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[4/6] soc: samsung: pm_domains: Implement proper I/O operations

Message ID 20230308230931.27261-5-semen.protsenko@linaro.org
State New
Headers show
Series soc: samsung: pm_domains: Add Exynos850 support | expand

Commit Message

Sam Protsenko March 8, 2023, 11:09 p.m. UTC
Instead of doing in-place readl()/writel() calls fed with magic numbers,
provide dedicated read/write functions which implement proper register
accesses:
  - Get rid of magic numbers by introducing actual constants for PD
    registers
  - Rework the write function to perform a RMW operation, as PD
    registers have some bits markes as "Reserved" in TRM, which
    shouldn't be changed
  - Add helper functions for reading the STATUS reg and writing
    CONFIGURATION reg, to make user code more neat and clean

New functions are designed in such a way that it's easy to rework those
further on top of regmap API.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
---
 drivers/soc/samsung/pm_domains.c | 42 +++++++++++++++++++++++++++++---
 1 file changed, 38 insertions(+), 4 deletions(-)

Comments

kernel test robot March 9, 2023, 12:45 a.m. UTC | #1
Hi Sam,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on krzk/for-next]
[also build test WARNING on robh/for-next krzk-dt/for-next linus/master v6.3-rc1 next-20230308]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Sam-Protsenko/dt-bindings-power-pd-samsung-Add-Exynos850-support/20230309-071202
base:   https://git.kernel.org/pub/scm/linux/kernel/git/krzk/linux.git for-next
patch link:    https://lore.kernel.org/r/20230308230931.27261-5-semen.protsenko%40linaro.org
patch subject: [PATCH 4/6] soc: samsung: pm_domains: Implement proper I/O operations
config: m68k-allyesconfig (https://download.01.org/0day-ci/archive/20230309/202303090824.TjEOnQJ8-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 12.1.0
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # https://github.com/intel-lab-lkp/linux/commit/2dabd70f9264ef6cd044de6c3cbd3d83bfef8442
        git remote add linux-review https://github.com/intel-lab-lkp/linux
        git fetch --no-tags linux-review Sam-Protsenko/dt-bindings-power-pd-samsung-Add-Exynos850-support/20230309-071202
        git checkout 2dabd70f9264ef6cd044de6c3cbd3d83bfef8442
        # save the config file
        mkdir build_dir && cp config build_dir/.config
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k olddefconfig
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-12.1.0 make.cross W=1 O=build_dir ARCH=m68k SHELL=/bin/bash drivers/soc/samsung/

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202303090824.TjEOnQJ8-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/soc/samsung/pm_domains.c: In function 'exynos_pd_power':
>> drivers/soc/samsung/pm_domains.c:74:23: warning: variable 'base' set but not used [-Wunused-but-set-variable]
      74 |         void __iomem *base;
         |                       ^~~~


vim +/base +74 drivers/soc/samsung/pm_domains.c

2dabd70f9264ef drivers/soc/samsung/pm_domains.c  Sam Protsenko       2023-03-08   70  
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   71  static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on)
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   72  {
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   73  	struct exynos_pm_domain *pd;
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27  @74  	void __iomem *base;
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   75  	u32 timeout, pwr;
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   76  	char *op;
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   77  
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   78  	pd = container_of(domain, struct exynos_pm_domain, pd);
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   79  	base = pd->base;
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   80  
c028e175713698 drivers/soc/samsung/pm_domains.c  Krzysztof Kozlowski 2016-05-10   81  	pwr = power_on ? pd->local_pwr_cfg : 0;
2dabd70f9264ef drivers/soc/samsung/pm_domains.c  Sam Protsenko       2023-03-08   82  	exynos_pd_write_conf(pd, pwr);
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   83  
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   84  	/* Wait max 1ms */
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   85  	timeout = 10;
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   86  
2dabd70f9264ef drivers/soc/samsung/pm_domains.c  Sam Protsenko       2023-03-08   87  	while (exynos_pd_read_status(pd) != pwr) {
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   88  		if (!timeout) {
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   89  			op = (power_on) ? "enable" : "disable";
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   90  			pr_err("Power domain %s %s failed\n", domain->name, op);
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   91  			return -ETIMEDOUT;
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   92  		}
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   93  		timeout--;
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   94  		cpu_relax();
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   95  		usleep_range(80, 100);
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   96  	}
c760569d0e9c06 arch/arm/mach-exynos/pm_domains.c Prathyush K         2014-07-11   97  
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   98  	return 0;
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27   99  }
91cfbd4ee0875f arch/arm/mach-exynos/pm_domains.c Thomas Abraham      2012-01-27  100
diff mbox series

