gpio: introduce it8761e_gpio driver for IT8761E Super I/O chip

Signed-off-by: Denis Turischev <denis@compulab.co.il>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index c5cc7d9d88e30eb87e6d4ff1ea02db2bad7d5c22..a4cdbd51b1c66c13ea30bdf1b2833459a065aac8 100644 (file)
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -70,6 +70,12 @@ config GPIO_MAX730X
 
 comment "Memory mapped GPIO expanders:"
 
+config GPIO_IT8761E
+       tristate "IT8761E GPIO support"
+       depends on GPIOLIB
+       help
+         Say yes here to support GPIO functionality of IT8761E super I/O chip.
+
 config GPIO_PL061
        bool "PrimeCell PL061 GPIO support"
        depends on ARM_AMBA

diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index 508a1b202cdbaaa2be6141c61639a7b213ec309f..128abf8a98da811d7d1f372fdc8a78b81a60b162 100644 (file)
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -22,5 +22,6 @@ obj-$(CONFIG_GPIO_UCB1400)    += ucb1400_gpio.o
 obj-$(CONFIG_GPIO_XILINX)      += xilinx_gpio.o
 obj-$(CONFIG_GPIO_CS5535)      += cs5535-gpio.o
 obj-$(CONFIG_GPIO_BT8XX)       += bt8xxgpio.o
+obj-$(CONFIG_GPIO_IT8761E)     += it8761e_gpio.o
 obj-$(CONFIG_GPIO_VR41XX)      += vr41xx_giu.o
 obj-$(CONFIG_GPIO_WM831X)      += wm831x-gpio.o

