More comments after Russell's reply. On 19-05-18, 14:35, Ilia Lin wrote: > +static int __init qcom_cpufreq_kryo_driver_init(void) > +{ > + struct device *cpu_dev_silver, *cpu_dev_gold; > + struct opp_table *opp_silver, *opp_gold; > + enum _msm8996_version msm8996_version; > + struct nvmem_cell *speedbin_nvmem; > + struct platform_device *pdev; > + struct device_node *np; > + u8 *speedbin; > + u32 versions; > + size_t len; > + int ret; > + > + cpu_dev_silver = get_cpu_device(SILVER_LEAD); > + if (IS_ERR_OR_NULL(cpu_dev_silver)) get_cpu_device() returns only NULL on error. > + return PTR_ERR(cpu_dev_silver); > + > + cpu_dev_gold = get_cpu_device(SILVER_LEAD); > + if (IS_ERR_OR_NULL(cpu_dev_gold)) > + return PTR_ERR(cpu_dev_gold); > + > + msm8996_version = qcom_cpufreq_kryo_get_msm_id(); > + if (NUM_OF_MSM8996_VERSIONS == msm8996_version) { > + dev_err(cpu_dev_silver, "Not Snapdragon 820/821!"); > + return -ENODEV; > + } > + > + np = dev_pm_opp_of_get_opp_desc_node(cpu_dev_silver); > + if (IS_ERR_OR_NULL(np)) same here. > + return PTR_ERR(np); > + > + if (!of_device_is_compatible(np, "operating-points-v2-kryo-cpu")) { > + ret = -ENOENT; > + goto free_np; > + } > + > + speedbin_nvmem = of_nvmem_cell_get(np, NULL); > + if (IS_ERR(speedbin_nvmem)) { > + ret = PTR_ERR(speedbin_nvmem); > + dev_err(cpu_dev_silver, "Could not get nvmem cell: %d\n", ret); > + goto free_np; > + } > + > + speedbin = nvmem_cell_read(speedbin_nvmem, &len); > + nvmem_cell_put(speedbin_nvmem); > + > + switch (msm8996_version) { > + case MSM8996_V3: > + versions = 1 << (unsigned int)(*speedbin); > + break; > + case MSM8996_SG: > + versions = 1 << ((unsigned int)(*speedbin) + 4); > + break; > + default: > + BUG(); > + break; > + } > + > + opp_silver = dev_pm_opp_set_supported_hw(cpu_dev_silver,&versions,1); > + if (IS_ERR(opp_silver)) { > + dev_err(cpu_dev_silver, "Failed to set supported hardware\n"); > + ret = PTR_ERR(opp_silver); > + goto free_np; > + } > + > + opp_gold = dev_pm_opp_set_supported_hw(cpu_dev_gold,&versions,1); > + if (IS_ERR(opp_gold)) { > + dev_err(cpu_dev_gold, "Failed to set supported hardware\n"); > + ret = PTR_ERR(opp_gold); > + goto free_opp_silver; > + } > + > + pdev = platform_device_register_simple("cpufreq-dt", -1, NULL, 0); and this only returns ERR_PTR() on error. > + if (!IS_ERR_OR_NULL(pdev)) > + return 0; > + > + ret = PTR_ERR(pdev); > + dev_err(cpu_dev_silver, "Failed to register platform device\n"); > + dev_pm_opp_put_supported_hw(opp_gold); > + > +free_opp_silver: > + dev_pm_opp_put_supported_hw(opp_silver); > + > +free_np: > + of_node_put(np); > + > + return ret; > +} > +late_initcall(qcom_cpufreq_kryo_driver_init); > + > +MODULE_DESCRIPTION("Qualcomm Technologies, Inc. Kryo CPUfreq driver"); > +MODULE_LICENSE("GPL v2"); > -- > 1.9.1 -- viresh -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html