[PATCH v1 2/2] hwmon: npcm-pwm: add NPCM7xx PWM driver

[kbuild test robot]

Hi Tomer,

I love your patch! Perhaps something to improve:

[auto build test WARNING on hwmon/hwmon-next]
[also build test WARNING on v4.17-rc7]
[if your patch is applied to the wrong git tree, please drop us a note to help improve the system]

url:    https://github.com/0day-ci/linux/commits/Tomer-Maimon/dt-binding-hwmon-Add-NPCM7xx-PWM-documentation/20180531-034040
base:   https://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging.git hwmon-next
config: x86_64-allmodconfig
compiler: gcc-7 (Debian 7.3.0-16) 7.3.0
reproduce:
        make ARCH=x86_64  allmodconfig
        make ARCH=x86_64 

All warnings (new ones prefixed by >>):


vim +277 drivers/hwmon/npcm7xx-pwm.c

   250	
   251	static int npcm7xx_pwm_probe(struct platform_device *pdev)
   252	{
   253		struct device *dev = &pdev->dev;
   254		struct npcm7xx_pwm_data *data;
   255		struct resource res[NPCM7XX_PWM_MAX_MODULES];
   256		struct device *hwmon;
   257		struct clk *clk;
   258		int m, ch, res_cnt, ret;
   259		u32 Prescale_val, output_freq;
   260	
   261		data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
   262		if (!data)
   263			return -ENOMEM;
   264	
   265		for (res_cnt = 0; res_cnt < NPCM7XX_PWM_MAX_MODULES  ; res_cnt++) {
   266			ret = of_address_to_resource(dev->of_node, res_cnt,
   267						     &res[res_cnt]);
   268			if (ret) {
   269				pr_err("PWM of_address_to_resource fail ret %d\n",
   270				       ret);
   271				return -EINVAL;
   272			}
   273	
   274			data->pwm_base[res_cnt] =
   275				devm_ioremap_resource(dev, &(res[res_cnt]));
 > 276			pr_debug("pwm%d base is 0x%08X, res.start 0x%08X , size 0x%08X\n",
 > 277				 res_cnt, (u32)data->pwm_base[res_cnt],
   278				 res[res_cnt].start, resource_size(&(res[res_cnt])));
   279	
   280			if (!data->pwm_base[res_cnt]) {
   281				pr_err("pwm probe failed: can't read pwm base address for resource %d.\n",
   282				       res_cnt);
   283				return -ENOMEM;
   284			}
   285	
   286			mutex_init(&data->npcm7xx_pwm_lock[res_cnt]);
   287		}
   288	
   289		clk = devm_clk_get(dev, NULL);
   290		if (IS_ERR(clk))
   291			return -ENODEV;
   292	
   293		data->clk_freq = clk_get_rate(clk);
   294	
   295		/* Adjust NPCM7xx PWMs output frequency to ~25Khz */
   296		output_freq = data->clk_freq / PWN_CNT_DEFAULT;
   297		Prescale_val = DIV_ROUND_CLOSEST(output_freq, PWM_OUTPUT_FREQ_25KHZ);
   298	
   299		/* If Prescale_val = 0, then the prescale output clock is stopped */
   300		if (Prescale_val < MIN_PRESCALE1)
   301			Prescale_val = MIN_PRESCALE1;
   302		/*
   303		 * Prescale_val need to decrement in one because in the PWM Prescale
   304		 * register the Prescale value increment by one
   305		 */
   306		Prescale_val--;
   307	
   308		/* Setting PWM Prescale Register value register to both modules */
   309		Prescale_val |= (Prescale_val << NPCM7XX_PWM_PRESCALE_SHIFT_CH01);
   310	
   311		for (m = 0; m < NPCM7XX_PWM_MAX_MODULES  ; m++) {
   312			iowrite32(Prescale_val,
   313				  data->pwm_base[m] + NPCM7XX_PWM_REG_PR);
   314			iowrite32(NPCM7XX_PWM_PRESCALE2_DEFALUT,
   315				  data->pwm_base[m] + NPCM7XX_PWM_REG_CSR);
   316			iowrite32(NPCM7XX_PWM_CTRL_MODE_DEFALUT,
   317				  data->pwm_base[m] + NPCM7XX_PWM_REG_CR);
   318	
   319			for (ch = 0; ch < NPCM7XX_PWM_MAX_CHN_NUM; ch++) {
   320				iowrite32(NPCM7XX_PWM_COUNTER_DEFALUT_NUM,
   321					  data->pwm_base[m] + NPCM7XX_PWM_REG_CNRx(ch));
   322				iowrite32(NPCM7XX_PWM_COMPARATOR_DEFALUT_NUM,
   323					  data->pwm_base[m] + NPCM7XX_PWM_REG_CMRx(ch));
   324			}
   325	
   326			iowrite32(NPCM7XX_PWM_CTRL_MODE_DEFALUT |
   327				  NPCM7XX_PWM_CTRL_EN_DEFALUT,
   328				  data->pwm_base[m] + NPCM7XX_PWM_REG_CR);
   329		}
   330	
   331		hwmon = devm_hwmon_device_register_with_info(dev, "npcm7xx_pwm", data,
   332							     &npcm7xx_chip_info, NULL);
   333	
   334		if (IS_ERR(hwmon)) {
   335			pr_err("PWM Driver failed - devm_hwmon_device_register_with_groups failed\n");
   336			return PTR_ERR(hwmon);
   337		}
   338	
   339		pr_info("NPCM7XX PWM Driver probed, PWM output Freq %dHz\n",
   340			output_freq / ((Prescale_val & 0xf) + 1));
   341	
   342		return 0;
   343	}
   344	

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