From 4a0dbc12e61823ece7172df953c3333c8f5f9222 Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Sun, 3 Jan 2021 05:06:35 -0600 Subject: bus: sunxi-rsb: Implement runtime power management Gate the clock to save power while the controller is idle. Signed-off-by: Samuel Holland Acked-by: Maxime Ripard Signed-off-by: Chen-Yu Tsai --- drivers/bus/sunxi-rsb.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) (limited to 'drivers/bus/sunxi-rsb.c') diff --git a/drivers/bus/sunxi-rsb.c b/drivers/bus/sunxi-rsb.c index efd222f36cdc..ba5100dfc413 100644 --- a/drivers/bus/sunxi-rsb.c +++ b/drivers/bus/sunxi-rsb.c @@ -46,6 +46,7 @@ #include #include #include +#include #include #include #include @@ -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) }; -- cgit v1.2.3