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

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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>
This commit is contained in:
Jon Hunter 2013-04-04 15:16:15 -05:00 committed by Linus Walleij
parent 3513cdeccc
commit a2797beadf
2 changed files with 22 additions and 10 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

7
Documentation/devicetree/bindings/gpio/gpio-omap.txt
View file

@ -20,8 +20,11 @@ Required properties:
8 = active low level-sensitive. 8 = active low level-sensitive.
OMAP specific properties: OMAP specific properties:
- ti,hwmods: Name of the hwmod associated to the GPIO: - ti,hwmods: Name of the hwmod associated to the GPIO:
"gpio<X>", <X> being the 1-based instance number from the HW spec "gpio<X>", <X> being the 1-based instance number
from the HW spec.
- ti,gpio-always-on: Indicates if a GPIO bank is always powered and
so will never lose its logic state.
Example: Example:

25
drivers/gpio/gpio-omap.c
View file

@ -1120,11 +1120,17 @@ static int omap_gpio_probe(struct platform_device *pdev)
bank->width = pdata->bank_width; bank->width = pdata->bank_width;
bank->is_mpuio = pdata->is_mpuio; bank->is_mpuio = pdata->is_mpuio;
bank->non_wakeup_gpios = pdata->non_wakeup_gpios; bank->non_wakeup_gpios = pdata->non_wakeup_gpios;
bank->loses_context = pdata->loses_context;
bank->regs = pdata->regs; bank->regs = pdata->regs;
#ifdef CONFIG_OF_GPIO #ifdef CONFIG_OF_GPIO
bank->chip.of_node = of_node_get(node); bank->chip.of_node = of_node_get(node);
#endif #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, bank->domain = irq_domain_add_linear(node, bank->width,
&irq_domain_simple_ops, NULL); &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 platform_device *pdev = to_platform_device(dev);
struct gpio_bank *bank = platform_get_drvdata(pdev); struct gpio_bank *bank = platform_get_drvdata(pdev);
int context_lost_cnt_after;
u32 l = 0, gen, gen0, gen1; u32 l = 0, gen, gen0, gen1;
unsigned long flags; unsigned long flags;
int c;
spin_lock_irqsave(&bank->lock, flags); spin_lock_irqsave(&bank->lock, flags);
_gpio_dbck_enable(bank); _gpio_dbck_enable(bank);
@ -1276,14 +1282,17 @@ static int omap_gpio_runtime_resume(struct device *dev)
__raw_writel(bank->context.risingdetect, __raw_writel(bank->context.risingdetect,
bank->base + bank->regs->risingdetect); bank->base + bank->regs->risingdetect);
if (bank->get_context_loss_count) { if (bank->loses_context) {
context_lost_cnt_after = if (!bank->get_context_loss_count) {
bank->get_context_loss_count(bank->dev);
if (context_lost_cnt_after != bank->context_loss_count) {
omap_gpio_restore_context(bank); omap_gpio_restore_context(bank);
} else { } else {
spin_unlock_irqrestore(&bank->lock, flags); c = bank->get_context_loss_count(bank->dev);
return 0; if (c != bank->context_loss_count) {
omap_gpio_restore_context(bank);
} else {
spin_unlock_irqrestore(&bank->lock, flags);
return 0;
}
} }
} }