aboutsummaryrefslogtreecommitdiff
path: root/drivers/hwmon/sht21.c
diff options
context:
space:
mode:
authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /drivers/hwmon/sht21.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
linux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.zip
Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
Diffstat (limited to 'drivers/hwmon/sht21.c')
-rw-r--r--drivers/hwmon/sht21.c296
1 files changed, 296 insertions, 0 deletions
diff --git a/drivers/hwmon/sht21.c b/drivers/hwmon/sht21.c
new file mode 100644
index 000000000..e23dbf287
--- /dev/null
+++ b/drivers/hwmon/sht21.c
@@ -0,0 +1,296 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* Sensirion SHT21 humidity and temperature sensor driver
+ *
+ * Copyright (C) 2010 Urs Fleisch <urs.fleisch@sensirion.com>
+ *
+ * Data sheet available at https://www.sensirion.com/file/datasheet_sht21
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/hwmon.h>
+#include <linux/hwmon-sysfs.h>
+#include <linux/err.h>
+#include <linux/mutex.h>
+#include <linux/device.h>
+#include <linux/jiffies.h>
+
+/* I2C command bytes */
+#define SHT21_TRIG_T_MEASUREMENT_HM 0xe3
+#define SHT21_TRIG_RH_MEASUREMENT_HM 0xe5
+#define SHT21_READ_SNB_CMD1 0xFA
+#define SHT21_READ_SNB_CMD2 0x0F
+#define SHT21_READ_SNAC_CMD1 0xFC
+#define SHT21_READ_SNAC_CMD2 0xC9
+
+/**
+ * struct sht21 - SHT21 device specific data
+ * @client: I2C client device
+ * @lock: mutex to protect measurement values
+ * @last_update: time of last update (jiffies)
+ * @temperature: cached temperature measurement value
+ * @humidity: cached humidity measurement value
+ * @valid: only 0 before first measurement is taken
+ * @eic: cached electronic identification code text
+ */
+struct sht21 {
+ struct i2c_client *client;
+ struct mutex lock;
+ unsigned long last_update;
+ int temperature;
+ int humidity;
+ bool valid;
+ char eic[18];
+};
+
+/**
+ * sht21_temp_ticks_to_millicelsius() - convert raw temperature ticks to
+ * milli celsius
+ * @ticks: temperature ticks value received from sensor
+ */
+static inline int sht21_temp_ticks_to_millicelsius(int ticks)
+{
+ ticks &= ~0x0003; /* clear status bits */
+ /*
+ * Formula T = -46.85 + 175.72 * ST / 2^16 from data sheet 6.2,
+ * optimized for integer fixed point (3 digits) arithmetic
+ */
+ return ((21965 * ticks) >> 13) - 46850;
+}
+
+/**
+ * sht21_rh_ticks_to_per_cent_mille() - convert raw humidity ticks to
+ * one-thousandths of a percent relative humidity
+ * @ticks: humidity ticks value received from sensor
+ */
+static inline int sht21_rh_ticks_to_per_cent_mille(int ticks)
+{
+ ticks &= ~0x0003; /* clear status bits */
+ /*
+ * Formula RH = -6 + 125 * SRH / 2^16 from data sheet 6.1,
+ * optimized for integer fixed point (3 digits) arithmetic
+ */
+ return ((15625 * ticks) >> 13) - 6000;
+}
+
+/**
+ * sht21_update_measurements() - get updated measurements from device
+ * @dev: device
+ *
+ * Returns 0 on success, else negative errno.
+ */
+static int sht21_update_measurements(struct device *dev)
+{
+ int ret = 0;
+ struct sht21 *sht21 = dev_get_drvdata(dev);
+ struct i2c_client *client = sht21->client;
+
+ mutex_lock(&sht21->lock);
+ /*
+ * Data sheet 2.4:
+ * SHT2x should not be active for more than 10% of the time - e.g.
+ * maximum two measurements per second at 12bit accuracy shall be made.
+ */
+ if (time_after(jiffies, sht21->last_update + HZ / 2) || !sht21->valid) {
+ ret = i2c_smbus_read_word_swapped(client,
+ SHT21_TRIG_T_MEASUREMENT_HM);
+ if (ret < 0)
+ goto out;
+ sht21->temperature = sht21_temp_ticks_to_millicelsius(ret);
+ ret = i2c_smbus_read_word_swapped(client,
+ SHT21_TRIG_RH_MEASUREMENT_HM);
+ if (ret < 0)
+ goto out;
+ sht21->humidity = sht21_rh_ticks_to_per_cent_mille(ret);
+ sht21->last_update = jiffies;
+ sht21->valid = true;
+ }
+out:
+ mutex_unlock(&sht21->lock);
+
+ return ret >= 0 ? 0 : ret;
+}
+
+/**
+ * sht21_show_temperature() - show temperature measurement value in sysfs
+ * @dev: device
+ * @attr: device attribute
+ * @buf: sysfs buffer (PAGE_SIZE) where measurement values are written to
+ *
+ * Will be called on read access to temp1_input sysfs attribute.
+ * Returns number of bytes written into buffer, negative errno on error.
