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path: root/drivers/sbus/char/bbc_i2c.c
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Diffstat (limited to 'drivers/sbus/char/bbc_i2c.c')
-rw-r--r--drivers/sbus/char/bbc_i2c.c488
1 files changed, 488 insertions, 0 deletions
diff --git a/drivers/sbus/char/bbc_i2c.c b/drivers/sbus/char/bbc_i2c.c
new file mode 100644
index 0000000..1c8b612
--- /dev/null
+++ b/drivers/sbus/char/bbc_i2c.c
@@ -0,0 +1,488 @@
+/* $Id: bbc_i2c.c,v 1.2 2001/04/02 09:59:08 davem Exp $
+ * bbc_i2c.c: I2C low-level driver for BBC device on UltraSPARC-III
+ * platforms.
+ *
+ * Copyright (C) 2001 David S. Miller (davem@redhat.com)
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/delay.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <asm/oplib.h>
+#include <asm/ebus.h>
+#include <asm/spitfire.h>
+#include <asm/bbc.h>
+
+#include "bbc_i2c.h"
+
+/* Convert this driver to use i2c bus layer someday... */
+#define I2C_PCF_PIN 0x80
+#define I2C_PCF_ESO 0x40
+#define I2C_PCF_ES1 0x20
+#define I2C_PCF_ES2 0x10
+#define I2C_PCF_ENI 0x08
+#define I2C_PCF_STA 0x04
+#define I2C_PCF_STO 0x02
+#define I2C_PCF_ACK 0x01
+
+#define I2C_PCF_START (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_ENI | I2C_PCF_STA | I2C_PCF_ACK)
+#define I2C_PCF_STOP (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_STO | I2C_PCF_ACK)
+#define I2C_PCF_REPSTART ( I2C_PCF_ESO | I2C_PCF_STA | I2C_PCF_ACK)
+#define I2C_PCF_IDLE (I2C_PCF_PIN | I2C_PCF_ESO | I2C_PCF_ACK)
+
+#define I2C_PCF_INI 0x40 /* 1 if not initialized */
+#define I2C_PCF_STS 0x20
+#define I2C_PCF_BER 0x10
+#define I2C_PCF_AD0 0x08
+#define I2C_PCF_LRB 0x08
+#define I2C_PCF_AAS 0x04
+#define I2C_PCF_LAB 0x02
+#define I2C_PCF_BB 0x01
+
+/* The BBC devices have two I2C controllers. The first I2C controller
+ * connects mainly to configuration proms (NVRAM, cpu configuration,
+ * dimm types, etc.). Whereas the second I2C controller connects to
+ * environmental control devices such as fans and temperature sensors.
+ * The second controller also connects to the smartcard reader, if present.
+ */
+
+#define NUM_CHILDREN 8
+struct bbc_i2c_bus {
+ struct bbc_i2c_bus *next;
+ int index;
+ spinlock_t lock;
+ void __iomem *i2c_bussel_reg;
+ void __iomem *i2c_control_regs;
+ unsigned char own, clock;
+
+ wait_queue_head_t wq;
+ volatile int waiting;
+
+ struct linux_ebus_device *bus_edev;
+ struct {
+ struct linux_ebus_child *device;
+ int client_claimed;
+ } devs[NUM_CHILDREN];
+};
+
+static struct bbc_i2c_bus *all_bbc_i2c;
+
+struct bbc_i2c_client {
+ struct bbc_i2c_bus *bp;
+ struct linux_ebus_child *echild;
+ int bus;
+ int address;
+};
+
+static int find_device(struct bbc_i2c_bus *bp, struct linux_ebus_child *echild)
+{
+ int i;
+
+ for (i = 0; i < NUM_CHILDREN; i++) {
+ if (bp->devs[i].device == echild) {
+ if (bp->devs[i].client_claimed)
+ return 0;
+ return 1;
+ }
+ }
+ return 0;
+}
+
+static void set_device_claimage(struct bbc_i2c_bus *bp, struct linux_ebus_child *echild, int val)
+{
+ int i;
+
+ for (i = 0; i < NUM_CHILDREN; i++) {
+ if (bp->devs[i].device == echild) {
+ bp->devs[i].client_claimed = val;
+ return;
+ }
+ }
+}
+
+#define claim_device(BP,ECHILD) set_device_claimage(BP,ECHILD,1)
+#define release_device(BP,ECHILD) set_device_claimage(BP,ECHILD,0)
+
+static struct bbc_i2c_bus *find_bus_for_device(struct linux_ebus_child *echild)
+{
