| Message ID | a3bf32dadd9b0135442526cc77fec5726e6e617d.1555350118.git.vitor.soares@synopsys.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Fix i2c and i3c scl rate according bus mode | expand |
Hi Vitor, On Mon, 15 Apr 2019 20:46:42 +0200 Vitor Soares <vitor.soares@synopsys.com> wrote: > The i3c bus spec define a bus configuration where the i2c devices ^defines I2C devices... > doesn't have the 50ns filter yet they allow the SDR max speed. ^don't ^ a 50ns filter but support SCL running at SDR max rate (12MHz). > > This patch introduce the limited bus mode so the users can use ^introduces ^ so that users > a higher speed on presence of i2c devices index 1. ^in > > Signed-off-by: Vitor Soares <vitor.soares@synopsys.com> > Cc: Boris Brezillon <bbrezillon@kernel.org> > Cc: <linux-kernel@vger.kernel.org> > --- > drivers/i3c/master.c | 5 +++++ > include/linux/i3c/master.h | 5 +++++ > 2 files changed, 10 insertions(+) > > diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c > index 1c4a86a..46d3774 100644 > --- a/drivers/i3c/master.c > +++ b/drivers/i3c/master.c > @@ -463,6 +463,7 @@ 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", > }; > > @@ -575,6 +576,7 @@ 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) > @@ -2481,6 +2483,9 @@ 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 44fb3cf..740235e 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 allows > + * compliance up to the maximum SDR SCL clock > + * frequency. However they support SCL clock running at maximum SDR rate (12.5MHz). > * @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, > }; > The code itself looks good. Thanks, Boris
Hi Boris, From: Boris Brezillon <boris.brezillon@collabora.com> Date: Tue, Apr 16, 2019 at 07:00:49 > Hi Vitor, > > On Mon, 15 Apr 2019 20:46:42 +0200 > Vitor Soares <vitor.soares@synopsys.com> wrote: > > > The i3c bus spec define a bus configuration where the i2c devices > > ^defines I2C devices... > > > doesn't have the 50ns filter yet they allow the SDR max speed. > > ^don't ^ a 50ns filter but support SCL running at SDR max > rate (12MHz). > > > > > This patch introduce the limited bus mode so the users can use > > ^introduces ^ so that users > > > a higher speed on presence of i2c devices index 1. > > ^in > > > > > Signed-off-by: Vitor Soares <vitor.soares@synopsys.com> > > Cc: Boris Brezillon <bbrezillon@kernel.org> > > Cc: <linux-kernel@vger.kernel.org> > > --- > > drivers/i3c/master.c | 5 +++++ > > include/linux/i3c/master.h | 5 +++++ > > 2 files changed, 10 insertions(+) > > > > diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c > > index 1c4a86a..46d3774 100644 > > --- a/drivers/i3c/master.c > > +++ b/drivers/i3c/master.c > > @@ -463,6 +463,7 @@ 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", > > }; > > > > @@ -575,6 +576,7 @@ 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) > > @@ -2481,6 +2483,9 @@ 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 44fb3cf..740235e 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 allows > > + * compliance up to the maximum SDR SCL clock > > + * frequency. > > However they support > SCL clock running at maximum SDR rate > (12.5MHz). > > > * @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, > > }; > > > > The code itself looks good. > > Thanks, > > Boris Thanks for your feedback I will address the fixes next version. Best regards, Vitor Soares
diff --git a/drivers/i3c/master.c b/drivers/i3c/master.c index 1c4a86a..46d3774 100644 --- a/drivers/i3c/master.c +++ b/drivers/i3c/master.c @@ -463,6 +463,7 @@ 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", }; @@ -575,6 +576,7 @@ 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) @@ -2481,6 +2483,9 @@ 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 44fb3cf..740235e 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 allows + * 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, };
The i3c bus spec define a bus configuration where the i2c devices doesn't have the 50ns filter yet they allow the SDR max speed. This patch introduce the limited bus mode so the users can use a higher speed on 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> --- drivers/i3c/master.c | 5 +++++ include/linux/i3c/master.h | 5 +++++ 2 files changed, 10 insertions(+)