On Fri, Feb 14, 2025 at 12:49:53PM +0100, mathieu.dubois-briand@xxxxxxxxxxx wrote:
> From: Kamel Bouhara <kamel.bouhara@xxxxxxxxxxx>
>
> Add driver for Maxim Integrated MAX7360 PWM controller, supporting up to
> 8 independent PWM outputs.
...
+ bits.h
+ dev_printk.h
> +#include <linux/err.h>
> +#include <linux/math.h>
Other way around, id est you need math64.h (see below).
> +#include <linux/mfd/max7360.h>
+ minmax.h
> +#include <linux/mod_devicetable.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
Is this used? Cargo cult?
> +#include <linux/platform_device.h>
> +#include <linux/pwm.h>
> +#include <linux/regmap.h>
+ types.h
...
> +#define MAX7360_PWM_PERIOD_NS 2000000 /* 500 Hz */
Comment is superfluous, if you need HZ units, define the respective one.
Also you can use something like (2 * NSEC_PER_MSEC) which will immediately
gives a hint of how long this is and reduces potential 0:s miscalculations.
This will need time.h
...
> +#define MAX7360_PWM_CTRL_ENABLE(n) BIT(n)
> +#define MAX7360_PWM_PORT(n) BIT(n)
Personally I find these macros overkill. The value of them much shorter and
equally readable.
...
> +struct max7360_pwm {
> + struct device *parent;
Is it not the same as you can derive from regmap?
> + struct regmap *regmap;
Btw, have you checked the code generation if you place regmap the first in the
structure? It might affect it.
> +};
...
> + /*
> + * Ignore user provided values for period_length_ns and duty_offset_ns:
> + * we only support fixed period of MAX7360_PWM_PERIOD_NS and offset of
> + * 0.
Easy to read with 0 be on previous line.
> + */
> +
No need for this blank line.
> + duty_steps = mul_u64_u64_div_u64(wf->duty_length_ns, MAX7360_PWM_MAX_RES,
> + MAX7360_PWM_PERIOD_NS);
This comes from math64.h
> +
> + wfhw->duty_steps = min(MAX7360_PWM_MAX_RES, duty_steps);
...
> +static int max7360_pwm_write_waveform(struct pwm_chip *chip,
> + struct pwm_device *pwm,
> + const void *_wfhw)
> +{
> + const struct max7360_pwm_waveform *wfhw = _wfhw;
> + struct max7360_pwm *max7360_pwm;
> + unsigned int val;
> + int ret;
> +
> + max7360_pwm = max7360_pwm_from_chip(chip);
> +
> + val = (wfhw->duty_steps == 0) ? 0 : MAX7360_PWM_CTRL_ENABLE(pwm->hwpwm);
> + ret = regmap_write_bits(max7360_pwm->regmap, MAX7360_REG_GPIOCTRL,
> + MAX7360_PWM_CTRL_ENABLE(pwm->hwpwm), val);
> +
> + if (!ret && wfhw->duty_steps != 0) {
> + ret = regmap_write(max7360_pwm->regmap, MAX7360_REG_PWM(pwm->hwpwm),
> + wfhw->duty_steps);
> + }
> +
> + return ret;
Please, improve readability by rewriting like this:
ret = regmap_write_bits(max7360_pwm->regmap, MAX7360_REG_GPIOCTRL,
MAX7360_PWM_CTRL_ENABLE(pwm->hwpwm), val);
if (ret)
return ret;
if (wfhw->duty_steps)
return regmap_write(max7360_pwm->regmap, MAX7360_REG_PWM(pwm->hwpwm),
wfhw->duty_steps);
return 0;
> +}
...
> +static int max7360_pwm_probe(struct platform_device *pdev)
> +{
With
struct device *dev = &pdev->dev;
all below will look shorter and nicer.
> + struct max7360_pwm *max7360_pwm;
> + struct pwm_chip *chip;
> + int ret;
> +
> + if (!pdev->dev.parent)
> + return dev_err_probe(&pdev->dev, -ENODEV, "no parent device\n");
> +
> + chip = devm_pwmchip_alloc(pdev->dev.parent, MAX7360_NUM_PWMS,
> + sizeof(*max7360_pwm));
> + if (IS_ERR(chip))
> + return PTR_ERR(chip);
> + chip->ops = &max7360_pwm_ops;
> +
> + max7360_pwm = max7360_pwm_from_chip(chip);
> + max7360_pwm->parent = pdev->dev.parent;
> +
> + max7360_pwm->regmap = dev_get_regmap(pdev->dev.parent, NULL);
> + if (!max7360_pwm->regmap)
> + return dev_err_probe(&pdev->dev, -ENODEV,
> + "could not get parent regmap\n");
Will become one line (with the above suggestion).
> + ret = devm_pwmchip_add(&pdev->dev, chip);
> + if (ret != 0)
Please, be consistent with the style, and moreover this style is unusual.
> + return dev_err_probe(&pdev->dev, ret,
> + "failed to add PWM chip\n");
> +
> + return 0;
> +}
--
With Best Regards,
Andy Shevchenko
