![Guenter Roeck](/assets/img/avatar_default.png)
The HWMON_CHANNEL_INFO macro simplifies the code, reduces the likelihood of errors, and makes the code easier to read. The conversion was done automatically with coccinelle. The semantic patch used to make this change is as follows. @r@ initializer list elements; identifier i; @@ -u32 i[] = { - elements, - 0 -}; @s@ identifier r.i,j,ty; @@ -struct hwmon_channel_info j = { - .type = ty, - .config = i, -}; @script:ocaml t@ ty << s.ty; elements << r.elements; shorter; elems; @@ shorter := make_ident (List.hd(List.rev (Str.split (Str.regexp "_") ty))); elems := make_ident (String.concat "," (List.map (fun x -> Printf.sprintf "\n\t\t\t %s" x) (Str.split (Str.regexp " , ") elements))) @@ identifier s.j,t.shorter; identifier t.elems; @@ - &j + HWMON_CHANNEL_INFO(shorter,elems) This patch does not introduce functional changes. Many thanks to Julia Lawall for providing the semantic patch. Signed-off-by: Guenter Roeck <linux@roeck-us.net>
153 lines
3.6 KiB
C
153 lines
3.6 KiB
C
// SPDX-License-Identifier: GPL-2.0+
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/*
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* Raspberry Pi voltage sensor driver
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*
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* Based on firmware/raspberrypi.c by Noralf Trønnes
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*
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* Copyright (C) 2018 Stefan Wahren <stefan.wahren@i2se.com>
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*/
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#include <linux/device.h>
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#include <linux/err.h>
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#include <linux/hwmon.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/slab.h>
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#include <linux/workqueue.h>
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#include <soc/bcm2835/raspberrypi-firmware.h>
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#define UNDERVOLTAGE_STICKY_BIT BIT(16)
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struct rpi_hwmon_data {
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struct device *hwmon_dev;
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struct rpi_firmware *fw;
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u32 last_throttled;
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struct delayed_work get_values_poll_work;
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};
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static void rpi_firmware_get_throttled(struct rpi_hwmon_data *data)
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{
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u32 new_uv, old_uv, value;
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int ret;
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/* Request firmware to clear sticky bits */
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value = 0xffff;
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ret = rpi_firmware_property(data->fw, RPI_FIRMWARE_GET_THROTTLED,
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&value, sizeof(value));
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if (ret) {
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dev_err_once(data->hwmon_dev, "Failed to get throttled (%d)\n",
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ret);
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return;
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}
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new_uv = value & UNDERVOLTAGE_STICKY_BIT;
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old_uv = data->last_throttled & UNDERVOLTAGE_STICKY_BIT;
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data->last_throttled = value;
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if (new_uv == old_uv)
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return;
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if (new_uv)
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dev_crit(data->hwmon_dev, "Undervoltage detected!\n");
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else
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dev_info(data->hwmon_dev, "Voltage normalised\n");
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sysfs_notify(&data->hwmon_dev->kobj, NULL, "in0_lcrit_alarm");
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}
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static void get_values_poll(struct work_struct *work)
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{
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struct rpi_hwmon_data *data;
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data = container_of(work, struct rpi_hwmon_data,
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get_values_poll_work.work);
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rpi_firmware_get_throttled(data);
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/*
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* We can't run faster than the sticky shift (100ms) since we get
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* flipping in the sticky bits that are cleared.
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*/
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schedule_delayed_work(&data->get_values_poll_work, 2 * HZ);
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}
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static int rpi_read(struct device *dev, enum hwmon_sensor_types type,
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u32 attr, int channel, long *val)
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{
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struct rpi_hwmon_data *data = dev_get_drvdata(dev);
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*val = !!(data->last_throttled & UNDERVOLTAGE_STICKY_BIT);
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return 0;
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}
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static umode_t rpi_is_visible(const void *_data, enum hwmon_sensor_types type,
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u32 attr, int channel)
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{
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return 0444;
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}
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static const struct hwmon_channel_info *rpi_info[] = {
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HWMON_CHANNEL_INFO(in,
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HWMON_I_LCRIT_ALARM),
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NULL
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};
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static const struct hwmon_ops rpi_hwmon_ops = {
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.is_visible = rpi_is_visible,
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.read = rpi_read,
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};
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static const struct hwmon_chip_info rpi_chip_info = {
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.ops = &rpi_hwmon_ops,
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.info = rpi_info,
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};
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static int rpi_hwmon_probe(struct platform_device *pdev)
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{
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struct device *dev = &pdev->dev;
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struct rpi_hwmon_data *data;
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data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
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if (!data)
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return -ENOMEM;
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/* Parent driver assure that firmware is correct */
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data->fw = dev_get_drvdata(dev->parent);
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data->hwmon_dev = devm_hwmon_device_register_with_info(dev, "rpi_volt",
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data,
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&rpi_chip_info,
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NULL);
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INIT_DELAYED_WORK(&data->get_values_poll_work, get_values_poll);
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platform_set_drvdata(pdev, data);
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if (!PTR_ERR_OR_ZERO(data->hwmon_dev))
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schedule_delayed_work(&data->get_values_poll_work, 2 * HZ);
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return PTR_ERR_OR_ZERO(data->hwmon_dev);
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}
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static int rpi_hwmon_remove(struct platform_device *pdev)
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{
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struct rpi_hwmon_data *data = platform_get_drvdata(pdev);
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cancel_delayed_work_sync(&data->get_values_poll_work);
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return 0;
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}
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static struct platform_driver rpi_hwmon_driver = {
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.probe = rpi_hwmon_probe,
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.remove = rpi_hwmon_remove,
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.driver = {
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.name = "raspberrypi-hwmon",
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},
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};
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module_platform_driver(rpi_hwmon_driver);
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MODULE_AUTHOR("Stefan Wahren <stefan.wahren@i2se.com>");
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MODULE_DESCRIPTION("Raspberry Pi voltage sensor driver");
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MODULE_LICENSE("GPL v2");
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MODULE_ALIAS("platform:raspberrypi-hwmon");
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