1 files changed, 214 insertions, 0 deletions

diff --git a/firmware/target/arm/imx31/gigabeat-s/backlight-gigabeat-s.c b/firmware/target/arm/imx31/gigabeat-s/backlight-gigabeat-s.c
new file mode 100644
index 0000000000..ec7bf7e8a9
--- /dev/null
+++ b/firmware/target/arm/imx31/gigabeat-s/backlight-gigabeat-s.c
@@ -0,0 +1,214 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2006 by Linus Nielsen Feltzing
+ *
+ * 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 software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "config.h"
+#include "system.h"
+#include "backlight.h"
+#include "mc13783.h"
+#include "backlight-target.h"
+#include "lcd.h"
+
+#ifdef HAVE_BACKLIGHT_BRIGHTNESS
+/* Table that uses combinations of current level and pwm fraction to get
+ * as many uniquely-visible brightness levels as possible. The lowest current
+ * level for any average current is used even though many combinations give
+ * duplicate values. Current (I) values are in mA. */
+static const struct
+{
+    unsigned char md;
+    unsigned char pwm;
+} led_md_pwm_table[] =
+{
+               /* I-level PWM(x/15) I-Avg */
+    { 0,  0 }, /*    0        0      0.0  */
+    { 1,  1 }, /*    3        1      0.2  */
+    { 1,  2 }, /*    3        2      0.4  */
+    { 1,  3 }, /*    3        3      0.6  */ 
+    { 1,  4 }, /*    3        4      0.8  */ 
+    { 1,  5 }, /*    3        5      1.0  */ 
+    { 1,  6 }, /*    3        6      1.2  */ 
+    { 1,  7 }, /*    3        7      1.4  */ 
+    { 1,  8 }, /*    3        8      1.6  */ 
+    { 1,  9 }, /*    3        9      1.8  */ 
+    { 1, 10 }, /*    3       10      2.0  */ 
+    { 1, 11 }, /*    3       11      2.2  */ 
+    { 1, 12 }, /*    3       12      2.4  */ /* default */
+    { 1, 13 }, /*    3       13      2.6  */ 
+    { 1, 14 }, /*    3       14      2.8  */ 
+    { 1, 15 }, /*    3       15      3.0  */ 
+    { 2,  9 }, /*    6        9      3.6  */ 
+    { 2, 10 }, /*    6       10      4.0  */ 
+    { 2, 11 }, /*    6       11      4.4  */ 
+    { 2, 12 }, /*    6       12      4.8  */ 
+    { 2, 13 }, /*    6       13      5.2  */ 
+    { 2, 14 }, /*    6       14      5.6  */ 
+    { 2, 15 }, /*    6       15      6.0  */ 
+    { 3, 11 }, /*    9       11      6.6  */ 
+    { 3, 12 }, /*    9       12      7.2  */ 
+    /* Anything higher is just too much   */
+};
+#endif /* HAVE_BACKLIGHT_BRIGHTNESS */
+
+/* Bits always combined with ramping bits */
+#define MC13783_LED_CONTROL0_BITS \
+    (MC13783_BOOSTEN | MC13783_ABMODE_MONCH_LEDMD1234 | \
+     MC13783_ABREF_400MV)
+
+static struct mutex backlight_mutex;    /* Block brightness change while
+                                         * setting up fading */
+static bool backlight_on_status = true; /* Is on or off? */
+static uint32_t backlight_pwm_bits;     /* Final PWM setting for fade-in */
+
+/* Backlight ramping settings */
+static uint32_t led_ramp_mask = MC13783_LEDMDRAMPDOWN | MC13783_LEDMDRAMPUP;
+
+bool _backlight_init(void)
+{
+    mutex_init(&backlight_mutex);
+
+    /* Set default LED register value */
+    mc13783_write(MC13783_LED_CONTROL0,
+                  MC13783_LED_CONTROL0_BITS | MC13783_LEDEN);
+
