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path: root/drivers/i2c/busses/i2c-powermac.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-powermac.c')
-rw-r--r--drivers/i2c/busses/i2c-powermac.c468
1 files changed, 468 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..6abcf696e
--- /dev/null
+++ b/drivers/i2c/busses/i2c-powermac.c
@@ -0,0 +1,468 @@
+/*
+ i2c Support for Apple SMU Controller
+
+ Copyright (c) 2005 Benjamin Herrenschmidt, IBM Corp.
+ <benh@kernel.crashing.org>
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+*/
+
+#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 read;
+ int addrdir;
+
+ if (msgs->flags & I2C_M_TEN)
+ return -EINVAL;
+ read = (msgs->flags & I2C_M_RD) != 0;
+ addrdir = (msgs->addr << 1) | read;
+
+ 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 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)
+{
+ const __be32 *prop;
+ int len;
+
+ /* First check for valid "reg" */
+ prop = of_get_property(node, "reg", &len);
+ if (prop && (len >= sizeof(int)))
+ return (be32_to_cpup(prop) & 0xff) >> 1;
+
+ /* Then check old-style "i2c-address" */
+ prop = of_get_property(node, "i2c-address", &len);
+ if (prop && (len >= sizeof(int)))
+ return (be32_to_cpup(prop) & 0xff) >> 1;
+
+ /* Now handle some devices with missing "reg" properties */
+ if (!strcmp(node->name, "cereal"))
+ return 0x60;
+ else if (!strcmp(node->name, "deq"))
+ return 0x34;
+
+ dev_warn(&adap->dev, "No i2c address for %s\n", node->full_name);
+
+ 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_device(adap, &info);
+ if (!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 to _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 AAPL, 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 (!strcmp(node->name, "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 %s\n", node->full_name);
+ 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 = 0;
+
+ /*
+ * 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 (!strcmp(adap->dev.of_node->name, "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 %s\n",
+ node->full_name);
+
+ /*
+ * 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_device(adap, &info);
+ if (!newdev) {
+ dev_err(&adap->dev, "i2c-powermac: Failure to register"
+ " %s\n", node->full_name);
+ 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 = NULL;
+ struct i2c_adapter *adapter;
+ const char *basename;
+ 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;
+ basename = parent->name;
+ break;
+ case pmac_i2c_bus_pmu:
+ basename = "pmu";
+ 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
+ */
+ basename = "smu";
+ break;
+ default:
+ return -EINVAL;
+ }
+ snprintf(adapter->name, sizeof(adapter->name), "%s %d", basename,
+ pmac_i2c_get_channel(bus));
+ of_node_put(parent);
+
+ 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");
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-16 12:15:29 +0000