[PATCH] chardev: GPIO for SCx200 & PC-8736x: use dev_dbg in common module

Use of dev_dbg() and friends is considered good practice.  dev_dbg() needs a
struct device *devp, but nsc_gpio is only a helper module, so it doesnt
have/need its own.  To provide devp to the user-modules (scx200 & pc8736x
_gpio), we add it to the vtable, and set it during init.

Also squeeze nsc_gpio_dump()'s format a little.

[  199.259879]  pc8736x_gpio.0: io09: 0x0044 TS OD PUE  EDGE LO DEBOUNCE
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

drivers/char/nsc_gpio.c

@@ -14,22 +14,27 @@
 #include <linux/kernel.h>
 #include <linux/init.h>
 #include <linux/nsc_gpio.h>
+#include <linux/platform_device.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
 
 #define NAME "nsc_gpio"
 
-void nsc_gpio_dump(unsigned index, u32 config)
+void nsc_gpio_dump(struct nsc_gpio_ops *amp, unsigned index)
 {
-	printk(KERN_INFO NAME ": GPIO-%02u: 0x%08lx %s %s %s %s %s %s %s\n",
-	       index, (unsigned long)config,
-	       (config & 1) ? "OE" : "TS",      /* output-enabled/tristate */
-	       (config & 2) ? "PP" : "OD",      /* push pull / open drain */
-	       (config & 4) ? "PUE" : "PUD",    /* pull up enabled/disabled */
-	       (config & 8) ? "LOCKED" : "",    /* locked / unlocked */
-	       (config & 16) ? "LEVEL" : "EDGE",/* level/edge input */
-	       (config & 32) ? "HI" : "LO",     /* trigger on rise/fall edge */
-	       (config & 64) ? "DEBOUNCE" : "");        /* debounce */
+	/* retrieve current config w/o changing it */
+	u32 config = amp->gpio_config(index, ~0, 0);
+
+	/* user requested via 'v' command, so its INFO */
+	dev_info(amp->dev, "io%02u: 0x%04x %s %s %s %s %s %s %s\n",
+		 index, config,
+		 (config & 1) ? "OE" : "TS",      /* output-enabled/tristate */
+		 (config & 2) ? "PP" : "OD",      /* push pull / open drain */
+		 (config & 4) ? "PUE" : "PUD",    /* pull up enabled/disabled */
+		 (config & 8) ? "LOCKED" : "",    /* locked / unlocked */
+		 (config & 16) ? "LEVEL" : "EDGE",/* level/edge input */
+		 (config & 32) ? "HI" : "LO",     /* trigger on rise/fall edge */
+		 (config & 64) ? "DEBOUNCE" : "");        /* debounce */
 }
 
 ssize_t nsc_gpio_write(struct file *file, const char __user *data,
@@ -37,6 +42,7 @@ ssize_t nsc_gpio_write(struct file *file, const char __user *data,
 {
 	unsigned m = iminor(file->f_dentry->d_inode);
 	struct nsc_gpio_ops *amp = file->private_data;
+	struct device *dev = amp->dev;
 	size_t i;
 	int err = 0;
 
@@ -52,42 +58,41 @@ ssize_t nsc_gpio_write(struct file *file, const char __user *data,
 			amp->gpio_set(m, 1);
 			break;
 		case 'O':
-			printk(KERN_INFO NAME ": GPIO%d output enabled\n", m);
+			dev_dbg(dev, "GPIO%d output enabled\n", m);
 			amp->gpio_config(m, ~1, 1);
 			break;
 		case 'o':
-			printk(KERN_INFO NAME ": GPIO%d output disabled\n", m);
+			dev_dbg(dev, "GPIO%d output disabled\n", m);
 			amp->gpio_config(m, ~1, 0);
 			break;
 		case 'T':
-			printk(KERN_INFO NAME ": GPIO%d output is push pull\n",
+			dev_dbg(dev, "GPIO%d output is push pull\n",
 			       m);
 			amp->gpio_config(m, ~2, 2);
 			break;
 		case 't':
-			printk(KERN_INFO NAME ": GPIO%d output is open drain\n",
+			dev_dbg(dev, "GPIO%d output is open drain\n",
 			       m);
 			amp->gpio_config(m, ~2, 0);
 			break;
 		case 'P':
-			printk(KERN_INFO NAME ": GPIO%d pull up enabled\n", m);
+			dev_dbg(dev, "GPIO%d pull up enabled\n", m);
 			amp->gpio_config(m, ~4, 4);
 			break;
 		case 'p':
-			printk(KERN_INFO NAME ": GPIO%d pull up disabled\n", m);
+			dev_dbg(dev, "GPIO%d pull up disabled\n", m);
 			amp->gpio_config(m, ~4, 0);
 			break;
 		case 'v':
 			/* View Current pin settings */
-			amp->gpio_dump(m);
+			amp->gpio_dump(amp, m);
 			break;
 		case '\n':
 			/* end of settings string, do nothing */
 			break;
 		default:
-			printk(KERN_ERR NAME
-			       ": GPIO-%2d bad setting: chr<0x%2x>\n", m,
-			       (int)c);
+			dev_err(dev, "io%2d bad setting: chr<0x%2x>\n",
+				m, (int)c);
 			err++;
 		}
 	}

