[PATCH] chardev: GPIO for SCx200 & PC-8736x: add new pc8736x_gpio module (681a3e7d) · Commits · e / devices / android_kernel_fairphone_FP3

drivers/char/Makefile

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Original line number	Diff line number	Diff line
		@@ -81,7 +81,7 @@ obj-$(CONFIG_COBALT_LCD) += lcd.o
		obj-$(CONFIG_PPDEV) += ppdev.o
		obj-$(CONFIG_NWBUTTON) += nwbutton.o
		obj-$(CONFIG_NWFLASH) += nwflash.o
		obj-$(CONFIG_SCx200_GPIO) += scx200_gpio.o nsc_gpio.o
		obj-$(CONFIG_SCx200_GPIO) += scx200_gpio.o nsc_gpio.o pc8736x_gpio.o
		obj-$(CONFIG_CS5535_GPIO) += cs5535_gpio.o
		obj-$(CONFIG_GPIO_VR41XX) += vr41xx_giu.o
		obj-$(CONFIG_TANBAC_TB0219) += tb0219.o

drivers/char/nsc_gpio.c

+0 −1

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		@@ -77,7 +77,6 @@ ssize_t nsc_gpio_write(struct file file, const char __user data,
		printk(KERN_INFO NAME ": GPIO%d pull up disabled\n", m);
		amp->gpio_config(m, ~4, 0);
		break;

		case 'v':
		/* View Current pin settings */
		amp->gpio_dump(m);

drivers/char/pc8736x_gpio.c

0 → 100644

+296 −0

Original line number	Diff line number	Diff line
		/* linux/drivers/char/pc8736x_gpio.c

		National Semiconductor PC8736x GPIO driver. Allows a user space
		process to play with the GPIO pins.

		Copyright (c) 2005 Jim Cromie <jim.cromie@gmail.com>

		adapted from linux/drivers/char/scx200_gpio.c
		Copyright (c) 2001,2002 Christer Weinigel <wingel@nano-system.com>,
		*/

		#include <linux/config.h>
		#include <linux/fs.h>
		#include <linux/module.h>
		#include <linux/errno.h>
		#include <linux/kernel.h>
		#include <linux/init.h>
		#include <linux/ioport.h>
		#include <linux/nsc_gpio.h>
		#include <asm/uaccess.h>
		#include <asm/io.h>

		#define NAME "pc8736x_gpio"

		MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>");
		MODULE_DESCRIPTION("NatSemi SCx200 GPIO Pin Driver");
		MODULE_LICENSE("GPL");

		static int major; /* default to dynamic major */
		module_param(major, int, 0);
		MODULE_PARM_DESC(major, "Major device number");

		static DEFINE_SPINLOCK(pc8736x_gpio_config_lock);
		static unsigned pc8736x_gpio_base;

		#define SIO_BASE1 0x2E /* 1st command-reg to check */
		#define SIO_BASE2 0x4E /* alt command-reg to check */
		#define SIO_BASE_OFFSET 0x20

		#define SIO_SID 0x20 /* SuperI/O ID Register */
		#define SIO_SID_VALUE 0xe9 /* Expected value in SuperI/O ID Register */

		#define SIO_CF1 0x21 /* chip config, bit0 is chip enable */

		#define SIO_UNIT_SEL 0x7 /* unit select reg */
		#define SIO_UNIT_ACT 0x30 /* unit enable */
		#define SIO_GPIO_UNIT 0x7 /* unit number of GPIO */
		#define SIO_VLM_UNIT 0x0D
		#define SIO_TMS_UNIT 0x0E

		/* config-space addrs to read/write each unit's runtime addr */
		#define SIO_BASE_HADDR 0x60
		#define SIO_BASE_LADDR 0x61

		/* GPIO config-space pin-control addresses */
		#define SIO_GPIO_PIN_SELECT 0xF0
		#define SIO_GPIO_PIN_CONFIG 0xF1
		#define SIO_GPIO_PIN_EVENT 0xF2

		static unsigned char superio_cmd = 0;
		static unsigned char selected_device = 0xFF; /* bogus start val */

		/* GPIO port runtime access, functionality */
		static int port_offset[] = { 0, 4, 8, 10 }; /* non-uniform offsets ! */
		/* static int event_capable[] = { 1, 1, 0, 0 }; ports 2,3 are hobbled */

		#define PORT_OUT 0
		#define PORT_IN 1
		#define PORT_EVT_EN 2
		#define PORT_EVT_STST 3

		static inline void superio_outb(int addr, int val)
		{
		outb_p(addr, superio_cmd);
		outb_p(val, superio_cmd + 1);
		}

		static inline int superio_inb(int addr)
		{
		outb_p(addr, superio_cmd);
		return inb_p(superio_cmd + 1);
		}

		static int pc8736x_superio_present(void)
		{
		/* try the 2 possible values, read a hardware reg to verify */
		superio_cmd = SIO_BASE1;
		if (superio_inb(SIO_SID) == SIO_SID_VALUE)
		return superio_cmd;

		superio_cmd = SIO_BASE2;
		if (superio_inb(SIO_SID) == SIO_SID_VALUE)
		return superio_cmd;

		return 0;
		}

		static void device_select(unsigned devldn)
		{
		superio_outb(SIO_UNIT_SEL, devldn);
		selected_device = devldn;
		}

		static void select_pin(unsigned iminor)
		{
		/* select GPIO port/pin from device minor number */
		device_select(SIO_GPIO_UNIT);
		superio_outb(SIO_GPIO_PIN_SELECT,
		((iminor << 1) & 0xF0) \| (iminor & 0x7));
		}

		static inline u32 pc8736x_gpio_configure_fn(unsigned index, u32 mask, u32 bits,
		u32 func_slct)
		{
		u32 config, new_config;
		unsigned long flags;

		spin_lock_irqsave(&pc8736x_gpio_config_lock, flags);

		device_select(SIO_GPIO_UNIT);
		select_pin(index);

