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path: root/drivers/i2c/busses/i2c-pmac-smu.c
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Diffstat (limited to 'drivers/i2c/busses/i2c-pmac-smu.c')
-rw-r--r--drivers/i2c/busses/i2c-pmac-smu.c316
1 files changed, 316 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-pmac-smu.c b/drivers/i2c/busses/i2c-pmac-smu.c
new file mode 100644
index 000000000000..8a9f5648a23d
--- /dev/null
+++ b/drivers/i2c/busses/i2c-pmac-smu.c
@@ -0,0 +1,316 @@
+/*
+ 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 <asm/prom.h>
+#include <asm/of_device.h>
+#include <asm/smu.h>
+
+static int probe;
+
+MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>");
+MODULE_DESCRIPTION("I2C driver for Apple's SMU");
+MODULE_LICENSE("GPL");
+module_param(probe, bool, 0);
+
+
+/* Physical interface */
+struct smu_iface
+{
+ struct i2c_adapter adapter;
+ struct completion complete;
+ u32 busid;
+};
+
+static void smu_i2c_done(struct smu_i2c_cmd *cmd, void *misc)
+{
+ struct smu_iface *iface = misc;
+ complete(&iface->complete);
+}
+
+/*
+ * SMBUS-type transfer entrypoint
+ */
+static s32 smu_smbus_xfer( struct i2c_adapter* adap,
+ u16 addr,
+ unsigned short flags,
+ char read_write,
+ u8 command,
+ int size,
+ union i2c_smbus_data* data)
+{
+ struct smu_iface *iface = i2c_get_adapdata(adap);
+ struct smu_i2c_cmd cmd;
+ int rc = 0;
+ int read = (read_write == I2C_SMBUS_READ);
+
+ cmd.info.bus = iface->busid;
+ cmd.info.devaddr = (addr << 1) | (read ? 0x01 : 0x00);
+
+ /* Prepare datas & select mode */
+ switch (size) {
+ case I2C_SMBUS_QUICK:
+ cmd.info.type = SMU_I2C_TRANSFER_SIMPLE;
+ cmd.info.datalen = 0;
+ break;
+ case I2C_SMBUS_BYTE:
+ cmd.info.type = SMU_I2C_TRANSFER_SIMPLE;
+ cmd.info.datalen = 1;
+ if (!read)
+ cmd.info.data[0] = data->byte;
+ break;
+ case I2C_SMBUS_BYTE_DATA:
+ cmd.info.type = SMU_I2C_TRANSFER_STDSUB;
+ cmd.info.datalen = 1;
+ cmd.info.sublen = 1;
+ cmd.info.subaddr[0] = command;
+ cmd.info.subaddr[1] = 0;
+ cmd.info.subaddr[2] = 0;
+ if (!read)
+ cmd.info.data[0] = data->byte;
+ break;
+ case I2C_SMBUS_WORD_DATA:
+ cmd.info.type = SMU_I2C_TRANSFER_STDSUB;
+ cmd.info.datalen = 2;
+ cmd.info.sublen = 1;
+ cmd.info.subaddr[0] = command;
+ cmd.info.subaddr[1] = 0;
+ cmd.info.subaddr[2] = 0;
+ if (!read) {
+ cmd.info.data[0] = data->byte & 0xff;
+ cmd.info.data[1] = (data->byte >> 8) & 0xff;
+ }
+ 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 ...
+ */
+ case I2C_SMBUS_BLOCK_DATA:
+ cmd.info.type = SMU_I2C_TRANSFER_STDSUB;
+ cmd.info.datalen = data->block[0] + 1;
+ if (cmd.info.datalen > 6)
+ return -EINVAL;
+ if (!read)
+ memcpy(cmd.info.data, data->block, cmd.info.datalen);
+ cmd.info.sublen = 1;
+ cmd.info.subaddr[0] = command;
+ cmd.info.subaddr[1] = 0;
+ cmd.info.subaddr[2] = 0;
+ break;
+ case I2C_SMBUS_I2C_BLOCK_DATA:
+ cmd.info.type = SMU_I2C_TRANSFER_STDSUB;
+ cmd.info.datalen = data->block[0];
+ if (cmd.info.datalen > 7)
+ return -EINVAL;
+ if (!read)
+ memcpy(cmd.info.data, &data->block[1],
+ cmd.info.datalen);
+ cmd.info.sublen = 1;
+ cmd.info.subaddr[0] = command;
+ cmd.info.subaddr[1] = 0;
+ cmd.info.subaddr[2] = 0;
+ break;
+
+ default:
+ return -EINVAL;
+ }
+
+ /* Turn a standardsub read into a combined mode access */
+ if (read_write == I2C_SMBUS_READ &&
+ cmd.info.type == SMU_I2C_TRANSFER_STDSUB)
+ cmd.info.type = SMU_I2C_TRANSFER_COMBINED;
+
+ /* Finish filling command and submit it */
+ cmd.done = smu_i2c_done;
+ cmd.misc = iface;
+ rc = smu_queue_i2c(&cmd);
+ if (rc < 0)
+ return rc;
+ wait_for_completion(&iface->complete);
+ rc = cmd.status;
+
+ if (!read || rc < 0)
+ return rc;
+
+ switch (size) {
+ case I2C_SMBUS_BYTE:
+ case I2C_SMBUS_BYTE_DATA:
+ data->byte = cmd.info.data[0];
+ break;
+ case I2C_SMBUS_WORD_DATA:
+ data->word = ((u16)cmd.info.data[1]) << 8;
+ data->word |= cmd.info.data[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 ...
