From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EF50CC2B9F4 for ; Mon, 28 Jun 2021 15:41:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D2B2060233 for ; Mon, 28 Jun 2021 15:41:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235926AbhF1Pnm (ORCPT ); Mon, 28 Jun 2021 11:43:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51718 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232768AbhF1Pnf (ORCPT ); Mon, 28 Jun 2021 11:43:35 -0400 Received: from mail-oi1-x234.google.com (mail-oi1-x234.google.com [IPv6:2607:f8b0:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 00290C051EC5 for ; Mon, 28 Jun 2021 07:58:51 -0700 (PDT) Received: by mail-oi1-x234.google.com with SMTP id h9so22314607oih.4 for ; Mon, 28 Jun 2021 07:58:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:to:cc:references:from:subject:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=isNEzHjDWpNvMixL8Mdi+HfdRXSNy14jjNvs03tt/2k=; b=LpSo5tWQj82JHeeRFgIpX0vpOmZPkVyKggTqFWPMTAcEs0ngwWoiOuR2ANbGuYcy4J ea3Md/PYf1OO/hR6zo/vvL4n2j/5XfSXoSvk6/l0rXc4/0dOS2wE9YD2WXXyM6PPGwmm MQIuAEbyIfRA9TkFB14mbOeOaiRzAbdCoTRrZ/KlsBI7dcYsa6BYweN53tRbdVEoE7wU avyhfzACbqc8u27szqyCezvez6rS25eCFW0jQ9m2BfPz9WwwLATscEdSB5eiRUItJao8 3olMN8xPr+0Jp3yFLDWC6s+wwcGMfXGuYO6XhNrYmv9Dj9dl7NP4Oa0WYHrGlcLpjoae OhyQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:to:cc:references:from:subject:message-id :date:user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=isNEzHjDWpNvMixL8Mdi+HfdRXSNy14jjNvs03tt/2k=; b=tzJbMcwJlPsNFo41Sa6K6lpW03KGO4dglncgBtbLF/1zbpkKLpKAgpBX+iNDnP61N9 kxkzv75skT3OIablRGYsmHm/uGbdYZKWg9BKBOKIJge09g2UV7iZM2vkjYIbU26Ulv5O rtmEzKR92GiOps2rPF9Hhp1sjbwLnCBVV4GiyueqFQBgwkvtiYWdg/yOKY4VlMCUNm/S EOE1XikR+5PWqH1K5wFhXr+u/GKUIkvQsvIuRVa7ROxMLWnxxcG55a7v5U5l0CZ5hJvz pgisyv1D8vFi8bbirav1voNqH7WNQjNbmcUGYRWP/Dj/3SSCal7gy5IbfIhjog5dQ44v Y6Eg== X-Gm-Message-State: AOAM531R4TbNG2/Vb7vyKTmZa1sJJENX57xcAtxbi1v6yY28Tmf5vfIw TYTOL723UL2e5H0GeP1maDE= X-Google-Smtp-Source: ABdhPJyH5XzjsNJC8OBXKGK2BpcdiJFhAmsbY/gqiyOeLlImp8q44Tz/DmYWrE7HAJsWhEveSsd6XQ== X-Received: by 2002:aca:b5d6:: with SMTP id e205mr20621188oif.91.1624892331249; Mon, 28 Jun 2021 07:58:51 -0700 (PDT) Received: from server.roeck-us.net ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id r2sm3466688otd.54.2021.06.28.07.58.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 28 Jun 2021 07:58:50 -0700 (PDT) Sender: Guenter Roeck To: Naveen Krishna Chatradhi , linux-hwmon@vger.kernel.org Cc: Akshay Gupta References: <20210625132544.18094-1-nchatrad@amd.com> From: Guenter Roeck Subject: Re: [PATCH 1/3] hwmon: sbrmi: Add support for sbrmi power module Message-ID: <26e0f4b6-5a5d-bf79-7691-b9e3a8c7ec43@roeck-us.net> Date: Mon, 28 Jun 2021 07:58:49 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.1 MIME-Version: 1.0 In-Reply-To: <20210625132544.18094-1-nchatrad@amd.