Unverified Commit 96ed3ecd authored by Radu Pirea's avatar Radu Pirea Committed by Mark Brown
Browse files

spi: at91-usart: add power management support 



This patch implements power management callback function for USART as
SPI driver.

Signed-off-by: default avatarRadu Pirea <radu_nicolae.pirea@upb.ro>
Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent 1d2319ef

drivers/spi/spi-at91-usart.c

+61 −0
Original line number Diff line number Diff line
@@ -13,6 +13,7 @@ 
#include <linux/module.h>

#include <linux/of_gpio.h>

#include <linux/platform_device.h>

#include <linux/pm_runtime.h>



#include <linux/spi/spi.h>
@@ -399,6 +400,59 @@ static int at91_usart_spi_probe(struct platform_device *pdev) 
	return ret;

}



__maybe_unused static int at91_usart_spi_runtime_suspend(struct device *dev)

{

	struct spi_controller *ctlr = dev_get_drvdata(dev);

	struct at91_usart_spi *aus = spi_master_get_devdata(ctlr);



	clk_disable_unprepare(aus->clk);

	pinctrl_pm_select_sleep_state(dev);



	return 0;

}



__maybe_unused static int at91_usart_spi_runtime_resume(struct device *dev)

{

	struct spi_controller *ctrl = dev_get_drvdata(dev);

	struct at91_usart_spi *aus = spi_master_get_devdata(ctrl);



	pinctrl_pm_select_default_state(dev);



	return clk_prepare_enable(aus->clk);

}



__maybe_unused static int at91_usart_spi_suspend(struct device *dev)

{

	struct spi_controller *ctrl = dev_get_drvdata(dev);

	int ret;



	ret = spi_controller_suspend(ctrl);

	if (ret)

		return ret;



	if (!pm_runtime_suspended(dev))

		at91_usart_spi_runtime_suspend(dev);



	return 0;

}



__maybe_unused static int at91_usart_spi_resume(struct device *dev)

{

	struct spi_controller *ctrl = dev_get_drvdata(dev);

	struct at91_usart_spi *aus = spi_master_get_devdata(ctrl);

	int ret;



	if (!pm_runtime_suspended(dev)) {

		ret = at91_usart_spi_runtime_resume(dev);

		if (ret)

			return ret;

	}



	at91_usart_spi_init(aus);



	return spi_controller_resume(ctrl);

}



static int at91_usart_spi_remove(struct platform_device *pdev)

{

	struct spi_controller *ctlr = platform_get_drvdata(pdev);
@@ -409,6 +463,12 @@ static int at91_usart_spi_remove(struct platform_device *pdev) 
	return 0;

}



static const struct dev_pm_ops at91_usart_spi_pm_ops = {

	SET_SYSTEM_SLEEP_PM_OPS(at91_usart_spi_suspend, at91_usart_spi_resume)

	SET_RUNTIME_PM_OPS(at91_usart_spi_runtime_suspend,

			   at91_usart_spi_runtime_resume, NULL)

};



static const struct of_device_id at91_usart_spi_dt_ids[] = {

	{ .compatible = "microchip,at91sam9g45-usart-spi"},

	{ /* sentinel */}
@@ -419,6 +479,7 @@ MODULE_DEVICE_TABLE(of, at91_usart_spi_dt_ids); 
static struct platform_driver at91_usart_spi_driver = {

	.driver = {

		.name = "at91_usart_spi",

		.pm = &at91_usart_spi_pm_ops,

	},

	.probe = at91_usart_spi_probe,

	.remove = at91_usart_spi_remove,