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[73.252.146.110]) by smtp.gmail.com with ESMTPSA id 12sm13176340pjn.19.2020.11.22.23.45.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 22 Nov 2020 23:45:42 -0800 (PST) From: rentao.bupt@gmail.com To: Jean Delvare , Guenter Roeck , Jonathan Corbet , linux-hwmon@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, openbmc@lists.ozlabs.org, taoren@fb.com, mikechoi@fb.com Subject: [PATCH v4 1/2] hwmon: (max127) Add Maxim MAX127 hardware monitoring driver Date: Sun, 22 Nov 2020 23:45:31 -0800 Message-Id: <20201123074532.3730-2-rentao.bupt@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201123074532.3730-1-rentao.bupt@gmail.com> References: <20201123074532.3730-1-rentao.bupt@gmail.com> MIME-Version: 1.0 X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tao Ren Errors-To: openbmc-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "openbmc" From: Tao Ren Add hardware monitoring driver for the Maxim MAX127 chip. MAX127 min/max range handling code is inspired by the max197 driver. Signed-off-by: Tao Ren --- Changes in v4: - delete unnecessary "#include" lines. - simplify i2c_transfer() error handling. - add mutex to protect ctrl_byte in write_min|max() functions. Changes in v3: - no code change. xdp maintainers were removed from to/cc list. Changes in v2: - replace devm_hwmon_device_register_with_groups() with devm_hwmon_device_register_with_info() API. - divide min/max read and write methods to separate functions. - fix raw-to-vin conversion logic. - refine ctrl_byte handling so mutex is not needed to protect the byte. - improve i2c_transfer() error handling. - a few other improvements (comments, variable naming, and etc.). drivers/hwmon/Kconfig | 9 ++ drivers/hwmon/Makefile | 1 + drivers/hwmon/max127.c | 346 +++++++++++++++++++++++++++++++++++++++++ 3 files changed, 356 insertions(+) create mode 100644 drivers/hwmon/max127.c diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig index 9d600e0c5584..716df51edc87 100644 --- a/drivers/hwmon/Kconfig +++ b/drivers/hwmon/Kconfig @@ -950,6 +950,15 @@ config SENSORS_MAX1111 This driver can also be built as a module. If so, the module will be called max1111. +config SENSORS_MAX127 + tristate "Maxim MAX127 12-bit 8-channel Data Acquisition System" + depends on I2C + help + Say y here to support Maxim's MAX127 DAS chips. + + This driver can also be built as a module. If so, the module + will be called max127. + config SENSORS_MAX16065 tristate "Maxim MAX16065 System Manager and compatibles" depends on I2C diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile index 1083bbfac779..01ca5d3fbad4 100644 --- a/drivers/hwmon/Makefile +++ b/drivers/hwmon/Makefile @@ -127,6 +127,7 @@ obj-$(CONFIG_SENSORS_LTC4260) += ltc4260.o obj-$(CONFIG_SENSORS_LTC4261) += ltc4261.o obj-$(CONFIG_SENSORS_LTQ_CPUTEMP) += ltq-cputemp.o obj-$(CONFIG_SENSORS_MAX1111) += max1111.o +obj-$(CONFIG_SENSORS_MAX127) += max127.o obj-$(CONFIG_SENSORS_MAX16065) += max16065.o obj-$(CONFIG_SENSORS_MAX1619) += max1619.o obj-$(CONFIG_SENSORS_MAX1668) += max1668.o diff --git a/drivers/hwmon/max127.c b/drivers/hwmon/max127.c new file mode 100644 index 000000000000..1c54146b6086 --- /dev/null +++ b/drivers/hwmon/max127.c @@ -0,0 +1,346 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Hardware monitoring driver for MAX127. + * + * Copyright (c) 2020 Facebook Inc. + */ + +#include +#include +#include +#include +#include + +/* + * MAX127 Control Byte. Refer to MAX127 datasheet, Table 1 "Control-Byte + * Format" for details. + */ +#define MAX127_CTRL_START BIT(7) +#define MAX127_CTRL_SEL_SHIFT 4 +#define MAX127_CTRL_RNG BIT(3) +#define MAX127_CTRL_BIP