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org On 6/25/21 6:25 AM, Naveen Krishna Chatradhi wrote: > From: Akshay Gupta > > On AMD platforms the Out-of-band access is provided by Advanced Platform Management This is a bit too long for checkpatch. > Link (APML), APML is a SMBus v2.0 compatible 2-wire processor client interface. > APML is also referred as the sideband interface (SBI). > > APML is used to communicate with the Remote Management Interface > (SB-Remote Management Interface (SB-RMI) which provides Soft Mailbox messages > to report power consumption and power limits of the CPU socket. > > - This module add support to read power consumption, > power limit & max power limit and write power limit. > - To instantiate this driver on an AMD CPU with SB-RMI support, > the i2c bus number would be the bus connected from the board > management controller (BMC) to the CPU. > This is a bit vague. Would this driver be instantiated on the host CPU or on the BMC ? > Signed-off-by: Akshay Gupta > Signed-off-by: Naveen Krishna Chatradhi > --- > drivers/hwmon/Kconfig | 10 ++ > drivers/hwmon/Makefile | 1 + > drivers/hwmon/sbrmi.c | 394 +++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 405 insertions(+) > create mode 100644 drivers/hwmon/sbrmi.c > > diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig > index 87624902ea80..d1813ea8382c 100644 > --- a/drivers/hwmon/Kconfig > +++ b/drivers/hwmon/Kconfig > @@ -1551,6 +1551,16 @@ config SENSORS_SBTSI > This driver can also be built as a module. If so, the module will > be called sbtsi_temp. > > +config SENSORS_SBRMI > + tristate "Emulated SB-RMI sensor" > + depends on I2C > + help > + If you say yes here you get support for emulated RMI > + sensors on AMD SoCs with APML interface connected to a BMC device. > + > + This driver can also be built as a module. If so, the module will > + be called sbrmi. > + > config SENSORS_SHT15 > tristate "Sensiron humidity and temperature sensors. SHT15 and compat." > depends on GPIOLIB || COMPILE_TEST > diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile > index 59e78bc212cf..8031acf58936 100644 > --- a/drivers/hwmon/Makefile > +++ b/drivers/hwmon/Makefile > @@ -164,6 +164,7 @@ obj-$(CONFIG_SENSORS_PWM_FAN) += pwm-fan.o > obj-$(CONFIG_SENSORS_RASPBERRYPI_HWMON) += raspberrypi-hwmon.o > obj-$(CONFIG_SENSORS_S3C) += s3c-hwmon.o > obj-$(CONFIG_SENSORS_SBTSI) += sbtsi_temp.o > +obj-$(CONFIG_SENSORS_SBRMI) += sbrmi.o > obj-$(CONFIG_SENSORS_SCH56XX_COMMON)+= sch56xx-common.o > obj-$(CONFIG_SENSORS_SCH5627) += sch5627.o > obj-$(CONFIG_SENSORS_SCH5636) += sch5636.o > diff --git a/drivers/hwmon/sbrmi.c b/drivers/hwmon/sbrmi.c > new file mode 100644 > index 000000000000..c35829513459 > --- /dev/null > +++ b/drivers/hwmon/sbrmi.c > @@ -0,0 +1,394 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * sbrmi.c - hwmon driver for a SB-RMI mailbox > + * compliant AMD SoC device. > + * > + * Copyright (C) 2020-2021 Advanced Micro Devices, Inc. > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include I don't immediately see why this include is needed. > +#include This looks wrong, and I don't immediately see why it would be needed. > +#include Alphabetic include file order, please. > + > +/* Do not allow setting negative power limit */ > +#define SBRMI_PWR_MIN 0 > +/* Mask for Status Register bit[1] */ > +#define SW_ALERT_MASK 0x2 > + Please always use #defineDEFINITIONvalue ^^^^^ > +/* Software Interrupt for triggering */ > +#define START_CMD 0x80 > +#define TRIGGER_MAILBOX 0x01 > + > +/* > + * SB-RMI supports soft mailbox service request to MP1 (power management > + * firmware) through SBRMI inbound/outbound message registers. > + * SB-RMI message IDs > + */ > +enum