This is the thirdSCx200 patch. It adds support for an I2C bus on the
SCx200 processors. Actually the patch is threee parts:
1. A driver for the ACCESS.bus of the SCx200 CPU, this is basically an
I2C bus with some hardware state machines.
2. A driver for using two GPIO pins of the processor as an I2C bus.
3. A driver for the GPIO pins so that the I2C bus driver has something
to talk to. I have added the I2C driver to the arch/i386/kernel
directory since it is very processor specific, and I've also added
some static initializers to init/main.c so that the GPIO
initialization is run before any drivers. Does this look ok?
I also have some more patches for my specific SCx200 board, and also
some IDE patches that probably should end up in the main kernel, but I
will sit on those for a while since they are not as well tested yet.
If anyone is inerested, please mail me.
/Christer
diff -urw ./linux/arch/i386/config.in.orig ./linux/arch/i386/config.in
--- ./linux/arch/i386/config.in.orig Sun Jun 30 15:15:24 2002
+++ ./linux/arch/i386/config.in Sun Jun 30 15:16:23 2002
@@ -238,6 +238,11 @@
fi
fi
+tristate 'NatSemi SCx200 GPIO support' CONFIG_SCx200_GPIO
+if [ "$CONFIG_SCx200_GPIO" = "y" ]; then
+ define_bool CONFIG_SCx200 y
+fi
+
source drivers/pci/Config.in
bool 'EISA support' CONFIG_EISA
diff -urw ./linux/arch/i386/kernel/Makefile.orig ./linux/arch/i386/kernel/Makefile
--- ./linux/arch/i386/kernel/Makefile.orig Sun Jun 30 15:15:24 2002
+++ ./linux/arch/i386/kernel/Makefile Sun Jun 30 15:16:33 2002
@@ -41,4 +41,8 @@
obj-$(CONFIG_X86_IO_APIC) += io_apic.o acpitable.o
obj-$(CONFIG_X86_VISWS_APIC) += visws_apic.o
+obj-$(CONFIG_SCx200) += scx200.o
+export-objs += scx200_gpio.o
+obj-$(CONFIG_SCx200_GPIO) += scx200_gpio.o
+
include $(TOPDIR)/Rules.make
diff -urw ./linux/arch/i386/kernel/scx200.c.orig ./linux/arch/i386/kernel/scx200.c
--- ./linux/arch/i386/kernel/scx200.c.orig Sun Jun 30 15:15:29 2002
+++ ./linux/arch/i386/kernel/scx200.c Sun Jun 30 15:17:24 2002
@@ -0,0 +1,31 @@
+/* linux/arch/i386/kernel/scx200.c
+
+ Copyright (c) 2001,2002 Christer Weinigel <[email protected]>
+
+ Make sure that the SCx200 specific initializations are run before
+ any drivers are initialized. This is also a good place to add any
+ board specific initializers. */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+
+extern int scx200_gpio_init(void);
+extern int scx200_nano_init(void);
+
+int __init scx200_init(void)
+{
+#ifdef CONFIG_SCx200_GPIO
+ scx200_gpio_init();
+#endif
+}
+
+/*
+ Local variables:
+ compile-command: "make -k -C ../../.. SUBDIRS=arch/i386/kernel bzImage"
+ c-basic-offset: 8
+ End:
+*/
diff -urw ./linux/arch/i386/kernel/scx200_gpio.c.orig ./linux/arch/i386/kernel/scx200_gpio.c
--- ./linux/arch/i386/kernel/scx200_gpio.c.orig Sun Jun 30 15:15:29 2002
+++ ./linux/arch/i386/kernel/scx200_gpio.c Sun Jun 30 15:18:30 2002
@@ -0,0 +1,130 @@
+/* linux/arch/i386/kernel/scx200_gpio.c
+
+ Copyright (c) 2001,2002 Christer Weinigel <[email protected]>
+
+ National Semiconductor SCx200 GPIO support. */
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/pci.h>
+
+#include <linux/scx200.h>
+#include <linux/scx200_gpio.h>
+
+#define NAME "scx200_gpio"
+
+MODULE_AUTHOR("Christer Weinigel <[email protected]>");
+MODULE_DESCRIPTION("NatSemi SCx200 GPIO Driver");
+MODULE_LICENSE("GPL");
+
+unsigned scx200_gpio_base = 0;
+u32 scx200_gpio_shadow[2];
+
+spinlock_t scx200_gpio_lock = SPIN_LOCK_UNLOCKED;
