From patchwork Fri Aug 12 23:25:31 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Markus Mayer X-Patchwork-Id: 9278127 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id AF07560231 for ; Fri, 12 Aug 2016 23:27:00 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9FCF828AF2 for ; Fri, 12 Aug 2016 23:27:00 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 94BAC28B27; Fri, 12 Aug 2016 23:27:00 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D92BD28AF2 for ; Fri, 12 Aug 2016 23:26:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752708AbcHLX0n (ORCPT ); Fri, 12 Aug 2016 19:26:43 -0400 Received: from mail-qk0-f169.google.com ([209.85.220.169]:35489 "EHLO mail-qk0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752127AbcHLX0m (ORCPT ); Fri, 12 Aug 2016 19:26:42 -0400 Received: by mail-qk0-f169.google.com with SMTP id v123so891080qkh.2 for ; Fri, 12 Aug 2016 16:26:41 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=B1gciAzdaZR0+mkfMA6Oz1lVpVOZHTJ7w/o8+FJhAwc=; b=DAR5aUBzzhQpm8Fa5BLIDu48IboxDf59dQcHPYHiKHTCNByBr5mLKG9FBlQap5v4MO 8xG9xlD18YrbA6Da603oEuHiLUEuRCAZkW4XqIGokt9DOOzxJ9Ra36+7r1JRbBCcFK8y sG3BUqKLKvYkxX/aqka2N1Dpxr6UWhw6vDhOE= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=B1gciAzdaZR0+mkfMA6Oz1lVpVOZHTJ7w/o8+FJhAwc=; b=Xo60VQy5Zkz3DY8TBDAMlDbeU50MTNOjrW9V53SIVetRDiJHqP67oJuGXm5uIqBAZU vb5HFH2g9VUNc6Lv5BnqWdVQfKouy3uQw9V4IN2KBc1JtVemY+8JCTP2nOUjHKJNZO1e 6XYvKF31AMZSm7EseALaDcMBBUpz4rdmYnoEAb4GyMRL8xsb6t0zU9gighX8iZScnVDw Bmu1yRYW4qEIqiv2Lwos4RAnpElyUGWVo1h4cQ6MnhQX6KS2dFzqnExzjONTNCD+sFAi xgYyKPHG8jdQBzEx0olrNg8iQ2PlwZgqezamG1RJwVM6xTfwTAbB8Z/fWujd/3Pqiu8E 8uVQ== X-Gm-Message-State: AEkooutadoJLWVY5a2HXxjSbRcxzAOc97aLjNmro3gGd2Vg1c/hxYaoo3knXEwOH/sE3owxj X-Received: by 10.55.44.134 with SMTP id s128mr10431135qkh.177.1471044400991; Fri, 12 Aug 2016 16:26:40 -0700 (PDT) Received: from lbrmn-mmayer.lab.lan ([216.31.219.19]) by smtp.gmail.com with ESMTPSA id d133sm4433489qke.40.2016.08.12.16.26.37 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 12 Aug 2016 16:26:40 -0700 (PDT) From: Markus Mayer To: Rob Herring , Mark Rutland , "Rafael J . Wysocki" , Viresh Kumar Cc: Broadcom Kernel List , Device Tree List , Power Management List , Linux Kernel Mailing List , Markus Mayer Subject: [PATCH 3/3] cpufreq: brcm-avs-cpufreq: add debugfs support Date: Fri, 12 Aug 2016 16:25:31 -0700 Message-Id: <1471044331-2480-4-git-send-email-mmayer@broadcom.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1471044331-2480-1-git-send-email-mmayer@broadcom.com> References: <1471044331-2480-1-git-send-email-mmayer@broadcom.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In order to aid debugging, we add a debugfs interface to the driver that allows direct interaction with the AVS co-processor. The debugfs interface provides a means for reading all and writing some of the mailbox registers directly from the shell prompt and enables a user to execute the communications protocol between ARM CPU and AVS CPU step-by-step. This interface should be used for debugging purposes only. Signed-off-by: Markus Mayer --- drivers/cpufreq/brcm-avs-cpufreq.c | 319 +++++++++++++++++++++++++++++++++++++ 1 file