sbrmi_msg_id { > + SBRMI_READ_PKG_PWR_CONSUMPTION = 0x1, > + SBRMI_WRITE_PKG_PWR_LIMIT, > + SBRMI_READ_PKG_PWR_LIMIT, > + SBRMI_READ_PKG_MAX_PWR_LIMIT, > +}; > + > +/* SB-RMI registers */ > +enum sbrmi_reg { > + SBRMI_CTRL = 0x01, > + SBRMI_STATUS, > + SBRMI_OUTBNDMSG0 = 0x30, > + SBRMI_OUTBNDMSG1, > + SBRMI_OUTBNDMSG2, > + SBRMI_OUTBNDMSG3, > + SBRMI_OUTBNDMSG4, > + SBRMI_OUTBNDMSG5, > + SBRMI_OUTBNDMSG6, > + SBRMI_OUTBNDMSG7, > + SBRMI_INBNDMSG0, > + SBRMI_INBNDMSG1, > + SBRMI_INBNDMSG2, > + SBRMI_INBNDMSG3, > + SBRMI_INBNDMSG4, > + SBRMI_INBNDMSG5, > + SBRMI_INBNDMSG6, > + SBRMI_INBNDMSG7, > + SBRMI_SW_INTERRUPT, > +}; > + > +/* > + * Each client has this additional data > + */ Please be consistent with comments: This does not really need to be a multi-line comment. While that does not really matter, you use a single-line comment to describe the next structure. Please make it both either single-line or multi-line. > +struct sbrmi_data { > + struct i2c_client *client; > + struct mutex lock; > +}; > + > +/* Mailbox message data format */ > +union mailbox_word { > + u8 bytes[4]; > + u32 value; That strongly suggests that the driver will only work on either little-endian or big-endian systems, depending on the byte order of transfers. Please restrict it accordingly. > +}; > + > +struct sbrmi_mailbox_msg { > + u8 cmd; > + bool read; > + union mailbox_word data_in; > + union mailbox_word data_out; > +}; > + > +static int print_mailbox_error(struct sbrmi_data *data) > +{ Nit> Many functions only use data>client and, in some cases, dereference it several times. It might be easier to just pass 'client'. > + int status; > + > + /* Mailbox error code will be written by Firmware in > + * SBRMI::OutBndMsg_inst7 (SBRMI_x37) > + */ /* * Please use standard multi-line comments. Applies to entire driver. */ > + status = i2c_smbus_read_byte_data(data->client, SBRMI_OUTBNDMSG7); > + if (status < 0) { > + pr_err("SMBUS translation failed\n"); > + return status; > + } > + > + switch (status) { > + case 0x0: /* Success */ > + break; > + case 0x1: > + pr_err("Mailbox message command is aborted\n"); > + break; > + case 0x2: > + pr_err("Unknown mailbox message\n"); > + break; > + case 0x3: > + pr_err("Invalid core is specified in mailbox message parameters\n"); > + break; > + default: > + pr_err("Unknown Error\n"); > + } Is this noise necessary ? I am concerned that, if it occurs, it would be persistent and fill up the kernel log with noise. > + > + return status; Error codes are supposed to be negative and standard Linux error codes. Please convert the above errors to standard Linux error codes. > +} > + > +static int sbrmi_enable_alert(struct sbrmi_data *data) > +{ > + int ctrl; > + > + /* Enable the SB-RMI Software alert status > + * by writing 0 to bit 4 of Control register(0x1) > + */ > + ctrl = i2c_smbus_read_byte_data(data->client, SBRMI_CTRL); > + if (ctrl < 0) > + return ctrl; > + > + if (ctrl & 0x10) { > + ctrl &= ~0x10; > + return i2c_smbus_write_byte_data(data->client, > + SBRMI_CTRL, ctrl); > + } > + > + return 0; > +} > + > +static int rmi_mailbox_xfer(struct sbrmi_data *data, > + struct sbrmi_mailbox_msg *msg) > +{ > + union mailbox_word output, input; > + int i, err = 0, retry = 10; Initializing 'err' is unnecessary. > + int