+static spinlock_t scx200_gpio_config_lock = SPIN_LOCK_UNLOCKED;
+
+u32 scx200_gpio_configure(int index, u32 mask, u32 bits)
+{
+ u32 config, new_config;
+ unsigned long flags;
+
+ spin_lock_irqsave(&scx200_gpio_config_lock, flags);
+
+ outl(index, scx200_gpio_base + 0x20);
+ config = inl(scx200_gpio_base + 0x24);
+
+ new_config = (config & mask) | bits;
+ outl(new_config, scx200_gpio_base + 0x24);
+
+ spin_unlock_irqrestore(&scx200_gpio_config_lock, flags);
+
+ return config;
+}
+
+void scx200_gpio_dump(unsigned index)
+{
+ u32 config = scx200_gpio_configure(index, ~0, 0);
+ printk(KERN_DEBUG "GPIO%02u: 0x%08lx", index, (unsigned long)config);
+
+ if (config & 1)
+ printk(" OE"); /* output enabled */
+ else
+ printk(" TS"); /* tristate */
+ if (config & 2)
+ printk(" PP"); /* push pull */
+ else
+ printk(" OD"); /* open drain */
+ if (config & 4)
+ printk(" PUE"); /* pull up enabled */
+ else
+ printk(" PUD"); /* pull up disabled */
+ if (config & 8)
+ printk(" LOCKED"); /* locked */
+ if (config & 16)
+ printk(" LEVEL"); /* level input */
+ else
+ printk(" EDGE"); /* edge input */
+ if (config & 32)
+ printk(" HI"); /* trigger on rising edge */
+ else
+ printk(" LO"); /* trigger on falling edge */
+ if (config & 64)
+ printk(" DEBOUNCE"); /* debounce */
+ printk("\n");
+}
+
+int __init scx200_gpio_init(void)
+{
+ struct pci_dev *bridge;
+ int bank;
+ unsigned base;
+
+ printk(KERN_DEBUG NAME ": NatSemi SCx200 GPIO Driver\n");
+
+ if ((bridge = pci_find_device(PCI_VENDOR_ID_NS,
+ PCI_DEVICE_ID_NS_SCx200_BRIDGE,
+ NULL)) == NULL)
+ return -ENODEV;
+
+ base = pci_resource_start(bridge, 0);
+ printk(KERN_INFO NAME ": GPIO base 0x%x\n", base);
+
+ if (request_region(base, SCx200_GPIO_SIZE, "NatSemi SCx200 GPIO") == 0) {
+ printk(KERN_ERR NAME ": can't allocate I/O for GPIOs\n");
+ return -EBUSY;
+ }
+
+ scx200_gpio_base = base;
+
+ /* read the current values driven on the GPIO signals */
+ for (bank = 0; bank < 2; ++bank)
+ scx200_gpio_shadow[bank] = inl(scx200_gpio_base + 0x10 * bank);
+
+ return 0;
+}
+
+#ifdef MODULE
+void __exit scx200_gpio_cleanup(void)
+{
+ release_region(scx200_gpio_base, SCx200_GPIO_SIZE);
+}
+
+module_init(scx200_gpio_init);
+module_exit(scx200_gpio_cleanup);
+#endif MODULE
+
+EXPORT_SYMBOL(scx200_gpio_base);
+EXPORT_SYMBOL(scx200_gpio_shadow);
+EXPORT_SYMBOL(scx200_gpio_lock);
+EXPORT_SYMBOL(scx200_gpio_configure);
+EXPORT_SYMBOL(scx200_gpio_dump);
+
+/*
+ Local variables:
+ compile-command: "make -k -C ../../.. SUBDIRS=arch/i386/kernel modules"
+ c-basic-offset: 8
+ End:
+*/
diff -urw ./linux/drivers/i2c/Config.in.orig ./linux/drivers/i2c/Config.in
--- ./linux/drivers/i2c/Config.in.orig Mon Feb 25 20:37:57 2002
+++ ./linux/drivers/i2c/Config.in Sun Jun 30 15:19:07 2002
@@ -13,6 +13,12 @@
dep_tristate ' Philips style parallel port adapter' CONFIG_I2C_PHILIPSPAR $CONFIG_I2C_ALGOBIT $CONFIG_PARPORT
dep_tristate ' ELV adapter' CONFIG_I2C_ELV $CONFIG_I2C_ALGOBIT
dep_tristate ' Velleman K9000 adapter' CONFIG_I2C_VELLEMAN $CONFIG_I2C_ALGOBIT
+ dep_tristate ' NatSemi SCx200 I2C using GPIO pins' CONFIG_SCx200_I2C $CONFIG_SCx200_GPIO $CONFIG_I2C_ALGOBIT
+ if [ "$CONFIG_SCx200_I2C" != "n" ]; then
+ int ' GPIO pin used for SCL' CONFIG_SCx200_I2C_SCL 12
+ int ' GPIO pin used for SDA' CONFIG_SCx200_I2C_SDA 13
+ fi
+ dep_tristate ' NatSemi SCx200 ACCESS.bus' CONFIG_SCx200_ACB $CONFIG_I2C
fi
dep_tristate 'I2C PCF 8584 interfaces' CONFIG_I2C_ALGOPCF $CONFIG_I2C
diff -urw ./linux/drivers/i2c/Makefile.orig ./linux/drivers/i2c/Makefile
