629277b7f5
The devm_clk_get_enabled() helpers: - call devm_clk_get() - call clk_prepare_enable() and register what is needed in order to call clk_disable_unprepare() when needed, as a managed resource. This simplifies the code and avoids the calls to clk_disable_unprepare(). While at it, use dev_err_probe consistently, and use its return value to return the error code. Link: https://lore.kernel.org/lkml/20240510094034.12493-1-linux.amoon@gmail.com/ Signed-off-by: Anand Moon <linux.amoon@gmail.com> Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
510 lines
12 KiB
C
510 lines
12 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Generic Exynos Bus frequency driver with DEVFREQ Framework
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*
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* Copyright (c) 2016 Samsung Electronics Co., Ltd.
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* Author : Chanwoo Choi <cw00.choi@samsung.com>
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*
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* This driver support Exynos Bus frequency feature by using
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* DEVFREQ framework and is based on drivers/devfreq/exynos/exynos4_bus.c.
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*/
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#include <linux/clk.h>
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#include <linux/devfreq.h>
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#include <linux/devfreq-event.h>
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#include <linux/device.h>
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#include <linux/export.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/pm_opp.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/consumer.h>
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#define DEFAULT_SATURATION_RATIO 40
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struct exynos_bus {
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struct device *dev;
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struct platform_device *icc_pdev;
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struct devfreq *devfreq;
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struct devfreq_event_dev **edev;
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unsigned int edev_count;
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struct mutex lock;
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unsigned long curr_freq;
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int opp_token;
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struct clk *clk;
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unsigned int ratio;
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};
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/*
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* Control the devfreq-event device to get the current state of bus
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*/
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#define exynos_bus_ops_edev(ops) \
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static int exynos_bus_##ops(struct exynos_bus *bus) \
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{ \
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int i, ret; \
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\
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for (i = 0; i < bus->edev_count; i++) { \
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if (!bus->edev[i]) \
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continue; \
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ret = devfreq_event_##ops(bus->edev[i]); \
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if (ret < 0) \
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return ret; \
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} \
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\
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return 0; \
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}
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exynos_bus_ops_edev(enable_edev);
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exynos_bus_ops_edev(disable_edev);
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exynos_bus_ops_edev(set_event);
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static int exynos_bus_get_event(struct exynos_bus *bus,
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struct devfreq_event_data *edata)
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{
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struct devfreq_event_data event_data;
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unsigned long load_count = 0, total_count = 0;
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int i, ret = 0;
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for (i = 0; i < bus->edev_count; i++) {
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if (!bus->edev[i])
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continue;
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ret = devfreq_event_get_event(bus->edev[i], &event_data);
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if (ret < 0)
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return ret;
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if (i == 0 || event_data.load_count > load_count) {
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load_count = event_data.load_count;
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total_count = event_data.total_count;
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}
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}
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edata->load_count = load_count;
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edata->total_count = total_count;
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return ret;
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}
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/*
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* devfreq function for both simple-ondemand and passive governor
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*/
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static int exynos_bus_target(struct device *dev, unsigned long *freq, u32 flags)
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{
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struct exynos_bus *bus = dev_get_drvdata(dev);
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struct dev_pm_opp *new_opp;
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int ret = 0;
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/* Get correct frequency for bus. */
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new_opp = devfreq_recommended_opp(dev, freq, flags);
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if (IS_ERR(new_opp)) {
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dev_err(dev, "failed to get recommended opp instance\n");
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return PTR_ERR(new_opp);
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}
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dev_pm_opp_put(new_opp);
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/* Change voltage and frequency according to new OPP level */
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mutex_lock(&bus->lock);
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ret = dev_pm_opp_set_rate(dev, *freq);
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if (!ret)
