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-rw-r--r--drivers/i2c/busses/i2c-mpc.c437
1 files changed, 437 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-mpc.c b/drivers/i2c/busses/i2c-mpc.c
new file mode 100644
index 0000000..a9a45fc
--- /dev/null
+++ b/drivers/i2c/busses/i2c-mpc.c
@@ -0,0 +1,437 @@
+/*
+ * (C) Copyright 2003-2004
+ * Humboldt Solutions Ltd, adrian@humboldt.co.uk.
+
+ * This is a combined i2c adapter and algorithm driver for the
+ * MPC107/Tsi107 PowerPC northbridge and processors that include
+ * the same I2C unit (8240, 8245, 85xx).
+ *
+ * Release 0.8
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/of_platform.h>
+#include <linux/of_i2c.h>
+
+#include <asm/io.h>
+#include <linux/fsl_devices.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/delay.h>
+
+#define DRV_NAME "mpc-i2c"
+
+#define MPC_I2C_FDR 0x04
+#define MPC_I2C_CR 0x08
+#define MPC_I2C_SR 0x0c
+#define MPC_I2C_DR 0x10
+#define MPC_I2C_DFSRR 0x14
+
+#define CCR_MEN 0x80
+#define CCR_MIEN 0x40
+#define CCR_MSTA 0x20
+#define CCR_MTX 0x10
+#define CCR_TXAK 0x08
+#define CCR_RSTA 0x04
+
+#define CSR_MCF 0x80
+#define CSR_MAAS 0x40
+#define CSR_MBB 0x20
+#define CSR_MAL 0x10
+#define CSR_SRW 0x04
+#define CSR_MIF 0x02
+#define CSR_RXAK 0x01
+
+struct mpc_i2c {
+ void __iomem *base;
+ u32 interrupt;
+ wait_queue_head_t queue;
+ struct i2c_adapter adap;
+ int irq;
+ u32 flags;
+};
+
+static __inline__ void writeccr(struct mpc_i2c *i2c, u32 x)
+{
+ writeb(x, i2c->base + MPC_I2C_CR);
+}
+
+static irqreturn_t mpc_i2c_isr(int irq, void *dev_id)
+{
+ struct mpc_i2c *i2c = dev_id;
+ if (readb(i2c->base + MPC_I2C_SR) & CSR_MIF) {
+ /* Read again to allow register to stabilise */
+ i2c->interrupt = readb(i2c->base + MPC_I2C_SR);
+ writeb(0, i2c->base + MPC_I2C_SR);
+ wake_up_interruptible(&i2c->queue);
+ }
+ return IRQ_HANDLED;
+}
+
+/* Sometimes 9th clock pulse isn't generated, and slave doesn't release
+ * the bus, because it wants to send ACK.
+ * Following sequence of enabling/disabling and sending start/stop generates
+ * the pulse, so it's all OK.
+ */
+static void mpc_i2c_fixup(struct mpc_i2c *i2c)
+{
+ writeccr(i2c, 0);
+ udelay(30);
+ writeccr(i2c, CCR_MEN);
+ udelay(30);
+ writeccr(i2c, CCR_MSTA | CCR_MTX);
+ udelay(30);
+ writeccr(i2c, CCR_MSTA | CCR_MTX | CCR_MEN);
+ udelay(30);
+ writeccr(i2c, CCR_MEN);
+ udelay(30);
+}
+
+static int i2c_wait(struct mpc_i2c *i2c, unsigned timeout, int writing)
+{
+ unsigned long orig_jiffies = jiffies;
+ u32 x;
+ int result = 0;
+
+ if (i2c->irq == NO_IRQ)
+ {
+ while (!(readb(i2c->base + MPC_I2C_SR) & CSR_MIF)) {
+ schedule();
+ if (time_after(jiffies, orig_jiffies + timeout)) {
+ pr_debug("I2C: timeout\n");
+ writeccr(i2c, 0);
+ result = -EIO;
+ break;
+ }
+ }
+ x = readb(i2c->base + MPC_I2C_SR);
+ writeb(0, i2c->base + MPC_I2C_SR);
+ } else {
+ /* Interrupt mode */
+ result = wait_event_interruptible_timeout(i2c->queue,
+ (i2c->interrupt & CSR_MIF), timeout * HZ);
+
+ if (unlikely(result < 0)) {
+ pr_debug("I2C: wait interrupted\n");
+ writeccr(i2c, 0);
+ } else if (unlikely(!(i2c->interrupt & CSR_MIF))) {
+ pr_debug("I2C: wait timeout\n");
+ writeccr(i2c, 0);
+ result = -ETIMEDOUT;
+ }
+
+ x = i2c->interrupt;
+ i2c->interrupt = 0;
+ }
+
+ if (result < 0)
+ return result;
+
+ if (!(x & CSR_MCF)) {
+ pr_debug("I2C: unfinished\n");
+ return -EIO;
+ }
+
+ if (x & CSR_MAL) {
+ pr_debug("I2C: MAL\n");
+ return -EIO;
+ }
+
+ if (writing && (x & CSR_RXAK)) {
