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[PATCH] chardev: GPIO for SCx200 & PC-8736x: fix gpio_current, use shadow regs 

Add a working gpio_current() to pc8736x_gpio.c (the previous implementation
just threw a dev_warn), and fix gpio_change() to use gpio_current() rather
than the incorrect (and temporary) gpio_get().  Initialize shadow-regs so this
all works.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Jim Cromie 2006-06-27 02:54:24 -07:00 committed by Linus Torvalds
parent f31000e573
commit 6cad56fd88
1 changed files with 23 additions and 4 deletions
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27
drivers/char/pc8736x_gpio.c
View File

@ -33,6 +33,7 @@ MODULE_PARM_DESC(major, "Major device number");
static DEFINE_SPINLOCK(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 */
@ -184,6 +185,7 @@ static void pc8736x_gpio_set(unsigned minor, int val)
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 void pc8736x_gpio_set_high(unsigned index)
@ -196,15 +198,18 @@ static void pc8736x_gpio_set_low(unsigned index)
pc8736x_gpio_set(index, 0);
}
static int pc8736x_gpio_current(unsigned index)
static int pc8736x_gpio_current(unsigned minor)
{
dev_warn(&pdev->dev, "pc8736x_gpio_current unimplemented\n");
return 0;
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_get(index));
pc8736x_gpio_set(index, !pc8736x_gpio_current(index));
}
static struct nsc_gpio_ops pc8736x_access = {
@ -238,6 +243,18 @@ static struct file_operations pc8736x_gpio_fops = {
.read = nsc_gpio_read,
};
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 int __init pc8736x_gpio_init(void)
{
int rc = 0;
@ -317,5 +334,7 @@ static void __exit pc8736x_gpio_cleanup(void)
unregister_chrdev(major, DEVNAME);
}
EXPORT_SYMBOL(pc8736x_access);
module_init(pc8736x_gpio_init);
module_exit(pc8736x_gpio_cleanup);