--- ./linux/drivers/i2c/Makefile.orig Mon Feb 25 20:37:57 2002
+++ ./linux/drivers/i2c/Makefile Sun Jun 30 15:19:07 2002
@@ -18,6 +18,8 @@
obj-$(CONFIG_ITE_I2C_ALGO) += i2c-algo-ite.o
obj-$(CONFIG_ITE_I2C_ADAP) += i2c-adap-ite.o
obj-$(CONFIG_I2C_PROC) += i2c-proc.o
+obj-$(CONFIG_SCx200_I2C) += scx200_i2c.o
+obj-$(CONFIG_SCx200_ACB) += scx200_acb.o
obj-$(CONFIG_I2C_KEYWEST) += i2c-keywest.o
# This is needed for automatic patch generation: sensors code starts here
diff -urw ./linux/drivers/i2c/scx200_acb.c.orig ./linux/drivers/i2c/scx200_acb.c
--- ./linux/drivers/i2c/scx200_acb.c.orig Sun Jun 30 15:19:07 2002
+++ ./linux/drivers/i2c/scx200_acb.c Sun Jun 30 15:19:07 2002
@@ -0,0 +1,581 @@
+/* linux/drivers/i2c/scx200_acb.c
+
+ Copyright (c) 2001,2002 Christer Weinigel <[email protected]>
+
+ National Semiconductor SCx200 ACCESS.bus support
+
+ Based on i2c-keywest.c which is:
+ Copyright (c) 2001 Benjamin Herrenschmidt <[email protected]>
+ Copyright (c) 2000 Philip Edelbrock <[email protected]>
+
+ 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.
+
+*/
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/smp_lock.h>
+#include <linux/pci.h>
+#include <asm/io.h>
+
+#include <linux/scx200.h>
+
+#define NAME "scx200_acb"
+
+MODULE_AUTHOR("Christer Weinigel <[email protected]>");
+MODULE_DESCRIPTION("NatSemi SCx200 ACCESS.bus Driver");
+MODULE_LICENSE("GPL");
+
+#define MAX_DEVICES 4
+static int base[MAX_DEVICES] = { 0x840 };
+MODULE_PARM(base, "1-4i");
+MODULE_PARM_DESC(base, "Base addresses for the ACCESS.bus controllers");
+
+#define DEBUG 0
+
+#if DEBUG
+#define DBG(x...) printk(KERN_DEBUG NAME ": " x)
+#else
+#define DBG(x...)
+#endif
+
+/* The hardware supports interrupt driven mode too, but I haven't
+ implemented that. */
+#define POLLED_MODE 1
+#define POLL_TIMEOUT (HZ)
+
+enum scx200_acb_state {
+ state_idle,
+ state_address,
+ state_command,
+ state_repeat_start,
+ state_quick,
+ state_read,
+ state_write,
+};
+
+static const char *scx200_acb_state_name[] = {
+ "idle",
+ "address",
+ "command",
+ "repeat_start",
+ "quick",
+ "read",
+ "write",
+};
+
+/* Physical interface */
+struct scx200_acb_iface
+{
+ struct scx200_acb_iface *next;
+ struct i2c_adapter adapter;
+ unsigned base;
+ struct semaphore sem;
+
+ /* State machine data */
+ enum scx200_acb_state state;
+ int result;
+ u8 address_byte;
+ u8 command;
+ u8 *ptr;
+ char needs_reset;
+ unsigned len;
+};
+
+/* Register Definitions */
+#define ACBSDA (iface->base + 0)
+#define ACBST (iface->base + 1)
+#define ACBST_SDAST 0x40 /* SDA Status */
+#define ACBST_BER 0x20
+#define ACBST_NEGACK 0x10 /* Negative Acknowledge */
+#define ACBST_STASTR 0x08 /* Stall After Start */
+#define ACBST_MASTER 0x02
+#define ACBCST (iface->base + 2)
+#define ACBCST_BB 0x02
+#define ACBCTL1 (iface->base + 3)
+#define ACBCTL1_STASTRE 0x80
+#define ACBCTL1_NMINTE 0x40
+#define ACBCTL1_ACK 0x10
+#define ACBCTL1_STOP 0x02
+#define ACBCTL1_START 0x01
+#define ACBADDR (iface->base + 4)
+#define ACBCTL2 (iface->base + 5)
+#define ACBCTL2_ENABLE 0x01
+
+/************************************************************************/
+
+static void scx200_acb_machine(struct scx200_acb_iface *iface, u8 status)
+{
+ const char *errmsg;
+
+ DBG("state %s, status = 0x%02x\n",
+ scx200_acb_state_name[iface->state], status);
+
+ if (status & ACBST_BER) {
+ errmsg = "bus error";
+ goto error;
+ }
+ if (!(status & ACBST_MASTER)) {
+ errmsg = "not master";
+ goto error;
