tegra: Add LCD driver
authorSimon Glass <sjg@chromium.org>
Wed, 17 Oct 2012 13:24:51 +0000 (13:24 +0000)
committerTom Warren <twarren@nvidia.com>
Mon, 19 Nov 2012 15:15:37 +0000 (08:15 -0700)
This driver supports driving a single LCD and providing a U-Boot console
on it.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>
drivers/video/Makefile
drivers/video/tegra.c [new file with mode: 0644]

index 247b86782a6a3c3c3b6dd3a9954abec515193321..b3207c83c3cfc3089c4cbe8fa359f864b29e797c 100644 (file)
@@ -50,6 +50,7 @@ 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 (file)
index 0000000..ab26ad0
--- /dev/null
@@ -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);
+       }
+}