Re: [PATCH v13 2/2] pwm: Add support for Xilinx AXI Timer

[Uwe Kleine-König]

Hello,

just a few minor things left for me to criticise:

On Fri, Feb 04, 2022 at 01:01:06PM -0500, Sean Anderson wrote:
> [...]
> +	regmap_read(priv->map, TCSR1, &tcsr1);
> +	state->period = xilinx_timer_get_period(priv, tlr0, tcsr0);
> +	state->duty_cycle = xilinx_timer_get_period(priv, tlr1, tcsr1);
> +	state->enabled = xilinx_timer_pwm_enabled(tcsr0, tcsr1);
> +	state->polarity = PWM_POLARITY_NORMAL;
> +
> +	/*
> +	 * 100% duty cycle results in constant low output. This may be slightly
> +	 * wrong if rate >= 1GHz, so fix this if you have such hardware :)
> +	 */

I'd drop "slightly" here. If the bug happens (e.g. tlr0 = 999999999,
tlr1 = 999999998, clkrate = 1000000001 Hz) then you diagnose a nearly
100% relative duty cycle as 0%. Also s/>= 1GHz/> 1 GHz/.

> [...]
> +	if (one_timer)
> +		return dev_err_probe(dev, -EINVAL,
> +				     "Two timers required for PWM mode\n");
> +
> +

One empty line here would be enough.

> diff --git a/include/clocksource/timer-xilinx.h b/include/clocksource/timer-xilinx.h
> new file mode 100644
> index 000000000000..1f7757b84a5e
> --- /dev/null
> +++ b/include/clocksource/timer-xilinx.h
> @@ -0,0 +1,91 @@
> [...]
> +/**
> + * xilinx_timer_common_init() - Perform common initialization for Xilinx
> + *                              AXI timer drivers.
> + * @priv: The timer's private data
> + * @np: The devicetree node for the timer
> + * @one_timer: Set to %1 if there is only one timer
> + *
> + * This performs common initialization, such as detecting endianness,
> + * and parsing devicetree properties. @priv->regs must be initialized
> + * before calling this function. This function initializes @priv->read,
> + * @priv->write, and @priv->width.
> + *
> + * Return: 0, or negative errno
> + */
> +int xilinx_timer_common_init(struct device_node *np,
> +			     struct xilinx_timer_priv *priv,
> +			     u32 *one_timer);

This function is gone, so the prototype should go away, too.

Best regards
Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-König            |
Industrial Linux Solutions                 | https://www.pengutronix.de/ |

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