diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-pmac-smu.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-pmac-smu.c | 315 |
1 files changed, 315 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..bfefe7f7a53d --- /dev/null +++ b/drivers/i2c/busses/i2c-pmac-smu.c @@ -0,0 +1,315 @@ +/* + 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 = kzalloc(sizeof(struct smu_iface), GFP_KERNEL); + if (iface == NULL) { + printk(KERN_ERR "i2c-pmac-smu: can't allocate inteface !\n"); + return -ENOMEM; + } + 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); |