[src/trunk]: src/sys/dev/pci/voyager add backlight control via sm502 PWM

[macallan <macallan%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/aede04368e37
branches:  trunk
changeset: 770480:aede04368e37
user:      macallan <macallan%NetBSD.org@localhost>
date:      Tue Oct 18 17:59:01 2011 +0000

description:
add backlight control via sm502 PWM

diffstat:

 sys/dev/pci/voyager/voyagerfb.c |  57 +++++++++++++++++++++++++++++++++-------
 1 files changed, 46 insertions(+), 11 deletions(-)

diffs (107 lines):

diff -r 0b4c068cfa63 -r aede04368e37 sys/dev/pci/voyager/voyagerfb.c
--- a/sys/dev/pci/voyager/voyagerfb.c   Tue Oct 18 17:57:40 2011 +0000
+++ b/sys/dev/pci/voyager/voyagerfb.c   Tue Oct 18 17:59:01 2011 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: voyagerfb.c,v 1.6 2011/09/28 02:36:37 macallan Exp $   */
+/*     $NetBSD: voyagerfb.c,v 1.7 2011/10/18 17:59:01 macallan Exp $   */
 
 /*
  * Copyright (c) 2009 Michael Lorenz
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: voyagerfb.c,v 1.6 2011/09/28 02:36:37 macallan Exp $");
+__KERNEL_RCSID(0, "$NetBSD: voyagerfb.c,v 1.7 2011/10/18 17:59:01 macallan Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -158,6 +158,7 @@
        NULL    /* scroll */
 };
 
+static void    voyagerfb_setup_backlight(struct voyagerfb_softc *);
 static void    voyagerfb_brightness_up(device_t);
 static void    voyagerfb_brightness_down(device_t);
 /* set backlight level */
@@ -273,13 +274,7 @@
 
        /* backlight control */
        sc->sc_gpio_cookie = device_private(parent);
-       voyager_write_gpio(sc->sc_gpio_cookie, 0xffffffff, GPIO_BACKLIGHT);
-       sc->sc_bl_on = 1;
-       sc->sc_bl_level = 255;
-       pmf_event_register(sc->sc_dev, PMFE_DISPLAY_BRIGHTNESS_UP,
-           voyagerfb_brightness_up, TRUE);
-       pmf_event_register(sc->sc_dev, PMFE_DISPLAY_BRIGHTNESS_DOWN,
-           voyagerfb_brightness_down, TRUE);
+       voyagerfb_setup_backlight(sc);
 
        /* init engine here */
        voyagerfb_init(sc);
@@ -971,6 +966,21 @@
 
 /* backlight control */
 static void
+voyagerfb_setup_backlight(struct voyagerfb_softc *sc)
+{
+       /* switch the pin to gpio mode if it isn't already */
+       voyager_control_gpio(sc->sc_gpio_cookie, ~GPIO_BACKLIGHT, 0);
+       /* turn it on */
+       voyager_write_gpio(sc->sc_gpio_cookie, 0xffffffff, GPIO_BACKLIGHT);
+       sc->sc_bl_on = 1;
+       sc->sc_bl_level = 255;
+       pmf_event_register(sc->sc_dev, PMFE_DISPLAY_BRIGHTNESS_UP,
+           voyagerfb_brightness_up, TRUE);
+       pmf_event_register(sc->sc_dev, PMFE_DISPLAY_BRIGHTNESS_DOWN,
+           voyagerfb_brightness_down, TRUE);
+}
+
+static void
 voyagerfb_set_backlight(struct voyagerfb_softc *sc, int level)
 {
 
@@ -988,8 +998,25 @@
        sc->sc_bl_level = level;
        if (sc->sc_bl_on == 0)
                sc->sc_bl_on = 1;
-       level = 255 - level;
        /* and here we would actually muck with the hardware */
+       if ((level == 0) || (level == 255)) {
+               /* in these cases bypass the PWM and use the gpio */
+               voyager_control_gpio(sc->sc_gpio_cookie, ~GPIO_BACKLIGHT, 0);
+               if (level == 0) {
+                       voyager_write_gpio(sc->sc_gpio_cookie, ~GPIO_BACKLIGHT, 0);
+               } else {
+                       voyager_write_gpio(sc->sc_gpio_cookie, 0xffffffff, GPIO_BACKLIGHT);
+               }
+       } else {
+               uint32_t pwm;
+
+               pwm = voyager_set_pwm(20000, level * 1000 / 256);
+               pwm |= SM502_PWM_ENABLE;
+               bus_space_write_4(sc->sc_memt, sc->sc_regh, SM502_PWM0, pwm);
+
+               /* let the PWM take over */
+               voyager_control_gpio(sc->sc_gpio_cookie, 0xffffffff, GPIO_BACKLIGHT);
+       }
 }
 
 static void
@@ -999,7 +1026,15 @@
        if (on == sc->sc_bl_on)
                return;
        sc->sc_bl_on = on;
-       voyager_write_gpio(sc->sc_gpio_cookie, ~GPIO_BACKLIGHT, on ? GPIO_BACKLIGHT : 0);
+       if (on) {
+               int level = sc->sc_bl_level;
+
+               sc->sc_bl_level = -1;
+               voyagerfb_set_backlight(sc, level);
+       } else {
+               voyager_control_gpio(sc->sc_gpio_cookie, ~GPIO_BACKLIGHT, 0);
+               voyager_write_gpio(sc->sc_gpio_cookie, ~GPIO_BACKLIGHT, 0);
+       }
 }