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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/ad7768-1.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/ad7768-1.c')
-rw-r--r--drivers/iio/adc/ad7768-1.c677
1 files changed, 677 insertions, 0 deletions
diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c
new file mode 100644
index 000000000..70a259491
--- /dev/null
+++ b/drivers/iio/adc/ad7768-1.c
@@ -0,0 +1,677 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Analog Devices AD7768-1 SPI ADC driver
+ *
+ * Copyright 2017 Analog Devices Inc.
+ */
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/gpio/consumer.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/regulator/consumer.h>
+#include <linux/sysfs.h>
+#include <linux/spi/spi.h>
+
+#include <linux/iio/buffer.h>
+#include <linux/iio/iio.h>
+#include <linux/iio/sysfs.h>
+#include <linux/iio/trigger.h>
+#include <linux/iio/triggered_buffer.h>
+#include <linux/iio/trigger_consumer.h>
+
+/* AD7768 registers definition */
+#define AD7768_REG_CHIP_TYPE 0x3
+#define AD7768_REG_PROD_ID_L 0x4
+#define AD7768_REG_PROD_ID_H 0x5
+#define AD7768_REG_CHIP_GRADE 0x6
+#define AD7768_REG_SCRATCH_PAD 0x0A
+#define AD7768_REG_VENDOR_L 0x0C
+#define AD7768_REG_VENDOR_H 0x0D
+#define AD7768_REG_INTERFACE_FORMAT 0x14
+#define AD7768_REG_POWER_CLOCK 0x15
+#define AD7768_REG_ANALOG 0x16
+#define AD7768_REG_ANALOG2 0x17
+#define AD7768_REG_CONVERSION 0x18
+#define AD7768_REG_DIGITAL_FILTER 0x19
+#define AD7768_REG_SINC3_DEC_RATE_MSB 0x1A
+#define AD7768_REG_SINC3_DEC_RATE_LSB 0x1B
+#define AD7768_REG_DUTY_CYCLE_RATIO 0x1C
+#define AD7768_REG_SYNC_RESET 0x1D
+#define AD7768_REG_GPIO_CONTROL 0x1E
+#define AD7768_REG_GPIO_WRITE 0x1F
+#define AD7768_REG_GPIO_READ 0x20
+#define AD7768_REG_OFFSET_HI 0x21
+#define AD7768_REG_OFFSET_MID 0x22
+#define AD7768_REG_OFFSET_LO 0x23
+#define AD7768_REG_GAIN_HI 0x24
+#define AD7768_REG_GAIN_MID 0x25
+#define AD7768_REG_GAIN_LO 0x26
+#define AD7768_REG_SPI_DIAG_ENABLE 0x28
+#define AD7768_REG_ADC_DIAG_ENABLE 0x29
+#define AD7768_REG_DIG_DIAG_ENABLE 0x2A
+#define AD7768_REG_ADC_DATA 0x2C
+#define AD7768_REG_MASTER_STATUS 0x2D
+#define AD7768_REG_SPI_DIAG_STATUS 0x2E
+#define AD7768_REG_ADC_DIAG_STATUS 0x2F
+#define AD7768_REG_DIG_DIAG_STATUS 0x30
+#define AD7768_REG_MCLK_COUNTER 0x31
+
+/* AD7768_REG_POWER_CLOCK */
+#define AD7768_PWR_MCLK_DIV_MSK GENMASK(5, 4)
+#define AD7768_PWR_MCLK_DIV(x) FIELD_PREP(AD7768_PWR_MCLK_DIV_MSK, x)
+#define AD7768_PWR_PWRMODE_MSK GENMASK(1, 0)
+#define AD7768_PWR_PWRMODE(x) FIELD_PREP(AD7768_PWR_PWRMODE_MSK, x)
+
+/* AD7768_REG_DIGITAL_FILTER */
+#define AD7768_DIG_FIL_FIL_MSK GENMASK(6, 4)
+#define AD7768_DIG_FIL_FIL(x) FIELD_PREP(AD7768_DIG_FIL_FIL_MSK, x)
+#define AD7768_DIG_FIL_DEC_MSK GENMASK(2, 0)
+#define AD7768_DIG_FIL_DEC_RATE(x) FIELD_PREP(AD7768_DIG_FIL_DEC_MSK, x)
