[deliverable/linux.git] / drivers / char / cs5535_gpio.c

/*
 * AMD CS5535/CS5536 GPIO driver.
 * Allows a user space process to play with the GPIO pins.
 *
 * Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the smems of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 */

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


#define NAME			"cs5535_gpio"

MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
MODULE_DESCRIPTION("AMD CS5535/CS5536 GPIO Pin Driver");
MODULE_LICENSE("GPL");

static int major;
module_param(major, int, 0);
MODULE_PARM_DESC(major, "Major device number");

static ulong mask;
module_param(mask, ulong, 0);
MODULE_PARM_DESC(mask, "GPIO channel mask");

#define MSR_LBAR_GPIO		0x5140000C

static u32 gpio_base;

static struct pci_device_id divil_pci[] = {
	{ PCI_DEVICE(PCI_VENDOR_ID_NS,  PCI_DEVICE_ID_NS_CS5535_ISA) },
	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA) },
	{ } /* NULL entry */
};
MODULE_DEVICE_TABLE(pci, divil_pci);

static struct cdev cs5535_gpio_cdev;

/* reserve 32 entries even though some aren't usable */
#define CS5535_GPIO_COUNT	32

/* IO block size */
#define CS5535_GPIO_SIZE	256

struct gpio_regmap {
	u32	rd_offset;
	u32	wr_offset;
	char	on;
	char	off;
};
static struct gpio_regmap rm[] =
{
	{ 0x30, 0x00, '1', '0' },	/* GPIOx_READ_BACK / GPIOx_OUT_VAL */
	{ 0x20, 0x20, 'I', 'i' },	/* GPIOx_IN_EN */
	{ 0x04, 0x04, 'O', 'o' },	/* GPIOx_OUT_EN */
	{ 0x08, 0x08, 't', 'T' },	/* GPIOx_OUT_OD_EN */
	{ 0x18, 0x18, 'P', 'p' },	/* GPIOx_OUT_PU_EN */
	{ 0x1c, 0x1c, 'D', 'd' },	/* GPIOx_OUT_PD_EN */
};


/**
 * Gets the register offset for the GPIO bank.
 * Low (0-15) starts at 0x00, high (16-31) starts at 0x80
 */
static inline u32 cs5535_lowhigh_base(int reg)
{
	return (reg & 0x10) << 3;
}

static ssize_t cs5535_gpio_write(struct file *file, const char __user *data,
				 size_t len, loff_t *ppos)
{
	u32	m = iminor(file->f_path.dentry->d_inode);
	int	i, j;
	u32	base = gpio_base + cs5535_lowhigh_base(m);
	u32	m0, m1;
	char	c;

	/**
	 * Creates the mask for atomic bit programming.
	 * The high 16 bits and the low 16 bits are used to set the mask.
	 * For example, GPIO 15 maps to 31,15: 0,1 => On; 1,0=> Off
	 */
	m1 = 1 << (m & 0x0F);
	m0 = m1 << 16;

	for (i = 0; i < len; ++i) {
		if (get_user(c, data+i))
			return -EFAULT;

		for (j = 0; j < ARRAY_SIZE(rm); j++) {
			if (c == rm[j].on) {
				outl(m1, base + rm[j].wr_offset);
				break;
			} else if (c == rm[j].off) {
				outl(m0, base + rm[j].wr_offset);
				break;
			}
		}
	}
	*ppos = 0;
	return len;
}

static ssize_t cs5535_gpio_read(struct file *file, char __user *buf,
				size_t len, loff_t *ppos)
{
	u32	m = iminor(file->f_path.dentry->d_inode);
	u32	base = gpio_base + cs5535_lowhigh_base(m);
	int	rd_bit = 1 << (m & 0x0f);
	int	i;
	char	ch;
	ssize_t	count = 0;

	if (*ppos >= ARRAY_SIZE(rm))
		return 0;

	for (i = *ppos; (i < (*ppos + len)) && (i < ARRAY_SIZE(rm)); i++) {
		ch = (inl(base + rm[i].rd_offset) & rd_bit) ?
		     rm[i].on : rm[i].off;

		if (put_user(ch, buf+count))
			return -EFAULT;

		count++;
	}

	/* add a line-feed if there is room */
	if ((i == ARRAY_SIZE(rm)) && (count < len)) {
		put_user('\n', buf + count);
		count++;
	}

