From patchwork Wed Apr 22 17:27:14 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Grant Peltier X-Patchwork-Id: 11504325 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id AB92281 for ; Wed, 22 Apr 2020 17:27:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D6352082E for ; Wed, 22 Apr 2020 17:27:19 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="irysa7bw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726245AbgDVR1T (ORCPT ); Wed, 22 Apr 2020 13:27:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45230 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726060AbgDVR1S (ORCPT ); Wed, 22 Apr 2020 13:27:18 -0400 Received: from mail-ot1-x344.google.com (mail-ot1-x344.google.com [IPv6:2607:f8b0:4864:20::344]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EDD8EC03C1A9; Wed, 22 Apr 2020 10:27:17 -0700 (PDT) Received: by mail-ot1-x344.google.com with SMTP id g19so2791172otk.5; Wed, 22 Apr 2020 10:27:17 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=lGMuCEUNgUJKvxrdFYy6VL+m3yxy35rC9TO8c7j53gE=; b=irysa7bwPqKGnkrxEwwAVavMbRPWuhNeclCgtgjF0ZIA8Am0ed+Ughro/yxfEa23zx T0baF/abcEO3LEozaHeMLxk+QT3av5dNDbwT9oALeSSjSL3jgcHF4V4Kg32hT80MtGSw cWjlHEuQVuAwY8nYsLD2QLnKlna0mOiJx+VZ5p8JxYhen/5YhJJXx7x9ld9HVId93sSm imF5brBZPgenODGakBBeJH0a9Z0mRPfYFzA4ndrV0s6yfIYj9wjuwT4GbXvtX4amEMOB GN9ZBeM04bbIsegaWOeFwSrIXY3JQPKfaV+nrwHnw9eQznfytZHAvYSxXZoYl469BBuJ u/UA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to:user-agent; bh=lGMuCEUNgUJKvxrdFYy6VL+m3yxy35rC9TO8c7j53gE=; b=BWJx23X0nD2xZT6rQ1mibuw8eAAkwbcAUWoUodKMLbPsNjfDwgD21x9PhjUd8KdU8l PC5i3xMGBNw6QwwPCIBASebkbzUYVVRaXfFljEwZfndivWGPgPLXMy4vXs4a/pquMmSe vE1DeCL0MwpT+jG0CDCV8XtxdTTFgmeXS8vBmD/euYA8dfw3p7TvBfbTPfPLacYBxuzi d54vSWdZczEw9D3jJkgr2wBBTDbnlzybLLblUf69U+WrvreGm59UoD9s2hqSmu4wArC6 aoXADobcvHAQcdoeBE8LPd30bO/c2YHApk3fCJkx6pNeeTd6UfG25tI5v+l/8nrpqawF wcZg== X-Gm-Message-State: AGi0PuYc0zfrL/41iLAweQlGSH6hC69mGgWpuqgw/2jTxaZJFXg++j2I dpkqUQLcsP8U6kl2IcHrc7E= X-Google-Smtp-Source: APiQypKX9OeiSsVuTkjnszduMJdfCrC9GZ7tmpw9rZVZaMfFTeBUU5mvCEJ1dS/umnAtbdlFEo9clg== X-Received: by 2002:a9d:6419:: with SMTP id h25mr78548otl.191.1587576437016; Wed, 22 Apr 2020 10:27:17 -0700 (PDT) Received: from raspberrypi (99-189-78-97.lightspeed.austtx.sbcglobal.net. [99.189.78.97]) by smtp.gmail.com with ESMTPSA id b19sm360466oii.1.2020.04.22.10.27.16 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Apr 2020 10:27:16 -0700 (PDT) Date: Wed, 22 Apr 2020 12:27:14 -0500 From: Grant Peltier To: linux@roeck-us.net, linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org Cc: adam.vaughn.xh@renesas.com, grant.peltier.jg@renesas.com Subject: [PATCH v2 1/2] hwmon: (pmbus/isl68137) add debugfs config and black box endpoints Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org Add debugfs endpoints to support features of 2nd generation Renesas digital multiphase voltage regulators that are not compatible with sysfs. The read_black_box endpoint allows users to read the contents of a RAM segment used to record fault conditions within Gen 2 devices. The write_config endpoint allows users to write configuration hex files to Gen 2 devices which modify how they operate. Signed-off-by: Grant Peltier --- drivers/hwmon/pmbus/isl68137.c | 460 ++++++++++++++++++++++++++++++++- 1 file changed, 457 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/pmbus/isl68137.c b/drivers/hwmon/pmbus/isl68137.c index 0c622711ef7e..455235a7a56b 100644 --- a/drivers/hwmon/pmbus/isl68137.c +++ b/drivers/hwmon/pmbus/isl68137.c @@ -7,10 +7,12 @@ * */ +#include #include #include #include #include +#include #include #include #include @@ -18,8 +20,22 @@ #include "pmbus.h" -#define ISL68137_VOUT_AVS 0x30 -#define RAA_DMPVR2_READ_VMON 0xc8 +#define ISL68137_VOUT_AVS 0x30 +#define RAA_DMPVR2_DMA_FIX 0xc5 +#define RAA_DMPVR2_DMA_SEQ 0xc6 +#define RAA_DMPVR2_DMA_ADDR 0xc7 +#define RAA_DMPVR2_READ_VMON 0xc8 +#define RAA_DMPVR2_BB_BASE_ADDR 0xef80 +#define RAA_DMPVR2_BB_WSIZE 4 +#define RAA_DMPVR2_BB_WCNT 32 +#define RAA_DMPVR2_BB_BUF_SIZE 288 +#define RAA_DMPVR2_NVM_CNT_ADDR 0x00c2 +#define RAA_DMPVR2_PRGM_STATUS_ADDR 0x0707 +#define RAA_DMPVR2_BANK0_STATUS_ADDR 0x0709 +#define RAA_DMPVR2_BANK1_STATUS_ADDR 0x070a +#define RAA_DMPVR2_CFG_MAX_SLOT 16 +#define RAA_DMPVR2_CFG_HEAD_LEN 290 +#define RAA_DMPVR2_CFG_SLOT_LEN 358 enum chips { isl68137, @@ -71,6 +87,21 @@ enum variants { raa_dmpvr2_hv, }; +enum { + RAA_DMPVR2_DEBUGFS_CFG_W = 0, + RAA_DMPVR2_DEBUGFS_BB_R, + RAA_DMPVR2_DEBUGFS_NUM_ENTRIES, +}; + +struct raa_dmpvr2_ctrl { + enum chips part; + struct i2c_client *client; + int debugfs_entries[RAA_DMPVR2_DEBUGFS_NUM_ENTRIES]; +}; + +#define to_ctrl(x, y) container_of((x), struct raa_dmpvr2_ctrl, \ + debugfs_entries[(y)]) + static ssize_t isl68137_avs_enable_show_page(struct i2c_client *client, int page, char *buf) @@ -157,6 +188,395 @@ static const struct attribute_group *isl68137_attribute_groups[] = { NULL, }; +/** + * Helper function required since linux SMBus implementation does not currently + * (v5.6) support the SMBus 3.0 "Read 32" protocol + */ +static s32 raa_dmpvr2_smbus_read32(const struct i2c_client *client, u8 command, + unsigned char *data) +{ + int status; + unsigned char msgbuf[1]; + struct i2c_msg msg[2] = { + { + .addr = client->addr, + .flags = client->flags, + .len = 1, + .buf = msgbuf, + }, + { + .addr = client->addr, + .flags = client->flags | I2C_M_RD, + .len = 4, + .buf = data, + }, + }; + + msgbuf[0] = command; + status = i2c_transfer(client->adapter, msg, 2); + if (status != 2) + return status; + return 0; +} + +/** + * Helper function required since linux SMBus implementation does not currently + * (v5.6) support the SMBus 3.0 "Write 32" protocol + */ +static s32 raa_dmpvr2_smbus_write32(const struct i2c_client *client, + u8 command, u32 value) +{ + int status; + unsigned char msgbuf[5]; + struct i2c_msg msg[1] = { + { + .addr = client->addr, + .flags = client->flags, + .len = 5, + .buf = msgbuf, + }, + }; + msgbuf[0] = command; + msgbuf[1] = value & 0x0FF; + msgbuf[2] = (value >> 8) & 0x0FF; + msgbuf[3] = (value >> 16) & 0x0FF; + msgbuf[4] = (value >> 24) & 0x0FF; + status = i2c_transfer(client->adapter, msg, 1); + if (status != 1) + return status; + return 0; +} + +static ssize_t raa_dmpvr2_read_black_box(struct raa_dmpvr2_ctrl *ctrl, + char __user *buf, size_t len, + loff_t *ppos) +{ + int i, j; + u16 addr = RAA_DMPVR2_BB_BASE_ADDR; + unsigned