[PATCH v7 3/4] hwmon: pmbus: add MPQ8646 driver
Vincent Jardin via B4 Relay <[email protected]>
| Newsgroups | org.kernel.vger.linux-doc,org.kernel.feeds.b4-sent,org.kernel.vger.linux-devicetree,org.kernel.vger.linux-hwmon,org.kernel.vger.linux-kernel |
|---|---|
| Message-ID | <[email protected]> |
From: Vincent Jardin <[email protected]> Add a new driver for the MPS MPQ8646 that is a PMBus device. Beyond basic PMBus telemetry, the driver adds: - alarm acknowledge via inX_reset_history. - STATUS_WORD MPS-extended bit decode and the NVM-backed PROTECTION_LAST post-mortem, exposed as a read-only debugfs decoder. - In-driver alarm-poll fallback work item (thanks lm90) for boards without SMBALERT Signed-off-by: Vincent Jardin <[email protected]> --- Documentation/hwmon/index.rst | 1 + Documentation/hwmon/mpq8646.rst | 261 +++++++++++++++ MAINTAINERS | 7 + drivers/hwmon/pmbus/Kconfig | 11 + drivers/hwmon/pmbus/Makefile | 1 + drivers/hwmon/pmbus/mpq8646.c | 688 ++++++++++++++++++++++++++++++++++++++++ 6 files changed, 969 insertions(+) diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst index 29130df44d12..be52f9f4dc70 100644 --- a/Documentation/hwmon/index.rst +++ b/Documentation/hwmon/index.rst @@ -201,6 +201,7 @@ Hardware Monitoring Kernel Drivers mp5990 mp9941 mp9945 + mpq8646 mpq8785 nct6683 nct6775 diff --git a/Documentation/hwmon/mpq8646.rst b/Documentation/hwmon/mpq8646.rst new file mode 100644 index 000000000000..d3ede656ea15 --- /dev/null +++ b/Documentation/hwmon/mpq8646.rst @@ -0,0 +1,261 @@ +.. SPDX-License-Identifier: GPL-2.0-only +.. Copyright (c) 2026 Free Mobile - Vincent Jardin <[email protected]> + +Kernel driver mpq8646 +===================== + +Supported chips: + + * MPS MPQ8646 + + Prefix: 'mpq8646' + +Author: + - Vincent Jardin <[email protected]> + +Chip-identity +------------- + +Support the boards that are designed with the MPS MPQ8646 probed thanks +to``MFR_MODEL`` register. + +This driver targets the MPQ8646 silicon specifically. + +Description +----------- + +The MPQ8646 is a fully integrated, PMBus-compatible, high-frequency, +synchronous buck converter. It offers a compact solution that +achieves up high Amps output current per phase, with excellent load +and line regulation over a wide input supply range. The chip +operates at high efficiency over a wide output current load range. + +The PMBus interface provides converter configurations and key +parameters monitoring. + +The device adopts MPS's proprietary multi-phase digital +constant-on-time (MCOT) control, which provides fast transient +response and eases loop stabilization. The MCOT scheme also allows +multiple devices or channels to be connected in parallel with +excellent current sharing and phase interleaving for high-current +applications. + +Fully integrated protection features include over-current +protection (OCP), over-voltage protection (OVP), under-voltage +protection (UVP), and over-temperature protection (OTP). + +This device is compliant with: + +- PMBus rev 1.3 interface. + +The driver exports the following attributes via the 'sysfs' files +for input voltage: + +- in1_input +- in1_label +- in1_max +- in1_max_alarm +- in1_min +- in1_min_alarm +- in1_crit +- in1_crit_alarm + +The driver provides the following attributes for output voltage: + +- in2_input +- in2_label +- in2_alarm +- in2_max +- in2_max_alarm +- in2_min +- in2_min_alarm +- in2_crit +- in2_crit_alarm +- in2_lcrit +- in2_lcrit_alarm + +The driver provides the following attributes for output current: + +- curr1_input +- curr1_label +- curr1_max +- curr1_max_alarm +- curr1_crit +- curr1_crit_alarm + +The driver provides the following attributes for temperature: + +- temp1_input +- temp1_max +- temp1_max_alarm +- temp1_crit +- temp1_crit_alarm + +Alarm acknowledgment +--------------------- + +The hwmon-class ``inX_alarm``/``currX_alarm``/``tempX_alarm`` files are +read-only in pmbus_core. The driver exposes the standard +``PMBUS_VIRT_RESET_*_HISTORY`` virtual-register channel for fault +acknowledgment: writing ``1`` to ``inX_reset_history`` / +``currX_reset_history`` / ``tempX_reset_history`` sends the chip a +``CLEAR_FAULTS`` (0x03) Send-Byte, which clears the latched +``STATUS_WORD`` / ``STATUS_VOUT`` / ``STATUS_IOUT`` / +``STATUS_INPUT`` / ``STATUS_TEMPERATURE`` bits the chip is currently +exposing. + +The MPS-specific NVM post-mortem register +``PROTECTION_LAST`` (0xFB) is not cleared by this path; it can be read +(decoded) via the ``protection_last`` debugfs entry described below. + +Regulator framework integration +------------------------------- + +When ``CONFIG_REGULATOR=y`` is set, the chip is +exposed under ``/sys/class/regulator/`` and accepts the standard +regulator framework operations: + +- ``regulator_enable()`` / ``regulator_disable()`` -> ``OPERATION`` (0x01) +- ``regulator_set_voltage()`` -> ``VOUT_COMMAND`` (0x21) +- ``regulator_get_voltage()`` -> ``READ_VOUT`` (0x8B) +- ``regulator_is_enabled()`` -> ``OPERATION`` bit-decode + +The single regulator descriptor is named ``"vout"`` (page 0). For a +multi-page configuration the descriptor table can be extended in +the driver. + +In-driver alarm-poll fallback +----------------------------- + +On boards where the chip's ``SMBALERT#`` pin is unavailable to the +SoC, ``pmbus_core::pmbus_irq_setup`` cannot deliver SMBALERT-driven +``poll(POLLPRI)`` wakes or ``udev change@...`` events on the +``inX_alarm`` files. The driver provides a ``delayed_work``-based +polling fallback that +periodically invokes the pmbus core fault check, +``pmbus_check_and_notify_faults()``, which sends the notifications and +then clears the latched faults, exactly like the ``SMBALERT#`` +interrupt path. The frequency of polling is tunable: + +:: + + /sys/kernel/debug/i2c/i2c-<bus>/<bus>-<addr>/alarm_poll_interval_ms + +The default is 1000 ms. + +Set it to 0 to disable. The worker self-suppresses +when ``client->irq != 0`` (i.e. when DT supplies an +``interrupts = <...>`` property on the regulator node), so adding +``SMBALERT#`` wiring is a zero-driver-change uplift on a future +board rev. + +MPS post-mortem (PROTECTION_LAST) +--------------------------------- + +The MPQ8646 silicon keeps a single 16-bit NVM-backed record of the +last protection event in ``PROTECTION_LAST`` (0xFB). It survives +chip power/reset. The following debugfs entries expose it: + +:: + + /sys/kernel/debug/i2c/i2c-<bus>/<bus>-<addr>/protection_last (RO) + /sys/kernel/debug/i2c/i2c-<bus>/<bus>-<addr>/status_decoded (RO) + +``protection_last`` decodes the 16-bit value based on the datasheet +fault names (``INIT_FAULT``, ``NVM_CRC_ERROR``, ``NVM_FAULT``, +``OC_PHASE_FAULT``, ``OTP_SELF_FAULT``, ``SWITCH_PRD_FAULT``, +``VIN_OV_FAULT``, ``VOUT_OV_FAULT``, ``VOUT_UV_FAULT``, +``OC_TOT_FAULT``, ``VIN_UVLO_FAULT``, ``DRMOS_OTP``). + +``status_decoded`` reads ``STATUS_WORD`` (0x79) and renders the +16 bits with MPS-extension labels (bit12 = ``NVM_SUMMARY``, +bit8 = ``WATCH_DOG``, bit0 = ``DRMOS_FAULT``) instead of the +PMBus 1.3 spec generic names. + +NVMEM snapshot +-------------- + +When ``CONFIG_NVMEM=y`` is set, the chip's NVM-backed +observability registers are exposed as a single 16-byte read-only +``nvmem_device`` at ``/sys/bus/nvmem/devices/<i2c-name>/nvmem``. +Layout (little-endian for 16-bit fields, zero-fill on per-entry read +failure and for the reserved tail): + +:: + + offset 0..1 PROTECTION_LAST (0xFB) word + offset 2..3 MFR_RETRY_TIMES (0xF4) word + offset 4..5 MFR_CONFIG_ID (0xC0) word + offset 6..7 MFR_VBOOT_CFG (0xFC) word + offset 8 MFR_SILICON_REV (0xC3) byte + offset 9..15 reserved (zero) + +Suitable for single-``cat`` post-mortem capture by a fleet daemon. + +Diagnostics and introspection +----------------------------- + +When ``CONFIG_DEBUG_FS=y`` is set, the