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Diffstat (limited to 'drivers/i2c/busses/i2c-powermac.c')
-rw-r--r--drivers/i2c/busses/i2c-powermac.c290
1 files changed, 290 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-powermac.c b/drivers/i2c/busses/i2c-powermac.c
new file mode 100644
index 00000000000..df786eb5529
--- /dev/null
+++ b/drivers/i2c/busses/i2c-powermac.c
@@ -0,0 +1,290 @@
+/*
+ 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.
+
+ You should have received a copy of the GNU General Public License
+ along with this program; if not, write to the Free Software
+ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include <linux/config.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/i2c.h>
+#include <linux/init.h>
+#include <linux/completion.h>
+#include <linux/device.h>
+#include <linux/platform_device.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;
+ u8 local[2];
+
+ rc = pmac_i2c_open(bus, 0);
+ if (rc)
+ return rc;
+
+ switch (size) {
+ case I2C_SMBUS_QUICK:
+ rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
+ if (rc)
+ goto bail;
+ rc = pmac_i2c_xfer(bus, addrdir, 0, 0, NULL, 0);
+ break;
+ case I2C_SMBUS_BYTE:
+ rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
+ if (rc)
+ goto bail;
+ rc = pmac_i2c_xfer(bus, addrdir, 0, 0, &data->byte, 1);
+ break;
+ case I2C_SMBUS_BYTE_DATA:
+ rc = pmac_i2c_setmode(bus, read ?
+ pmac_i2c_mode_combined :
+ pmac_i2c_mode_stdsub);
+ if (rc)
+ goto bail;
+ rc = pmac_i2c_xfer(bus, addrdir, 1, command, &data->byte, 1);
+ break;
+ case I2C_SMBUS_WORD_DATA:
+ rc = pmac_i2c_setmode(bus, read ?
+ pmac_i2c_mode_combined :
+ pmac_i2c_mode_stdsub);
+ if (rc)
+ goto bail;
+ if (!read) {
+ local[0] = data->word & 0xff;
+ local[1] = (data->word >> 8) & 0xff;
+ }
+ rc = pmac_i2c_xfer(bus, addrdir, 1, command, local, 2);
+ if (rc == 0 && read) {
+ data->word = ((u16)local[1]) << 8;
+ data->word |= local[0];
+ }
+ break;
+
+ /* Note that these are broken vs. the expected smbus API where
+ * on reads, the lenght 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:
+ rc = pmac_i2c_setmode(bus, read ?
+ pmac_i2c_mode_combined :
+ pmac_i2c_mode_stdsub);
+ if (rc)
+ goto bail;
+ rc = pmac_i2c_xfer(bus, addrdir, 1, command, data->block,
+ data->block[0] + 1);
+
+ break;
+ case I2C_SMBUS_I2C_BLOCK_DATA:
+ rc = pmac_i2c_setmode(bus, read ?
+ pmac_i2c_mode_combined :
+ pmac_i2c_mode_stdsub);
+ if (rc)
+ goto bail;
+ rc = pmac_i2c_xfer(bus, addrdir, 1, command,
+ read ? data->block : &data->block[1],
+ data->block[0]);
+ break;
+
+ default:
+ rc = -EINVAL;
+ }
+ 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 (num != 1)
+ return -EINVAL;
+ if (msgs->flags & I2C_M_TEN)
+ return -EINVAL;
+ read = (msgs->flags & I2C_M_RD) != 0;
+ addrdir = (msgs->addr << 1) | read;
+ if (msgs->flags & I2C_M_REV_DIR_ADDR)
+ addrdir ^= 1;
+
+ rc = pmac_i2c_open(bus, 0);
+ if (rc)
+ return rc;
+ rc = pmac_i2c_setmode(bus, pmac_i2c_mode_std);
+ if (rc)
+ goto bail;
+ rc = pmac_i2c_xfer(bus, addrdir, 0, 0, msgs->buf, msgs->len);
+ bail:
+ pmac_i2c_close(bus);
+ return rc < 0 ? rc : msgs->len;
+}
+
+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 struct i2c_algorithm i2c_powermac_algorithm = {
+ .smbus_xfer = i2c_powermac_smbus_xfer,
+ .master_xfer = i2c_powermac_master_xfer,
+ .functionality = i2c_powermac_func,
+};
+
+
+static int i2c_powermac_remove(struct device *dev)
+{
+ struct i2c_adapter *adapter = dev_get_drvdata(dev);
+ struct pmac_i2c_bus *bus = i2c_get_adapdata(adapter);
+ int rc;
+
+ rc = i2c_del_adapter(adapter);
+ pmac_i2c_detach_adapter(bus, adapter);
+ i2c_set_adapdata(adapter, NULL);
+ /* We aren't that prepared to deal with this... */
+ if (rc)
+ printk("i2c-powermac.c: Failed to remove bus %s !\n",
+ adapter->name);
+ dev_set_drvdata(dev, NULL);
+ kfree(adapter);
+
+ return 0;
+}
+
+
+static int i2c_powermac_probe(struct device *dev)
+{
+ struct pmac_i2c_bus *bus = dev->platform_data;
+ struct device_node *parent = NULL;
+ struct i2c_adapter *adapter;
+ char name[32], *basename;
+ int rc;
+
+ if (bus == NULL)
+ return -EINVAL;
+
+ /* 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(name, 32, "%s %d", basename, pmac_i2c_get_channel(bus));
+ of_node_put(parent);
+
+ adapter = kzalloc(sizeof(struct i2c_adapter), GFP_KERNEL);
+ if (adapter == NULL) {
+ printk(KERN_ERR "i2c-powermac: can't allocate inteface !\n");
+ return -ENOMEM;
+ }
+ dev_set_drvdata(dev, adapter);
+ strcpy(adapter->name, name);
+ adapter->algo = &i2c_powermac_algorithm;
+ i2c_set_adapdata(adapter, bus);
+ adapter->dev.parent = dev;
+ pmac_i2c_attach_adapter(bus, adapter);
+ rc = i2c_add_adapter(adapter);
+ if (rc) {
+ printk(KERN_ERR "i2c-powermac: Adapter %s registration "
+ "failed\n", name);
+ i2c_set_adapdata(adapter, NULL);
+ pmac_i2c_detach_adapter(bus, adapter);
+ }
+
+ printk(KERN_INFO "PowerMac i2c bus %s registered\n", name);
+ return rc;
+}
+
+
+static struct device_driver i2c_powermac_driver = {
+ .name = "i2c-powermac",
+ .bus = &platform_bus_type,
+ .probe = i2c_powermac_probe,
+ .remove = i2c_powermac_remove,
+};
+
+static int __init i2c_powermac_init(void)
+{
+ driver_register(&i2c_powermac_driver);
+ return 0;
+}
+
+
+static void __exit i2c_powermac_cleanup(void)
+{
+ driver_unregister(&i2c_powermac_driver);
+}
+
+module_init(i2c_powermac_init);
+module_exit(i2c_powermac_cleanup);
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