1 files changed, 456 insertions, 0 deletions

diff --git a/drivers/i2c/busses/i2c-powermac.c b/drivers/i2c/busses/i2c-powermac.c
new file mode 100644
index 000000000..3e38e1149
--- /dev/null
+++ b/drivers/i2c/busses/i2c-powermac.c
@@ -0,0 +1,456 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+    i2c Support for Apple SMU Controller
+
+    Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp.
+                       <benh@kernel.crashing.org>
+
+
+*/
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/i2c.h>
+#include <linux/device.h>
+#include <linux/platform_device.h>
+#include <linux/of_irq.h>
+#include <asm/prom.h>
+#include <asm/pmac_low_i2c.h>
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("I2C driver for Apple PowerMac");
+MODULE_LICENSE("GPL");
+
+/*
+ * SMBUS-type transfer entrypoint
+ */
+static s32 i2c_powermac_smbus_xfer(	struct i2c_adapter*	adap,
+					u16			addr,
+					unsigned short		flags,
+					char			read_write,
+					u8			command,
+					int			size,
+					union i2c_smbus_data*	data)
+{
+	struct pmac_i2c_bus	*bus = i2c_get_adapdata(adap);
+	int			rc = 0;
+	int			read = (read_write == I2C_SMBUS_READ);
+	int			addrdir = (addr << 1) | read;
+	int			mode, subsize, len;
+	u32			subaddr;
+	u8			*buf;
+	u8			local[2];
+
+	if (size == I2C_SMBUS_QUICK || size == I2C_SMBUS_BYTE) {
+		mode = pmac_i2c_mode_std;
+		subsize = 0;
+		subaddr = 0;
+	} else {
+		mode = read ? pmac_i2c_mode_combined : pmac_i2c_mode_stdsub;
+		subsize = 1;
+		subaddr = command;
+	}
+
+	switch (size) {
+        case I2C_SMBUS_QUICK:
+		buf = NULL;
+		len = 0;
+	    	break;
+        case I2C_SMBUS_BYTE:
+        case I2C_SMBUS_BYTE_DATA:
+		buf = &data->byte;
+		len = 1;
+	    	break;
+        case I2C_SMBUS_WORD_DATA:
+		if (!read) {
+			local[0] = data->word & 0xff;
+			local[1] = (data->word >> 8) & 0xff;
+		}
+		buf = local;
+		len = 2;
+	    	break;
+
+	/* Note that these are broken vs. the expected smbus API where
+	 * on reads, the length is actually returned from the function,
+	 * but I think the current API makes no sense and I don't want
+	 * any driver that I haven't verified for correctness to go
+	 * anywhere near a pmac i2c bus anyway ...
+	 *
+	 * I'm also not completely sure what kind of phases to do between
+	 * the actual command and the data (what I am _supposed_ to do that
+	 * is). For now, I assume writes are a single stream and reads have
+	 * a repeat start/addr phase (but not stop in between)
+	 */
+        case I2C_SMBUS_BLOCK_DATA:
+		buf = data->block;
+		len = data->block[0] + 1;
+		break;
+	case I2C_SMBUS_I2C_BLOCK_DATA:
+		buf = &data->block[1];
+		len = data->block[0];
+		break;
+
+        default:
+		return -EINVAL;
+	}
+
+	rc = pmac_i2c_open(bus, 0);
+	if (rc) {
+		dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
+		return rc;
+	}
+
+	rc = pmac_i2c_setmode(bus, mode);
+	if (rc) {
+		dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
+			mode, rc);
+		goto bail;
+	}
+
+	rc = pmac_i2c_xfer(bus, addrdir, subsize, subaddr, buf, len);
+	if (rc) {
+		if (rc == -ENXIO)
+			dev_dbg(&adap->dev,
