patch-2.4.18 linux/drivers/i2c/i2c-keywest.c
Next file: linux/drivers/i2c/i2c-keywest.h
Previous file: linux/drivers/i2c/Makefile
Back to the patch index
Back to the overall index
- Lines: 681
- Date:
Mon Feb 4 18:47:24 2002
- Orig file:
linux.orig/drivers/i2c/i2c-keywest.c
- Orig date:
Thu Jan 1 00:00:00 1970
diff -Naur -X /home/marcelo/lib/dontdiff linux.orig/drivers/i2c/i2c-keywest.c linux/drivers/i2c/i2c-keywest.c
@@ -0,0 +1,680 @@
+/*
+ i2c Support for Apple Keywest I2C Bus Controller
+
+ Copyright (c) 2001 Benjamin Herrenschmidt <benh@kernel.crashing.org>
+
+ Original work by
+
+ Copyright (c) 2000 Philip Edelbrock <phil@stimpy.netroedge.com>
+
+ 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.
+
+ Changes:
+
+ 2001/12/13 BenH New implementation
+ 2001/12/15 BenH Add support for "byte" and "quick"
+ transfers. Add i2c_xfer routine.
+
+ My understanding of the various modes supported by keywest are:
+
+ - Dumb mode : not implemented, probably direct tweaking of lines
+ - Standard mode : simple i2c transaction of type
+ S Addr R/W A Data A Data ... T
+ - Standard sub mode : combined 8 bit subaddr write with data read
+ S Addr R/W A SubAddr A Data A Data ... T
+ - Combined mode : Subaddress and Data sequences appended with no stop
+ S Addr R/W A SubAddr S Addr R/W A Data A Data ... T
+
+ Currently, this driver uses only Standard mode for i2c xfer, and
+ smbus byte & quick transfers ; and uses StandardSub mode for
+ other smbus transfers instead of combined as we need that for the
+ sound driver to be happy
+*/
+
+#include <linux/module.h>
+#include <linux/config.h>
+#include <linux/version.h>
+#include <linux/kernel.h>
+#include <linux/ioport.h>
+#include <linux/pci.h>
+#include <linux/types.h>
+#include <linux/delay.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/mm.h>
+#include <linux/timer.h>
+#include <linux/spinlock.h>
+#include <linux/completion.h>
+
+#include <asm/io.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+#include <asm/pmac_feature.h>
+
+#include "i2c-keywest.h"
+
+#undef POLLED_MODE
+
+#define DBG(x...) do {\
+ if (debug > 0) \
+ printk(KERN_DEBUG "KW:" x); \
+ } while(0)
+
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("I2C driver for Apple's Keywest");
+MODULE_LICENSE("GPL");
+MODULE_PARM(probe, "i");
+MODULE_PARM(debug, "i");
+EXPORT_NO_SYMBOLS;
+
+int probe = 0;
+int debug = 0;
+
+static struct keywest_iface *ifaces = NULL;
+
+#ifdef POLLED_MODE
+/* This isn't fast, but will go once I implement interrupt with
+ * proper timeout
+ */
+static u8
+wait_interrupt(struct keywest_iface* iface)
+{
+ int i;
+ u8 isr;
+
+ for (i = 0; i < POLL_TIMEOUT; i++) {
+ isr = read_reg(reg_isr) & KW_I2C_IRQ_MASK;
+ if (isr != 0)
+ return isr;
+ current->state = TASK_UNINTERRUPTIBLE;
+ schedule_timeout(1);
+ }
+ return isr;
+}
