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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/iio/adc/max9611.c
downloadlinux-5b7c4cabbb65f5c469464da6c5f614cbd7f730f2.tar.gz
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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/iio/adc/max9611.c')
-rw-r--r--drivers/iio/adc/max9611.c565
1 files changed, 565 insertions, 0 deletions
diff --git a/drivers/iio/adc/max9611.c b/drivers/iio/adc/max9611.c
new file mode 100644
index 000000000..cb7f47854
--- /dev/null
+++ b/drivers/iio/adc/max9611.c
@@ -0,0 +1,565 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * iio/adc/max9611.c
+ *
+ * Maxim max9611/max9612 high side current sense amplifier with
+ * 12-bit ADC interface.
+ *
+ * Copyright (C) 2017 Jacopo Mondi
+ */
+
+/*
+ * This driver supports input common-mode voltage, current-sense
+ * amplifier with programmable gains and die temperature reading from
+ * Maxim max9611/max9612.
+ *
+ * Op-amp, analog comparator, and watchdog functionalities are not
+ * supported by this driver.
+ */
+
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/property.h>
+
+#define DRIVER_NAME "max9611"
+
+/* max9611 register addresses */
+#define MAX9611_REG_CSA_DATA 0x00
+#define MAX9611_REG_RS_DATA 0x02
+#define MAX9611_REG_TEMP_DATA 0x08
+#define MAX9611_REG_CTRL1 0x0a
+#define MAX9611_REG_CTRL2 0x0b
+
+/* max9611 REG1 mux configuration options */
+#define MAX9611_MUX_MASK GENMASK(3, 0)
+#define MAX9611_MUX_SENSE_1x 0x00
+#define MAX9611_MUX_SENSE_4x 0x01
+#define MAX9611_MUX_SENSE_8x 0x02
+#define MAX9611_INPUT_VOLT 0x03
+#define MAX9611_MUX_TEMP 0x06
+
+/* max9611 voltage (both csa and input) helper macros */
+#define MAX9611_VOLTAGE_SHIFT 0x04
+#define MAX9611_VOLTAGE_RAW(_r) ((_r) >> MAX9611_VOLTAGE_SHIFT)
+
+/*
+ * max9611 current sense amplifier voltage output:
+ * LSB and offset values depends on selected gain (1x, 4x, 8x)
+ *
+ * GAIN LSB (nV) OFFSET (LSB steps)
+ * 1x 107500 1
+ * 4x 26880 1
+ * 8x 13440 3
+ *
+ * The complete formula to calculate current sense voltage is:
+ * (((adc_read >> 4) - offset) / ((1 / LSB) * 10^-3)
+ */
+#define MAX9611_CSA_1X_LSB_nV 107500
+#define MAX9611_CSA_4X_LSB_nV 26880
+#define MAX9611_CSA_8X_LSB_nV 13440
+
+#define MAX9611_CSA_1X_OFFS_RAW 1
+#define MAX9611_CSA_4X_OFFS_RAW 1
+#define MAX9611_CSA_8X_OFFS_RAW 3
+
+/*
+ * max9611 common input mode (CIM): LSB is 14mV, with 14mV offset at 25 C
+ *
+ * The complete formula to calculate input common voltage is:
+ * (((adc_read >> 4) * 1000) - offset) / (1 / 14 * 1000)
+ */
+#define MAX9611_CIM_LSB_mV 14
+#define MAX9611_CIM_OFFSET_RAW 1
+
+/*
+ * max9611 temperature reading: LSB is 480 milli degrees Celsius
+ *
+ * The complete formula to calculate temperature is:
+ * ((adc_read >> 7) * 1000) / (1 / 480 * 1000)
+ */
+#define MAX9611_TEMP_MAX_POS 0x7f80
+#define MAX9611_TEMP_MAX_NEG 0xff80
+#define MAX9611_TEMP_MIN_NEG 0xd980
+#define MAX9611_TEMP_MASK GENMASK(15, 7)
+#define MAX9611_TEMP_SHIFT 0x07
+#define MAX9611_TEMP_RAW(_r) ((_r) >> MAX9611_TEMP_SHIFT)
+#define MAX9611_TEMP_SCALE_NUM 1000000
+#define MAX9611_TEMP_SCALE_DIV 2083
+
+/*
+ * Conversion time is 2 ms (typically) at Ta=25 degreeC
+ * No maximum value is known, so play it safe.