+ struct bbc_i2c_bus *bp = all_bbc_i2c;
+
+ while (bp != NULL) {
+ if (find_device(bp, echild) != 0)
+ break;
+ bp = bp->next;
+ }
+
+ return bp;
+}
+
+struct linux_ebus_child *bbc_i2c_getdev(int index)
+{
+ struct bbc_i2c_bus *bp = all_bbc_i2c;
+ struct linux_ebus_child *echild = NULL;
+ int curidx = 0;
+
+ while (bp != NULL) {
+ struct bbc_i2c_bus *next = bp->next;
+ int i;
+
+ for (i = 0; i < NUM_CHILDREN; i++) {
+ if (!(echild = bp->devs[i].device))
+ break;
+ if (curidx == index)
+ goto out;
+ echild = NULL;
+ curidx++;
+ }
+ bp = next;
+ }
+out:
+ if (curidx == index)
+ return echild;
+ return NULL;
+}
+
+struct bbc_i2c_client *bbc_i2c_attach(struct linux_ebus_child *echild)
+{
+ struct bbc_i2c_bus *bp = find_bus_for_device(echild);
+ struct bbc_i2c_client *client;
+
+ if (!bp)
+ return NULL;
+ client = kmalloc(sizeof(*client), GFP_KERNEL);
+ if (!client)
+ return NULL;
+ memset(client, 0, sizeof(*client));
+ client->bp = bp;
+ client->echild = echild;
+ client->bus = echild->resource[0].start;
+ client->address = echild->resource[1].start;
+
+ claim_device(bp, echild);
+
+ return client;
+}
+
+void bbc_i2c_detach(struct bbc_i2c_client *client)
+{
+ struct bbc_i2c_bus *bp = client->bp;
+ struct linux_ebus_child *echild = client->echild;
+
+ release_device(bp, echild);
+ kfree(client);
+}
+
+static int wait_for_pin(struct bbc_i2c_bus *bp, u8 *status)
+{
+ DECLARE_WAITQUEUE(wait, current);
+ int limit = 32;
+ int ret = 1;
+
+ bp->waiting = 1;
+ add_wait_queue(&bp->wq, &wait);
+ while (limit-- > 0) {
+ u8 val;
+
+ set_current_state(TASK_INTERRUPTIBLE);
+ *status = val = readb(bp->i2c_control_regs + 0);
+ if ((val & I2C_PCF_PIN) == 0) {
+ ret = 0;
+ break;
+ }
+ msleep_interruptible(250);
+ }
+ remove_wait_queue(&bp->wq, &wait);
+ bp->waiting = 0;
+ current->state = TASK_RUNNING;
+
+ return ret;
+}
+
+int bbc_i2c_writeb(struct bbc_i2c_client *client, unsigned char val, int off)
+{
+ struct bbc_i2c_bus *bp = client->bp;
+ int address = client->address;
+ u8 status;
+ int ret = -1;
+
+ if (bp->i2c_bussel_reg != NULL)
+ writeb(client->bus, bp->i2c_bussel_reg);
+
+ writeb(address, bp->i2c_control_regs + 0x1);
+ writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
+ if (wait_for_pin(bp, &status))
+ goto out;
+
+ writeb(off, bp->i2c_control_regs + 0x1);
+ if (wait_for_pin(bp, &status) ||
+ (status & I2C_PCF_LRB) != 0)
+ goto out;
+
+ writeb(val, bp->i2c_control_regs + 0x1);
+ if (wait_for_pin(bp, &status))
+ goto out;
+
+ ret = 0;
+
+out:
+ writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
+ return ret;
+}
+
+int bbc_i2c_readb(struct bbc_i2c_client *client, unsigned char *byte, int off)
+{
+ struct bbc_i2c_bus *bp = client->bp;
+ unsigned char address = client->address, status;
+ int ret = -1;
+
+ if (bp->i2c_bussel_reg != NULL)
+ writeb(client->bus, bp->i2c_bussel_reg);
+
+ writeb(address, bp->i2c_control_regs + 0x1);
+ writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
+ if (wait_for_pin(bp, &status))
+ goto out;
+
+ writeb(off, bp->i2c_control_regs + 0x1);
+ if (wait_for_pin(bp, &status) ||
+ (status & I2C_PCF_LRB) != 0)
+ goto out;
+
+ writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
+
+ address |= 0x1; /* READ */
+
+ writeb(address, bp->i2c_control_regs + 0x1);
+ writeb(I2C_PCF_START, bp->i2c_control_regs + 0x0);
+ if (wait_for_pin(bp, &status))
+ goto out;
+
+ /* Set PIN back to one so the device sends the first
+ * byte.
