i2c: adds support for i2c bus on 8xx

Using the port of 2.4 code from Vitaly Bordug <[email protected]> and the actual algorithm used by the i2c driver of the DBox code on cvs.tuxboc.org from Tmbinc, Gillem ([email protected]). Renamed i2c-algo-8xx.c to i2c-algo-cpm.c and i2c-rpx.c to i2c-8xx.c. Added original i2c-rpx.c as i2c-8xx-ppc.c for pre-OF (arch ppc) devices.

arch/powerpc/platforms/8xx/mpc885ads_setup.c +0 -0

index 2cf1b6a..350018b 100644

arch/powerpc/platforms/8xx/mpc885ads_setup.c +4 -0

+static const char *i2c_regs = "regs";
+static const char *i2c_pram = "pram";
+static const char *i2c_irq = "interrupt";
+

drivers/i2c/algos/Kconfig +0 -0

index 014dfa5..7a8200e 100644

drivers/i2c/algos/Kconfig +15 -0

+static irqreturn_t cpm_iic_interrupt(int irq, void *dev_id)
+{
+	struct i2c_adapter *adap;
+	struct i2c_algo_cpm_data *cpm;
+	i2c8xx_t *i2c;
+	int i;
+
+	adap = (struct i2c_adapter *) dev_id;
+	cpm = adap->algo_data;
+	i2c = cpm->i2c;
+
+	/* Clear interrupt.
+	 */
+	i = in_8(&i2c->i2c_i2cer);
+	out_8(&i2c->i2c_i2cer, i);

drivers/i2c/algos/Kconfig +7 -0

+	ret = 0;
+	init_waitqueue_head(&cpm->iic_wait);
+	mutex_init(&cpm->iic_mutex);
+	/* Initialize the parameter ram.
+	 * We need to make sure many things are initialized to zero,
+	 * especially in the case of a microcode patch.
+	 */

drivers/i2c/algos/Kconfig +17 -0

+	out_8(&i2c->i2c_i2mod, 0x00);
+	out_8(&i2c->i2c_i2com, 0x01);	/* Master mode */
+
+	/* Disable interrupts.
+	 */
+	out_8(&i2c->i2c_i2cmr, 0);
+	out_8(&i2c->i2c_i2cer, 0xff);
+
+	/* Allocate TX and RX buffers */
+	for (i = 0; i < CPM_MAXBD; i++) {
+		cpm->rxbuf[i] = (unsigned char *)dma_alloc_coherent(
+			NULL, CPM_MAX_READ + 1, &cpm->rxdma[i], GFP_KERNEL);
+		if (!cpm->rxbuf[i]) {
+			ret = -ENOMEM;
+			goto out;
+		}
+		cpm->txbuf[i] = (unsigned char *)dma_alloc_coherent(

drivers/i2c/algos/Kconfig +5 -0

+static void cpm_parse_message(struct i2c_adapter *adap, struct i2c_msg *pmsg,
+	int num, int tx, int rx)
+{
+	cbd_t *tbdf, *rbdf;
+	u_char addr;

drivers/i2c/algos/Kconfig +10 -0

+static int cpm_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)
+{
+	struct i2c_algo_cpm_data *cpm = adap->algo_data;
+	i2c8xx_t *i2c = cpm->i2c;
+	iic_t *iip = cpm->iip;
+	struct i2c_msg *pmsg, *rmsg;
+	int ret, i;
+	int tptr;
+	int rptr;
+	cbd_t *tbdf, *rbdf;

drivers/i2c/algos/Kconfig +4 -0

+	while (tptr < num) {
+		/* Check for outstanding messages */
+		dev_dbg(&adap->dev, "test ready.\n");
+		if (!(tbdf[tptr].cbd_sc & BD_SC_READY)) {

drivers/i2c/busses/i2c-8xx.c new file +4 -0

new file mode 100644
index 0000000..c38b52e
@@ -0,0 +1,170 @@
+/*
+ * Embedded Planet RPX Lite MPC8xx CPM I2C interface.
+ * Copyright (c) 1999 Dan Malek ([email protected]).
+ *