+ }
+ if (status & ACBST_NEGACK)
+ goto negack;
+
+ switch (iface->state) {
+ case state_idle:
+ printk(KERN_WARNING NAME ": %s, interrupt in idle state\n",
+ iface->adapter.name);
+ break;
+
+ case state_address:
+ /* Do a pointer write first */
+ outb(iface->address_byte & ~1, ACBSDA);
+
+ iface->state = state_command;
+ break;
+
+ case state_command:
+ outb(iface->command, ACBSDA);
+
+ if (iface->address_byte & 1)
+ iface->state = state_repeat_start;
+ else
+ iface->state = state_write;
+ break;
+
+ case state_repeat_start:
+ outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
+ /* fallthrough */
+
+ case state_quick:
+ if (iface->address_byte & 1) {
+ if (iface->len == 1)
+ outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
+ else
+ outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
+ outb(iface->address_byte, ACBSDA);
+
+ iface->state = state_read;
+ } else {
+ outb(iface->address_byte, ACBSDA);
+
+ iface->state = state_write;
+ }
+ break;
+
+ case state_read:
+ /* Set ACK if receiving the last byte */
+ if (iface->len == 1)
+ outb(inb(ACBCTL1) | ACBCTL1_ACK, ACBCTL1);
+ else
+ outb(inb(ACBCTL1) & ~ACBCTL1_ACK, ACBCTL1);
+
+ *iface->ptr++ = inb(ACBSDA);
+ --iface->len;
+
+ if (iface->len == 0) {
+ iface->result = 0;
+ iface->state = state_idle;
+ outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
+ }
+
+ break;
+
+ case state_write:
+ if (iface->len == 0) {
+ iface->result = 0;
+ iface->state = state_idle;
+ outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
+ break;
+ }
+
+ outb(*iface->ptr++, ACBSDA);
+ --iface->len;
+
+ break;
+ }
+
+ return;
+
+ negack:
+ DBG("%s: negative acknowledge in state %s\n",
+ name, scx200_acb_state_name[iface->state]);
+
+ iface->state = state_idle;
+ iface->result = -ENXIO;
+
+ outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
+ outb(ACBST_STASTR | ACBST_NEGACK, ACBST);
+ return;
+
+ error:
+ printk(KERN_ERR NAME ": %s, %s in state %s\n", iface->adapter.name,
+ errmsg, scx200_acb_state_name[iface->state]);
+
+ iface->state = state_idle;
+ iface->result = -EIO;
+ iface->needs_reset = 1;
+}
+
+static void scx200_acb_timeout(struct scx200_acb_iface *iface)
+{
+ printk(KERN_ERR NAME ": %s, timeout in state %s\n",
+ iface->adapter.name, scx200_acb_state_name[iface->state]);
+
+ iface->state = state_idle;
+ iface->result = -EIO;
+ iface->needs_reset = 1;
+}
+
+#ifdef POLLED_MODE
+static void scx200_acb_poll(struct scx200_acb_iface *iface)
+{
+ u8 status = 0;
+ unsigned long timeout;
+
+ timeout = jiffies + POLL_TIMEOUT;
+ while (time_before(jiffies, timeout)) {
+ status = inb(ACBST);
+ if ((status & (ACBST_SDAST|ACBST_BER|ACBST_NEGACK)) != 0) {
+ scx200_acb_machine(iface, status);
+ return;
+ }
+ current->policy |= SCHED_YIELD;
+ schedule();
+ }
+
+ scx200_acb_timeout(iface);
+}
+#endif /* POLLED_MODE */
+
+static void scx200_acb_reset(struct scx200_acb_iface *iface)
+{
+ /* Disable the ACCESS.bus device and Configure the SCL
+ frequency: 16 clock cycles */
+ outb(0x70, ACBCTL2);
+ /* Polling mode */
+ outb(0, ACBCTL1);
+ /* Disable slave address */
+ outb(0, ACBADDR);
+ /* Enable the ACCESS.bus device */
+ outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
+ /* Free STALL after START */
+ outb(inb(ACBCTL1) & ~(ACBCTL1_STASTRE | ACBCTL1_NMINTE), ACBCTL1);
+ /* Send a STOP */
+ outb(inb(ACBCTL1) | ACBCTL1_STOP, ACBCTL1);
+ /* Clear BER, NEGACK and STASTR bits */
+ outb(ACBST_BER | ACBST_NEGACK | ACBST_STASTR, ACBST);
+ /* Clear BB bit */