BIT(2) +#define MAX127_CTRL_PD1 BIT(1) +#define MAX127_CTRL_PD0 BIT(0) + +#define MAX127_NUM_CHANNELS 8 +#define MAX127_SET_CHANNEL(ch) (((ch) & 7) << MAX127_CTRL_SEL_SHIFT) + +/* + * MAX127 channel input ranges. Refer to MAX127 datasheet, Table 3 "Range + * and Polarity Selection" for details. + */ +#define MAX127_FULL_RANGE 10000 /* 10V */ +#define MAX127_HALF_RANGE 5000 /* 5V */ + +/* + * MAX127 returns 2 bytes at read: + * - the first byte contains data[11:4]. + * - the second byte contains data[3:0] (MSB) and 4 dummy 0s (LSB). + * Refer to MAX127 datasheet, "Read a Conversion (Read Cycle)" section + * for details. + */ +#define MAX127_DATA_LEN 2 +#define MAX127_DATA_SHIFT 4 + +#define MAX127_SIGN_BIT BIT(11) + +struct max127_data { + struct mutex lock; + struct i2c_client *client; + u8 ctrl_byte[MAX127_NUM_CHANNELS]; +}; + +static int max127_select_channel(struct i2c_client *client, u8 ctrl_byte) +{ + int status; + struct i2c_msg msg = { + .addr = client->addr, + .flags = 0, + .len = sizeof(ctrl_byte), + .buf = &ctrl_byte, + }; + + status = i2c_transfer(client->adapter, &msg, 1); + + return (status == 1) ? 0 : -EIO; +} + +static int max127_read_channel(struct i2c_client *client, long *val) +{ + int status; + u8 i2c_data[MAX127_DATA_LEN]; + struct i2c_msg msg = { + .addr = client->addr, + .flags = I2C_M_RD, + .len = sizeof(i2c_data), + .buf = i2c_data, + }; + + status = i2c_transfer(client->adapter, &msg, 1); + if (status != 1) + return -EIO; + + *val = (i2c_data[1] >> MAX127_DATA_SHIFT) | + ((u16)i2c_data[0] << MAX127_DATA_SHIFT); + return 0; +} + +static long max127_process_raw(u8 ctrl_byte, long raw) +{ + long scale, weight; + + /* + * MAX127's data coding is binary in unipolar mode with 1 LSB = + * (Full-Scale/4096) and two’s complement binary in bipolar mode + * with 1 LSB = [(2 x |FS|)/4096]. + * Refer to MAX127 datasheet, "Transfer Function" section for + * details. + */ + scale = (ctrl_byte & MAX127_CTRL_RNG) ? MAX127_FULL_RANGE : + MAX127_HALF_RANGE; + if (ctrl_byte & MAX127_CTRL_BIP) { + weight = (raw & MAX127_SIGN_BIT); + raw &= ~MAX127_SIGN_BIT; + raw -= weight; + raw *= 2; + } + + return raw * scale / 4096; +} + +static int max127_read_input(struct max127_data *data, int channel, long *val) +{ + long raw; + int status; + struct i2c_client *client = data->client; + u8 ctrl_byte = data->ctrl_byte[channel]; + + mutex_lock(&data->lock); + + status = max127_select_channel(client, ctrl_byte); + if (status) + goto exit; + + status = max127_read_channel(client, &raw); + if (status) + goto exit; + + *val = max127_process_raw(ctrl_byte, raw); + +exit: + mutex_unlock(&data->lock); + return status; +} + +static int max127_read_min(struct max127_data *data, int channel, long *val) +{ + u8 rng_bip = (data->ctrl_byte[channel] >> 2) & 3; + static const int min_input_map[4] = { + 0, /* RNG=0, BIP=0 */ + -MAX127_HALF_RANGE, /* RNG=0, BIP=1 */ + 0, /* RNG=1, BIP=0 */ + -MAX127_FULL_RANGE, /* RNG=1, BIP=1 */ + }; + + *val = min_input_map[rng_bip]; + return 0; +} + +static int max127_read_max(struct max127_data *data, int channel, long *val) +{ + u8 rng_bip = (data->ctrl_byte[channel] >> 2) & 3; + static const int max_input_map[4] = { + MAX127_HALF_RANGE, /* RNG=0, BIP=0 */ + MAX127_HALF_RANGE, /* RNG=0, BIP=1 */ + MAX127_FULL_RANGE, /* RNG=1, BIP=0 */ + MAX127_FULL_RANGE, /* RNG=1, BIP=1 */ + }; + + *val = max_input_map[rng_bip]; + return 0; +} + +static int max127_write_min(struct max127_data *data, int channel, long val) +{ + u8 ctrl; + + mutex_lock(&data->lock); + + ctrl = data->ctrl_byte[channel]; + if (val <= -MAX127_FULL_RANGE) { + ctrl |= (MAX127_CTRL_RNG | MAX127_CTRL_BIP); + } else if (val < 0) { + ctrl |= MAX127_CTRL_BIP; + ctrl &= ~MAX127_CTRL_RNG; + } else { + ctrl &= ~MAX127_CTRL_BIP; + } + data->ctrl_byte[channel] = ctrl; + + mutex_unlock(&data->lock); + + return 0; +} + +static int max127_write_max(struct max127_data *data, int channel, long val) +{ + mutex_lock(&data->lock); + + if (val >= MAX127_FULL_RANGE) + data->ctrl_byte[channel] |= MAX127_CTRL_RNG; + else + data->ctrl_byte[channel] &= ~MAX127_CTRL_RNG; + + mutex_unlock(&data->lock); + + return 0; +} + +static umode_t max127_is_visible(const void *_data, + enum hwmon_sensor_types type, + u32 attr, int channel) +{ + if (type == hwmon_in) { + switch (attr) { + case hwmon_in_input: + return 0444; + + case hwmon_in_min: + case hwmon_in_max: + return 0644; + + default: + break; + } + } + + return 0; +} + +static int max127_read(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long *val) +{ + int status; + struct max127_data *data = dev_get_drvdata(dev); + + if (type != hwmon_in) + return -EOPNOTSUPP; + + switch (attr) { + case hwmon_in_input: + status = max127_read_input(data, channel, val); + break; + + case hwmon_in_min: + status = max127_read_min(data, channel, val); + break; + + case hwmon_in_max: + status = max127_read_max(data, channel, val); + break; + + default: + status = -EOPNOTSUPP; + break; + } + + return status; +} + +static int max127_write(struct device *dev, enum hwmon_sensor_types type, + u32 attr, int channel, long val) +{ + int status; + struct max127_data *data = dev_get_drvdata(dev); + + if (type != hwmon_in) + return -EOPNOTSUPP; + + switch (attr) { + case hwmon_in_min: + status = max127_write_min(data, channel, val); + break; + + case hwmon_in_max: + status = max127_write_max(data, channel, val); + break; + + default: + status = -EOPNOTSUPP; + break; + } + + return status; +} + +static const struct hwmon_ops max127_hwmon_ops = { + .is_visible = max127_is_visible, + .read = max127_read, + .write = max127_write, +}; + +static const struct hwmon_channel_info *max127_info[] = { + HWMON_CHANNEL_INFO(in, + HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX, + HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX, + HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX, + HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX, + HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX, + HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX, + HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX, + HWMON_I_INPUT | HWMON_I_MIN | HWMON_I_MAX), + NULL, +}; + +static const struct hwmon_chip_info max127_chip_info = { + .ops = &max127_hwmon_ops, + .info = max127_info, +}; + +static int max127_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + int i; + struct device *hwmon_dev; + struct max127_data *data; + struct device *dev = &client->dev; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->client = client; + mutex_init(&data->lock); + for (i = 0; i < ARRAY_SIZE(data->ctrl_byte); i++) + data->ctrl_byte[i] = (MAX127_CTRL_START | + MAX127_SET_CHANNEL(i)); + + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, + data, + &max127_chip_info, + NULL); + + return PTR_ERR_OR_ZERO(hwmon_dev); +} + +static const struct i2c_device_id max127_id[] = { + { "max127", 0 }, + { } +}; +MODULE_DEVICE_TABLE(i2c, max127_id); + +static struct i2c_driver max127_driver = { + .class = I2C_CLASS_HWMON, + .driver = { + .name = "max127", + }, + .probe = max127_probe, + .id_table = max127_id, +}; + +module_i2c_driver(max127_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Mike Choi "); +MODULE_AUTHOR("Tao Ren "); +MODULE_DESCRIPTION("MAX127 Hardware Monitoring driver"); From patchwork Mon Nov 23 07:45:32 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tao Ren X-Patchwork-Id: 1404665 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4CffSG3KsDz9sRR for ; Mon, 23 Nov 2020 18:49:34 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20161025 header.b=Kr0nPw4b; dkim-atps=neutral Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 4CffSG2y3yzDqJt for ; 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[73.252.146.110]) by smtp.gmail.com with ESMTPSA id 12sm13176340pjn.19.2020.11.22.23.45.