+
+/* AD7768_REG_CONVERSION */
+#define AD7768_CONV_MODE_MSK GENMASK(2, 0)
+#define AD7768_CONV_MODE(x) FIELD_PREP(AD7768_CONV_MODE_MSK, x)
+
+#define AD7768_RD_FLAG_MSK(x) (BIT(6) | ((x) & 0x3F))
+#define AD7768_WR_FLAG_MSK(x) ((x) & 0x3F)
+
+enum ad7768_conv_mode {
+ AD7768_CONTINUOUS,
+ AD7768_ONE_SHOT,
+ AD7768_SINGLE,
+ AD7768_PERIODIC,
+ AD7768_STANDBY
+};
+
+enum ad7768_pwrmode {
+ AD7768_ECO_MODE = 0,
+ AD7768_MED_MODE = 2,
+ AD7768_FAST_MODE = 3
+};
+
+enum ad7768_mclk_div {
+ AD7768_MCLK_DIV_16,
+ AD7768_MCLK_DIV_8,
+ AD7768_MCLK_DIV_4,
+ AD7768_MCLK_DIV_2
+};
+
+enum ad7768_dec_rate {
+ AD7768_DEC_RATE_32 = 0,
+ AD7768_DEC_RATE_64 = 1,
+ AD7768_DEC_RATE_128 = 2,
+ AD7768_DEC_RATE_256 = 3,
+ AD7768_DEC_RATE_512 = 4,
+ AD7768_DEC_RATE_1024 = 5,
+ AD7768_DEC_RATE_8 = 9,
+ AD7768_DEC_RATE_16 = 10
+};
+
+struct ad7768_clk_configuration {
+ enum ad7768_mclk_div mclk_div;
+ enum ad7768_dec_rate dec_rate;
+ unsigned int clk_div;
+ enum ad7768_pwrmode pwrmode;
+};
+
+static const struct ad7768_clk_configuration ad7768_clk_config[] = {
+ { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_8, 16, AD7768_FAST_MODE },
+ { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_16, 32, AD7768_FAST_MODE },
+ { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_32, 64, AD7768_FAST_MODE },
+ { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_64, 128, AD7768_FAST_MODE },
+ { AD7768_MCLK_DIV_2, AD7768_DEC_RATE_128, 256, AD7768_FAST_MODE },
+ { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_128, 512, AD7768_MED_MODE },
+ { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_256, 1024, AD7768_MED_MODE },
+ { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_512, 2048, AD7768_MED_MODE },
+ { AD7768_MCLK_DIV_4, AD7768_DEC_RATE_1024, 4096, AD7768_MED_MODE },
+ { AD7768_MCLK_DIV_8, AD7768_DEC_RATE_1024, 8192, AD7768_MED_MODE },
+ { AD7768_MCLK_DIV_16, AD7768_DEC_RATE_1024, 16384, AD7768_ECO_MODE },
+};
+
+static const struct iio_chan_spec ad7768_channels[] = {
+ {
+ .type = IIO_VOLTAGE,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
+ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),
+ .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ),
+ .indexed = 1,
+ .channel = 0,
+ .scan_index = 0,
+ .scan_type = {
+ .sign = 'u',
+ .realbits = 24,
+ .storagebits = 32,
+ .shift = 8,
+ .endianness = IIO_BE,
+ },
+ },
+};
+
+struct ad7768_state {
+ struct spi_device *spi;
+ struct regulator *vref;
+ struct mutex lock;
+ struct clk *mclk;
+ unsigned int mclk_freq;
+ unsigned int samp_freq;
+ struct completion completion;
+ struct iio_trigger *trig;
+ struct gpio_desc *gpio_sync_in;
+ const char *labels[ARRAY_SIZE(ad7768_channels)];
+ /*
+ * DMA (thus cache coherency maintenance) may require the
+ * transfer buffers to live in their own cache lines.