+#ifdef HAVE_BACKLIGHT_BRIGHTNESS
+    /* Our PWM and I-Level is different than retailos (but same apparent
+     * brightness), so init to our default. */
+    _backlight_set_brightness(DEFAULT_BRIGHTNESS_SETTING);
+#else
+    /* Use default PWM */
+    backlight_pwm_bits = mc13783_read(MC13783_LED_CONTROL2) & MC13783_LEDMDDC;
+#endif
+
+    return true;
+}
+
+void backlight_set_fade_out(bool value)
+{
+    if (value)
+        led_ramp_mask |= MC13783_LEDMDRAMPDOWN;
+    else
+        led_ramp_mask &= ~MC13783_LEDMDRAMPDOWN;
+}
+
+void backlight_set_fade_in(bool value)
+{
+    if (value)
+        led_ramp_mask |= MC13783_LEDMDRAMPUP;
+    else
+        led_ramp_mask &= ~MC13783_LEDMDRAMPUP;
+}
+
+void _backlight_on(void)
+{
+    static const char regs[2] =
+    {
+        MC13783_LED_CONTROL0,
+        MC13783_LED_CONTROL2
+    };
+
+    uint32_t data[2];
+
+    mutex_lock(&backlight_mutex);
+
+#ifdef HAVE_LCD_ENABLE
+    lcd_enable(true);
+#endif
+
+    /* Set/clear LEDRAMPUP bit, clear LEDRAMPDOWN bit,
+     * Ensure LED supply is on. */
+    data[0] = MC13783_LED_CONTROL0_BITS | MC13783_LEDEN;
+
+    if (!backlight_on_status)
+        data[0] |= led_ramp_mask & MC13783_LEDMDRAMPUP;
+
+    backlight_on_status = true;
+
+    /* Specify final PWM setting */
+    data[1] = mc13783_read(MC13783_LED_CONTROL2);
+
+    if (data[1] != MC13783_DATA_ERROR)
+    {
+        data[1] &= ~MC13783_LEDMDDC;
+        data[1] |= backlight_pwm_bits;
+
+        /* Write regs within 30us of each other (requires single xfer) */
+        mc13783_write_regset(regs, data, 2);
+    }
+
+    mutex_unlock(&backlight_mutex);
+}
+
+void _backlight_off(void)
+{
+    uint32_t ctrl0 = MC13783_LED_CONTROL0_BITS | MC13783_LEDEN;
+
+    mutex_lock(&backlight_mutex);
+
+    if (backlight_on_status)
+        ctrl0 |= led_ramp_mask & MC13783_LEDMDRAMPDOWN;
+
+    backlight_on_status = false;
+
+    /* Set/clear LEDRAMPDOWN bit, clear LEDRAMPUP bit */
+    mc13783_write(MC13783_LED_CONTROL0, ctrl0);
+
+    /* Wait 100us - 500ms */
+    sleep(HZ/100);
+
+    /* Write final PWM setting */
+    mc13783_write_masked(MC13783_LED_CONTROL2,
+                         0 << MC13783_LEDMDDC_POS,
+                         MC13783_LEDMDDC);
+
+    mutex_unlock(&backlight_mutex);
+}
+
+#ifdef HAVE_BACKLIGHT_BRIGHTNESS
+/* Assumes that the backlight has been initialized - parameter should
+ * already be range-checked in public interface. */
+void _backlight_set_brightness(int brightness)
+{
+    uint32_t md;
+
+    mutex_lock(&backlight_mutex);
+
+    md = led_md_pwm_table[brightness].md;
+    backlight_pwm_bits = backlight_on_status ?
+        (led_md_pwm_table[brightness].pwm << MC13783_LEDMDDC_POS) : 0;
+
+    mc13783_write_masked(MC13783_LED_CONTROL2,
+                         (md << MC13783_LEDMD_POS) | backlight_pwm_bits,
+                         MC13783_LEDMD | MC13783_LEDMDDC);
+
+    mutex_unlock(&backlight_mutex);
+}
+#endif /* HAVE_BACKLIGHT_BRIGHTNESS */
+
+#ifdef HAVE_LCD_SLEEP
+/* Turn off LED supply */
+void _backlight_lcd_sleep(void)
+{
+    mutex_lock(&backlight_mutex);
+
+    mc13783_clear(MC13783_LED_CONTROL0, MC13783_LEDEN);
+
+    mutex_unlock(&backlight_mutex);
+}
+#endif