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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>
218 lines
5.2 KiB
C
218 lines
5.2 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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//
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// wm831x-isink.c -- Current sink driver for the WM831x series
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//
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// Copyright 2009 Wolfson Microelectronics PLC.
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//
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// Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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#include <linux/module.h>
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#include <linux/moduleparam.h>
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#include <linux/init.h>
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#include <linux/bitops.h>
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#include <linux/err.h>
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#include <linux/i2c.h>
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#include <linux/platform_device.h>
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#include <linux/regulator/driver.h>
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#include <linux/slab.h>
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#include <linux/mfd/wm831x/core.h>
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#include <linux/mfd/wm831x/regulator.h>
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#include <linux/mfd/wm831x/pdata.h>
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#define WM831X_ISINK_MAX_NAME 7
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struct wm831x_isink {
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char name[WM831X_ISINK_MAX_NAME];
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struct regulator_desc desc;
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int reg;
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struct wm831x *wm831x;
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struct regulator_dev *regulator;
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};
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static int wm831x_isink_enable(struct regulator_dev *rdev)
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{
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struct wm831x_isink *isink = rdev_get_drvdata(rdev);
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struct wm831x *wm831x = isink->wm831x;
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int ret;
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/* We have a two stage enable: first start the ISINK... */
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ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA,
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WM831X_CS1_ENA);
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if (ret != 0)
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return ret;
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/* ...then enable drive */
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ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE,
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WM831X_CS1_DRIVE);
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if (ret != 0)
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wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0);
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return ret;
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}
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static int wm831x_isink_disable(struct regulator_dev *rdev)
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{
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struct wm831x_isink *isink = rdev_get_drvdata(rdev);
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struct wm831x *wm831x = isink->wm831x;
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int ret;
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ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_DRIVE, 0);
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if (ret < 0)
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return ret;
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ret = wm831x_set_bits(wm831x, isink->reg, WM831X_CS1_ENA, 0);
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if (ret < 0)
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return ret;
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return ret;
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}
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static int wm831x_isink_is_enabled(struct regulator_dev *rdev)
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{
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struct wm831x_isink *isink = rdev_get_drvdata(rdev);
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struct wm831x *wm831x = isink->wm831x;
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int ret;
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ret = wm831x_reg_read(wm831x, isink->reg);
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if (ret < 0)
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return ret;
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if ((ret & (WM831X_CS1_ENA | WM831X_CS1_DRIVE)) ==
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(WM831X_CS1_ENA | WM831X_CS1_DRIVE))
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return 1;
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else
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return 0;
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}
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static const struct regulator_ops wm831x_isink_ops = {
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.is_enabled = wm831x_isink_is_enabled,
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.enable = wm831x_isink_enable,
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.disable = wm831x_isink_disable,
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.set_current_limit = regulator_set_current_limit_regmap,
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.get_current_limit = regulator_get_current_limit_regmap,
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};
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static irqreturn_t wm831x_isink_irq(int irq, void *data)
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{
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struct wm831x_isink *isink = data;
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regulator_notifier_call_chain(isink->regulator,
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REGULATOR_EVENT_OVER_CURRENT,
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NULL);
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return IRQ_HANDLED;
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}
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static int wm831x_isink_probe(struct platform_device *pdev)
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{
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struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
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struct wm831x_pdata *pdata = dev_get_platdata(wm831x->dev);
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struct wm831x_isink *isink;
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int id = pdev->id % ARRAY_SIZE(pdata->isink);
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struct regulator_config config = { };
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struct resource *res;
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int ret, irq;
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dev_dbg(&pdev->dev, "Probing ISINK%d\n", id + 1);
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if (pdata == NULL || pdata->isink[id] == NULL)
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return -ENODEV;
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isink = devm_kzalloc(&pdev->dev, sizeof(struct wm831x_isink),
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GFP_KERNEL);
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if (!isink)
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return -ENOMEM;
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isink->wm831x = wm831x;
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res = platform_get_resource(pdev, IORESOURCE_REG, 0);
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if (res == NULL) {
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dev_err(&pdev->dev, "No REG resource\n");
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ret = -EINVAL;
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goto err;
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}
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isink->reg = res->start;
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/* For current parts this is correct; probably need to revisit
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* in future.
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*/
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snprintf(isink->name, sizeof(isink->name), "ISINK%d", id + 1);
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isink->desc.name = isink->name;
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isink->desc.id = id;
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isink->desc.ops = &wm831x_isink_ops;
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isink->desc.type = REGULATOR_CURRENT;
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isink->desc.owner = THIS_MODULE;
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isink->desc.curr_table = wm831x_isinkv_values,
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isink->desc.n_current_limits = ARRAY_SIZE(wm831x_isinkv_values),
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isink->desc.csel_reg = isink->reg,
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isink->desc.csel_mask = WM831X_CS1_ISEL_MASK,
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config.dev = pdev->dev.parent;
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config.init_data = pdata->isink[id];
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config.driver_data = isink;
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config.regmap = wm831x->regmap;
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isink->regulator = devm_regulator_register(&pdev->dev, &isink->desc,
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&config);
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if (IS_ERR(isink->regulator)) {
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ret = PTR_ERR(isink->regulator);
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dev_err(wm831x->dev, "Failed to register ISINK%d: %d\n",
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id + 1, ret);
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goto err;
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}
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irq = wm831x_irq(wm831x, platform_get_irq(pdev, 0));
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ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
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wm831x_isink_irq,
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IRQF_TRIGGER_RISING | IRQF_ONESHOT,
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isink->name,
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isink);
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if (ret != 0) {
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dev_err(&pdev->dev, "Failed to request ISINK IRQ %d: %d\n",
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irq, ret);
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goto err;
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}
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platform_set_drvdata(pdev, isink);
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return 0;
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err:
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return ret;
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}
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static struct platform_driver wm831x_isink_driver = {
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.probe = wm831x_isink_probe,
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.driver = {
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.name = "wm831x-isink",
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.probe_type = PROBE_PREFER_ASYNCHRONOUS,
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},
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};
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static int __init wm831x_isink_init(void)
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{
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int ret;
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ret = platform_driver_register(&wm831x_isink_driver);
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if (ret != 0)
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pr_err("Failed to register WM831x ISINK driver: %d\n", ret);
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return ret;
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}
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subsys_initcall(wm831x_isink_init);
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static void __exit wm831x_isink_exit(void)
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{
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platform_driver_unregister(&wm831x_isink_driver);
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}
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module_exit(wm831x_isink_exit);
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/* Module information */
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MODULE_AUTHOR("Mark Brown");
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MODULE_DESCRIPTION("WM831x current sink driver");
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MODULE_LICENSE("GPL");
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MODULE_ALIAS("platform:wm831x-isink");
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