+ */
+ union {
+ struct {
+ __be32 chan;
+ s64 timestamp;
+ } scan;
+ __be32 d32;
+ u8 d8[2];
+ } data __aligned(IIO_DMA_MINALIGN);
+};
+
+static int ad7768_spi_reg_read(struct ad7768_state *st, unsigned int addr,
+ unsigned int len)
+{
+ unsigned int shift;
+ int ret;
+
+ shift = 32 - (8 * len);
+ st->data.d8[0] = AD7768_RD_FLAG_MSK(addr);
+
+ ret = spi_write_then_read(st->spi, st->data.d8, 1,
+ &st->data.d32, len);
+ if (ret < 0)
+ return ret;
+
+ return (be32_to_cpu(st->data.d32) >> shift);
+}
+
+static int ad7768_spi_reg_write(struct ad7768_state *st,
+ unsigned int addr,
+ unsigned int val)
+{
+ st->data.d8[0] = AD7768_WR_FLAG_MSK(addr);
+ st->data.d8[1] = val & 0xFF;
+
+ return spi_write(st->spi, st->data.d8, 2);
+}
+
+static int ad7768_set_mode(struct ad7768_state *st,
+ enum ad7768_conv_mode mode)
+{
+ int regval;
+
+ regval = ad7768_spi_reg_read(st, AD7768_REG_CONVERSION, 1);
+ if (regval < 0)
+ return regval;
+
+ regval &= ~AD7768_CONV_MODE_MSK;
+ regval |= AD7768_CONV_MODE(mode);
+
+ return ad7768_spi_reg_write(st, AD7768_REG_CONVERSION, regval);
+}
+
+static int ad7768_scan_direct(struct iio_dev *indio_dev)
+{
+ struct ad7768_state *st = iio_priv(indio_dev);
+ int readval, ret;
+
+ reinit_completion(&st->completion);
+
+ ret = ad7768_set_mode(st, AD7768_ONE_SHOT);
+ if (ret < 0)
+ return ret;
+
+ ret = wait_for_completion_timeout(&st->completion,
+ msecs_to_jiffies(1000));
+ if (!ret)
+ return -ETIMEDOUT;
+
+ readval = ad7768_spi_reg_read(st, AD7768_REG_ADC_DATA, 3);
+ if (readval < 0)
+ return readval;
+ /*
+ * Any SPI configuration of the AD7768-1 can only be
+ * performed in continuous conversion mode.
+ */
+ ret = ad7768_set_mode(st, AD7768_CONTINUOUS);
+ if (ret < 0)
+ return ret;
+
+ return readval;
+}
+
+static int ad7768_reg_access(struct iio_dev *indio_dev,
+ unsigned int reg,
+ unsigned int writeval,
+ unsigned int *readval)
+{
+ struct ad7768_state *st = iio_priv(indio_dev);
+ int ret;
+
+ mutex_lock(&st->lock);
+ if (readval) {
+ ret = ad7768_spi_reg_read(st, reg, 1);
+ if (ret < 0)
+ goto err_unlock;
+ *readval = ret;
+ ret = 0;
+ } else {
+ ret = ad7768_spi_reg_write(st, reg, writeval);
+ }
+err_unlock:
+ mutex_unlock(&st->lock);
+
+ return ret;
+}
+
+static int ad7768_set_dig_fil(struct ad7768_state *st,
+ enum ad7768_dec_rate dec_rate)
+{
+ unsigned int mode;
+ int ret;
+
+ if (dec_rate == AD7768_DEC_RATE_8 || dec_rate == AD7768_DEC_RATE_16)
+ mode = AD7768_DIG_FIL_FIL(dec_rate);
+ else
+ mode = AD7768_DIG_FIL_DEC_RATE(dec_rate);
+
+ ret = ad7768_spi_reg_write(st, AD7768_REG_DIGITAL_FILTER, mode);
+ if (ret < 0)
+ return ret;
+
+ /* A sync-in pulse is required every time the filter dec rate changes */
+ gpiod_set_value(st->gpio_sync_in, 1);
+ gpiod_set_value(st->gpio_sync_in, 0);
+
+ return 0;
+}
+
+static int ad7768_set_freq(struct ad7768_state *st,
+ unsigned int freq)
+{
+ unsigned int diff_new, diff_old, pwr_mode, i, idx;
+ int res, ret;
+
+ diff_old = U32_MAX;
+ idx = 0;
+
+ res = DIV_ROUND_CLOSEST(st->mclk_freq, freq);
+
+ /* Find the closest match for the desired sampling frequency */
+ for (i = 0; i < ARRAY_SIZE(ad7768_clk_config); i++) {
+ diff_new = abs(res - ad7768_clk_config[i].clk_div);