+ */
+ case I2C_SMBUS_BLOCK_DATA:
+ case I2C_SMBUS_I2C_BLOCK_DATA:
+ memcpy(&data->block[0], cmd.info.data, cmd.info.datalen);
+ break;
+ }
+
+ return rc;
+}
+
+static u32
+smu_smbus_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;
+}
+
+/* For now, we only handle combined mode (smbus) */
+static struct i2c_algorithm smu_algorithm = {
+ .smbus_xfer = smu_smbus_xfer,
+ .functionality = smu_smbus_func,
+};
+
+static int create_iface(struct device_node *np, struct device *dev)
+{
+ struct smu_iface* iface;
+ u32 *reg, busid;
+ int rc;
+
+ reg = (u32 *)get_property(np, "reg", NULL);
+ if (reg == NULL) {
+ printk(KERN_ERR "i2c-pmac-smu: can't find bus number !\n");
+ return -ENXIO;
+ }
+ busid = *reg;
+
+ iface = kmalloc(sizeof(struct smu_iface), GFP_KERNEL);
+ if (iface == NULL) {
+ printk(KERN_ERR "i2c-pmac-smu: can't allocate inteface !\n");
+ return -ENOMEM;
+ }
+ memset(iface, 0, sizeof(struct smu_iface));
+ init_completion(&iface->complete);
+ iface->busid = busid;
+
+ dev_set_drvdata(dev, iface);
+
+ sprintf(iface->adapter.name, "smu-i2c-%02x", busid);
+ iface->adapter.algo = &smu_algorithm;
+ iface->adapter.algo_data = NULL;
+ iface->adapter.client_register = NULL;
+ iface->adapter.client_unregister = NULL;
+ i2c_set_adapdata(&iface->adapter, iface);
+ iface->adapter.dev.parent = dev;
+
+ rc = i2c_add_adapter(&iface->adapter);
+ if (rc) {
+ printk(KERN_ERR "i2c-pamc-smu.c: Adapter %s registration "
+ "failed\n", iface->adapter.name);
+ i2c_set_adapdata(&iface->adapter, NULL);
+ }
+
+ if (probe) {
+ unsigned char addr;
+ printk("Probe: ");
+ for (addr = 0x00; addr <= 0x7f; addr++) {
+ if (i2c_smbus_xfer(&iface->adapter,addr,
+ 0,0,0,I2C_SMBUS_QUICK,NULL) >= 0)
+ printk("%02x ", addr);
+ }
+ printk("\n");
+ }
+
+ printk(KERN_INFO "SMU i2c bus %x registered\n", busid);
+
+ return 0;
+}
+
+static int dispose_iface(struct device *dev)
+{
+ struct smu_iface *iface = dev_get_drvdata(dev);
+ int rc;
+
+ rc = i2c_del_adapter(&iface->adapter);
+ i2c_set_adapdata(&iface->adapter, NULL);
+ /* We aren't that prepared to deal with this... */
+ if (rc)
+ printk("i2c-pmac-smu.c: Failed to remove bus %s !\n",
+ iface->adapter.name);
+ dev_set_drvdata(dev, NULL);
+ kfree(iface);
+
+ return 0;
+}
+
+
+static int create_iface_of_platform(struct of_device* dev,
+ const struct of_device_id *match)
+{
+ return create_iface(dev->node, &dev->dev);
+}
+
+
+static int dispose_iface_of_platform(struct of_device* dev)
+{
+ return dispose_iface(&dev->dev);
+}
+
+
+static struct of_device_id i2c_smu_match[] =
+{
+ {
+ .compatible = "smu-i2c",
+ },
+ {},
+};
+static struct of_platform_driver i2c_smu_of_platform_driver =
+{
+ .name = "i2c-smu",
+ .match_table = i2c_smu_match,
+ .probe = create_iface_of_platform,
+ .remove = dispose_iface_of_platform
+};
+
+
+static int __init i2c_pmac_smu_init(void)
+{
+ of_register_driver(&i2c_smu_of_platform_driver);
+ return 0;
+}
+
+
+static void __exit i2c_pmac_smu_cleanup(void)
+{
+ of_unregister_driver(&i2c_smu_of_platform_driver);
+}
+
+module_init(i2c_pmac_smu_init);
+module_exit(i2c_pmac_smu_cleanup);
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