Implement fast mode plus that allows bus speeds of up to 1MHz.
Signed-off-by: David Wu <david.wu@xxxxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
Tested-by: Caesar Wang <wxt@xxxxxxxxxxxxxx>
Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx>
---
Change in v9:
- add commit message
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 673656e..ba4ce39 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))
--
1.9.1
--
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