+ */
+#define MAX9611_CONV_TIME_US_RANGE 3000, 3300
+
+struct max9611_dev {
+ struct device *dev;
+ struct i2c_client *i2c_client;
+ struct mutex lock;
+ unsigned int shunt_resistor_uohm;
+};
+
+enum max9611_conf_ids {
+ CONF_SENSE_1x,
+ CONF_SENSE_4x,
+ CONF_SENSE_8x,
+ CONF_IN_VOLT,
+ CONF_TEMP,
+};
+
+/*
+ * max9611_mux_conf - associate ADC mux configuration with register address
+ * where data shall be read from
+ */
+static const unsigned int max9611_mux_conf[][2] = {
+ [CONF_SENSE_1x] = { MAX9611_MUX_SENSE_1x, MAX9611_REG_CSA_DATA },
+ [CONF_SENSE_4x] = { MAX9611_MUX_SENSE_4x, MAX9611_REG_CSA_DATA },
+ [CONF_SENSE_8x] = { MAX9611_MUX_SENSE_8x, MAX9611_REG_CSA_DATA },
+ [CONF_IN_VOLT] = { MAX9611_INPUT_VOLT, MAX9611_REG_RS_DATA },
+ [CONF_TEMP] = { MAX9611_MUX_TEMP, MAX9611_REG_TEMP_DATA },
+};
+
+enum max9611_csa_gain {
+ CSA_GAIN_1x = CONF_SENSE_1x,
+ CSA_GAIN_4x = CONF_SENSE_4x,
+ CSA_GAIN_8x = CONF_SENSE_8x,
+};
+
+enum max9611_csa_gain_params {
+ CSA_GAIN_LSB_nV,
+ CSA_GAIN_OFFS_RAW,
+};
+
+/*
+ * max9611_csa_gain_conf - associate gain multiplier with LSB and
+ * offset values.
+ *
+ * Group together parameters associated with configurable gain
+ * on current sense amplifier path to ADC interface.
+ * Current sense read routine adjusts gain until it gets a meaningful
+ * value; use this structure to retrieve the correct LSB and offset values.
+ */
+static const unsigned int max9611_gain_conf[][2] = {
+ [CSA_GAIN_1x] = { MAX9611_CSA_1X_LSB_nV, MAX9611_CSA_1X_OFFS_RAW, },
+ [CSA_GAIN_4x] = { MAX9611_CSA_4X_LSB_nV, MAX9611_CSA_4X_OFFS_RAW, },
+ [CSA_GAIN_8x] = { MAX9611_CSA_8X_LSB_nV, MAX9611_CSA_8X_OFFS_RAW, },
+};
+
+enum max9611_chan_addrs {
+ MAX9611_CHAN_VOLTAGE_INPUT,
+ MAX9611_CHAN_VOLTAGE_SENSE,
+ MAX9611_CHAN_TEMPERATURE,
+ MAX9611_CHAN_CURRENT_LOAD,
+ MAX9611_CHAN_POWER_LOAD,
+};
+
+static const struct iio_chan_spec max9611_channels[] = {
+ {
+ .type = IIO_TEMP,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE),
+ .address = MAX9611_CHAN_TEMPERATURE,
+ },
+ {
+ .type = IIO_VOLTAGE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .address = MAX9611_CHAN_VOLTAGE_SENSE,
+ .indexed = 1,
+ .channel = 0,
+ },
+ {
+ .type = IIO_VOLTAGE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |
+ BIT(IIO_CHAN_INFO_SCALE) |
+ BIT(IIO_CHAN_INFO_OFFSET),
+ .address = MAX9611_CHAN_VOLTAGE_INPUT,
+ .indexed = 1,
+ .channel = 1,
+ },
+ {
+ .type = IIO_CURRENT,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .address = MAX9611_CHAN_CURRENT_LOAD,
+ },
+ {
+ .type = IIO_POWER,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ .address = MAX9611_CHAN_POWER_LOAD
+ },
+};
+
+/**
+ * max9611_read_single() - read a single value from ADC interface
+ *
+ * Data registers are 16 bit long, spread between two 8 bit registers
+ * with consecutive addresses.