drivers/i2c/busses/i2c-8xx.c new file +13 -0

+#include <linux/of_platform.h>
+#include <asm/mpc8xx.h>
+#include <asm/commproc.h>
+#include <asm/fs_pd.h>
+
+
+struct m8xx_i2c {
+	char *base;
+	struct of_device *ofdev;
+	struct i2c_adapter adap;
+	struct i2c_algo_cpm_data *algo_8xx;
+};
+

drivers/i2c/busses/i2c-8xx.c new file +11 -0

+	data->irq = irq_of_parse_and_map(np, 0);
+	if (data->irq < 0)
+		return -EINVAL;
+
+	if (of_address_to_resource(np, 1, &r))
+		return -EINVAL;
+
+	data->iip = ioremap(r.start, r.end - r.start + 1);
+	if (data->iip == NULL)
+		return -EINVAL;
+

drivers/i2c/busses/i2c-8xx.c new file +45 -0

+	if (!data->dp_addr)
+		return -ENOMEM;
+
+	return 0;
+}
+
+static int i2c_8xx_probe(struct of_device *ofdev,
+			 const struct of_device_id *match)
+{
+	int result;
+	struct m8xx_i2c *i2c;
+
+	i2c = kzalloc(sizeof(*i2c), GFP_KERNEL);
+	if (!i2c)
+		return -ENOMEM;
+
+	i2c->ofdev = ofdev;
+	i2c->algo_8xx = &m8xx_data;
+
+	m8xx_iic_init(i2c);
+
+	dev_set_drvdata(&ofdev->dev, i2c);
+
+	i2c->adap = m8xx_ops;
+	i2c_set_adapdata(&i2c->adap, i2c);
+	i2c->adap.dev.parent = &ofdev->dev;
+
+	result = i2c_cpm_add_bus(&i2c->adap);
+	if (result < 0) {
+		printk(KERN_ERR "i2c-8xx: Unable to register with I2C\n");
+		kfree(i2c);
+	}
+
+	return result;
+}
+
+static int i2c_8xx_remove(struct of_device *ofdev)
+{
+	struct m8xx_i2c *i2c = dev_get_drvdata(&ofdev->dev);
+
+	i2c_cpm_del_bus(&i2c->adap);
+	dev_set_drvdata(&ofdev->dev, NULL);
+
+	kfree(i2c);
+	return 0;

Do we really need to be adding features for arch/ppc at this point? It'll be going away in June. arch/ppc-specific things outside of arch/ppc itself will also be more likely to be missed in the removal.

Also, please post inline rather than as an attachment; attachments are harder to quote in a reply.

Quoted 6 lines

arch/powerpc/boot/dts/mpc885ads.dts +0 -0

index 8848e63..a526c02 100644
@@ -213,6 +213,15 @@
 				fsl,cpm-command = <0080>;

arch/powerpc/boot/dts/mpc885ads.dts line 227

Quoted 6 lines

arch/powerpc/boot/dts/mpc885ads.dts +3 -0

 				linux,network-index = <2>;
 			};
+
+			i2c@860 {
+				device_type = "i2c";
 

No device_type.

Should be fsl,cpm-i2c. Is cpm2 i2c the same? If not, it should be fsl,cpm1-i2c. It's probably best to specify it anyway, along with fsl,mpc885-i2c.

arch/powerpc/boot/dts/mpc885ads.dts line 225

Quoted 6 lines

arch/powerpc/boot/dts/mpc885ads.dts +5 -0

+#ifdef CONFIG_I2C_8XX
+	setbits32(&mpc8xx_immr->im_cpm.cp_pbpar, 0x00000030);
+	setbits32(&mpc8xx_immr->im_cpm.cp_pbdir, 0x00000030);
+	setbits16(&mpc8xx_immr->im_cpm.cp_pbodr, 0x0030);
+#endif
 

