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gpio: Add support for PC8741x SuperIO chip GPIOs

PATCH In review Jonathan McDowell 2 participants 3 messages Apr 20, 2011 – Jun 15, 2011 GPIO

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#0 lore raw

PATCH 1/1 gpio: Add support for PC8741x SuperIO chip GPIOs

Add support for the GPIOs on the National Semiconductor/Winbond PC87413/87414/87416/87417 SuperIO LPC family.

These chips feature 51 GPIOs (46 configurable as input or output, 5 output only).

drivers/gpio/Kconfig +11 -0
index 664660e..cc150db 100644
@@ -81,6 +81,17 @@ config GPIO_IT8761E
 	help
 	  Say yes here to support GPIO functionality of IT8761E super I/O chip.
 
+config GPIO_PC8741X
+	tristate "PC8741x SuperIO GPIO support"
+	depends on GPIOLIB
+	help
+	  Say yes here to support the GPIO functionality of the
+	  PC87413/87414/87416/87417 SuperIO chips. These chips contain a
+	  total of 51 GPIOs.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called pc8741x_gpio.
+
 config GPIO_PL061
 	bool "PrimeCell PL061 GPIO support"
 	depends on ARM_AMBA
drivers/gpio/Makefile +1 -0
index 3351cf8..d2752b2 100644
@@ -19,6 +19,7 @@ obj-$(CONFIG_GPIO_MAX732X)	+= max732x.o
 obj-$(CONFIG_GPIO_MC33880)	+= mc33880.o
 obj-$(CONFIG_GPIO_MCP23S08)	+= mcp23s08.o
 obj-$(CONFIG_GPIO_74X164)	+= 74x164.o
+obj-$(CONFIG_GPIO_PC8741X)	+= pc8741x_gpio.o
 obj-$(CONFIG_GPIO_PCA953X)	+= pca953x.o
 obj-$(CONFIG_GPIO_PCF857X)	+= pcf857x.o
 obj-$(CONFIG_GPIO_PCH)		+= pch_gpio.o
drivers/gpio/pc8741x_gpio.c new file +271 -0

271 lines not on this page · raw message

#1 lore raw

I never saw any reply to the below. Was there some problem with it, or did it just get forgotten about?

(Also the VSC055 GPIO driver that Jonathan Cameron commented on seemed to disappear into the ether too. Were more changes to it necessary?)

Quoted 309 lines · Jonathan McDowell

Add support for the GPIOs on the National Semiconductor/Winbond PC87413/87414/87416/87417 SuperIO LPC family.

These chips feature 51 GPIOs (46 configurable as input or output, 5 output only).

drivers/gpio/Kconfig +11 -0
index 664660e..cc150db 100644
@@ -81,6 +81,17 @@ config GPIO_IT8761E
 	help
 	  Say yes here to support GPIO functionality of IT8761E super I/O chip.
 