+				"I2C transfer at 0x%02x failed, size %d, "
+				"err %d\n", addrdir >> 1, size, rc);
+		else
+			dev_err(&adap->dev,
+				"I2C transfer at 0x%02x failed, size %d, "
+				"err %d\n", addrdir >> 1, size, rc);
+		goto bail;
+	}
+
+	if (size == I2C_SMBUS_WORD_DATA && read) {
+		data->word = ((u16)local[1]) << 8;
+		data->word |= local[0];
+	}
+
+ bail:
+	pmac_i2c_close(bus);
+	return rc;
+}
+
+/*
+ * Generic i2c master transfer entrypoint. This driver only support single
+ * messages (for "lame i2c" transfers). Anything else should use the smbus
+ * entry point
+ */
+static int i2c_powermac_master_xfer(	struct i2c_adapter *adap,
+					struct i2c_msg *msgs,
+					int num)
+{
+	struct pmac_i2c_bus	*bus = i2c_get_adapdata(adap);
+	int			rc = 0;
+	int			addrdir;
+
+	if (msgs->flags & I2C_M_TEN)
+		return -EINVAL;
+	addrdir = i2c_8bit_addr_from_msg(msgs);
+
+	rc = pmac_i2c_open(bus, 0);
+	if (rc) {
+		dev_err(&adap->dev, "Failed to open I2C, err %d\n", rc);
+		return rc;
+	}
+	rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
+	if (rc) {
+		dev_err(&adap->dev, "Failed to set I2C mode %d, err %d\n",
+			pmac_i2c_mode_std, rc);
+		goto bail;
+	}
+	rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
+	if (rc < 0) {
+		if (rc == -ENXIO)
+			dev_dbg(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
+				addrdir & 1 ? "read from" : "write to",
+				addrdir >> 1, rc);
+		else
+			dev_err(&adap->dev, "I2C %s 0x%02x failed, err %d\n",
+				addrdir & 1 ? "read from" : "write to",
+				addrdir >> 1, rc);
+	}
+ bail:
+	pmac_i2c_close(bus);
+	return rc < 0 ? rc : 1;
+}
+
+static u32 i2c_powermac_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 | I2C_FUNC_I2C;
+}
+
+/* For now, we only handle smbus */
+static const struct i2c_algorithm i2c_powermac_algorithm = {
+	.smbus_xfer	= i2c_powermac_smbus_xfer,
+	.master_xfer	= i2c_powermac_master_xfer,
+	.functionality	= i2c_powermac_func,
+};
+
+static const struct i2c_adapter_quirks i2c_powermac_quirks = {
+	.max_num_msgs = 1,
+};
+
+static int i2c_powermac_remove(struct platform_device *dev)
+{
+	struct i2c_adapter	*adapter = platform_get_drvdata(dev);
+
+	i2c_del_adapter(adapter);
+	memset(adapter, 0, sizeof(*adapter));
+
+	return 0;
+}
+
+static u32 i2c_powermac_get_addr(struct i2c_adapter *adap,
+					   struct pmac_i2c_bus *bus,
+					   struct device_node *node)
+{
+	u32 prop;
+	int ret;
+
+	/* First check for valid "reg" */
+	ret = of_property_read_u32(node, "reg", &prop);
+	if (ret == 0)
+		return (prop & 0xff) >> 1;
+
+	/* Then check old-style "i2c-address" */
+	ret = of_property_read_u32(node, "i2c-address", &prop);
+	if (ret == 0)
+		return (prop & 0xff) >> 1;
+
+	/* Now handle some devices with missing "reg" properties */
+	if (of_node_name_eq(node, "cereal"))
+		return 0x60;
+	else if (of_node_name_eq(node, "deq"))
+		return 0x34;
+
+	dev_warn(&adap->dev, "No i2c address for %pOF\n", node);
+
+	return 0xffffffff;
+}
+
+static void i2c_powermac_create_one(struct i2c_adapter *adap,
+					      const char *type,
+					      u32 addr)
+{
+	struct i2c_board_info info = {};
+	struct i2c_client *newdev;
