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| author | Ting Shen <phoenixshen@google.com> | 2019-10-23 20:02:10 +0800 |
|---|---|---|
| committer | Commit Bot <commit-bot@chromium.org> | 2019-12-16 08:06:04 +0000 |
| commit | 7b61704fd1a09c5aae26f163e096d9695e479f21 (patch) | |
| tree | 2692c9bdf01c6a73625b46c3bc5092bbb9ffaf06 /include/i2c_bitbang.h | |
| parent | 7c89289e32ba60dca6d00aca6827b6ebe82f87ba (diff) | |
| download | chrome-ec-7b61704fd1a09c5aae26f163e096d9695e479f21.tar.gz | |
i2c: add support for i2c bit-banging
Krane/Jacuzzi need a 100KHz SMBus port for battery, in addition to the
existing two i2c ports.
This CL adds a bit-bang driver that supports i2c/smbus bit-banging
through a set of pre-defined gpio pins.
BUG=b:138161741,b:138415463
TEST=On a reworked jacuzzi (battery i2c connected to other gpios),
1) `battery` shows reasonable output (this verifies i2c_readN,
i2c_read_string)
2) `i2cscan` works for port 3 (bitbang port)
3) `cutoff` (verifies i2c_writeN)
4) `i2ctest` stress test
BRANCH=master
Change-Id: I78020e5c51707c3d9f0fd54f2c299e2f29cabe2f
Signed-off-by: Ting Shen <phoenixshen@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1765110
Reviewed-by: Alexandru M Stan <amstan@chromium.org>
Commit-Queue: Ting Shen <phoenixshen@chromium.org>
Tested-by: Ting Shen <phoenixshen@chromium.org>
Diffstat (limited to 'include/i2c_bitbang.h')
| -rw-r--r-- | include/i2c_bitbang.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/include/i2c_bitbang.h b/include/i2c_bitbang.h new file mode 100644 index 0000000000..f3c07baf76 --- /dev/null +++ b/include/i2c_bitbang.h @@ -0,0 +1,23 @@ +/* Copyright 2019 The Chromium OS Authors. All rights reserved. + * Use of this source code is governed by a BSD-style license that can be + * found in the LICENSE file. + */ +#ifndef __CROS_EC_I2C_BITBANG_H +#define __CROS_EC_I2C_BITBANG_H + +#include "i2c.h" + +extern const struct i2c_drv bitbang_drv; + +extern const struct i2c_port_t i2c_bitbang_ports[]; +extern const unsigned int i2c_bitbang_ports_used; + +/* expose static functions for testing */ +#ifdef TEST_BUILD +int bitbang_start_cond(const struct i2c_port_t *i2c_port); +void bitbang_stop_cond(const struct i2c_port_t *i2c_port); +int bitbang_write_byte(const struct i2c_port_t *i2c_port, uint8_t byte); +void bitbang_set_started(int val); +#endif + +#endif /* __CROS_EC_I2C_BITBANG_H */ |