+#endif /* POLLED_MODE */
+
+
+static void
+do_stop(struct keywest_iface* iface, int result)
+{
+ write_reg(reg_control, read_reg(reg_control) | KW_I2C_CTL_STOP);
+ iface->state = state_stop;
+ iface->result = result;
+}
+
+/* Main state machine for standard & standard sub mode */
+static void
+handle_interrupt(struct keywest_iface *iface, u8 isr)
+{
+ int ack;
+
+ DBG("handle_interrupt(), got: %x, status: %x, state: %d\n",
+ isr, read_reg(reg_status), iface->state);
+ if (isr == 0 && iface->state != state_stop) {
+ do_stop(iface, -1);
+ return;
+ }
+ if (isr & KW_I2C_IRQ_STOP && iface->state != state_stop) {
+ iface->result = -1;
+ iface->state = state_stop;
+ }
+ switch(iface->state) {
+ case state_addr:
+ if (!(isr & KW_I2C_IRQ_ADDR)) {
+ do_stop(iface, -1);
+ break;
+ }
+ ack = read_reg(reg_status);
+ DBG("ack on set address: %x\n", ack);
+ if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
+ do_stop(iface, -1);
+ break;
+ }
+ /* Handle rw "quick" mode */
+ if (iface->datalen == 0)
+ do_stop(iface, 0);
+ else if (iface->read_write == I2C_SMBUS_READ) {
+ iface->state = state_read;
+ if (iface->datalen > 1)
+ write_reg(reg_control, read_reg(reg_control)
+ | KW_I2C_CTL_AAK);
+ } else {
+ iface->state = state_write;
+ DBG("write byte: %x\n", *(iface->data));
+ write_reg(reg_data, *(iface->data++));
+ iface->datalen--;
+ }
+
+ break;
+ case state_read:
+ if (!(isr & KW_I2C_IRQ_DATA)) {
+ do_stop(iface, -1);
+ break;
+ }
+ *(iface->data++) = read_reg(reg_data);
+ DBG("read byte: %x\n", *(iface->data-1));
+ iface->datalen--;
+ if (iface->datalen == 0)
+ iface->state = state_stop;
+ else
+ write_reg(reg_control, 0);
+ break;
+ case state_write:
+ if (!(isr & KW_I2C_IRQ_DATA)) {
+ do_stop(iface, -1);
+ break;
+ }
+ /* Check ack status */
+ ack = read_reg(reg_status);
+ DBG("ack on data write: %x\n", ack);
+ if ((ack & KW_I2C_STAT_LAST_AAK) == 0) {
+ do_stop(iface, -1);
+ break;
+ }
+ if (iface->datalen) {
+ DBG("write byte: %x\n", *(iface->data));
+ write_reg(reg_data, *(iface->data++));
+ iface->datalen--;
+ } else
+ do_stop(iface, 0);
+ break;
+
+ case state_stop:
+ if (!(isr & KW_I2C_IRQ_STOP) && (++iface->stopretry) < 10)
+ do_stop(iface, -1);
+ else {
+ iface->state = state_idle;
+ write_reg(reg_control, 0x00);
+ write_reg(reg_ier, 0x00);
+#ifndef POLLED_MODE
+ complete(&iface->complete);
+#endif /* POLLED_MODE */
+ }
+ break;
+ }
+
+ write_reg(reg_isr, isr);
+}
+
+#ifndef POLLED_MODE
+
+/* Interrupt handler */
+static void
+keywest_irq(int irq, void *dev_id, struct pt_regs *regs)
+{
+ struct keywest_iface *iface = (struct keywest_iface *)dev_id;
+
+ spin_lock(&iface->lock);
+ del_timer(&iface->timeout_timer);
+ handle_interrupt(iface, read_reg(reg_isr));
+ if (iface->state != state_idle) {
+ iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
