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/soc/intel/common/block/i2c/i2c.c | 10 ++++++++-- src/soc/intel/common/block/i2c/lpss_i2c.c | 15 ++++++++++----- src/soc/intel/common/block/i2c/lpss_i2c.h | 8 ++++++++ 3 files changed, 26 insertions(+), 7 deletions(-) (limited to 'src/soc/intel/common/block/i2c') diff --git a/src/soc/intel/common/block/i2c/i2c.c b/src/soc/intel/common/block/i2c/i2c.c index aeb6d8f2ed..625bb991d4 100644 --- a/src/soc/intel/common/block/i2c/i2c.c +++ b/src/soc/intel/common/block/i2c/i2c.c @@ -150,8 +150,14 @@ static void lpss_i2c_acpi_fill_ssdt(struct device *dev) acpigen_pop_len(); } -static struct i2c_bus_operations i2c_bus_ops = { - .dev_to_bus = &lpss_i2c_dev_to_bus, +static int lpss_i2c_dev_transfer(struct device *dev, + const struct i2c_msg *msg, size_t count) +{ + return lpss_i2c_transfer(lpss_i2c_dev_to_bus(dev), msg, count); +} + +static const struct i2c_bus_operations i2c_bus_ops = { + .transfer = lpss_i2c_dev_transfer, }; static struct device_operations i2c_dev_ops = { diff --git a/src/soc/intel/common/block/i2c/lpss_i2c.c b/src/soc/intel/common/block/i2c/lpss_i2c.c index 868a6ad300..7db3fe9668 100644 --- a/src/soc/intel/common/block/i2c/lpss_i2c.c +++ b/src/soc/intel/common/block/i2c/lpss_i2c.c @@ -258,7 +258,7 @@ static int lpss_i2c_wait_for_bus_idle(struct lpss_i2c_regs *regs) /* Transfer one byte of one segment, sending stop bit if requested */ static int lpss_i2c_transfer_byte(struct lpss_i2c_regs *regs, - struct i2c_msg *segment, + const struct i2c_msg *segment, size_t byte, int send_stop) { struct stopwatch sw; @@ -297,16 +297,15 @@ static int lpss_i2c_transfer_byte(struct lpss_i2c_regs *regs, return 0; } -/* Global I2C bus handler, defined in include/i2c.h */ -int platform_i2c_transfer(unsigned int bus, struct i2c_msg *segments, - int count) +int lpss_i2c_transfer(unsigned int bus, + const struct i2c_msg *segments, size_t count) { struct stopwatch sw; struct lpss_i2c_regs *regs; size_t byte; int ret = -1; - if (count <= 0 || !segments) + if (count == 0 || !segments) return -1; regs = (struct lpss_i2c_regs *)lpss_i2c_base_address(bus); @@ -396,6 +395,12 @@ out: return ret; } +/* Global I2C bus handler, defined in include/device/i2c_simple.h */ +int platform_i2c_transfer(unsigned int bus, struct i2c_msg *msg, int count) +{ + return lpss_i2c_transfer(bus, msg, count < 0 ? 0 : count); +} + static int lpss_i2c_set_speed_config(unsigned int bus, const struct lpss_i2c_speed_config *config) { diff --git a/src/soc/intel/common/block/i2c/lpss_i2c.h b/src/soc/intel/common/block/i2c/lpss_i2c.h index 2cb3d5ed52..72341621c0 100644 --- a/src/soc/intel/common/block/i2c/lpss_i2c.h +++ b/src/soc/intel/common/block/i2c/lpss_i2c.h @@ -89,3 +89,11 @@ int lpss_i2c_gen_speed_config(struct lpss_i2c_regs *regs, enum i2c_speed speed, const struct lpss_i2c_bus_config *bcfg, struct lpss_i2c_speed_config *config); + +/* + * Process given I2C segments in a single transfer + * Return value: + * -1 = failure + * 0 = success + */ +int lpss_i2c_transfer(unsigned int bus, const struct i2c_msg *, size_t count); -- cgit v1.2.3