+ */
+static ssize_t sht21_temperature_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct sht21 *sht21 = dev_get_drvdata(dev);
+ int ret;
+
+ ret = sht21_update_measurements(dev);
+ if (ret < 0)
+ return ret;
+ return sprintf(buf, "%d\n", sht21->temperature);
+}
+
+/**
+ * sht21_show_humidity() - show humidity measurement value in sysfs
+ * @dev: device
+ * @attr: device attribute
+ * @buf: sysfs buffer (PAGE_SIZE) where measurement values are written to
+ *
+ * Will be called on read access to humidity1_input sysfs attribute.
+ * Returns number of bytes written into buffer, negative errno on error.
+ */
+static ssize_t sht21_humidity_show(struct device *dev,
+ struct device_attribute *attr, char *buf)
+{
+ struct sht21 *sht21 = dev_get_drvdata(dev);
+ int ret;
+
+ ret = sht21_update_measurements(dev);
+ if (ret < 0)
+ return ret;
+ return sprintf(buf, "%d\n", sht21->humidity);
+}
+
+static ssize_t eic_read(struct sht21 *sht21)
+{
+ struct i2c_client *client = sht21->client;
+ u8 tx[2];
+ u8 rx[8];
+ u8 eic[8];
+ struct i2c_msg msgs[2] = {
+ {
+ .addr = client->addr,
+ .flags = 0,
+ .len = 2,
+ .buf = tx,
+ },
+ {
+ .addr = client->addr,
+ .flags = I2C_M_RD,
+ .len = 8,
+ .buf = rx,
+ },
+ };
+ int ret;
+
+ tx[0] = SHT21_READ_SNB_CMD1;
+ tx[1] = SHT21_READ_SNB_CMD2;
+ ret = i2c_transfer(client->adapter, msgs, 2);
+ if (ret < 0)
+ goto out;
+ eic[2] = rx[0];
+ eic[3] = rx[2];
+ eic[4] = rx[4];
+ eic[5] = rx[6];
+
+ tx[0] = SHT21_READ_SNAC_CMD1;
+ tx[1] = SHT21_READ_SNAC_CMD2;
+ msgs[1].len = 6;
+ ret = i2c_transfer(client->adapter, msgs, 2);
+ if (ret < 0)
+ goto out;
+ eic[0] = rx[3];
+ eic[1] = rx[4];
+ eic[6] = rx[0];
+ eic[7] = rx[1];
+
+ ret = snprintf(sht21->eic, sizeof(sht21->eic),
+ "%02x%02x%02x%02x%02x%02x%02x%02x\n",
+ eic[0], eic[1], eic[2], eic[3],
+ eic[4], eic[5], eic[6], eic[7]);
+out:
+ if (ret < 0)
+ sht21->eic[0] = 0;
+
+ return ret;
+}
+
+/**
+ * eic_show() - show Electronic Identification Code in sysfs
+ * @dev: device
+ * @attr: device attribute
+ * @buf: sysfs buffer (PAGE_SIZE) where EIC is written
+ *
+ * Will be called on read access to eic sysfs attribute.
+ * Returns number of bytes written into buffer, negative errno on error.
+ */
+static ssize_t eic_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct sht21 *sht21 = dev_get_drvdata(dev);
+ int ret;
+
+ ret = sizeof(sht21->eic) - 1;
+ mutex_lock(&sht21->lock);
+ if (!sht21->eic[0])
+ ret = eic_read(sht21);
+ if (ret > 0)
+ memcpy(buf, sht21->eic, ret);
+ mutex_unlock(&sht21->lock);
+ return ret;
+}
+
+/* sysfs attributes */
+static SENSOR_DEVICE_ATTR_RO(temp1_input, sht21_temperature, 0);
+static SENSOR_DEVICE_ATTR_RO(humidity1_input, sht21_humidity, 0);
+static DEVICE_ATTR_RO(eic);
+
+static struct attribute *sht21_attrs[] = {
+ &sensor_dev_attr_temp1_input.dev_attr.attr,
+ &sensor_dev_attr_humidity1_input.dev_attr.attr,
+ &dev_attr_eic.attr,
+ NULL
+};
+
+ATTRIBUTE_GROUPS(sht21);
+
+static int sht21_probe(struct i2c_client *client)
+{
+ struct device *dev = &client->dev;
+ struct device *hwmon_dev;
+ struct sht21 *sht21;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_WORD_DATA)) {
+ dev_err(&client->dev,
+ "adapter does not support SMBus word transactions\n");
+ return -ENODEV;
+ }
+
+ sht21 = devm_kzalloc(dev, sizeof(*sht21), GFP_KERNEL);
+ if (!sht21)
+ return -ENOMEM;
+
+ sht21->client = client;
+
+ mutex_init(&sht21->lock);
+
+ hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
+ sht21, sht21_groups);
+ return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+/* Device ID table */
+static const struct i2c_device_id sht21_id[] = {
+ { "sht21", 0 },
+ { }
+};
+MODULE_DEVICE_TABLE(i2c, sht21_id);
+
+static struct i2c_driver sht21_driver = {
+ .driver.name = "sht21",
+ .probe_new = sht21_probe,
+ .id_table = sht21_id,
+};
+
+module_i2c_driver(sht21_driver);
+
+MODULE_AUTHOR("Urs Fleisch <urs.fleisch@sensirion.com>");
+MODULE_DESCRIPTION("Sensirion SHT21 humidity and temperature sensor driver");
+MODULE_LICENSE("GPL");