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Subject[patch -mm 13/20] chardev: GPIO for SCx200 & PC-8736x: add new pc8736x_gpio module
13/20. patch.add-pc8736x-gpio

Add the brand new pc8736x_gpio driver. This is mostly based upon
scx200_gpio.c, but the platform_dev is treated separately, since its
fairly big too.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>

---

diffstat gpio-scx/patch.add-pc8736x-gpio
Makefile | 2
nsc_gpio.c | 1
pc8736x_gpio.c | 295 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 296 insertions(+), 2 deletions(-)

diff -ruNp -X dontdiff -X exclude-diffs ax-12/drivers/char/Makefile ax-13/drivers/char/Makefile
--- ax-12/drivers/char/Makefile 2006-06-17 01:27:04.000000000 -0600
+++ ax-13/drivers/char/Makefile 2006-06-17 01:39:58.000000000 -0600
@@ -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
diff -ruNp -X dontdiff -X exclude-diffs ax-12/drivers/char/nsc_gpio.c ax-13/drivers/char/nsc_gpio.c
--- ax-12/drivers/char/nsc_gpio.c 2006-06-17 01:36:56.000000000 -0600
+++ ax-13/drivers/char/nsc_gpio.c 2006-06-17 01:39:58.000000000 -0600
@@ -77,7 +77,6 @@ ssize_t nsc_gpio_write(struct file *file
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);
diff -ruNp -X dontdiff -X exclude-diffs ax-12/drivers/char/pc8736x_gpio.c ax-13/drivers/char/pc8736x_gpio.c
--- ax-12/drivers/char/pc8736x_gpio.c 1969-12-31 17:00:00.000000000 -0700
+++ ax-13/drivers/char/pc8736x_gpio.c 2006-06-17 01:39:58.000000000 -0600
@@ -0,0 +1,295 @@
+/* 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 = 0; /* 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);
+ }
+
+ 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);

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