+ outb(inb(ACBCST) | ACBCST_BB, ACBCST);
+}
+
+static s32 scx200_acb_smbus_xfer(struct i2c_adapter *adapter,
+ u16 address, unsigned short flags,
+ char rw, u8 command, int size,
+ union i2c_smbus_data *data)
+{
+ struct scx200_acb_iface *iface = adapter->data;
+ int len;
+ u8 *buffer;
+ u16 cur_word;
+ int rc;
+
+ switch (size) {
+ case I2C_SMBUS_QUICK:
+ len = 0;
+ buffer = NULL;
+ break;
+ case I2C_SMBUS_BYTE:
+ if (rw == I2C_SMBUS_READ) {
+ len = 1;
+ buffer = &data->byte;
+ } else {
+ len = 1;
+ buffer = &command;
+ }
+ break;
+ case I2C_SMBUS_BYTE_DATA:
+ len = 1;
+ buffer = &data->byte;
+ break;
+ case I2C_SMBUS_WORD_DATA:
+ len = 2;
+ cur_word = cpu_to_le16(data->word);
+ buffer = (u8 *)&cur_word;
+ break;
+ case I2C_SMBUS_BLOCK_DATA:
+ len = data->block[0];
+ buffer = &data->block[1];
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ DBG("%s: size=%d, address=0x%x, command=0x%x, len=%d, read=%d\n",
+ name, size, address, command, len, rw == I2C_SMBUS_READ);
+
+ if (!len && rw == I2C_SMBUS_READ) {
+ printk(KERN_WARNING NAME ": %s, zero length read\n",
+ adapter->name);
+ return -EINVAL;
+ }
+
+ if (len && !buffer) {
+ printk(KERN_WARNING NAME ": %s, nonzero length but no buffer\n", adapter->name);
+ return -EFAULT;
+ }
+
+ down(&iface->sem);
+
+ iface->address_byte = address<<1;
+ if (rw == I2C_SMBUS_READ)
+ iface->address_byte |= 1;
+ iface->command = command;
+ iface->ptr = buffer;
+ iface->len = len;
+ iface->result = -EINVAL;
+ iface->needs_reset = 0;
+
+ outb(inb(ACBCTL1) | ACBCTL1_START, ACBCTL1);
+
+ if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE)
+ iface->state = state_quick;
+ else
+ iface->state = state_address;
+
+#ifdef POLLED_MODE
+ while (iface->state != state_idle)
+ scx200_acb_poll(iface);
+#else /* POLLED_MODE */
+#error Interrupt driven mode not implemented
+#endif /* POLLED_MODE */
+
+ if (iface->needs_reset)
+ scx200_acb_reset(iface);
+
+ rc = iface->result;
+
+ up(&iface->sem);
+
+ if (rc == 0 && size == I2C_SMBUS_WORD_DATA && rw == I2C_SMBUS_READ)
+ data->word = le16_to_cpu(cur_word);
+
+#if DEBUG
+ printk(KERN_DEBUG "%s: transfer done, result: %d", name, rc);
+ if (buffer) {
+ int i;
+ printk(" data:");
+ for (i = 0; i < len; ++i)
+ printk(" %02x", buffer[i]);
+ printk("\n");
+ }
+#endif
+ DBG("\n");
+
+ return rc;
+}
+
+static u32 scx200_acb_func(struct i2c_adapter *adapter)
+{
+ return I2C_FUNC_SMBUS_QUICK | I2C_FUNC_SMBUS_BYTE |
+ I2C_FUNC_SMBUS_BYTE_DATA | I2C_FUNC_SMBUS_WORD_DATA |
+ I2C_FUNC_SMBUS_BLOCK_DATA;
+}
+
+static int scx200_acb_reg(struct i2c_client *client)
+{
+ return 0;
+}
+
+static int scx200_acb_unreg(struct i2c_client *client)
+{
+ return 0;
+}
+
+static void scx200_acb_inc_use(struct i2c_adapter *adapter)
+{
+ MOD_INC_USE_COUNT;
+}
+
+static void scx200_acb_dec_use(struct i2c_adapter *adapter)
+{
+ MOD_DEC_USE_COUNT;
+}
+
+/* For now, we only handle combined mode (smbus) */
+static struct i2c_algorithm scx200_acb_algorithm = {
+ name: "NatSemi SCx200 ACCESS.bus",
+ id: I2C_ALGO_SMBUS,
+ smbus_xfer: scx200_acb_smbus_xfer,
+ functionality: scx200_acb_func,
+};
+
+struct scx200_acb_iface *scx200_acb_list;
+
+int scx200_acb_probe(struct scx200_acb_iface *iface)
+{
+ u8 val;
+
+ /* Disable the ACCESS.bus device and Configure the SCL
+ frequency: 16 clock cycles */
+ outb(0x70, ACBCTL2);
+
+ if (inb(ACBCTL2) != 0x70) {
+ DBG("%s: ACBCTL2 readback failed\n", name);
+ return -ENXIO;
+ }
+
+ outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
