From 681a3e7dab868a8c390724494e8b79dc596b9e0f Mon Sep 17 00:00:00 2001 From: Jim Cromie Date: Tue, 27 Jun 2006 02:54:21 -0700 Subject: [PATCH] chardev: GPIO for SCx200 & PC-8736x: add new pc8736x_gpio module 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/char/pc8736x_gpio.c | 296 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 296 insertions(+) create mode 100644 drivers/char/pc8736x_gpio.c (limited to 'drivers/char/pc8736x_gpio.c') diff --git a/drivers/char/pc8736x_gpio.c b/drivers/char/pc8736x_gpio.c new file mode 100644 index 00000000000..83f24279f54 --- /dev/null +++ b/drivers/char/pc8736x_gpio.c @@ -0,0 +1,296 @@ +/* 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 + + adapted from linux/drivers/char/scx200_gpio.c + Copyright (c) 2001,2002 Christer Weinigel , +*/ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define NAME "pc8736x_gpio" + +MODULE_AUTHOR("Jim Cromie "); +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); -- cgit v1.2.3