+config GPIO_PC8741X
+	tristate "PC8741x SuperIO GPIO support"
+	depends on GPIOLIB
+	help
+	  Say yes here to support the GPIO functionality of the
+	  PC87413/87414/87416/87417 SuperIO chips. These chips contain a
+	  total of 51 GPIOs.
+
+	  This driver can also be built as a module.  If so, the module
+	  will be called pc8741x_gpio.
+
 config GPIO_PL061
 	bool "PrimeCell PL061 GPIO support"
 	depends on ARM_AMBA
drivers/gpio/Makefile +1 -0
index 3351cf8..d2752b2 100644
@@ -19,6 +19,7 @@ obj-$(CONFIG_GPIO_MAX732X)	+= max732x.o
 obj-$(CONFIG_GPIO_MC33880)	+= mc33880.o
 obj-$(CONFIG_GPIO_MCP23S08)	+= mcp23s08.o
 obj-$(CONFIG_GPIO_74X164)	+= 74x164.o
+obj-$(CONFIG_GPIO_PC8741X)	+= pc8741x_gpio.o
 obj-$(CONFIG_GPIO_PCA953X)	+= pca953x.o
 obj-$(CONFIG_GPIO_PCF857X)	+= pcf857x.o
 obj-$(CONFIG_GPIO_PCH)		+= pch_gpio.o
drivers/gpio/pc8741x_gpio.c new file +261 -0
new file mode 100644
index 0000000..cea084a
@@ -0,0 +1,271 @@
+/*
+ *  pc8741x_gpio.c - GPIO interface for PC87413/4/6/7 Super I/O chip
+ *
+ *  Copyright 2011 Jonathan McDowell <[email protected]>
+ *
+ *  Based on drivers/gpio/it8761e_gpio.c
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; see the file COPYING.  If not, write to
+ *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+
+#include <linux/gpio.h>
+
+#define PC8741X_CHIP_ID		0xEE
+
+#define PC8741X_FUNC_SEL	0x07
+#define PC8741X_SID		0x20
+#define PC8741X_SRID		0x27
+#define PC8741X_FUNC_ENABLE	0x30
+#define PC8741X_BASE_HIGH	0x60
+#define PC8741X_BASE_LOW	0x61
+
+#define PC8741X_GPSEL		0xF0
+#define PC8741X_GPCFG1		0xF1
+#define PC8741X_GPEVR		0xF2
+#define PC8741X_GPCFG2		0xF3
+
+#define PC8741X_FUNC_GPIO	0x07
+
+static u8 ports[2] = { 0x2e, 0x4e };
+static u8 port;
+
+static u8 block_in_offs[6] = { 1, 3, 7, 9, 11, 15 };
+static u8 block_out_offs[7] = { 0, 2, 6, 8, 10, 14, 16 };
+
+static DEFINE_SPINLOCK(pc8741x_sio_lock);
+
+#define GPIO_NAME		"pc8741x-gpio"
+#define GPIO_IOSIZE		17
+
+static u16 gpio_ba;
+
+static int pc8741x_superio_enter(int base)
+{
+	if (!request_muxed_region(base, 2, GPIO_NAME))
+		return -EBUSY;
+
+	return 0;
+}
+
+static void pc8741x_superio_exit(int base)
+{
+	release_region(base, 2);
+}
+
+static u8 pc8741x_read_reg(u8 addr, u8 port)
+{
+	outb(addr, port);
+	return inb(port + 1);
+}
+
+static void pc8741x_write_reg(u8 data, u8 addr, u8 port)
+{
+	outb(addr, port);
+	outb(data, port + 1);
+}
+
+static void pc8741x_select_func(u8 port, u8 func)
+{
+	pc8741x_write_reg(func, PC8741X_FUNC_SEL, port);
+}
+
+static int pc8741x_gpio_get(struct gpio_chip *gc, unsigned gpio_num)
+{
+	u8 block, pin;
+
+	if (gpio_num < 46) {
+		block = gpio_num >> 3;
+		pin = gpio_num & 7;
+	} else {
+		/* Block 6 is output only */
+		return 0;
+	}
+
+	return !!(inb(gpio_ba + block_in_offs[block]) & (1 << pin));
+}
+
+static int pc8741x_gpio_direction_in(struct gpio_chip *gc, unsigned gpio_num)
+{
+	u8 block, pin, cur;
+	int err;
+
+	if (gpio_num < 46) {
+		block = gpio_num >> 3;
+		pin = gpio_num & 7;
+	} else {
+		/* Block 6 is output only */
+		return -EINVAL;
+	}
+
+	err = pc8741x_superio_enter(port);