+ add_timer(&iface->timeout_timer);
+ }
+ spin_unlock(&iface->lock);
+}
+
+static void
+keywest_timeout(unsigned long data)
+{
+ struct keywest_iface *iface = (struct keywest_iface *)data;
+
+ DBG("timeout !\n");
+ spin_lock_irq(&iface->lock);
+ handle_interrupt(iface, read_reg(reg_isr));
+ if (iface->state != state_idle) {
+ iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
+ add_timer(&iface->timeout_timer);
+ }
+ spin_unlock(&iface->lock);
+}
+
+#endif /* POLLED_MODE */
+
+/*
+ * SMBUS-type transfer entrypoint
+ */
+static s32
+keywest_smbus_xfer( struct i2c_adapter* adap,
+ u16 addr,
+ unsigned short flags,
+ char read_write,
+ u8 command,
+ int size,
+ union i2c_smbus_data* data)
+{
+ struct keywest_chan* chan = (struct keywest_chan*)adap->data;
+ struct keywest_iface* iface = chan->iface;
+ int len;
+ u8* buffer;
+ u16 cur_word;
+ int rc = 0;
+
+ if (iface->state == state_dead)
+ return -1;
+
+ /* Prepare datas & select mode */
+ iface->cur_mode &= ~KW_I2C_MODE_MODE_MASK;
+ switch (size) {
+ case I2C_SMBUS_QUICK:
+ len = 0;
+ buffer = NULL;
+ iface->cur_mode |= KW_I2C_MODE_STANDARD;
+ break;
+ case I2C_SMBUS_BYTE:
+ len = 1;
+ buffer = &data->byte;
+ iface->cur_mode |= KW_I2C_MODE_STANDARD;
+ break;
+ case I2C_SMBUS_BYTE_DATA:
+ len = 1;
+ buffer = &data->byte;
+ iface->cur_mode |= KW_I2C_MODE_STANDARDSUB;
+ break;
+ case I2C_SMBUS_WORD_DATA:
+ len = 2;
+ cur_word = cpu_to_le16(data->word);
+ buffer = (u8 *)&cur_word;
+ iface->cur_mode |= KW_I2C_MODE_STANDARDSUB;
+ break;
+ case I2C_SMBUS_BLOCK_DATA:
+ len = data->block[0];
+ buffer = &data->block[1];
+ iface->cur_mode |= KW_I2C_MODE_STANDARDSUB;
+ break;
+ default:
+ return -1;
+ }
+
+ /* Original driver had this limitation */
+ if (len > 32)
+ len = 32;
+
+ down(&iface->sem);
+
+ DBG("chan: %d, addr: 0x%x, transfer len: %d, read: %d\n",
+ chan->chan_no, addr, len, read_write == I2C_SMBUS_READ);
+
+ iface->data = buffer;
+ iface->datalen = len;
+ iface->state = state_addr;
+ iface->result = 0;
+ iface->stopretry = 0;
+ iface->read_write = read_write;
+
+ /* Setup channel & clear pending irqs */
+ write_reg(reg_mode, iface->cur_mode | (chan->chan_no << 4));
+ write_reg(reg_isr, read_reg(reg_isr));
+ write_reg(reg_status, 0);
+
+ /* Set up address and r/w bit */
+ write_reg(reg_addr,
+ (addr << 1) | ((read_write == I2C_SMBUS_READ) ? 0x01 : 0x00));
+
+ /* Set up the sub address */
+ if ((iface->cur_mode & KW_I2C_MODE_MODE_MASK) == KW_I2C_MODE_STANDARDSUB
+ || (iface->cur_mode & KW_I2C_MODE_MODE_MASK) == KW_I2C_MODE_COMBINED)
+ write_reg(reg_subaddr, command);
+
+ /* Arm timeout */
+ iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
+ add_timer(&iface->timeout_timer);
+
+ /* Start sending address & enable interrupt*/
+ write_reg(reg_control, read_reg(reg_control) | KW_I2C_CTL_XADDR);
+ write_reg(reg_ier, KW_I2C_IRQ_MASK);
