Re: [PATCH v1 1/2] regulator: rtmv20: Adds support for Richtek RTMV20 load switch regulator

From: Mark Brown
Date: Thu Sep 24 2020 - 12:12:10 EST


On Thu, Sep 24, 2020 at 11:04:50PM +0800, cy_huang wrote:

> +static int rtmv20_apply_properties(struct rtmv20_priv *priv)
> +{
> + const struct {
> + int offset;
> + int len;
> + unsigned int reg;
> + unsigned int mask;
> + } props[] = {
> + PROP_REG_DECL(ld_pulse_delay, RTMV20_REG_PULSEDELAY, RTMV20_DELAY_MASK),

I can't help but feel that this looks like a register cache would be a
simpler way of achieving this.

> + switch (props[i].len) {
> + case RTMV20_2BYTE_ACCES:
> + case RTMV20_1BYTE_ACCES:

It feels like this should all be abstracted in the regmap with custom
reg_read() and reg_write() operations - or have two regmaps for the two
different register sizes. Having the register sizes and endianness
handling outside of regmap code seems like an abstraction failure.

> + /* If chip is not enabled, only kept the value, instead */
> + if (!priv->is_chip_enabled)
> + return 0;
> +
> + return regmap_update_bits(priv->regmap, rdev->desc->csel_reg, rdev->desc->csel_mask, sel);

This sort of stuff works a lot better with a register cache.

> +static int rtmv20_lsw_enable(struct regulator_dev *rdev)
> +{
> + struct rtmv20_priv *priv = rdev_get_drvdata(rdev);
> + int ret;
> +
> + gpiod_set_value(priv->enable_gpio, 1);
> + /* Wait for I2C can be accessed */
> + usleep_range(RTMV20_I2CRDY_TIMEUS, RTMV20_I2CRDY_TIMEUS + 100);
> +
> + /* If enable gpio from low to high, the whole registers will be reset, applied here */

Please keep to 80 columns.

> + ret = regmap_read(priv->regmap, RTMV20_REG_LDIRQ, &val);
> + if (ret) {
> + dev_err(priv->dev, "Failed to get irq flags\n");
> + return IRQ_NONE;
> + }
> +
> + if (val & OTPEVT_MASK)
> + regulator_notifier_call_chain(priv->rdev, REGULATOR_EVENT_OVER_TEMP, NULL);
> +
> + if (val & OCPEVT_MASK)
> + regulator_notifier_call_chain(priv->rdev, REGULATOR_EVENT_OVER_CURRENT, NULL);
> +
> + if (val & FAILEVT_MASK)
> + regulator_notifier_call_chain(priv->rdev, REGULATOR_EVENT_FAIL, NULL);
> +
> + return IRQ_HANDLED;
> +}

It looks like this is clear on read but shouln't there be at least some
display of unknown values?

> + /* After chip check, keep in shutdown mode for low quiescent current */
> + gpiod_set_value(priv->enable_gpio, 0);

Don't do this, the driver should not adjust the system state unless
explicitly told to do so - we don't know if any state changes are safe
on a given board.

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