path: root/recipes/linux/gumstix-kernel-2.6.21/proc-gpio.patch

Index: linux-2.6.21gum/arch/arm/Kconfig
===================================================================
--- linux-2.6.21gum.orig/arch/arm/Kconfig
+++ linux-2.6.21gum/arch/arm/Kconfig
@@ -505,6 +505,8 @@ config PCI_HOST_VIA82C505
 	depends on PCI && ARCH_SHARK
 	default y
 
+source "drivers/gpio/Kconfig"
+
 source "drivers/pci/Kconfig"
 
 source "drivers/pcmcia/Kconfig"
Index: linux-2.6.21gum/drivers/Makefile
===================================================================
--- linux-2.6.21gum.orig/drivers/Makefile
+++ linux-2.6.21gum/drivers/Makefile
@@ -81,3 +81,4 @@ obj-$(CONFIG_GENERIC_TIME)	+= clocksourc
 obj-$(CONFIG_DMA_ENGINE)	+= dma/
 obj-$(CONFIG_HID)		+= hid/
 obj-$(CONFIG_PPC_PS3)		+= ps3/
+obj-$(CONFIG_PROC_GPIO)		+= gpio/
Index: linux-2.6.21gum/drivers/gpio/Kconfig
===================================================================
--- /dev/null
+++ linux-2.6.21gum/drivers/gpio/Kconfig
@@ -0,0 +1,12 @@
+config PROC_GPIO
+	tristate "GPIO /proc interface"
+	depends on PXA25x || PXA27x
+	help
+	  This enables an interface under /proc/gpio which allows reading or setting
+	  of any GPIO, and also changing the GPIO alt function mode of any line.
+
+config PROC_GPIO_DEBUG
+	boolean "Enable /proc/gpio debug logging"
+	depends on PROC_GPIO
+	help
+	  This enables printk logging of activity done through /proc/gpio
Index: linux-2.6.21gum/drivers/gpio/Makefile
===================================================================
--- /dev/null
+++ linux-2.6.21gum/drivers/gpio/Makefile
@@ -0,0 +1,3 @@
+# Expose GPIOs under /proc
+obj-$(CONFIG_PROC_GPIO)			+= proc_gpio.o
+
Index: linux-2.6.21gum/drivers/gpio/proc_gpio.c
===================================================================
--- /dev/null
+++ linux-2.6.21gum/drivers/gpio/proc_gpio.c
@@ -0,0 +1,296 @@
+/*
+ *
+ *  PXA25x GPIOs exposed under /proc for reading and writing
+ *  They will show up under /proc/gpio/NN
+ *
+ *  Based on patch 1773/1 in the arm kernel patch repository at arm.linux.co.uk
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/string.h>
+#include <linux/ctype.h>
+
+#include <asm/hardware.h>
+#include <asm/arch/pxa-regs.h>
+#include <asm/uaccess.h>
+
+static struct proc_dir_entry *proc_gpio_parent;
+static struct proc_dir_entry *proc_gpios[PXA_LAST_GPIO + 1];
+
+typedef struct
+{
+	int	gpio;
+	char    name[32];
+} gpio_summary_type;
+
+static gpio_summary_type gpio_summaries[PXA_LAST_GPIO + 1];
+
+static int proc_gpio_write(struct file *file, const char __user *buf,
+                           unsigned long count, void *data)
+{
+	char *cur, lbuf[count + 1];
+	gpio_summary_type *summary = data;
+	u32 altfn, direction, setclear, gafr;
+
+	if (!capable(CAP_SYS_ADMIN))
+		return -EACCES;
+
+	memset(lbuf, 0, count + 1);
+
+	if (copy_from_user(lbuf, buf, count))
+		return -EFAULT;
+
+	cur = lbuf;
+
+	// Initialize to current state
+	altfn = ((GAFR(summary->gpio) >> ((summary->gpio & 0x0f) << 0x01)) & 0x03);