sw_status; > + > + mutex_lock(&data->lock); > + > + err = sbrmi_enable_alert(data); > + if (err < 0) > + goto exit_unlock; > + > + /* Indicate firmware a command is to be serviced */ > + err = i2c_smbus_write_byte_data(data->client, > + SBRMI_INBNDMSG7, START_CMD); > + if (err < 0) > + goto exit_unlock; > + > + /* Write the command to SBRMI::InBndMsg_inst0 */ > + err = i2c_smbus_write_byte_data(data->client, > + SBRMI_INBNDMSG0, msg->cmd); > + if (err < 0) > + goto exit_mod; > + > + /* > + * For both read and write the initiator (BMC) writes > + * Command Data In[31:0] to SBRMI::InBndMsg_inst[4:1] > + * SBRMI_x3C(MSB):SBRMI_x39(LSB) > + */ > + input = msg->data_in; > + for (i = 0; i < 3; i++) { This writes 3 bytes. Is that on purpose ? If so please explain since the above suggests that 4 bytes should be written. > + err = i2c_smbus_write_byte_data(data->client, > + (SBRMI_INBNDMSG1 + i), Unnecessary ( ) > + input.bytes[i]); > + if (err < 0) > + goto exit_mod; > + } > + > + /* > + * Write 0x01 to SBRMI::SoftwareInterrupt to notify firmware to > + * perform the requested read or write command > + */ > + err = i2c_smbus_write_byte_data(data->client, > + SBRMI_SW_INTERRUPT, TRIGGER_MAILBOX); > + if (err < 0) > + goto exit_mod; > + > + /* > + * Firmware will write SBRMI::Status[SwAlertSts]=1 to generate > + * an ALERT (if enabled) to initiator (BMC) to indicate completion > + * of the requested command > + */ > + do { > + sw_status = i2c_smbus_read_byte_data(data->client, > + SBRMI_STATUS); > + if (sw_status < 0) { > + err = sw_status; > + goto exit_mod; > + } > + if (sw_status & SW_ALERT_MASK) > + break; > + usleep_range(50, 100); > + } while (retry--); > + > + if (retry < 0) { > + pr_err("Firmware fail to indicate command colmpletion\n"); completion > + err = -1; > + goto exit_mod; > + } > + > + /* > + * For a read operation, the initiator (BMC) reads the firmware response > + * Command Data Out[31:0] from SBRMI::OutBndMsg_inst[4:1] > + * {SBRMI_x34(MSB):SBRMI_x31(LSB)}. > + */ > + if (msg->read) { > + for (i = 0; i < 4; i++) { > + output.bytes[i] = i2c_smbus_read_byte_data(data->client, > + (SBRMI_OUTBNDMSG1 + i)); Unnecessary (). > + if (output.bytes[i] < 0) { output.bytes is defined as u8. This will not catch errors. > + err = output.bytes[i]; > + goto exit_mod; > + } > + } > + } > + msg->data_out = output; > + > + /* > + * BMC must write 1'b1 to SBRMI::Status[SwAlertSts] to clear the > + * ALERT to initiator > + */ > + err = i2c_smbus_write_byte_data(data->client, SBRMI_STATUS, > + (sw_status | SW_ALERT_MASK)); Unnecessary (). > + > +exit_mod: > + if (err < 0) > + pr_err("SMBUS translation failed\n"); > + else > + err = print_mailbox_error(data); > +exit_unlock: > + mutex_unlock(&data->lock); > + return err; > +} > + > +static int sbrmi_read(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long *val) > +{ > + struct sbrmi_data *data = dev_get_drvdata(dev); > + struct sbrmi_mailbox_msg msg = { 0 }; > + int ret; > + > + if (type != hwmon_power) > + return -EINVAL; > + > + msg.read = true; > + switch (attr) { > + case hwmon_power_input: > + msg.cmd = SBRMI_READ_PKG_PWR_CONSUMPTION; > + ret = rmi_mailbox_xfer(data, &msg); > + break; > + case hwmon_power_cap: > + msg.cmd = SBRMI_READ_PKG_PWR_LIMIT; > + ret = rmi_mailbox_xfer(data, &msg); > + break; > + case