1 files changed, 353 insertions, 0 deletions
diff --git a/drivers/char/pc8736x_gpio.c b/drivers/char/pc8736x_gpio.c
new file mode 100644
index 000000000..c39a836eb
--- /dev/null
+++ b/drivers/char/pc8736x_gpio.c
@@ -0,0 +1,353 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* linux/drivers/char/pc8736x_gpio.c
+
+   National Semiconductor PC8736x GPIO driver.  Allows a user space
+   process to play with the GPIO pins.
+
+   Copyright (c) 2005,2006 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/fs.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/cdev.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/mutex.h>
+#include <linux/nsc_gpio.h>
+#include <linux/platform_device.h>
+#include <linux/uaccess.h>
+
+#define DEVNAME "pc8736x_gpio"
+
+MODULE_AUTHOR("Jim Cromie <jim.cromie@gmail.com>");
+MODULE_DESCRIPTION("NatSemi/Winbond PC-8736x 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_MUTEX(pc8736x_gpio_config_lock);
+static unsigned pc8736x_gpio_base;
+static u8 pc8736x_gpio_shadow[4];
+
+#define SIO_BASE1       0x2E	/* 1st command-reg to check */
+#define SIO_BASE2       0x4E	/* alt command-reg to check */
+
+#define SIO_SID		0x20	/* SuperI/O ID Register */
+#define SIO_SID_PC87365	0xe5	/* Expected value in ID Register for PC87365 */
+#define SIO_SID_PC87366	0xe9	/* Expected value in ID Register for PC87366 */
+
+#define SIO_CF1		0x21	/* chip config, bit0 is chip enable */
+
+#define PC8736X_GPIO_RANGE	16 /* ioaddr range */
+#define PC8736X_GPIO_CT		32 /* minors matching 4 8 bit ports */
+
+#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 struct platform_device *pdev;  /* use in dev_*() */
+
+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)
+{
+	int id;
+
+	/* try the 2 possible values, read a hardware reg to verify */
+	superio_cmd = SIO_BASE1;
+	id = superio_inb(SIO_SID);
+	if (id == SIO_SID_PC87365 || id == SIO_SID_PC87366)
+		return superio_cmd;
+
+	superio_cmd = SIO_BASE2;
+	id = superio_inb(SIO_SID);
+	if (id == SIO_SID_PC87365 || id == SIO_SID_PC87366)
+		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;
+
+	mutex_lock(&pc8736x_gpio_config_lock);
+
+	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);
+
+	mutex_unlock(&pc8736x_gpio_config_lock);
+
+	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;
+
+	dev_dbg(&pdev->dev, "_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);
+
+	dev_dbg(&pdev->dev, "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);
+
+	dev_dbg(&pdev->dev, "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);
+
+	dev_dbg(&pdev->dev, "wrote %x, read: %x\n", curval, val);
+	pc8736x_gpio_shadow[port] = val;
+}
+
+static int pc8736x_gpio_current(unsigned minor)
+{
+	int port, bit;
+	minor &= 0x1f;
+	port = minor >> 3;
+	bit = minor & 7;
+	return ((pc8736x_gpio_shadow[port] >> bit) & 0x01);
+}
+
+static void pc8736x_gpio_change(unsigned index)
+{
+	pc8736x_gpio_set(index, !pc8736x_gpio_current(index));
+}
+
+static struct nsc_gpio_ops pc8736x_gpio_ops = {
+	.owner		= THIS_MODULE,
+	.gpio_config	= pc8736x_gpio_configure,
+	.gpio_dump	= nsc_gpio_dump,
+	.gpio_get	= pc8736x_gpio_get,
+	.gpio_set	= pc8736x_gpio_set,