+	direction = GPDR(summary->gpio) & GPIO_bit(summary->gpio);
+	setclear = GPLR(summary->gpio) & GPIO_bit(summary->gpio);
+	while(1)
+	{
+		// We accept options: {GPIO|AF1|AF2|AF3}, {set|clear}, {in|out}
+		// Anything else is an error
+		while(cur[0] && (isspace(cur[0]) || ispunct(cur[0]))) cur = &(cur[1]);
+
+		if('\0' == cur[0]) break;
+
+		// Ok, so now we're pointing at the start of something
+		switch(cur[0])
+		{
+			case 'G':
+				// Check that next is "PIO" -- '\0' will cause safe short-circuit if end of buf
+				if(!(cur[1] == 'P' && cur[2] == 'I' && cur[3] == 'O')) goto parse_error;
+				// Ok, so set this GPIO to GPIO (non-ALT) function
+				altfn = 0;
+				cur = &(cur[4]);
+				break;
+			case 'A':
+				if(!(cur[1] == 'F' && cur[2] >= '1' && cur[2] <= '3')) goto parse_error;
+				altfn = cur[2] - '0';
+				cur = &(cur[3]);
+				break;
+			case 's':
+				if(!(cur[1] == 'e' && cur[2] == 't')) goto parse_error;
+				setclear = 1;
+				cur = &(cur[3]);
+				break;
+			case 'c':
+				if(!(cur[1] == 'l' && cur[2] == 'e' && cur[3] == 'a' && cur[4] == 'r')) goto parse_error;
+				setclear = 0;
+				cur = &(cur[5]);
+				break;
+			case 'i':
+				if(!(cur[1] == 'n')) goto parse_error;
+				direction = 0;
+				cur = &(cur[2]);
+				break;
+			case 'o':
+				if(!(cur[1] == 'u' && cur[2] == 't')) goto parse_error;
+				direction = 1;
+				cur = &(cur[3]);
+				break;
+			default: goto parse_error;
+		}
+	}
+	// Ok, now set gpio mode and value
+	if(direction)
+		GPDR(summary->gpio) |= GPIO_bit(summary->gpio);
+	else
+		GPDR(summary->gpio) &= ~GPIO_bit(summary->gpio);
+
+	gafr = GAFR(summary->gpio) & ~(0x3 << (((summary->gpio) & 0xf)*2));
+	GAFR(summary->gpio) = gafr |  (altfn  << (((summary->gpio) & 0xf)*2));
+
+	if(direction && !altfn)
+	{
+		if(setclear) GPSR(summary->gpio) = GPIO_bit(summary->gpio);
+		else GPCR(summary->gpio) = GPIO_bit(summary->gpio);
+	}
+
+#ifdef CONFIG_PROC_GPIO_DEBUG
+	printk(KERN_INFO "Set (%s,%s,%s) via /proc/gpio/%s\n",altfn ? (altfn == 1 ? "AF1" : (altfn == 2 ? "AF2" : "AF3")) : "GPIO",
+				direction ? "out" : "in",
+				setclear ? "set" : "clear",
+				summary->name);
+#endif
+
+	return count;
+
+parse_error:
+	printk(KERN_CRIT "Parse error: Expect \"[GPIO|AF1|AF2|AF3]|[set|clear]|[in|out] ...\"\n");
+	return -EINVAL;
+}
+
+static int proc_gpio_read(char *page, char **start, off_t off,
+			int count, int *eof, void *data)
+{
+	char *p = page;
+	gpio_summary_type *summary = data;
+	int len, i, af;
+	i = summary->gpio;
+
+	p += sprintf(p, "%d\t%s\t%s\t%s\n", i,
+			(af = ((GAFR(i) >> ((i & 0x0f) << 0x01)) & 0x03)) ? (af == 1 ? "AF1" : (af == 2 ? "AF2" : "AF3")) : "GPIO",
+			(GPDR(i) & GPIO_bit(i)) ? "out" : "in",
+			(GPLR(i) & GPIO_bit(i)) ? "set" : "clear");
+
+	len = (p - page) - off;
+
+	if(len < 0)
+	{
+		len = 0;
+	}
+
+	*eof = (len <= count) ? 1 : 0;
+	*start = page + off;
+
+	return len;
+}
+
+
+#ifdef CONFIG_PXA25x
+static const char const *GAFR_DESC[] = { "GAFR0_L", "GAFR0_U", "GAFR1_L", "GAFR1_U", "GAFR2_L", "GAFR2_U" };
+#elif defined(CONFIG_PXA27x)
