ARM: tegra: stingray: Turn on the lvds bridge chip during early resume

Adds a platform driver that enables the lvds bridge chip regulator
during early resume and then disables it 1 second later.  This prevents
waiting for 200 msec during late resume for the bridge chip to turn on.

Change-Id: I112d397a83bad8998d28d9b2e97dbb75aa9f8e95
Signed-off-by: Colin Cross <ccross@android.com>

diff --git a/arch/arm/mach-tegra/board-stingray-panel.c b/arch/arm/mach-tegra/board-stingray-panel.c
index 2c4f57c6f4b9ff6d92201fa6cf2a27e19f5fe865..09f929c70f2f92c0e6ccf3126f7fe2be79d9a482 100644 (file)
--- a/arch/arm/mach-tegra/board-stingray-panel.c
+++ b/arch/arm/mach-tegra/board-stingray-panel.c
@@ -208,6 +208,73 @@ static int stingray_panel_disable(void)
        return 0;
 }
 
+static void stingray_panel_early_reg_disable(struct work_struct *work)
+{
+       stingray_panel_disable();
+}
+
+static DECLARE_DELAYED_WORK(stingray_panel_early_reg_disable_work,
+       stingray_panel_early_reg_disable);
+
+static void stingray_panel_early_reg_enable(struct work_struct *work)
+{
+       stingray_panel_enable();
+
+       /*
+        * Once the panel is powered up, set it to power down in 1 second.
+        * If no other driver calls regulator_enable on stingray_panel_regulator
+        * before 1 second has elapsed, the bridge chip will power down.
+        */
+       schedule_delayed_work(&stingray_panel_early_reg_disable_work, HZ);
+}
+
+static DECLARE_WORK(stingray_panel_early_reg_enable_work,
+       stingray_panel_early_reg_enable);
+
+static int stingray_panel_early_reg_resume_noirq(struct device *dev)
+{
+       /* Start the bridge chip powering up during early resume */
+       schedule_work(&stingray_panel_early_reg_enable_work);
+
+       return 0;
+}
+
+static int stingray_panel_early_reg_suspend(struct device *dev)
+{
+       cancel_work_sync(&stingray_panel_early_reg_enable_work);
+
+       /*
+        * If the delayed disable work was pending when it was cancelled,
+        * do the disable immediately.
+        */
+       if (cancel_delayed_work_sync(&stingray_panel_early_reg_disable_work))
+               stingray_panel_disable();
+
+       return 0;
+}
+
+static struct dev_pm_ops stingray_panel_early_reg_pm_ops = {
+       .resume_noirq = stingray_panel_early_reg_resume_noirq,
+       .suspend = stingray_panel_early_reg_suspend,
+};
+
+/*
+ * This driver uses a resume_noirq handler to start the bridge chip powering up
+ * as soon as possible during resume to avoid waiting for 200 ms after all the
+ * other resume handlers have finished.
+ */
+static struct platform_driver stingray_panel_early_reg_driver = {
+       .driver = {
+               .name   = "stingray-panel-early-reg",
+               .owner  = THIS_MODULE,
+               .pm = &stingray_panel_early_reg_pm_ops,
+       }
+};
+
+static struct platform_device stingray_panel_early_reg_device = {
+       .name = "stingray-panel-early-reg",
+};
+
 static struct tegra_dc_out stingray_disp1_out = {
        .type = TEGRA_DC_OUT_RGB,
 
@@ -394,6 +461,9 @@ int __init stingray_panel_init(void)
 
        platform_device_register(&stingray_panel_reg_device);
 
+       platform_driver_register(&stingray_panel_early_reg_driver);
+       platform_device_register(&stingray_panel_early_reg_device);
+
        stingray_hdmi_init();
 
        stingray_csi_reg = regulator_get(NULL, "vcsi");