drivers/cpufreq/sun50i-cpufreq-nvmem.c

1 // SPDX-License-Identifier: GPL-2.0
5  * The sun50i-cpufreq-nvmem driver reads the efuse value from the SoC to
6  * provide the OPP framework with required information.
13 #include <linux/arm-smccc.h>
16 #include <linux/nvmem-consumer.h>
39 	 * the slowest bin. Expected efuse values are 1-3, slowest  in sun50i_h6_efuse_xlate()
43 		return efuse_value - 1;  in sun50i_h6_efuse_xlate()
58  * Judging by the OPP tables in the vendor BSP, the quality order of the
59  * returned speedbin index is 4 -> 0/2 -> 3 -> 1, from worst to best.
60  * 0 and 2 seem identical from the OPP tables' point of view.
98 		pr_warn("sun50i-cpufreq-nvmem: unknown speed bin 0x%x, using default bin 0\n",  in sun50i_h616_efuse_xlate()
116 	{ .compatible = "allwinner,sun50i-h6-operating-points",
119 	{ .compatible = "allwinner,sun50i-h616-operating-points",
126  * dt_has_supported_hw() - Check if any OPPs use opp-supported-hw
128  * If we ask the cpufreq framework to use the opp-supported-hw feature, it
129  * will ignore every OPP node without that DT property. If none of the OPPs
132  * Returns true if we have at least one OPP with the opp-supported-hw property.
148 	for_each_child_of_node_scoped(np, opp) {  in dt_has_supported_hw()
149 		if (of_property_present(opp, "opp-supported-hw")) {  in dt_has_supported_hw()
159  * sun50i_cpufreq_get_efuse() - Determine speed grade from efuse value
161  * Returns non-negative speed bin index on success, a negative error
175 		return -ENODEV;  in sun50i_cpufreq_get_efuse()
180 		return -ENOENT;  in sun50i_cpufreq_get_efuse()
184 		return -ENOENT;  in sun50i_cpufreq_get_efuse()
186 	opp_data = match->data;  in sun50i_cpufreq_get_efuse()
198 	ret = opp_data->efuse_xlate(*speedbin);  in sun50i_cpufreq_get_efuse()
217 		return -ENOMEM;  in sun50i_cpufreq_nvmem_probe()
226 	 * We need at least one OPP with the "opp-supported-hw" property,  in sun50i_cpufreq_nvmem_probe()
227 	 * or else the upper layers will ignore every OPP and will bail out.  in sun50i_cpufreq_nvmem_probe()
242 			ret = -ENODEV;  in sun50i_cpufreq_nvmem_probe()
253 	cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt", -1,  in sun50i_cpufreq_nvmem_probe()
288 		.name = "sun50i-cpufreq-nvmem",
293 	{ .compatible = "allwinner,sun50i-h6" },
294 	{ .compatible = "allwinner,sun50i-h616" },
295 	{ .compatible = "allwinner,sun50i-h618" },
296 	{ .compatible = "allwinner,sun50i-h700" },
320 		return -ENODEV;  in sun50i_cpufreq_init()
327 		platform_device_register_simple("sun50i-cpufreq-nvmem",  in sun50i_cpufreq_init()
328 						-1, NULL, 0);  in sun50i_cpufreq_init()
345 MODULE_DESCRIPTION("Sun50i-h6 cpufreq driver");