+static const char const *GAFR_DESC[] = { "GAFR0_L", "GAFR0_U", "GAFR1_L", "GAFR1_U", "GAFR2_L", "GAFR2_U", "GAFR3_L", "GAFR3_U" };
+#endif
+
+static int proc_gafr_read(char *page, char **start, off_t off,
+			int count, int *eof, void *data)
+{
+	char *p = page;
+	int i, len;
+
+	for(i=0; i<ARRAY_SIZE(GAFR_DESC); i++)
+	{
+		p += sprintf(p, "%s: %08x\n", GAFR_DESC[i], GAFR(i*16));
+	}
+
+	len = (p - page) - off;
+
+	if(len < 0)
+	{
+		len = 0;
+	}
+
+	*eof = (len <= count) ? 1 : 0;
+	*start = page + off;
+
+	return len;
+}
+
+static int proc_gpdr_read(char *page, char **start, off_t off,
+			int count, int *eof, void *data)
+{
+	char *p = page;
+	int i, len;
+
+	for(i=0; i<=2; i++)
+	{
+		p += sprintf(p, "GPDR%d: %08x\n", i, GPDR(i * 32));
+	}
+
+	len = (p - page) - off;
+
+	if(len < 0)
+	{
+		len = 0;
+	}
+
+	*eof = (len <= count) ? 1 : 0;
+	*start = page + off;
+
+	return len;
+}
+
+static int proc_gplr_read(char *page, char **start, off_t off,
+			int count, int *eof, void *data)
+{
+	char *p = page;
+	int i, len;
+
+	for(i=0; i<=2; i++)
+	{
+		p += sprintf(p, "GPLR%d: %08x\n", i, GPLR(i * 32));
+	}
+
+	len = (p - page) - off;
+
+	if(len < 0)
+	{
+		len = 0;
+	}
+
+	*eof = (len <= count) ? 1 : 0;
+	*start = page + off;
+
+	return len;
+}
+
+static int __init gpio_init(void)
+{
+	int i;
+
+  proc_gpio_parent = NULL;
+  for (proc_gpio_parent = proc_root.subdir; proc_gpio_parent; proc_gpio_parent = proc_gpio_parent->next) {
+    if (( proc_gpio_parent->namelen == 4 ) && ( memcmp(proc_gpio_parent->name, "gpio", 4 ) == 0 ))
+      break;
+  }
+
+  // proc_gpio_parent will be non-NULL if the directory already exists
+
+  if (!proc_gpio_parent) {
+       proc_gpio_parent = proc_gpio_parent = create_proc_entry("gpio", S_IFDIR | S_IRUGO | S_IXUGO, NULL);
+  }
+
+ 	if(!proc_gpio_parent) return 0;
+
+	for(i=0; i < (PXA_LAST_GPIO+1); i++)
+	{
+		gpio_summaries[i].gpio = i;
+		sprintf(gpio_summaries[i].name, "GPIO%d", i);
+		proc_gpios[i] = create_proc_entry(gpio_summaries[i].name, 0644, proc_gpio_parent);
+		if(proc_gpios[i])
+		{
+			proc_gpios[i]->data = &gpio_summaries[i];
+			proc_gpios[i]->read_proc = proc_gpio_read;
+			proc_gpios[i]->write_proc = proc_gpio_write;
+		}
+	}
+
+	create_proc_read_entry("GAFR", 0444, proc_gpio_parent, proc_gafr_read, NULL);
+	create_proc_read_entry("GPDR", 0444, proc_gpio_parent, proc_gpdr_read, NULL);
+	create_proc_read_entry("GPLR", 0444, proc_gpio_parent, proc_gplr_read, NULL);
+
+	return 0;
+}
+
+static void gpio_exit(void)
+{
+	int i;
+
+	remove_proc_entry("GAFR", proc_gpio_parent);
+	remove_proc_entry("GPDR", proc_gpio_parent);
+	remove_proc_entry("GPLR", proc_gpio_parent);
+
+	for(i=0; i < (PXA_LAST_GPIO+1); i++)
+	{
+		if(proc_gpios[i]) remove_proc_entry(gpio_summaries[i].name, proc_gpio_parent);
+	}
+
+  if (proc_gpio_parent)
+  {
+    if (!proc_gpio_parent->subdir)
+    {
+      // Only remove /proc/gpio if it's empty.
+      remove_proc_entry( "gpio", NULL );
+    }
+  }
+
+}
+
+module_init(gpio_init);
+module_exit(gpio_exit);
+MODULE_LICENSE("GPL");