On 05/29/2018 04:54 PM, Andy Shevchenko wrote:
On Tue, 2018-05-29 at 14:27 +0300, Jarkko Nikula wrote:
Trivial added debug print for dev->clk_freq doesn't necessarily tell
the
actual bus speed or mode the controller is operating. For instance it
may indicate 1 MHz Fast Mode Plus or 3.4 MHz High Speed but driver
ends up
using 400 kHz Fast Mode due missing timing parameters or missing
support
from HW.
Add a debug print that prints the bus speed based on the validated
speed
that gets programmed into a HW.
Signed-off-by: Jarkko Nikula <jarkko.nikula@xxxxxxxxxxxxxxx>
---
drivers/i2c/busses/i2c-designware-master.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/drivers/i2c/busses/i2c-designware-master.c
b/drivers/i2c/busses/i2c-designware-master.c
index b47aa919b377..af8dd4017a2d 100644
--- a/drivers/i2c/busses/i2c-designware-master.c
+++ b/drivers/i2c/busses/i2c-designware-master.c
@@ -49,6 +49,7 @@ static void i2c_dw_set_timings_master(struct
dw_i2c_dev *dev)
{
u32 comp_param1;
u32 sda_falling_time, scl_falling_time;
+ const char *mode_str;
int ret = 0;
ret = i2c_dw_acquire_lock(dev);
@@ -133,6 +134,21 @@ static void i2c_dw_set_timings_master(struct
dw_i2c_dev *dev)
}
i2c_dw_set_sda_hold(dev);
+
+ switch (dev->master_cfg & DW_IC_CON_SPEED_MASK) {
+ case DW_IC_CON_SPEED_STD:
+ mode_str = "Standard Mode";
+ break;
+ case DW_IC_CON_SPEED_HIGH:
+ mode_str = "High Speed Mode";
+ break;
+ default:
+ if (dev->clk_freq == 1000000)
+ mode_str = "Fast Mode Plus";
+ else
+ mode_str = "Fast Mode";
I don't remember the style used for these modes elsewhere in the driver,
though here it feels like switch-case would be more suitable.
HW has only three modes (standard, fast/fm+ and high speed) and only
difference between fast mode and fast mode plus are the timing parameter
values. That's the reason for if statement inside the default case here.
--
Jarkko
