Re: [PATCH v10 2/2] Add PWM fan controller driver for LGM SoC
From: Andy Shevchenko <hidden>
Date: 2020-08-24 08:17:23
Also in:
linux-pwm, lkml
On Mon, Aug 24, 2020 at 11:36:37AM +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.
...
+ 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_probe(dev, ret, "failed to init register map\n");
+ return ret;
+ }
+
+ pc->clk = devm_clk_get(dev, NULL);
+ if (IS_ERR(pc->clk)) {
+ ret = PTR_ERR(pc->clk);
+ if (ret != -EPROBE_DEFER)
+ dev_err_probe(dev, ret, "failed to get clock\n");
+ return ret;
+ }
+
+ 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_probe(dev, ret, "failed to get reset control\n");
+ return ret;
+ }
+
+ ret = reset_control_deassert(pc->rst);
+ if (ret) {
+ if (ret != -EPROBE_DEFER)
+ dev_err_probe(dev, ret, "cannot deassert reset control\n");
+ return ret;
+ }Please, spend a bit of time to understand the changes you are doing. There are already few examples how to use dev_err_probe() properly.
+ ret = clk_prepare_enable(pc->clk);
+ if (ret) {
+ dev_err(dev, "failed to enable clock\n");
+ return ret;
+ }
+
+ ret = devm_add_action_or_reset(dev, lgm_pwm_action, pc);
+ if (ret)
+ return ret;
You have also ordering issues here.
So, what I can see about implementation is that
static void ..._clk_disable(void *data)
{
clk_disable_unprepare(data);
}
static int ..._clk_enable(...)
{
int ret;
ret = clk_preare_enable(...);
if (ret)
return ret;
return devm_add_action_or_reset(..., ..._clk_disable);
}
Similar for reset control.
Then in the ->probe() something like this:
ret = devm_reset_control_get...;
if (ret)
return ret;
ret = ..._reset_deassert(...);
if (ret)
return ret;
followed by similar section for the clock.
--
With Best Regards,
Andy Shevchenko