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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/hwmon/max197.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/hwmon/max197.c')
| -rw-r--r-- | drivers/hwmon/max197.c | 341 |
1 files changed, 341 insertions, 0 deletions
diff --git a/drivers/hwmon/max197.c b/drivers/hwmon/max197.c new file mode 100644 index 000000000..0d315087b --- /dev/null +++ b/drivers/hwmon/max197.c @@ -0,0 +1,341 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Maxim MAX197 A/D Converter driver + * + * Copyright (c) 2012 Savoir-faire Linux Inc. + * Vivien Didelot <vivien.didelot@savoirfairelinux.com> + * + * For further information, see the Documentation/hwmon/max197.rst file. + */ + +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/mutex.h> +#include <linux/device.h> +#include <linux/sysfs.h> +#include <linux/hwmon.h> +#include <linux/hwmon-sysfs.h> +#include <linux/platform_device.h> +#include <linux/platform_data/max197.h> + +#define MAX199_LIMIT 4000 /* 4V */ +#define MAX197_LIMIT 10000 /* 10V */ + +#define MAX197_NUM_CH 8 /* 8 Analog Input Channels */ + +/* Control byte format */ +#define MAX197_BIP (1 << 3) /* Bipolarity */ +#define MAX197_RNG (1 << 4) /* Full range */ + +#define MAX197_SCALE 12207 /* Scale coefficient for raw data */ + +/* List of supported chips */ +enum max197_chips { max197, max199 }; + +/** + * struct max197_data - device instance specific data + * @pdata: Platform data. + * @hwmon_dev: The hwmon device. + * @lock: Read/Write mutex. + * @limit: Max range value (10V for MAX197, 4V for MAX199). + * @scale: Need to scale. + * @ctrl_bytes: Channels control byte. + */ +struct max197_data { + struct max197_platform_data *pdata; + struct device *hwmon_dev; + struct mutex lock; + int limit; + bool scale; + u8 ctrl_bytes[MAX197_NUM_CH]; +}; + +static inline void max197_set_unipolarity(struct max197_data *data, int channel) +{ + data->ctrl_bytes[channel] &= ~MAX197_BIP; +} + +static inline void max197_set_bipolarity(struct max197_data *data, int channel) +{ + data->ctrl_bytes[channel] |= MAX197_BIP; +} + +static inline void max197_set_half_range(struct max197_data *data, int channel) +{ + data->ctrl_bytes[channel] &= ~MAX197_RNG; +} + +static inline void max197_set_full_range(struct max197_data *data, int channel) +{ + data->ctrl_bytes[channel] |= MAX197_RNG; +} + +static inline bool max197_is_bipolar(struct max197_data *data, int channel) +{ + return data->ctrl_bytes[channel] & MAX197_BIP; +} + +static inline bool max197_is_full_range(struct max197_data *data, int channel) +{ + return data->ctrl_bytes[channel] & MAX197_RNG; +} + +/* Function called on read access on in{0,1,2,3,4,5,6,7}_{min,max} */ +static ssize_t max197_show_range(struct device *dev, + struct device_attribute *devattr, char *buf) +{ + struct max197_data *data = dev_get_drvdata(dev); + struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr); + int channel = attr->index; + bool is_min = attr->nr; + int range; + + if (mutex_lock_interruptible(&data->lock)) + return -ERESTARTSYS; + + range = max197_is_full_range(data, channel) ? + data->limit : data->limit / 2; + if (is_min) { + if (max197_is_bipolar(data, channel)) + range = -range; + else + range = 0; + } + + mutex_unlock(&data->lock); + + return sprintf(buf, "%d\n", range); +} + +/* Function called on write access on in{0,1,2,3,4,5,6,7}_{min,max} */ +static ssize_t max197_store_range(struct device *dev, + struct device_attribute *devattr, + const char *buf, size_t count) +{ + struct max197_data *data = dev_get_drvdata(dev); + struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(devattr); + int channel = attr->index; + bool is_min = attr->nr; + long value; + int half = data->limit / 2; + int full = data->limit; + + if (kstrtol(buf, 10, &value)) + return -EINVAL; + + if (is_min) { + if (value <= -full) + value = -full; + else if (value < 0) + value = -half; + else + value = 0; + } else { + if (value >= full) + value = full; + else + value = half; + } + + if (mutex_lock_interruptible(&data->lock)) + return -ERESTARTSYS; + + if (value == 0) { + /* We can deduce only the polarity */ + max197_set_unipolarity(data, channel); + } else if (value == -half) { + max197_set_bipolarity(data, channel); + max197_set_half_range(data, channel); + } else if (value == -full) { + max197_set_bipolarity(data, channel); + max197_set_full_range(data, channel); + } else if (value == half) { + /* We can deduce only the range */ + max197_set_half_range(data, channel); + } else if (value == full) { + /* We can deduce only the range */ + max197_set_full_range(data, channel); + } + + mutex_unlock(&data->lock); + + return count; +} + +/* Function called on read access on in{0,1,2,3,4,5,6,7}_input */ +static ssize_t max197_show_input(struct device *dev, + struct device_attribute *devattr, + char *buf) +{ + struct max197_data *data = dev_get_drvdata(dev); + struct sensor_device_attribute *attr = to_sensor_dev_attr(devattr); + int channel = attr->index; + s32 value; + int ret; + + if (mutex_lock_interruptible(&data->lock)) + return -ERESTARTSYS; + + ret = data->pdata->convert(data->ctrl_bytes[channel]); + if (ret < 0) { + dev_err(dev, "conversion failed\n"); + goto unlock; + } + value = ret; + + /* + * Coefficient to apply on raw value. + * See Table 1. Full Scale and Zero Scale in the MAX197 datasheet. + */ + if (data->scale) { + value *= MAX197_SCALE; + if (max197_is_full_range(data, channel)) + value *= 2; + value /= 10000; + } + + ret = sprintf(buf, "%d\n", value); + +unlock: + mutex_unlock(&data->lock); + return ret; +} + +static ssize_t name_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct platform_device *pdev = to_platform_device(dev); + return sprintf(buf, "%s\n", pdev->name); +} + +#define MAX197_SENSOR_DEVICE_ATTR_CH(chan) \ + static SENSOR_DEVICE_ATTR(in##chan##_input, S_IRUGO, \ + max197_show_input, NULL, chan); \ + static SENSOR_DEVICE_ATTR_2(in##chan##_min, S_IRUGO | S_IWUSR, \ + max197_show_range, \ + max197_store_range, \ + true, chan); \ + static SENSOR_DEVICE_ATTR_2(in##chan##_max, S_IRUGO | S_IWUSR, \ + max197_show_range, \ + max197_store_range, \ + false, chan) + +#define MAX197_SENSOR_DEV_ATTR_IN(chan) \ + &sensor_dev_attr_in##chan##_input.dev_attr.attr, \ + &sensor_dev_attr_in##chan##_max.dev_attr.attr, \ + &sensor_dev_attr_in##chan##_min.dev_attr.attr + +static DEVICE_ATTR_RO(name); + +MAX197_SENSOR_DEVICE_ATTR_CH(0); +MAX197_SENSOR_DEVICE_ATTR_CH(1); +MAX197_SENSOR_DEVICE_ATTR_CH(2); +MAX197_SENSOR_DEVICE_ATTR_CH(3); +MAX197_SENSOR_DEVICE_ATTR_CH(4); +MAX197_SENSOR_DEVICE_ATTR_CH(5); +MAX197_SENSOR_DEVICE_ATTR_CH(6); +MAX197_SENSOR_DEVICE_ATTR_CH(7); + +static const struct attribute_group max197_sysfs_group = { + .attrs = (struct attribute *[]) { + &dev_attr_name.attr, + MAX197_SENSOR_DEV_ATTR_IN(0), + MAX197_SENSOR_DEV_ATTR_IN(1), + MAX197_SENSOR_DEV_ATTR_IN(2), + MAX197_SENSOR_DEV_ATTR_IN(3), + MAX197_SENSOR_DEV_ATTR_IN(4), + MAX197_SENSOR_DEV_ATTR_IN(5), + MAX197_SENSOR_DEV_ATTR_IN(6), + MAX197_SENSOR_DEV_ATTR_IN(7), + NULL + }, +}; + +static int max197_probe(struct platform_device *pdev) +{ + int ch, ret; + struct max197_data *data; + struct max197_platform_data *pdata = dev_get_platdata(&pdev->dev); + enum max197_chips chip = platform_get_device_id(pdev)->driver_data; + + if (pdata == NULL) { + dev_err(&pdev->dev, "no platform data supplied\n"); + return -EINVAL; + } + + if (pdata->convert == NULL) { + dev_err(&pdev->dev, "no convert function supplied\n"); + return -EINVAL; + } + + data = devm_kzalloc(&pdev->dev, sizeof(struct max197_data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->pdata = pdata; + mutex_init(&data->lock); + + if (chip == max197) { + data->limit = MAX197_LIMIT; + data->scale = true; + } else { + data->limit = MAX199_LIMIT; + data->scale = false; + } + + for (ch = 0; ch < MAX197_NUM_CH; ch++) + data->ctrl_bytes[ch] = (u8) ch; + + platform_set_drvdata(pdev, data); + + ret = sysfs_create_group(&pdev->dev.kobj, &max197_sysfs_group); + if (ret) { + dev_err(&pdev->dev, "sysfs create group failed\n"); + return ret; + } + + data->hwmon_dev = hwmon_device_register(&pdev->dev); + if (IS_ERR(data->hwmon_dev)) { + ret = PTR_ERR(data->hwmon_dev); + dev_err(&pdev->dev, "hwmon device register failed\n"); + goto error; + } + + return 0; + +error: + sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group); + return ret; +} + +static void max197_remove(struct platform_device *pdev) +{ + struct max197_data *data = platform_get_drvdata(pdev); + + hwmon_device_unregister(data->hwmon_dev); + sysfs_remove_group(&pdev->dev.kobj, &max197_sysfs_group); +} + +static const struct platform_device_id max197_device_ids[] = { + { .name = "max197", .driver_data = max197 }, + { .name = "max199", .driver_data = max199 }, + { } +}; +MODULE_DEVICE_TABLE(platform, max197_device_ids); + +static struct platform_driver max197_driver = { + .driver = { + .name = "max197", + }, + .probe = max197_probe, + .remove = max197_remove, + .id_table = max197_device_ids, +}; +module_platform_driver(max197_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Savoir-faire Linux Inc. <kernel@savoirfairelinux.com>"); +MODULE_DESCRIPTION("Maxim MAX197 A/D Converter driver"); |