driver adds a read-only +decode surface to the client's pmbus debugfs directory, +``/sys/kernel/debug/i2c/i2c-<bus>/<bus>-<addr>/``. +The driver intentionally exposes no raw register poke/peek debugfs; +use i2c-dev (``i2cget``/``i2cset``/``i2ctransfer``) for that. + +Identity / observability (read-only): + +========================== ================== ================================= +File PMBus / MFR cmd Description +========================== ================== ================================= +``mfr_config_id`` 0xC0 (word) board / SKU NVM identifier +``mfr_config_code_rev`` 0xC1 (word) NVM image revision (PART_RECOG + + config code rev fields) +``mfr_silicon_rev`` 0xC3 (byte) die revision +``mfr_retry_times`` 0xF4 (word) per-fault-class recovery-mode + configuration (NOT a retry + count). Four 4-bit fields + [15:12]=OTP, [11:8]=VOUT_OV, + [7:4]=VOUT_UV, [3:0]=OCP. + Each field: 0x0=latch-off, + 0x1..0xE=retry N times then + latch off, 0xF=hiccup + (retry indefinitely). The + chip exposes no in-NVM + retry-event counter; track + transitions externally if + needed (poll + ``protection_last`` or watch + ``inX_alarm`` / ``temp1_alarm`` + ``poll(POLLPRI)`` wakes). +``mfr_vboot_cfg`` 0xFC (word) ADDR/VBOOT latched at POR +========================== ================== ================================= + +Timing / UVLO knobs (read-only): + +========================== ================== ================================= +File PMBus cmd Description +========================== ================== ================================= +``vin_on`` 0x35 (word) UVLO turn-on threshold +``vin_off`` 0x36 (word) UVLO turn-off threshold +``ton_delay`` 0x60 (word) soft-start delay +``ton_rise`` 0x61 (word) soft-start ramp time +``toff_delay`` 0x64 (word) soft-stop delay +``toff_fall`` 0x65 (word) soft-stop ramp time +========================== ================== ================================= + +The only writable entry is ``alarm_poll_interval_ms`` (the alarm-poll +worker cadence, see above), it is driver-local and never touches the +chip. + +Devicetree +---------- + +The driver uses ``compatible = "mps,mpq8646"``. There are some few optional +properties: + +- ``mps,vout-fb-divider-ratio-permille`` : it writes ``VOUT_SCALE_LOOP`` + (0x29) at probe to compensate for an external resistor divider in + the VOUT feedback path. The valid range is 11-bit. +- ``interrupts = <...>`` : if the board routes the chip's + ``SMBALERT#`` pin to a SoC GPIO, declaring it here lights up + ``pmbus_core::pmbus_irq_setup`` and disables the in-driver + alarm-poll fallback diff --git a/MAINTAINERS b/MAINTAINERS index 1ab8736850ea..88dc83d98896 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -18328,6 +18328,13 @@ S: Maintained F: Documentation/hwmon/mp9945.rst F: drivers/hwmon/pmbus/mp9945.c +MPS MPQ8646 PMBUS DRIVER +M: Vincent Jardin <[email protected]> +L: [email protected] +S: Maintained +F: Documentation/hwmon/mpq8646.rst +F: drivers/hwmon/pmbus/mpq8646.c + MR800 AVERMEDIA USB FM RADIO DRIVER M: Alexey Klimov <[email protected]> L: [email protected] diff --git a/drivers/hwmon/pmbus/Kconfig b/drivers/hwmon/pmbus/Kconfig index c8cda160b5f8..9f44e76b0b64 100644 --- a/drivers/hwmon/pmbus/Kconfig +++ b/drivers/hwmon/pmbus/Kconfig @@ -616,6 +616,17 @@ config SENSORS_MPQ8785 This driver can also be built as a module. If so, the module will be called mpq8785. +config SENSORS_MPQ8646 + tristate "MPS MPQ8646" + depends on REGULATOR || !REGULATOR + depends on NVMEM || !NVMEM + help + If you say yes here you get hardware monitoring support for the + Monolithic Power Systems MPQ8646. + + This driver can also be built as a module. If so, the module + will be called mpq8646. + config SENSORS_PIM4328 tristate "Flex PIM4328 and compatibles" help diff --git a/drivers/hwmon/pmbus/Makefile b/drivers/hwmon/pmbus/Makefile index ffc05f493213..6f8fda966600 100644 --- a/drivers/hwmon/pmbus/Makefile +++ b/drivers/hwmon/pmbus/Makefile @@ -60,6 +60,7 @@ obj-$(CONFIG_SENSORS_MP9941) += mp9941.o obj-$(CONFIG_SENSORS_MP9945) += mp9945.o obj-$(CONFIG_SENSORS_MPQ7932) += mpq7932.o obj-$(CONFIG_SENSORS_MPQ8785) += mpq8785.o +obj-$(CONFIG_SENSORS_MPQ8646) += mpq8646.o obj-$(CONFIG_SENSORS_PLI1209BC) += pli1209bc.o obj-$(CONFIG_SENSORS_PM6764TR) += pm6764tr.o obj-$(CONFIG_SENSORS_PXE1610) += pxe1610.o diff --git a/drivers/hwmon/pmbus/mpq8646.c b/drivers/hwmon/pmbus/mpq8646.c new file mode 100644 index 000000000000..5133a2471873 --- /dev/null +++ b/drivers/hwmon/pmbus/mpq8646.c @@ -0,0 +1,688 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Driver for MPS MPQ8646 step-down converter. + * + * Copyright (c) 2026 Free Mobile - Vincent Jardin <[email protected]> + */ + +#include <linux/bitops.h> +#include <linux/debugfs.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/nvmem-provider.h> +#include <linux/of_device.h> +#include <linux/pmbus.h> +#include <linux/property.h> +#include <linux/regulator/driver.h> +#include <linux/seq_file.h> +#include <linux/workqueue.h> +#include "pmbus.h" + +/* Default cadence for the in-driver alarm-poll fallback (ms) */ +#define MPQ8646_ALARM_POLL_MS_DEFAULT 1000 + +/* MPS vendor-extended command codes (NOT in PMBus 1.3 Part II) */ +#define MPS_PROTECTION_LAST 0xFB + +/* PMBus 1.3 timing / UVLO command codes */ +#define PMBUS_VIN_ON 0x35 +#define PMBUS_VIN_OFF 0x36 +#define PMBUS_TON_DELAY 0x60 +#define PMBUS_TON_RISE 0x61 +#define PMBUS_TOFF_DELAY 0x64 +#define PMBUS_TOFF_FALL 0x65 + +/* MPS vendor-extended observability / identity registers */ +#define MPS_MFR_CONFIG_ID 0xC0 +#define MPS_MFR_CONFIG_CODE_REV 0xC1 +#define MPS_MFR_SILICON_REV 0xC3 +#define MPS_MFR_RETRY_TIMES 0xF4 +#define MPS_MFR_VBOOT_CFG 0xFC + +#define MPQ8646_DEBUG(client, fmt, ...) \ + dev_dbg(&(client)->dev, fmt, ##__VA_ARGS__) + +/* + * Maximum legal value for VOUT_SCALE_LOOP (0x29) on the MPQ8646 silicon + * The chip uses an 11-bit VOUT feedback-divider scale register. + */ +#define MPQ8646_VOUT_SCALE_LOOP_MAX GENMASK(10, 0) + +/* Forward declaration */ +struct mpq8646_dbg_reg_ctx; + +/* Per-instance state */ +struct mpq8646_priv { + struct pmbus_driver_info info; /* must be first, container_of target */ + struct i2c_client *client; + + /* Serialises CLEAR_LAST_FAULT sequences and PROTECTION_LAST reads */ + struct mutex mps_lock; + + /* Set alarm_poll_interval_ms = 0 to disable. */ + struct delayed_work alarm_poll_work; + u32 alarm_poll_interval_ms; + +#ifdef CONFIG_DEBUG_FS + /* the only debugfs file that can re-arm the poll worker */ + struct dentry *dbg_poll; + struct mpq8646_dbg_reg_ctx *dbg_reg_ctx; +#endif +}; + +static inline struct mpq8646_priv *mpq8646_priv_from_client(struct i2c_client *client) +{ + const struct pmbus_driver_info *info = pmbus_get_driver_info(client); + + return container_of(info, struct mpq8646_priv, info); +} + +/* + * VID-mode m/b/R coefficients, same values as the mpq8785 driver for + * the MPS VID encoding. Per the PMBus Direct formula used by + * pmbus_core, X = (Y * 10^-R - b) / m, so m=64 / b=0 / R=1 yields + * 1.5625 mV per LSB. + */ +#define MPQ8646_VID_M 64 +#define MPQ8646_VID_B 0 +#define MPQ8646_VID_R 1 + +static int mpq8646_identify(struct i2c_client *client, + struct pmbus_driver_info *info) +{ + int vout_mode; + + vout_mode = pmbus_read_byte_data(client, 0, PMBUS_VOUT_MODE); + if (vout_mode < 0) + return vout_mode; + + switch (vout_mode & PB_VOUT_MODE_MODE_MASK) { + case PB_VOUT_MODE_LINEAR: + info->format[PSC_VOLTAGE_OUT] = linear; + break; + case PB_VOUT_MODE_VID: + case PB_VOUT_MODE_DIRECT: + info->format[PSC_VOLTAGE_OUT] = direct; + info->m[PSC_VOLTAGE_OUT] = MPQ8646_VID_M; + info->b[PSC_VOLTAGE_OUT] = MPQ8646_VID_B; + info->R[PSC_VOLTAGE_OUT] = MPQ8646_VID_R; + break; + default: + return -ENODEV; + } + + return 0; +}; + +static int