+ if (diff_new < diff_old) {
+ diff_old = diff_new;
+ idx = i;
+ }
+ }
+
+ /*
+ * Set both the mclk_div and pwrmode with a single write to the
+ * POWER_CLOCK register
+ */
+ pwr_mode = AD7768_PWR_MCLK_DIV(ad7768_clk_config[idx].mclk_div) |
+ AD7768_PWR_PWRMODE(ad7768_clk_config[idx].pwrmode);
+ ret = ad7768_spi_reg_write(st, AD7768_REG_POWER_CLOCK, pwr_mode);
+ if (ret < 0)
+ return ret;
+
+ ret = ad7768_set_dig_fil(st, ad7768_clk_config[idx].dec_rate);
+ if (ret < 0)
+ return ret;
+
+ st->samp_freq = DIV_ROUND_CLOSEST(st->mclk_freq,
+ ad7768_clk_config[idx].clk_div);
+
+ return 0;
+}
+
+static ssize_t ad7768_sampling_freq_avail(struct device *dev,
+ struct device_attribute *attr,
+ char *buf)
+{
+ struct iio_dev *indio_dev = dev_to_iio_dev(dev);
+ struct ad7768_state *st = iio_priv(indio_dev);
+ unsigned int freq;
+ int i, len = 0;
+
+ for (i = 0; i < ARRAY_SIZE(ad7768_clk_config); i++) {
+ freq = DIV_ROUND_CLOSEST(st->mclk_freq,
+ ad7768_clk_config[i].clk_div);
+ len += scnprintf(buf + len, PAGE_SIZE - len, "%d ", freq);
+ }
+
+ buf[len - 1] = '\n';
+
+ return len;
+}
+
+static IIO_DEV_ATTR_SAMP_FREQ_AVAIL(ad7768_sampling_freq_avail);
+
+static int ad7768_read_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int *val, int *val2, long info)
+{
+ struct ad7768_state *st = iio_priv(indio_dev);
+ int scale_uv, ret;
+
+ switch (info) {
+ case IIO_CHAN_INFO_RAW:
+ ret = iio_device_claim_direct_mode(indio_dev);
+ if (ret)
+ return ret;
+
+ ret = ad7768_scan_direct(indio_dev);
+ if (ret >= 0)
+ *val = ret;
+
+ iio_device_release_direct_mode(indio_dev);
+ if (ret < 0)
+ return ret;
+
+ return IIO_VAL_INT;
+
+ case IIO_CHAN_INFO_SCALE:
+ scale_uv = regulator_get_voltage(st->vref);
+ if (scale_uv < 0)
+ return scale_uv;
+
+ *val = (scale_uv * 2) / 1000;
+ *val2 = chan->scan_type.realbits;
+
+ return IIO_VAL_FRACTIONAL_LOG2;
+
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ *val = st->samp_freq;
+
+ return IIO_VAL_INT;
+ }
+
+ return -EINVAL;
+}
+
+static int ad7768_write_raw(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan,
+ int val, int val2, long info)
+{
+ struct ad7768_state *st = iio_priv(indio_dev);
+
+ switch (info) {
+ case IIO_CHAN_INFO_SAMP_FREQ:
+ return ad7768_set_freq(st, val);
+ default:
+ return -EINVAL;
+ }
+}
+
+static int ad7768_read_label(struct iio_dev *indio_dev,
+ const struct iio_chan_spec *chan, char *label)
+{
+ struct ad7768_state *st = iio_priv(indio_dev);
+
+ return sprintf(label, "%s\n", st->labels[chan->channel]);
+}
+
+static struct attribute *ad7768_attributes[] = {
+ &iio_dev_attr_sampling_frequency_available.dev_attr.attr,
+ NULL
+};
+
+static const struct attribute_group ad7768_group = {
+ .attrs = ad7768_attributes,
+};
+
+static const struct iio_info ad7768_info = {
+ .attrs = &ad7768_group,
+ .read_raw = &ad7768_read_raw,
+ .write_raw = &ad7768_write_raw,
+ .read_label = ad7768_read_label,
+ .debugfs_reg_access = &ad7768_reg_access,
+};
+
+static int ad7768_setup(struct ad7768_state *st)
+{
+ int ret;
+
+ /*
+ * Two writes to the SPI_RESET[1:0] bits are required to initiate
+ * a software reset. The bits must first be set to 11, and then
+ * to 10. When the sequence is detected, the reset occurs.