changed, 319 insertions(+) diff --git a/drivers/cpufreq/brcm-avs-cpufreq.c b/drivers/cpufreq/brcm-avs-cpufreq.c index 3fc2b30..89ff478 100644 --- a/drivers/cpufreq/brcm-avs-cpufreq.c +++ b/drivers/cpufreq/brcm-avs-cpufreq.c @@ -26,6 +26,12 @@ #include #include +#ifdef CONFIG_ARM_BRCM_AVS_CPUFREQ_DEBUG +#include +#include +#include +#endif + /* Max number of arguments AVS calls take */ #define AVS_MAX_CMD_ARGS 4 /* @@ -152,11 +158,88 @@ struct private_data { void __iomem *avs_intr_base; void __iomem *host_intr_base; struct device *dev; +#ifdef CONFIG_ARM_BRCM_AVS_CPUFREQ_DEBUG + struct dentry *debugfs; +#endif struct completion done; struct semaphore sem; struct pmap pmap; }; +#ifdef CONFIG_ARM_BRCM_AVS_CPUFREQ_DEBUG + +enum debugfs_format { + DEBUGFS_NORMAL, + DEBUGFS_FLOAT, + DEBUGFS_REV, +}; + +struct debugfs_data { + struct debugfs_entry *entry; + struct private_data *priv; +}; + +struct debugfs_entry { + char *name; + u32 offset; + fmode_t mode; + enum debugfs_format format; +}; + +#define DEBUGFS_ENTRY(name, mode, format) { \ + #name, AVS_MBOX_##name, mode, format \ +} + +/* + * These are used for debugfs only. Otherwise we use AVS_MBOX_PARAM() directly. + */ +#define AVS_MBOX_PARAM1 AVS_MBOX_PARAM(0) +#define AVS_MBOX_PARAM2 AVS_MBOX_PARAM(1) +#define AVS_MBOX_PARAM3 AVS_MBOX_PARAM(2) +#define AVS_MBOX_PARAM4 AVS_MBOX_PARAM(3) + +/* + * This table stores the name, access permissions and offset for each hardware + * register and is used to generate debugfs entries. + */ +static struct debugfs_entry debugfs_entries[] = { + DEBUGFS_ENTRY(COMMAND, S_IWUSR, DEBUGFS_NORMAL), + DEBUGFS_ENTRY(STATUS, S_IWUSR, DEBUGFS_NORMAL), + DEBUGFS_ENTRY(VOLTAGE0, 0, DEBUGFS_FLOAT), + DEBUGFS_ENTRY(TEMP0, 0, DEBUGFS_FLOAT), + DEBUGFS_ENTRY(PV0, 0, DEBUGFS_FLOAT), + DEBUGFS_ENTRY(MV0, 0, DEBUGFS_FLOAT), + DEBUGFS_ENTRY(PARAM1, S_IWUSR, DEBUGFS_NORMAL), + DEBUGFS_ENTRY(PARAM2, S_IWUSR, DEBUGFS_NORMAL), + DEBUGFS_ENTRY(PARAM3, S_IWUSR, DEBUGFS_NORMAL), + DEBUGFS_ENTRY(PARAM4, S_IWUSR, DEBUGFS_NORMAL), + DEBUGFS_ENTRY(REVISION, 0, DEBUGFS_REV), + DEBUGFS_ENTRY(PSTATE, 0, DEBUGFS_NORMAL), + DEBUGFS_ENTRY(HEARTBEAT, 0, DEBUGFS_NORMAL), + DEBUGFS_ENTRY(MAGIC, S_IWUSR, DEBUGFS_NORMAL), + DEBUGFS_ENTRY(SIGMA_HVT, 0, DEBUGFS_NORMAL), + DEBUGFS_ENTRY(SIGMA_SVT, 0, DEBUGFS_NORMAL), + DEBUGFS_ENTRY(VOLTAGE1, 0, DEBUGFS_FLOAT), + DEBUGFS_ENTRY(TEMP1, 0, DEBUGFS_FLOAT), + DEBUGFS_ENTRY(PV1, 0, DEBUGFS_FLOAT), + DEBUGFS_ENTRY(MV1, 0, DEBUGFS_FLOAT), + DEBUGFS_ENTRY(FREQUENCY, 0, DEBUGFS_NORMAL), +}; + +static int brcm_avs_target_index(struct cpufreq_policy *, unsigned int); + +static char *__strtolower(char *s) +{ + char *p; + + for (p = s; *p; p++) + *p = tolower(*p); + + return s; +} + +#endif /* CONFIG_ARM_BRCM_AVS_CPUFREQ_DEBUG */ + static void __iomem *__map_region(const char *name) { struct device_node *np; @@ -404,6 +487,239 @@ brcm_avs_get_freq_table(struct device *dev, struct private_data *priv) return table; } +#ifdef CONFIG_ARM_BRCM_AVS_CPUFREQ_DEBUG + +#define MANT(x) (unsigned int)(abs((x)) / 1000) +#define FRAC(x) (unsigned int)(abs((x)) - abs((x)) / 1000 * 1000) + +static int brcm_avs_debug_show(struct seq_file *s, void *data) +{ + struct debugfs_data *dbgfs = s->private; + void __iomem *base; + u32 val, offset; + + if (!dbgfs) { + seq_puts(s, "No device pointer\n"); + return 0; + } + + base = dbgfs->priv->base; + offset = dbgfs->entry->offset; + val = readl(base + offset); + switch (dbgfs->entry->format) { + case DEBUGFS_NORMAL: + seq_printf(s, "%u\n", val); + break; + case DEBUGFS_FLOAT: + seq_printf(s, "%d.