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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-19 10:09:22 -0700 |
| commit | f4cdf7ca9a1fdcca413157df19753f388a5a224e (patch) | |
| tree | 60a31895b2446cd7fa27514e8c2843534a0de0da /drivers/hwmon/lm70.c | |
| download | linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.tar.gz linux-stable-f4cdf7ca9a1fdcca413157df19753f388a5a224e.zip | |
Merge tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-mediagrafted
Pull media updates from Mauro Carvalho Chehab:
- v4l2-core: added ISP statistics support and per-block validation
- v4l2-core: Allow unknown HDR10 white point and luminance
- New camera sensors: Sony IMX678 and IMX471m, Himax HM1092 IR sensor
- New codec: Milos: VPU v2.0 codec support
- isp driver: gained support for Dreamchip RPPX1 ISP framework
- vsp1 driver: gained support for RZ/T2H and RZ/N2H
- Novalake driver: gained CVS support for new NVL hardware
- dvb-core: fix feed leak on failed DMX_ADD_PID
- several driver fixes, cleanups and minor improvements
* tag 'media/v7.3-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (308 commits)
media: ipu-bridge: check all DMI entries when overriding sensor rotation
media: v4l2-async: avoid deleting unlinked ASC entry on link error
media: rzg2l-cru: Align bytesperline to hardware DMA stride requirement
media: intel/ipu6: fix async notifier cleanup leak on parse error
media: staging/ipu7: fix async notifier UAF on probe error path
media: amd: isp4: fix self-deadlock in isp4sd_pwron_and_init() error path
media: amd: isp4: release partial allocations in isp4if_alloc_fw_gpumem()
media: rcar-isp: Fix VSPX reference leaks
media: rcar-isp: Release ISPCORE resources
media: i2c: imx415: Release runtime PM reference on VBLANK error
media: i2c: imx415: Return test pattern write errors
media: renesas: vsp1: Declare index variables in for loop statement
media: renesas: vsp1: Make reset control optional to support platforms without a reset line
media: dt-bindings: media: renesas,vsp1: Document RZ/T2H and RZ/N2H SoCs
media: dt-bindings: media: renesas,fcp: Document RZ/T2H and RZ/N2H SoCs
media: nxp: imx8-isi: Add additional 32-bit RGB format support
media: nxp: imx8-isi: Add 16-bit raw Bayer format support
media: nxp: imx8-isi: Implement per-stream reference counting for multiplexed streams
media: nxp: imx8-isi: Use BIT_ULL() for 64-bit stream masks
media: nxp: imx8-isi: Correct color map between V4L2 and ISI
...
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"); |
