gpio/omap: force restore if context loss is not detectable

When booting with device-tree the function pointer for detecting context
loss is not populated. Ideally, the pm_runtime framework should be
enhanced to allow a means for reporting context/state loss and we could
avoid populating such function pointers altogether. In the interim until
a generic non-device specific solution is in place, force a restore of
the gpio bank when enabling the gpio controller.

Adds a new device-tree property for the OMAP GPIO controller to indicate
if the GPIO controller is located in a power-domain that never loses
power and hence will always maintain its logic state.

Signed-off-by: Jon Hunter <jon-hunter@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Reviewed-by: Kevin Hilman <khilman@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

1 files changed, 17 insertions, 8 deletions

diff --git a/drivers/gpio/gpio-omap.c b/drivers/gpio/gpio-omap.c
index f46b600e5e56..bb1e54f168b4 100644
--- a/drivers/gpio/gpio-omap.c
+++ b/drivers/gpio/gpio-omap.c
@@ -1120,11 +1120,17 @@ static int omap_gpio_probe(struct platform_device *pdev)
         bank->width = pdata->bank_width;
         bank->is_mpuio = pdata->is_mpuio;
         bank->non_wakeup_gpios = pdata->non_wakeup_gpios;
-        bank->loses_context = pdata->loses_context;
         bank->regs = pdata->regs;
 #ifdef CONFIG_OF_GPIO
         bank->chip.of_node = of_node_get(node);
 #endif
+        if (node) {
+                if (!of_property_read_bool(node, "ti,gpio-always-on"))
+                        bank->loses_context = true;
+        } else {
+                bank->loses_context = pdata->loses_context;
+        }
+
 
         bank->domain = irq_domain_add_linear(node, bank->width,
                                              &irq_domain_simple_ops, NULL);
@@ -1258,9 +1264,9 @@ static int omap_gpio_runtime_resume(struct device *dev)
 {
         struct platform_device *pdev = to_platform_device(dev);
         struct gpio_bank *bank = platform_get_drvdata(pdev);
-        int context_lost_cnt_after;
         u32 l = 0, gen, gen0, gen1;
         unsigned long flags;
+        int c;
 
         spin_lock_irqsave(&bank->lock, flags);
         _gpio_dbck_enable(bank);
@@ -1276,14 +1282,17 @@ static int omap_gpio_runtime_resume(struct device *dev)
         __raw_writel(bank->context.risingdetect,
                      bank->base + bank->regs->risingdetect);
 
-        if (bank->get_context_loss_count) {
-                context_lost_cnt_after =
-                        bank->get_context_loss_count(bank->dev);
-                if (context_lost_cnt_after != bank->context_loss_count) {
+        if (bank->loses_context) {
+                if (!bank->get_context_loss_count) {
                         omap_gpio_restore_context(bank);
                 } else {
-                        spin_unlock_irqrestore(&bank->lock, flags);
-                        return 0;
+                        c = bank->get_context_loss_count(bank->dev);
+                        if (c != bank->context_loss_count) {
+                                omap_gpio_restore_context(bank);
+                        } else {
+                                spin_unlock_irqrestore(&bank->lock, flags);
+                                return 0;
+                        }
                 }
         }