3 files changed, 329 insertions, 0 deletions

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 8334496a7e0a..3badfec75b1c 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -245,6 +245,18 @@ config I2C_KEYWEST
           This support is also available as a module.  If so, the module 
           will be called i2c-keywest.
 
+config I2C_PMAC_SMU
+        tristate "Powermac SMU I2C interface"
+        depends on I2C && PMAC_SMU
+        help
+          This supports the use of the I2C interface in the SMU
+          chip on recent Apple machines like the iMac G5.  It is used
+          among others by the thermal control driver for those machines.
+          Say Y if you have such a machine.
+
+          This support is also available as a module.  If so, the module
+          will be called i2c-pmac-smu.
+
 config I2C_MPC
         tristate "MPC107/824x/85xx/52xx"
         depends on I2C && PPC32
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 980b3e983670..f1df00f66c6c 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -20,6 +20,7 @@ obj-$(CONFIG_I2C_ITE)		+= i2c-ite.o
 obj-$(CONFIG_I2C_IXP2000)       += i2c-ixp2000.o
 obj-$(CONFIG_I2C_IXP4XX)        += i2c-ixp4xx.o
 obj-$(CONFIG_I2C_KEYWEST)       += i2c-keywest.o
+obj-$(CONFIG_I2C_PMAC_SMU)      += i2c-pmac-smu.o
 obj-$(CONFIG_I2C_MPC)           += i2c-mpc.o
 obj-$(CONFIG_I2C_MV64XXX)       += i2c-mv64xxx.o
 obj-$(CONFIG_I2C_NFORCE2)       += i2c-nforce2.o
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);