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i2c: Move to Linux like struct i2c_msg

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Our current struct for I2C segments `i2c_seg` was close to being compa-
tible to the Linux version `i2c_msg`, close to being compatible to SMBus
and close to being readable (e.g. what was `chip` supposed to mean?) but
turned out to be hard to fix.

Instead of extending it in a backwards compatible way (and not touching
current controller drivers), replace it with a Linux source compatible
`struct i2c_msg` and patch all the drivers and users with Coccinelle.

The new `struct i2c_msg` should ease porting drivers from Linux and help
to write SMBus compatible controller drivers.

Beside integer type changes, the field `read` is replaced with a generic
field `flags` and `chip` is renamed to `slave`.

Patched with Coccinelle using the clumsy spatch below and some manual
changes:

* Nested struct initializers and one field access skipped by Coccinelle.
* Removed assumption in the code that I2C_M_RD is 1.
* In `i2c.h`, changed all occurences of `chip` to `slave`.

    @@ @@
    -struct i2c_seg
    +struct i2c_msg

    @@ identifier msg; expression e; @@
    (
     struct i2c_msg msg = {
    -    .read = 0,
    +    .flags = 0,
     };
    |
     struct i2c_msg msg = {
    -    .read = 1,
    +    .flags = I2C_M_RD,
     };
    |
     struct i2c_msg msg = {
    -    .chip = e,
    +    .slave = e,
     };
    )

    @@ struct i2c_msg msg; statement S1, S2; @@
    (
    -if (msg.read)
    +if (msg.flags & I2C_M_RD)
     S1 else S2
    |
    -if (msg.read)
    +if (msg.flags & I2C_M_RD)
     S1
    )

    @@ struct i2c_msg *msg; statement S1, S2; @@
    (
    -if (msg->read)
    +if (msg->flags & I2C_M_RD)
     S1 else S2
    |
    -if (msg->read)
    +if (msg->flags & I2C_M_RD)
     S1
    )

    @@ struct i2c_msg msg; expression e; @@
    (
    -msg.read = 0;
    +msg.flags = 0;
    |
    -msg.read = 1;
    +msg.flags = I2C_M_RD;
    |
    -msg.read = e;
    +msg.flags = e ? I2C_M_RD : 0;
    |
    -!!(msg.read)
    +(msg.flags & I2C_M_RD)
    |
    -(msg.read)
    +(msg.flags & I2C_M_RD)
    )

    @@ struct i2c_msg *msg; expression e; @@
    (
    -msg->read = 0;
    +msg->flags = 0;
    |
    -msg->read = 1;
    +msg->flags = I2C_M_RD;
    |
    -msg->read = e;
    +msg->flags = e ? I2C_M_RD : 0;
    |
    -!!(msg->read)
    +(msg->flags & I2C_M_RD)
    |
    -(msg->read)
    +(msg->flags & I2C_M_RD)
    )

    @@ struct i2c_msg msg; @@
    -msg.chip
    +msg.slave

    @@ struct i2c_msg *msg; expression e; @@
    -msg[e].chip
    +msg[e].slave

    @ slave disable ptr_to_array @ struct i2c_msg *msg; @@
    -msg->chip
    +msg->slave

Change-Id: Ifd7cabf0a18ffd7a1def25d1d7059b713d0b7ea9
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/20542
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
This commit is contained in:
Nico Huber
2017-07-12 17:59:16 +02:00
committed by Martin Roth
parent 673e014fab
commit 029dfff30c
17 changed files with 192 additions and 144 deletions
Download Patch File Download Diff File Expand all files Collapse all files

23
src/soc/mediatek/mt8173/i2c.c
View File

@@ -136,7 +136,7 @@ static inline void mtk_i2c_dump_info(uint8_t bus)
I2CLOG("addr address %x\n", (uint32_t)regs);
}
static uint32_t mtk_i2c_transfer(uint8_t bus, struct i2c_seg *seg,
static uint32_t mtk_i2c_transfer(uint8_t bus, struct i2c_msg *seg,
enum i2c_modes read)
{
uint32_t ret_code = I2C_OK;
@@ -154,7 +154,7 @@ static uint32_t mtk_i2c_transfer(uint8_t bus, struct i2c_seg *seg,
regs = i2c[bus].i2c_regs;
dma_regs = i2c[bus].i2c_dma_regs;
addr = seg[0].chip;
addr = seg[0].slave;
switch (read) {
case I2C_WRITE_MODE:
@@ -305,26 +305,31 @@ static uint32_t mtk_i2c_transfer(uint8_t bus, struct i2c_seg *seg,
return ret_code;
}
static uint8_t mtk_i2c_should_combine(struct i2c_seg *seg, int left_count)
static uint8_t mtk_i2c_should_combine(struct i2c_msg *seg, int left_count)
{
if (left_count >= 2 && seg[0].read == 0 && seg[1].read == 1 &&
seg[0].chip == seg[1].chip)
if (left_count >= 2 &&
!(seg[0].flags & I2C_M_RD) &&
(seg[1].flags & I2C_M_RD) &&
seg[0].slave == seg[1].slave)
return 1;
else
return 0;
}
int platform_i2c_transfer(unsigned bus, struct i2c_seg *segments, int seg_count)
int platform_i2c_transfer(unsigned bus, struct i2c_msg *segments,
int seg_count)
{
int ret = 0;
int i;
int read;
for (i = 0; i < seg_count; i++) {
if (mtk_i2c_should_combine(&segments[i], seg_count - i))
if (mtk_i2c_should_combine(&segments[i], seg_count - i)) {
read = I2C_WRITE_READ_MODE;
else
read = segments[i].read;
} else {
read = (segments[i].flags & I2C_M_RD) ?
I2C_READ_MODE : I2C_WRITE_MODE;
}
ret = mtk_i2c_transfer(bus, &segments[i], read);