diff options
Diffstat (limited to 'arch/arm/mach-shmobile/pm_runtime.c')
| -rw-r--r-- | arch/arm/mach-shmobile/pm_runtime.c | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/arch/arm/mach-shmobile/pm_runtime.c b/arch/arm/mach-shmobile/pm_runtime.c new file mode 100644 index 000000000000..94912d3944d3 --- /dev/null +++ b/arch/arm/mach-shmobile/pm_runtime.c @@ -0,0 +1,169 @@ +/* + * arch/arm/mach-shmobile/pm_runtime.c + * + * Runtime PM support code for SuperH Mobile ARM + * + * Copyright (C) 2009-2010 Magnus Damm + * + * This file is subject to the terms and conditions of the GNU General Public + * License. See the file "COPYING" in the main directory of this archive + * for more details. + */ + +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/io.h> +#include <linux/pm_runtime.h> +#include <linux/platform_device.h> +#include <linux/clk.h> +#include <linux/sh_clk.h> +#include <linux/bitmap.h> + +#ifdef CONFIG_PM_RUNTIME +#define BIT_ONCE 0 +#define BIT_ACTIVE 1 +#define BIT_CLK_ENABLED 2 + +struct pm_runtime_data { + unsigned long flags; + struct clk *clk; +}; + +static void __devres_release(struct device *dev, void *res) +{ + struct pm_runtime_data *prd = res; + + dev_dbg(dev, "__devres_release()\n"); + + if (test_bit(BIT_CLK_ENABLED, &prd->flags)) + clk_disable(prd->clk); + + if (test_bit(BIT_ACTIVE, &prd->flags)) + clk_put(prd->clk); +} + +static struct pm_runtime_data *__to_prd(struct device *dev) +{ + return devres_find(dev, __devres_release, NULL, NULL); +} + +static void platform_pm_runtime_init(struct device *dev, + struct pm_runtime_data *prd) +{ + if (prd && !test_and_set_bit(BIT_ONCE, &prd->flags)) { + prd->clk = clk_get(dev, NULL); + if (!IS_ERR(prd->clk)) { + set_bit(BIT_ACTIVE, &prd->flags); + dev_info(dev, "clocks managed by runtime pm\n"); + } + } +} + +static void platform_pm_runtime_bug(struct device *dev, + struct pm_runtime_data *prd) +{ + if (prd && !test_and_set_bit(BIT_ONCE, &prd->flags)) + dev_err(dev, "runtime pm suspend before resume\n"); +} + +int platform_pm_runtime_suspend(struct device *dev) +{ + struct pm_runtime_data *prd = __to_prd(dev); + + dev_dbg(dev, "platform_pm_runtime_suspend()\n"); + + platform_pm_runtime_bug(dev, prd); + + if (prd && test_bit(BIT_ACTIVE, &prd->flags)) { + clk_disable(prd->clk); + clear_bit(BIT_CLK_ENABLED, &prd->flags); + } + + return 0; +} + +int platform_pm_runtime_resume(struct device *dev) +{ + struct pm_runtime_data *prd = __to_prd(dev); + + dev_dbg(dev, "platform_pm_runtime_resume()\n"); + + platform_pm_runtime_init(dev, prd); + + if (prd && test_bit(BIT_ACTIVE, &prd->flags)) { + clk_enable(prd->clk); + set_bit(BIT_CLK_ENABLED, &prd->flags); + } + + return 0; +} + +int platform_pm_runtime_idle(struct device *dev) +{ + /* suspend synchronously to disable clocks immediately */ + return pm_runtime_suspend(dev); +} + +static int platform_bus_notify(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *dev = data; + struct pm_runtime_data *prd; + + dev_dbg(dev, "platform_bus_notify() %ld !\n", action); + + if (action == BUS_NOTIFY_BIND_DRIVER) { + prd = devres_alloc(__devres_release, sizeof(*prd), GFP_KERNEL); + if (prd) + devres_add(dev, prd); + else + dev_err(dev, "unable to alloc memory for runtime pm\n"); + } + + return 0; +} + +#else /* CONFIG_PM_RUNTIME */ + +static int platform_bus_notify(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct device *dev = data; + struct clk *clk; + + dev_dbg(dev, "platform_bus_notify() %ld !\n", action); + + switch (action) { + case BUS_NOTIFY_BIND_DRIVER: + clk = clk_get(dev, NULL); + if (!IS_ERR(clk)) { + clk_enable(clk); + clk_put(clk); + dev_info(dev, "runtime pm disabled, clock forced on\n"); + } + break; + case BUS_NOTIFY_UNBOUND_DRIVER: + clk = clk_get(dev, NULL); + if (!IS_ERR(clk)) { + clk_disable(clk); + clk_put(clk); + dev_info(dev, "runtime pm disabled, clock forced off\n"); + } + break; + } + + return 0; +} + +#endif /* CONFIG_PM_RUNTIME */ + +static struct notifier_block platform_bus_notifier = { + .notifier_call = platform_bus_notify +}; + +static int __init sh_pm_runtime_init(void) +{ + bus_register_notifier(&platform_bus_type, &platform_bus_notifier); + return 0; +} +core_initcall(sh_pm_runtime_init); |