drivers/char/pc8736x_gpio.c

@@ -207,8 +207,6 @@ static void pc8736x_gpio_change(unsigned index)
 	pc8736x_gpio_set(index, !pc8736x_gpio_get(index));
 }
 
-extern void nsc_gpio_dump(unsigned iminor);
-
 static struct nsc_gpio_ops pc8736x_access = {
 	.owner		= THIS_MODULE,
 	.gpio_config	= pc8736x_gpio_configure,
@@ -260,6 +258,7 @@ static int __init pc8736x_gpio_init(void)
 		dev_err(&pdev->dev, "no device found\n");
 		goto undo_platform_dev_add;
 	}
+	pc8736x_access.dev = &pdev->dev;
 
 	/* Verify that chip and it's GPIO unit are both enabled.
 	   My BIOS does this, so I take minimum action here

drivers/char/scx200_gpio.c

@@ -35,14 +35,6 @@ static int major = 0;		/* default to dynamic major */
 module_param(major, int, 0);
 MODULE_PARM_DESC(major, "Major device number");
 
-extern void nsc_gpio_dump(unsigned index);
-
-extern ssize_t nsc_gpio_write(struct file *file, const char __user *data,
-			      size_t len, loff_t *ppos);
-
-extern ssize_t nsc_gpio_read(struct file *file, char __user *buf,
-			     size_t len, loff_t *ppos);
-
 struct nsc_gpio_ops scx200_access = {
 	.owner		= THIS_MODULE,
 	.gpio_config	= scx200_gpio_configure,
@@ -101,6 +93,9 @@ static int __init scx200_gpio_init(void)
 	if (rc)
 		goto undo_malloc;
 
+	/* nsc_gpio uses dev_dbg(), so needs this */
+	scx200_access.dev = &pdev->dev;
+
 	if (major)
 		rc = register_chrdev_region(dev, num_pins, "scx200_gpio");
 	else {

include/linux/nsc_gpio.h

@@ -22,13 +22,14 @@
 struct nsc_gpio_ops {
 	struct module*	owner;
 	u32	(*gpio_config)	(unsigned iminor, u32 mask, u32 bits);
-	void	(*gpio_dump)	(unsigned iminor);
+	void	(*gpio_dump)	(struct nsc_gpio_ops *amp, unsigned iminor);
 	int	(*gpio_get)	(unsigned iminor);
 	void	(*gpio_set)	(unsigned iminor, int state);
 	void	(*gpio_set_high)(unsigned iminor);
 	void	(*gpio_set_low)	(unsigned iminor);
 	void	(*gpio_change)	(unsigned iminor);
 	int	(*gpio_current)	(unsigned iminor);
+	struct device*	dev;	/* for dev_dbg() support, set in init  */
 };
 
 extern ssize_t nsc_gpio_write(struct file *file, const char __user *data,
@@ -36,3 +37,6 @@ extern ssize_t nsc_gpio_write(struct file *file, const char __user *data,
 
 extern ssize_t nsc_gpio_read(struct file *file, char __user *buf,
 			     size_t len, loff_t *ppos);
+
+extern void nsc_gpio_dump(struct nsc_gpio_ops *amp, unsigned index);
+