Hello, Thank you for the review of patches. 2014-10-31 10:42 GMT+03:00 Linus Walleij <linus.walleij@xxxxxxxxxx>: > On Tue, Oct 28, 2014 at 1:01 AM, Dmitry Eremin-Solenikov > <dbaryshkov@xxxxxxxxx> wrote: > >> LoCoMo is a GA used on Sharp Zaurus SL-5x00. Current driver does has >> several design issues (special bus instead of platform bus, doesn't use >> mfd-core, etc). >> >> Implement 'core' parts of locomo support as an mfd driver. >> >> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@xxxxxxxxx> > (...) > >> +/* DAC send data */ >> +#define M62332_SLAVE_ADDR 0x4e /* Slave address */ >> +#define M62332_W_BIT 0x00 /* W bit (0 only) */ >> +#define M62332_SUB_ADDR 0x00 /* Sub address */ >> +#define M62332_A_BIT 0x00 /* A bit (0 only) */ >> + >> +/* DAC setup and hold times (expressed in us) */ >> +#define DAC_BUS_FREE_TIME 5 /* 4.7 us */ >> +#define DAC_START_SETUP_TIME 5 /* 4.7 us */ >> +#define DAC_STOP_SETUP_TIME 4 /* 4.0 us */ >> +#define DAC_START_HOLD_TIME 5 /* 4.7 us */ >> +#define DAC_SCL_LOW_HOLD_TIME 5 /* 4.7 us */ >> +#define DAC_SCL_HIGH_HOLD_TIME 4 /* 4.0 us */ >> +#define DAC_DATA_SETUP_TIME 1 /* 250 ns */ >> +#define DAC_DATA_HOLD_TIME 1 /* 300 ns */ >> +#define DAC_LOW_SETUP_TIME 1 /* 300 ns */ >> +#define DAC_HIGH_SETUP_TIME 1 /* 1000 ns */ > (...) > > It seems some DAC handling is part of the MFD driver, and we recently > discussed that MFD should not be doing misc stuff but mainly act as > arbiter and switching station. > > Can you please move the DAC parts of the driver to > drivers/iio/dac? > > The IIO DAC subsystem will likely add other goodies to > the driver for free and give a nice API to consumers. I wanted this part to be as simple as possible. I will look into IIO DAC subsystem. The DAC is as simple 2 channel 8-bit i2c device connected to a separate i2c bus controlled through a register in LoCoMo device. One channel is used for backlight, other will be used for volume control. So (in theory) I can add the following device chain: locomo -> i2c-locomo -> m62332 -> IIO DAC client. However isn't that quite an overkill for just backlight & volume control? Please advice me on this. [skipped the irqdomain part - I will use them, thanks for the suggestion.] >> + /* Longtime timer */ >> + writew(0, lchip->base + LOCOMO_LTINT); >> + /* SPI */ >> + writew(0, lchip->base + LOCOMO_SPI + LOCOMO_SPIIE); >> + >> + writew(6 + 8 + 320 + 30 - 10, lchip->base + LOCOMO_ASD); > > That's a few magic numbers and calculation don't you think? > > A comment stating what's going on would be helpful. Unfortunately little is known here - these values are c&p from old 2.4 Lineo code. This part is related to generating synchronization pulses for accessing touchscreen. -- With best wishes Dmitry -- To unsubscribe from this list: send the line "unsubscribe linux-input" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
