Commit 6cad56fd authored by Jim Cromie's avatar Jim Cromie Committed by Linus Torvalds
Browse files

[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: default avatarJim Cromie <jim.cromie@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent f31000e5

drivers/char/pc8736x_gpio.c

+23 −4
Original line number Diff line number Diff line
@@ -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);

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