Commit 4a0dbc12 authored by Samuel Holland's avatar Samuel Holland Committed by Chen-Yu Tsai
Browse files

bus: sunxi-rsb: Implement runtime power management 



Gate the clock to save power while the controller is idle.

Signed-off-by: default avatarSamuel Holland <samuel@sholland.org>
Acked-by: default avatarMaxime Ripard <mripard@kernel.org>
Signed-off-by: default avatarChen-Yu Tsai <wens@csie.org>
parent 84310749

drivers/bus/sunxi-rsb.c

+44 −0
Original line number Diff line number Diff line
@@ -46,6 +46,7 @@ 
#include <linux/of_platform.h>

#include <linux/platform_device.h>

#include <linux/pm.h>

#include <linux/pm_runtime.h>

#include <linux/regmap.h>

#include <linux/reset.h>

#include <linux/slab.h>
@@ -337,6 +338,10 @@ static int sunxi_rsb_read(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr, 
		return -EINVAL;

	}



	ret = pm_runtime_resume_and_get(rsb->dev);

	if (ret)

		return ret;



	mutex_lock(&rsb->lock);



	writel(addr, rsb->regs + RSB_ADDR);
@@ -352,6 +357,9 @@ static int sunxi_rsb_read(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr, 
unlock:

	mutex_unlock(&rsb->lock);



	pm_runtime_mark_last_busy(rsb->dev);

	pm_runtime_put_autosuspend(rsb->dev);



	return ret;

}
@@ -379,6 +387,10 @@ static int sunxi_rsb_write(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr, 
		return -EINVAL;

	}



	ret = pm_runtime_resume_and_get(rsb->dev);

	if (ret)

		return ret;



	mutex_lock(&rsb->lock);



	writel(addr, rsb->regs + RSB_ADDR);
@@ -389,6 +401,9 @@ static int sunxi_rsb_write(struct sunxi_rsb *rsb, u8 rtaddr, u8 addr, 


	mutex_unlock(&rsb->lock);



	pm_runtime_mark_last_busy(rsb->dev);

	pm_runtime_put_autosuspend(rsb->dev);



	return ret;

}
@@ -672,10 +687,29 @@ static int sunxi_rsb_hw_init(struct sunxi_rsb *rsb) 


static void sunxi_rsb_hw_exit(struct sunxi_rsb *rsb)

{

	/* Keep the clock and PM reference counts consistent. */

	if (pm_runtime_status_suspended(rsb->dev))

		pm_runtime_resume(rsb->dev);

	reset_control_assert(rsb->rstc);

	clk_disable_unprepare(rsb->clk);

}



static int __maybe_unused sunxi_rsb_runtime_suspend(struct device *dev)

{

	struct sunxi_rsb *rsb = dev_get_drvdata(dev);



	clk_disable_unprepare(rsb->clk);



	return 0;

}



static int __maybe_unused sunxi_rsb_runtime_resume(struct device *dev)

{

	struct sunxi_rsb *rsb = dev_get_drvdata(dev);



	return clk_prepare_enable(rsb->clk);

}



static int __maybe_unused sunxi_rsb_suspend(struct device *dev)

{

	struct sunxi_rsb *rsb = dev_get_drvdata(dev);
@@ -758,6 +792,12 @@ static int sunxi_rsb_probe(struct platform_device *pdev) 
	if (ret)

		dev_warn(dev, "Initialize device mode failed: %d\n", ret);



	pm_suspend_ignore_children(dev, true);

	pm_runtime_set_active(dev);

	pm_runtime_set_autosuspend_delay(dev, MSEC_PER_SEC);

	pm_runtime_use_autosuspend(dev);

	pm_runtime_enable(dev);



	of_rsb_register_devices(rsb);



	return 0;
@@ -768,6 +808,7 @@ static int sunxi_rsb_remove(struct platform_device *pdev) 
	struct sunxi_rsb *rsb = platform_get_drvdata(pdev);



	device_for_each_child(rsb->dev, NULL, sunxi_rsb_remove_devices);

	pm_runtime_disable(&pdev->dev);

	sunxi_rsb_hw_exit(rsb);



	return 0;
@@ -777,10 +818,13 @@ static void sunxi_rsb_shutdown(struct platform_device *pdev) 
{

	struct sunxi_rsb *rsb = platform_get_drvdata(pdev);



	pm_runtime_disable(&pdev->dev);

	sunxi_rsb_hw_exit(rsb);

}



static const struct dev_pm_ops sunxi_rsb_dev_pm_ops = {

	SET_RUNTIME_PM_OPS(sunxi_rsb_runtime_suspend,

			   sunxi_rsb_runtime_resume, NULL)

	SET_NOIRQ_SYSTEM_SLEEP_PM_OPS(sunxi_rsb_suspend, sunxi_rsb_resume)

};