diff options
Diffstat (limited to 'drivers/amba/bus.c')
| -rw-r--r-- | drivers/amba/bus.c | 68 |
1 files changed, 64 insertions, 4 deletions
diff --git a/drivers/amba/bus.c b/drivers/amba/bus.c index d74926e0939e..bd230e801131 100644 --- a/drivers/amba/bus.c +++ b/drivers/amba/bus.c @@ -365,6 +365,40 @@ static int amba_pm_restore_noirq(struct device *dev) #endif /* !CONFIG_HIBERNATE_CALLBACKS */ +#ifdef CONFIG_PM_RUNTIME +/* + * Hooks to provide runtime PM of the pclk (bus clock). It is safe to + * enable/disable the bus clock at runtime PM suspend/resume as this + * does not result in loss of context. However, disabling vcore power + * would do, so we leave that to the driver. + */ +static int amba_pm_runtime_suspend(struct device *dev) +{ + struct amba_device *pcdev = to_amba_device(dev); + int ret = pm_generic_runtime_suspend(dev); + + if (ret == 0 && dev->driver) + clk_disable(pcdev->pclk); + + return ret; +} + +static int amba_pm_runtime_resume(struct device *dev) +{ + struct amba_device *pcdev = to_amba_device(dev); + int ret; + + if (dev->driver) { + ret = clk_enable(pcdev->pclk); + /* Failure is probably fatal to the system, but... */ + if (ret) + return ret; + } + + return pm_generic_runtime_resume(dev); +} +#endif + #ifdef CONFIG_PM static const struct dev_pm_ops amba_pm = { @@ -383,8 +417,8 @@ static const struct dev_pm_ops amba_pm = { .poweroff_noirq = amba_pm_poweroff_noirq, .restore_noirq = amba_pm_restore_noirq, SET_RUNTIME_PM_OPS( - pm_generic_runtime_suspend, - pm_generic_runtime_resume, + amba_pm_runtime_suspend, + amba_pm_runtime_resume, pm_generic_runtime_idle ) }; @@ -426,9 +460,17 @@ static int amba_get_enable_pclk(struct amba_device *pcdev) if (IS_ERR(pclk)) return PTR_ERR(pclk); + ret = clk_prepare(pclk); + if (ret) { + clk_put(pclk); + return ret; + } + ret = clk_enable(pclk); - if (ret) + if (ret) { + clk_unprepare(pclk); clk_put(pclk); + } return ret; } @@ -438,6 +480,7 @@ static void amba_put_disable_pclk(struct amba_device *pcdev) struct clk *pclk = pcdev->pclk; clk_disable(pclk); + clk_unprepare(pclk); clk_put(pclk); } @@ -494,10 +537,18 @@ static int amba_probe(struct device *dev) if (ret) break; + pm_runtime_get_noresume(dev); + pm_runtime_set_active(dev); + pm_runtime_enable(dev); + ret = pcdrv->probe(pcdev, id); if (ret == 0) break; + pm_runtime_disable(dev); + pm_runtime_set_suspended(dev); + pm_runtime_put_noidle(dev); + amba_put_disable_pclk(pcdev); amba_put_disable_vcore(pcdev); } while (0); @@ -509,7 +560,16 @@ static int amba_remove(struct device *dev) { struct amba_device *pcdev = to_amba_device(dev); struct amba_driver *drv = to_amba_driver(dev->driver); - int ret = drv->remove(pcdev); + int ret; + + pm_runtime_get_sync(dev); + ret = drv->remove(pcdev); + pm_runtime_put_noidle(dev); + + /* Undo the runtime PM settings in amba_probe() */ + pm_runtime_disable(dev); + pm_runtime_set_suspended(dev); + pm_runtime_put_noidle(dev); amba_put_disable_pclk(pcdev); amba_put_disable_vcore(pcdev); |