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| author | Vitor Soares <Vitor.Soares@synopsys.com> | 2019-06-19 20:36:32 +0200 |
|---|---|---|
| committer | Boris Brezillon <boris.brezillon@collabora.com> | 2019-06-20 09:23:22 +0200 |
| commit | cbf4f7325a638ced1d815580dfed44ea3b76163c (patch) | |
| tree | 14967988fe09d6e065c323afe1f47b6f9f87048c | |
| parent | i3c: fix i2c and i3c scl rate by bus mode (diff) | |
| download | linux-cbf4f7325a638ced1d815580dfed44ea3b76163c.tar.xz linux-cbf4f7325a638ced1d815580dfed44ea3b76163c.zip | |
i3c: add mixed limited bus mode
The i3c bus spec defines a bus configuration where i2c devices don't
have a 50ns filter but support SCL running at SDR max rate (12.5MHz).
This patch introduces the limited bus mode so that users can use
a higher speed in presence of i2c devices index 1.
Signed-off-by: Vitor Soares <vitor.soares@synopsys.com>
Cc: Boris Brezillon <bbrezillon@kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Signed-off-by: Boris Brezillon <boris.brezillon@collabora.com>
| -rw-r--r-- | drivers/i3c/master.c | 5 | ||||
| -rw-r--r-- | include/linux/i3c/master.h | 5 |
2 files changed, 10 insertions, 0 deletions
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index 54026be03998..1318adfe0216 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -470,6 +470,7 @@ static int i3c_bus_init(struct i3c_bus *i3cbus) static const char * const i3c_bus_mode_strings[] = { [I3C_BUS_MODE_PURE] = "pure", [I3C_BUS_MODE_MIXED_FAST] = "mixed-fast", + [I3C_BUS_MODE_MIXED_LIMITED] = "mixed-limited", [I3C_BUS_MODE_MIXED_SLOW] = "mixed-slow", }; @@ -584,6 +585,7 @@ int i3c_bus_set_mode(struct i3c_bus *i3cbus, enum i3c_bus_mode mode, i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE; break; case I3C_BUS_MODE_MIXED_FAST: + case I3C_BUS_MODE_MIXED_LIMITED: if (!i3cbus->scl_rate.i3c) i3cbus->scl_rate.i3c = I3C_BUS_TYP_I3C_SCL_RATE; if (!i3cbus->scl_rate.i2c) @@ -2487,6 +2489,9 @@ int i3c_master_register(struct i3c_master_controller *master, mode = I3C_BUS_MODE_MIXED_FAST; break; case I3C_LVR_I2C_INDEX(1): + if (mode < I3C_BUS_MODE_MIXED_LIMITED) + mode = I3C_BUS_MODE_MIXED_LIMITED; + break; case I3C_LVR_I2C_INDEX(2): if (mode < I3C_BUS_MODE_MIXED_SLOW) mode = I3C_BUS_MODE_MIXED_SLOW; diff --git a/include/linux/i3c/master.h b/include/linux/i3c/master.h index eca8337bdaa5..1f08fa8d69d2 100644 --- a/include/linux/i3c/master.h +++ b/include/linux/i3c/master.h @@ -250,12 +250,17 @@ struct i3c_device { * the bus. The only impact in this mode is that the * high SCL pulse has to stay below 50ns to trick I2C * devices when transmitting I3C frames + * @I3C_BUS_MODE_MIXED_LIMITED: I2C devices without 50ns spike filter are + * present on the bus. However they allow + * compliance up to the maximum SDR SCL clock + * frequency. * @I3C_BUS_MODE_MIXED_SLOW: I2C devices without 50ns spike filter are present * on the bus */ enum i3c_bus_mode { I3C_BUS_MODE_PURE, I3C_BUS_MODE_MIXED_FAST, + I3C_BUS_MODE_MIXED_LIMITED, I3C_BUS_MODE_MIXED_SLOW, }; |