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bus: sunxi-rsb: Implement runtime power management 

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

Signed-off-by: Samuel Holland <samuel@sholland.org>
Acked-by: Maxime Ripard <mripard@kernel.org>
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
This commit is contained in:
Samuel Holland 2021-01-03 05:06:35 -06:00 committed by Chen-Yu Tsai
parent 843107498f
commit 4a0dbc12e6
1 changed files with 44 additions and 0 deletions
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44
drivers/bus/sunxi-rsb.c
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@ -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 @@ err_clk_disable:
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)
};