1 files changed, 425 insertions, 0 deletions
diff --git a/drivers/sbus/char/bbc_i2c.c b/drivers/sbus/char/bbc_i2c.c
new file mode 100644
index 000000000..537e55cd0
--- /dev/null
+++ b/drivers/sbus/char/bbc_i2c.c
@@ -0,0 +1,425 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/* bbc_i2c.c: I2C low-level driver for BBC device on UltraSPARC-III
+ *            platforms.
+ *
+ * Copyright (C) 2001, 2008 David S. Miller (davem@davemloft.net)
+ */
+
+#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/interrupt.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <asm/bbc.h>
+#include <asm/io.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.
+ */
+
+static void set_device_claimage(struct bbc_i2c_bus *bp, struct platform_device *op, int val)
+{
+	int i;
+
+	for (i = 0; i < NUM_CHILDREN; i++) {
+		if (bp->devs[i].device == op) {
+			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)
+
+struct platform_device *bbc_i2c_getdev(struct bbc_i2c_bus *bp, int index)
+{
+	struct platform_device *op = NULL;
+	int curidx = 0, i;
+
+	for (i = 0; i < NUM_CHILDREN; i++) {
+		if (!(op = bp->devs[i].device))
+			break;
+		if (curidx == index)
+			goto out;
+		op = NULL;
+		curidx++;
+	}
+
+out:
+	if (curidx == index)
+		return op;
+	return NULL;
+}
+
+struct bbc_i2c_client *bbc_i2c_attach(struct bbc_i2c_bus *bp, struct platform_device *op)
+{
+	struct bbc_i2c_client *client;
+	const u32 *reg;
+
+	client = kzalloc(sizeof(*client), GFP_KERNEL);
+	if (!client)
+		return NULL;
+	client->bp = bp;
+	client->op = op;
+
+	reg = of_get_property(op->dev.of_node, "reg", NULL);
+	if (!reg) {
+		kfree(client);
+		return NULL;
+	}
+
+	client->bus = reg[0];
+	client->address = reg[1];
+
+	claim_device(bp, op);
+
+	return client;
+}
+
+void bbc_i2c_detach(struct bbc_i2c_client *client)
+{
+	struct bbc_i2c_bus *bp = client->bp;
+	struct platform_device *op = client->op;
+
+	release_device(bp, op);
+	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) {
+		long val;
+
+		val = wait_event_interruptible_timeout(
+				bp->wq,
+				(((*status = readb(bp->i2c_control_regs + 0))
+				  & I2C_PCF_PIN) == 0),
+				msecs_to_jiffies(250));
+		if (val > 0) {
+			ret = 0;
+			break;
+		}
+	}
+	remove_wait_queue(&bp->wq, &wait);
+	bp->waiting = 0;
+
+	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) {
+		ret = bbc_i2c_writeb(client, *buf, off);
+		if (ret < 0)
+			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) {
+		ret = bbc_i2c_readb(client, buf, off);
+		if (ret < 0)
+			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 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_interruptible(&bp->wq);
+
+	return IRQ_HANDLED;
+}
+
+static void 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 struct bbc_i2c_bus * attach_one_i2c(struct platform_device *op, int index)
+{
+	struct bbc_i2c_bus *bp;
+	struct device_node *dp;
+	int entry;
+
+	bp = kzalloc(sizeof(*bp), GFP_KERNEL);
+	if (!bp)
+		return NULL;
+
+	INIT_LIST_HEAD(&bp->temps);
+	INIT_LIST_HEAD(&bp->fans);
+
+	bp->i2c_control_regs = of_ioremap(&op->resource[0], 0, 0x2, "bbc_i2c_regs");
+	if (!bp->i2c_control_regs)
+		goto fail;
+
+	if (op->num_resources == 2) {
+		bp->i2c_bussel_reg = of_ioremap(&op->resource[1], 0, 0x1, "bbc_i2c_bussel");
+		if (!bp->i2c_bussel_reg)
+			goto fail;
+	}
+
+	bp->waiting = 0;
+	init_waitqueue_head(&bp->wq);
+	if (request_irq(op->archdata.irqs[0], bbc_i2c_interrupt,
+			IRQF_SHARED, "bbc_i2c", bp))
+		goto fail;
+
+	bp->index = index;
+	bp->op = op;
+
+	spin_lock_init(&bp->lock);
+
+	entry = 0;
+	for (dp = op->dev.of_node->child;
+	     dp && entry < 8;
+	     dp = dp->sibling, entry++) {
+		struct platform_device *child_op;
+
+		child_op = of_find_device_by_node(dp);
+		bp->devs[entry].device = child_op;
+		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 bp;
+
+fail:
+	if (bp->i2c_bussel_reg)
+		of_iounmap(&op->resource[1], bp->i2c_bussel_reg, 1);
+	if (bp->i2c_control_regs)
+		of_iounmap(&op->resource[0], bp->i2c_control_regs, 2);
+	kfree(bp);
+	return NULL;
+}
+
+extern int bbc_envctrl_init(struct bbc_i2c_bus *bp);
+extern void bbc_envctrl_cleanup(struct bbc_i2c_bus *bp);
+
+static int bbc_i2c_probe(struct platform_device *op)
+{
+	struct bbc_i2c_bus *bp;
+	int err, index = 0;
+
+	bp = attach_one_i2c(op, index);
+	if (!bp)
+		return -EINVAL;
+
+	err = bbc_envctrl_init(bp);
+	if (err) {
+		free_irq(op->archdata.irqs[0], bp);
+		if (bp->i2c_bussel_reg)
+			of_iounmap(&op->resource[0], bp->i2c_bussel_reg, 1);
+		if (bp->i2c_control_regs)
+			of_iounmap(&op->resource[1], bp->i2c_control_regs, 2);
+		kfree(bp);
+	} else {
+		dev_set_drvdata(&op->dev, bp);
+	}
+
+	return err;
+}
+
+static int bbc_i2c_remove(struct platform_device *op)
+{
+	struct bbc_i2c_bus *bp = dev_get_drvdata(&op->dev);
+
+	bbc_envctrl_cleanup(bp);
+
+	free_irq(op->archdata.irqs[0], bp);
+
+	if (bp->i2c_bussel_reg)
+		of_iounmap(&op->resource[0], bp->i2c_bussel_reg, 1);
+	if (bp->i2c_control_regs)
+		of_iounmap(&op->resource[1], bp->i2c_control_regs, 2);
+
+	kfree(bp);
+
+	return 0;
+}
+
+static const struct of_device_id bbc_i2c_match[] = {
+	{
+		.name = "i2c",
+		.compatible = "SUNW,bbc-i2c",
+	},
+	{},
+};
+MODULE_DEVICE_TABLE(of, bbc_i2c_match);
+
+static struct platform_driver bbc_i2c_driver = {
+	.driver = {
+		.name = "bbc_i2c",
+		.of_match_table = bbc_i2c_match,
+	},
+	.probe		= bbc_i2c_probe,
+	.remove		= bbc_i2c_remove,
+};
+
+module_platform_driver(bbc_i2c_driver);
+
+MODULE_LICENSE("GPL");