> Am 06.09.2019 um 22:46 schrieb H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>: > > Hi, > >> Am 06.09.2019 um 05:01 schrieb Viresh Kumar <viresh.kumar@xxxxxxxxxx>: >> >> On 05-09-19, 07:32, Tony Lindgren wrote: >>> * H. Nikolaus Schaller <hns@xxxxxxxxxxxxx> [190904 08:54]: >>>> This adds code and tables to read the silicon revision and >>>> eFuse (speed binned / 720 MHz grade) bits for selecting >>>> opp-v2 table entries. >>>> >>>> Since these bits are not always part of the syscon register >>>> range (like for am33xx, am43, dra7), we add code to directly >>>> read the register values using ioremap() if syscon access fails. >>> >>> This is nice :) Seems to work for me based on a quick test >>> on at least omap36xx. >>> >>> Looks like n900 produces the following though: >>> >>> core: _opp_supported_by_regulators: OPP minuV: 1270000 maxuV: 1270000, not supported by regulator >>> cpu cpu0: _opp_add: OPP not supported by regulators (550000000) >> >> That's a DT thing I believe where the voltage doesn't fit what the >> regulator can support. > > I can confirm this on BeagleBoard C2: > > root@gta04:~# dmesg|fgrep -i opp > [ 2.347442] core: _opp_supported_by_regulators: OPP minuV: 1270000 maxuV: 1270000, not supported by regulator > [ 2.359222] cpu cpu0: _opp_add: OPP not supported by regulators (550000000) > [ 2.580993] omap2_set_init_voltage: unable to find boot up OPP for vdd_core > root@gta04:~# > >> >>> But presumably that can be further patched. > > Well, the opp-v1 table also has this voltage point: > > /* OMAP343x/OMAP35xx variants OPP1-5 */ > operating-points = < > /* kHz uV */ > 125000 975000 > 250000 1075000 > 500000 1200000 > 550000 1270000 > 600000 1350000 > >; > > > This is OPP4 which is recommended by OMAP3530 data sheet to be 1.27V +/- 5% > > Data sheet of tps65950 says > > • VDD1: 1.2-A, buck DC/DC converter (VOUT = 0.6 V to 1.45 V, in steps of 12.5 mV) > > This means 1270 mV is not a "step" and rejected by the twl4030 driver. > Maybe nobody did notice yet because the opp-v1 drivers did not warn... > > The closest value to 1.27V is 0.6V + 54 * 12.5mV is 1.275V > > So let's also change the OPP4 to 1275000 uV in the opp-v2 table. The OPP is now available. Only [ 2.569519] omap2_set_init_voltage: unable to find boot up OPP for vdd_core remains but this is a different issue (mismatch between U-Boot clock/vdd_core setup and kernel table). Most likely U-Boot runs with an 300MHz OPP which is not defined by data sheet or kernel opp tables. BR, Nikolaus
