[v9,8/8] i2c: rk3x: support fast-mode plus for rk3399

Commit Message

David Wu May 12, 2016, 8:01 a.m. UTC

Implement fast mode plus that allows bus speeds of up to 1MHz.

Signed-off-by: David Wu <[e-mail]>
Reviewed-by: Douglas Anderson <[e-mail]>
Tested-by: Caesar Wang <[e-mail]>
Reviewed-by: Heiko Stuebner <[e-mail]>
---
Change in v9:
- add commit message

Change in v8:
- none

 drivers/i2c/busses/i2c-rk3x.c | 21 +++++++++++++++++----
 1 file changed, 17 insertions(+), 4 deletions(-)

Patch

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))