+	if (err)
+		return err;
+
+	pc8741x_select_func(port, PC8741X_FUNC_GPIO);
+	pc8741x_write_reg(block << 4 & pin, PC8741X_GPSEL, port);
+
+	cur = pc8741x_read_reg(PC8741X_GPCFG1, port);
+
+	if (cur & 1)
+		pc8741x_write_reg(cur & ~1, PC8741X_GPCFG1, port);
+
+	pc8741x_superio_exit(port);
+	return 0;
+}
+
+static void pc8741x_gpio_set(struct gpio_chip *gc,
+				unsigned gpio_num, int val)
+{
+	u8 block, pin, cur;
+
+	if (gpio_num < 46) {
+		block = gpio_num >> 3;
+		pin = gpio_num & 7;
+	} else {
+		block = 6;
+		pin = gpio_num - 46;
+	}
+
+	spin_lock(&pc8741x_sio_lock);
+
+	cur = inb(gpio_ba + block_out_offs[block]);
+
+	if (val)
+		outb(cur | (1 << pin), gpio_ba + block_out_offs[block]);
+	else
+		outb(cur & ~(1 << pin), gpio_ba + block_out_offs[block]);
+
+	spin_unlock(&pc8741x_sio_lock);
+}
+
+static int pc8741x_gpio_direction_out(struct gpio_chip *gc, unsigned gpio_num,
+					int val)
+{
+	u8 block, pin, cur;
+	int err;
+
+	pc8741x_gpio_set(gc, gpio_num, val);
+
+	if (gpio_num < 46) {
+		block = gpio_num >> 3;
+		pin = gpio_num & 7;
+	} else {
+		block = 6;
+		pin = gpio_num - 47;
+	}
+
+	err = pc8741x_superio_enter(port);
+	if (err)
+		return err;
+
+	pc8741x_select_func(port, PC8741X_FUNC_GPIO);
+	pc8741x_write_reg(block << 4 & pin, PC8741X_GPSEL, port);
+
+	cur = pc8741x_read_reg(PC8741X_GPCFG1, port);
+
+	if (!(cur & 1))
+		pc8741x_write_reg(cur | 1, PC8741X_GPCFG1, port);
+
+	pc8741x_superio_exit(port);
+
+	return 0;
+}
+
+static struct gpio_chip pc8741x_gpio_chip = {
+	.label			= GPIO_NAME,
+	.owner			= THIS_MODULE,
+	.get			= pc8741x_gpio_get,
+	.direction_input	= pc8741x_gpio_direction_in,
+	.set			= pc8741x_gpio_set,
+	.direction_output	= pc8741x_gpio_direction_out,
+};
+
+static int __init pc8741x_gpio_init(void)
+{
+	int i, id, err;
+
+	/* chip and port detection */
+	for (i = 0; i < ARRAY_SIZE(ports); i++) {
+		if (!pc8741x_superio_enter(ports[i])) {
+
+			id = pc8741x_read_reg(PC8741X_SID, ports[i]);
+
+			pc8741x_superio_exit(ports[i]);
+
+			if (id == PC8741X_CHIP_ID) {
+				port = ports[i];
+				break;
+			}
+		}
+	}
+
+	if (!port)
+		return -ENODEV;
+
+	err = pc8741x_superio_enter(port);
+	if (err)
+		return err;
+	id = pc8741x_read_reg(PC8741X_SRID, port);
+	printk(KERN_INFO "pc8741x_gpio: Found PC8741x revision %d\n", id);
+
+	/* fetch GPIO base address */
+	pc8741x_select_func(port, PC8741X_FUNC_GPIO);
+	pc8741x_write_reg(1, PC8741X_FUNC_ENABLE, port);
+	gpio_ba = (pc8741x_read_reg(PC8741X_BASE_HIGH, port) << 8) +
+				pc8741x_read_reg(PC8741X_BASE_LOW, port);
+	pc8741x_superio_exit(port);
+
+	if (!request_region(gpio_ba, GPIO_IOSIZE, GPIO_NAME))
+		return -EBUSY;
+
+	pc8741x_gpio_chip.base = -1;
+	pc8741x_gpio_chip.ngpio = 51;
+
+	err = gpiochip_add(&pc8741x_gpio_chip);
+	if (err < 0)
+		goto gpiochip_add_err;
+
+	return 0;
+
+gpiochip_add_err:
+	release_region(gpio_ba, GPIO_IOSIZE);
+	gpio_ba = 0;
+	return err;
+}
+
+static void __exit pc8741x_gpio_exit(void)
+{
+	if (gpio_ba) {
+		int ret = gpiochip_remove(&pc8741x_gpio_chip);
+
+		WARN(ret, "%s(): gpiochip_remove() failed, ret=%d\n",
+				__func__, ret);
+