+	.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_gpio_ops;
+
+	dev_dbg(&pdev->dev, "open %d\n", m);
+
+	if (m >= PC8736X_GPIO_CT)
+		return -EINVAL;
+	return nonseekable_open(inode, file);
+}
+
+static const struct file_operations pc8736x_gpio_fileops = {
+	.owner	= THIS_MODULE,
+	.open	= pc8736x_gpio_open,
+	.write	= nsc_gpio_write,
+	.read	= nsc_gpio_read,
+	.llseek = no_llseek,
+};
+
+static void __init pc8736x_init_shadow(void)
+{
+	int port;
+
+	/* read the current values driven on the GPIO signals */
+	for (port = 0; port < 4; ++port)
+		pc8736x_gpio_shadow[port]
+		    = inb_p(pc8736x_gpio_base + port_offset[port]
+			    + PORT_OUT);
+
+}
+
+static struct cdev pc8736x_gpio_cdev;
+
+static int __init pc8736x_gpio_init(void)
+{
+	int rc;
+	dev_t devid;
+
+	pdev = platform_device_alloc(DEVNAME, 0);
+	if (!pdev)
+		return -ENOMEM;
+
+	rc = platform_device_add(pdev);
+	if (rc) {
+		rc = -ENODEV;
+		goto undo_platform_dev_alloc;
+	}
+	dev_info(&pdev->dev, "NatSemi pc8736x GPIO Driver Initializing\n");
+
+	if (!pc8736x_superio_present()) {
+		rc = -ENODEV;
+		dev_err(&pdev->dev, "no device found\n");
+		goto undo_platform_dev_add;
+	}
+	pc8736x_gpio_ops.dev = &pdev->dev;
+
+	/* 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)) {
+		rc = -ENODEV;
+		dev_err(&pdev->dev, "device not enabled\n");
+		goto undo_platform_dev_add;
+	}
+	device_select(SIO_GPIO_UNIT);
+	if (!superio_inb(SIO_UNIT_ACT)) {
+		rc = -ENODEV;
+		dev_err(&pdev->dev, "GPIO unit not enabled\n");
+		goto undo_platform_dev_add;
+	}
+
+	/* read the GPIO unit base addr that chip responds to */
+	pc8736x_gpio_base = (superio_inb(SIO_BASE_HADDR) << 8
+			     | superio_inb(SIO_BASE_LADDR));
+
+	if (!request_region(pc8736x_gpio_base, PC8736X_GPIO_RANGE, DEVNAME)) {
+		rc = -ENODEV;
+		dev_err(&pdev->dev, "GPIO ioport %x busy\n",
+			pc8736x_gpio_base);
+		goto undo_platform_dev_add;
+	}
+	dev_info(&pdev->dev, "GPIO ioport %x reserved\n", pc8736x_gpio_base);
+
+	if (major) {
+		devid = MKDEV(major, 0);
+		rc = register_chrdev_region(devid, PC8736X_GPIO_CT, DEVNAME);
+	} else {
+		rc = alloc_chrdev_region(&devid, 0, PC8736X_GPIO_CT, DEVNAME);
+		major = MAJOR(devid);
+	}
+
+	if (rc < 0) {
+		dev_err(&pdev->dev, "register-chrdev failed: %d\n", rc);
+		goto undo_request_region;
+	}
+	if (!major) {
+		major = rc;
+		dev_dbg(&pdev->dev, "got dynamic major %d\n", major);
+	}
+
+	pc8736x_init_shadow();
+
+	/* ignore minor errs, and succeed */
+	cdev_init(&pc8736x_gpio_cdev, &pc8736x_gpio_fileops);
+	cdev_add(&pc8736x_gpio_cdev, devid, PC8736X_GPIO_CT);
+
+	return 0;
+
+undo_request_region:
+	release_region(pc8736x_gpio_base, PC8736X_GPIO_RANGE);
+undo_platform_dev_add:
+	platform_device_del(pdev);
+undo_platform_dev_alloc:
+	platform_device_put(pdev);
+
+	return rc;
+}
+
+static void __exit pc8736x_gpio_cleanup(void)
+{
+	dev_dbg(&pdev->dev, "cleanup\n");
+
+	cdev_del(&pc8736x_gpio_cdev);
+	unregister_chrdev_region(MKDEV(major,0), PC8736X_GPIO_CT);
+	release_region(pc8736x_gpio_base, PC8736X_GPIO_RANGE);
+
+	platform_device_unregister(pdev);
+}
+
+module_init(pc8736x_gpio_init);
+module_exit(pc8736x_gpio_cleanup);