diff --git a/drivers/gpio/it8761e_gpio.c b/drivers/gpio/it8761e_gpio.c
new file mode 100644 (file)
index 0000000..753219c
--- /dev/null
+++ b/drivers/gpio/it8761e_gpio.c
@@ -0,0 +1,231 @@
+/*
+ *  it8761_gpio.c - GPIO interface for IT8761E Super I/O chip
+ *
+ *  Author: Denis Turischev <denis@compulab.co.il>
+ *
+ *  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 SIO_CHIP_ID            0x8761
+#define CHIP_ID_HIGH_BYTE      0x20
+#define CHIP_ID_LOW_BYTE       0x21
+
+static u8 ports[2] = { 0x2e, 0x4e };
+static u8 port;
+
+static DEFINE_SPINLOCK(sio_lock);
+
+#define GPIO_NAME              "it8761-gpio"
+#define GPIO_BA_HIGH_BYTE      0x60
+#define GPIO_BA_LOW_BYTE       0x61
+#define GPIO_IOSIZE            4
+#define GPIO1X_IO              0xf0
+#define GPIO2X_IO              0xf1
+
+static u16 gpio_ba;
+
+static u8 read_reg(u8 addr, u8 port)
+{
+       outb(addr, port);
+       return inb(port + 1);
+}
+
+static void write_reg(u8 data, u8 addr, u8 port)
+{
+       outb(addr, port);
+       outb(data, port + 1);
+}
+
+static void enter_conf_mode(u8 port)
+{
+       outb(0x87, port);
+       outb(0x61, port);
+       outb(0x55, port);
+       outb((port == 0x2e) ? 0x55 : 0xaa, port);
+}
+
+static void exit_conf_mode(u8 port)
+{
+       outb(0x2, port);
+       outb(0x2, port + 1);
+}
+
+static void enter_gpio_mode(u8 port)
+{
+       write_reg(0x2, 0x7, port);
+}
+
+static int it8761e_gpio_get(struct gpio_chip *gc, unsigned gpio_num)
+{
+       u16 reg;
+       u8 bit;
+
+       bit = gpio_num % 7;
+       reg = (gpio_num >= 7) ? gpio_ba + 1 : gpio_ba;
+
+       return !!(inb(reg) & (1 << bit));
+}
+
+static int it8761e_gpio_direction_in(struct gpio_chip *gc, unsigned gpio_num)
+{
+       u8 curr_dirs;
+       u8 io_reg, bit;
+
+       bit = gpio_num % 7;
+       io_reg = (gpio_num >= 7) ? GPIO2X_IO : GPIO1X_IO;
+
+       spin_lock(&sio_lock);
+
+       enter_conf_mode(port);
+       enter_gpio_mode(port);
+
+       curr_dirs = read_reg(io_reg, port);
+
+       if (curr_dirs & (1 << bit))
+               write_reg(curr_dirs & ~(1 << bit), io_reg, port);
+
+       exit_conf_mode(port);
+
+       spin_unlock(&sio_lock);
+       return 0;
+}
+
+static void it8761e_gpio_set(struct gpio_chip *gc,
+                               unsigned gpio_num, int val)
+{
+       u8 curr_vals, bit;
+       u16 reg;
+
+       bit = gpio_num % 7;
+       reg = (gpio_num >= 7) ? gpio_ba + 1 : gpio_ba;
+
+       spin_lock(&sio_lock);
+
+       curr_vals = inb(reg);
+       if (val)
+               outb(curr_vals | (1 << bit) , reg);
+       else
+               outb(curr_vals & ~(1 << bit), reg);
+
+       spin_unlock(&sio_lock);
+}
+
+static int it8761e_gpio_direction_out(struct gpio_chip *gc,
+                                       unsigned gpio_num, int val)
+{
+       u8 curr_dirs, io_reg, bit;
+
+       bit = gpio_num % 7;
+       io_reg = (gpio_num >= 7) ? GPIO2X_IO : GPIO1X_IO;
+
+       it8761e_gpio_set(gc, gpio_num, val);
+
+       spin_lock(&sio_lock);
+
+       enter_conf_mode(port);
+       enter_gpio_mode(port);
+
+       curr_dirs = read_reg(io_reg, port);
+
+       if (!(curr_dirs & (1 << bit)))
+               write_reg(curr_dirs | (1 << bit), io_reg, port);
+
+       exit_conf_mode(port);
+
+       spin_unlock(&sio_lock);
+       return 0;
+}
+
+static struct gpio_chip it8761e_gpio_chip = {
+       .label                  = GPIO_NAME,
+       .owner                  = THIS_MODULE,
+       .get                    = it8761e_gpio_get,
+       .direction_input        = it8761e_gpio_direction_in,
+       .set                    = it8761e_gpio_set,
+       .direction_output       = it8761e_gpio_direction_out,
+};
+
+static int __init it8761e_gpio_init(void)
+{
+       int i, id, err;
+
+       /* chip and port detection */
+       for (i = 0; i < ARRAY_SIZE(ports); i++) {
+               spin_lock(&sio_lock);
+               enter_conf_mode(ports[i]);
+
+               id = (read_reg(CHIP_ID_HIGH_BYTE, ports[i]) << 8) +
+                               read_reg(CHIP_ID_LOW_BYTE, ports[i]);
+
+               exit_conf_mode(ports[i]);
+               spin_unlock(&sio_lock);
+
+               if (id == SIO_CHIP_ID) {
+                       port = ports[i];
+                       break;
+               }
+       }
+
+       if (!port)
+               return -ENODEV;
+
+       /* fetch GPIO base address */
+       enter_conf_mode(port);
+       enter_gpio_mode(port);
+       gpio_ba = (read_reg(GPIO_BA_HIGH_BYTE, port) << 8) +
+                               read_reg(GPIO_BA_LOW_BYTE, port);
+       exit_conf_mode(port);
+
+       if (!request_region(gpio_ba, GPIO_IOSIZE, GPIO_NAME))
+               return -EBUSY;
+
+       it8761e_gpio_chip.base = -1;
+       it8761e_gpio_chip.ngpio = 14;
+
+       err = gpiochip_add(&it8761e_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 it8761e_gpio_exit(void)
+{
+       if (gpio_ba) {
+               gpiochip_remove(&it8761e_gpio_chip);
+
+               release_region(gpio_ba, GPIO_IOSIZE);
+               gpio_ba = 0;
+       }
+}
+module_init(it8761e_gpio_init);
+module_exit(it8761e_gpio_exit);
+
+MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>");
+MODULE_DESCRIPTION("GPIO interface for IT8761E Super I/O chip");
+MODULE_LICENSE("GPL");