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bus->curr_freq = *freq;
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mutex_unlock(&bus->lock);
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return ret;
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}
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static int exynos_bus_get_dev_status(struct device *dev,
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struct devfreq_dev_status *stat)
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{
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struct exynos_bus *bus = dev_get_drvdata(dev);
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struct devfreq_event_data edata;
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int ret;
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stat->current_frequency = bus->curr_freq;
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ret = exynos_bus_get_event(bus, &edata);
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if (ret < 0) {
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dev_err(dev, "failed to get event from devfreq-event devices\n");
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stat->total_time = stat->busy_time = 0;
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goto err;
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}
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stat->busy_time = (edata.load_count * 100) / bus->ratio;
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stat->total_time = edata.total_count;
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dev_dbg(dev, "Usage of devfreq-event : %lu/%lu\n", stat->busy_time,
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stat->total_time);
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err:
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ret = exynos_bus_set_event(bus);
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if (ret < 0) {
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dev_err(dev, "failed to set event to devfreq-event devices\n");
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return ret;
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}
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return ret;
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}
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static void exynos_bus_exit(struct device *dev)
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{
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struct exynos_bus *bus = dev_get_drvdata(dev);
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int ret;
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ret = exynos_bus_disable_edev(bus);
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if (ret < 0)
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dev_warn(dev, "failed to disable the devfreq-event devices\n");
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platform_device_unregister(bus->icc_pdev);
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dev_pm_opp_of_remove_table(dev);
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dev_pm_opp_put_regulators(bus->opp_token);
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}
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static void exynos_bus_passive_exit(struct device *dev)
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{
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struct exynos_bus *bus = dev_get_drvdata(dev);
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platform_device_unregister(bus->icc_pdev);
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dev_pm_opp_of_remove_table(dev);
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}
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static int exynos_bus_parent_parse_of(struct device_node *np,
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struct exynos_bus *bus)
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{
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struct device *dev = bus->dev;
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const char *supplies[] = { "vdd", NULL };
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int i, ret, count, size;
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ret = dev_pm_opp_set_regulators(dev, supplies);
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if (ret < 0) {
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dev_err(dev, "failed to set regulators %d\n", ret);
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return ret;
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}
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bus->opp_token = ret;
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/*
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* Get the devfreq-event devices to get the current utilization of
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* buses. This raw data will be used in devfreq ondemand governor.
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*/
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count = devfreq_event_get_edev_count(dev, "devfreq-events");
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if (count < 0) {
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dev_err(dev, "failed to get the count of devfreq-event dev\n");
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ret = count;
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goto err_regulator;
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}
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bus->edev_count = count;
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size = sizeof(*bus->edev) * count;
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bus->edev = devm_kzalloc(dev, size, GFP_KERNEL);
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if (!bus->edev) {
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ret = -ENOMEM;
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goto err_regulator;
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}
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for (i = 0; i < count; i++) {
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bus->edev[i] = devfreq_event_get_edev_by_phandle(dev,
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"devfreq-events", i);
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if (IS_ERR(bus->edev[i])) {
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ret = -EPROBE_DEFER;
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goto err_regulator;
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}
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}
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/*
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* Optionally, Get the saturation ratio according to Exynos SoC
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* When measuring the utilization of each AXI bus with devfreq-event
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* devices, the measured real cycle might be much lower than the
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* total cycle of bus during sampling rate. In result, the devfreq
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* simple-ondemand governor might not decide to change the current
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* frequency due to too utilization (= real cycle/total cycle).
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* So, this property is used to adjust the utilization when calculating
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* the busy_time in exynos_bus_get_dev_status().
