diff options
Diffstat (limited to 'src/device/i2c_bus.c')
| -rw-r--r-- | src/device/i2c_bus.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/src/device/i2c_bus.c b/src/device/i2c_bus.c new file mode 100644 index 0000000000..1c543efaba --- /dev/null +++ b/src/device/i2c_bus.c @@ -0,0 +1,161 @@ +/* + * This file is part of the coreboot project. + * + * 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; version 2 of the License. + * + * 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 <stdlib.h> +#include <stdint.h> +#include <console/console.h> +#include <device/smbus.h> +#include <device/i2c_bus.h> + +struct bus *i2c_link(struct device *const dev) +{ + if (!dev || !dev->bus) + return NULL; + + struct bus *link = dev->bus; + while (link) { + struct device *const parent = link->dev; + + if (parent && parent->ops && + (parent->ops->ops_i2c_bus || parent->ops->ops_smbus_bus)) + break; + + if (parent && parent->bus) + link = parent->bus; + else + link = NULL; + } + + if (!link) { + printk(BIOS_ALERT, "%s Cannot find I2C or SMBus bus operations", + dev_path(dev)); + } + + return link; +} + +int i2c_readb(struct device *const dev) +{ + struct device *const busdev = i2c_busdev(dev); + if (!busdev) + return -1; + + if (busdev->ops->ops_i2c_bus) { + uint8_t val; + const struct i2c_msg msg = { + .flags = I2C_M_RD, + .slave = dev->path.i2c.device, + .buf = &val, + .len = sizeof(val), + }; + + const int ret = busdev->ops->ops_i2c_bus-> + transfer(busdev, &msg, 1); + if (ret) + return ret; + else + return val; + } else if (busdev->ops->ops_smbus_bus->recv_byte) { + return busdev->ops->ops_smbus_bus->recv_byte(dev); + } else { + printk(BIOS_ERR, "%s Missing ops_smbus_bus->recv_byte", + dev_path(busdev)); + return -1; + } +} + +int i2c_writeb(struct device *const dev, uint8_t val) +{ + struct device *const busdev = i2c_busdev(dev); + if (!busdev) + return -1; + + if (busdev->ops->ops_i2c_bus) { + const struct i2c_msg msg = { + .flags = 0, + .slave = dev->path.i2c.device, + .buf = &val, + .len = sizeof(val), + }; + return busdev->ops->ops_i2c_bus->transfer(busdev, &msg, 1); + } else if (busdev->ops->ops_smbus_bus->send_byte) { + return busdev->ops->ops_smbus_bus->send_byte(dev, val); + } else { + printk(BIOS_ERR, "%s Missing ops_smbus_bus->send_byte", + dev_path(busdev)); + return -1; + } +} + +int i2c_readb_at(struct device *const dev, uint8_t off) +{ + struct device *const busdev = i2c_busdev(dev); + if (!busdev) + return -1; + + if (busdev->ops->ops_i2c_bus) { + uint8_t val; + const struct i2c_msg msg[] = { + { + .flags = 0, + .slave = dev->path.i2c.device, + .buf = &off, + .len = sizeof(off), + }, + { + .flags = I2C_M_RD, + .slave = dev->path.i2c.device, + .buf = &val, + .len = sizeof(val), + }, + }; + + const int ret = busdev->ops->ops_i2c_bus-> + transfer(busdev, msg, ARRAY_SIZE(msg)); + if (ret) + return ret; + else + return val; + } else if (busdev->ops->ops_smbus_bus->read_byte) { + return busdev->ops->ops_smbus_bus->read_byte(dev, off); + } else { + printk(BIOS_ERR, "%s Missing ops_smbus_bus->read_byte", + dev_path(busdev)); + return -1; + } +} + +int i2c_writeb_at(struct device *const dev, + const uint8_t off, const uint8_t val) +{ + struct device *const busdev = i2c_busdev(dev); + if (!busdev) + return -1; + + if (busdev->ops->ops_i2c_bus) { + uint8_t buf[] = { off, val }; + const struct i2c_msg msg = { + .flags = 0, + .slave = dev->path.i2c.device, + .buf = buf, + .len = sizeof(buf), + }; + return busdev->ops->ops_i2c_bus->transfer(busdev, &msg, 1); + } else if (busdev->ops->ops_smbus_bus->write_byte) { + return busdev->ops->ops_smbus_bus->write_byte(dev, off, val); + } else { + printk(BIOS_ERR, "%s Missing ops_smbus_bus->write_byte", + dev_path(busdev)); + return -1; + } +} |