mpq8646_read_byte_data(struct i2c_client *client, int page, int reg) +{ + int ret; + + MPQ8646_DEBUG(client, "read_byte_data page=%d reg=0x%02x\n", page, reg); + + switch (reg) { + case PMBUS_VOUT_MODE: + ret = pmbus_read_byte_data(client, page, reg); + MPQ8646_DEBUG(client, " VOUT_MODE raw=0x%02x ret=%d\n", ret, ret); + if (ret < 0) + return ret; + + if ((ret & PB_VOUT_MODE_MODE_MASK) == PB_VOUT_MODE_VID) + return PB_VOUT_MODE_DIRECT; + + return ret; + case PMBUS_STATUS_BYTE: + case PMBUS_STATUS_CML: + case PMBUS_STATUS_OTHER: + case PMBUS_STATUS_MFR_SPECIFIC: + case PMBUS_STATUS_FAN_12: + case PMBUS_STATUS_FAN_34: + return -ENXIO; + case PMBUS_MFR_LOCATION: + case PMBUS_MFR_DATE: + case PMBUS_MFR_SERIAL: + case PMBUS_IC_DEVICE_ID: + case PMBUS_IC_DEVICE_REV: + MPQ8646_DEBUG(client, " unsupported mfr-info reg 0x%02x -> ENXIO\n", reg); + return -ENXIO; + default: + return -ENODATA; + } +} + +/* + * Reference: ltc2978.c::ltc2978_write_word_data which uses the + * same virtual-register channel for its real chip-side peak reset. + */ +static int mpq8646_write_word_data(struct i2c_client *client, int page, + int reg, u16 word) +{ + struct mpq8646_priv *priv = mpq8646_priv_from_client(client); + int rc; + + switch (reg) { + case PMBUS_VIRT_RESET_VIN_HISTORY: + case PMBUS_VIRT_RESET_VOUT_HISTORY: + case PMBUS_VIRT_RESET_IOUT_HISTORY: + case PMBUS_VIRT_RESET_TEMP_HISTORY: + MPQ8646_DEBUG(client, "reset_history virt reg=0x%04x -> CLEAR_FAULTS\n", + reg); + rc = i2c_smbus_write_byte(priv->client, PMBUS_CLEAR_FAULTS); + if (rc < 0) + MPQ8646_DEBUG(client, " CLEAR_FAULTS rc=%d\n", rc); + return rc < 0 ? rc : 0; + default: + return -ENODATA; /* let pmbus_core do the direct write */ + } +} + +static int mpq8646_read_word_data(struct i2c_client *client, int page, + int phase, int reg) +{ + int rc; + + MPQ8646_DEBUG(client, "read_word_data page=%d phase=%d reg=0x%02x\n", + page, phase, reg); + + switch (reg) { + case PMBUS_READ_VIN: + case PMBUS_READ_VOUT: + case PMBUS_READ_IOUT: + case PMBUS_READ_TEMPERATURE_1: + case PMBUS_STATUS_WORD: + case PMBUS_VOUT_OV_FAULT_LIMIT: + case PMBUS_VOUT_OV_WARN_LIMIT: + case PMBUS_VOUT_UV_WARN_LIMIT: + case PMBUS_VOUT_UV_FAULT_LIMIT: + case PMBUS_IOUT_OC_FAULT_LIMIT: + case PMBUS_IOUT_OC_WARN_LIMIT: + case PMBUS_OT_FAULT_LIMIT: + case PMBUS_OT_WARN_LIMIT: + case PMBUS_VIN_OV_FAULT_LIMIT: + case PMBUS_VIN_OV_WARN_LIMIT: + case PMBUS_VIN_UV_WARN_LIMIT: + case PMBUS_VIN_UV_FAULT_LIMIT: + case PMBUS_MFR_VIN_MAX: + case PMBUS_MFR_VOUT_MAX: + case PMBUS_MFR_IOUT_MAX: + case PMBUS_MFR_MAX_TEMP_1: + break; + case PMBUS_VIRT_RESET_VIN_HISTORY: + case PMBUS_VIRT_RESET_VOUT_HISTORY: + case PMBUS_VIRT_RESET_IOUT_HISTORY: + case PMBUS_VIRT_RESET_TEMP_HISTORY: + return 0; + default: + return -ENODATA; + } + + rc = i2c_smbus_read_word_data(client, reg); + + MPQ8646_DEBUG(client, " reg=0x%02x rc=%d\n", reg, rc); + return rc; +} + +static struct pmbus_driver_info mpq8646_info = { + .pages = 1, + .format[PSC_VOLTAGE_IN] = direct, + .format[PSC_CURRENT_OUT] = direct, + .format[PSC_TEMPERATURE] = direct, + .m[PSC_VOLTAGE_IN] = 4, + .b[PSC_VOLTAGE_IN] = 0, + .R[PSC_VOLTAGE_IN] = 1, + .m[PSC_CURRENT_OUT] = 16, + .b[PSC_CURRENT_OUT] = 0, + .R[PSC_CURRENT_OUT] = 0, + .m[PSC_TEMPERATURE] = 1, + .b[PSC_TEMPERATURE] = 0, + .R[PSC_TEMPERATURE] = 0, + .func[0] = PMBUS_HAVE_VIN | PMBUS_HAVE_VOUT | + PMBUS_HAVE_IOUT | PMBUS_HAVE_TEMP | + PMBUS_HAVE_STATUS_INPUT | PMBUS_HAVE_STATUS_VOUT | + PMBUS_HAVE_STATUS_IOUT | PMBUS_HAVE_STATUS_TEMP, +}; + +#if IS_ENABLED(CONFIG_REGULATOR) +static const struct regulator_desc mpq8646_reg_desc[] = { + PMBUS_REGULATOR("vout", 0), +}; +#endif /* CONFIG_REGULATOR */ + +#if IS_ENABLED(CONFIG_NVMEM) +/* + * Expose using + * /sys/bus/nvmem/devices/<i2c-name>/nvmem + * + * Layout (16 bytes): + * offset 0..1 PROTECTION_LAST (0xFB) word, LE -- NVM + * offset 2..3 MFR_RETRY_TIMES (0xF4) word, LE -- NVM + * offset 4..5 