+
+ val = inb(ACBCTL1);
+ if (val) {
+ DBG("%s: disabled, but ACBCTL1=0x%02x\n", name, val);
+ return -ENXIO;
+ }
+
+ outb(inb(ACBCTL2) | ACBCTL2_ENABLE, ACBCTL2);
+
+ outb(inb(ACBCTL1) | ACBCTL1_NMINTE, ACBCTL1);
+
+ val = inb(ACBCTL1);
+ if ((val & ACBCTL1_NMINTE) != ACBCTL1_NMINTE) {
+ DBG("%s: enabled, but NMINTE won't be set, ACBCTL1=0x%02x\n",
+ name, val);
+ return -ENXIO;
+ }
+
+ return 0;
+}
+
+static int __init scx200_acb_create(int base, int index)
+{
+ struct scx200_acb_iface *iface;
+ struct i2c_adapter *adapter;
+ int rc = 0;
+ char description[64];
+
+ iface = kmalloc(sizeof(*iface), GFP_KERNEL);
+ if (!iface) {
+ printk(KERN_ERR NAME ": can't allocate memory\n");
+ rc = -ENOMEM;
+ goto errout;
+ }
+
+ memset(iface, 0, sizeof(*iface));
+ adapter = &iface->adapter;
+ adapter->data = iface;
+ sprintf(adapter->name, "SCx200 ACB%d", index);
+ adapter->id = I2C_ALGO_SMBUS;
+ adapter->algo = &scx200_acb_algorithm;
+ adapter->inc_use = scx200_acb_inc_use;
+ adapter->dec_use = scx200_acb_dec_use;
+ adapter->client_register = scx200_acb_reg;
+ adapter->client_unregister = scx200_acb_unreg;
+
+ init_MUTEX(&iface->sem);
+
+ sprintf(description, "NatSemi SCx200 ACCESS.bus [%s]", adapter->name);
+ if (request_region(base, 8, description) == 0) {
+ printk(KERN_ERR NAME ": %s, can't allocate io 0x%x-0x%x\n",
+ adapter->name, base, base + 8-1);
+ rc = -EBUSY;
+ goto errout;
+ }
+ iface->base = base;
+
+ rc = scx200_acb_probe(iface);
+ if (rc) {
+ printk(KERN_WARNING NAME ": %s, probe failed\n", adapter->name);
+ goto errout;
+ }
+
+ scx200_acb_reset(iface);
+
+ if (i2c_add_adapter(adapter) < 0) {
+ printk(KERN_ERR NAME ": %s, failed to register\n", adapter->name);
+ rc = -ENODEV;
+ goto errout;
+ }
+
+ lock_kernel();
+ iface->next = scx200_acb_list;
+ scx200_acb_list = iface;
+ unlock_kernel();
+
+ return 0;
+
+ errout:
+ if (iface) {
+ if (iface->base)
+ release_region(iface->base, 8);
+ kfree(iface);
+ }
+ return rc;
+}
+
+static int __init scx200_acb_init(void)
+{
+ int i;
+ int rc;
+
+ printk(KERN_DEBUG NAME ": NatSemi SCx200 ACCESS.bus Driver\n");
+
+ /* Verify that this really is a SCx200 processor */
+ if (pci_find_device(PCI_VENDOR_ID_NS,
+ PCI_DEVICE_ID_NS_SCx200_BRIDGE,
+ NULL) == NULL)
+ return -ENODEV;
+
+ rc = -ENXIO;
+ for (i = 0; i < MAX_DEVICES; ++i) {
+ if (base[i] > 0)
+ rc = scx200_acb_create(base[i], i);
+ }
+ if (scx200_acb_list)
+ return 0;
+ return rc;
+}
+
+static void __exit scx200_acb_cleanup(void)
+{
+ struct scx200_acb_iface *iface;
+ lock_kernel();
+ while ((iface = scx200_acb_list) != NULL) {
+ scx200_acb_list = iface->next;
+ unlock_kernel();
+
+ i2c_del_adapter(&iface->adapter);
+ release_region(iface->base, 8);
+ kfree(iface);
+ lock_kernel();
+ }
+ unlock_kernel();
+}
+
+module_init(scx200_acb_init);
+module_exit(scx200_acb_cleanup);
+
+/*
+ Local variables:
+ compile-command: "make -k -C ../.. SUBDIRS=drivers/i2c modules"
+ c-basic-offset: 8
+ End:
+*/
+
diff -urw ./linux/drivers/i2c/scx200_i2c.c.orig ./linux/drivers/i2c/scx200_i2c.c
--- ./linux/drivers/i2c/scx200_i2c.c.orig Sun Jun 30 15:19:07 2002
+++ ./linux/drivers/i2c/scx200_i2c.c Sun Jun 30 15:19:07 2002
@@ -0,0 +1,156 @@
+/* linux/drivers/i2c/scx200_i2c.c
+
+ Copyright (c) 2001,2002 Christer Weinigel <[email protected]>
+
+ National Semiconductor SCx200 I2C bus on GPIO pins
+
+ Based on i2c-velleman.c Copyright (C) 1995-96, 2000 Simon G. Vogl
+
+ 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.