+
+	strncpy(info.type, type, sizeof(info.type));
+	info.addr = addr;
+	newdev = i2c_new_client_device(adap, &info);
+	if (IS_ERR(newdev))
+		dev_err(&adap->dev,
+			"i2c-powermac: Failure to register missing %s\n",
+			type);
+}
+
+static void i2c_powermac_add_missing(struct i2c_adapter *adap,
+					       struct pmac_i2c_bus *bus,
+					       bool found_onyx)
+{
+	struct device_node *busnode = pmac_i2c_get_bus_node(bus);
+	int rc;
+
+	/* Check for the onyx audio codec */
+#define ONYX_REG_CONTROL		67
+	if (of_device_is_compatible(busnode, "k2-i2c") && !found_onyx) {
+		union i2c_smbus_data data;
+
+		rc = i2c_smbus_xfer(adap, 0x46, 0, I2C_SMBUS_READ,
+				    ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
+				    &data);
+		if (rc >= 0)
+			i2c_powermac_create_one(adap, "MAC,pcm3052", 0x46);
+
+		rc = i2c_smbus_xfer(adap, 0x47, 0, I2C_SMBUS_READ,
+				    ONYX_REG_CONTROL, I2C_SMBUS_BYTE_DATA,
+				    &data);
+		if (rc >= 0)
+			i2c_powermac_create_one(adap, "MAC,pcm3052", 0x47);
+	}
+}
+
+static bool i2c_powermac_get_type(struct i2c_adapter *adap,
+					    struct device_node *node,
+					    u32 addr, char *type, int type_size)
+{
+	char tmp[16];
+
+	/*
+	 * Note: we do _NOT_ want the standard i2c drivers to match with any of
+	 * our powermac stuff unless they have been specifically modified to
+	 * handle it on a case by case basis. For example, for thermal control,
+	 * things like lm75 etc... shall match with their corresponding
+	 * windfarm drivers, _NOT_ the generic ones, so we force a prefix of
+	 * 'MAC', onto the modalias to make that happen
+	 */
+
+	/* First try proper modalias */
+	if (of_modalias_node(node, tmp, sizeof(tmp)) >= 0) {
+		snprintf(type, type_size, "MAC,%s", tmp);
+		return true;
+	}
+
+	/* Now look for known workarounds */
+	if (of_node_name_eq(node, "deq")) {
+		/* Apple uses address 0x34 for TAS3001 and 0x35 for TAS3004 */
+		if (addr == 0x34) {
+			snprintf(type, type_size, "MAC,tas3001");
+			return true;
+		} else if (addr == 0x35) {
+			snprintf(type, type_size, "MAC,tas3004");
+			return true;
+		}
+	}
+
+	dev_err(&adap->dev, "i2c-powermac: modalias failure on %pOF\n", node);
+	return false;
+}
+
+static void i2c_powermac_register_devices(struct i2c_adapter *adap,
+						    struct pmac_i2c_bus *bus)
+{
+	struct i2c_client *newdev;
+	struct device_node *node;
+	bool found_onyx = false;
+
+	/*
+	 * In some cases we end up with the via-pmu node itself, in this
+	 * case we skip this function completely as the device-tree will
+	 * not contain anything useful.
+	 */
+	if (of_node_name_eq(adap->dev.of_node, "via-pmu"))
+		return;
+
+	for_each_child_of_node(adap->dev.of_node, node) {
+		struct i2c_board_info info = {};
+		u32 addr;
+
+		/* Get address & channel */
+		addr = i2c_powermac_get_addr(adap, bus, node);
+		if (addr == 0xffffffff)
+			continue;
+
+		/* Multibus setup, check channel */
+		if (!pmac_i2c_match_adapter(node, adap))
+			continue;
+
+		dev_dbg(&adap->dev, "i2c-powermac: register %pOF\n", node);
+
+		/*
+		 * Keep track of some device existence to handle
+		 * workarounds later.