+
+#ifdef POLLED_MODE
+ DBG("using polled mode...\n");
+ /* State machine, to turn into an interrupt handler */
+ while(iface->state != state_idle) {
+ u8 isr = wait_interrupt(iface);
+ handle_interrupt(iface, isr);
+ }
+#else /* POLLED_MODE */
+ DBG("using interrupt mode...\n");
+ wait_for_completion(&iface->complete);
+#endif /* POLLED_MODE */
+
+ rc = iface->result;
+ DBG("transfer done, result: %d\n", rc);
+
+ if (rc == 0 && size == I2C_SMBUS_WORD_DATA && read_write == I2C_SMBUS_READ)
+ data->word = le16_to_cpu(cur_word);
+
+ /* Release sem */
+ up(&iface->sem);
+
+ return rc;
+}
+
+/*
+ * Generic i2c master transfer entrypoint
+ */
+static int
+keywest_xfer( struct i2c_adapter *adap,
+ struct i2c_msg msgs[],
+ int num)
+{
+ struct keywest_chan* chan = (struct keywest_chan*)adap->data;
+ struct keywest_iface* iface = chan->iface;
+ struct i2c_msg *pmsg;
+ int i, completed;
+ int rc = 0;
+
+ down(&iface->sem);
+
+ /* Set adapter to standard mode */
+ iface->cur_mode &= ~KW_I2C_MODE_MODE_MASK;
+ iface->cur_mode |= KW_I2C_MODE_STANDARD;
+
+ completed = 0;
+ for (i = 0; rc >= 0 && i < num;) {
+ u8 addr;
+
+ pmsg = &msgs[i++];
+ addr = pmsg->addr;
+ if (pmsg->flags & I2C_M_TEN) {
+ printk(KERN_ERR "i2c-keywest: 10 bits addr not supported !\n");
+ rc = -EINVAL;
+ break;
+ }
+ DBG("xfer: chan: %d, doing %s %d bytes to 0x%02x - %d of %d messages\n",
+ chan->chan_no,
+ pmsg->flags & I2C_M_RD ? "read" : "write",
+ pmsg->len, addr, i, num);
+
+ /* Setup channel & clear pending irqs */
+ write_reg(reg_mode, iface->cur_mode | (chan->chan_no << 4));
+ write_reg(reg_isr, read_reg(reg_isr));
+ write_reg(reg_status, 0);
+
+ iface->data = pmsg->buf;
+ iface->datalen = pmsg->len;
+ iface->state = state_addr;
+ iface->result = 0;
+ iface->stopretry = 0;
+ if (pmsg->flags & I2C_M_RD)
+ iface->read_write = I2C_SMBUS_READ;
+ else
+ iface->read_write = I2C_SMBUS_WRITE;
+
+ /* Set up address and r/w bit */
+ if (pmsg->flags & I2C_M_REV_DIR_ADDR)
+ addr ^= 1;
+ write_reg(reg_addr,
+ (addr << 1) |
+ ((iface->read_write == I2C_SMBUS_READ) ? 0x01 : 0x00));
+
+ /* Arm timeout */
+ iface->timeout_timer.expires = jiffies + POLL_TIMEOUT;
+ add_timer(&iface->timeout_timer);
+
+ /* Start sending address & enable interrupt*/
+ write_reg(reg_control, read_reg(reg_control) | KW_I2C_CTL_XADDR);
+ write_reg(reg_ier, KW_I2C_IRQ_MASK);
+
+#ifdef POLLED_MODE
+ DBG("using polled mode...\n");
+ /* State machine, to turn into an interrupt handler */
+ while(iface->state != state_idle) {
+ u8 isr = wait_interrupt(iface);
+ handle_interrupt(iface, isr);
+ }
+#else /* POLLED_MODE */88
+ DBG("using interrupt mode...\n");
+ wait_for_completion(&iface->complete);
+#endif /* POLLED_MODE */
+
+ rc = iface->result;
+ if (rc == 0)
+ completed++;
+ DBG("transfer done, result: %d\n", rc);
+ }
+