+*/
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/init.h>
+#include <linux/i2c.h>
+#include <linux/i2c-algo-bit.h>
+#include <asm/io.h>
+
+#include <linux/scx200_gpio.h>
+
+#define NAME "scx200_i2c"
+
+MODULE_AUTHOR("Christer Weinigel <[email protected]>");
+MODULE_DESCRIPTION("NatSemi SCx200 I2C Driver");
+MODULE_LICENSE("GPL");
+
+MODULE_PARM(scl, "i");
+MODULE_PARM_DESC(scl, "GPIO line for SCL");
+MODULE_PARM(sda, "i");
+MODULE_PARM_DESC(sda, "GPIO line for SDA");
+
+static int scl = CONFIG_SCx200_I2C_SCL;
+static int sda = CONFIG_SCx200_I2C_SDA;
+
+static void scx200_i2c_setscl(void *data, int state)
+{
+ scx200_gpio_set(scl, state);
+}
+
+static void scx200_i2c_setsda(void *data, int state)
+{
+ scx200_gpio_set(sda, state);
+}
+
+static int scx200_i2c_getscl(void *data)
+{
+ return scx200_gpio_get(scl);
+}
+
+static int scx200_i2c_getsda(void *data)
+{
+ return scx200_gpio_get(sda);
+}
+
+static int scx200_i2c_reg(struct i2c_client *client)
+{
+ return 0;
+}
+
+static int scx200_i2c_unreg(struct i2c_client *client)
+{
+ return 0;
+}
+
+static void scx200_i2c_inc_use(struct i2c_adapter *adap)
+{
+ MOD_INC_USE_COUNT;
+}
+
+static void scx200_i2c_dec_use(struct i2c_adapter *adap)
+{
+ MOD_DEC_USE_COUNT;
+}
+
+/* ------------------------------------------------------------------------
+ * Encapsulate the above functions in the correct operations structure.
+ * This is only done when more than one hardware adapter is supported.
+ */
+
+static struct i2c_algo_bit_data scx200_i2c_data = {
+ NULL,
+ scx200_i2c_setsda,
+ scx200_i2c_setscl,
+ scx200_i2c_getsda,
+ scx200_i2c_getscl,
+ 10, 10, 100, /* waits, timeout */
+};
+
+static struct i2c_adapter scx200_i2c_ops = {
+ name: "NatSemi SCx200 I2C",
+ id: I2C_HW_B_VELLE,
+ algo_data: &scx200_i2c_data,
+ inc_use: scx200_i2c_inc_use,
+ dec_use: scx200_i2c_dec_use,
+ client_register: scx200_i2c_reg,
+ client_unregister: scx200_i2c_unreg,
+};
+
+int scx200_i2c_init(void)
+{
+ printk(KERN_DEBUG NAME ": NatSemi SCx200 I2C Driver\n");
+
+ if (!scx200_gpio_present()) {
+ printk(KERN_ERR NAME ": no SCx200 gpio pins available\n");
+ return -ENODEV;
+ }
+
+ printk(KERN_DEBUG NAME ": SCL=GPIO%02u, SDA=GPIO%02u\n",
+ scl, sda);
+
+ if (scl == -1 || sda == -1 || scl == sda) {
+ printk(KERN_ERR NAME ": scl and sda must be specified\n");
+ return -EINVAL;
+ }
+
+ /* Configure GPIOs as open collector outputs */
+ scx200_gpio_configure(scl, ~2, 5);
+ scx200_gpio_configure(sda, ~2, 5);
+
+ if (i2c_bit_add_bus(&scx200_i2c_ops) < 0) {
+ printk(KERN_ERR NAME ": adapter %s registration failed\n",
+ scx200_i2c_ops.name);
+ return -ENODEV;
+ }
+
+ return 0;
+}
+
+void scx200_i2c_cleanup(void)
+{
+ i2c_bit_del_bus(&scx200_i2c_ops);
+}
+
+module_init(scx200_i2c_init);
+module_exit(scx200_i2c_cleanup);
+
+/*
+ Local variables:
+ compile-command: "make -k -C ../.. SUBDIRS=drivers/i2c modules"
+ c-basic-offset: 8
+ End:
+*/
diff -urw ./linux/include/linux/scx200_gpio.h.orig ./linux/include/linux/scx200_gpio.h
--- ./linux/include/linux/scx200_gpio.h.orig Sun Jun 30 15:15:29 2002
+++ ./linux/include/linux/scx200_gpio.h Sun Jun 30 15:15:29 2002
@@ -0,0 +1,99 @@