%03d\n", MANT(val), FRAC(val)); + break; + case DEBUGFS_REV: + seq_printf(s, "%c.%c.%c.%c\n", (val >> 24 & 0xff), + (val >> 16 & 0xff), (val >> 8 & 0xff), + val & 0xff); + break; + } + seq_printf(s, "0x%08x\n", val); + + return 0; +} + +#undef MANT +#undef FRAC + +static ssize_t brcm_avs_seq_write(struct file *file, const char __user *buf, + size_t size, loff_t *ppos) +{ + struct seq_file *s = file->private_data; + struct debugfs_data *dbgfs = s->private; + struct private_data *priv = dbgfs->priv; + void __iomem *base, *avs_intr_base; + bool use_issue_command = false; + unsigned long val, offset; + char str[128]; + int ret; + char *str_ptr = str; + + if (size >= sizeof(str)) + return -E2BIG; + + memset(str, 0, sizeof(str)); + ret = copy_from_user(str, buf, size); + if (ret) + return ret; + + base = priv->base; + avs_intr_base = priv->avs_intr_base; + offset = dbgfs->entry->offset; + /* + * Special case writing to "command" entry only: if the string starts + * with a 'c', we use the driver's __issue_avs_command() function. + * Otherwise, we perform a raw write. This should allow testing of raw + * access as well as using the higher level function. (Raw access + * doesn't clear the firmware return status after issuing the command.) + */ + if (str_ptr[0] == 'c' && offset == AVS_MBOX_COMMAND) { + use_issue_command = true; + str_ptr++; + } + if (kstrtoul(str_ptr, 0, &val) != 0) + return -EINVAL; + + /* + * Setting the P-state is a special case. We need to update the CPU + * frequency we report. + */ + if (val == AVS_CMD_SET_PSTATE) { + struct cpufreq_policy *policy; + unsigned int pstate; + + policy = cpufreq_cpu_get(smp_processor_id()); + /* Read back the P-state we are about to set */ + pstate = readl(base + AVS_MBOX_PARAM(0)); + if (use_issue_command) { + ret = brcm_avs_target_index(policy, pstate); + return ret ? ret : size; + } + policy->cur = policy->freq_table[pstate].frequency; + } + + if (use_issue_command) { + ret = __issue_avs_command(priv, val, false, NULL); + } else { + /* Locking here is not perfect, but is only for debug. */ + ret = down_interruptible(&priv->sem); + if (ret) + return ret; + + writel(val, base + offset); + /* We have to wake up the firmware to process a command. */ + if (offset == AVS_MBOX_COMMAND) + writel(AVS_CPU_L2_INT_MASK, + avs_intr_base + AVS_CPU_L2_SET0); + up(&priv->sem); + } + + + return ret ? ret : size; +} + +static struct debugfs_entry *__find_debugfs_entry(const char *name) +{ + int i; + + for (i = 0; i < ARRAY_SIZE(debugfs_entries); i++) + if (strcasecmp(debugfs_entries[i].name, name) == 0) + return &debugfs_entries[i]; + + return NULL; +} + +static int brcm_avs_debug_open(struct inode *inode, struct file *file) +{ + struct debugfs_data *data; + fmode_t fmode; + int ret; + + /* + * seq_open(), which is called by single_open(), clears "write" access. + * We need write access to some files, so we preserve our access mode + * and restore it. + */ + fmode = file->f_mode; + /* + * Check access permissions even for root. We don't want to be writing + * to read-only registers. Access for regular users has already been + * checked by the VFS layer. + */ + if ((fmode & FMODE_WRITER) && !