Re: [PATCH 01/12] soc: samsung: pmu: Use common device name to let others to find it easily

[Krzysztof Kozlowski <krzk@kernel.org>]

On Mon, Jan 16, 2017 at 07:44:56AM +0100, Marek Szyprowski wrote:
> This patch always set device name to "exynos-pmu" to let other drivers to
> find PMU device easily. This is done mainly to get regmap to access PMU
> registers from other drivers. This way it can be avoided to add phandle to
> the PMU node to almost all drivers in the SoC just to get a regmap access
> in the drivers. PMU is something like a SoC wide service, so there is no
> point modeling it as hardware dependency for all devices in device tree.
> 
> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
> ---
>  drivers/soc/samsung/exynos-pmu.c       |  1 +
>  include/linux/soc/samsung/exynos-pmu.h | 19 +++++++++++++++++++
>  2 files changed, 20 insertions(+)
> 
> diff --git a/drivers/soc/samsung/exynos-pmu.c b/drivers/soc/samsung/exynos-pmu.c
> index 0acdfd82e751..63bb471845cb 100644
> --- a/drivers/soc/samsung/exynos-pmu.c
> +++ b/drivers/soc/samsung/exynos-pmu.c
> @@ -120,6 +120,7 @@ static int exynos_pmu_probe(struct platform_device *pdev)
>  		pmu_context->pmu_data->pmu_init();
>  
>  	platform_set_drvdata(pdev, pmu_context);
> +	dev_set_name(dev, EXYNOS_PMU_DEV_NAME);
>  
>  	dev_dbg(dev, "Exynos PMU Driver probe done\n");
>  	return 0;
> diff --git a/include/linux/soc/samsung/exynos-pmu.h b/include/linux/soc/samsung/exynos-pmu.h
> index e2e9de1acc5b..90d9205805ea 100644
> --- a/include/linux/soc/samsung/exynos-pmu.h
> +++ b/include/linux/soc/samsung/exynos-pmu.h
> @@ -12,6 +12,10 @@
>  #ifndef __LINUX_SOC_EXYNOS_PMU_H
>  #define __LINUX_SOC_EXYNOS_PMU_H
>  
> +#include <linux/mfd/syscon.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +
>  enum sys_powerdown {
>  	SYS_AFTR,
>  	SYS_LPA,
> @@ -21,4 +25,19 @@ enum sys_powerdown {
>  
>  extern void exynos_sys_powerdown_conf(enum sys_powerdown mode);
>  
> +#define EXYNOS_PMU_DEV_NAME "exynos-pmu"

The define is not used outside so it should not be defined in header.
You need it only for the code below (see next comment).

> +
> +static inline struct regmap *exynos_get_pmu_regs(void)
> +{
> +	struct device *dev = bus_find_device_by_name(&platform_bus_type, NULL,
> +						     EXYNOS_PMU_DEV_NAME);
> +	if (dev) {
> +		struct regmap *regs = syscon_node_to_regmap(dev->of_node);
> +		put_device(dev);
> +		if (!IS_ERR(regs))
> +			return regs;
> +	}
> +	return NULL;
> +}

Any particular reason why definion of this is in header? This rather
looks like candidate for EXPORTED_SYMBOL defined in .c (plus Kconfig
dependency).

Best regards,
Krzysztof

> +
>  #endif /* __LINUX_SOC_EXYNOS_PMU_H */
> -- 
> 1.9.1
>