Message-Id: <20180418155643.36464-2-code@mmayer.net>
Date:   Wed, 18 Apr 2018 08:56:42 -0700
From:   Markus Mayer <code@...yer.net>
To:     Viresh Kumar <viresh.kumar@...aro.org>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Brian Norris <computersforpeace@...il.com>,
        Gregory Fong <gregory.0xf0@...il.com>,
        Florian Fainelli <f.fainelli@...il.com>
Cc:     Markus Mayer <mmayer@...adcom.com>,
        Broadcom Kernel List <bcm-kernel-feedback-list@...adcom.com>,
        Power Management List <linux-pm@...r.kernel.org>,
        ARM Kernel List <linux-arm-kernel@...ts.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: [PATCH 1/2] cpufreq: brcmstb-avs-cpufreq: remove development debug support

From: Markus Mayer <mmayer@...adcom.com>

This debug code was helpful while developing the driver, but it isn't
being used for anything anymore.

Signed-off-by: Markus Mayer <mmayer@...adcom.com>
---
 drivers/cpufreq/Kconfig.arm           |  10 --
 drivers/cpufreq/brcmstb-avs-cpufreq.c | 323 +---------------------------------
 2 files changed, 1 insertion(+), 332 deletions(-)

diff --git a/drivers/cpufreq/Kconfig.arm b/drivers/cpufreq/Kconfig.arm
index 7f56fe5183f2..de55c7d57438 100644
--- a/drivers/cpufreq/Kconfig.arm
+++ b/drivers/cpufreq/Kconfig.arm
@@ -71,16 +71,6 @@ config ARM_BRCMSTB_AVS_CPUFREQ
 
 	  Say Y, if you have a Broadcom SoC with AVS support for DFS or DVFS.
 
-config ARM_BRCMSTB_AVS_CPUFREQ_DEBUG
-	bool "Broadcom STB AVS CPUfreq driver sysfs debug capability"
-	depends on ARM_BRCMSTB_AVS_CPUFREQ
-	help
-	  Enabling this option turns on debug support via sysfs under
-	  /sys/kernel/debug/brcmstb-avs-cpufreq. It is possible to read all and
-	  write some AVS mailbox registers through sysfs entries.
-
-	  If in doubt, say N.
-
 config ARM_EXYNOS5440_CPUFREQ
 	tristate "SAMSUNG EXYNOS5440"
 	depends on SOC_EXYNOS5440
diff --git a/drivers/cpufreq/brcmstb-avs-cpufreq.c b/drivers/cpufreq/brcmstb-avs-cpufreq.c
index 6cdac1aaf23c..b07559b9ed99 100644
--- a/drivers/cpufreq/brcmstb-avs-cpufreq.c
+++ b/drivers/cpufreq/brcmstb-avs-cpufreq.c
@@ -49,13 +49,6 @@
 #include <linux/platform_device.h>
 #include <linux/semaphore.h>
 
-#ifdef CONFIG_ARM_BRCMSTB_AVS_CPUFREQ_DEBUG
-#include <linux/ctype.h>
-#include <linux/debugfs.h>
-#include <linux/slab.h>
-#include <linux/uaccess.h>
-#endif
-
 /* Max number of arguments AVS calls take */
 #define AVS_MAX_CMD_ARGS	4
 /*
@@ -182,88 +175,11 @@ struct private_data {
 	void __iomem *base;
 	void __iomem *avs_intr_base;
 	struct device *dev;
-#ifdef CONFIG_ARM_BRCMSTB_AVS_CPUFREQ_DEBUG
-	struct dentry *debugfs;
-#endif
 	struct completion done;
 	struct semaphore sem;
 	struct pmap pmap;
 };
 
-#ifdef CONFIG_ARM_BRCMSTB_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_BRCMSTB_AVS_CPUFREQ_DEBUG */
-
 static void __iomem *__map_region(const char *name)
 {
 	struct device_node *np;
@@ -516,238 +432,6 @@ brcm_avs_get_freq_table(struct device *dev, struct private_data *priv)
 	return table;
 }
 
-#ifdef CONFIG_ARM_BRCMSTB_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_BRCMSTB_AVS_CPUFREQ_DEBUG */
-
 /*
  * To ensure the right firmware is running we need to
  *    - check the MAGIC matches what we expect
@@ -1016,11 +700,8 @@ static int brcm_avs_cpufreq_probe(struct platform_device *pdev)
 		return ret;
 
 	brcm_avs_driver.driver_data = pdev;
-	ret = cpufreq_register_driver(&brcm_avs_driver);
-	if (!ret)
-		brcm_avs_cpufreq_debug_init(pdev);
 
-	return ret;
+	return cpufreq_register_driver(&brcm_avs_driver);
 }
 
 static int brcm_avs_cpufreq_remove(struct platform_device *pdev)
@@ -1032,8 +713,6 @@ static int brcm_avs_cpufreq_remove(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	brcm_avs_cpufreq_debug_exit(pdev);
-
 	priv = platform_get_drvdata(pdev);
 	iounmap(priv->base);
 	iounmap(priv->avs_intr_base);
-- 
2.7.4

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