| Message ID | 1462908794-27333-1-git-send-email-david.wu@rock-chips.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
? 2016?05?11? 03:33, David Wu ??: > Signed-off-by: David Wu <david.wu@rock-chips.com> > Reviewed-by: Douglas Anderson <dianders@chromium.org> Tested-by: Caesar Wang <wxt@rock-chips.com> > --- > Change in v8: > - None > > drivers/i2c/busses/i2c-rk3x.c | 21 +++++++++++++++++---- > 1 file changed, 17 insertions(+), 4 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c > index 25ed1ad..0ba25ee 100644 > --- a/drivers/i2c/busses/i2c-rk3x.c > +++ b/drivers/i2c/busses/i2c-rk3x.c > @@ -126,6 +126,17 @@ static const struct i2c_spec_values fast_mode_spec = { > .min_hold_buffer_ns = 1300, > }; > > +static const struct i2c_spec_values fast_mode_plus_spec = { > + .min_hold_start_ns = 260, > + .min_low_ns = 500, > + .min_high_ns = 260, > + .min_setup_start_ns = 260, > + .max_data_hold_ns = 400, > + .min_data_setup_ns = 50, > + .min_setup_stop_ns = 260, > + .min_hold_buffer_ns = 500, > +}; > + > /** > * struct rk3x_i2c_calced_timings: > * @div_low: Divider output for low > @@ -531,8 +542,10 @@ static const struct i2c_spec_values *rk3x_i2c_get_spec(unsigned int speed) > { > if (speed <= 100000) > return &standard_mode_spec; > - else > + else if (speed <= 400000) > return &fast_mode_spec; > + else > + return &fast_mode_plus_spec; > } > > /** > @@ -743,9 +756,9 @@ static int rk3x_i2c_v1_calc_timings(unsigned long clk_rate, > const struct i2c_spec_values *spec; > int ret = 0; > > - /* Support standard-mode and fast-mode */ > - if (WARN_ON(t->bus_freq_hz > 400000)) > - t->bus_freq_hz = 400000; > + /* Support standard-mode, fast-mode and fast-mode plus */ > + if (WARN_ON(t->bus_freq_hz > 1000000)) > + t->bus_freq_hz = 1000000; > > /* prevent scl_rate_khz from becoming 0 */ > if (WARN_ON(t->bus_freq_hz < 1000))
Am Mittwoch, 11. Mai 2016, 03:33:14 schrieb David Wu: please always try to also provide some sort of commit message. --- Implement fast mode plus that allows bus speeds of up to 1MHz. ..... --- Additionally, the i2c-noob in me would wish for a short sentence on where the timing values come from (measured, somewhere in the TRM I didn't find or something completely different). Patch content itself looks good, so with a suitable commit message, Reviewed-by: Heiko Stuebner <heiko@sntech.de> > Signed-off-by: David Wu <david.wu@rock-chips.com> > Reviewed-by: Douglas Anderson <dianders@chromium.org> > --- > Change in v8: > - None > > drivers/i2c/busses/i2c-rk3x.c | 21 +++++++++++++++++---- > 1 file changed, 17 insertions(+), 4 deletions(-) > > diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c > index 25ed1ad..0ba25ee 100644 > --- a/drivers/i2c/busses/i2c-rk3x.c > +++ b/drivers/i2c/busses/i2c-rk3x.c > @@ -126,6 +126,17 @@ static const struct i2c_spec_values fast_mode_spec = > { .min_hold_buffer_ns = 1300, > }; > > +static const struct i2c_spec_values fast_mode_plus_spec = { > + .min_hold_start_ns = 260, > + .min_low_ns = 500, > + .min_high_ns = 260, > + .min_setup_start_ns = 260, > + .max_data_hold_ns = 400, > + .min_data_setup_ns = 50, > + .min_setup_stop_ns = 260, > + .min_hold_buffer_ns = 500, > +}; > + > /** > * struct rk3x_i2c_calced_timings: > * @div_low: Divider output for low > @@ -531,8 +542,10 @@ static const struct i2c_spec_values > *rk3x_i2c_get_spec(unsigned int speed) { > if (speed <= 100000) > return &standard_mode_spec; > - else > + else if (speed <= 400000) > return &fast_mode_spec; > + else > + return &fast_mode_plus_spec; > } > > /** > @@ -743,9 +756,9 @@ static int rk3x_i2c_v1_calc_timings(unsigned long > clk_rate, const struct i2c_spec_values *spec; > int ret = 0; > > - /* Support standard-mode and fast-mode */ > - if (WARN_ON(t->bus_freq_hz > 400000)) > - t->bus_freq_hz = 400000; > + /* Support standard-mode, fast-mode and fast-mode plus */ > + if (WARN_ON(t->bus_freq_hz > 1000000)) > + t->bus_freq_hz = 1000000; > > /* prevent scl_rate_khz from becoming 0 */ > if (WARN_ON(t->bus_freq_hz < 1000))
Heiko, On Wed, May 11, 2016 at 2:09 PM, Heiko Stuebner <heiko@sntech.de> wrote: > Additionally, the i2c-noob in me would wish for a short sentence on where > the timing values come from (measured, somewhere in the TRM I didn't find or > something completely different). If you search for "UM10204" you'll find the first link is <http://www.nxp.com/documents/user_manual/UM10204.pdf>. That appears to be the official standard. At least that's what <http://www.i2c-bus.org/fast-mode-plus/> says (though they have an old link). Agree that it wouldn't hurt to mention that in the commit message. -Doug
Am Mittwoch, 11. Mai 2016, 16:41:54 schrieb Doug Anderson: > Heiko, > > On Wed, May 11, 2016 at 2:09 PM, Heiko Stuebner <heiko@sntech.de> wrote: > > Additionally, the i2c-noob in me would wish for a short sentence on > > where > > the timing values come from (measured, somewhere in the TRM I didn't > > find or something completely different). > > If you search for "UM10204" you'll find the first link is > <http://www.nxp.com/documents/user_manual/UM10204.pdf>. That appears > to be the official standard. At least that's what > <http://www.i2c-bus.org/fast-mode-plus/> says (though they have an old > link). I did find that document yesterday, but was to blind and somehow only saw the separate table for highspeed-timings. On a closer look, I now also found the timing-table for the other modes [due to the bigger font-size used there? ;-) ]
diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c index 25ed1ad..0ba25ee 100644 --- a/drivers/i2c/busses/i2c-rk3x.c +++ b/drivers/i2c/busses/i2c-rk3x.c @@ -126,6 +126,17 @@ static const struct i2c_spec_values fast_mode_spec = { .min_hold_buffer_ns = 1300, }; +static const struct i2c_spec_values fast_mode_plus_spec = { + .min_hold_start_ns = 260, + .min_low_ns = 500, + .min_high_ns = 260, + .min_setup_start_ns = 260, + .max_data_hold_ns = 400, + .min_data_setup_ns = 50, + .min_setup_stop_ns = 260, + .min_hold_buffer_ns = 500, +}; + /** * struct rk3x_i2c_calced_timings: * @div_low: Divider output for low @@ -531,8 +542,10 @@ static const struct i2c_spec_values *rk3x_i2c_get_spec(unsigned int speed) { if (speed <= 100000) return &standard_mode_spec; - else + else if (speed <= 400000) return &fast_mode_spec; + else + return &fast_mode_plus_spec; } /** @@ -743,9 +756,9 @@ static int rk3x_i2c_v1_calc_timings(unsigned long clk_rate, const struct i2c_spec_values *spec; int ret = 0; - /* Support standard-mode and fast-mode */ - if (WARN_ON(t->bus_freq_hz > 400000)) - t->bus_freq_hz = 400000; + /* Support standard-mode, fast-mode and fast-mode plus */ + if (WARN_ON(t->bus_freq_hz > 1000000)) + t->bus_freq_hz = 1000000; /* prevent scl_rate_khz from becoming 0 */ if (WARN_ON(t->bus_freq_hz < 1000))