diff --git a/drivers/devfreq/Kconfig b/drivers/devfreq/Kconfig index 07b773353429..c547184fac53 100644 --- a/drivers/devfreq/Kconfig +++ b/drivers/devfreq/Kconfig @@ -106,6 +106,16 @@ config ARM_TEGRA_DEVFREQ It reads ACTMON counters of memory controllers and adjusts the operating frequencies and voltages with OPP support. +config DEVFREQ_SIMPLE_DEV + tristate "Device driver for simple clock device with no status info" + select DEVFREQ_GOV_PERFORMANCE + select DEVFREQ_GOV_POWERSAVE + select DEVFREQ_GOV_USERSPACE + select DEVFREQ_GOV_CPUFREQ + help + Device driver for simple devices that control their frequency using + clock APIs and don't have any form of status reporting. + source "drivers/devfreq/event/Kconfig" endif # PM_DEVFREQ diff --git a/drivers/devfreq/Makefile b/drivers/devfreq/Makefile index 6b591818fd09..ebe328713e5d 100644 --- a/drivers/devfreq/Makefile +++ b/drivers/devfreq/Makefile @@ -10,6 +10,7 @@ obj-$(CONFIG_DEVFREQ_GOV_QCOM_ADRENO_TZ) += governor_msm_adreno_tz.o obj-$(CONFIG_ARM_EXYNOS4_BUS_DEVFREQ) += exynos/ obj-$(CONFIG_ARM_EXYNOS5_BUS_DEVFREQ) += exynos/ obj-$(CONFIG_ARM_TEGRA_DEVFREQ) += tegra-devfreq.o +obj-$(CONFIG_DEVFREQ_SIMPLE_DEV) += devfreq_simple_dev.o # DEVFREQ Event Drivers obj-$(CONFIG_PM_DEVFREQ_EVENT) += event/ diff --git a/drivers/devfreq/devfreq_simple_dev.c b/drivers/devfreq/devfreq_simple_dev.c new file mode 100644 index 000000000000..a571867335ca --- /dev/null +++ b/drivers/devfreq/devfreq_simple_dev.c @@ -0,0 +1,193 @@ +/* + * Copyright (c) 2014, The Linux Foundation. All rights reserved. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 and + * only version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#define pr_fmt(fmt) "devfreq-simple-dev: " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +struct dev_data { + struct clk *clk; + struct devfreq *df; + struct devfreq_dev_profile profile; +}; + +static void find_freq(struct devfreq_dev_profile *p, unsigned long *freq, + u32 flags) +{ + int i; + unsigned long atmost, atleast, f; + + atmost = p->freq_table[0]; + atleast = p->freq_table[p->max_state-1]; + for (i = 0; i < p->max_state; i++) { + f = p->freq_table[i]; + if (f <= *freq) + atmost = max(f, atmost); + if (f >= *freq) + atleast = min(f, atleast); + } + + if (flags & DEVFREQ_FLAG_LEAST_UPPER_BOUND) + *freq = atmost; + else + *freq = atleast; +} + +static int dev_target(struct device *dev, unsigned long *freq, u32 flags) +{ + struct dev_data *d = dev_get_drvdata(dev); + + find_freq(&d->profile, freq, flags); + return clk_set_rate(d->clk, *freq * 1000); +} + +static int dev_get_cur_freq(struct device *dev, unsigned long *freq) +{ + struct dev_data *d = dev_get_drvdata(dev); + unsigned long f; + + f = clk_get_rate(d->clk); + if (IS_ERR_VALUE(f)) + return f; + *freq = f / 1000; + return 0; +} + +#define PROP_TBL "freq-tbl-khz" +static int devfreq_clock_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct dev_data *d; + struct devfreq_dev_profile *p; + u32 *data, poll; + const char *gov_name; + int ret, len, i, j; + unsigned long f; + + d = devm_kzalloc(dev, sizeof(*d), GFP_KERNEL); + if (!d) + return -ENOMEM; + platform_set_drvdata(pdev, d); + + d->clk = devm_clk_get(dev, "devfreq_clk"); + if (IS_ERR(d->clk)) + return PTR_ERR(d->clk); + + if (!of_find_property(dev->of_node, PROP_TBL, &len)) + return -EINVAL; + + len /= sizeof(*data); + data = devm_kzalloc(dev, len * sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + p = &d->profile; + p->freq_table = devm_kzalloc(dev, len * sizeof(*p->freq_table), + GFP_KERNEL); + if (!p->freq_table) + return -ENOMEM; + + ret = of_property_read_u32_array(dev->of_node, PROP_TBL, data, len); + if (ret) + return ret; + + j = 0; + for (i = 0; i < len; i++) { + f = clk_round_rate(d->clk, data[i] * 1000); + if (IS_ERR_VALUE(f)) + dev_warn(dev, "Unable to find dev rate for %d KHz", + data[i]); + else + p->freq_table[j++] = f / 1000; + } + p->max_state = j; + devm_kfree(dev, data); + + if (p->max_state == 0) { + dev_err(dev, "Error parsing property %s!\n", PROP_TBL); + return -EINVAL; + } + + p->target = dev_target; + p->get_cur_freq = dev_get_cur_freq; + ret = dev_get_cur_freq(dev, &p->initial_freq); + if (ret) + return ret; + + p->polling_ms = 50; + if (!of_property_read_u32(dev->of_node, "polling-ms", &poll)) + p->polling_ms = poll; + + if (of_property_read_string(dev->of_node, "governor", &gov_name)) + gov_name = "performance"; + + + d->df = devfreq_add_device(dev, p, gov_name, NULL); + if (IS_ERR(d->df)) + return PTR_ERR(d->df); + + return 0; +} + +static int devfreq_clock_remove(struct platform_device *pdev) +{ + struct dev_data *d = platform_get_drvdata(pdev); + devfreq_remove_device(d->df); + return 0; +} + +static struct of_device_id match_table[] = { + { .compatible = "devfreq-simple-dev" }, + {} +}; + +static struct platform_driver devfreq_clock_driver = { + .probe = devfreq_clock_probe, + .remove = devfreq_clock_remove, + .driver = { + .name = "devfreq-simple-dev", + .of_match_table = match_table, + .owner = THIS_MODULE, + }, +}; + +static int __init devfreq_clock_init(void) +{ + platform_driver_register(&devfreq_clock_driver); + return 0; +} +device_initcall(devfreq_clock_init); + +static void __exit devfreq_clock_exit(void) +{ + platform_driver_unregister(&devfreq_clock_driver); +} +module_exit(devfreq_clock_exit); + +MODULE_DESCRIPTION("Devfreq driver for setting generic device clock frequency"); +MODULE_LICENSE("GPL v2");