char data[RAA_DMPVR2_BB_WSIZE] = { 0 }; + char out[RAA_DMPVR2_BB_BUF_SIZE] = { 0 }; + char *optr = out; + + i2c_smbus_write_word_data(ctrl->client, RAA_DMPVR2_DMA_ADDR, addr); + for (i = 0; i < RAA_DMPVR2_BB_WCNT; i++) { + raa_dmpvr2_smbus_read32(ctrl->client, RAA_DMPVR2_DMA_SEQ, + data); + for (j = 0; j < RAA_DMPVR2_BB_WSIZE; j++) + optr += snprintf(optr, sizeof(out), "%02X", data[j]); + *optr = '\n'; + optr++; + } + + return simple_read_from_buffer(buf, len, ppos, &out, sizeof(out)); +} + +struct raa_dmpvr_cfg_cmd { + u8 cmd; + u8 len; + u8 data[4]; +}; + +struct raa_dmpvr2_cfg { + u8 dev_id[4]; + u8 dev_rev[4]; + int slot_cnt; + int cmd_cnt; + struct raa_dmpvr_cfg_cmd *cmds; + u8 crc[4]; +}; + +/** + * Helper function to handle hex string to byte conversions + */ +static int raa_dmpvr2_hextou8(char *buf, u8 *res) +{ + char s[3]; + + s[0] = buf[0]; + s[1] = buf[1]; + s[2] = '\0'; + return kstrtou8(s, 16, res); +} + +static int raa_dmpvr2_parse_cfg(char *buf, struct raa_dmpvr2_cfg *cfg) +{ + const int lsta = 2; + const int csta = 6; + const int dsta = 8; + char *cptr, *line; + int lcnt = 1; + int ccnt = 0; + int i, j, ret; + u8 b; + + // Ensure there is enough memory for the file + for (i = 0; i < strlen(buf); i++) { + if (buf[i] == '\n' && i < strlen(buf)-2) { + lcnt++; + if (buf[i+1] != '4' || buf[i+2] != '9') + ccnt++; + } + } + cfg->slot_cnt = (lcnt-RAA_DMPVR2_CFG_HEAD_LEN)/RAA_DMPVR2_CFG_SLOT_LEN; + if (cfg->slot_cnt < 1 || cfg->slot_cnt > RAA_DMPVR2_CFG_MAX_SLOT) + return -EINVAL; + cfg->cmd_cnt = ccnt; + cfg->cmds = kmalloc_array(ccnt, sizeof(struct raa_dmpvr_cfg_cmd), + GFP_KERNEL); + if (!cfg->cmds) + return -ENOMEM; + + // Parse header + for (i = 0; i < 2; i++) { + line = strsep(&buf, "\n"); + cptr = line + dsta; + for (j = 3; j >= 0; j--) { + ret = raa_dmpvr2_hextou8(cptr, &b); + if (ret) + goto parse_err; + if (i == 0) + cfg->dev_id[j] = b; + else + cfg->dev_rev[j] = b; + cptr += 2; + } + } + + // Parse cmds + i = 0; + while (line != NULL && strlen(line) > (dsta + 2)) { + if (strncmp(line, "49", 2) != 0) { + ret = raa_dmpvr2_hextou8(line+lsta, &b); + if (ret) + goto parse_err; + cfg->cmds[i].len = b - 3; + ret = raa_dmpvr2_hextou8(line+csta, &b); + if (ret) + goto parse_err; + cfg->cmds[i].cmd = b; + for (j = 0; j < cfg->cmds[i].len; j++) { + cptr = line + dsta + (2 * j); + ret = raa_dmpvr2_hextou8(cptr, &b); + if (ret) + goto parse_err; + cfg->cmds[i].data[j] = b; + } + i++; + } + line = strsep(&buf, "\n"); + } + return 0; + +parse_err: + kfree(cfg->cmds); + return ret; +} + +static int raa_dmpvr2_verify_device(struct raa_dmpvr2_ctrl *ctrl, + struct raa_dmpvr2_cfg *cfg) +{ + u8 dev_id[5]; + u8 dev_rev[5]; + int res; + + res = i2c_smbus_read_i2c_block_data(ctrl->client, PMBUS_IC_DEVICE_ID, + 5, dev_id); + if (res != 5) + return -EIO; + + res = i2c_smbus_read_i2c_block_data(ctrl->client, PMBUS_IC_DEVICE_REV, + 5, dev_rev); + if (res != 5) + return -EIO; + + return memcmp(cfg->dev_id, dev_id+1, 4) + | memcmp(cfg->dev_rev+3, dev_rev+4, 1); +} + +static int raa_dmpvr2_check_cfg(struct raa_dmpvr2_ctrl *ctrl, + struct raa_dmpvr2_cfg *cfg) +{ + u8 