This patch adds support for an I2C bus using GPIO devices. It is preconfigured
to use the MTX-1 GPIO lines dedicated to I2C.
Signed-off-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxx>
--
diff -urN linux-2.6.19/drivers/i2c/busses/Kconfig linux-2.6.19.new/drivers/i2c/busses/Kconfig
--- linux-2.6.19/drivers/i2c/busses/Kconfig 2006-11-29 22:57:37.000000000 +0100
+++ linux-2.6.19.new/drivers/i2c/busses/Kconfig 2006-12-28 17:04:34.000000000 +0100
@@ -84,6 +84,17 @@
This driver can also be built as a module. If so, the module
will be called i2c-au1550.
+config I2C_AU1X00GPIO
+ tristate "Au1x00 i2c using GPIO pins"
+ depends on I2C
+ select I2C_ALGOBIT
+ help
+ If you say yest to this option, support will be included for the
+ Au1x00 GPIO interface.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-au1x00gpio.
+
config I2C_ELEKTOR
tristate "Elektor ISA card"
depends on I2C && ISA && BROKEN_ON_SMP
diff -urN linux-2.6.19/drivers/i2c/busses/Makefile linux-2.6.19.new/drivers/i2c/busses/Makefile
--- linux-2.6.19/drivers/i2c/busses/Makefile 2006-11-29 22:57:37.000000000 +0100
+++ linux-2.6.19.new/drivers/i2c/busses/Makefile 2006-12-28 03:07:37.000000000 +0100
@@ -9,6 +9,7 @@
obj-$(CONFIG_I2C_AMD756_S4882) += i2c-amd756-s4882.o
obj-$(CONFIG_I2C_AMD8111) += i2c-amd8111.o
obj-$(CONFIG_I2C_AU1550) += i2c-au1550.o
+obj-$(CONFIG_I2C_AU1X00GPIO) += i2c-au1x00gpio.o
obj-$(CONFIG_I2C_ELEKTOR) += i2c-elektor.o
obj-$(CONFIG_I2C_HYDRA) += i2c-hydra.o
obj-$(CONFIG_I2C_I801) += i2c-i801.o
diff -urN linux-2.6.19/drivers/i2c/busses/i2c-au1x00gpio.c linux-2.6.19.new/drivers/i2c/busses/i2c-au1x00gpio.c
--- linux-2.6.19/drivers/i2c/busses/i2c-au1x00gpio.c 1970-01-01 01:00:00.000000000 +0100
+++ linux-2.6.19.new/drivers/i2c/busses/i2c-au1x00gpio.c 2006-12-28 17:02:10.000000000 +0100
@@ -0,0 +1,406 @@
+/* ------------------------------------------------------------------------- */
+/* i2c-au1x00gpio.c i2c-hw access for Au1x00 GPIO pins. */
+/* ------------------------------------------------------------------------- */
+/* Copyright (C) 1995-2000 Michael Stickel
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ 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; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
+/* ------------------------------------------------------------------------- */
+
+/* With some changes from Ky�stialkki <kmalkki@xxxxxxxxx> and even
+ Frodo Looijaard <frodol@xxxxxx>
+ Simon G. Vogl
+*/
+
+/* $Id: i2c-au1x00gpio.c,v 1.1.1.2 2004/01/22 15:35:47 br1 Exp $ */
+
+#include <linux/module.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/stddef.h>
+#include <linux/ioport.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm-mips/mach-au1x00/au1000.h>
+#include <asm-mips/mach-au1x00/au1000_gpio.h>
+
+#include <linux/slab.h>
+#include <linux/mm.h>
+
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+
+struct i2c_au1x00gpio
+{
+ struct i2c_au1x00gpio *next;
+
+ short scl_gpio;
+ short sda_gpio;
+
+ unsigned long scl_mask;
+ unsigned long sda_mask;
+
+ struct i2c_adapter adapter;
+ struct i2c_algo_bit_data bit_au1x00gpio_data;
+};
+
