1 // SPDX-License-Identifier: GPL-2.0+
3  * Voltage regulators coupler for NVIDIA Tegra30
4  * Copyright (C) 2019 GRATE-DRIVER project
7  * Copyright (C) 2010-2011 NVIDIA Corporation
10 #define pr_fmt(fmt)	"tegra voltage-coupler: " fmt
48 	 * Tegra30 SoC has critical DVFS-capable devices that are  in tegra30_core_limit()
49 	 * permanently-active or active at a boot time, like EMC  in tegra30_core_limit()
55 	 * the state of all DVFS-critical CORE devices is synced.  in tegra30_core_limit()
57 	if (tegra_pmc_core_domain_state_synced() && !tegra->sys_reboot_mode) {  in tegra30_core_limit()
62 	if (tegra->core_min_uV > 0)  in tegra30_core_limit()
63 		return tegra->core_min_uV;  in tegra30_core_limit()
78 	 * whatever maximum value defined via board's device-tree.  in tegra30_core_limit()
80 	tegra->core_min_uV = core_max_uV;  in tegra30_core_limit()
82 	pr_info("core voltage initialized to %duV\n", tegra->core_min_uV);  in tegra30_core_limit()
84 	return tegra->core_min_uV;  in tegra30_core_limit()
113 	return -EINVAL;  in tegra30_core_cpu_limit()
136 	 * by the CORE voltage. This applies to all Tegra30 SoC's.  in tegra30_voltage_update()
138 	max_spread = cpu_rdev->constraints->max_spread[0];  in tegra30_voltage_update()
139 	cpu_max_step = cpu_rdev->constraints->max_uV_step;  in tegra30_voltage_update()
140 	core_max_step = core_rdev->constraints->max_uV_step;  in tegra30_voltage_update()
143 		pr_err_once("cpu-core max-spread is undefined in device-tree\n");  in tegra30_voltage_update()
148 		pr_err_once("cpu max-step is undefined in device-tree\n");  in tegra30_voltage_update()
153 		pr_err_once("core max-step is undefined in device-tree\n");  in tegra30_voltage_update()
175 	cpu_min_uV = core_min_uV - max_spread;  in tegra30_voltage_update()
196 	if (!tegra->cpu_min_uV)  in tegra30_voltage_update()
197 		tegra->cpu_min_uV = cpu_uV;  in tegra30_voltage_update()
223 	if (tegra->sys_reboot_mode)  in tegra30_voltage_update()
224 		cpu_min_uV = max(cpu_min_uV, tegra->cpu_min_uV);  in tegra30_voltage_update()
236 			cpu_target_uV = max(cpu_uV - cpu_max_step, cpu_min_uV);  in tegra30_voltage_update()
237 			cpu_target_uV = max(core_uV - max_spread, cpu_target_uV);  in tegra30_voltage_update()
262 			core_target_uV = max(core_target_uV, core_uV - core_max_step);  in tegra30_voltage_update()
286 	struct regulator_dev *core_rdev = tegra->core_rdev;  in tegra30_regulator_balance_voltage()
287 	struct regulator_dev *cpu_rdev = tegra->cpu_rdev;  in tegra30_regulator_balance_voltage()
291 		return -EINVAL;  in tegra30_regulator_balance_voltage()
294 	tegra->sys_reboot_mode = READ_ONCE(tegra->sys_reboot_mode_req);  in tegra30_regulator_balance_voltage()
304 	if (!tegra->core_rdev || !tegra->cpu_rdev)  in tegra30_regulator_prepare_reboot()
307 	WRITE_ONCE(tegra->sys_reboot_mode_req, true);  in tegra30_regulator_prepare_reboot()
310 	 * Some devices use CPU soft-reboot method and in this case we  in tegra30_regulator_prepare_reboot()
314 	err = regulator_sync_voltage_rdev(tegra->cpu_rdev);  in tegra30_regulator_prepare_reboot()
318 	err = regulator_sync_voltage_rdev(tegra->core_rdev);  in tegra30_regulator_prepare_reboot()
322 	WRITE_ONCE(tegra->sys_reboot_mode_req, sys_reboot_mode);  in tegra30_regulator_prepare_reboot()
348 	struct device_node *np = rdev->dev.of_node;  in tegra30_regulator_attach()
350 	if (of_property_read_bool(np, "nvidia,tegra-core-regulator") &&  in tegra30_regulator_attach()
351 	    !tegra->core_rdev) {  in tegra30_regulator_attach()
352 		tegra->core_rdev = rdev;  in tegra30_regulator_attach()
356 	if (of_property_read_bool(np, "nvidia,tegra-cpu-regulator") &&  in tegra30_regulator_attach()
357 	    !tegra->cpu_rdev) {  in tegra30_regulator_attach()
358 		tegra->cpu_rdev = rdev;  in tegra30_regulator_attach()
362 	return -EINVAL;  in tegra30_regulator_attach()
376 		return -EPERM;  in tegra30_regulator_detach()
378 	if (tegra->core_rdev == rdev) {  in tegra30_regulator_detach()
379 		tegra->core_rdev = NULL;  in tegra30_regulator_detach()
383 	if (tegra->cpu_rdev == rdev) {  in tegra30_regulator_detach()
384 		tegra->cpu_rdev = NULL;  in tegra30_regulator_detach()
388 	return -EINVAL;  in tegra30_regulator_detach()
404 	if (!of_machine_is_compatible("nvidia,tegra30"))  in tegra_regulator_coupler_init()