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authorJim Cromie <jim.cromie@gmail.com>2006-06-27 02:54:24 -0700
committerLinus Torvalds <torvalds@g5.osdl.org>2006-06-27 17:32:43 -0700
commit6cad56fd884b7eb85ae193c94b688fe76680fcbf (patch)
tree41f8abbc17063604501a529290c66059638fe2f7 /drivers/char/pc8736x_gpio.c
parentf31000e573da052b6b8bcc21faff520b4e2eda7a (diff)
downloadlinux-6cad56fd884b7eb85ae193c94b688fe76680fcbf.tar.bz2
[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>
Diffstat (limited to 'drivers/char/pc8736x_gpio.c')
-rw-r--r--drivers/char/pc8736x_gpio.c27
1 files changed, 23 insertions, 4 deletions
diff --git a/drivers/char/pc8736x_gpio.c b/drivers/char/pc8736x_gpio.c
index 48ff1fc8b06d..b8183d508332 100644
--- a/drivers/char/pc8736x_gpio.c
+++ b/drivers/char/pc8736x_gpio.c
@@ -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);