[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>
diff --git a/drivers/char/pc8736x_gpio.c b/drivers/char/pc8736x_gpio.c
index 48ff1fc..b8183d5 100644
--- a/drivers/char/pc8736x_gpio.c
+++ b/drivers/char/pc8736x_gpio.c
@@ -33,6 +33,7 @@
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 @@
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 @@
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 @@
.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 @@
unregister_chrdev(major, DEVNAME);
}
+EXPORT_SYMBOL(pc8736x_access);
+
module_init(pc8736x_gpio_init);
module_exit(pc8736x_gpio_cleanup);