+ pr_debug("I2C: No RXAK\n");
+ /* generate stop */
+ writeccr(i2c, CCR_MEN);
+ return -EIO;
+ }
+ return 0;
+}
+
+static void mpc_i2c_setclock(struct mpc_i2c *i2c)
+{
+ /* Set clock and filters */
+ if (i2c->flags & FSL_I2C_DEV_SEPARATE_DFSRR) {
+ writeb(0x31, i2c->base + MPC_I2C_FDR);
+ writeb(0x10, i2c->base + MPC_I2C_DFSRR);
+ } else if (i2c->flags & FSL_I2C_DEV_CLOCK_5200)
+ writeb(0x3f, i2c->base + MPC_I2C_FDR);
+ else
+ writel(0x1031, i2c->base + MPC_I2C_FDR);
+}
+
+static void mpc_i2c_start(struct mpc_i2c *i2c)
+{
+ /* Clear arbitration */
+ writeb(0, i2c->base + MPC_I2C_SR);
+ /* Start with MEN */
+ writeccr(i2c, CCR_MEN);
+}
+
+static void mpc_i2c_stop(struct mpc_i2c *i2c)
+{
+ writeccr(i2c, CCR_MEN);
+}
+
+static int mpc_write(struct mpc_i2c *i2c, int target,
+ const u8 * data, int length, int restart)
+{
+ int i, result;
+ unsigned timeout = i2c->adap.timeout;
+ u32 flags = restart ? CCR_RSTA : 0;
+
+ /* Start with MEN */
+ if (!restart)
+ writeccr(i2c, CCR_MEN);
+ /* Start as master */
+ writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
+ /* Write target byte */
+ writeb((target << 1), i2c->base + MPC_I2C_DR);
+
+ result = i2c_wait(i2c, timeout, 1);
+ if (result < 0)
+ return result;
+
+ for (i = 0; i < length; i++) {
+ /* Write data byte */
+ writeb(data[i], i2c->base + MPC_I2C_DR);
+
+ result = i2c_wait(i2c, timeout, 1);
+ if (result < 0)
+ return result;
+ }
+
+ return 0;
+}
+
+static int mpc_read(struct mpc_i2c *i2c, int target,
+ u8 * data, int length, int restart)
+{
+ unsigned timeout = i2c->adap.timeout;
+ int i, result;
+ u32 flags = restart ? CCR_RSTA : 0;
+
+ /* Start with MEN */
+ if (!restart)
+ writeccr(i2c, CCR_MEN);
+ /* Switch to read - restart */
+ writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_MTX | flags);
+ /* Write target address byte - this time with the read flag set */
+ writeb((target << 1) | 1, i2c->base + MPC_I2C_DR);
+
+ result = i2c_wait(i2c, timeout, 1);
+ if (result < 0)
+ return result;
+
+ if (length) {
+ if (length == 1)
+ writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
+ else
+ writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA);
+ /* Dummy read */
+ readb(i2c->base + MPC_I2C_DR);
+ }
+
+ for (i = 0; i < length; i++) {
+ result = i2c_wait(i2c, timeout, 0);
+ if (result < 0)
+ return result;
+
+ /* Generate txack on next to last byte */
+ if (i == length - 2)
+ writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_MSTA | CCR_TXAK);
+ /* Generate stop on last byte */
+ if (i == length - 1)
+ writeccr(i2c, CCR_MIEN | CCR_MEN | CCR_TXAK);
+ data[i] = readb(i2c->base + MPC_I2C_DR);
+ }
+
+ return length;
+}
+
+static int mpc_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+ struct i2c_msg *pmsg;
+ int i;
+ int ret = 0;
+ unsigned long orig_jiffies = jiffies;
+ struct mpc_i2c *i2c = i2c_get_adapdata(adap);
+
+ mpc_i2c_start(i2c);
+
+ /* Allow bus up to 1s to become not busy */
+ while (readb(i2c->base + MPC_I2C_SR) & CSR_MBB) {
+ if (signal_pending(current)) {
+ pr_debug("I2C: Interrupted\n");
+ writeccr(i2c, 0);
+ return -EINTR;
+ }
+ if (time_after(jiffies, orig_jiffies + HZ)) {
+ pr_debug("I2C: timeout\n");
+ if (readb(i2c->base + MPC_I2C_SR) ==
+ (CSR_MCF | CSR_MBB | CSR_RXAK))
+ mpc_i2c_fixup(i2c);
+ return -EIO;
+ }
+ schedule();
+ }
+
+ for (i = 0; ret >= 0 && i < num; i++) {
+ pmsg = &msgs[i];
+ pr_debug("Doing %s %d bytes to 0x%02x - %d of %d messages\n",
+ pmsg->flags & I2C_M_RD ? "read" : "write",
+ pmsg->len, pmsg->addr, i + 1, num);