	*ppos += count;
	return count;
}

static int cs5535_gpio_open(struct inode *inode, struct file *file)
{
	u32 m = iminor(inode);

	/* the mask says which pins are usable by this driver */
	if ((mask & (1 << m)) == 0)
		return -EINVAL;

	return nonseekable_open(inode, file);
}

static const struct file_operations cs5535_gpio_fops = {
	.owner	= THIS_MODULE,
	.write	= cs5535_gpio_write,
	.read	= cs5535_gpio_read,
	.open	= cs5535_gpio_open
};

static int __init cs5535_gpio_init(void)
{
	dev_t	dev_id;
	u32	low, hi;
	int	retval;

	if (pci_dev_present(divil_pci) == 0) {
		printk(KERN_WARNING NAME ": DIVIL not found\n");
		return -ENODEV;
	}

	/* Grab the GPIO I/O range */
	rdmsr(MSR_LBAR_GPIO, low, hi);

	/* Check the mask and whether GPIO is enabled (sanity check) */
	if (hi != 0x0000f001) {
		printk(KERN_WARNING NAME ": GPIO not enabled\n");
		return -ENODEV;
	}

	/* Mask off the IO base address */
	gpio_base = low & 0x0000ff00;

	/**
	 * Some GPIO pins
	 *  31-29,23 : reserved (always mask out)
	 *  28       : Power Button
	 *  26       : PME#
	 *  22-16    : LPC
	 *  14,15    : SMBus
	 *  9,8      : UART1
	 *  7        : PCI INTB
	 *  3,4      : UART2/DDC
	 *  2        : IDE_IRQ0
	 *  0        : PCI INTA
	 *
	 * If a mask was not specified, be conservative and only allow:
	 *  1,2,5,6,10-13,24,25,27
	 */
	if (mask != 0)
		mask &= 0x1f7fffff;
	else
		mask = 0x0b003c66;

	if (request_region(gpio_base, CS5535_GPIO_SIZE, NAME) == 0) {
		printk(KERN_ERR NAME ": can't allocate I/O for GPIO\n");
		return -ENODEV;
	}

	if (major) {
		dev_id = MKDEV(major, 0);
		retval = register_chrdev_region(dev_id, CS5535_GPIO_COUNT,
						NAME);
	} else {
		retval = alloc_chrdev_region(&dev_id, 0, CS5535_GPIO_COUNT,
					     NAME);
		major = MAJOR(dev_id);
	}

	if (retval) {
		release_region(gpio_base, CS5535_GPIO_SIZE);
		return -1;
	}

	printk(KERN_DEBUG NAME ": base=%#x mask=%#lx major=%d\n",
	       gpio_base, mask, major);

	cdev_init(&cs5535_gpio_cdev, &cs5535_gpio_fops);
	cdev_add(&cs5535_gpio_cdev, dev_id, CS5535_GPIO_COUNT);

	return 0;
}

static void __exit cs5535_gpio_cleanup(void)
{
	dev_t dev_id = MKDEV(major, 0);

	cdev_del(&cs5535_gpio_cdev);
	unregister_chrdev_region(dev_id, CS5535_GPIO_COUNT);
	release_region(gpio_base, CS5535_GPIO_SIZE);
}

module_init(cs5535_gpio_init);
module_exit(cs5535_gpio_cleanup);
Commit	Line	Data
e329113c BG	1	/*
	2	* AMD CS5535/CS5536 GPIO driver.
	3	* Allows a user space process to play with the GPIO pins.
	4	*
	5	* Copyright (c) 2005 Ben Gardner <bgardner@wabtec.com>
	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the smems of the GNU General Public License as published by
	9	* the Free Software Foundation; version 2 of the License.
	10	*/
	11
	12	#include <linux/fs.h>
	13	#include <linux/module.h>
	14	#include <linux/errno.h>
	15	#include <linux/kernel.h>
	16	#include <linux/init.h>
	17	#include <linux/cdev.h>
	18	#include <linux/ioport.h>
	19	#include <linux/pci.h>
	20	#include <asm/uaccess.h>
	21	#include <asm/io.h>
	22
	23
	24	#define NAME "cs5535_gpio"
	25
	26	MODULE_AUTHOR("Ben Gardner <bgardner@wabtec.com>");
	27	MODULE_DESCRIPTION("AMD CS5535/CS5536 GPIO Pin Driver");
	28	MODULE_LICENSE("GPL");
	29
	30	static int major;
	31	module_param(major, int, 0);
	32	MODULE_PARM_DESC(major, "Major device number");
	33
	34	static ulong mask;
	35	module_param(mask, ulong, 0);
	36	MODULE_PARM_DESC(mask, "GPIO channel mask");
	37
	38	#define MSR_LBAR_GPIO 0x5140000C
	39
	40	static u32 gpio_base;
	41
	42	static struct pci_device_id divil_pci[] = {
	43	{ PCI_DEVICE(PCI_VENDOR_ID_NS, PCI_DEVICE_ID_NS_CS5535_ISA) },
	44	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_CS5536_ISA) },
	45	{ } /* NULL entry */
	46	};
524e6752	47	MODULE_DEVICE_TABLE(pci, divil_pci);
e329113c BG	48
	49	static struct cdev cs5535_gpio_cdev;
	50
	51	/* reserve 32 entries even though some aren't usable */
	52	#define CS5535_GPIO_COUNT 32
	53
	54	/* IO block size */
	55	#define CS5535_GPIO_SIZE 256
	56
	57	struct gpio_regmap {
	58	u32 rd_offset;
	59	u32 wr_offset;
	60	char on;
	61	char off;
	62	};
	63	static struct gpio_regmap rm[] =
	64	{
	65	{ 0x30, 0x00, '1', '0' }, /* GPIOx_READ_BACK / GPIOx_OUT_VAL */
	66	{ 0x20, 0x20, 'I', 'i' }, /* GPIOx_IN_EN */
	67	{ 0x04, 0x04, 'O', 'o' }, /* GPIOx_OUT_EN */
	68	{ 0x08, 0x08, 't', 'T' }, /* GPIOx_OUT_OD_EN */
	69	{ 0x18, 0x18, 'P', 'p' }, /* GPIOx_OUT_PU_EN */
	70	{ 0x1c, 0x1c, 'D', 'd' }, /* GPIOx_OUT_PD_EN */
	71	};
	72
	73
	74	/**
	75	* Gets the register offset for the GPIO bank.
	76	* Low (0-15) starts at 0x00, high (16-31) starts at 0x80
	77	*/
	78	static inline u32 cs5535_lowhigh_base(int reg)
	79	{
	80	return (reg & 0x10) << 3;
	81	}
	82
	83	static ssize_t cs5535_gpio_write(struct file file, const char __user data,
	84	size_t len, loff_t *ppos)
	85	{
a7113a96	86	u32 m = iminor(file->f_path.dentry->d_inode);
e329113c BG	87	int i, j;
	88	u32 base = gpio_base + cs5535_lowhigh_base(m);
	89	u32 m0, m1;
	90	char c;
	91
	92	/**
	93	* Creates the mask for atomic bit programming.
	94	* The high 16 bits and the low 16 bits are used to set the mask.
	95	* For example, GPIO 15 maps to 31,15: 0,1 => On; 1,0=> Off
	96	*/
	97	m1 = 1 << (m & 0x0F);
	98	m0 = m1 << 16;
	99
	100	for (i = 0; i < len; ++i) {
	101	if (get_user(c, data+i))
	102	return -EFAULT;
	103
	104	for (j = 0; j < ARRAY_SIZE(rm); j++) {
	105	if (c == rm[j].on) {
	106	outl(m1, base + rm[j].wr_offset);
	107	break;
	108	} else if (c == rm[j].off) {
	109	outl(m0, base + rm[j].wr_offset);
	110	break;
	111	}
	112	}
	113	}
	114	*ppos = 0;
	115	return len;
	116	}
	117
	118	static ssize_t cs5535_gpio_read(struct file file, char __user buf,
	119	size_t len, loff_t *ppos)