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*/
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if (of_property_read_u32(np, "exynos,saturation-ratio", &bus->ratio))
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bus->ratio = DEFAULT_SATURATION_RATIO;
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return 0;
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err_regulator:
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dev_pm_opp_put_regulators(bus->opp_token);
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return ret;
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}
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static int exynos_bus_parse_of(struct device_node *np,
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struct exynos_bus *bus)
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{
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struct device *dev = bus->dev;
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struct dev_pm_opp *opp;
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unsigned long rate;
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int ret;
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/* Get the clock to provide each bus with source clock */
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bus->clk = devm_clk_get_enabled(dev, "bus");
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if (IS_ERR(bus->clk))
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return dev_err_probe(dev, PTR_ERR(bus->clk),
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"failed to get bus clock\n");
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/* Get the freq and voltage from OPP table to scale the bus freq */
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ret = dev_pm_opp_of_add_table(dev);
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if (ret < 0) {
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dev_err(dev, "failed to get OPP table\n");
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return ret;
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}
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rate = clk_get_rate(bus->clk);
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opp = devfreq_recommended_opp(dev, &rate, 0);
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if (IS_ERR(opp)) {
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dev_err(dev, "failed to find dev_pm_opp\n");
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ret = PTR_ERR(opp);
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goto err_opp;
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}
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bus->curr_freq = dev_pm_opp_get_freq(opp);
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dev_pm_opp_put(opp);
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return 0;
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err_opp:
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dev_pm_opp_of_remove_table(dev);
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return ret;
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}
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static int exynos_bus_profile_init(struct exynos_bus *bus,
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struct devfreq_dev_profile *profile)
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{
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struct device *dev = bus->dev;
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struct devfreq_simple_ondemand_data *ondemand_data;
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int ret;
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/* Initialize the struct profile and governor data for parent device */
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profile->polling_ms = 50;
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profile->target = exynos_bus_target;
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profile->get_dev_status = exynos_bus_get_dev_status;
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profile->exit = exynos_bus_exit;
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ondemand_data = devm_kzalloc(dev, sizeof(*ondemand_data), GFP_KERNEL);
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if (!ondemand_data)
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return -ENOMEM;
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ondemand_data->upthreshold = 40;
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ondemand_data->downdifferential = 5;
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/* Add devfreq device to monitor and handle the exynos bus */
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bus->devfreq = devm_devfreq_add_device(dev, profile,
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DEVFREQ_GOV_SIMPLE_ONDEMAND,
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ondemand_data);
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if (IS_ERR(bus->devfreq)) {
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dev_err(dev, "failed to add devfreq device\n");
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return PTR_ERR(bus->devfreq);
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}
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/* Register opp_notifier to catch the change of OPP */
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ret = devm_devfreq_register_opp_notifier(dev, bus->devfreq);
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if (ret < 0) {
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dev_err(dev, "failed to register opp notifier\n");
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return ret;
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}
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/*
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* Enable devfreq-event to get raw data which is used to determine
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* current bus load.
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*/
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ret = exynos_bus_enable_edev(bus);
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if (ret < 0) {
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dev_err(dev, "failed to enable devfreq-event devices\n");
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return ret;
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}
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ret = exynos_bus_set_event(bus);
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if (ret < 0) {
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dev_err(dev, "failed to set event to devfreq-event devices\n");
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goto err_edev;
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}
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return 0;
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err_edev:
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if (exynos_bus_disable_edev(bus))
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dev_warn(dev, "failed to disable the devfreq-event devices\n");
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return ret;
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}
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static int exynos_bus_profile_init_passive(struct exynos_bus *bus,
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struct devfreq_dev_profile *profile)
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{
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struct device *dev = bus->dev;
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struct devfreq_passive_data *passive_data;
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struct devfreq *parent_devfreq;
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/* Initialize the struct profile and governor data for passive device */
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profile->target = exynos_bus_target;
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profile->exit = exynos_bus_passive_exit;
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/* Get the instance of parent devfreq device */
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parent_devfreq = devfreq_get_devfreq_by_phandle(dev, "devfreq", 0);
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if (IS_ERR(parent_devfreq))
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return -EPROBE_DEFER;
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passive_data = devm_kzalloc(dev, sizeof(*passive_data), GFP_KERNEL);
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if (!passive_data)
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return -ENOMEM;
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passive_data->parent = parent_devfreq;
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/* Add devfreq device for exynos bus with passive governor */
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bus->devfreq = devm_devfreq_add_device(dev, profile, DEVFREQ_GOV_PASSIVE,
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passive_data);
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if (IS_ERR(bus->devfreq)) {
