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259b93b21a
Probing of regulators can be a slow operation and can contribute to slower boot times. This is especially true if a regulator is turned on at probe time (with regulator-boot-on or regulator-always-on) and the regulator requires delays (off-on-time, ramp time, etc). While the overall kernel is not ready to switch to async probe by default, as per the discussion on the mailing lists [1] it is believed that the regulator subsystem is in good shape and we can move regulator drivers over wholesale. There is no way to just magically opt in all regulators (regulators are just normal drivers like platform_driver), so we set PROBE_PREFER_ASYNCHRONOUS for all regulators found in 'drivers/regulator' individually. Given the number of drivers touched and the impossibility to test this ahead of time, it wouldn't be shocking at all if this caused a regression for someone. If there is a regression caused by this patch, it's likely to be one of the cases talked about in [1]. As a "quick fix", drivers involved in the regression could be fixed by changing them to PROBE_FORCE_SYNCHRONOUS. That being said, the correct fix would be to directly fix the problem that caused the issue with async probe. The approach here follows a similar approach that was used for the mmc subsystem several years ago [2]. In fact, I ran nearly the same python script to auto-generate the changes. The only thing I changed was to search for "i2c_driver", "spmi_driver", and "spi_driver" in addition to "platform_driver". [1] https://lore.kernel.org/r/06db017f-e985-4434-8d1d-02ca2100cca0@sirena.org.uk [2] https://lore.kernel.org/r/20200903232441.2694866-1-dianders@chromium.org/ Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20230316125351.1.I2a4677392a38db5758dee0788b2cea5872562a82@changeid Signed-off-by: Mark Brown <broonie@kernel.org>
228 lines
5.5 KiB
C
228 lines
5.5 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/*
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* userspace-consumer.c
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*
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* Copyright 2009 CompuLab, Ltd.
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*
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* Author: Mike Rapoport <mike@compulab.co.il>
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*
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* Based of virtual consumer driver:
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* Copyright 2008 Wolfson Microelectronics PLC.
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* Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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*/
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#include <linux/err.h>
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#include <linux/mutex.h>
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#include <linux/module.h>
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#include <linux/of.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/consumer.h>
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#include <linux/regulator/userspace-consumer.h>
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#include <linux/slab.h>
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struct userspace_consumer_data {
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const char *name;
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struct mutex lock;
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bool enabled;
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bool no_autoswitch;
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int num_supplies;
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struct regulator_bulk_data *supplies;
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};
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static ssize_t name_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct userspace_consumer_data *data = dev_get_drvdata(dev);
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return sprintf(buf, "%s\n", data->name);
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}
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static ssize_t state_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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struct userspace_consumer_data *data = dev_get_drvdata(dev);
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if (data->enabled)
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return sprintf(buf, "enabled\n");
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return sprintf(buf, "disabled\n");
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}
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static ssize_t state_store(struct device *dev, struct device_attribute *attr,
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const char *buf, size_t count)
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{
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struct userspace_consumer_data *data = dev_get_drvdata(dev);
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bool enabled;
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int ret;
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/*
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* sysfs_streq() doesn't need the \n's, but we add them so the strings
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* will be shared with show_state(), above.