data[4]; + + i2c_smbus_write_word_data(ctrl->client, RAA_DMPVR2_DMA_ADDR, + RAA_DMPVR2_NVM_CNT_ADDR); + raa_dmpvr2_smbus_read32(ctrl->client, RAA_DMPVR2_DMA_SEQ, data); + if (cfg->slot_cnt > data[0]) + return -EINVAL; + return 0; +} + +static int raa_dmpvr2_send_cfg(struct raa_dmpvr2_ctrl *ctrl, + struct raa_dmpvr2_cfg *cfg) +{ + int i, status; + u16 word; + u32 dbl_word; + + for (i = 0; i < cfg->cmd_cnt; i++) { + if (cfg->cmds[i].len == 2) { + word = cfg->cmds[i].data[0] + | (cfg->cmds[i].data[1] << 8); + status = i2c_smbus_write_word_data(ctrl->client, + cfg->cmds[i].cmd, + word); + if (status < 0) + return status; + } else if (cfg->cmds[i].len == 4) { + dbl_word = cfg->cmds[i].data[0] + | (cfg->cmds[i].data[1] << 8) + | (cfg->cmds[i].data[2] << 16) + | (cfg->cmds[i].data[3] << 24); + status = raa_dmpvr2_smbus_write32(ctrl->client, + cfg->cmds[i].cmd, + dbl_word); + if (status < 0) + return status; + } else { + return -EINVAL; + } + } + + return 0; +} + +static int raa_dmpvr2_cfg_write_result(struct raa_dmpvr2_ctrl *ctrl, + struct raa_dmpvr2_cfg *cfg) +{ + u8 data[4] = {0}; + u8 data1[4]; + u8 *dptr; + unsigned long start; + int i, j, status; + + // Check programmer status + start = jiffies; + i2c_smbus_write_word_data(ctrl->client, RAA_DMPVR2_DMA_ADDR, + RAA_DMPVR2_PRGM_STATUS_ADDR); + while (data[0] == 0 && !time_after(jiffies, start + HZ + HZ)) { + raa_dmpvr2_smbus_read32(ctrl->client, RAA_DMPVR2_DMA_FIX, + data); + } + if (data[0] != 1) + return -ETIME; + + // Check bank statuses + i2c_smbus_write_word_data(ctrl->client, RAA_DMPVR2_DMA_ADDR, + RAA_DMPVR2_BANK0_STATUS_ADDR); + raa_dmpvr2_smbus_read32(ctrl->client, RAA_DMPVR2_DMA_FIX, data); + i2c_smbus_write_word_data(ctrl->client, RAA_DMPVR2_DMA_ADDR, + RAA_DMPVR2_BANK1_STATUS_ADDR); + raa_dmpvr2_smbus_read32(ctrl->client, RAA_DMPVR2_DMA_FIX, data1); + + for (i = 0; i < cfg->slot_cnt; i++) { + if (i < 8) { + j = i; + dptr = data; + } else { + j = i - 8; + dptr = data1; + } + status = (dptr[j/2] >> (4 * (j % 2))) & 0x0F; + if (status != 1) + return -EIO; + } + + return 0; +} + +static ssize_t raa_dmpvr2_write_cfg(struct raa_dmpvr2_ctrl *ctrl, + const char __user *buf, size_t len, + loff_t *ppos) +{ + char *cbuf; + int ret, status; + struct raa_dmpvr2_cfg *cfg; + + cfg = kmalloc(sizeof(*cfg), GFP_KERNEL); + if (!cfg) + return -ENOMEM; + + cbuf = kmalloc(len, GFP_KERNEL); + if (!cbuf) { + status = -ENOMEM; + goto buf_err; + } + ret = simple_write_to_buffer(cbuf, len, ppos, buf, len); + + // Parse file + status = raa_dmpvr2_parse_cfg(cbuf, cfg); + if (status) + goto parse_err; + // Verify device and file IDs/revs match + status = raa_dmpvr2_verify_device(ctrl, cfg); + if (status) + goto dev_err; + // Verify enough NVM slots available + status = raa_dmpvr2_check_cfg(ctrl, cfg); + if (status) + goto dev_err; + // Write CFG to device + status = raa_dmpvr2_send_cfg(ctrl, cfg); + if (status) + goto dev_err; + // Verify programming success + status = raa_dmpvr2_cfg_write_result(ctrl, cfg); + if (status) + goto dev_err; + // Free memory + kfree(cbuf); + kfree(cfg->cmds); + kfree(cfg); + return ret; + + // Handle Errors +dev_err: + kfree(cfg->cmds); +parse_err: + kfree(cbuf); +buf_err: + kfree(cfg); + return status; +} + +static ssize_t raa_dmpvr2_debugfs_read(struct