decode code from LCD driver to SOC display driver
- Rename fdt config structures
- Use new pwm binding from pre-linux-next
- Adjust LCD driver to use new SOC display driver structures
Changes in v2:
- Update LCD driver to deal with new fdt bindings
drivers/video/Makefile | 1 +
drivers/video/tegra.c | 368 ++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 369 insertions(+), 0 deletions(-)
create mode 100644 drivers/video/tegra.c
diff --git a/drivers/video/Makefile b/drivers/video/Makefile
index ebb6da8..78a7668 100644
--- a/drivers/video/Makefile
+++ b/drivers/video/Makefile
@@ -49,6 +49,7 @@ COBJS-$(CONFIG_VIDEO_OMAP3) += omap3_dss.o
COBJS-$(CONFIG_VIDEO_SED13806) += sed13806.o
COBJS-$(CONFIG_VIDEO_SM501) += sm501.o
COBJS-$(CONFIG_VIDEO_SMI_LYNXEM) += smiLynxEM.o videomodes.o
+COBJS-$(CONFIG_VIDEO_TEGRA) += tegra.o
COBJS-$(CONFIG_VIDEO_VCXK) += bus_vcxk.o
COBJS := $(sort $(COBJS-y))
diff --git a/drivers/video/tegra.c b/drivers/video/tegra.c
new file mode 100644
index 0000000..ab26ad0
--- /dev/null
+++ b/drivers/video/tegra.c
@@ -0,0 +1,368 @@
+/*
+ * Copyright (c) 2011 The Chromium OS Authors.
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * 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.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+#include <common.h>
+#include <fdtdec.h>
+#include <lcd.h>
+
+#include <asm/system.h>
+#include <asm/gpio.h>
+
+#include <asm/arch/clock.h>
+#include <asm/arch/funcmux.h>
+#include <asm/arch/pinmux.h>
+#include <asm/arch/pwm.h>
+#include <asm/arch/display.h>
+#include <asm/arch-tegra/timer.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+/* These are the stages we go throuh in enabling the LCD */
+enum stage_t {
+ STAGE_START,
+ STAGE_PANEL_VDD,
+ STAGE_LVDS,
+ STAGE_BACKLIGHT_VDD,
+ STAGE_PWM,
+ STAGE_BACKLIGHT_EN,
+ STAGE_DONE,
+};
+
+static enum stage_t stage; /* Current stage we are at */
+static unsigned long timer_next; /* Time we can move onto next stage */
+
+/* Our LCD config, set up in handle_stage() */
+static struct fdt_panel_config config;
+struct fdt_disp_config *disp_config; /* Display controller config */
+
+enum {
+ /* Maximum LCD size we support */
+ LCD_MAX_WIDTH = 1366,
+ LCD_MAX_HEIGHT = 768,
+ LCD_MAX_LOG2_BPP = 4, /* 2^4 = 16 bpp */
+};
+
+int lcd_line_length;
+int lcd_color_fg;
+int lcd_color_bg;
+
+void *lcd_base; /* Start of framebuffer memory */
+void *lcd_console_address; /* Start of console buffer */
+
+short console_col;
+short console_row;
+
+vidinfo_t panel_info = {
+ /* Insert a value here so that we don't end up in the BSS */
+ .vl_col = -1,
+};
+
+char lcd_cursor_enabled;
+
+ushort lcd_cursor_width;
+ushort lcd_cursor_height;
+
+#ifndef CONFIG_OF_CONTROL
+#error "You must enable CONFIG_OF_CONTROL to get Tegra LCD support"
+#endif
+
+void lcd_cursor_size(ushort width, ushort height)
+{
+ lcd_cursor_width = width;
+ lcd_cursor_height = height;
+}
+
+void lcd_toggle_cursor(void)
+{
+ ushort x, y;
+ uchar *dest;
+ ushort row;
+
+ x = console_col * lcd_cursor_width;
+ y = console_row * lcd_cursor_height;
+ dest = (uchar *)(lcd_base + y * lcd_line_length + x * (1 << LCD_BPP) /
+ 8);
+
+ for (row = 0; row < lcd_cursor_height; ++row, dest += lcd_line_length) {
+ ushort *d = (ushort *)dest;
+ ushort color;
+ int i;
+
+ for (i = 0; i < lcd_cursor_width; ++i) {
+ color = *d;
+ color ^= lcd_color_fg;
+ *d = color;
+ ++d;
+ }
+ }
+}
+
+void lcd_cursor_on(void)
+{
+ lcd_cursor_enabled = 1;
+ lcd_toggle_cursor();
+}
+void lcd_cursor_off(void)
+{
+ lcd_cursor_enabled = 0;
+ lcd_toggle_cursor();
+}
+
+char lcd_is_cursor_enabled(void)
+{
+ return lcd_cursor_enabled;
+}
+
+static void update_panel_size(struct fdt_disp_config *config)
+{
+ panel_info.vl_col = config->width;
+ panel_info.vl_row = config->height;
+ panel_info.vl_bpix = config->log2_bpp;
+}
+
+/*
+ * Main init function called by lcd driver.