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 22 Nov 2020 23:45:43 -0800 (PST) From: rentao.bupt@gmail.com To: Jean Delvare , Guenter Roeck , Jonathan Corbet , linux-hwmon@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, openbmc@lists.ozlabs.org, taoren@fb.com, mikechoi@fb.com Subject: [PATCH v4 2/2] docs: hwmon: Document max127 driver Date: Sun, 22 Nov 2020 23:45:32 -0800 Message-Id: <20201123074532.3730-3-rentao.bupt@gmail.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20201123074532.3730-1-rentao.bupt@gmail.com> References: <20201123074532.3730-1-rentao.bupt@gmail.com> X-BeenThere: openbmc@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development list for OpenBMC List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Tao Ren Errors-To: openbmc-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "openbmc" From: Tao Ren Add documentation for the max127 hardware monitoring driver. Signed-off-by: Tao Ren Reviewed-by: Guenter Roeck --- Changes in v4: - None. Changes in v3: - no code change. xdp maintainers were removed from to/cc list. Changes in v2: - add more description for min/max sysfs nodes. - convert values from volt to millivolt in the document. Documentation/hwmon/index.rst | 1 + Documentation/hwmon/max127.rst | 45 ++++++++++++++++++++++++++++++++++ 2 files changed, 46 insertions(+) create mode 100644 Documentation/hwmon/max127.rst diff --git a/Documentation/hwmon/index.rst b/Documentation/hwmon/index.rst index 408760d13813..0a07b6000c20 100644 --- a/Documentation/hwmon/index.rst +++ b/Documentation/hwmon/index.rst @@ -111,6 +111,7 @@ Hardware Monitoring Kernel Drivers ltc4245 ltc4260 ltc4261 + max127 max16064 max16065 max1619 diff --git a/Documentation/hwmon/max127.rst b/Documentation/hwmon/max127.rst new file mode 100644 index 000000000000..dc192dd9c37c --- /dev/null +++ b/Documentation/hwmon/max127.rst @@ -0,0 +1,45 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later + +Kernel driver max127 +==================== + +Author: + + * Tao Ren + +Supported chips: + + * Maxim MAX127 + + Prefix: 'max127' + + Datasheet: https://datasheets.maximintegrated.com/en/ds/MAX127-MAX128.pdf + +Description +----------- + +The MAX127 is a multirange, 12-bit data acquisition system (DAS) providing +8 analog input channels that are independently software programmable for +a variety of ranges. The available ranges are {0,5V}, {0,10V}, {-5,5V} +and {-10,10V}. + +The MAX127 features a 2-wire, I2C-compatible serial interface that allows +communication among multiple devices using SDA and SCL lines. + +Sysfs interface +--------------- + + ============== ============================================================== + in[0-7]_input The input voltage (in mV) of the corresponding channel. + RO + + in[0-7]_min The lower input limit (in mV) for the corresponding channel. + ADC range and LSB will be updated when the limit is changed. + For the MAX127, it will be adjusted to -10000, -5000, or 0. + RW + + in[0-7]_max The higher input limit (in mV) for the corresponding channel. + ADC range and LSB will be updated when the limit is changed. + For the MAX127, it will be adjusted to 0, 5000, or 10000. + RW + ============== ==============================================================