ARM: S3C: CPUFREQ: Add debugfs support for cpufreq

Add debugfs support for the cpufreq driver to allow
information about the system state to be exported to
the user.

Signed-off-by: Ben Dooks <ben@simtec.co.uk>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

1 files changed, 199 insertions, 0 deletions

diff --git a/arch/arm/plat-s3c24xx/cpu-freq-debugfs.c b/arch/arm/plat-s3c24xx/cpu-freq-debugfs.c
new file mode 100644
index 00000000000..a9276667c2f
--- /dev/null
+++ b/arch/arm/plat-s3c24xx/cpu-freq-debugfs.c
@@ -0,0 +1,199 @@
+/* linux/arch/arm/plat-s3c24xx/cpu-freq-debugfs.c
+ *
+ * Copyright (c) 2009 Simtec Electronics
+ *	http://armlinux.simtec.co.uk/
+ *	Ben Dooks <ben@simtec.co.uk>
+ *
+ * S3C24XX CPU Frequency scaling - debugfs status support
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+*/
+
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/cpufreq.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include <linux/err.h>
+
+#include <plat/cpu-freq-core.h>
+
+static struct dentry *dbgfs_root;
+static struct dentry *dbgfs_file_io;
+static struct dentry *dbgfs_file_info;
+static struct dentry *dbgfs_file_board;
+
+#define print_ns(x) ((x) / 10), ((x) % 10)
+
+static void show_max(struct seq_file *seq, struct s3c_freq *f)
+{
+	seq_printf(seq, "MAX: F=%lu, H=%lu, P=%lu, A=%lu\n",
+		   f->fclk, f->hclk, f->pclk, f->armclk);
+}
+
+static int board_show(struct seq_file *seq, void *p)
+{
+	struct s3c_cpufreq_config *cfg;
+	struct s3c_cpufreq_board *brd;
+
+	cfg = s3c_cpufreq_getconfig();
+	if (!cfg) {
+		seq_printf(seq, "no configuration registered\n");
+		return 0;
+	}
+
+	brd = cfg->board;
+	if (!brd) {
+		seq_printf(seq, "no board definition set?\n");
+		return 0;
+	}
+
+	seq_printf(seq, "SDRAM refresh %u ns\n", brd->refresh);
+	seq_printf(seq, "auto_io=%u\n", brd->auto_io);
+	seq_printf(seq, "need_io=%u\n", brd->need_io);
+
+	show_max(seq, &brd->max);
+
+
+	return 0;
+}
+
+static int fops_board_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, board_show, NULL);
+}
+
+static const struct file_operations fops_board = {
+	.open		= fops_board_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+	.owner		= THIS_MODULE,
+};
+
+static int info_show(struct seq_file *seq, void *p)
+{
+	struct s3c_cpufreq_config *cfg;
+
+	cfg = s3c_cpufreq_getconfig();
+	if (!cfg) {
+		seq_printf(seq, "no configuration registered\n");
+		return 0;
+	}
+
+	seq_printf(seq, "  FCLK %ld Hz\n", cfg->freq.fclk);
+	seq_printf(seq, "  HCLK %ld Hz (%lu.%lu ns)\n",
+		   cfg->freq.hclk, print_ns(cfg->freq.hclk_tns));
+	seq_printf(seq, "  PCLK %ld Hz\n", cfg->freq.hclk);
+	seq_printf(seq, "ARMCLK %ld Hz\n", cfg->freq.armclk);
+	seq_printf(seq, "\n");
+
+	show_max(seq, &cfg->max);
+
+	seq_printf(seq, "Divisors: P=%d, H=%d, A=%d, dvs=%s\n",
+		   cfg->divs.h_divisor, cfg->divs.p_divisor,
+		   cfg->divs.arm_divisor, cfg->divs.dvs ? "on" : "off");
+	seq_printf(seq, "\n");
+
+	seq_printf(seq, "lock_pll=%u\n", cfg->lock_pll);
+
+	return 0;
+}
+
+static int fops_info_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, info_show, NULL);
+}
+
+static const struct file_operations fops_info = {
+	.open		= fops_info_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+	.owner		= THIS_MODULE,
+};
+
+static int io_show(struct seq_file *seq, void *p)
+{
+	void (*show_bank)(struct seq_file *, struct s3c_cpufreq_config *, union s3c_iobank *);
+	struct s3c_cpufreq_config *cfg;
+	struct s3c_iotimings *iot;
+	union s3c_iobank *iob;
+	int bank;
+
+	cfg = s3c_cpufreq_getconfig();
+	if (!cfg) {
+		seq_printf(seq, "no configuration registered\n");
+		return 0;
+	}
+
+	show_bank = cfg->info->debug_io_show;
+	if (!show_bank) {
+		seq_printf(seq, "no code to show bank timing\n");
+		return 0;
+	}
+
+	iot = s3c_cpufreq_getiotimings();
+	if (!iot) {
+		seq_printf(seq, "no io timings registered\n");
+		return 0;
+	}
+
+	seq_printf(seq, "hclk period is %lu.%lu ns\n", print_ns(cfg->freq.hclk_tns));
+
+	for (bank = 0; bank < MAX_BANKS; bank++) {
+		iob = &iot->bank[bank];
+
+		seq_printf(seq, "bank %d: ", bank);
+
+		if (!iob->io_2410) {
+			seq_printf(seq, "nothing set\n");
+			continue;
+		}
+
+		show_bank(seq, cfg, iob);
+	}
+
+	return 0;
+}
+
+static int fops_io_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, io_show, NULL);
+}
+
+static const struct file_operations fops_io = {
+	.open		= fops_io_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+	.owner		= THIS_MODULE,
+};
+
+
+static int __init s3c_freq_debugfs_init(void)
+{
+	dbgfs_root = debugfs_create_dir("s3c-cpufreq", NULL);
+	if (IS_ERR(dbgfs_root)) {
+		printk(KERN_ERR "%s: error creating debugfs root\n", __func__);
+		return PTR_ERR(dbgfs_root);
+	}
+
+	dbgfs_file_io = debugfs_create_file("io-timing", S_IRUGO, dbgfs_root,
+					    NULL, &fops_io);
+
+	dbgfs_file_info = debugfs_create_file("info", S_IRUGO, dbgfs_root,
+					      NULL, &fops_info);
+
+	dbgfs_file_board = debugfs_create_file("board", S_IRUGO, dbgfs_root,
+					       NULL, &fops_board);
+
+	return 0;
+}
+
+late_initcall(s3c_freq_debugfs_init);
+