+ * See the datasheet, page 70.
+ */
+ ret = ad7768_spi_reg_write(st, AD7768_REG_SYNC_RESET, 0x3);
+ if (ret)
+ return ret;
+
+ ret = ad7768_spi_reg_write(st, AD7768_REG_SYNC_RESET, 0x2);
+ if (ret)
+ return ret;
+
+ st->gpio_sync_in = devm_gpiod_get(&st->spi->dev, "adi,sync-in",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(st->gpio_sync_in))
+ return PTR_ERR(st->gpio_sync_in);
+
+ /* Set the default sampling frequency to 32000 kSPS */
+ return ad7768_set_freq(st, 32000);
+}
+
+static irqreturn_t ad7768_trigger_handler(int irq, void *p)
+{
+ struct iio_poll_func *pf = p;
+ struct iio_dev *indio_dev = pf->indio_dev;
+ struct ad7768_state *st = iio_priv(indio_dev);
+ int ret;
+
+ mutex_lock(&st->lock);
+
+ ret = spi_read(st->spi, &st->data.scan.chan, 3);
+ if (ret < 0)
+ goto err_unlock;
+
+ iio_push_to_buffers_with_timestamp(indio_dev, &st->data.scan,
+ iio_get_time_ns(indio_dev));
+
+err_unlock:
+ iio_trigger_notify_done(indio_dev->trig);
+ mutex_unlock(&st->lock);
+
+ return IRQ_HANDLED;
+}
+
+static irqreturn_t ad7768_interrupt(int irq, void *dev_id)
+{
+ struct iio_dev *indio_dev = dev_id;
+ struct ad7768_state *st = iio_priv(indio_dev);
+
+ if (iio_buffer_enabled(indio_dev))
+ iio_trigger_poll(st->trig);
+ else
+ complete(&st->completion);
+
+ return IRQ_HANDLED;
+};
+
+static int ad7768_buffer_postenable(struct iio_dev *indio_dev)
+{
+ struct ad7768_state *st = iio_priv(indio_dev);
+
+ /*
+ * Write a 1 to the LSB of the INTERFACE_FORMAT register to enter
+ * continuous read mode. Subsequent data reads do not require an
+ * initial 8-bit write to query the ADC_DATA register.
+ */
+ return ad7768_spi_reg_write(st, AD7768_REG_INTERFACE_FORMAT, 0x01);
+}
+
+static int ad7768_buffer_predisable(struct iio_dev *indio_dev)
+{
+ struct ad7768_state *st = iio_priv(indio_dev);
+
+ /*
+ * To exit continuous read mode, perform a single read of the ADC_DATA
+ * reg (0x2C), which allows further configuration of the device.
