gpio: davinci: Add support for system suspend/resume PM

Add support for system suspend/resume PM hooks, save the
register context of all the required gpio registers on suspend
and restore context on the resume.

Signed-off-by: Devarsh Thakkar <devarsht@ti.com>
Signed-off-by: Aswath Govindraju <a-govindraju@ti.com>
Signed-off-by: Bartosz Golaszewski <brgl@bgdev.pl>
This commit is contained in:
Devarsh Thakkar 2022-06-13 11:13:10 +05:30 committed by Bartosz Golaszewski
parent df08a6fc0d
commit 0651a73092

View File

@ -22,6 +22,7 @@
#include <linux/platform_data/gpio-davinci.h>
#include <linux/irqchip/chained_irq.h>
#include <linux/spinlock.h>
#include <linux/pm_runtime.h>
#include <asm-generic/gpio.h>
@ -62,6 +63,8 @@ struct davinci_gpio_controller {
void __iomem *regs[MAX_REGS_BANKS];
int gpio_unbanked;
int irqs[MAX_INT_PER_BANK];
struct davinci_gpio_regs context[MAX_REGS_BANKS];
u32 binten_context;
};
static inline u32 __gpio_mask(unsigned gpio)
@ -622,6 +625,85 @@ done:
return 0;
}
static void davinci_gpio_save_context(struct davinci_gpio_controller *chips,
u32 nbank)
{
struct davinci_gpio_regs __iomem *g;
struct davinci_gpio_regs *context;
u32 bank;
void __iomem *base;
base = chips->regs[0] - offset_array[0];
chips->binten_context = readl_relaxed(base + BINTEN);
for (bank = 0; bank < nbank; bank++) {
g = chips->regs[bank];
context = &chips->context[bank];
context->dir = readl_relaxed(&g->dir);
context->set_data = readl_relaxed(&g->set_data);
context->set_rising = readl_relaxed(&g->set_rising);
context->set_falling = readl_relaxed(&g->set_falling);
}
/* Clear Bank interrupt enable bit */
writel_relaxed(0, base + BINTEN);
/* Clear all interrupt status registers */
writel_relaxed(GENMASK(31, 0), &g->intstat);
}
static void davinci_gpio_restore_context(struct davinci_gpio_controller *chips,
u32 nbank)
{
struct davinci_gpio_regs __iomem *g;
struct davinci_gpio_regs *context;
u32 bank;
void __iomem *base;
base = chips->regs[0] - offset_array[0];
if (readl_relaxed(base + BINTEN) != chips->binten_context)
writel_relaxed(chips->binten_context, base + BINTEN);
for (bank = 0; bank < nbank; bank++) {
g = chips->regs[bank];
context = &chips->context[bank];
if (readl_relaxed(&g->dir) != context->dir)
writel_relaxed(context->dir, &g->dir);
if (readl_relaxed(&g->set_data) != context->set_data)
writel_relaxed(context->set_data, &g->set_data);
if (readl_relaxed(&g->set_rising) != context->set_rising)
writel_relaxed(context->set_rising, &g->set_rising);
if (readl_relaxed(&g->set_falling) != context->set_falling)
writel_relaxed(context->set_falling, &g->set_falling);
}
}
static int davinci_gpio_suspend(struct device *dev)
{
struct davinci_gpio_controller *chips = dev_get_drvdata(dev);
struct davinci_gpio_platform_data *pdata = dev_get_platdata(dev);
u32 nbank = DIV_ROUND_UP(pdata->ngpio, 32);
davinci_gpio_save_context(chips, nbank);
return 0;
}
static int davinci_gpio_resume(struct device *dev)
{
struct davinci_gpio_controller *chips = dev_get_drvdata(dev);
struct davinci_gpio_platform_data *pdata = dev_get_platdata(dev);
u32 nbank = DIV_ROUND_UP(pdata->ngpio, 32);
davinci_gpio_restore_context(chips, nbank);
return 0;
}
DEFINE_SIMPLE_DEV_PM_OPS(davinci_gpio_dev_pm_ops, davinci_gpio_suspend,
davinci_gpio_resume);
static const struct of_device_id davinci_gpio_ids[] = {
{ .compatible = "ti,keystone-gpio", keystone_gpio_get_irq_chip},
{ .compatible = "ti,am654-gpio", keystone_gpio_get_irq_chip},
@ -634,6 +716,7 @@ static struct platform_driver davinci_gpio_driver = {
.probe = davinci_gpio_probe,
.driver = {
.name = "davinci_gpio",
.pm = pm_sleep_ptr(&davinci_gpio_dev_pm_ops),
.of_match_table = of_match_ptr(davinci_gpio_ids),
},
};