Dear Rob, On Thu, 7 Apr 2016 12:57:59 -0500 Rob Herring wrote: > On Wed, Apr 06, 2016 at 03:28:00PM +0800, Jisheng Zhang wrote: > > Sometimes, it's convenient to define the scl's high/low count directly, > > e.g HW people would do some measurement then directly give out the > > optimum counts. Previously, we solved the sda falling time and scl > > falling time by i2c_dw_scl_hcnt() and i2c_dw_scl_lcnt(), then put them > > into dt, but what we really care isn't the sda/scl falling time. > > This is just so you can put specific clock count instead of converting > from nanoseconds with standard properties or you gain some additional > control of the timing. If only the former, then I prefer we stick with > the common properties. To be honest, both. Let me show how I gain additional control of the timing with this patch while I can't do this w/o it. I want the similar high percent of SCL high for both standard-mode and fast-mode. Before this patch, this is not achievable because the parameters to cal the hcnt/lcnt via i2c_dw_scl_hcnt() and i2c_dw_scl_lcnt() are different for standard-mode and fast-mode. Thanks, Jisheng > > > From another side, the dw_i2c_acpi_configure() on ACPI platform also > > get hcnt/lcnt values rather than the sda/scl falling time from ACPI > > method, we want similar feature for DT platforms. > > That's nice, but not really a reason IMO. > > > > > Signed-off-by: Jisheng Zhang <jszhang@xxxxxxxxxxx> > > --- > > Documentation/devicetree/bindings/i2c/i2c-designware.txt | 16 ++++++++++++++++ > > drivers/i2c/busses/i2c-designware-platdrv.c | 8 ++++++++ > > 2 files changed, 24 insertions(+) -- 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