+ /* Release sem */
+ up(&iface->sem);
+
+ return completed;
+}
+
+static u32
+keywest_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 void
+keywest_inc(struct i2c_adapter *adapter)
+{
+ MOD_INC_USE_COUNT;
+}
+
+static void
+keywest_dec(struct i2c_adapter *adapter)
+{
+ MOD_DEC_USE_COUNT;
+}
+
+/* For now, we only handle combined mode (smbus) */
+static struct i2c_algorithm keywest_algorithm = {
+ name: "Keywest i2c",
+ id: I2C_ALGO_SMBUS,
+ smbus_xfer: keywest_smbus_xfer,
+ master_xfer: keywest_xfer,
+ functionality: keywest_func,
+};
+
+
+static int
+create_iface(struct device_node* np)
+{
+ unsigned long steps, *psteps, *prate;
+ unsigned bsteps, tsize, i, nchan, addroffset;
+ struct keywest_iface* iface;
+ int rc;
+
+ psteps = (unsigned long *)get_property(np, "AAPL,address-step", NULL);
+ steps = psteps ? (*psteps) : 0x10;
+
+ /* Hrm... maybe we can be smarter here */
+ for (bsteps = 0; (steps & 0x01) == 0; bsteps++)
+ steps >>= 1;
+
+ if (!strcmp(np->parent->name, "uni-n")) {
+ nchan = 2;
+ addroffset = 3;
+ } else {
+ addroffset = 0;
+ nchan = 1;
+ }
+
+ tsize = sizeof(struct keywest_iface) +
+ (sizeof(struct keywest_chan) + 4) * nchan;
+ iface = (struct keywest_iface *) kmalloc(tsize, GFP_KERNEL);
+ if (iface == NULL) {
+ printk(KERN_ERR "i2c-keywest: can't allocate inteface !\n");
+ return -ENOMEM;
+ }
+ memset(iface, 0, tsize);
+ init_MUTEX(&iface->sem);
+ spin_lock_init(&iface->lock);
+ init_completion(&iface->complete);
+ iface->bsteps = bsteps;
+ iface->chan_count = nchan;
+ iface->state = state_idle;
+ iface->irq = np->intrs[0].line;
+ iface->channels = (struct keywest_chan *)
+ (((unsigned long)(iface + 1) + 3UL) & ~3UL);
+ iface->base = (unsigned long)ioremap(np->addrs[0].address + addroffset,
+ np->addrs[0].size);
+ if (iface->base == 0) {
+ printk(KERN_ERR "i2c-keywest: can't map inteface !\n");
+ kfree(iface);
+ return -ENOMEM;
+ }
+
+ init_timer(&iface->timeout_timer);
+ iface->timeout_timer.function = keywest_timeout;
+ iface->timeout_timer.data = (unsigned long)iface;
+
+ /* Select interface rate */
+ iface->cur_mode = KW_I2C_MODE_100KHZ;
+ prate = (unsigned long *)get_property(np, "AAPL,i2c-rate", NULL);
+ if (prate) switch(*prate) {
+ case 100:
+ iface->cur_mode = KW_I2C_MODE_100KHZ;
+ break;
+ case 50:
+ iface->cur_mode = KW_I2C_MODE_50KHZ;
+ break;
+ case 25:
+ iface->cur_mode = KW_I2C_MODE_25KHZ;
+ break;
+ default:
+ printk(KERN_WARNING "i2c-keywest: unknown rate %ldKhz, using 100KHz\n",
+ *prate);
+ }
+
+ /* Select standard sub mode */
+ iface->cur_mode |= KW_I2C_MODE_STANDARDSUB;
+
+ /* Write mode */
+ write_reg(reg_mode, iface->cur_mode);
+
+ /* Switch interrupts off & clear them*/
+ write_reg(reg_ier, 0x00);
+ write_reg(reg_isr, KW_I2C_IRQ_MASK);
+
+#ifndef POLLED_MODE
+ /* Request chip interrupt */