(inode->i_mode & S_IWUSR)) + return -EACCES; + + data = kmalloc(sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + /* + * We use the same file system operations for all our debug files. To + * produce specific output, we look up the file name upon opening a + * debugfs entry and map it to a memory offset. This offset is then used + * in the generic "show" function to read a specific register. + */ + data->entry = __find_debugfs_entry(file->f_path.dentry->d_iname); + data->priv = inode->i_private; + + ret = single_open(file, brcm_avs_debug_show, data); + if (ret) + kfree(data); + file->f_mode = fmode; + + return ret; +} + +static int brcm_avs_debug_release(struct inode *inode, struct file *file) +{ + struct seq_file *seq_priv = file->private_data; + struct debugfs_data *data = seq_priv->private; + + kfree(data); + return single_release(inode, file); +} + +static const struct file_operations brcm_avs_debug_ops = { + .open = brcm_avs_debug_open, + .read = seq_read, + .write = brcm_avs_seq_write, + .llseek = seq_lseek, + .release = brcm_avs_debug_release, +}; + +static void brcm_avs_cpufreq_debug_init(struct platform_device *pdev) +{ + struct private_data *priv = platform_get_drvdata(pdev); + struct dentry *dir; + int i; + + if (!priv) + return; + + dir = debugfs_create_dir(BRCM_AVS_CPUFREQ_NAME, NULL); + if (IS_ERR_OR_NULL(dir)) + return; + priv->debugfs = dir; + + for (i = 0; i < ARRAY_SIZE(debugfs_entries); i++) { + /* + * The DEBUGFS_ENTRY macro generates uppercase strings. We + * convert them to lowercase before creating the debugfs + * entries. + */ + char *entry = __strtolower(debugfs_entries[i].name); + fmode_t mode = debugfs_entries[i].mode; + + if (!debugfs_create_file(entry, S_IFREG | S_IRUGO | mode, + dir, priv, &brcm_avs_debug_ops)) { + priv->debugfs = NULL; + debugfs_remove_recursive(dir); + break; + } + } +} + +static void brcm_avs_cpufreq_debug_exit(struct platform_device *pdev) +{ + struct private_data *priv = platform_get_drvdata(pdev); + + if (priv && priv->debugfs) { + debugfs_remove_recursive(priv->debugfs); + priv->debugfs = NULL; + } +} + +#else + +static void brcm_avs_cpufreq_debug_init(struct platform_device *pdev) {} +static void brcm_avs_cpufreq_debug_exit(struct platform_device *pdev) {} + +#endif /* CONFIG_ARM_BRCM_AVS_CPUFREQ_DEBUG */ + /* * To ensure the right firmware is running we need to * - check the MAGIC matches what we expect @@ -651,12 +967,15 @@ static int brcm_avs_cpufreq_probe(struct platform_device *pdev) brcm_avs_driver.driver_data = pdev; ret = cpufreq_register_driver(&brcm_avs_driver); + if (!ret) + brcm_avs_cpufreq_debug_init(pdev); return ret; } static int brcm_avs_cpufreq_remove(struct platform_device *pdev) { + brcm_avs_cpufreq_debug_exit(pdev); return cpufreq_unregister_driver(&brcm_avs_driver); }