+ * Inits and then prints test pattern if required.
+ */
+
+void lcd_ctrl_init(void *lcdbase)
+{
+ int line_length, size;
+
+ assert(disp_config);
+
+ lcd_base = (void *)disp_config->frame_buffer;
+
+ /* Make sure that we can acommodate the selected LCD */
+ assert(disp_config->width <= LCD_MAX_WIDTH);
+ assert(disp_config->height <= LCD_MAX_HEIGHT);
+ assert(disp_config->log2_bpp <= LCD_MAX_LOG2_BPP);
+ if (disp_config->width <= LCD_MAX_WIDTH
+ && disp_config->height <= LCD_MAX_HEIGHT
+ && disp_config->log2_bpp <= LCD_MAX_LOG2_BPP)
+ update_panel_size(disp_config);
+ size = lcd_get_size(&line_length);
+
+ debug("LCD frame buffer at %p\n", lcd_base);
+}
+
+ulong calc_fbsize(void)
+{
+ return (panel_info.vl_col * panel_info.vl_row *
+ NBITS(panel_info.vl_bpix)) / 8;
+}
+
+void lcd_setcolreg(ushort regno, ushort red, ushort green, ushort blue)
+{
+}
+
+void tegra_lcd_early_init(const void *blob)
+{
+ /*
+ * Go with the maximum size for now. We will fix this up after
+ * relocation. These values are only used for memory alocation.
+ */
+ panel_info.vl_col = LCD_MAX_WIDTH;
+ panel_info.vl_row = LCD_MAX_HEIGHT;
+ panel_info.vl_bpix = LCD_MAX_LOG2_BPP;
+}
+
+/**
+ * Decode the panel information from the fdt.
+ *
+ * @param blob fdt blob
+ * @param config structure to store fdt config into
+ * @return 0 if ok, -ve on error
+ */
+static int fdt_decode_lcd(const void *blob, struct fdt_panel_config *config)
+{
+ int display_node;
+
+ disp_config = tegra_display_get_config();
+ if (!disp_config) {
+ debug("%s: Display controller is not configured\n", __func__);
+ return -1;
+ }
+ display_node = disp_config->panel_node;
+ if (display_node < 0) {
+ debug("%s: No panel configuration available\n", __func__);
+ return -1;
+ }
+
+ config->pwm_channel = pwm_request(blob, display_node, "nvidia,pwm");
+ if (config->pwm_channel < 0) {
+ debug("%s: Unable to request PWM channel\n", __func__);
+ return -1;
+ }
+
+ config->cache_type = fdtdec_get_int(blob, display_node,
+ "nvidia,cache-type",
+ FDT_LCD_CACHE_WRITE_BACK_FLUSH);
+
+ /* These GPIOs are all optional */
+ fdtdec_decode_gpio(blob, display_node, "nvidia,backlight-enable-gpios",
+ &config->backlight_en);
+ fdtdec_decode_gpio(blob, display_node, "nvidia,lvds-shutdown-gpios",
+ &config->lvds_shutdown);
+ fdtdec_decode_gpio(blob, display_node, "nvidia,backlight-vdd-gpios",
+ &config->backlight_vdd);
+ fdtdec_decode_gpio(blob, display_node, "nvidia,panel-vdd-gpios",
+ &config->panel_vdd);
+
+ return fdtdec_get_int_array(blob, display_node, "nvidia,panel-timings",
+ config->panel_timings, FDT_LCD_TIMINGS);
+}
+
+/**
+ * Handle the next stage of device init
+ */
+static int handle_stage(const void *blob)
+{
+ debug("%s: stage %d\n", __func__, stage);
+
+ /* do the things for this stage */
+ switch (stage) {
+ case STAGE_START:
+ /* Initialize the Tegra display controller */
+ if (tegra_display_probe(gd->fdt_blob, (void *)gd->fb_base)) {
+ printf("%s: Failed to probe display driver\n",
+ __func__);
+ return -1;
+ }
+
+ /* get panel details */
+ if (fdt_decode_lcd(blob, &config)) {
+ printf("No valid LCD information in device tree\n");
+ return -1;
+ }
+
+ /*
+ * It is possible that the FDT has requested that the LCD be
+ * disabled. We currently don't support this. It would require
+ * changes to U-Boot LCD subsystem to have LCD support
+ * compiled in but not used. An easier option might be to
+ * still have a frame buffer, but leave the backlight off and
+ * remove all mention of lcd in the stdout environment
+ * variable.