+ * Configure ADC mux first, then read register at address "reg_addr".
+ * The smbus_read_word routine asks for 16 bits and the ADC is kind enough
+ * to return values from "reg_addr" and "reg_addr + 1" consecutively.
+ * Data are transmitted with big-endian ordering: MSB arrives first.
+ *
+ * @max9611: max9611 device
+ * @selector: index for mux and register configuration
+ * @raw_val: the value returned from ADC
+ */
+static int max9611_read_single(struct max9611_dev *max9611,
+ enum max9611_conf_ids selector,
+ u16 *raw_val)
+{
+ int ret;
+
+ u8 mux_conf = max9611_mux_conf[selector][0] & MAX9611_MUX_MASK;
+ u8 reg_addr = max9611_mux_conf[selector][1];
+
+ /*
+ * Keep mutex lock held during read-write to avoid mux register
+ * (CTRL1) re-configuration.
+ */
+ mutex_lock(&max9611->lock);
+ ret = i2c_smbus_write_byte_data(max9611->i2c_client,
+ MAX9611_REG_CTRL1, mux_conf);
+ if (ret) {
+ dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n",
+ MAX9611_REG_CTRL1, mux_conf);
+ mutex_unlock(&max9611->lock);
+ return ret;
+ }
+
+ /* need a delay here to make register configuration stabilize. */
+
+ usleep_range(MAX9611_CONV_TIME_US_RANGE);
+
+ ret = i2c_smbus_read_word_swapped(max9611->i2c_client, reg_addr);
+ if (ret < 0) {
+ dev_err(max9611->dev, "i2c read word from 0x%2x failed\n",
+ reg_addr);
+ mutex_unlock(&max9611->lock);
+ return ret;
+ }
+
+ *raw_val = ret;
+ mutex_unlock(&max9611->lock);
+
+ return 0;
+}
+
+/**
+ * max9611_read_csa_voltage() - read current sense amplifier output voltage
+ *
+ * Current sense amplifier output voltage is read through a configurable
+ * 1x, 4x or 8x gain.
+ * Start with plain 1x gain, and adjust gain control properly until a
+ * meaningful value is read from ADC output.
+ *
+ * @max9611: max9611 device
+ * @adc_raw: raw value read from ADC output
+ * @csa_gain: gain configuration option selector
+ */
+static int max9611_read_csa_voltage(struct max9611_dev *max9611,
+ u16 *adc_raw,
+ enum max9611_csa_gain *csa_gain)
+{
+ enum max9611_conf_ids gain_selectors[] = {
+ CONF_SENSE_1x,
+ CONF_SENSE_4x,
+ CONF_SENSE_8x
+ };
+ unsigned int i;
+ int ret;
+
+ for (i = 0; i < ARRAY_SIZE(gain_selectors); ++i) {
+ ret = max9611_read_single(max9611, gain_selectors[i], adc_raw);
+ if (ret)
+ return ret;
+
+ if (*adc_raw > 0) {
+ *csa_gain = (enum max9611_csa_gain)gain_selectors[i];
+ return 0;
+ }
+ }
+
+ return -EIO;
+}
+
+static int max9611_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long mask)
+{
+ struct max9611_dev *dev = iio_priv(indio_dev);
+ enum max9611_csa_gain gain_selector;
+ const unsigned int *csa_gain;
+ u16 adc_data;
+ int ret;
+
+ switch (mask) {
+ case IIO_CHAN_INFO_RAW:
+
+ switch (chan->address) {
+ case MAX9611_CHAN_TEMPERATURE:
+ ret = max9611_read_single(dev, CONF_TEMP,
+ &adc_data);
+ if (ret)
+ return -EINVAL;
+
+ *val = MAX9611_TEMP_RAW(adc_data);
+ return IIO_VAL_INT;
+
+ case MAX9611_CHAN_VOLTAGE_INPUT:
+ ret = max9611_read_single(dev, CONF_IN_VOLT,
+ &adc_data);
+ if (ret)
+ return -EINVAL;
+
+ *val = MAX9611_VOLTAGE_RAW(adc_data);
+ return IIO_VAL_INT;
+ }
+
+ break;
+
+ case IIO_CHAN_INFO_OFFSET:
+ /* MAX9611_CHAN_VOLTAGE_INPUT */
+ *val = MAX9611_CIM_OFFSET_RAW;
+
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+
+ switch (chan->address) {
+ case MAX9611_CHAN_TEMPERATURE:
+ *val = MAX9611_TEMP_SCALE_NUM;
+ *val2 = MAX9611_TEMP_SCALE_DIV;
+
+ return IIO_VAL_FRACTIONAL;
+
+ case MAX9611_CHAN_VOLTAGE_INPUT:
+ *val = MAX9611_CIM_LSB_mV;
+
+ return IIO_VAL_INT;
+ }
+
+ break;
+
+ case IIO_CHAN_INFO_PROCESSED:
+
+ switch (chan->address) {
+ case MAX9611_CHAN_VOLTAGE_SENSE:
+ /*
+ * processed (mV): (raw - offset) * LSB (nV) / 10^6
+ *
+ * Even if max9611 can output raw csa voltage readings,
+ * use a produced value as scale depends on gain.