		/* read current config value */
		config = superio_inb(func_slct);

		/* set new config */
		new_config = (config & mask) \| bits;
		superio_outb(func_slct, new_config);

		spin_unlock_irqrestore(&pc8736x_gpio_config_lock, flags);

		return config;
		}

		static u32 pc8736x_gpio_configure(unsigned index, u32 mask, u32 bits)
		{
		return pc8736x_gpio_configure_fn(index, mask, bits,
		SIO_GPIO_PIN_CONFIG);
		}

		static int pc8736x_gpio_get(unsigned minor)
		{
		int port, bit, val;

		port = minor >> 3;
		bit = minor & 7;
		val = inb_p(pc8736x_gpio_base + port_offset[port] + PORT_IN);
		val >>= bit;
		val &= 1;

		printk(KERN_INFO NAME ": _gpio_get(%d from %x bit %d) == val %d\n",
		minor, pc8736x_gpio_base + port_offset[port] + PORT_IN, bit,
		val);

		return val;
		}

		static void pc8736x_gpio_set(unsigned minor, int val)
		{
		int port, bit, curval;

		minor &= 0x1f;
		port = minor >> 3;
		bit = minor & 7;
		curval = inb_p(pc8736x_gpio_base + port_offset[port] + PORT_OUT);

		printk(KERN_INFO NAME
		": addr:%x cur:%x bit-pos:%d cur-bit:%x + new:%d -> bit-new:%d\n",
		pc8736x_gpio_base + port_offset[port] + PORT_OUT,
		curval, bit, (curval & ~(1 << bit)), val, (val << bit));

		val = (curval & ~(1 << bit)) \| (val << bit);

		printk(KERN_INFO NAME ": gpio_set(minor:%d port:%d bit:%d"
		") %2x -> %2x\n", minor, port, bit, curval, val);

		outb_p(val, pc8736x_gpio_base + port_offset[port] + PORT_OUT);

		curval = inb_p(pc8736x_gpio_base + port_offset[port] + PORT_OUT);
		val = inb_p(pc8736x_gpio_base + port_offset[port] + PORT_IN);

		printk(KERN_INFO NAME ": wrote %x, read: %x\n", curval, val);
		}

		static void pc8736x_gpio_set_high(unsigned index)
		{
		pc8736x_gpio_set(index, 1);
		}

		static void pc8736x_gpio_set_low(unsigned index)
		{
		pc8736x_gpio_set(index, 0);
		}

		static int pc8736x_gpio_current(unsigned index)
		{
		printk(KERN_WARNING NAME ": pc8736x_gpio_current unimplemented\n");
		return 0;
		}

		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,
		.gpio_dump = nsc_gpio_dump,
		.gpio_get = pc8736x_gpio_get,
		.gpio_set = pc8736x_gpio_set,
		.gpio_set_high = pc8736x_gpio_set_high,
		.gpio_set_low = pc8736x_gpio_set_low,
		.gpio_change = pc8736x_gpio_change,
		.gpio_current = pc8736x_gpio_current
		};

		static int pc8736x_gpio_open(struct inode inode, struct file file)
		{
		unsigned m = iminor(inode);
		file->private_data = &pc8736x_access;

		printk(KERN_NOTICE NAME " open %d\n", m);

		if (m > 63)
		return -EINVAL;
		return nonseekable_open(inode, file);
		}

		static struct file_operations pc8736x_gpio_fops = {
		.owner = THIS_MODULE,
		.open = pc8736x_gpio_open,
		.write = nsc_gpio_write,
		.read = nsc_gpio_read,
		};

		static int __init pc8736x_gpio_init(void)
		{
		int r, rc;

		printk(KERN_DEBUG NAME " initializing\n");

		if (!pc8736x_superio_present()) {
		printk(KERN_ERR NAME ": no device found\n");
		return -ENODEV;
		}

		/* Verify that chip and it's GPIO unit are both enabled.
		My BIOS does this, so I take minimum action here
		*/
		rc = superio_inb(SIO_CF1);
		if (!(rc & 0x01)) {
		printk(KERN_ERR NAME ": device not enabled\n");
		return -ENODEV;
		}
		device_select(SIO_GPIO_UNIT);
		if (!superio_inb(SIO_UNIT_ACT)) {
		printk(KERN_ERR NAME ": GPIO unit not enabled\n");
		return -ENODEV;
		}

		/* read GPIO unit base address */
		pc8736x_gpio_base = (superio_inb(SIO_BASE_HADDR) << 8
		\| superio_inb(SIO_BASE_LADDR));

		if (request_region(pc8736x_gpio_base, 16, NAME))
		printk(KERN_INFO NAME ": GPIO ioport %x reserved\n",
		pc8736x_gpio_base);

		r = register_chrdev(major, NAME, &pc8736x_gpio_fops);
		if (r < 0) {
		printk(KERN_ERR NAME ": unable to register character device\n");
		return r;
		}
		if (!major) {
		major = r;
		printk(KERN_DEBUG NAME ": got dynamic major %d\n", major);
		}

		pc8736x_init_shadow();
		return 0;
		}

		static void __exit pc8736x_gpio_cleanup(void)
		{
		printk(KERN_DEBUG NAME " cleanup\n");

		release_region(pc8736x_gpio_base, 16);

		unregister_chrdev(major, NAME);
		}

		module_init(pc8736x_gpio_init);
		module_exit(pc8736x_gpio_cleanup);