From: David Wu <david.wu@xxxxxxxxxxxxxx>
The i2c controller of new version1 supports highspeed mode,
1.7M and 3.4M rate. It also could be calculated divs by the rules.
The final divs would be effected a lot by hardware elements like
scl_rise_ns, scl_fall_ns and sda_rise_ns,sds_fall_ns.
Signed-off-by: David Wu <david.wu@xxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-rk3x.c | 56 ++++++++++++++++++++++++++++++++++++-------
1 file changed, 48 insertions(+), 8 deletions(-)
diff --git a/drivers/i2c/busses/i2c-rk3x.c b/drivers/i2c/busses/i2c-rk3x.c
index fae5099..ec0e37f 100644
--- a/drivers/i2c/busses/i2c-rk3x.c
+++ b/drivers/i2c/busses/i2c-rk3x.c
@@ -700,8 +700,8 @@ static int rk3x_i2c_v1_calc_divs(unsigned long clk_rate, unsigned long scl_rate,
int ret = 0;
- if (WARN_ON(scl_rate > 400000))
- scl_rate = 400000;
+ if (WARN_ON(scl_rate > 3400000))
+ scl_rate = 3400000;
if (WARN_ON(scl_rate < 100000))
scl_rate = 100000;
@@ -719,7 +719,7 @@ static int rk3x_i2c_v1_calc_divs(unsigned long clk_rate, unsigned long scl_rate,
start_setup_cnt = 0;
stop_setup_cnt = 0;
- } else {
+ } else if (scl_rate <= 400000) {
spec_min_setup_start = 600;
spec_min_hold_start = 600;
@@ -732,6 +732,32 @@ static int rk3x_i2c_v1_calc_divs(unsigned long clk_rate, unsigned long scl_rate,
start_setup_cnt = 0;
stop_setup_cnt = 0;
+ } else if (scl_rate <= 1700000) {
+ spec_min_low_ns = 320;
+ spec_min_high_ns = 120;
+
+ spec_min_setup_start = 160;
+ spec_min_hold_start = 160;
+
+ spec_max_data_hold_ns = 150;
+ spec_min_data_setup = 10;
+ spec_min_stop_setup = 160;
+
+ start_setup_cnt = 1;
+ stop_setup_cnt = 1;
+ } else {
+ spec_min_low_ns = 160;
+ spec_min_high_ns = 60;
+
+ spec_min_setup_start = 160;
+ spec_min_hold_start = 160;
+
+ spec_min_data_setup = 10;
+ spec_max_data_hold_ns = 70;
+ spec_min_stop_setup = 160;
+
+ start_setup_cnt = 2;
+ stop_setup_cnt = 2;
}
clk_rate_khz = DIV_ROUND_UP(clk_rate, 1000);
@@ -1126,15 +1152,29 @@ static int rk3x_i2c_probe(struct platform_device *pdev)
&i2c->scl_rise_ns)) {
if (i2c->scl_frequency <= 100000)
i2c->scl_rise_ns = 1000;
- else
+ else if (i2c->scl_frequency <= 400000)
i2c->scl_rise_ns = 300;
+ else if (i2c->scl_frequency <= 1700000)
+ i2c->scl_rise_ns = 80;
+ else
+ i2c->scl_rise_ns = 40;
}
if (of_property_read_u32(pdev->dev.of_node, "i2c-scl-falling-time-ns",
- &i2c->scl_fall_ns))
- i2c->scl_fall_ns = 300;
+ &i2c->scl_fall_ns)) {
+ if (i2c->scl_frequency <= 400000)
+ i2c->scl_fall_ns = 300;
+ else if (i2c->scl_frequency <= 1700000)
+ i2c->scl_fall_ns = 80;
+ else
+ i2c->scl_fall_ns = 40;
+ }
if (of_property_read_u32(pdev->dev.of_node, "i2c-sda-falling-time-ns",
- &i2c->scl_fall_ns))
- i2c->sda_fall_ns = i2c->scl_fall_ns;
+ &i2c->scl_fall_ns)) {
+ if (i2c->scl_frequency <= 400000)
+ i2c->sda_fall_ns = i2c->scl_fall_ns;
+ else
+ i2c->sda_fall_ns = 2 * i2c->scl_fall_ns;
+ }
strlcpy(i2c->adap.name, "rk3x-i2c", sizeof(i2c->adap.name));
i2c->adap.owner = THIS_MODULE;
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