Patch

diff --git a/drivers/soc/samsung/pm_domains.c b/drivers/soc/samsung/pm_domains.c
index 522a43005a5a..dd1ec3541e11 100644
--- a/drivers/soc/samsung/pm_domains.c
+++ b/drivers/soc/samsung/pm_domains.c
@@ -18,6 +18,10 @@ 
 #include <linux/of_platform.h>
 #include <linux/pm_runtime.h>
 
+/* Register offsets inside Power Domain area in PMU */
+#define EXYNOS_PD_CONF		0x0
+#define EXYNOS_PD_STATUS	0x4
+
 struct exynos_pm_domain_config {
 	/* Value for LOCAL_PWR_CFG and STATUS fields for each domain */
 	u32 local_pwr_cfg;
@@ -33,6 +37,37 @@  struct exynos_pm_domain {
 	u32 local_pwr_cfg;
 };
 
+static void exynos_pd_write(struct exynos_pm_domain *pd, unsigned int reg,
+			    unsigned int mask, unsigned int val)
+{
+	u32 v;
+
+	v = readl_relaxed(pd->base + reg);
+	v = (v & ~mask) | val;
+	writel_relaxed(v, pd->base + reg);
+}
+
+static void exynos_pd_read(struct exynos_pm_domain *pd, unsigned int reg,
+			   unsigned int *val)
+{
+	*val = readl_relaxed(pd->base + reg);
+}
+
+static unsigned int exynos_pd_read_status(struct exynos_pm_domain *pd)
+{
+	unsigned int val;
+
+	exynos_pd_read(pd, EXYNOS_PD_STATUS, &val);
+	val &= pd->local_pwr_cfg;
+
+	return val;
+}
+
+static void exynos_pd_write_conf(struct exynos_pm_domain *pd, u32 val)
+{
+	exynos_pd_write(pd, EXYNOS_PD_CONF, pd->local_pwr_cfg, val);
+}
+
 static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on)
 {
 	struct exynos_pm_domain *pd;
@@ -44,12 +79,12 @@  static int exynos_pd_power(struct generic_pm_domain *domain, bool power_on)
 	base = pd->base;
 
 	pwr = power_on ? pd->local_pwr_cfg : 0;
-	writel_relaxed(pwr, base);
+	exynos_pd_write_conf(pd, pwr);
 
 	/* Wait max 1ms */
 	timeout = 10;
 
-	while ((readl_relaxed(base + 0x4) & pd->local_pwr_cfg) != pwr) {
+	while (exynos_pd_read_status(pd) != pwr) {
 		if (!timeout) {
 			op = (power_on) ? "enable" : "disable";
 			pr_err("Power domain %s %s failed\n", domain->name, op);
@@ -135,8 +170,7 @@  static int exynos_pd_probe(struct platform_device *pdev)
 	pd->pd.power_off = exynos_pd_power_off;
 	pd->pd.power_on = exynos_pd_power_on;
 
-	on = readl_relaxed(pd->base + 0x4) & pd->local_pwr_cfg;
-
+	on = exynos_pd_read_status(pd);
 	pm_genpd_init(&pd->pd, NULL, !on);
 	ret = of_genpd_add_provider_simple(np, &pd->pd);