+#include <linux/spinlock.h>
+
+u32 scx200_gpio_configure(int index, u32 set, u32 clear);
+void scx200_gpio_dump(unsigned index);
+
+extern unsigned scx200_gpio_base;
+extern spinlock_t scx200_gpio_lock;
+extern u32 scx200_gpio_shadow[2];
+extern u32 *dummy;
+
+#define scx200_gpio_present() (scx200_gpio_base!=0)
+
+/* Definitions to make sure I do the same thing in all functions */
+#define __SCx200_GPIO_BANK unsigned bank = index>>5
+#define __SCx200_GPIO_IOADDR unsigned short ioaddr = scx200_gpio_base+0x10*bank
+#define __SCx200_GPIO_SHADOW u32 *shadow = scx200_gpio_shadow+bank
+#define __SCx200_GPIO_INDEX index &= 31
+
+#define __SCx200_GPIO_OUT __asm__ __volatile__("outsl":"=mS" (shadow):"d" (ioaddr), "0" (shadow))
+
+/* returns the value of the GPIO pin */
+
+static inline int scx200_gpio_get(int index) {
+ __SCx200_GPIO_BANK;
+ __SCx200_GPIO_IOADDR + 0x04;
+ __SCx200_GPIO_INDEX;
+
+ return (inl(ioaddr) & (1<<index)) ? 1 : 0;
+}
+
+/* return the value driven on the GPIO signal (the value that will be
+ driven if the GPIO is configured as an output, it might not be the
+ state of the GPIO right now if the GPIO is configured as an input) */
+
+static inline int scx200_gpio_current(int index) {
+ __SCx200_GPIO_BANK;
+ __SCx200_GPIO_INDEX;
+
+ return (scx200_gpio_shadow[bank] & (1<<index)) ? 1 : 0;
+}
+
+/* drive the GPIO signal high */
+
+static inline void scx200_gpio_set_high(int index) {
+ __SCx200_GPIO_BANK;
+ __SCx200_GPIO_IOADDR;
+ __SCx200_GPIO_SHADOW;
+ __SCx200_GPIO_INDEX;
+ set_bit(index, shadow);
+ __SCx200_GPIO_OUT;
+}
+
+/* drive the GPIO signal low */
+
+static inline void scx200_gpio_set_low(int index) {
+ __SCx200_GPIO_BANK;
+ __SCx200_GPIO_IOADDR;
+ __SCx200_GPIO_SHADOW;
+ __SCx200_GPIO_INDEX;
+ clear_bit(index, shadow);
+ __SCx200_GPIO_OUT;
+}
+
+/* drive the GPIO signal to state */
+
+static inline void scx200_gpio_set(int index, int state) {
+ __SCx200_GPIO_BANK;
+ __SCx200_GPIO_IOADDR;
+ __SCx200_GPIO_SHADOW;
+ __SCx200_GPIO_INDEX;
+ if (state)
+ set_bit(index, shadow);
+ else
+ clear_bit(index, shadow);
+ __SCx200_GPIO_OUT;
+}
+
+/* toggle the GPIO signal */
+static inline void scx200_gpio_change(int index) {
+ __SCx200_GPIO_BANK;
+ __SCx200_GPIO_IOADDR;
+ __SCx200_GPIO_SHADOW;
+ __SCx200_GPIO_INDEX;
+ change_bit(index, shadow);
+ __SCx200_GPIO_OUT;
+}
+
+#undef __SCx200_GPIO_BANK
+#undef __SCx200_GPIO_IOADDR
+#undef __SCx200_GPIO_SHADOW
+#undef __SCx200_GPIO_INDEX
+#undef __SCx200_GPIO_OUT
+
+/*
+ Local variables:
+ compile-command: "make -C ../.. bzImage modules"
+ c-basic-offset: 8
+ End:
+*/
diff -urw ./linux/init/main.c.orig ./linux/init/main.c
--- ./linux/init/main.c.orig Sun Jun 30 15:15:24 2002
+++ ./linux/init/main.c Sun Jun 30 15:15:29 2002
@@ -94,6 +94,7 @@
extern void sysctl_init(void);
extern void signals_init(void);
extern int init_pcmcia_ds(void);
+extern int scx200_init(void);
extern void free_initmem(void);
@@ -521,6 +522,9 @@
#endif
#ifdef CONFIG_TC
tc_init();
+#endif
+#ifdef CONFIG_SCx200
+ scx200_init();
#endif
/* Networking initialization needs a process context */
--
"Just how much can I get away with and still go to heaven?"