+ */
+ (void) readb(bp->i2c_control_regs + 0x1);
+ if (wait_for_pin(bp, &status))
+ goto out;
+
+ writeb(I2C_PCF_ESO | I2C_PCF_ENI, bp->i2c_control_regs + 0x0);
+ *byte = readb(bp->i2c_control_regs + 0x1);
+ if (wait_for_pin(bp, &status))
+ goto out;
+
+ ret = 0;
+
+out:
+ writeb(I2C_PCF_STOP, bp->i2c_control_regs + 0x0);
+ (void) readb(bp->i2c_control_regs + 0x1);
+
+ return ret;
+}
+
+int bbc_i2c_write_buf(struct bbc_i2c_client *client,
+ char *buf, int len, int off)
+{
+ int ret = 0;
+
+ while (len > 0) {
+ int err = bbc_i2c_writeb(client, *buf, off);
+
+ if (err < 0) {
+ ret = err;
+ break;
+ }
+
+ len--;
+ buf++;
+ off++;
+ }
+ return ret;
+}
+
+int bbc_i2c_read_buf(struct bbc_i2c_client *client,
+ char *buf, int len, int off)
+{
+ int ret = 0;
+
+ while (len > 0) {
+ int err = bbc_i2c_readb(client, buf, off);
+ if (err < 0) {
+ ret = err;
+ break;
+ }
+ len--;
+ buf++;
+ off++;
+ }
+
+ return ret;
+}
+
+EXPORT_SYMBOL(bbc_i2c_getdev);
+EXPORT_SYMBOL(bbc_i2c_attach);
+EXPORT_SYMBOL(bbc_i2c_detach);
+EXPORT_SYMBOL(bbc_i2c_writeb);
+EXPORT_SYMBOL(bbc_i2c_readb);
+EXPORT_SYMBOL(bbc_i2c_write_buf);
+EXPORT_SYMBOL(bbc_i2c_read_buf);
+
+static irqreturn_t bbc_i2c_interrupt(int irq, void *dev_id, struct pt_regs *regs)
+{
+ struct bbc_i2c_bus *bp = dev_id;
+
+ /* PIN going from set to clear is the only event which
+ * makes the i2c assert an interrupt.
