diff options
Diffstat (limited to 'arch/arm/plat-mxc/cpuidle.c')
| -rw-r--r-- | arch/arm/plat-mxc/cpuidle.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/arch/arm/plat-mxc/cpuidle.c b/arch/arm/plat-mxc/cpuidle.c new file mode 100644 index 00000000000..40c192420f4 --- /dev/null +++ b/arch/arm/plat-mxc/cpuidle.c @@ -0,0 +1,159 @@ +/* + * Copyright 2011 Freescale Semiconductor, Inc. + * Copyright 2011 Linaro Ltd. + * + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ + +#include <linux/kernel.h> +#include <linux/io.h> +#include <linux/cpuidle.h> +#include <linux/err.h> +#include <asm/proc-fns.h> +#include <mach/cpuidle.h> + +static int (*mach_cpuidle)(struct cpuidle_device *dev, + struct cpuidle_state *state); +static struct cpuidle_driver *imx_cpuidle_driver; +static struct cpuidle_device *device; + +static int imx_enter_idle(struct cpuidle_device *dev, + struct cpuidle_state *state) +{ + struct timeval before, after; + int idle_time; + + local_irq_disable(); + local_fiq_disable(); + + do_gettimeofday(&before); + + mach_cpuidle(dev, state); + + do_gettimeofday(&after); + + local_fiq_enable(); + local_irq_enable(); + + idle_time = (after.tv_sec - before.tv_sec) * USEC_PER_SEC + + (after.tv_usec - before.tv_usec); + + return idle_time; +} + +static DEFINE_PER_CPU(struct cpuidle_device, imx_cpuidle_device); + +int __init imx_cpuidle_init(struct imx_cpuidle_data *cpuidle_data) +{ + int i, cpu_id; + + if (cpuidle_data == NULL) { + pr_err("%s: cpuidle_data pointer NULL\n", __func__); + return -EINVAL; + } + + if (cpuidle_data->mach_cpuidle == NULL) { + pr_err("%s: idle callback function NULL\n", __func__); + return -EINVAL; + } + + imx_cpuidle_driver = cpuidle_data->imx_cpuidle_driver; + + mach_cpuidle = cpuidle_data->mach_cpuidle; + + /* register imx_cpuidle driver */ + if (cpuidle_register_driver(imx_cpuidle_driver)) { + pr_err("%s: Failed to register cpuidle driver\n", __func__); + return -ENODEV; + } + + /* if provided, initialize the mach level cpuidle functionality */ + if (cpuidle_data->mach_cpuidle_init) { + if (cpuidle_data->mach_cpuidle_init(cpuidle_data)) { + pr_err("%s: Failed to register cpuidle driver\n", + __func__); + cpuidle_unregister_driver(imx_cpuidle_driver); + return -ENODEV; + } + } + + /* initialize state data for each cpuidle_device(one per present cpu)*/ + for_each_cpu(cpu_id, cpu_present_mask) { + + device = &per_cpu(imx_cpuidle_device, cpu_id); + device->cpu = cpu_id; + + device->state_count = min((unsigned int) CPUIDLE_STATE_MAX, + cpuidle_data->num_states); + + device->prepare = cpuidle_data->prepare; + + for (i = 0; i < device->state_count; i++) { + strlcpy(device->states[i].name, + cpuidle_data->state_data[i].name, + CPUIDLE_NAME_LEN); + + strlcpy(device->states[i].desc, + cpuidle_data->state_data[i].desc, + CPUIDLE_DESC_LEN); + + device->states[i].driver_data = + (void *)cpuidle_data-> + state_data[i].mach_cpu_pwr_state; + + /* + * Because the imx_enter_idle function measures + * and returns a valid time for all imx SoCs, + * we always set this flag. + */ + device->states[i].flags = CPUIDLE_FLAG_TIME_VALID; + + device->states[i].exit_latency = + cpuidle_data->state_data[i].exit_latency; + + device->states[i].power_usage = + cpuidle_data->state_data[i].power_usage; + + device->states[i].target_residency = + cpuidle_data->state_data[i].target_residency; + + device->states[i].enter = imx_enter_idle; + } + } + + return 0; +} + +int __init imx_cpuidle_dev_init(void) +{ + int cpu_id; + + /* + * Register online cpus. If maxcpus is specified as a boot + * argument and secondary cpus are brought online after boot, + * this function can be called again to register a cpuidle + * device for those secondary cpus. + */ + for_each_cpu(cpu_id, cpu_online_mask) { + device = &per_cpu(imx_cpuidle_device, cpu_id); + if (device == NULL) { + pr_err("%s: Failed to register (No device)\n", + __func__); + return -ENODEV; + } + + if (!device->registered) + if (cpuidle_register_device(device)) { + pr_err("%s: Failed to register\n", __func__); + return -ENODEV; + } + } + + return 0; +} +late_initcall(imx_cpuidle_dev_init); |