+static struct i2c_au1x00gpio *adapter_list;
+
+
+
+/* ----- global defines ----------------------------------------------- */
+#define DEB(x) /* should be reasonable open, close &c. */
+#define DEB2(x) /* low level debugging - very slow */
+#define DEBE(x) x /* error messages */
+
+/* ----- printer port defines ------------------------------------------*/
+
+/* ----- local functions ---------------------------------------------- */
+
+
+//-- Primary GPIO
+static void bit_au1x00gpio_setscl(void *data, int state)
+{
+ struct i2c_au1x00gpio * adapter = (struct i2c_au1x00gpio *)data;
+ if (state)
+ au_writel(adapter->scl_mask, SYS_TRIOUTCLR); // Disable Driver: Switch off Transistor => 1
+ else
+ au_writel(adapter->scl_mask, SYS_OUTPUTCLR); // Clear Output and switch on Transistor => 0
+}
+
+
+static void bit_au1x00gpio_setsda(void *data, int state)
+{
+ struct i2c_au1x00gpio * adapter = (struct i2c_au1x00gpio *)data;
+ if (state)
+ au_writel(adapter->sda_mask, SYS_TRIOUTCLR);
+ else
+ au_writel(adapter->sda_mask, SYS_OUTPUTCLR);
+}
+
+
+static int bit_au1x00gpio_getscl(void *data)
+{
+ struct i2c_au1x00gpio * adapter = (struct i2c_au1x00gpio *)data;
+ return (au_readl(SYS_PINSTATERD) & adapter->scl_mask) ? 1 : 0;
+}
+
+
+static int bit_au1x00gpio_getsda(void *data)
+{
+ struct i2c_au1x00gpio * adapter = (struct i2c_au1x00gpio *)data;
+ return (au_readl(SYS_PINSTATERD) & adapter->sda_mask) ? 1 : 0;
+}
+
+
+
+
+/*--
+ *-- Functions for accessing GPIO-2
+ *--
+ */
+static void bit_au1x00gpio2_setscl(void *data, int state)
+{
+ struct i2c_au1x00gpio * adapter = (struct i2c_au1x00gpio *)data;
+ if (state)
+ {
+ au_writel(au_readl(GPIO2_DIR) & ~adapter->scl_mask, GPIO2_DIR);
+ }
+ else
+ {
+ au_writel(au_readl(GPIO2_OUTPUT) & ~adapter->scl_mask, GPIO2_OUTPUT);
+ au_writel(au_readl(GPIO2_DIR) | adapter->scl_mask, GPIO2_DIR);
+ }
+}
+
+static void bit_au1x00gpio2_setsda(void *data, int state)
+{
+ struct i2c_au1x00gpio * adapter = (struct i2c_au1x00gpio *)data;
+ if (state)
+ {
+ au_writel(au_readl(GPIO2_DIR) & ~adapter->sda_mask, GPIO2_DIR);
+ }
+ else
+ {
+ au_writel(au_readl(GPIO2_OUTPUT) & ~adapter->sda_mask, GPIO2_OUTPUT);
+ au_writel(au_readl(GPIO2_DIR) | adapter->sda_mask, GPIO2_DIR);
+ }
+}
+
+static int bit_au1x00gpio2_getscl(void *data)
+{
+ struct i2c_au1x00gpio * adapter = (struct i2c_au1x00gpio *)data;
+ return (au_readl(GPIO2_PINSTATE) & adapter->scl_mask) ? 1 : 0;
+}
+
+static int bit_au1x00gpio2_getsda(void *data)
+{
+ struct i2c_au1x00gpio * adapter = (struct i2c_au1x00gpio *)data;
+ return (au_readl(GPIO2_PINSTATE) & adapter->sda_mask) ? 1 : 0;
+}
+
+
+
+static int check_i2c_au1x00gpio_adapter(struct i2c_au1x00gpio *adapter)
+{
+ int state = 0;
+
+ adapter->bit_au1x00gpio_data.setsda (adapter, 1);
+ adapter->bit_au1x00gpio_data.setscl (adapter, 1);
+
+ if (adapter->bit_au1x00gpio_data.getsda(adapter)==0)
+ {
+ printk ("i2c-au1x00gpio: sda line should read 1 but reads 0\n");
+ state = -1;
+ }
+ if (adapter->bit_au1x00gpio_data.getscl(adapter)==0)
+ {
+ printk ("i2c-au1x00gpio: scl line should read 1 but reads 0\n");
+ state = -1;
+ }
+
+