+ */
+ if (bp->waiting &&
+ !(readb(bp->i2c_control_regs + 0x0) & I2C_PCF_PIN))
+ wake_up(&bp->wq);
+
+ return IRQ_HANDLED;
+}
+
+static void __init reset_one_i2c(struct bbc_i2c_bus *bp)
+{
+ writeb(I2C_PCF_PIN, bp->i2c_control_regs + 0x0);
+ writeb(bp->own, bp->i2c_control_regs + 0x1);
+ writeb(I2C_PCF_PIN | I2C_PCF_ES1, bp->i2c_control_regs + 0x0);
+ writeb(bp->clock, bp->i2c_control_regs + 0x1);
+ writeb(I2C_PCF_IDLE, bp->i2c_control_regs + 0x0);
+}
+
+static int __init attach_one_i2c(struct linux_ebus_device *edev, int index)
+{
+ struct bbc_i2c_bus *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
+ struct linux_ebus_child *echild;
+ int entry;
+
+ if (!bp)
+ return -ENOMEM;
+ memset(bp, 0, sizeof(*bp));
+
+ bp->i2c_control_regs = ioremap(edev->resource[0].start, 0x2);
+ if (!bp->i2c_control_regs)
+ goto fail;
+
+ if (edev->num_addrs == 2) {
+ bp->i2c_bussel_reg = ioremap(edev->resource[1].start, 0x1);
+ if (!bp->i2c_bussel_reg)
+ goto fail;
+ }
+
+ bp->waiting = 0;
+ init_waitqueue_head(&bp->wq);
+ if (request_irq(edev->irqs[0], bbc_i2c_interrupt,
+ SA_SHIRQ, "bbc_i2c", bp))
+ goto fail;
+
+ bp->index = index;
+ bp->bus_edev = edev;
+
+ spin_lock_init(&bp->lock);
+ bp->next = all_bbc_i2c;
+ all_bbc_i2c = bp;
+
+ entry = 0;
+ for (echild = edev->children;
+ echild && entry < 8;
+ echild = echild->next, entry++) {
+ bp->devs[entry].device = echild;
+ bp->devs[entry].client_claimed = 0;
+ }
+
+ writeb(I2C_PCF_PIN, bp->i2c_control_regs + 0x0);
+ bp->own = readb(bp->i2c_control_regs + 0x01);
+ writeb(I2C_PCF_PIN | I2C_PCF_ES1, bp->i2c_control_regs + 0x0);
+ bp->clock = readb(bp->i2c_control_regs + 0x01);
+
+ printk(KERN_INFO "i2c-%d: Regs at %p, %d devices, own %02x, clock %02x.\n",
+ bp->index, bp->i2c_control_regs, entry, bp->own, bp->clock);
+
+ reset_one_i2c(bp);
+
+ return 0;
+
+fail:
+ if (bp->i2c_bussel_reg)
+ iounmap(bp->i2c_bussel_reg);
+ if (bp->i2c_control_regs)
+ iounmap(bp->i2c_control_regs);
+ kfree(bp);
+ return -EINVAL;
+}
+
+static int __init bbc_present(void)
+{
+ struct linux_ebus *ebus = NULL;
+ struct linux_ebus_device *edev = NULL;
+
+ for_each_ebus(ebus) {
+ for_each_ebusdev(edev, ebus) {
+ if (!strcmp(edev->prom_name, "bbc"))
+ return 1;
+ }
+ }
+ return 0;
+}
+
+extern int bbc_envctrl_init(void);
+extern void bbc_envctrl_cleanup(void);
+static void bbc_i2c_cleanup(void);
+
+static int __init bbc_i2c_init(void)
+{
+ struct linux_ebus *ebus = NULL;
+ struct linux_ebus_device *edev = NULL;
+ int err, index = 0;
+
+ if (tlb_type != cheetah || !bbc_present())
+ return -ENODEV;
+
+ for_each_ebus(ebus) {
+ for_each_ebusdev(edev, ebus) {
+ if (!strcmp(edev->prom_name, "i2c")) {
+ if (!attach_one_i2c(edev, index))
+ index++;
+ }
+ }
+ }
+
+ if (!index)
+ return -ENODEV;
+
+ err = bbc_envctrl_init();
+ if (err)
+ bbc_i2c_cleanup();
+ return err;
+}
+
+static void bbc_i2c_cleanup(void)
+{
+ struct bbc_i2c_bus *bp = all_bbc_i2c;
+
+ bbc_envctrl_cleanup();
+
+ while (bp != NULL) {
+ struct bbc_i2c_bus *next = bp->next;
+
+ free_irq(bp->bus_edev->irqs[0], bp);
+
+ if (bp->i2c_bussel_reg)
+ iounmap(bp->i2c_bussel_reg);
+ if (bp->i2c_control_regs)
+ iounmap(bp->i2c_control_regs);
+
+ kfree(bp);
+
+ bp = next;
+ }
+ all_bbc_i2c = NULL;
+}
+
+module_init(bbc_i2c_init);
+module_exit(bbc_i2c_cleanup);
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