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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/lm70.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/lm70.c')
| -rw-r--r-- | drivers/hwmon/lm70.c | 217 |
1 files changed, 217 insertions, 0 deletions
diff --git a/drivers/hwmon/lm70.c b/drivers/hwmon/lm70.c new file mode 100644 index 000000000..8b525725f --- /dev/null +++ b/drivers/hwmon/lm70.c @@ -0,0 +1,217 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * lm70.c + * + * The LM70 is a temperature sensor chip from National Semiconductor (NS). + * Copyright (C) 2006 Kaiwan N Billimoria <kaiwan@designergraphix.com> + * + * The LM70 communicates with a host processor via an SPI/Microwire Bus + * interface. The complete datasheet is available at TI's website + * here: + * https://www.ti.com/product/LM70 + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/init.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/sysfs.h> +#include <linux/hwmon.h> +#include <linux/mutex.h> +#include <linux/of.h> +#include <linux/property.h> +#include <linux/spi/spi.h> +#include <linux/slab.h> + +#define DRVNAME "lm70" + +#define LM70_CHIP_LM70 0 /* original NS LM70 */ +#define LM70_CHIP_TMP121 1 /* TI TMP121/TMP123 */ +#define LM70_CHIP_LM71 2 /* NS LM71 */ +#define LM70_CHIP_LM74 3 /* NS LM74 */ +#define LM70_CHIP_TMP122 4 /* TI TMP122/TMP124 */ +#define LM70_CHIP_TMP125 5 /* TI TMP125 */ + +struct lm70 { + struct spi_device *spi; + struct mutex lock; + unsigned int chip; +}; + +/* sysfs hook function */ +static ssize_t temp1_input_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct lm70 *p_lm70 = dev_get_drvdata(dev); + struct spi_device *spi = p_lm70->spi; + int status, val = 0; + u8 rxbuf[2]; + s16 raw = 0; + + if (mutex_lock_interruptible(&p_lm70->lock)) + return -ERESTARTSYS; + + /* + * spi_read() requires a DMA-safe buffer; so we use + * spi_write_then_read(), transmitting 0 bytes. + */ + status = spi_write_then_read(spi, NULL, 0, &rxbuf[0], 2); + if (status < 0) { + dev_warn(dev, "spi_write_then_read failed with status %d\n", + status); + goto out; + } + raw = (rxbuf[0] << 8) + rxbuf[1]; + dev_dbg(dev, "rxbuf[0] : 0x%02x rxbuf[1] : 0x%02x raw=0x%04x\n", + rxbuf[0], rxbuf[1], raw); + + /* + * LM70: + * The "raw" temperature read into rxbuf[] is a 16-bit signed 2's + * complement value. Only the MSB 11 bits (1 sign + 10 temperature + * bits) are meaningful; the LSB 5 bits are to be discarded. + * See the datasheet. + * + * Further, each bit represents 0.25 degrees Celsius; so, multiply + * by 0.25. Also multiply by 1000 to represent in millidegrees + * Celsius. + * So it's equivalent to multiplying by 0.25 * 1000 = 250. + * + * LM74 and TMP121/TMP122/TMP123/TMP124: + * 13 bits of 2's complement data, discard LSB 3 bits, + * resolution 0.0625 degrees celsius. + * + * LM71: + * 14 bits of 2's complement data, discard LSB 2 bits, + * resolution 0.0312 degrees celsius. + * + * TMP125: + * MSB/D15 is a leading zero. D14 is the sign-bit. This is + * followed by 9 temperature bits (D13..D5) in 2's complement + * data format with a resolution of 0.25 degrees celsius per unit. + * LSB 5 bits (D4..D0) share the same value as D5 and get discarded. + */ + switch (p_lm70->chip) { + case LM70_CHIP_LM70: + val = ((int)raw / 32) * 250; + break; + + case LM70_CHIP_TMP121: + case LM70_CHIP_TMP122: + case LM70_CHIP_LM74: + val = ((int)raw / 8) * 625 / 10; + break; + + case LM70_CHIP_LM71: + val = ((int)raw / 4) * 3125 / 100; + break; + + case LM70_CHIP_TMP125: + val = (sign_extend32(raw, 14) / 32) * 250; + break; + } + + status = sprintf(buf, "%d\n", val); /* millidegrees Celsius */ +out: + mutex_unlock(&p_lm70->lock); + return status; +} + +static DEVICE_ATTR_RO(temp1_input); + +static struct attribute *lm70_attrs[] = { + &dev_attr_temp1_input.attr, + NULL +}; + +ATTRIBUTE_GROUPS(lm70); + +/*----------------------------------------------------------------------*/ + +#ifdef CONFIG_OF +static const struct of_device_id lm70_of_ids[] = { + { + .compatible = "ti,lm70", + .data = (void *) LM70_CHIP_LM70, + }, + { + .compatible = "ti,tmp121", + .data = (void *) LM70_CHIP_TMP121, + }, + { + .compatible = "ti,tmp122", + .data = (void *) LM70_CHIP_TMP122, + }, + { + .compatible = "ti,tmp125", + .data = (void *) LM70_CHIP_TMP125, + }, + { + .compatible = "ti,lm71", + .data = (void *) LM70_CHIP_LM71, + }, + { + .compatible = "ti,lm74", + .data = (void *) LM70_CHIP_LM74, + }, + {}, +}; +MODULE_DEVICE_TABLE(of, lm70_of_ids); +#endif + +static int lm70_probe(struct spi_device *spi) +{ + struct device *hwmon_dev; + struct lm70 *p_lm70; + int chip; + + chip = (kernel_ulong_t)spi_get_device_match_data(spi); + + /* signaling is SPI_MODE_0 */ + if ((spi->mode & SPI_MODE_X_MASK) != SPI_MODE_0) + return -EINVAL; + + /* NOTE: we assume 8-bit words, and convert to 16 bits manually */ + + p_lm70 = devm_kzalloc(&spi->dev, sizeof(*p_lm70), GFP_KERNEL); + if (!p_lm70) + return -ENOMEM; + + mutex_init(&p_lm70->lock); + p_lm70->chip = chip; + p_lm70->spi = spi; + + hwmon_dev = devm_hwmon_device_register_with_groups(&spi->dev, + spi->modalias, + p_lm70, lm70_groups); + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static const struct spi_device_id lm70_ids[] = { + { "lm70", LM70_CHIP_LM70 }, + { "tmp121", LM70_CHIP_TMP121 }, + { "tmp122", LM70_CHIP_TMP122 }, + { "tmp125", LM70_CHIP_TMP125 }, + { "lm71", LM70_CHIP_LM71 }, + { "lm74", LM70_CHIP_LM74 }, + { }, +}; +MODULE_DEVICE_TABLE(spi, lm70_ids); + +static struct spi_driver lm70_driver = { + .driver = { + .name = "lm70", + .of_match_table = of_match_ptr(lm70_of_ids), + }, + .id_table = lm70_ids, + .probe = lm70_probe, +}; + +module_spi_driver(lm70_driver); + +MODULE_AUTHOR("Kaiwan N Billimoria"); +MODULE_DESCRIPTION("NS LM70 and compatibles Linux driver"); +MODULE_LICENSE("GPL"); |
