ARM: OMAP1: Replace PM debug create_proc_read_entry() with debugfs

There's no need to keep this entry in proc, it is PM
related debug only entry. Let's move it into debugfs.

Based on an earlier patch David Howells <dhowells@redhat.com>
to use seq_printf and to update to use create_proc_read_entry().

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

arch/arm/mach-omap1/pm.c

@@ -37,7 +37,8 @@
 
 #include <linux/suspend.h>
 #include <linux/sched.h>
-#include <linux/proc_fs.h>
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
 #include <linux/interrupt.h>
 #include <linux/sysfs.h>
 #include <linux/module.h>
@@ -422,23 +423,12 @@ void omap1_pm_suspend(void)
 		omap_rev());
 }
 
-#if defined(DEBUG) && defined(CONFIG_PROC_FS)
-static int g_read_completed;
-
+#ifdef CONFIG_DEBUG_FS
 /*
  * Read system PM registers for debugging
  */
-static int omap_pm_read_proc(
-	char *page_buffer,
-	char **my_first_byte,
-	off_t virtual_start,
-	int length,
-	int *eof,
-	void *data)
+static int omap_pm_debug_show(struct seq_file *m, void *v)
 {
-	int my_buffer_offset = 0;
-	char * const my_base = page_buffer;
-
 	ARM_SAVE(ARM_CKCTL);
 	ARM_SAVE(ARM_IDLECT1);
 	ARM_SAVE(ARM_IDLECT2);
@@ -479,10 +469,7 @@ static int omap_pm_read_proc(
 		MPUI1610_SAVE(EMIFS_CONFIG);
 	}
 
-	if (virtual_start == 0) {
-		g_read_completed = 0;
-
-		my_buffer_offset += sprintf(my_base + my_buffer_offset,
+	seq_printf(m,
 		   "ARM_CKCTL_REG:            0x%-8x     \n"
 		   "ARM_IDLECT1_REG:          0x%-8x     \n"
 		   "ARM_IDLECT2_REG:          0x%-8x     \n"
@@ -512,8 +499,8 @@ static int omap_pm_read_proc(
 		   ULPD_SHOW(ULPD_STATUS_REQ),
 		   ULPD_SHOW(ULPD_POWER_CTRL));
 
-		if (cpu_is_omap7xx()) {
-			my_buffer_offset += sprintf(my_base + my_buffer_offset,
+	if (cpu_is_omap7xx()) {
+		seq_printf(m,
 			   "MPUI7XX_CTRL_REG	     0x%-8x \n"
 			   "MPUI7XX_DSP_STATUS_REG:      0x%-8x \n"
 			   "MPUI7XX_DSP_BOOT_CONFIG_REG: 0x%-8x \n"
@@ -526,8 +513,8 @@ static int omap_pm_read_proc(
 			   MPUI7XX_SHOW(MPUI_DSP_API_CONFIG),
 			   MPUI7XX_SHOW(EMIFF_SDRAM_CONFIG),
 			   MPUI7XX_SHOW(EMIFS_CONFIG));
-		} else if (cpu_is_omap15xx()) {
-			my_buffer_offset += sprintf(my_base + my_buffer_offset,
+	} else if (cpu_is_omap15xx()) {
+		seq_printf(m,
 			   "MPUI1510_CTRL_REG             0x%-8x \n"
 			   "MPUI1510_DSP_STATUS_REG:      0x%-8x \n"
 			   "MPUI1510_DSP_BOOT_CONFIG_REG: 0x%-8x \n"
@@ -540,8 +527,8 @@ static int omap_pm_read_proc(
 			   MPUI1510_SHOW(MPUI_DSP_API_CONFIG),
 			   MPUI1510_SHOW(EMIFF_SDRAM_CONFIG),
 			   MPUI1510_SHOW(EMIFS_CONFIG));
-		} else if (cpu_is_omap16xx()) {
-			my_buffer_offset += sprintf(my_base + my_buffer_offset,
+	} else if (cpu_is_omap16xx()) {
+		seq_printf(m,
 			   "MPUI1610_CTRL_REG             0x%-8x \n"
 			   "MPUI1610_DSP_STATUS_REG:      0x%-8x \n"
 			   "MPUI1610_DSP_BOOT_CONFIG_REG: 0x%-8x \n"
@@ -554,28 +541,37 @@ static int omap_pm_read_proc(
 			   MPUI1610_SHOW(MPUI_DSP_API_CONFIG),
 			   MPUI1610_SHOW(EMIFF_SDRAM_CONFIG),
 			   MPUI1610_SHOW(EMIFS_CONFIG));
-		}
-
-		g_read_completed++;
-	} else if (g_read_completed >= 1) {
-		 *eof = 1;
-		 return 0;
 	}
-	g_read_completed++;
 
-	*my_first_byte = page_buffer;
-	return  my_buffer_offset;
+	return 0;
+}
+
+static int omap_pm_debug_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, omap_pm_debug_show,
+				&inode->i_private);
 }
 
-static void omap_pm_init_proc(void)
+static const struct file_operations omap_pm_debug_fops = {
+	.open		= omap_pm_debug_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+static void omap_pm_init_debugfs(void)
 {
-	/* XXX Appears to leak memory */
-	create_proc_read_entry("driver/omap_pm",
-			       S_IWUSR | S_IRUGO, NULL,
-			       omap_pm_read_proc, NULL);
+	struct dentry *d;
+
+	d = debugfs_create_dir("pm_debug", NULL);
+	if (!d)
+		return;
+
+	(void) debugfs_create_file("omap_pm", S_IWUSR | S_IRUGO,
+					d, NULL, &omap_pm_debug_fops);
 }
 
-#endif /* DEBUG && CONFIG_PROC_FS */
+#endif /* CONFIG_DEBUG_FS */
 
 /*
  *	omap_pm_prepare - Do preliminary suspend work.
@@ -701,8 +697,8 @@ static int __init omap_pm_init(void)
 
 	suspend_set_ops(&omap_pm_ops);
 
-#if defined(DEBUG) && defined(CONFIG_PROC_FS)
-	omap_pm_init_proc();
+#ifdef CONFIG_DEBUG_FS
+	omap_pm_init_debugfs();
 #endif
 
 #ifdef CONFIG_OMAP_32K_TIMER