From 029dfff30cc468b3e21c2004a135d3380a8c20e6 Mon Sep 17 00:00:00 2001 From: Nico Huber Date: Wed, 12 Jul 2017 17:59:16 +0200 Subject: i2c: Move to Linux like `struct i2c_msg` MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-on: https://review.coreboot.org/20542 Tested-by: build bot (Jenkins) Reviewed-by: Aaron Durbin Reviewed-by: Werner Zeh Reviewed-by: Kyösti Mälkki Reviewed-by: Paul Menzel --- src/soc/mediatek/mt8173/i2c.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) (limited to 'src/soc/mediatek/mt8173/i2c.c') diff --git a/src/soc/mediatek/mt8173/i2c.c b/src/soc/mediatek/mt8173/i2c.c index f07ffc92ab..1d541e5d0f 100644 --- a/src/soc/mediatek/mt8173/i2c.c +++ b/src/soc/mediatek/mt8173/i2c.c @@ -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); -- cgit v1.2.3