+ rc = request_irq(iface->irq, keywest_irq, 0, "keywest i2c", iface);
+ if (rc) {
+ printk(KERN_ERR "i2c-keywest: can't get IRQ %d !\n", iface->irq);
+ iounmap((void *)iface->base);
+ kfree(iface);
+ return -ENODEV;
+ }
+#endif /* POLLED_MODE */
+
+ for (i=0; i<nchan; i++) {
+ struct keywest_chan* chan = &iface->channels[i];
+ u8 addr;
+
+ sprintf(chan->adapter.name, "%s %d", np->parent->name, i);
+ chan->iface = iface;
+ chan->chan_no = i;
+ chan->adapter.id = I2C_ALGO_SMBUS;
+ chan->adapter.algo = &keywest_algorithm;
+ chan->adapter.algo_data = NULL;
+ chan->adapter.inc_use = keywest_inc;
+ chan->adapter.dec_use = keywest_dec;
+ chan->adapter.client_register = NULL;
+ chan->adapter.client_unregister = NULL;
+ chan->adapter.data = chan;
+
+ rc = i2c_add_adapter(&chan->adapter);
+ if (rc) {
+ printk("i2c-keywest.c: Adapter %s registration failed\n",
+ chan->adapter.name);
+ chan->adapter.data = NULL;
+ }
+ if (probe) {
+ printk("Probe: ");
+ for (addr = 0x00; addr <= 0x7f; addr++) {
+ if (i2c_smbus_xfer(&chan->adapter,addr,
+ 0,0,0,I2C_SMBUS_QUICK,NULL) >= 0)
+ printk("%02x ", addr);
+ }
+ printk("\n");
+ }
+ }
+
+ printk(KERN_INFO "Found KeyWest i2c on \"%s\", %d channel%s, stepping: %d bits\n",
+ np->parent->name, nchan, nchan > 1 ? "s" : "", bsteps);
+
+ iface->next = ifaces;
+ ifaces = iface;
+ return 0;
+}
+
+static void
+dispose_iface(struct keywest_iface *iface)
+{
+ int i, rc;
+
+ ifaces = iface->next;
+
+ /* Make sure we stop all activity */
+ down(&iface->sem);
+#ifndef POLLED_MODE
+ spin_lock_irq(&iface->lock);
+ while (iface->state != state_idle) {
+ spin_unlock_irq(&iface->lock);
+ schedule();
+ spin_lock_irq(&iface->lock);
+ }
+#endif /* POLLED_MODE */
+ iface->state = state_dead;
+#ifndef POLLED_MODE
+ spin_unlock_irq(&iface->lock);
+ free_irq(iface->irq, iface);
+#endif /* POLLED_MODE */
+ up(&iface->sem);
+
+ /* Release all channels */
+ for (i=0; i<iface->chan_count; i++) {
+ struct keywest_chan* chan = &iface->channels[i];
+ if (!chan->adapter.data)
+ continue;
+ rc = i2c_del_adapter(&chan->adapter);
+ chan->adapter.data = NULL;
+ /* We aren't that prepared to deal with this... */
+ if (rc)
+ printk("i2c-keywest.c: i2c_del_adapter failed, that's bad !\n");
+ }
+ iounmap((void *)iface->base);
+ kfree(iface);
+}
+
+static int __init
+i2c_keywest_init(void)
+{
+ struct device_node *np;
+ int rc = -ENODEV;
+
+ np = find_compatible_devices("i2c", "keywest");
+ while (np != 0) {
+ if (np->n_addrs >= 1 && np->n_intrs >= 1)
+ rc = create_iface(np);
+ np = np->next;
+ }
+ if (ifaces)
+ rc = 0;
+ return rc;
+}
+
+static void __exit
+i2c_keywest_cleanup(void)
+{
+ while(ifaces)
+ dispose_iface(ifaces);
+}
+
+module_init(i2c_keywest_init);
+module_exit(i2c_keywest_cleanup);
FUNET's LINUX-ADM group, linux-adm@nic.funet.fi
TCL-scripts by Sam Shen (who was at: slshen@lbl.gov)