+ */
+ ret = max9611_read_csa_voltage(dev, &adc_data,
+ &gain_selector);
+ if (ret)
+ return -EINVAL;
+
+ csa_gain = max9611_gain_conf[gain_selector];
+
+ adc_data -= csa_gain[CSA_GAIN_OFFS_RAW];
+ *val = MAX9611_VOLTAGE_RAW(adc_data) *
+ csa_gain[CSA_GAIN_LSB_nV];
+ *val2 = 1000000;
+
+ return IIO_VAL_FRACTIONAL;
+
+ case MAX9611_CHAN_CURRENT_LOAD:
+ /* processed (mA): Vcsa (nV) / Rshunt (uOhm) */
+ ret = max9611_read_csa_voltage(dev, &adc_data,
+ &gain_selector);
+ if (ret)
+ return -EINVAL;
+
+ csa_gain = max9611_gain_conf[gain_selector];
+
+ adc_data -= csa_gain[CSA_GAIN_OFFS_RAW];
+ *val = MAX9611_VOLTAGE_RAW(adc_data) *
+ csa_gain[CSA_GAIN_LSB_nV];
+ *val2 = dev->shunt_resistor_uohm;
+
+ return IIO_VAL_FRACTIONAL;
+
+ case MAX9611_CHAN_POWER_LOAD:
+ /*
+ * processed (mW): Vin (mV) * Vcsa (uV) /
+ * Rshunt (uOhm)
+ */
+ ret = max9611_read_single(dev, CONF_IN_VOLT,
+ &adc_data);
+ if (ret)
+ return -EINVAL;
+
+ adc_data -= MAX9611_CIM_OFFSET_RAW;
+ *val = MAX9611_VOLTAGE_RAW(adc_data) *
+ MAX9611_CIM_LSB_mV;
+
+ ret = max9611_read_csa_voltage(dev, &adc_data,
+ &gain_selector);
+ if (ret)
+ return -EINVAL;
+
+ csa_gain = max9611_gain_conf[gain_selector];
+
+ /* divide by 10^3 here to avoid 32bit overflow */
+ adc_data -= csa_gain[CSA_GAIN_OFFS_RAW];
+ *val *= MAX9611_VOLTAGE_RAW(adc_data) *
+ csa_gain[CSA_GAIN_LSB_nV] / 1000;
+ *val2 = dev->shunt_resistor_uohm;
+
+ return IIO_VAL_FRACTIONAL;
+ }
+
+ break;
+ }
+
+ return -EINVAL;
+}
+
+static ssize_t max9611_shunt_resistor_show(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct max9611_dev *max9611 = iio_priv(dev_to_iio_dev(dev));
+ unsigned int i, r;
+
+ i = max9611->shunt_resistor_uohm / 1000000;
+ r = max9611->shunt_resistor_uohm % 1000000;
+
+ return sysfs_emit(buf, "%u.%06u\n", i, r);
+}
+
+static IIO_DEVICE_ATTR(in_power_shunt_resistor, 0444,
+ max9611_shunt_resistor_show, NULL, 0);
+static IIO_DEVICE_ATTR(in_current_shunt_resistor, 0444,
+ max9611_shunt_resistor_show, NULL, 0);
+
+static struct attribute *max9611_attributes[] = {
+ &iio_dev_attr_in_power_shunt_resistor.dev_attr.attr,
+ &iio_dev_attr_in_current_shunt_resistor.dev_attr.attr,
+ NULL,
+};
+
+static const struct attribute_group max9611_attribute_group = {
+ .attrs = max9611_attributes,
+};
+
+static const struct iio_info indio_info = {
+ .read_raw = max9611_read_raw,
+ .attrs = &max9611_attribute_group,
+};
+
+static int max9611_init(struct max9611_dev *max9611)
+{
+ struct i2c_client *client = max9611->i2c_client;
+ u16 regval;
+ int ret;
+
+ if (!i2c_check_functionality(client->adapter,
+ I2C_FUNC_SMBUS_WRITE_BYTE |
+ I2C_FUNC_SMBUS_READ_WORD_DATA)) {
+ dev_err(max9611->dev,
