[PATCH 4/4] cpufreq: imx6q: check regulator_get_optional return value

[l.stach@pengutronix.de (Lucas Stach)]

Am Donnerstag, den 22.10.2015, 10:47 +0200 schrieb Sascha Hauer:
> While pu_reg is an optional regulator we still have to check
> the return value for -EPROBE_DEFER to properly detect the
> case when we have a pu regulator but it is not yet present.
> 
> While at it, set pu_reg to NULL for an erroneous regulator
> so that we can check for the regulator with if (pu_reg)
> instead of the slightly less readable IS_ERR().
> 
> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
> ---
>  drivers/cpufreq/imx6q-cpufreq.c | 11 ++++++++---
>  1 file changed, 8 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
> index ce0c6bd..b643614 100644
> --- a/drivers/cpufreq/imx6q-cpufreq.c
> +++ b/drivers/cpufreq/imx6q-cpufreq.c
> @@ -71,7 +71,7 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
>  
>  	/* scaling up?  scale voltage before frequency */
>  	if (new_freq > old_freq) {
> -		if (!IS_ERR(pu_reg)) {
> +		if (pu_reg) {
>  			ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
>  			if (ret) {
>  				dev_err(cpu_dev, "failed to scale vddpu up: %d\n", ret);
> @@ -148,7 +148,7 @@ static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
>  			dev_warn(cpu_dev, "failed to scale vddsoc down: %d\n", ret);
>  			ret = 0;
>  		}
> -		if (!IS_ERR(pu_reg)) {
> +		if (pu_reg) {
>  			ret = regulator_set_voltage_tol(pu_reg, imx6_soc_volt[index], 0);
>  			if (ret) {
>  				dev_warn(cpu_dev, "failed to scale vddpu down: %d\n", ret);
> @@ -217,6 +217,11 @@ static int imx6q_cpufreq_get_resources(struct platform_device *pdev)
>  		return PTR_ERR(arm_reg);
>  
>  	pu_reg = regulator_get_optional(cpu_dev, "pu");
> +	if (IS_ERR(pu_reg)) {
> +		if (PTR_ERR(pu_reg) == -EPROBE_DEFER)
> +			return -EPROBE_DEFER;
> +		pu_reg = NULL;
> +	}

The PU regulator isn't really optional for MX6 Q/DL (where it is present
in hardware) as the datasheet clearly specifies that it needs to be set
to the same voltage as SOC. Could you change this to request this
regulator as non-optional for those chip derivatives and skip the
request otherwise?

Regards,
Lucas

>  
>  	soc_reg = regulator_get(cpu_dev, "soc");
>  	if (IS_ERR(soc_reg))
> @@ -377,7 +382,7 @@ soc_opp_out:
>  	ret = regulator_set_voltage_time(soc_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
>  	if (ret > 0)
>  		transition_latency += ret * 1000;
> -	if (!IS_ERR(pu_reg)) {
> +	if (pu_reg) {
>  		ret = regulator_set_voltage_time(pu_reg, imx6_soc_volt[0], imx6_soc_volt[num - 1]);
>  		if (ret > 0)
>  			transition_latency += ret * 1000;

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