+ adapter->bit_au1x00gpio_data.setsda (adapter, 0);
+ adapter->bit_au1x00gpio_data.setscl (adapter, 0);
+
+ if (adapter->bit_au1x00gpio_data.getsda(adapter)==1)
+ {
+ printk ("i2c-au1x00gpio: sda line should read 0 but reads 1\n");
+ state = -1;
+ }
+ if (adapter->bit_au1x00gpio_data.getscl(adapter)==1)
+ {
+ printk ("i2c-au1x00gpio: scl line should read 0 but reads 1\n");
+ state = -1;
+ }
+
+ if (state==0)
+ printk ("i2c-au1x00gpio: adapter with scl=GPIO%d,sda=GPIO%d is working\n",
+ adapter->scl_gpio, adapter->sda_gpio
+ );
+ return state;
+}
+
+
+
+#if 0
+static int bit_au1x00gpio_reg(struct i2c_client *client)
+{
+ return 0;
+}
+
+static int bit_au1x00gpio_unreg(struct i2c_client *client)
+{
+ return 0;
+}
+
+static void bit_au1x00gpio_inc_use(struct i2c_adapter *adap)
+{
+ MOD_INC_USE_COUNT;
+}
+
+static void bit_au1x00gpio_dec_use(struct i2c_adapter *adap)
+{
+ MOD_DEC_USE_COUNT;
+}
+#endif
+
+
+
+static struct i2c_algo_bit_data bit_au1x00gpio_data = {
+ .data = NULL,
+ .setsda = bit_au1x00gpio_setsda,
+ .setscl = bit_au1x00gpio_setscl,
+ .getsda = bit_au1x00gpio_getsda,
+ .getscl = bit_au1x00gpio_getscl,
+ .udelay = 80,
+ .timeout = HZ,
+};
+
+
+static struct i2c_adapter bit_au1x00gpio_ops = {
+ .owner = THIS_MODULE,
+ .name = "Au1x00 GPIO I2C adapter",
+ .id = I2C_HW_B_AU1x00GPIO,
+};
+
+
+
+/*
+ * scl_gpio:
+ * 0..31 for primary GPIO's
+ * 200..215 for secondary GPIO's
+ *
+ * sda_gpio:
+ * 0..31 for primary GPIO's
+ * 200..215 for secondary GPIO's
+ *
+ * You can even mix primary and secondary GPIO's.
+ * E.g.: i2c_au1x00gpio_create(4,206);
+ */
+
+static int i2c_au1x00gpio_create (int scl_gpio, int sda_gpio)
+{
+ if ((scl_gpio < 32 || (scl_gpio >= 200 && scl_gpio <= 215)) &&
+ (scl_gpio < 32 || (scl_gpio >= 200 && scl_gpio <= 215)))
+ {
+ struct i2c_au1x00gpio *adapter = kmalloc(sizeof(struct i2c_au1x00gpio),
+ GFP_KERNEL);
+ if (!adapter) {
+ printk(KERN_ERR "i2c-au1x00-gpio: Unable to malloc.\n");
+ return -1;
+ }
+
+ printk(KERN_DEBUG "i2c-au1x00-gpio.o: attaching to SCL=GPIO%d, SDA=GPIO%d\n",
+ scl_gpio, sda_gpio);
+
+ memset (adapter, 0, sizeof(struct i2c_au1x00gpio));
+
+ adapter->adapter = bit_au1x00gpio_ops;
+
+ adapter->adapter.algo_data = &adapter->bit_au1x00gpio_data;
+ adapter->bit_au1x00gpio_data = bit_au1x00gpio_data;
+ adapter->bit_au1x00gpio_data.data = adapter;
+
+ adapter->bit_au1x00gpio_data.data = adapter;
+
+ adapter->scl_gpio = scl_gpio;
+ adapter->sda_gpio = sda_gpio;
+
+ if (sda_gpio < 32)
+ {
+ adapter->bit_au1x00gpio_data.setsda = bit_au1x00gpio_setsda;
+ adapter->bit_au1x00gpio_data.getsda = bit_au1x00gpio_getsda;
+ adapter->sda_mask = 1<<sda_gpio;
+ }
+ else if (sda_gpio >= 200 && sda_gpio <= 215)
+ {
+ adapter->bit_au1x00gpio_data.setsda = bit_au1x00gpio2_setsda;
+ adapter->bit_au1x00gpio_data.getsda = bit_au1x00gpio2_getsda;
+ adapter->sda_mask = 1<<(sda_gpio-200);
+ }
+
+
+ if (scl_gpio < 32)
+ {
+ adapter->bit_au1x00gpio_data.setscl = bit_au1x00gpio_setscl;
+ adapter->bit_au1x00gpio_data.getscl = bit_au1x00gpio_getscl;
+ adapter->scl_mask = 1<<scl_gpio;
+ }
+ else if (scl_gpio >= 200 && scl_gpio <= 215)
+ {