Please add this to mpc885ads_pins, rather than poking the registers directly. The relevant lines are:

	{CPM_PORTB, 26, CPM_PIN_OUTPUT},
	{CPM_PORTB, 27, CPM_PIN_OUTPUT},

arch/powerpc/boot/dts/mpc885ads.dts

Quoted 4 lines

arch/powerpc/boot/dts/mpc885ads.dts +3 -0

+	/* Select an arbitrary address.  Just make sure it is unique.
+	 */
+	out_8(&i2c->i2c_i2add, 0xfe);

It's a 7-bit address... and are you sure that 0x7e is unique? Does this driver even support slave operation?

Why is an 8xx driver matching all i2c cpm (i.e. what about cpm2)?

Quoted 6 lines

Quoted 6 lines

arch/powerpc/boot/dts/mpc885ads.dts +0 -0

index 8848e63..a526c02 100644
@@ -213,6 +213,15 @@
                 fsl,cpm-command = <0080>;

Quoted 9 lines

arch/powerpc/boot/dts/mpc885ads.dts line 227

Quoted 6 lines

arch/powerpc/boot/dts/mpc885ads.dts +3 -0

                 linux,network-index = <2>;
             };
+
+            i2c@860 {
+                device_type = "i2c";
 

No device_type.

Why? Documentation/powerpc/booting-without-of.txt says for I2C interfaces device_type is required and should be "i2c". Is this no longer true?

Quoted 3 lines

Should be fsl,cpm-i2c. Is cpm2 i2c the same? If not, it should be fsl,cpm1-i2c. It's probably best to specify it anyway, along with fsl,mpc885-i2c.

CPM2 i2c seems to be the same. However, i have no way to test this.

I noticed cpm1_set_pin32, but this function don't seem to set the odr register. Will this be added? Then it would be:

{CPM_PORTB, 26, CPM_PIN_OUTPUT | CPM_PIN_OPENDRAIN}, {CPM_PORTB, 27, CPM_PIN_OUTPUT | CPM_PIN_OPENDRAIN},

Quoted 2 lines

It's a 7-bit address... and are you sure that 0x7e is unique? Does this driver even support slave operation?

It's in fact 0x7F << 1.

The same value is used in the 2.4 driver and
in u-boot, as well.

Slave operation is not supported.

Quoted 1 line

Why is an 8xx driver matching all i2c cpm (i.e. what about cpm2)?

With the suggested change to use fsl,cpm-command, the driver should be able to use both cpm1 and cpm2. The operation and structs for i2c are identical. The only difference might be the hack^wsupport for relocation.

Quoted 8 lines

drivers/i2c/algos/i2c-algo-cpm.c line 154

Quoted 4 lines

drivers/i2c/algos/i2c-algo-cpm.c new file +3 -0

+	/* Select an arbitrary address.  Just make sure it is unique.
+	 */
+	out_8(&i2c->i2c_i2add, 0xfe);

It's a 7-bit address... and are you sure that 0x7e is unique? Does this driver even support slave operation?

It's in fact 0x7F << 1. The same value is used in the 2.4 driver and in u-boot, as well. Slave operation is not supported.

Quoted 7 lines

Quoted 7 lines

drivers/i2c/algos/i2c-algo-cpm.c line 154

Quoted 4 lines

drivers/i2c/algos/i2c-algo-cpm.c new file +3 -0

+	/* Select an arbitrary address.  Just make sure it is unique.
+	 */
+	out_8(&i2c->i2c_i2add, 0xfe);

It's a 7-bit address... and are you sure that 0x7e is unique? Does this driver even support slave operation?

Quoted 2 lines

It's in fact 0x7F << 1. The same value is used in the 2.4 driver and in u-boot, as well. Slave operation is not supported.

I'm not sure what exactly you are doing here, but 0x7f isn't a valid 7-bit I2C address.

From the MPC-823 documentation: