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[v4,0/2] Add regmap support to exynos-pmu for protected PMU regs

Message ID 20240208161700.268570-1-peter.griffin@linaro.org
Headers show
Series Add regmap support to exynos-pmu for protected PMU regs | expand

Message

Peter Griffin Feb. 8, 2024, 4:16 p.m. UTC
Hi folks,

This is a v4 of the series to add support for protected PMU registers found
on gs101 and derivative SoCs. In v2 and later it was re-worked to be based
on a regmap abstraction that I think leads to a much neater overall
solution.

The advantage of the regmap abstraction is that most leaf drivers that
read/write PMU registers need minimal changes.

Example of Exynos drivers that require PMU register access are:
* watchdog
* usb phy
* mipi phy
* ufs phy

This series has been tested on Pixel 6 / gs101. If the various maintainers/
contributors of other Exynos SoCs like exynos850, exynosautov9, exynos5422
etc can test these patches on your respective systems that would be most
appreciated.

The expectation is this series would be merged via Krzysztofs Samsung
Exynos tree.

regards,

Peter

Changes since v3:
 - Fix PMUALIVE_MASK
 - Add TENSOR_ prefix
 - clear SET_BITS bits on each loop iteration
 - change set_bit to set_bits func name
 - Fix some alignment
 - Add missing return on dev_err_probe
 - Reduce indentation in loop

Changes since v2
 - Add select REGMAP to Kconfig
 - Add constant for SET/CLEAR bits
 - Replace kerneldoc with one line comment
 - Fix kerneldoc for EXPORT_SYMBOL_GPL funcs
 - remove superfluous extern keyword
 - dev_err_probe() on probe error
 - shorten regmcfg name
 - no compatibles inside probe, use match data
 - don't mix declarations with/without initializations
 - tensor_sec_reg_read() use mmio to avoid access restrictions
 - Collect up Reviewed-by
 - const for regmap_config structs

Changes since v1:
 - Refactor to use custom regmap to abstract SMC register access
   (Sam / Guenter)
 - Add deferred probing support (Saravana / Krzysztof)

v3 lore: https://lore.kernel.org/linux-arm-kernel/20240202145731.4082033-1-peter.griffin@linaro.org/
v2 lore: https://lore.kernel.org/lkml/20240129211912.3068411-1-peter.griffin@linaro.org/
v1 lore: https://lore.kernel.org/all/20240122225710.1952066-1-peter.griffin@linaro.org/

Peter Griffin (2):
  soc: samsung: exynos-pmu: Add regmap support for SoCs that protect PMU
    regs
  watchdog: s3c2410_wdt: use exynos_get_pmu_regmap_by_phandle() for PMU
    regs

 drivers/soc/samsung/Kconfig            |   1 +
 drivers/soc/samsung/exynos-pmu.c       | 235 ++++++++++++++++++++++++-
 drivers/soc/samsung/exynos-pmu.h       |   1 +
 drivers/watchdog/Kconfig               |   1 -
 drivers/watchdog/s3c2410_wdt.c         |   8 +-
 include/linux/soc/samsung/exynos-pmu.h |  11 +-
 6 files changed, 247 insertions(+), 10 deletions(-)

Comments

Guenter Roeck Feb. 8, 2024, 5:38 p.m. UTC | #1
On 2/8/24 08:17, Peter Griffin wrote:
> Obtain the PMU regmap using the new API added to exynos-pmu driver rather
> than syscon_regmap_lookup_by_phandle(). As this driver no longer depends
> on mfd syscon remove that header and Kconfig dependency.
> 
> Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
> Signed-off-by: Peter Griffin <peter.griffin@linaro.org>

Acked-by: Guenter Roeck <linux@roeck-us.net>

> ---
>   drivers/watchdog/Kconfig       | 1 -
>   drivers/watchdog/s3c2410_wdt.c | 8 ++++----
>   2 files changed, 4 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 7d22051b15a2..d78fe7137799 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -512,7 +512,6 @@ config S3C2410_WATCHDOG
>   	tristate "S3C6410/S5Pv210/Exynos Watchdog"
>   	depends on ARCH_S3C64XX || ARCH_S5PV210 || ARCH_EXYNOS || COMPILE_TEST
>   	select WATCHDOG_CORE
> -	select MFD_SYSCON if ARCH_EXYNOS
>   	help
>   	  Watchdog timer block in the Samsung S3C64xx, S5Pv210 and Exynos
>   	  SoCs. This will reboot the system when the timer expires with
> diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
> index 349d30462c8c..686cf544d0ae 100644
> --- a/drivers/watchdog/s3c2410_wdt.c
> +++ b/drivers/watchdog/s3c2410_wdt.c
> @@ -24,9 +24,9 @@
>   #include <linux/slab.h>
>   #include <linux/err.h>
>   #include <linux/of.h>
> -#include <linux/mfd/syscon.h>
>   #include <linux/regmap.h>
>   #include <linux/delay.h>
> +#include <linux/soc/samsung/exynos-pmu.h>
>   
>   #define S3C2410_WTCON		0x00
>   #define S3C2410_WTDAT		0x04
> @@ -699,11 +699,11 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>   		return ret;
>   
>   	if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) {
> -		wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
> -						"samsung,syscon-phandle");
> +		wdt->pmureg = exynos_get_pmu_regmap_by_phandle(dev->of_node,
> +						 "samsung,syscon-phandle");
>   		if (IS_ERR(wdt->pmureg))
>   			return dev_err_probe(dev, PTR_ERR(wdt->pmureg),
> -					     "syscon regmap lookup failed.\n");
> +					     "PMU regmap lookup failed.\n");
>   	}
>   
>   	wdt_irq = platform_get_irq(pdev, 0);
Alexey Klimov Feb. 9, 2024, 10:35 a.m. UTC | #2
On Thu, 8 Feb 2024 at 16:21, Peter Griffin <peter.griffin@linaro.org> wrote:
>
> Obtain the PMU regmap using the new API added to exynos-pmu driver rather
> than syscon_regmap_lookup_by_phandle(). As this driver no longer depends
> on mfd syscon remove that header and Kconfig dependency.
>
> Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
> Signed-off-by: Peter Griffin <peter.griffin@linaro.org>

Tested-by: Alexey Klimov <alexey.klimov@linaro.org>

Tested on odroid xu3 (exynos5422). Watchdog works as expected and can
reset the system.

> ---
>  drivers/watchdog/Kconfig       | 1 -
>  drivers/watchdog/s3c2410_wdt.c | 8 ++++----
>  2 files changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig
> index 7d22051b15a2..d78fe7137799 100644
> --- a/drivers/watchdog/Kconfig
> +++ b/drivers/watchdog/Kconfig
> @@ -512,7 +512,6 @@ config S3C2410_WATCHDOG
>         tristate "S3C6410/S5Pv210/Exynos Watchdog"
>         depends on ARCH_S3C64XX || ARCH_S5PV210 || ARCH_EXYNOS || COMPILE_TEST
>         select WATCHDOG_CORE
> -       select MFD_SYSCON if ARCH_EXYNOS
>         help
>           Watchdog timer block in the Samsung S3C64xx, S5Pv210 and Exynos
>           SoCs. This will reboot the system when the timer expires with
> diff --git a/drivers/watchdog/s3c2410_wdt.c b/drivers/watchdog/s3c2410_wdt.c
> index 349d30462c8c..686cf544d0ae 100644
> --- a/drivers/watchdog/s3c2410_wdt.c
> +++ b/drivers/watchdog/s3c2410_wdt.c
> @@ -24,9 +24,9 @@
>  #include <linux/slab.h>
>  #include <linux/err.h>
>  #include <linux/of.h>
> -#include <linux/mfd/syscon.h>
>  #include <linux/regmap.h>
>  #include <linux/delay.h>
> +#include <linux/soc/samsung/exynos-pmu.h>
>
>  #define S3C2410_WTCON          0x00
>  #define S3C2410_WTDAT          0x04
> @@ -699,11 +699,11 @@ static int s3c2410wdt_probe(struct platform_device *pdev)
>                 return ret;
>
>         if (wdt->drv_data->quirks & QUIRKS_HAVE_PMUREG) {
> -               wdt->pmureg = syscon_regmap_lookup_by_phandle(dev->of_node,
> -                                               "samsung,syscon-phandle");
> +               wdt->pmureg = exynos_get_pmu_regmap_by_phandle(dev->of_node,
> +                                                "samsung,syscon-phandle");
>                 if (IS_ERR(wdt->pmureg))
>                         return dev_err_probe(dev, PTR_ERR(wdt->pmureg),
> -                                            "syscon regmap lookup failed.\n");
> +                                            "PMU regmap lookup failed.\n");
>         }
>
>         wdt_irq = platform_get_irq(pdev, 0);
> --
> 2.43.0.594.gd9cf4e227d-goog
>