[LINUX PATCH V3 7/9] gpio: gpio-xilinx: Add support for suspend and resume

From: Srinivas Neeli
Date: Thu Nov 12 2020 - 12:13:42 EST


Add support for suspend and resume, pm runtime suspend and resume.
Added free and request calls.

Signed-off-by: Srinivas Neeli <srinivas.neeli@xxxxxxxxxx>
---
Changes in V3:
-Created new patch for suspend and resume.
---
drivers/gpio/gpio-xilinx.c | 89 ++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 87 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-xilinx.c b/drivers/gpio/gpio-xilinx.c
index 9abef56eca32..48f2a6c894f5 100644
--- a/drivers/gpio/gpio-xilinx.c
+++ b/drivers/gpio/gpio-xilinx.c
@@ -17,6 +17,7 @@
#include <linux/of_device.h>
#include <linux/of_gpio.h>
#include <linux/of_platform.h>
+#include <linux/pm_runtime.h>
#include <linux/slab.h>

/* Register Offset Definitions */
@@ -275,6 +276,39 @@ static void xgpio_save_regs(struct xgpio_instance *chip)
chip->gpio_dir[1]);
}

+static int xgpio_request(struct gpio_chip *chip, unsigned int offset)
+{
+ int ret;
+
+ ret = pm_runtime_get_sync(chip->parent);
+ /*
+ * If the device is already active pm_runtime_get() will return 1 on
+ * success, but gpio_request still needs to return 0.
+ */
+ return ret < 0 ? ret : 0;
+}
+
+static void xgpio_free(struct gpio_chip *chip, unsigned int offset)
+{
+ pm_runtime_put(chip->parent);
+}
+
+static int __maybe_unused xgpio_suspend(struct device *dev)
+{
+ struct xgpio_instance *gpio = dev_get_drvdata(dev);
+ struct irq_data *data = irq_get_irq_data(gpio->irq);
+
+ if (!data) {
+ dev_err(dev, "irq_get_irq_data() failed\n");
+ return -EINVAL;
+ }
+
+ if (!irqd_is_wakeup_set(data))
+ return pm_runtime_force_suspend(dev);
+
+ return 0;
+}
+
/**
* xgpio_irq_ack - Acknowledge a child GPIO interrupt.
* @irq_data: per IRQ and chip data passed down to chip functions
@@ -285,6 +319,46 @@ static void xgpio_irq_ack(struct irq_data *irq_data)
{
}

+static int __maybe_unused xgpio_resume(struct device *dev)
+{
+ struct xgpio_instance *gpio = dev_get_drvdata(dev);
+ struct irq_data *data = irq_get_irq_data(gpio->irq);
+
+ if (!data) {
+ dev_err(dev, "irq_get_irq_data() failed\n");
+ return -EINVAL;
+ }
+
+ if (!irqd_is_wakeup_set(data))
+ return pm_runtime_force_resume(dev);
+
+ return 0;
+}
+
+static int __maybe_unused xgpio_runtime_suspend(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct xgpio_instance *gpio = platform_get_drvdata(pdev);
+
+ clk_disable(gpio->clk);
+
+ return 0;
+}
+
+static int __maybe_unused xgpio_runtime_resume(struct device *dev)
+{
+ struct platform_device *pdev = to_platform_device(dev);
+ struct xgpio_instance *gpio = platform_get_drvdata(pdev);
+
+ return clk_enable(gpio->clk);
+}
+
+static const struct dev_pm_ops xgpio_dev_pm_ops = {
+ SET_SYSTEM_SLEEP_PM_OPS(xgpio_suspend, xgpio_resume)
+ SET_RUNTIME_PM_OPS(xgpio_runtime_suspend,
+ xgpio_runtime_resume, NULL)
+};
+
/**
* xgpio_irq_mask - Write the specified signal of the GPIO device.
* @irq_data: per IRQ and chip data passed down to chip functions
@@ -544,6 +618,8 @@ static int xgpio_probe(struct platform_device *pdev)
chip->gc.of_gpio_n_cells = cells;
chip->gc.get = xgpio_get;
chip->gc.set = xgpio_set;
+ chip->gc.request = xgpio_request;
+ chip->gc.free = xgpio_free;
chip->gc.set_multiple = xgpio_set_multiple;

chip->gc.label = dev_name(&pdev->dev);
@@ -566,6 +642,10 @@ static int xgpio_probe(struct platform_device *pdev)
dev_err(&pdev->dev, "Failed to prepare clk\n");
return status;
}
+ pm_runtime_enable(&pdev->dev);
+ status = pm_runtime_get_sync(&pdev->dev);
+ if (status < 0)
+ goto err_unprepare_clk;

xgpio_save_regs(chip);

@@ -590,7 +670,7 @@ static int xgpio_probe(struct platform_device *pdev)
GFP_KERNEL);
if (!girq->parents) {
status = -ENOMEM;
- goto err_unprepare_clk;
+ goto err_pm_put;
}
girq->parents[0] = chip->irq;
girq->default_type = IRQ_TYPE_NONE;
@@ -600,12 +680,16 @@ static int xgpio_probe(struct platform_device *pdev)
status = devm_gpiochip_add_data(&pdev->dev, &chip->gc, chip);
if (status) {
dev_err(&pdev->dev, "failed to add GPIO chip\n");
- goto err_unprepare_clk;
+ goto err_pm_put;
}

+ pm_runtime_put(&pdev->dev);
return 0;

+err_pm_put:
+ pm_runtime_put_sync(&pdev->dev);
err_unprepare_clk:
+ pm_runtime_disable(&pdev->dev);
clk_disable_unprepare(chip->clk);
return status;
}
@@ -623,6 +707,7 @@ static struct platform_driver xgpio_plat_driver = {
.driver = {
.name = "gpio-xilinx",
.of_match_table = xgpio_of_match,
+ .pm = &xgpio_dev_pm_ops,
},
};

--
2.7.4