+		 */
+		if (of_device_is_compatible(node, "pcm3052"))
+			found_onyx = true;
+
+		/* Make up a modalias */
+		if (!i2c_powermac_get_type(adap, node, addr,
+					   info.type, sizeof(info.type))) {
+			continue;
+		}
+
+		/* Fill out the rest of the info structure */
+		info.addr = addr;
+		info.irq = irq_of_parse_and_map(node, 0);
+		info.of_node = of_node_get(node);
+
+		newdev = i2c_new_client_device(adap, &info);
+		if (IS_ERR(newdev)) {
+			dev_err(&adap->dev, "i2c-powermac: Failure to register"
+				" %pOF\n", node);
+			of_node_put(node);
+			/* We do not dispose of the interrupt mapping on
+			 * purpose. It's not necessary (interrupt cannot be
+			 * re-used) and somebody else might have grabbed it
+			 * via direct DT lookup so let's not bother
+			 */
+			continue;
+		}
+	}
+
+	/* Additional workarounds */
+	i2c_powermac_add_missing(adap, bus, found_onyx);
+}
+
+static int i2c_powermac_probe(struct platform_device *dev)
+{
+	struct pmac_i2c_bus *bus = dev_get_platdata(&dev->dev);
+	struct device_node *parent;
+	struct i2c_adapter *adapter;
+	int rc;
+
+	if (bus == NULL)
+		return -EINVAL;
+	adapter = pmac_i2c_get_adapter(bus);
+
+	/* Ok, now we need to make up a name for the interface that will
+	 * match what we used to do in the past, that is basically the
+	 * controller's parent device node for keywest. PMU didn't have a
+	 * naming convention and SMU has a different one
+	 */
+	switch(pmac_i2c_get_type(bus)) {
+	case pmac_i2c_bus_keywest:
+		parent = of_get_parent(pmac_i2c_get_controller(bus));
+		if (parent == NULL)
+			return -EINVAL;
+		snprintf(adapter->name, sizeof(adapter->name), "%pOFn %d",
+			 parent,
+			 pmac_i2c_get_channel(bus));
+		of_node_put(parent);
+		break;
+	case pmac_i2c_bus_pmu:
+		snprintf(adapter->name, sizeof(adapter->name), "pmu %d",
+			 pmac_i2c_get_channel(bus));
+		break;
+	case pmac_i2c_bus_smu:
+		/* This is not what we used to do but I'm fixing drivers at
+		 * the same time as this change
+		 */
+		snprintf(adapter->name, sizeof(adapter->name), "smu %d",
+			 pmac_i2c_get_channel(bus));
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	platform_set_drvdata(dev, adapter);
+	adapter->algo = &i2c_powermac_algorithm;
+	adapter->quirks = &i2c_powermac_quirks;
+	i2c_set_adapdata(adapter, bus);
+	adapter->dev.parent = &dev->dev;
+
+	/* Clear of_node to skip automatic registration of i2c child nodes */
+	adapter->dev.of_node = NULL;
+	rc = i2c_add_adapter(adapter);
+	if (rc) {
+		printk(KERN_ERR "i2c-powermac: Adapter %s registration "
+		       "failed\n", adapter->name);
+		memset(adapter, 0, sizeof(*adapter));
+		return rc;
+	}
+
+	printk(KERN_INFO "PowerMac i2c bus %s registered\n", adapter->name);
+
+	/* Use custom child registration due to Apple device-tree funkyness */
+	adapter->dev.of_node = dev->dev.of_node;
+	i2c_powermac_register_devices(adapter, bus);
+
+	return 0;
+}
+
+static struct platform_driver i2c_powermac_driver = {
+	.probe = i2c_powermac_probe,
+	.remove = i2c_powermac_remove,
+	.driver = {
+		.name = "i2c-powermac",
+		.bus = &platform_bus_type,
+	},
+};
+
+module_platform_driver(i2c_powermac_driver);
+
+MODULE_ALIAS("platform:i2c-powermac");