file *file, char __user *buf, + size_t len, loff_t *ppos) +{ + int *idxp = file->private_data; + int idx = *idxp; + struct raa_dmpvr2_ctrl *ctrl = to_ctrl(idxp, idx); + + switch (idx) { + case RAA_DMPVR2_DEBUGFS_BB_R: + return raa_dmpvr2_read_black_box(ctrl, buf, len, ppos); + default: + return -EINVAL; + } +} + +static ssize_t raa_dmpvr2_debugfs_write(struct file *file, + const char __user *buf, size_t len, + loff_t *ppos) +{ + int *idxp = file->private_data; + int idx = *idxp; + struct raa_dmpvr2_ctrl *ctrl = to_ctrl(idxp, idx); + + switch (idx) { + case RAA_DMPVR2_DEBUGFS_CFG_W: + return raa_dmpvr2_write_cfg(ctrl, buf, len, ppos); + default: + return -EINVAL; + } +} + +static const struct file_operations raa_dmpvr2_debugfs_fops = { + .llseek = noop_llseek, + .read = raa_dmpvr2_debugfs_read, + .write = raa_dmpvr2_debugfs_write, + .open = simple_open, +}; + static int raa_dmpvr2_read_word_data(struct i2c_client *client, int page, int phase, int reg) { @@ -220,7 +640,11 @@ static struct pmbus_driver_info raa_dmpvr_info = { static int isl68137_probe(struct i2c_client *client, const struct i2c_device_id *id) { + int i, ret; struct pmbus_driver_info *info; + struct dentry *debugfs; + struct dentry *debug_dir; + struct raa_dmpvr2_ctrl *ctrl; info = devm_kzalloc(&client->dev, sizeof(*info), GFP_KERNEL); if (!info) @@ -262,7 +686,37 @@ static int isl68137_probe(struct i2c_client *client, return -ENODEV; } - return pmbus_do_probe(client, id, info); + // No debugfs features for Gen 1 + if (id->driver_data == raa_dmpvr1_2rail) + return pmbus_do_probe(client, id, info); + + ret = pmbus_do_probe(client, id, info); + if (ret != 0) + return ret; + + ctrl = devm_kzalloc(&client->dev, sizeof(*ctrl), GFP_KERNEL); + if (!ctrl) + return 0; + + ctrl->client = client; + debugfs = pmbus_get_debugfs_dir(client); + if (!debugfs) + return 0; + + debug_dir = debugfs_create_dir(client->name, debugfs); + if (!debug_dir) + return 0; + + for (i = 0; i < RAA_DMPVR2_DEBUGFS_NUM_ENTRIES; i++) + ctrl->debugfs_entries[i] = i; + + debugfs_create_file("write_config", 0220, debug_dir, + &ctrl->debugfs_entries[RAA_DMPVR2_DEBUGFS_CFG_W], + &raa_dmpvr2_debugfs_fops); + debugfs_create_file("read_black_box", 0440, debug_dir, + &ctrl->debugfs_entries[RAA_DMPVR2_DEBUGFS_BB_R], + &raa_dmpvr2_debugfs_fops); + return 0; } static const struct i2c_device_id raa_dmpvr_id[] = { From patchwork Wed Apr 22 17:27:48 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Grant Peltier X-Patchwork-Id: 11504327 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 2BC791575 for ; Wed, 22 Apr 2020 17:27:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 118C02137B for ; Wed, 22 Apr 2020 17:27:52 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="EtPD3itZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726505AbgDVR1v (ORCPT ); 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[99.189.78.97]) by smtp.gmail.com with ESMTPSA id x4sm366432otp.74.2020.04.22.10.27.49 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 22 Apr 2020 10:27:50 -0700 (PDT) Date: Wed, 22 Apr 2020 12:27:48 -0500 From: Grant Peltier To: linux@roeck-us.net, linux-hwmon@vger.kernel.org, linux-kernel@vger.kernel.org