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dev_err(dev,
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"failed to add devfreq dev with passive governor\n");
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return PTR_ERR(bus->devfreq);
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}
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return 0;
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}
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static int exynos_bus_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct device_node *np = dev->of_node, *node;
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struct devfreq_dev_profile *profile;
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struct exynos_bus *bus;
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int ret, max_state;
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unsigned long min_freq, max_freq;
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bool passive = false;
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if (!np) {
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dev_err(dev, "failed to find devicetree node\n");
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return -EINVAL;
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}
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bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
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if (!bus)
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return -ENOMEM;
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mutex_init(&bus->lock);
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bus->dev = &pdev->dev;
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platform_set_drvdata(pdev, bus);
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profile = devm_kzalloc(dev, sizeof(*profile), GFP_KERNEL);
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if (!profile)
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return -ENOMEM;
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node = of_parse_phandle(dev->of_node, "devfreq", 0);
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if (node) {
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of_node_put(node);
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passive = true;
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} else {
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ret = exynos_bus_parent_parse_of(np, bus);
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if (ret < 0)
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return ret;
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}
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/* Parse the device-tree to get the resource information */
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ret = exynos_bus_parse_of(np, bus);
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if (ret < 0)
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goto err_reg;
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if (passive)
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ret = exynos_bus_profile_init_passive(bus, profile);
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else
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ret = exynos_bus_profile_init(bus, profile);
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if (ret < 0)
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goto err;
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/* Create child platform device for the interconnect provider */
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if (of_property_present(dev->of_node, "#interconnect-cells")) {
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bus->icc_pdev = platform_device_register_data(
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dev, "exynos-generic-icc",
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PLATFORM_DEVID_AUTO, NULL, 0);
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if (IS_ERR(bus->icc_pdev)) {
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ret = PTR_ERR(bus->icc_pdev);
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goto err;
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}
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}
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max_state = bus->devfreq->max_state;
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min_freq = (bus->devfreq->freq_table[0] / 1000);
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max_freq = (bus->devfreq->freq_table[max_state - 1] / 1000);
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pr_info("exynos-bus: new bus device registered: %s (%6ld KHz ~ %6ld KHz)\n",
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dev_name(dev), min_freq, max_freq);
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return 0;
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err:
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dev_pm_opp_of_remove_table(dev);
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err_reg:
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dev_pm_opp_put_regulators(bus->opp_token);
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return ret;
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}
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static void exynos_bus_shutdown(struct platform_device *pdev)
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{
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struct exynos_bus *bus = dev_get_drvdata(&pdev->dev);
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devfreq_suspend_device(bus->devfreq);
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}
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static int exynos_bus_resume(struct device *dev)
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{
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struct exynos_bus *bus = dev_get_drvdata(dev);
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int ret;
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ret = exynos_bus_enable_edev(bus);
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if (ret < 0) {
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dev_err(dev, "failed to enable the devfreq-event devices\n");
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return ret;
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}
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return 0;
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}
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static int exynos_bus_suspend(struct device *dev)
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{
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struct exynos_bus *bus = dev_get_drvdata(dev);
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int ret;
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ret = exynos_bus_disable_edev(bus);
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if (ret < 0) {
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dev_err(dev, "failed to disable the devfreq-event devices\n");
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return ret;
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}
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return 0;
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}
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static DEFINE_SIMPLE_DEV_PM_OPS(exynos_bus_pm,
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exynos_bus_suspend, exynos_bus_resume);
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static const struct of_device_id exynos_bus_of_match[] = {
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{ .compatible = "samsung,exynos-bus", },
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{ /* sentinel */ },
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};
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MODULE_DEVICE_TABLE(of, exynos_bus_of_match);
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static struct platform_driver exynos_bus_platdrv = {
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.probe = exynos_bus_probe,
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.shutdown = exynos_bus_shutdown,
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.driver = {
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.name = "exynos-bus",
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.pm = pm_sleep_ptr(&exynos_bus_pm),
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.of_match_table = exynos_bus_of_match,
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},
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};
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module_platform_driver(exynos_bus_platdrv);
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MODULE_SOFTDEP("pre: exynos_ppmu");
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MODULE_DESCRIPTION("Generic Exynos Bus frequency driver");
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MODULE_AUTHOR("Chanwoo Choi <cw00.choi@samsung.com>");
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MODULE_LICENSE("GPL v2");
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