+ */
+ return ad7768_spi_reg_read(st, AD7768_REG_ADC_DATA, 3);
+}
+
+static const struct iio_buffer_setup_ops ad7768_buffer_ops = {
+ .postenable = &ad7768_buffer_postenable,
+ .predisable = &ad7768_buffer_predisable,
+};
+
+static const struct iio_trigger_ops ad7768_trigger_ops = {
+ .validate_device = iio_trigger_validate_own_device,
+};
+
+static void ad7768_regulator_disable(void *data)
+{
+ struct ad7768_state *st = data;
+
+ regulator_disable(st->vref);
+}
+
+static int ad7768_set_channel_label(struct iio_dev *indio_dev,
+ int num_channels)
+{
+ struct ad7768_state *st = iio_priv(indio_dev);
+ struct device *device = indio_dev->dev.parent;
+ struct fwnode_handle *fwnode;
+ struct fwnode_handle *child;
+ const char *label;
+ int crt_ch = 0;
+
+ fwnode = dev_fwnode(device);
+ fwnode_for_each_child_node(fwnode, child) {
+ if (fwnode_property_read_u32(child, "reg", &crt_ch))
+ continue;
+
+ if (crt_ch >= num_channels)
+ continue;
+
+ if (fwnode_property_read_string(child, "label", &label))
+ continue;
+
+ st->labels[crt_ch] = label;
+ }
+
+ return 0;
+}
+
+static int ad7768_probe(struct spi_device *spi)
+{
+ struct ad7768_state *st;
+ struct iio_dev *indio_dev;
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
+ if (!indio_dev)
+ return -ENOMEM;
+
+ st = iio_priv(indio_dev);
+ st->spi = spi;
+
+ st->vref = devm_regulator_get(&spi->dev, "vref");
+ if (IS_ERR(st->vref))
+ return PTR_ERR(st->vref);
+
+ ret = regulator_enable(st->vref);
+ if (ret) {
+ dev_err(&spi->dev, "Failed to enable specified vref supply\n");
+ return ret;
+ }
+
+ ret = devm_add_action_or_reset(&spi->dev, ad7768_regulator_disable, st);
+ if (ret)
+ return ret;
+
+ st->mclk = devm_clk_get_enabled(&spi->dev, "mclk");
+ if (IS_ERR(st->mclk))
+ return PTR_ERR(st->mclk);
+
+ st->mclk_freq = clk_get_rate(st->mclk);
+
+ mutex_init(&st->lock);
+
+ indio_dev->channels = ad7768_channels;
+ indio_dev->num_channels = ARRAY_SIZE(ad7768_channels);
+ indio_dev->name = spi_get_device_id(spi)->name;
+ indio_dev->info = &ad7768_info;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+
+ ret = ad7768_setup(st);
+ if (ret < 0) {
+ dev_err(&spi->dev, "AD7768 setup failed\n");
+ return ret;
+ }
+
+ st->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d",
+ indio_dev->name,
+ iio_device_id(indio_dev));
+ if (!st->trig)
+ return -ENOMEM;
+
+ st->trig->ops = &ad7768_trigger_ops;
+ iio_trigger_set_drvdata(st->trig, indio_dev);
+ ret = devm_iio_trigger_register(&spi->dev, st->trig);
+ if (ret)
+ return ret;
+
+ indio_dev->trig = iio_trigger_get(st->trig);
+
+ init_completion(&st->completion);
+
+ ret = ad7768_set_channel_label(indio_dev, ARRAY_SIZE(ad7768_channels));
+ if (ret)
+ return ret;
+
+ ret = devm_request_irq(&spi->dev, spi->irq,
+ &ad7768_interrupt,
+ IRQF_TRIGGER_RISING | IRQF_ONESHOT,
+ indio_dev->name, indio_dev);
+ if (ret)
+ return ret;
+
+ ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev,
+ &iio_pollfunc_store_time,
+ &ad7768_trigger_handler,
+ &ad7768_buffer_ops);
+ if (ret)
+ return ret;
+
+ return devm_iio_device_register(&spi->dev, indio_dev);
+}
+
+static const struct spi_device_id ad7768_id_table[] = {
+ { "ad7768-1", 0 },
+ {}
+};
+MODULE_DEVICE_TABLE(spi, ad7768_id_table);
+
+static const struct of_device_id ad7768_of_match[] = {
+ { .compatible = "adi,ad7768-1" },
+ { },
+};
+MODULE_DEVICE_TABLE(of, ad7768_of_match);
+
+static struct spi_driver ad7768_driver = {
+ .driver = {
+ .name = "ad7768-1",
+ .of_match_table = ad7768_of_match,
+ },
+ .probe = ad7768_probe,
+ .id_table = ad7768_id_table,
+};
+module_spi_driver(ad7768_driver);
+
+MODULE_AUTHOR("Stefan Popa <stefan.popa@analog.com>");
+MODULE_DESCRIPTION("Analog Devices AD7768-1 ADC driver");
+MODULE_LICENSE("GPL v2");