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authorAndrew Chew <achew@nvidia.com>2014-02-10 16:44:18 -0800
committerMarc Jones <marc.jones@se-eng.com>2014-11-12 20:16:43 +0100
commit7f0cb159994985dffe76ff034aae5a844386b447 (patch)
treebaa2a38b2b123df06562340ff643191ab771e2bc /src
parent372a5bbd66cb247abed173685d4a6fe0a3188246 (diff)
downloadcoreboot-7f0cb159994985dffe76ff034aae5a844386b447.tar.xz
tegra124: Program PWM1 to drive panel backlight
Repurpose config->pwm to mean the particular PWM device (we use PWM1 on nyan), and add code to program the PWM device. BUG=none TEST=emerge-nyan chromeos-coreboot-nyan, regenerate bootimage, and boot. See that the backlight comes up in the bootloader, and brightness can be adjusted via pwm_bl driver in the kernel. Original-Change-Id: I2db047e5ef23c0e8fb66dd05ad6339d60918d493 Original-Signed-off-by: Andrew Chew <achew@nvidia.com> Original-Reviewed-on: https://chromium-review.googlesource.com/185772 Original-Reviewed-by: Andrew Bresticker <abrestic@chromium.org> (cherry picked from commit 0dee98dd0c8510ecd630b5c6cb9ea49724dc8b55) Signed-off-by: Marc Jones <marc.jones@se-eng.com> Change-Id: Ie53610f3afa30b2d8f484685fb0e8c0b12cd8241 Reviewed-on: http://review.coreboot.org/7402 Tested-by: build bot (Jenkins) Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Diffstat (limited to 'src')
-rw-r--r--src/mainboard/google/nyan/devicetree.cb2
-rw-r--r--src/mainboard/google/nyan_big/devicetree.cb2
-rw-r--r--src/soc/nvidia/tegra124/display.c16
3 files changed, 13 insertions, 7 deletions
diff --git a/src/mainboard/google/nyan/devicetree.cb b/src/mainboard/google/nyan/devicetree.cb
index 58945568e9..5ae86913d1 100644
--- a/src/mainboard/google/nyan/devicetree.cb
+++ b/src/mainboard/google/nyan/devicetree.cb
@@ -38,7 +38,7 @@ chip soc/nvidia/tegra124
register "lvds_shutdown_gpio" = "0"
register "backlight_vdd_gpio" = "GPIO(P2)"
register "panel_vdd_gpio" = "0"
- register "pwm" = "GPIO(H1)"
+ register "pwm" = "1"
# taken from u-boot; these look wrong however.
register "vdd_delay" = "400"
diff --git a/src/mainboard/google/nyan_big/devicetree.cb b/src/mainboard/google/nyan_big/devicetree.cb
index cb55b72b93..9541ce9c9d 100644
--- a/src/mainboard/google/nyan_big/devicetree.cb
+++ b/src/mainboard/google/nyan_big/devicetree.cb
@@ -38,7 +38,7 @@ chip soc/nvidia/tegra124
register "lvds_shutdown_gpio" = "0"
register "backlight_vdd_gpio" = "GPIO(P2)"
register "panel_vdd_gpio" = "0"
- register "pwm" = "GPIO(H1)"
+ register "pwm" = "1"
# taken from u-boot; these look wrong however.
register "vdd_delay" = "400"
diff --git a/src/soc/nvidia/tegra124/display.c b/src/soc/nvidia/tegra124/display.c
index 2fbec50cf8..8c4e8232dd 100644
--- a/src/soc/nvidia/tegra124/display.c
+++ b/src/soc/nvidia/tegra124/display.c
@@ -33,6 +33,7 @@
#include <edid.h>
#include <soc/clock.h>
#include <soc/nvidia/tegra/dc.h>
+#include <soc/nvidia/tegra/pwm.h>
#include <soc/nvidia/tegra124/sdram.h>
#include "chip.h"
#include <soc/display.h>
@@ -240,6 +241,7 @@ void display_startup(device_t dev)
int i;
struct soc_nvidia_tegra124_config *config = dev->chip_info;
struct display_controller *dc = (void *)config->display_controller;
+ struct pwm_controller *pwm = (void *)TEGRA_PWM_BASE;
struct disp_ctl_win window;
/* should probably just make it all MiB ... in future */
@@ -270,11 +272,15 @@ void display_startup(device_t dev)
__func__, config->backlight_en_gpio, 1);
}
- if (config->pwm){
- gpio_output(config->pwm, 1);
- printk(BIOS_SPEW,"%s: pwm setting gpio %08x to %d\n",
- __func__, config->pwm, 1);
- }
+ /* Set up Tegra PWM n (where n is specified in config->pwm) to drive the
+ * panel backlight.
+ */
+ printk(BIOS_SPEW, "%s: enable panel backlight pwm\n", __func__);
+ WRITEL(((1 << NV_PWM_CSR_ENABLE_SHIFT) |
+ (220 << NV_PWM_CSR_PULSE_WIDTH_SHIFT) | /* 220/256 */
+ 0x02e), /* frequency divider */
+ &pwm->pwm[config->pwm].csr);
+
printk(BIOS_SPEW,
"%s: xres %d yres %d framebuffer_bits_per_pixel %d\n",
__func__,