+ adapter->bit_au1x00gpio_data.setscl = bit_au1x00gpio2_setscl;
+ adapter->bit_au1x00gpio_data.getscl = bit_au1x00gpio2_getscl;
+ adapter->scl_mask = 1<<(scl_gpio-200);
+ }
+
+ au_writel(0L, SYS_PININPUTEN);
+ if (check_i2c_au1x00gpio_adapter(adapter)==0)
+ {
+ adapter->bit_au1x00gpio_data.setsda (adapter, 1);
+ adapter->bit_au1x00gpio_data.setscl (adapter, 1);
+
+ if (i2c_bit_add_bus(&adapter->adapter) < 0)
+ {
+ printk(KERN_ERR "i2c-au1x00-gpio: Unable to register with I2C.\n");
+ kfree(adapter);
+ return -1; /* No good */
+ }
+
+ adapter->next = adapter_list;
+ adapter_list = adapter;
+ return 0;
+ }
+ }
+ else
+ printk(KERN_ERR "i2c-au1x00-gpio: Invalid argument scl_gpio=%d, sda_gpio=%d.\n", scl_gpio, sda_gpio);
+ return -1;
+}
+
+
+
+static void i2c_au1x00gpio_delete (int scl_gpio, int sda_gpio)
+{
+ struct i2c_au1x00gpio *adapter, *prev = NULL;
+
+ for (adapter = adapter_list; adapter; adapter = adapter->next)
+ {
+ if (adapter->scl_gpio == scl_gpio &&
+ adapter->sda_gpio == sda_gpio)
+ {
+ i2c_bit_del_bus(&adapter->adapter);
+ if (prev)
+ prev->next = adapter->next;
+ else
+ adapter_list = adapter->next;
+ kfree(adapter);
+ return;
+ }
+ prev = adapter;
+ }
+}
+
+
+
+
+
+#ifndef CONFIG_I2C_AU1X00GPIO_SCL
+#define CONFIG_I2C_AU1X00GPIO_SCL (210)
+#endif
+
+#ifndef CONFIG_I2C_AU1X00GPIO_SDA
+#define CONFIG_I2C_AU1X00GPIO_SDA (9)
+#endif
+
+static int au1x00gpiopin_scl = CONFIG_I2C_AU1X00GPIO_SCL;
+static int au1x00gpiopin_sda = CONFIG_I2C_AU1X00GPIO_SDA;
+
+
+
+static int __init i2c_bit_au1x00gpio_init(void)
+{
+ printk(KERN_INFO "i2c-au1x00gpio.o: i2c Au1x00 GPIO adapter module version\n");
+
+ if (i2c_au1x00gpio_create (au1x00gpiopin_scl, au1x00gpiopin_sda) == 0)
+ {
+ printk(KERN_INFO "i2c-au1x00gpio.o: registered I2C-Bus for GPIO%d,GPIO%d\n",
+ au1x00gpiopin_scl, au1x00gpiopin_sda
+ );
+ return 0;
+ }
+ printk(KERN_INFO "i2c-au1x00gpio.o: failed to register I2C-Bus for GPIO%d,GPIO%d\n",
+ au1x00gpiopin_scl, au1x00gpiopin_sda
+ );
+ return -1;
+}
+
+
+static void __exit i2c_bit_au1x00gpio_exit(void)
+{
+ i2c_au1x00gpio_delete (au1x00gpiopin_scl, au1x00gpiopin_sda);
+}
+
+module_param(au1x00gpiopin_scl, int, 0644);
+MODULE_PARM_DESC(au1x00gpiopin_scl, "GPIO pin number used for SCL pin.");
+
+module_param(au1x00gpiopin_sda, int, 0644);
+MODULE_PARM_DESC(au1x00gpiopin_sda, "GPIO pin number used for SDA pin.");
+
+MODULE_AUTHOR("Michael Stickel <michael@xxxxxxxxx>");
+MODULE_DESCRIPTION("I2C-Bus adapter routines for Au1x00 GPIO adapter.");
+MODULE_LICENSE("GPL");
+
+module_init(i2c_bit_au1x00gpio_init);
+module_exit(i2c_bit_au1x00gpio_exit);
diff -urN linux-2.6.19/include/linux/i2c-id.h linux-2.6.19.new/include/linux/i2c-id.h
--- linux-2.6.19/include/linux/i2c-id.h 2006-11-29 22:57:37.000000000 +0100
+++ linux-2.6.19.new/include/linux/i2c-id.h 2006-12-28 03:12:15.000000000 +0100
@@ -231,6 +231,9 @@
/* --- Au1550 PSC adapters adapters */
#define I2C_HW_AU1550_PSC 0x1b0000
+/* --- Au1x00 i2c GPIO adapter */
+#define I2C_HW_B_AU1x00GPIO 0x1b
+
/* --- SMBus only adapters */
#define I2C_HW_SMBUS_PIIX4 0x040000
#define I2C_HW_SMBUS_ALI15X3 0x040001