drivers/gpio/pc8741x_gpio.c line 271

Quoted 10 lines
drivers/gpio/pc8741x_gpio.c new file +10 -0
+		release_region(gpio_ba, GPIO_IOSIZE);
+		gpio_ba = 0;
+	}
+}
+module_init(pc8741x_gpio_init);
+module_exit(pc8741x_gpio_exit);
+
+MODULE_AUTHOR("Jonathan McDowell <[email protected]>");
+MODULE_DESCRIPTION("GPIO interface for PC87413/4/6/7 Super I/O chip");
+MODULE_LICENSE("GPL");

J.

Signature · 1 line
Know Thy User.
#2 lore raw
Quoted 5 lines · Jonathan McDowell

I never saw any reply to the below. Was there some problem with it, or did it just get forgotten about?

(Also the VSC055 GPIO driver that Jonathan Cameron commented on seemed to disappear into the ether too. Were more changes to it necessary?)

That sometimes happens. April also turned out to be a particularly bad month for dropping stuff on the floor for me. Comments below.

Quoted 41 lines · Jonathan McDowell
Quoted 39 lines

Add support for the GPIOs on the National Semiconductor/Winbond PC87413/87414/87416/87417 SuperIO LPC family.

These chips feature 51 GPIOs (46 configurable as input or output, 5 output only).

drivers/gpio/Kconfig +0 -0
index 664660e..cc150db 100644
@@ -81,6 +81,17 @@ config GPIO_IT8761E

      help
        Say yes here to support GPIO functionality of IT8761E super I/O chip.

drivers/gpio/Kconfig +11 -0
+config GPIO_PC8741X
+     tristate "PC8741x SuperIO GPIO support"
+     depends on GPIOLIB
+     help
+       Say yes here to support the GPIO functionality of the
+       PC87413/87414/87416/87417 SuperIO chips. These chips contain a
+       total of 51 GPIOs.
+
+       This driver can also be built as a module.  If so, the module
+       will be called pc8741x_gpio.
+

 config GPIO_PL061
      bool "PrimeCell PL061 GPIO support"
      depends on ARM_AMBA

drivers/gpio/Makefile +0 -0
index 3351cf8..d2752b2 100644
@@ -19,6 +19,7 @@ obj-$(CONFIG_GPIO_MAX732X)  += max732x.o

 obj-$(CONFIG_GPIO_MC33880)   += mc33880.o
 obj-$(CONFIG_GPIO_MCP23S08)  += mcp23s08.o
 obj-$(CONFIG_GPIO_74X164)    += 74x164.o
+obj-$(CONFIG_GPIO_PC8741X)   += pc8741x_gpio.o

Quoted 8 lines

drivers/gpio/pc8741x_gpio.c

Quoted 8 lines

 obj-$(CONFIG_GPIO_PCA953X)   += pca953x.o obj-$(CONFIG_GPIO_PCF857X)   += pcf857x.o obj-$(CONFIG_GPIO_PCH)               += pch_gpio.o

drivers/gpio/pc8741x_gpio.c new file +0 -0
new file mode 100644
index 0000000..cea084a

drivers/gpio/gpio-pc8741x.c please. I'm now enforcing naming convention on these drivers.

Quoted 3 lines

drivers/gpio/pc8741x_gpio.c line 2

Quoted 3 lines
drivers/gpio/pc8741x_gpio.c new file +2 -0
@@ -0,0 +1,271 @@
+/*
+ *  pc8741x_gpio.c - GPIO interface for PC87413/4/6/7 Super I/O chip

Nit: Drop the file name. It's the description that is the real useful bit in the header block, whereas the filename gets stale if the driver gets moved/renamed.

Quoted 4 lines

drivers/gpio/pc8741x_gpio.c line 6

Quoted 4 lines
drivers/gpio/pc8741x_gpio.c new file +4 -0
+ *
+ *  Copyright 2011 Jonathan McDowell <[email protected]>
+ *
+ *  Based on drivers/gpio/it8761e_gpio.c

Then you probably need to preserve the copyright notices from that driver too.

