2007-10-15 05:08:46

by Jim Cromie

[permalink] [raw]
Subject: [ patch .24-rc0 4/5 ] SuperIO locks coordinator - use in drivers/char/pc8736x-gpio

04 - use superio-locks in drivers/char/pc8736x_gpio

this driver keeps the slot for the lifetime of the driver
( __init til __exit ), since the driver needs the sio-port
to change pin configurations.

patches 03,04 were tested on a soekris 4801 a year ago,
the box is currently busy. Together they sanity-test
the sharing of a reservation with 2 different life-cycles.


Signed-off-by: Jim Cromie <[email protected]>
---
hwmon-superio-pc8736x-gpio
Kconfig | 1
pc8736x_gpio.c | 83 ++++++++++++++++++++++-----------------------------------
2 files changed, 34 insertions(+), 50 deletions(-)

diff -ruNp -X dontdiff -X exclude-diffs hwmon-fan-push-offset/drivers/char/Kconfig hwmon-superio.old/drivers/char/Kconfig
--- hwmon-fan-push-offset/drivers/char/Kconfig 2007-10-14 13:00:24.000000000 -0600
+++ hwmon-superio.old/drivers/char/Kconfig 2007-10-14 17:22:23.000000000 -0600
@@ -943,6 +943,7 @@ config PC8736x_GPIO
depends on X86
default SCx200_GPIO # mostly N
select NSC_GPIO # needed for support routines
+ select SUPERIO_LOCKS
help
Give userspace access to the GPIO pins on the National
Semiconductor PC-8736x (x=[03456]) SuperIO chip. The chip
diff -ruNp -X dontdiff -X exclude-diffs hwmon-fan-push-offset/drivers/char/pc8736x_gpio.c hwmon-superio.old/drivers/char/pc8736x_gpio.c
--- hwmon-fan-push-offset/drivers/char/pc8736x_gpio.c 2007-10-14 13:00:24.000000000 -0600
+++ hwmon-superio.old/drivers/char/pc8736x_gpio.c 2007-10-14 17:22:23.000000000 -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"
@@ -36,13 +37,12 @@ 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 */
+static struct superio* gate;

-#define SIO_SID 0x20 /* SuperI/O ID Register */
-#define SIO_SID_VALUE 0xe9 /* Expected value in SuperI/O ID Register */
-
-#define SIO_CF1 0x21 /* chip config, bit0 is chip enable */
+static __devinit struct superio_search where = {
+ .cmdreg_addrs = { 0x2E, 0x4E },
+ .device_ids = { 0xE1, 0xE8, 0xE4, 0xE5, 0xE9, 0 },
+};

#define PC8736X_GPIO_RANGE 16 /* ioaddr range */
#define PC8736X_GPIO_CT 32 /* minors matching 4 8 bit ports */
@@ -52,6 +52,7 @@ static u8 pc8736x_gpio_shadow[4];
#define SIO_GPIO_UNIT 0x7 /* unit number of GPIO */
#define SIO_VLM_UNIT 0x0D
#define SIO_TMS_UNIT 0x0E
+#define SIO_CF1 0x21 /* chip config, bit0 is chip enable */

/* config-space addrs to read/write each unit's runtime addr */
#define SIO_BASE_HADDR 0x60
@@ -62,7 +63,6 @@ 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 +76,9 @@ 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_select(gate, devldn);
selected_device = devldn;
}

@@ -112,7 +86,7 @@ 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 +95,19 @@ 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;
}
@@ -259,40 +233,44 @@ 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(&where);
+ 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);

@@ -319,10 +297,14 @@ 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:
@@ -341,6 +323,7 @@ static void __exit pc8736x_gpio_cleanup(

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

module_init(pc8736x_gpio_init);