	120	{
a7113a96	121	u32 m = iminor(file->f_path.dentry->d_inode);
e329113c BG	122	u32 base = gpio_base + cs5535_lowhigh_base(m);
	123	int rd_bit = 1 << (m & 0x0f);
	124	int i;
	125	char ch;
	126	ssize_t count = 0;
	127
	128	if (*ppos >= ARRAY_SIZE(rm))
	129	return 0;
	130
	131	for (i = ppos; (i < (ppos + len)) && (i < ARRAY_SIZE(rm)); i++) {
	132	ch = (inl(base + rm[i].rd_offset) & rd_bit) ?
	133	rm[i].on : rm[i].off;
	134
	135	if (put_user(ch, buf+count))
	136	return -EFAULT;
	137
	138	count++;
	139	}
	140
	141	/* add a line-feed if there is room */
	142	if ((i == ARRAY_SIZE(rm)) && (count < len)) {
	143	put_user('\n', buf + count);
	144	count++;
	145	}
	146
	147	*ppos += count;
	148	return count;
	149	}
	150
	151	static int cs5535_gpio_open(struct inode inode, struct file file)
	152	{
	153	u32 m = iminor(inode);
	154
	155	/* the mask says which pins are usable by this driver */
	156	if ((mask & (1 << m)) == 0)
	157	return -EINVAL;
	158
	159	return nonseekable_open(inode, file);
	160	}
	161
62322d25	162	static const struct file_operations cs5535_gpio_fops = {
e329113c BG	163	.owner = THIS_MODULE,
	164	.write = cs5535_gpio_write,
	165	.read = cs5535_gpio_read,
	166	.open = cs5535_gpio_open
	167	};
	168
	169	static int __init cs5535_gpio_init(void)
	170	{
	171	dev_t dev_id;
	172	u32 low, hi;
	173	int retval;
	174
	175	if (pci_dev_present(divil_pci) == 0) {
	176	printk(KERN_WARNING NAME ": DIVIL not found\n");
	177	return -ENODEV;
	178	}
	179
	180	/* Grab the GPIO I/O range */
	181	rdmsr(MSR_LBAR_GPIO, low, hi);
	182
	183	/* Check the mask and whether GPIO is enabled (sanity check) */
	184	if (hi != 0x0000f001) {
	185	printk(KERN_WARNING NAME ": GPIO not enabled\n");
	186	return -ENODEV;
	187	}
	188
	189	/* Mask off the IO base address */
	190	gpio_base = low & 0x0000ff00;
	191
	192	/**
	193	* Some GPIO pins
	194	* 31-29,23 : reserved (always mask out)
	195	* 28 : Power Button
	196	* 26 : PME#
	197	* 22-16 : LPC
	198	* 14,15 : SMBus
	199	* 9,8 : UART1
	200	* 7 : PCI INTB
	201	* 3,4 : UART2/DDC
	202	* 2 : IDE_IRQ0
	203	* 0 : PCI INTA
	204	*
	205	* If a mask was not specified, be conservative and only allow:
	206	* 1,2,5,6,10-13,24,25,27
	207	*/
	208	if (mask != 0)
	209	mask &= 0x1f7fffff;
	210	else
	211	mask = 0x0b003c66;
	212
	213	if (request_region(gpio_base, CS5535_GPIO_SIZE, NAME) == 0) {
	214	printk(KERN_ERR NAME ": can't allocate I/O for GPIO\n");
	215	return -ENODEV;
	216	}
	217
	218	if (major) {
	219	dev_id = MKDEV(major, 0);
	220	retval = register_chrdev_region(dev_id, CS5535_GPIO_COUNT,
	221	NAME);
	222	} else {
	223	retval = alloc_chrdev_region(&dev_id, 0, CS5535_GPIO_COUNT,
	224	NAME);
	225	major = MAJOR(dev_id);
	226	}
227
228	if (retval) {
229	release_region(gpio_base, CS5535_GPIO_SIZE);
230	return -1;
231	}
232
233	printk(KERN_DEBUG NAME ": base=%#x mask=%#lx major=%d\n",
234	gpio_base, mask, major);
235
236	cdev_init(&cs5535_gpio_cdev, &cs5535_gpio_fops);
237	cdev_add(&cs5535_gpio_cdev, dev_id, CS5535_GPIO_COUNT);
238
239	return 0;
240	}
241
242	static void __exit cs5535_gpio_cleanup(void)
243	{
244	dev_t dev_id = MKDEV(major, 0);
03246800 TS	245
03246800 TS	246	cdev_del(&cs5535_gpio_cdev);
e329113c	247	unregister_chrdev_region(dev_id, CS5535_GPIO_COUNT);
03246800	248	release_region(gpio_base, CS5535_GPIO_SIZE);
e329113c BG	249	}
	250
	251	module_init(cs5535_gpio_init);
	252	module_exit(cs5535_gpio_cleanup);