+ if (pmsg->flags & I2C_M_RD)
+ ret =
+ mpc_read(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
+ else
+ ret =
+ mpc_write(i2c, pmsg->addr, pmsg->buf, pmsg->len, i);
+ }
+ mpc_i2c_stop(i2c);
+ return (ret < 0) ? ret : num;
+}
+
+static u32 mpc_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
+}
+
+static const struct i2c_algorithm mpc_algo = {
+ .master_xfer = mpc_xfer,
+ .functionality = mpc_functionality,
+};
+
+static struct i2c_adapter mpc_ops = {
+ .owner = THIS_MODULE,
+ .name = "MPC adapter",
+ .id = I2C_HW_MPC107,
+ .algo = &mpc_algo,
+ .timeout = 1,
+};
+
+static int __devinit fsl_i2c_probe(struct of_device *op, const struct of_device_id *match)
+{
+ int result = 0;
+ struct mpc_i2c *i2c;
+
+ i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
+ if (!i2c)
+ return -ENOMEM;
+
+ if (of_get_property(op->node, "dfsrr", NULL))
+ i2c->flags |= FSL_I2C_DEV_SEPARATE_DFSRR;
+
+ if (of_device_is_compatible(op->node, "fsl,mpc5200-i2c") ||
+ of_device_is_compatible(op->node, "mpc5200-i2c"))
+ i2c->flags |= FSL_I2C_DEV_CLOCK_5200;
+
+ init_waitqueue_head(&i2c->queue);
+
+ i2c->base = of_iomap(op->node, 0);
+ if (!i2c->base) {
+ printk(KERN_ERR "i2c-mpc - failed to map controller\n");
+ result = -ENOMEM;
+ goto fail_map;
+ }
+
+ i2c->irq = irq_of_parse_and_map(op->node, 0);
+ if (i2c->irq != NO_IRQ) { /* i2c->irq = NO_IRQ implies polling */
+ result = request_irq(i2c->irq, mpc_i2c_isr,
+ IRQF_SHARED, "i2c-mpc", i2c);
+ if (result < 0) {
+ printk(KERN_ERR "i2c-mpc - failed to attach interrupt\n");
+ goto fail_request;
+ }
+ }
+
+ mpc_i2c_setclock(i2c);
+
+ dev_set_drvdata(&op->dev, i2c);
+
+ i2c->adap = mpc_ops;
+ i2c_set_adapdata(&i2c->adap, i2c);
+ i2c->adap.dev.parent = &op->dev;
+
+ result = i2c_add_adapter(&i2c->adap);
+ if (result < 0) {
+ printk(KERN_ERR "i2c-mpc - failed to add adapter\n");
+ goto fail_add;
+ }
+ of_register_i2c_devices(&i2c->adap, op->node);
+
+ return result;
+
+ fail_add:
+ dev_set_drvdata(&op->dev, NULL);
+ free_irq(i2c->irq, i2c);
+ fail_request:
+ irq_dispose_mapping(i2c->irq);
+ iounmap(i2c->base);
+ fail_map:
+ kfree(i2c);
+ return result;
+};
+
+static int __devexit fsl_i2c_remove(struct of_device *op)
+{
+ struct mpc_i2c *i2c = dev_get_drvdata(&op->dev);
+
+ i2c_del_adapter(&i2c->adap);
+ dev_set_drvdata(&op->dev, NULL);
+
+ if (i2c->irq != NO_IRQ)
+ free_irq(i2c->irq, i2c);
+
+ irq_dispose_mapping(i2c->irq);
+ iounmap(i2c->base);
+ kfree(i2c);
+ return 0;
+};
+
+static const struct of_device_id mpc_i2c_of_match[] = {
+ {.compatible = "fsl-i2c",},
+ {},
+};
+MODULE_DEVICE_TABLE(of, mpc_i2c_of_match);
+
+
+/* Structure for a device driver */
+static struct of_platform_driver mpc_i2c_driver = {
+ .match_table = mpc_i2c_of_match,
+ .probe = fsl_i2c_probe,
+ .remove = __devexit_p(fsl_i2c_remove),
+ .driver = {
+ .owner = THIS_MODULE,
+ .name = DRV_NAME,
+ },
+};
+
+static int __init fsl_i2c_init(void)
+{
+ int rv;
+
+ rv = of_register_platform_driver(&mpc_i2c_driver);
+ if (rv)
+ printk(KERN_ERR DRV_NAME
+ " of_register_platform_driver failed (%i)\n", rv);
+ return rv;
+}
+
+static void __exit fsl_i2c_exit(void)
+{
+ of_unregister_platform_driver(&mpc_i2c_driver);
+}
+
+module_init(fsl_i2c_init);
+module_exit(fsl_i2c_exit);
+
+MODULE_AUTHOR("Adrian Cox <adrian@humboldt.co.uk>");
+MODULE_DESCRIPTION
+ ("I2C-Bus adapter for MPC107 bridge and MPC824x/85xx/52xx processors");
+MODULE_LICENSE("GPL");
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