On Sat, Jun 27, 2020 at 10:17:38AM +0200, Andreas Kemnade wrote: > On Sun, 21 Jun 2020 00:42:15 +0200 > Jonathan Neuschäfer <j.neuschaefer@xxxxxxx> wrote: > > > Third-party hardware documentation is available at > > https://github.com/neuschaefer/linux/wiki/Netronix-MSP430-embedded-controller > > > > The EC supports interrupts, but the driver doesn't make use of them so > > far. > > > > Known problems: > > - The reboot handler is installed in such a way that it directly calls > > into the i2c subsystem to send the reboot command to the EC. This > > means that the reboot handler may sleep, which is not allowed. > > > see > https://patchwork.ozlabs.org/project/linux-i2c/patch/20190415213432.8972-3-contact@xxxxxxxxxxxxxxx/ > > for a fix of such problems. So far, regmap isn't involved here, but I'll remember it when I switch to regmap. Between when I first wrote this driver and now, the I2C has added support for transfers in atomic contexts very late in the system's life (exactly what happens when you reset a system via PMIC/EC), so this problem seems to be gone from my driver, for now. (See commit 63b96983a5ddf ("i2c: core: introduce callbacks for atomic transfers")) [...] > > +int ntxec_write8(struct ntxec *ec, u8 addr, u8 value) > > +{ > > + return ntxec_write16(ec, addr, value << 8); > > +} > > +EXPORT_SYMBOL(ntxec_write8); > > + > > do we really need both 16bit and 8bit accessors? No, the hardware/firmware doesn't care. > If not, then simply use regmap_i2c_init and set val_bits accordingly. > Maybe just doing the << 8 in the constants? Thanks, I'll try this approach. The values are not always constants, for example in the PWM driver: res |= ntxec_write8(pwm->ec, NTXEC_PERIOD_HIGH, period >> 8); res |= ntxec_write8(pwm->ec, NTXEC_PERIOD_LOW, period); res |= ntxec_write8(pwm->ec, NTXEC_DUTY_HIGH, duty >> 8); res |= ntxec_write8(pwm->ec, NTXEC_DUTY_LOW, duty); Jonathan
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