+ */
+
+ funcmux_select(PERIPH_ID_DISP1, FUNCMUX_DEFAULT);
+
+ fdtdec_setup_gpio(&config.panel_vdd);
+ fdtdec_setup_gpio(&config.lvds_shutdown);
+ fdtdec_setup_gpio(&config.backlight_vdd);
+ fdtdec_setup_gpio(&config.backlight_en);
+
+ /*
+ * TODO: If fdt includes output flag we can omit this code
+ * since fdtdec_setup_gpio will do it for us.
+ */
+ if (fdt_gpio_isvalid(&config.panel_vdd))
+ gpio_direction_output(config.panel_vdd.gpio, 0);
+ if (fdt_gpio_isvalid(&config.lvds_shutdown))
+ gpio_direction_output(config.lvds_shutdown.gpio, 0);
+ if (fdt_gpio_isvalid(&config.backlight_vdd))
+ gpio_direction_output(config.backlight_vdd.gpio, 0);
+ if (fdt_gpio_isvalid(&config.backlight_en))
+ gpio_direction_output(config.backlight_en.gpio, 0);
+ break;
+ case STAGE_PANEL_VDD:
+ if (fdt_gpio_isvalid(&config.panel_vdd))
+ gpio_direction_output(config.panel_vdd.gpio, 1);
+ break;
+ case STAGE_LVDS:
+ if (fdt_gpio_isvalid(&config.lvds_shutdown))
+ gpio_set_value(config.lvds_shutdown.gpio, 1);
+ break;
+ case STAGE_BACKLIGHT_VDD:
+ if (fdt_gpio_isvalid(&config.backlight_vdd))
+ gpio_set_value(config.backlight_vdd.gpio, 1);
+ break;
+ case STAGE_PWM:
+ /* Enable PWM at 15/16 high, 32768 Hz with divider 1 */
+ pinmux_set_func(PINGRP_GPU, PMUX_FUNC_PWM);
+ pinmux_tristate_disable(PINGRP_GPU);
+
+ pwm_enable(config.pwm_channel, 32768, 0xdf, 1);
+ break;
+ case STAGE_BACKLIGHT_EN:
+ if (fdt_gpio_isvalid(&config.backlight_en))
+ gpio_set_value(config.backlight_en.gpio, 1);
+ break;
+ case STAGE_DONE:
+ break;
+ }
+
+ /* set up timer for next stage */
+ timer_next = timer_get_us();
+ if (stage < FDT_LCD_TIMINGS)
+ timer_next += config.panel_timings[stage] * 1000;
+
+ /* move to next stage */
+ stage++;
+ return 0;
+}
+
+int tegra_lcd_check_next_stage(const void *blob, int wait)
+{
+ if (stage == STAGE_DONE)
+ return 0;
+
+ do {
+ /* wait if we need to */
+ debug("%s: stage %d\n", __func__, stage);
+ if (stage != STAGE_START) {
+ int delay = timer_next - timer_get_us();
+
+ if (delay > 0) {
+ if (wait)
+ udelay(delay);
+ else
+ return 0;
+ }
+ }
+
+ if (handle_stage(blob))
+ return -1;
+ } while (wait && stage != STAGE_DONE);
+ if (stage == STAGE_DONE)
+ debug("%s: LCD init complete\n", __func__);
+
+ return 0;
+}
+
+void lcd_enable(void)
+{
+ /*
+ * Backlight and power init will be done separately in
+ * tegra_lcd_check_next_stage(), which should be called in
+ * board_late_init().
+ *
+ * U-Boot code supports only colour depth, selected at compile time.
+ * The device tree setting should match this. Otherwise the display
+ * will not look right, and U-Boot may crash.
+ */
+ if (disp_config->log2_bpp != LCD_BPP) {
+ printf("%s: Error: LCD depth configured in FDT (%d = %dbpp)"
+ " must match setting of LCD_BPP (%d)\n", __func__,
+ disp_config->log2_bpp, disp_config->bpp, LCD_BPP);
+ }
+}
--
1.7.7.3
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