27  * Mediatek SoCs has two voltage inputs, Vproc and Vsram. In some cases the two
29  * 100mV < Vsram - Vproc < 200mV
68 	int old_vproc, old_vsram, new_vsram, vsram, vproc, ret;  in mtk_cpufreq_voltage_tracking()  local
75 	/* Vsram should not exceed the maximum allowed voltage of SoC. */  in mtk_cpufreq_voltage_tracking()
80 		 * When scaling up voltages, Vsram and Vproc scale up step  in mtk_cpufreq_voltage_tracking()
81 		 * by step. At each step, set Vsram to (Vproc + 200mV) first,  in mtk_cpufreq_voltage_tracking()
82 		 * then set Vproc to (Vsram - 100mV).  in mtk_cpufreq_voltage_tracking()
83 		 * Keep doing it until Vsram and Vproc hit target voltages.  in mtk_cpufreq_voltage_tracking()
88 				pr_err("%s: invalid Vsram value: %d\n",  in mtk_cpufreq_voltage_tracking()
99 			vsram = min(new_vsram, old_vproc + MAX_VOLT_SHIFT);  in mtk_cpufreq_voltage_tracking()
101 			if (vsram + VOLT_TOL >= MAX_VOLT_LIMIT) {  in mtk_cpufreq_voltage_tracking()
102 				vsram = MAX_VOLT_LIMIT;  in mtk_cpufreq_voltage_tracking()
105 				 * If the target Vsram hits the maximum voltage,  in mtk_cpufreq_voltage_tracking()
108 				ret = regulator_set_voltage(sram_reg, vsram,  in mtk_cpufreq_voltage_tracking()
109 							    vsram);  in mtk_cpufreq_voltage_tracking()
112 							vsram - VOLT_TOL,  in mtk_cpufreq_voltage_tracking()
113 							vsram);  in mtk_cpufreq_voltage_tracking()
117 				ret = regulator_set_voltage(sram_reg, vsram,  in mtk_cpufreq_voltage_tracking()
118 							    vsram + VOLT_TOL);  in mtk_cpufreq_voltage_tracking()
120 				vproc = vsram - MIN_VOLT_SHIFT;  in mtk_cpufreq_voltage_tracking()
132 		} while (vproc < new_vproc || vsram < new_vsram);  in mtk_cpufreq_voltage_tracking()
135 		 * When scaling down voltages, Vsram and Vproc scale down step  in mtk_cpufreq_voltage_tracking()
136 		 * by step. At each step, set Vproc to (Vsram - 200mV) first,  in mtk_cpufreq_voltage_tracking()
138 		 * Keep doing it until Vsram and Vproc hit target voltages.  in mtk_cpufreq_voltage_tracking()
149 				pr_err("%s: invalid Vsram value: %d\n",  in mtk_cpufreq_voltage_tracking()
161 				vsram = new_vsram;  in mtk_cpufreq_voltage_tracking()
163 				vsram = max(new_vsram, vproc + MIN_VOLT_SHIFT);  in mtk_cpufreq_voltage_tracking()
165 			if (vsram + VOLT_TOL >= MAX_VOLT_LIMIT) {  in mtk_cpufreq_voltage_tracking()
166 				vsram = MAX_VOLT_LIMIT;  in mtk_cpufreq_voltage_tracking()
169 				 * If the target Vsram hits the maximum voltage,  in mtk_cpufreq_voltage_tracking()
172 				ret = regulator_set_voltage(sram_reg, vsram,  in mtk_cpufreq_voltage_tracking()
173 							    vsram);  in mtk_cpufreq_voltage_tracking()
176 							vsram - VOLT_TOL,  in mtk_cpufreq_voltage_tracking()
177 							vsram);  in mtk_cpufreq_voltage_tracking()
179 				ret = regulator_set_voltage(sram_reg, vsram,  in mtk_cpufreq_voltage_tracking()
180 							    vsram + VOLT_TOL);  in mtk_cpufreq_voltage_tracking()
189 			 vsram > new_vsram + VOLT_TOL);  in mtk_cpufreq_voltage_tracking()