MFR_CONFIG_ID (0xC0) word, LE -- NVM + * offset 6..7 MFR_VBOOT_CFG (0xFC) word, LE -- NVM + * offset 8 MFR_SILICON_REV (0xC3) byte -- NVM + * offset 9..15 reserved (zero-fill, leaves room for additions) + */ +#define MPQ8646_NVMEM_SIZE 16 + +struct mpq8646_nvmem_entry { + unsigned int off; + u8 reg; + bool is_word; +}; + +static const struct mpq8646_nvmem_entry mpq8646_nvmem_map[] = { + { 0, MPS_PROTECTION_LAST, true }, + { 2, MPS_MFR_RETRY_TIMES, true }, + { 4, MPS_MFR_CONFIG_ID, true }, + { 6, MPS_MFR_VBOOT_CFG, true }, + { 8, MPS_MFR_SILICON_REV, false }, +}; + +static int mpq8646_nvmem_read(void *data, unsigned int offset, void *val, + size_t bytes) +{ + struct mpq8646_priv *priv = data; + u8 *out = val; + size_t i; + + if (offset >= MPQ8646_NVMEM_SIZE) + return -EINVAL; + if (offset + bytes > MPQ8646_NVMEM_SIZE) + bytes = MPQ8646_NVMEM_SIZE - offset; + + memset(out, 0, bytes); + + guard(mutex)(&priv->mps_lock); + for (i = 0; i < ARRAY_SIZE(mpq8646_nvmem_map); i++) { + const struct mpq8646_nvmem_entry *e = &mpq8646_nvmem_map[i]; + unsigned int e_start = e->off; + unsigned int e_end = e_start + (e->is_word ? 2 : 1); + u8 raw[2]; + int rc; + unsigned int j; + + if (e_end <= offset || e_start >= offset + bytes) + continue; /* outside requested slice */ + + if (e->is_word) + rc = i2c_smbus_read_word_data(priv->client, e->reg); + else + rc = i2c_smbus_read_byte_data(priv->client, e->reg); + if (rc < 0) + continue; /* leave the zero-fill in place */ + + raw[0] = rc & 0xff; + raw[1] = (rc >> 8) & 0xff; + + for (j = 0; j < e_end - e_start; j++) { + unsigned int abs = e_start + j; + + if (abs >= offset && abs < offset + bytes) + out[abs - offset] = raw[j]; + } + } + return 0; +} +#endif /* CONFIG_NVMEM */ + +static const struct i2c_device_id mpq8646_id[] = { + { .name = "mpq8646" }, + { }, +}; +MODULE_DEVICE_TABLE(i2c, mpq8646_id); + +static const struct of_device_id __maybe_unused mpq8646_of_match[] = { + { .compatible = "mps,mpq8646" }, + {} +}; +MODULE_DEVICE_TABLE(of, mpq8646_of_match); + +static struct pmbus_platform_data mpq8646_no_pec_pdata = { + .flags = PMBUS_NO_CAPABILITY, +}; + +#ifdef CONFIG_DEBUG_FS +/* + * Read-only decode cases in the client's pmbus debugfs directory: + * the MPS-specific STATUS_WORD and PROTECTION_LAST bit decode plus the + * identity/timing registers. + */ + +struct mpq_status_bit { + u16 mask; + const char *name; +}; + +static const struct mpq_status_bit mpq8646_status_word_bits[] = { + { PB_STATUS_VOUT, "VOUT" }, + { PB_STATUS_IOUT_POUT, "IOUT_POUT" }, + { PB_STATUS_INPUT, "INPUT" }, + { PB_STATUS_WORD_MFR, "NVM_SUMMARY" }, + { PB_STATUS_POWER_GOOD_N, "POWER_GOOD#" }, + { PB_STATUS_FANS, "FANS" }, + { PB_STATUS_OTHER, "OTHER" }, + { PB_STATUS_UNKNOWN, "WATCH_DOG" }, + { PB_STATUS_BUSY, "BUSY" }, + { PB_STATUS_OFF, "OFF" }, + { PB_STATUS_VOUT_OV, "VOUT_OV_FAULT" }, + { PB_STATUS_IOUT_OC, "IOUT_OC_FAULT" }, + { PB_STATUS_VIN_UV, "VIN_UV_FAULT" }, + { PB_STATUS_TEMPERATURE, "TEMP" }, + { PB_STATUS_CML, "CML" }, + { PB_STATUS_NONE_ABOVE, "DRMOS_FAULT" }, + { /* sentinel */ } +}; + +/* PROTECTION_LAST (0xFB) bit names, it survives chip POR */ +static const struct mpq_status_bit mpq8646_protection_last_bits[] = { + { BIT(15), "INIT_FAULT" }, + { BIT(14), "NVM_CRC_ERROR" }, + { BIT(13), "NVM_FAULT" }, + { BIT(12), "OC_PHASE_FAULT" }, + { BIT(11), "OTP_SELF_FAULT" }, + { BIT(9), "SWITCH_PRD_FAULT" }, + { BIT(8), "VIN_OV_FAULT" }, + { BIT(7), "VOUT_OV_FAULT" }, + { BIT(6), "VOUT_UV_FAULT" }, + { BIT(5), "OC_TOT_FAULT" }, + { BIT(4), "VIN_UVLO_FAULT" }, + { BIT(3), "DRMOS_OTP" }, + { /* sentinel */ } +}; + +static void mpq8646_print_bits(struct seq_file *s, u16 v, + const struct mpq_status_bit *tab) +{ + const struct mpq_status_bit *t; + bool first = true; + + seq_printf(s, "0x%04x", v); + if (!v) { + seq_puts(s, " [clean]\n"); + return; + } + seq_puts(s, " ["); + for (t = tab; t->mask; t++) { + if (v & t->mask) { + if (!first) + seq_putc(s, ' '); + seq_puts(s, t->name); + first = false; + } + } + seq_puts(s, "]\n"); +} + +static int mpq8646_dbg_status_decoded_show(struct seq_file *s, void *unused) +{ + struct mpq8646_priv *priv = s->private; + int rc; + + scoped_guard(pmbus_lock, priv->client) + rc = i2c_smbus_read_word_data(priv->client, PMBUS_STATUS_WORD); + if (rc < 0) { + seq_printf(s, "ERROR: STATUS_WORD read failed (%d)\n", rc); + return 0; + } + seq_puts(s, "STATUS_WORD: "); + mpq8646_print_bits(s, (u16)rc, mpq8646_status_word_bits); + seq_puts(s, "(MPS extensions: bit12=NVM_SUMMARY, bit8=WATCH_DOG, bit0=DRMOS_FAULT)\n"); + return 0; +} +DEFINE_SHOW_ATTRIBUTE(mpq8646_dbg_status_decoded); + +static int mpq8646_dbg_protection_last_show(struct seq_file *s, void *unused) +{ + struct mpq8646_priv *priv = s->private; + int rc; + + guard(pmbus_lock)(priv->client); + scoped_guard(mutex, &priv->mps_lock) + rc = i2c_smbus_read_word_data(priv->client, MPS_PROTECTION_LAST); + + if (rc < 0) { + seq_printf(s, "ERROR: PROTECTION_LAST read failed (%d)\n", rc); + return 0; + } + seq_puts(s, "PROTECTION_LAST: "); + mpq8646_print_bits(s, (u16)rc, mpq8646_protection_last_bits); + seq_puts(s, "(NVM-backed, survives chip POR)\n"); + return 0; +} +DEFINE_SHOW_ATTRIBUTE(mpq8646_dbg_protection_last); + +struct mpq8646_dbg_reg { + u8 reg; + bool is_word; + const char *name; +}; + +static const struct mpq8646_dbg_reg mpq8646_dbg_regs[] = { + /* MPS vendor extensions (read-only identity / observability) */ + { MPS_MFR_CONFIG_ID, true, "mfr_config_id" }, + { MPS_MFR_CONFIG_CODE_REV, true, "mfr_config_code_rev" }, + { MPS_MFR_SILICON_REV, false, "mfr_silicon_rev" }, + { MPS_MFR_RETRY_TIMES, true, "mfr_retry_times" }, + { MPS_MFR_VBOOT_CFG, true, "mfr_vboot_cfg" }, + /* PMBus 1.3 standard timing / UVLO (read-only introspection) */ + { PMBUS_VIN_ON, true, "vin_on" }, + { PMBUS_VIN_OFF, true, "vin_off" }, + { PMBUS_TON_DELAY, true, "ton_delay" }, + { PMBUS_TON_RISE, true, "ton_rise" }, + { PMBUS_TOFF_DELAY, true, "toff_delay" }, + { PMBUS_TOFF_FALL, true, "toff_fall" }, +}; + +struct mpq8646_dbg_reg_ctx { + struct mpq8646_priv *priv; + const struct mpq8646_dbg_reg *desc; +}; + +static int mpq8646_dbg_reg_show(struct seq_file *s, void *unused) +{ + struct mpq8646_dbg_reg_ctx *ctx = s->private; + int rc; + + guard(pmbus_lock)(ctx->priv->client); + if (ctx->desc->is_word) + rc = i2c_smbus_read_word_data(ctx->priv->client, + ctx->desc->reg); + else + rc = i2c_smbus_read_byte_data(ctx->priv->client, + ctx->desc->reg); + + if (rc < 0) { + seq_printf(s, "ERROR: reg 0x%02x (%s) read failed (%d)\n", + ctx->desc->reg, ctx->desc->name, rc); + return 0; + } + seq_printf(s, "0x%0*x\n", ctx->desc->is_word ? 4 : 2, rc); + return 0; +} +DEFINE_SHOW_ATTRIBUTE(mpq8646_dbg_reg); + +static int mpq8646_dbg_poll_interval_get(void *data, u64 *val) +{ + struct mpq8646_priv *priv = data; + + *val = priv->alarm_poll_interval_ms; + return 0; +} + +static int mpq8646_dbg_poll_interval_set(void *data, u64 val) +{ + struct mpq8646_priv *priv = data; + bool was_off = !priv->alarm_poll_interval_ms; + + priv->alarm_poll_interval_ms = (u32)val; + + if (val && was_off && !priv->client->irq) + schedule_delayed_work(&priv->alarm_poll_work, + msecs_to_jiffies((u32)val)); + return 0; +} +DEFINE_DEBUGFS_ATTRIBUTE(mpq8646_dbg_poll_interval_fops, + mpq8646_dbg_poll_interval_get, + mpq8646_dbg_poll_interval_set, "%llu\n"); + +static void mpq8646_debugfs_register(struct mpq8646_priv *priv) +{ + struct dentry *root; + size_t i; + + root = pmbus_get_debugfs_dir(priv->client); + if (!root) + return; + + /* MPS extensions: status decode + NVM-backed PROTECTION_LAST */ + debugfs_create_file("status_decoded", 0400, root, priv, + &mpq8646_dbg_status_decoded_fops); + debugfs_create_file("protection_last", 0400, root, priv, + &mpq8646_dbg_protection_last_fops); + priv->dbg_poll = + debugfs_create_file_unsafe("alarm_poll_interval_ms", 0600, + root, priv, + &mpq8646_dbg_poll_interval_fops); + + priv->dbg_reg_ctx = devm_kcalloc(&priv->client->dev, + ARRAY_SIZE(mpq8646_dbg_regs), + sizeof(*priv->dbg_reg_ctx), + GFP_KERNEL); + if (!priv->dbg_reg_ctx) + return; + for (i = 0; i < ARRAY_SIZE(mpq8646_dbg_regs); i++) { + priv->dbg_reg_ctx[i].priv = priv; + priv->dbg_reg_ctx[i].desc = &mpq8646_dbg_regs[i]; + debugfs_create_file(mpq8646_dbg_regs[i].name, 0400, + root, &priv->dbg_reg_ctx[i], + &mpq8646_dbg_reg_fops); + } +} + +static void mpq8646_debugfs_unregister(struct mpq8646_priv *priv) +{ + debugfs_remove(priv->dbg_poll); +} +#else +static inline void mpq8646_debugfs_register(struct mpq8646_priv *priv) {} +static inline void mpq8646_debugfs_unregister(struct mpq8646_priv *priv) {} +#endif /* CONFIG_DEBUG_FS */ + +static void mpq8646_alarm_poll_work(struct work_struct *work) +{ + struct mpq8646_priv *priv = container_of(to_delayed_work(work), + struct mpq8646_priv, + alarm_poll_work); + + if (priv->client->irq) + return; /* SMBALERT# wired; polling not needed */ + + if (!priv->alarm_poll_interval_ms) + return; /* polling disabled; don't re-arm */ + + pmbus_check_and_notify_faults(priv->client); + + schedule_delayed_work(&priv->alarm_poll_work, + msecs_to_jiffies(priv->alarm_poll_interval_ms)); +} + +static int mpq8646_probe(struct i2c_client *client) +{ + struct device *dev = &client->dev; + struct pmbus_driver_info *info; + struct mpq8646_priv *priv; + u32 voltage_scale; + int ret; + + priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + priv->client = client; + mutex_init(&priv->mps_lock); + memcpy(&priv->info, &mpq8646_info, sizeof(priv->info)); + info = &priv->info; + + info->identify = mpq8646_identify; + info->read_byte_data = mpq8646_read_byte_data; + info->read_word_data = mpq8646_read_word_data; + info->write_word_data = mpq8646_write_word_data; + dev->platform_data = &mpq8646_no_pec_pdata; + +#if IS_ENABLED(CONFIG_REGULATOR) + info->reg_desc = mpq8646_reg_desc; + info->num_regulators = ARRAY_SIZE(mpq8646_reg_desc); +#endif + + INIT_DELAYED_WORK(&priv->alarm_poll_work, mpq8646_alarm_poll_work); + priv->alarm_poll_interval_ms = MPQ8646_ALARM_POLL_MS_DEFAULT; + + if (!device_property_read_u32(dev, "mps,vout-fb-divider-ratio-permille", + &voltage_scale)) { + if (voltage_scale > MPQ8646_VOUT_SCALE_LOOP_MAX) + return -EINVAL; + + ret = i2c_smbus_write_word_data(client, PMBUS_VOUT_SCALE_LOOP, + voltage_scale); + if (ret) + return ret; + } + + ret = pmbus_do_probe(client, info); + if (ret) + return ret; + + mpq8646_debugfs_register(priv); + + if (!client->irq) + schedule_delayed_work(&priv->alarm_poll_work, + msecs_to_jiffies(priv->alarm_poll_interval_ms)); + +#if IS_ENABLED(CONFIG_NVMEM) + { + struct nvmem_config cfg = { + .dev = &client->dev, + .name = dev_name(&client->dev), + .owner = THIS_MODULE, + .read_only = true, + .root_only = true, + .word_size = 1, + .stride = 1, + .size = MPQ8646_NVMEM_SIZE, + .reg_read = mpq8646_nvmem_read, + .priv = priv, + }; + struct nvmem_device *nv = devm_nvmem_register(&client->dev, &cfg); + + if (IS_ERR(nv)) + dev_warn(&client->dev, + "nvmem snapshot register failed (%pe)\n", + nv); + } +#endif + return 0; +}; + +static void mpq8646_remove(struct i2c_client *client) +{ + struct mpq8646_priv *priv = mpq8646_priv_from_client(client); + + mpq8646_debugfs_unregister(priv); + cancel_delayed_work_sync(&priv->alarm_poll_work); +} + +static struct i2c_driver mpq8646_driver = { + .driver = { + .name = "mpq8646", + .of_match_table = of_match_ptr(mpq8646_of_match), + }, + .probe = mpq8646_probe, + .remove = mpq8646_remove, + .id_table = mpq8646_id, +}; + +module_i2c_driver(mpq8646_driver); + +MODULE_AUTHOR("Vincent Jardin <[email protected]>"); +MODULE_DESCRIPTION("PMBus driver for MPS MPQ8646 (extended observability)"); +MODULE_LICENSE("GPL"); +MODULE_IMPORT_NS("PMBUS"); -- 2.43.0