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*/
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if (sysfs_streq(buf, "enabled\n") || sysfs_streq(buf, "1"))
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enabled = true;
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else if (sysfs_streq(buf, "disabled\n") || sysfs_streq(buf, "0"))
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enabled = false;
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else {
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dev_err(dev, "Configuring invalid mode\n");
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return count;
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}
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mutex_lock(&data->lock);
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if (enabled != data->enabled) {
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if (enabled)
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ret = regulator_bulk_enable(data->num_supplies,
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data->supplies);
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else
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ret = regulator_bulk_disable(data->num_supplies,
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data->supplies);
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if (ret == 0)
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data->enabled = enabled;
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else
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dev_err(dev, "Failed to configure state: %d\n", ret);
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}
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mutex_unlock(&data->lock);
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return count;
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}
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static DEVICE_ATTR_RO(name);
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static DEVICE_ATTR_RW(state);
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static struct attribute *attributes[] = {
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&dev_attr_name.attr,
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&dev_attr_state.attr,
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NULL,
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};
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static umode_t attr_visible(struct kobject *kobj, struct attribute *attr, int idx)
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{
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struct device *dev = kobj_to_dev(kobj);
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struct userspace_consumer_data *data = dev_get_drvdata(dev);
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/* If a name hasn't been set, don't bother with the attribute */
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if (attr == &dev_attr_name.attr && !data->name)
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return 0;
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return attr->mode;
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}
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static const struct attribute_group attr_group = {
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.attrs = attributes,
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.is_visible = attr_visible,
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};
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static int regulator_userspace_consumer_probe(struct platform_device *pdev)
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{
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struct regulator_userspace_consumer_data tmpdata;
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struct regulator_userspace_consumer_data *pdata;
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struct userspace_consumer_data *drvdata;
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int ret;
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pdata = dev_get_platdata(&pdev->dev);
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if (!pdata) {
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if (!pdev->dev.of_node)
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return -EINVAL;
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pdata = &tmpdata;
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memset(pdata, 0, sizeof(*pdata));
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pdata->no_autoswitch = true;
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pdata->num_supplies = 1;
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pdata->supplies = devm_kzalloc(&pdev->dev, sizeof(*pdata->supplies), GFP_KERNEL);
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if (!pdata->supplies)
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return -ENOMEM;
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pdata->supplies[0].supply = "vout";
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}
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if (pdata->num_supplies < 1) {
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dev_err(&pdev->dev, "At least one supply required\n");
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return -EINVAL;
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}
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drvdata = devm_kzalloc(&pdev->dev,
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sizeof(struct userspace_consumer_data),
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GFP_KERNEL);
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if (drvdata == NULL)
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return -ENOMEM;
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drvdata->name = pdata->name;
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drvdata->num_supplies = pdata->num_supplies;
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drvdata->supplies = pdata->supplies;
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drvdata->no_autoswitch = pdata->no_autoswitch;
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mutex_init(&drvdata->lock);
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ret = devm_regulator_bulk_get_exclusive(&pdev->dev, drvdata->num_supplies,
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drvdata->supplies);
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if (ret) {
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dev_err(&pdev->dev, "Failed to get supplies: %d\n", ret);
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return ret;
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}
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platform_set_drvdata(pdev, drvdata);
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ret = sysfs_create_group(&pdev->dev.kobj, &attr_group);
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if (ret != 0)
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return ret;
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if (pdata->init_on && !pdata->no_autoswitch) {
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ret = regulator_bulk_enable(drvdata->num_supplies,
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drvdata->supplies);
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if (ret) {
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dev_err(&pdev->dev,
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"Failed to set initial state: %d\n", ret);
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goto err_enable;
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}
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}
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ret = regulator_is_enabled(pdata->supplies[0].consumer);
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if (ret < 0) {
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dev_err(&pdev->dev, "Failed to get regulator status\n");
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goto err_enable;
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}
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drvdata->enabled = !!ret;
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return 0;
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err_enable:
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sysfs_remove_group(&pdev->dev.kobj, &attr_group);
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return ret;
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}
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static int regulator_userspace_consumer_remove(struct platform_device *pdev)
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{
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struct userspace_consumer_data *data = platform_get_drvdata(pdev);
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sysfs_remove_group(&pdev->dev.kobj, &attr_group);
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if (data->enabled && !data->no_autoswitch)
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regulator_bulk_disable(data->num_supplies, data->supplies);
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return 0;
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}
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static const struct of_device_id regulator_userspace_consumer_of_match[] = {
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{ .compatible = "regulator-output", },
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{},
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};
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static struct platform_driver regulator_userspace_consumer_driver = {
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.probe = regulator_userspace_consumer_probe,
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.remove = regulator_userspace_consumer_remove,
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.driver = {
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.name = "reg-userspace-consumer",
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.probe_type = PROBE_PREFER_ASYNCHRONOUS,
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.of_match_table = regulator_userspace_consumer_of_match,
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},
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};
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module_platform_driver(regulator_userspace_consumer_driver);
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MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
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MODULE_DESCRIPTION("Userspace consumer for voltage and current regulators");
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MODULE_LICENSE("GPL");
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