From 581738642fbeacdf97fc737a41b3128d72cf1a1c Mon Sep 17 00:00:00 2001 From: Nico Huber Date: Tue, 1 Aug 2017 17:09:35 +0200 Subject: Reinvent I2C ops MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Do not use the global platform_i2c_transfer() function that can only be implemented by a single driver. Instead, make a `struct device` aware transfer() function the only interface function for I2C controller dri- vers to implement. To not force the slave device drivers to be implemented either above generic I2C or specialized SMBus operations, we support SMBus control- lers in the slave device interface too. We start with four simple slave functions: i2c_readb(), i2c_writeb(), i2c_readb_at() and i2c_writeb_at(). They are all compatible to respec- tive SMBus functions. But we keep aliases because it would be weird to force e.g. an I2C EEPROM driver to call smbus_read_byte(). Change-Id: I98386f91bf4799ba3df84ec8bc0f64edd4142818 Signed-off-by: Nico Huber Reviewed-on: https://review.coreboot.org/20846 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin Reviewed-by: Kyösti Mälkki --- src/device/Makefile.inc | 1 + src/device/i2c.c | 83 ------------------------- src/device/i2c_bus.c | 161 ++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 162 insertions(+), 83 deletions(-) create mode 100644 src/device/i2c_bus.c (limited to 'src/device') diff --git a/src/device/Makefile.inc b/src/device/Makefile.inc index 8e6bf5be60..a1d592051b 100644 --- a/src/device/Makefile.inc +++ b/src/device/Makefile.inc @@ -37,3 +37,4 @@ bootblock-y += i2c.c verstage-y += i2c.c romstage-y += i2c.c ramstage-y += i2c.c +ramstage-y += i2c_bus.c diff --git a/src/device/i2c.c b/src/device/i2c.c index 6fdd5cff26..aa695caf03 100644 --- a/src/device/i2c.c +++ b/src/device/i2c.c @@ -13,92 +13,9 @@ * GNU General Public License for more details. */ -#include -#include #include #include -#if ENV_RAMSTAGE -/* Return I2C operations for a bus */ -static inline const struct i2c_bus_operations *ops_i2c_bus(struct bus *bus) -{ - if (bus && bus->dev && bus->dev->ops) - return bus->dev->ops->ops_i2c_bus; - return NULL; -} - -int i2c_dev_find_bus(struct device *dev) -{ - const struct i2c_bus_operations *ops; - struct bus *pbus; - - if (!dev) - return -1; - - /* Locate parent bus with I2C controller ops */ - pbus = dev->bus; - while (pbus && pbus->dev && !ops_i2c_bus(pbus)) - if (pbus->dev->bus != pbus) - pbus = pbus->dev->bus; - - /* Check if this I2C controller ops implements dev_to_bus() */ - ops = ops_i2c_bus(pbus); - if (!ops || !ops->dev_to_bus) - return -1; - - /* Use controller ops to determine the bus number */ - return ops->dev_to_bus(pbus->dev); -} - -int i2c_dev_transfer(struct device *dev, struct i2c_msg *segments, int count) -{ - int bus = i2c_dev_find_bus(dev); - if (bus < 0) - return -1; - return i2c_transfer(bus, segments, count); -} - -int i2c_dev_readb(struct device *dev, uint8_t reg, uint8_t *data) -{ - int bus = i2c_dev_find_bus(dev); - if (bus < 0) - return -1; - return i2c_readb(bus, dev->path.i2c.device, reg, data); -} - -int i2c_dev_writeb(struct device *dev, uint8_t reg, uint8_t data) -{ - int bus = i2c_dev_find_bus(dev); - if (bus < 0) - return -1; - return i2c_writeb(bus, dev->path.i2c.device, reg, data); -} - -int i2c_dev_read_bytes(struct device *dev, uint8_t reg, uint8_t *data, int len) -{ - int bus = i2c_dev_find_bus(dev); - if (bus < 0) - return -1; - return i2c_read_bytes(bus, dev->path.i2c.device, reg, data, len); -} - -int i2c_dev_read_raw(struct device *dev, uint8_t *data, int len) -{ - int bus = i2c_dev_find_bus(dev); - if (bus < 0) - return -1; - return i2c_read_raw(bus, dev->path.i2c.device, data, len); -} - -int i2c_dev_write_raw(struct device *dev, uint8_t *data, int len) -{ - int bus = i2c_dev_find_bus(dev); - if (bus < 0) - return -1; - return i2c_write_raw(bus, dev->path.i2c.device, data, len); -} -#endif - int i2c_read_field(unsigned bus, uint8_t chip, uint8_t reg, uint8_t *data, uint8_t mask, uint8_t shift) { 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 +#include +#include +#include +#include + +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; + } +} -- cgit v1.2.3