Quoted 131 lines
Quoted 131 lines
drivers/gpio/pc8741x_gpio.c new file +131 -0
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; see the file COPYING.  If not, write to
+ *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/io.h>
+#include <linux/errno.h>
+#include <linux/ioport.h>
+
+#include <linux/gpio.h>
+
+#define PC8741X_CHIP_ID              0xEE
+
+#define PC8741X_FUNC_SEL     0x07
+#define PC8741X_SID          0x20
+#define PC8741X_SRID         0x27
+#define PC8741X_FUNC_ENABLE  0x30
+#define PC8741X_BASE_HIGH    0x60
+#define PC8741X_BASE_LOW     0x61
+
+#define PC8741X_GPSEL                0xF0
+#define PC8741X_GPCFG1               0xF1
+#define PC8741X_GPEVR                0xF2
+#define PC8741X_GPCFG2               0xF3
+
+#define PC8741X_FUNC_GPIO    0x07
+
+static u8 ports[2] = { 0x2e, 0x4e };
+static u8 port;
+
+static u8 block_in_offs[6] = { 1, 3, 7, 9, 11, 15 };
+static u8 block_out_offs[7] = { 0, 2, 6, 8, 10, 14, 16 };
+
+static DEFINE_SPINLOCK(pc8741x_sio_lock);
+
+#define GPIO_NAME            "pc8741x-gpio"
+#define GPIO_IOSIZE          17
+
+static u16 gpio_ba;
+
+static int pc8741x_superio_enter(int base)
+{
+     if (!request_muxed_region(base, 2, GPIO_NAME))
+             return -EBUSY;
+
+     return 0;
+}
+
+static void pc8741x_superio_exit(int base)
+{
+     release_region(base, 2);
+}
+
+static u8 pc8741x_read_reg(u8 addr, u8 port)
+{
+     outb(addr, port);
+     return inb(port + 1);
+}
+
+static void pc8741x_write_reg(u8 data, u8 addr, u8 port)
+{
+     outb(addr, port);
+     outb(data, port + 1);
+}
+
+static void pc8741x_select_func(u8 port, u8 func)
+{
+     pc8741x_write_reg(func, PC8741X_FUNC_SEL, port);
+}
+
+static int pc8741x_gpio_get(struct gpio_chip *gc, unsigned gpio_num)
+{
+     u8 block, pin;
+
+     if (gpio_num < 46) {
+             block = gpio_num >> 3;
+             pin = gpio_num & 7;
+     } else {
+             /* Block 6 is output only */
+             return 0;
+     }
+
+     return !!(inb(gpio_ba + block_in_offs[block]) & (1 << pin));
+}
+
+static int pc8741x_gpio_direction_in(struct gpio_chip *gc, unsigned gpio_num)
+{
+     u8 block, pin, cur;
+     int err;
+
+     if (gpio_num < 46) {
+             block = gpio_num >> 3;
+             pin = gpio_num & 7;
+     } else {
+             /* Block 6 is output only */
+             return -EINVAL;
+     }
+
+     err = pc8741x_superio_enter(port);
+     if (err)
+             return err;
+
+     pc8741x_select_func(port, PC8741X_FUNC_GPIO);
+     pc8741x_write_reg(block << 4 & pin, PC8741X_GPSEL, port);
+
+     cur = pc8741x_read_reg(PC8741X_GPCFG1, port);
+
+     if (cur & 1)
+             pc8741x_write_reg(cur & ~1, PC8741X_GPCFG1, port);
+
+     pc8741x_superio_exit(port);
+     return 0;
+}
+
+static void pc8741x_gpio_set(struct gpio_chip *gc,
+                             unsigned gpio_num, int val)
+{
+     u8 block, pin, cur;
Quoted 8 lines

drivers/gpio/pc8741x_gpio.c line 145

Quoted 8 lines
drivers/gpio/pc8741x_gpio.c new file +8 -0
+
+     if (gpio_num < 46) {
+             block = gpio_num >> 3;
+             pin = gpio_num & 7;
+     } else {
+             block = 6;
+             pin = gpio_num - 46;
+     }

Given that there are multiple blocks on this chip, it would probably be better off to register a different gpio_chip for each block so that your driver doesn't have to got through calculations about which block is being selected. It also means that you can make your driver use the generic_gpio library for most of the accessors, which you should be doing anyway now that it is available. You'll be able to drop a lot of code from this driver by using it, and it correctly implements a shadow register for the output state which is also something that this driver should be doing.