Cc: adam.vaughn.xh@renesas.com, grant.peltier.jg@renesas.com Subject: [PATCH v2 2/2] docs: hwmon: Update driver documentation for debugfs Message-ID: <32d05b2ebecd03cac7a704088c70a20e5a81d59f.1587572415.git.grantpeltier93@gmail.com> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-hwmon-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hwmon@vger.kernel.org Add usage details for the two new debugfs endpoints for 2nd Gen devices: read_black_box and write_config Signed-off-by: Grant Peltier --- Documentation/hwmon/isl68137.rst | 34 +++++++++++++++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/Documentation/hwmon/isl68137.rst b/Documentation/hwmon/isl68137.rst index 0e71b22047f8..c5f7b2981db6 100644 --- a/Documentation/hwmon/isl68137.rst +++ b/Documentation/hwmon/isl68137.rst @@ -423,7 +423,8 @@ Beyond the normal sysfs pmbus attributes, the driver exposes a control attribute for the ISL68137. For 2nd generation Renesas digital multiphase voltage regulators, only the -normal sysfs pmbus attributes are supported. +normal sysfs pmbus attributes are supported. However, 2nd generation devices do +have additional debugfs features which are detailed below. ISL68137 sysfs attributes ------------------------- @@ -603,3 +604,34 @@ temp[1-7]_crit_alarm Chip temperature critical high alarm temp[1-7]_max Maximum temperature temp[1-7]_max_alarm Chip temperature high alarm ======================= ========================================== + +debugfs features (Gen 2 ONLY) +----------------------------- + +If you have debugfs enabled, two file endpoints will be created under +`/sys/kernel/debug/pmbus/` when you instantiate a 2nd generation +device: `read_black_box` and `write_config`. + +`read_black_box` is a read-only file. When read, the driver will attempt to read +the contents of the device's fault recording RAM segment called "Black Box". The +RAM segment is then printed to the file as hex formatted strings. For easier +consumption, the 128-byte segment is broken up into 32 4-byte little-endian +lines (i.e. each line starts with the least significant byte). See your device's +datasheet for information regarding how to parse the data. + +.. warning:: + When using `write_config`, only use hex files as they are exported from the + Renesas Power Navigator application: + https://www.renesas.com/us/en/products/power-management/digital-power/powernavigator.html + +`write_config` is a write-only file. This endpoint expects the contents of a +configuration hex file specific to your device exactly as it is exported from +the Renesas Power Navigator application. When this endpoint is written to, the +driver will attempt to write the contents of the file down to one or more of the +device's NVM slots and will return a standard error code if any part of the +process fails. Be careful when using this feature as writing an unstable +configuration to your device may may cause it to misbehave. Each device also has +a fixed number of NVM writes allowed. Consult the datasheet for your device for +more information about NVM configuration options. Finally, note that you will +have to power cycle your device in order for NVM configuration changes to take +effect.