+ "I2c adapter does not support smbus write_byte or read_word functionalities: aborting probe.\n");
+ return -EINVAL;
+ }
+
+ /* Make sure die temperature is in range to test communications. */
+ ret = max9611_read_single(max9611, CONF_TEMP, &regval);
+ if (ret)
+ return ret;
+
+ regval &= MAX9611_TEMP_MASK;
+
+ if ((regval > MAX9611_TEMP_MAX_POS &&
+ regval < MAX9611_TEMP_MIN_NEG) ||
+ regval > MAX9611_TEMP_MAX_NEG) {
+ dev_err(max9611->dev,
+ "Invalid value received from ADC 0x%4x: aborting\n",
+ regval);
+ return -EIO;
+ }
+
+ /* Mux shall be zeroed back before applying other configurations */
+ ret = i2c_smbus_write_byte_data(max9611->i2c_client,
+ MAX9611_REG_CTRL1, 0);
+ if (ret) {
+ dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n",
+ MAX9611_REG_CTRL1, 0);
+ return ret;
+ }
+
+ ret = i2c_smbus_write_byte_data(max9611->i2c_client,
+ MAX9611_REG_CTRL2, 0);
+ if (ret) {
+ dev_err(max9611->dev, "i2c write byte failed: 0x%2x - 0x%2x\n",
+ MAX9611_REG_CTRL2, 0);
+ return ret;
+ }
+ usleep_range(MAX9611_CONV_TIME_US_RANGE);
+
+ return 0;
+}
+
+static const struct of_device_id max9611_of_table[] = {
+ {.compatible = "maxim,max9611", .data = "max9611"},
+ {.compatible = "maxim,max9612", .data = "max9612"},
+ { },
+};
+
+MODULE_DEVICE_TABLE(of, max9611_of_table);
+static int max9611_probe(struct i2c_client *client)
+{
+ const char * const shunt_res_prop = "shunt-resistor-micro-ohms";
+ struct max9611_dev *max9611;
+ struct iio_dev *indio_dev;
+ struct device *dev = &client->dev;
+ unsigned int of_shunt;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*max9611));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ i2c_set_clientdata(client, indio_dev);
+
+ max9611 = iio_priv(indio_dev);
+ max9611->dev = dev;
+ max9611->i2c_client = client;
+ mutex_init(&max9611->lock);
+
+ ret = device_property_read_u32(dev, shunt_res_prop, &of_shunt);
+ if (ret) {
+ dev_err(dev, "Missing %s property for %pfw node\n",
+ shunt_res_prop, dev_fwnode(dev));
+ return ret;
+ }
+ max9611->shunt_resistor_uohm = of_shunt;
+
+ ret = max9611_init(max9611);
+ if (ret)
+ return ret;
+
+ indio_dev->name = device_get_match_data(dev);
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &indio_info;
+ indio_dev->channels = max9611_channels;
+ indio_dev->num_channels = ARRAY_SIZE(max9611_channels);
+
+ return devm_iio_device_register(dev, indio_dev);
+}
+
+static struct i2c_driver max9611_driver = {
+ .driver = {
+ .name = DRIVER_NAME,
+ .of_match_table = max9611_of_table,
+ },
+ .probe_new = max9611_probe,
+};
+module_i2c_driver(max9611_driver);
+
+MODULE_AUTHOR("Jacopo Mondi <jacopo+renesas@jmondi.org>");
+MODULE_DESCRIPTION("Maxim max9611/12 current sense amplifier with 12bit ADC");
+MODULE_LICENSE("GPL v2");