hwmon_power_cap_max: > + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; > + ret = rmi_mailbox_xfer(data, &msg); > + break; > + default: > + return -EINVAL; > + } > + /* > + * hwmon power attributes are in microWatt > + */ > + *val = (long)msg.data_out.value * 1000; > + return ret; > +} > + > +static int sbrmi_write(struct device *dev, enum hwmon_sensor_types type, > + u32 attr, int channel, long val) > +{ > + struct sbrmi_data *data = dev_get_drvdata(dev); > + struct sbrmi_mailbox_msg msg = { 0 }; > + > + if (type != hwmon_power && attr != hwmon_power_cap) > + return -EINVAL; > + /* > + * hwmon power attributes are in microWatt > + * mailbox read/write is in mWatt > + */ > + val /= 1000; > + > + msg.cmd = SBRMI_READ_PKG_MAX_PWR_LIMIT; > + msg.data_in.value = 0; > + msg.read = true; > + rmi_mailbox_xfer(data, &msg); > + > + val = clamp_val(val, SBRMI_PWR_MIN, msg.data_out.value); > + > + msg.cmd = SBRMI_WRITE_PKG_PWR_LIMIT; > + msg.data_in.value = val; > + msg.read = false; > + > + return rmi_mailbox_xfer(data, &msg); > +} > + > +static umode_t sbrmi_is_visible(const void *data, > + enum hwmon_sensor_types type, > + u32 attr, int channel) > +{ > + switch (type) { > + case hwmon_power: > + switch (attr) { > + case hwmon_power_input: > + case hwmon_power_cap_max: > + return 0444; > + case hwmon_power_cap: > + return 0644; > + } > + break; > + default: > + break; > + } > + return 0; > +} > + > +static const struct hwmon_channel_info *sbrmi_info[] = { > + HWMON_CHANNEL_INFO(power, > + HWMON_P_INPUT | HWMON_P_CAP | HWMON_P_CAP_MAX), > + NULL > +}; > + > +static const struct hwmon_ops sbrmi_hwmon_ops = { > + .is_visible = sbrmi_is_visible, > + .read = sbrmi_read, > + .write = sbrmi_write, > +}; > + > +static const struct hwmon_chip_info sbrmi_chip_info = { > + .ops = &sbrmi_hwmon_ops, > + .info = sbrmi_info, > +}; > + > +static int sbrmi_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct device *dev = &client->dev; > + struct device *hwmon_dev; > + struct sbrmi_data *data; > + > + if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) { > + dev_err(&client->dev, "adapter does not support true I2C\n"); Why would that matter? It only uses SMBus functions. > + return -ENODEV; > + } > + > + data = devm_kzalloc(dev, sizeof(struct sbrmi_data), GFP_KERNEL); > + if (!data) > + return -ENOMEM; > + > + data->client = client; > + mutex_init(&data->lock); > + > + hwmon_dev = devm_hwmon_device_register_with_info(dev, client->name, data, > + &sbrmi_chip_info, NULL); > + > + return PTR_ERR_OR_ZERO(hwmon_dev); > +} > + > +static const struct i2c_device_id sbrmi_id[] = { > + {"sbrmi", 0}, > + {} > +}; > +MODULE_DEVICE_TABLE(i2c, sbrmi_id); > + > +static const struct of_device_id __maybe_unused sbrmi_of_match[] = { > + { > + .compatible = "amd,sbrmi", > + }, > + { }, > +}; > +MODULE_DEVICE_TABLE(of, sbrmi_of_match); > + > +static struct i2c_driver sbrmi_driver = { > + .class = I2C_CLASS_HWMON, > + .driver = { > + .name = "sbrmi", > + .of_match_table = of_match_ptr(sbrmi_of_match), > + }, > + .probe = sbrmi_probe, > + .id_table = sbrmi_id, > +}; > + > +module_i2c_driver(sbrmi_driver); > + > +MODULE_AUTHOR("Akshay Gupta "); > +MODULE_DESCRIPTION("Hwmon driver for AMD SB-RMI emulated sensor"); > +MODULE_LICENSE("GPL"); >