Messages in this thread | | | Date | Thu, 20 Aug 2020 13:52:55 +0300 | From | Andy Shevchenko <> | Subject | Re: [PATCH v8 2/2] Add PWM fan controller driver for LGM SoC |
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On Thu, Aug 20, 2020 at 12:50:46PM +0800, Rahul Tanwar wrote: > Intel Lightning Mountain(LGM) SoC contains a PWM fan controller. > This PWM controller does not have any other consumer, it is a > dedicated PWM controller for fan attached to the system. Add > driver for this PWM fan controller.
...
> +config PWM_INTEL_LGM > + tristate "Intel LGM PWM support"
> + depends on OF && HAS_IOMEM > + depends on X86 || COMPILE_TEST
For better test coverage you may rewrite this
depends on HAS_IOMEM depends on (OF && X86) || COMPILE_TEST
> + select REGMAP_MMIO > + help > + Generic PWM fan controller driver for LGM SoC. > + > + To compile this driver as a module, choose M here: the module > + will be called pwm-intel-lgm.
...
> +#include <linux/bitfield.h> > +#include <linux/clk.h> > +#include <linux/module.h>
> +#include <linux/of_device.h>
This should be mod_devicetable.h.
> +#include <linux/pwm.h> > +#include <linux/regmap.h> > +#include <linux/reset.h>
...
> +#define LGM_PWM_PERIOD_2WIRE_NSECS 40000000
NSECS -> NS 40000000 -> (40 * NSEC_PER_MSEC)
...
> + if (state->polarity != PWM_POLARITY_NORMAL || > + state->period < pc->period)
It can be one line.
> + return -EINVAL;
...
> + if (!state->enabled) {
> + ret = lgm_pwm_enable(chip, 0); > + return ret;
What is the point?
> + }
...
> + ret = lgm_pwm_enable(chip, 1); > + > + return ret;
Ditto.
...
> + state->duty_cycle = DIV_ROUND_UP(duty * pc->period, > + LGM_PWM_MAX_DUTY_CYCLE);
One line?
...
> + struct lgm_pwm_chip *pc; > + struct device *dev = &pdev->dev;
Use reversed xmas tree order.
> + void __iomem *io_base; > + int ret;
...
> + pc->regmap = devm_regmap_init_mmio(dev, io_base, &lgm_pwm_regmap_config); > + if (IS_ERR(pc->regmap)) {
> + ret = PTR_ERR(pc->regmap); > + if (ret != -EPROBE_DEFER) > + dev_err(dev, "failed to init register map: %pe\n", > + pc->regmap); > + return ret;
dev_err_probe()
> + }
...
> + pc->clk = devm_clk_get(dev, NULL); > + if (IS_ERR(pc->clk)) { > + ret = PTR_ERR(pc->clk); > + if (ret != -EPROBE_DEFER) > + dev_err(dev, "failed to get clock: %pe\n", pc->clk); > + return ret;
Ditto.
> + } > + > + pc->rst = devm_reset_control_get_exclusive(dev, NULL); > + if (IS_ERR(pc->rst)) { > + ret = PTR_ERR(pc->rst); > + if (ret != -EPROBE_DEFER) > + dev_err(dev, "failed to get reset control: %pe\n", > + pc->rst); > + return ret;
Ditto.
> + } > + > + ret = reset_control_deassert(pc->rst); > + if (ret) { > + if (ret != -EPROBE_DEFER) > + dev_err(dev, "cannot deassert reset control: %pe\n", > + ERR_PTR(ret)); > + return ret;
Ditto.
> + }
...
> + ret = clk_prepare_enable(pc->clk);
Wrap it with devm_add_action_or_reset(). Same for reset_control_deassert(). You probably can even put them under one function.
> + if (ret) { > + dev_err(dev, "failed to enable clock\n"); > + reset_control_assert(pc->rst); > + return ret; > + }
...
> + ret = pwmchip_add(&pc->chip);
> + if (ret < 0) {
Does ' < 0' have any meaning?
> + dev_err(dev, "failed to add PWM chip: %pe\n", ERR_PTR(ret)); > + clk_disable_unprepare(pc->clk); > + reset_control_assert(pc->rst); > + return ret; > + }
...
> + ret = pwmchip_remove(&pc->chip); > + if (ret < 0)
Ditto.
> + return ret;
-- With Best Regards, Andy Shevchenko
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