Quoted 99 lines
Quoted 99 lines
drivers/gpio/pc8741x_gpio.c new file +99 -0
+
+     spin_lock(&pc8741x_sio_lock);
+
+     cur = inb(gpio_ba + block_out_offs[block]);
+
+     if (val)
+             outb(cur | (1 << pin), gpio_ba + block_out_offs[block]);
+     else
+             outb(cur & ~(1 << pin), gpio_ba + block_out_offs[block]);
+
+     spin_unlock(&pc8741x_sio_lock);
+}
+
+static int pc8741x_gpio_direction_out(struct gpio_chip *gc, unsigned gpio_num,
+                                     int val)
+{
+     u8 block, pin, cur;
+     int err;
+
+     pc8741x_gpio_set(gc, gpio_num, val);
+
+     if (gpio_num < 46) {
+             block = gpio_num >> 3;
+             pin = gpio_num & 7;
+     } else {
+             block = 6;
+             pin = gpio_num - 47;
+     }
+
+     err = pc8741x_superio_enter(port);
+     if (err)
+             return err;
+
+     pc8741x_select_func(port, PC8741X_FUNC_GPIO);
+     pc8741x_write_reg(block << 4 & pin, PC8741X_GPSEL, port);
+
+     cur = pc8741x_read_reg(PC8741X_GPCFG1, port);
+
+     if (!(cur & 1))
+             pc8741x_write_reg(cur | 1, PC8741X_GPCFG1, port);
+
+     pc8741x_superio_exit(port);
+
+     return 0;
+}
+
+static struct gpio_chip pc8741x_gpio_chip = {
+     .label                  = GPIO_NAME,
+     .owner                  = THIS_MODULE,
+     .get                    = pc8741x_gpio_get,
+     .direction_input        = pc8741x_gpio_direction_in,
+     .set                    = pc8741x_gpio_set,
+     .direction_output       = pc8741x_gpio_direction_out,
+};
+
+static int __init pc8741x_gpio_init(void)
+{
+     int i, id, err;
+
+     /* chip and port detection */
+     for (i = 0; i < ARRAY_SIZE(ports); i++) {
+             if (!pc8741x_superio_enter(ports[i])) {
+
+                     id = pc8741x_read_reg(PC8741X_SID, ports[i]);
+
+                     pc8741x_superio_exit(ports[i]);
+
+                     if (id == PC8741X_CHIP_ID) {
+                             port = ports[i];
+                             break;
+                     }
+             }
+     }
+
+     if (!port)
+             return -ENODEV;
+
+     err = pc8741x_superio_enter(port);
+     if (err)
+             return err;
+     id = pc8741x_read_reg(PC8741X_SRID, port);
+     printk(KERN_INFO "pc8741x_gpio: Found PC8741x revision %d\n", id);
+
+     /* fetch GPIO base address */
+     pc8741x_select_func(port, PC8741X_FUNC_GPIO);
+     pc8741x_write_reg(1, PC8741X_FUNC_ENABLE, port);
+     gpio_ba = (pc8741x_read_reg(PC8741X_BASE_HIGH, port) << 8) +
+                             pc8741x_read_reg(PC8741X_BASE_LOW, port);
+     pc8741x_superio_exit(port);
+
+     if (!request_region(gpio_ba, GPIO_IOSIZE, GPIO_NAME))
+             return -EBUSY;
+
+     pc8741x_gpio_chip.base = -1;
+     pc8741x_gpio_chip.ngpio = 51;
+
+     err = gpiochip_add(&pc8741x_gpio_chip);
+     if (err < 0)
+             goto gpiochip_add_err;
Quoted 8 lines

drivers/gpio/pc8741x_gpio.c line 252

Quoted 8 lines
drivers/gpio/pc8741x_gpio.c new file +8 -0
+
+     return 0;
+
+gpiochip_add_err:
+     release_region(gpio_ba, GPIO_IOSIZE);
+     gpio_ba = 0;
+     return err;
+}

Driver initialization should not be performed in the module_init hook.
The module init hook should only register a platform_driver, and the
drivers .probe() hook should actually instantiate the device.

Quoted 6 lines
Quoted 6 lines
drivers/gpio/pc8741x_gpio.c new file +6 -0
+
+static void __exit pc8741x_gpio_exit(void)
+{
+     if (gpio_ba) {
+             int ret = gpiochip_remove(&pc8741x_gpio_chip);
+
Quoted 8 lines

drivers/gpio/pc8741x_gpio.c line 266

Quoted 8 lines
drivers/gpio/pc8741x_gpio.c new file +8 -0
+             WARN(ret, "%s(): gpiochip_remove() failed, ret=%d\n",
+                             __func__, ret);
+
+             release_region(gpio_ba, GPIO_IOSIZE);
+             gpio_ba = 0;
+     }
+}
+module_init(pc8741x_gpio_init);

Nit: module_init() should appear immediately after the module_init() hook.

Quoted 11 lines

drivers/gpio/pc8741x_gpio.c line 271

Quoted 5 lines
drivers/gpio/pc8741x_gpio.c new file +5 -0
+module_exit(pc8741x_gpio_exit);
+
+MODULE_AUTHOR("Jonathan McDowell <[email protected]>");
+MODULE_DESCRIPTION("GPIO interface for PC87413/4/6/7 Super I/O chip");
+MODULE_LICENSE("GPL");

J.

--
Know Thy User.

Signature · 2 lines
Grant Likely, B.Sc., P.Eng.
Secret Lab Technologies Ltd.