Re: [RFC-patch 3/3] SuperIO locks coordinator - use in pc8736x_gpio

From: Jim Cromie
Date: Thu Sep 14 2006 - 03:20:19 EST




3/3 adapts drivers/char/pc8736x_gpio
this module needs the superio-port at runtime to alter pin-configs,
so it doesnt release its superio-port reservation until module-exit


diff -ruNp -X dontdiff -X exclude-diffs 6locks-3/drivers/char/pc8736x_gpio.c 6locks-4/drivers/char/pc8736x_gpio.c
--- 6locks-3/drivers/char/pc8736x_gpio.c 2006-09-07 16:11:44.000000000 -0600
+++ 6locks-4/drivers/char/pc8736x_gpio.c 2006-09-13 23:03:38.000000000 -0600
@@ -20,6 +20,7 @@
#include <linux/mutex.h>
#include <linux/nsc_gpio.h>
#include <linux/platform_device.h>
+#include <linux/superio-locks.h>
#include <asm/uaccess.h>

#define DEVNAME "pc8736x_gpio"
@@ -36,12 +37,11 @@ static DEFINE_MUTEX(pc8736x_gpio_config_
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 */
-
-#define SIO_SID 0x20 /* SuperI/O ID Register */
-#define SIO_SID_VALUE 0xe9 /* Expected value in SuperI/O ID Register */
+static u16 cmd_addrs[] = { 0x2E, 0x4E, 0 };
+static u8 devid_vals[] = { 0xE1, 0xE8, 0xE4, 0xE5, 0xE9, 0 };
+static struct superio* gate;

+#define SIO_DEVID 0x20 /* SuperI/O Device ID Register */
#define SIO_CF1 0x21 /* chip config, bit0 is chip enable */

#define PC8736X_GPIO_RANGE 16 /* ioaddr range */
@@ -62,7 +62,6 @@ static u8 pc8736x_gpio_shadow[4];
#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 */
@@ -76,35 +75,9 @@ static int port_offset[] = { 0, 4, 8, 10

static struct platform_device *pdev; /* use in dev_*() */

-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);
+ superio_outb(gate, SIO_UNIT_SEL, devldn);
selected_device = devldn;
}

@@ -112,7 +85,7 @@ 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,
+ superio_outb(gate, SIO_GPIO_PIN_SELECT,
((iminor << 1) & 0xF0) | (iminor & 0x7));
}

@@ -121,19 +94,19 @@ static inline u32 pc8736x_gpio_configure
{
u32 config, new_config;

+ superio_enter(gate);
mutex_lock(&pc8736x_gpio_config_lock);

- device_select(SIO_GPIO_UNIT);
+ /* read pin's current config value */
select_pin(index);
-
- /* read current config value */
- config = superio_inb(func_slct);
+ config = superio_inb(gate, func_slct);

/* set new config */
new_config = (config & mask) | bits;
- superio_outb(func_slct, new_config);
+ superio_outb(gate, func_slct, new_config);

mutex_unlock(&pc8736x_gpio_config_lock);
+ superio_exit(gate);

return config;
}
@@ -188,6 +161,8 @@ static void pc8736x_gpio_set(unsigned mi
pc8736x_gpio_shadow[port] = val;
}

+#if 0
+/* may re-enable for sysfs-gpio */
static void pc8736x_gpio_set_high(unsigned index)
{
pc8736x_gpio_set(index, 1);
@@ -197,6 +172,7 @@ static void pc8736x_gpio_set_low(unsigne
{
pc8736x_gpio_set(index, 0);
}
+#endif

static int pc8736x_gpio_current(unsigned minor)
{
@@ -269,40 +245,44 @@ static int __init pc8736x_gpio_init(void
rc = -ENODEV;
goto undo_platform_dev_alloc;
}
+ pc8736x_gpio_ops.dev = &pdev->dev;
+
dev_info(&pdev->dev, "NatSemi pc8736x GPIO Driver Initializing\n");

- if (!pc8736x_superio_present()) {
+ gate = superio_find(cmd_addrs, SIO_DEVID, devid_vals);
+ if (!gate) {
rc = -ENODEV;
- dev_err(&pdev->dev, "no device found\n");
+ dev_err(&pdev->dev, "no superio port found\n");
+ // goto err2;
goto undo_platform_dev_add;
}
- pc8736x_gpio_ops.dev = &pdev->dev;

/* 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);
+ superio_enter(gate);
+ rc = superio_inb(gate, SIO_CF1);
if (!(rc & 0x01)) {
rc = -ENODEV;
dev_err(&pdev->dev, "device not enabled\n");
- goto undo_platform_dev_add;
+ goto undo_superio_enter;
}
device_select(SIO_GPIO_UNIT);
- if (!superio_inb(SIO_UNIT_ACT)) {
+ if (!superio_inb(gate, SIO_UNIT_ACT)) {
rc = -ENODEV;
dev_err(&pdev->dev, "GPIO unit not enabled\n");
- goto undo_platform_dev_add;
+ goto undo_superio_enter;
}

/* read the GPIO unit base addr that chip responds to */
- pc8736x_gpio_base = (superio_inb(SIO_BASE_HADDR) << 8
- | superio_inb(SIO_BASE_LADDR));
+ pc8736x_gpio_base = (superio_inb(gate, SIO_BASE_HADDR) << 8
+ | superio_inb(gate, SIO_BASE_LADDR));

if (!request_region(pc8736x_gpio_base, PC8736X_GPIO_RANGE, DEVNAME)) {
rc = -ENODEV;
dev_err(&pdev->dev, "GPIO ioport %x busy\n",
pc8736x_gpio_base);
- goto undo_platform_dev_add;
+ goto undo_superio_enter;
}
dev_info(&pdev->dev, "GPIO ioport %x reserved\n", pc8736x_gpio_base);

@@ -329,10 +309,14 @@ static int __init pc8736x_gpio_init(void
cdev_init(&pc8736x_gpio_cdev, &pc8736x_gpio_fileops);
cdev_add(&pc8736x_gpio_cdev, devid, PC8736X_GPIO_CT);

+ superio_exit(gate); /* no release, we need to stay registered */
return 0;

undo_request_region:
release_region(pc8736x_gpio_base, PC8736X_GPIO_RANGE);
+undo_superio_enter:
+ superio_exit(gate);
+ superio_release(gate);
undo_platform_dev_add:
platform_device_del(pdev);
undo_platform_dev_alloc:
@@ -351,6 +335,7 @@ static void __exit pc8736x_gpio_cleanup(

platform_device_del(pdev);
platform_device_put(pdev);
+ superio_release(gate);
}

module_init(pc8736x_gpio_init);


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