common.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Copyright (C) 2014 NVIDIA CORPORATION.  All rights reserved.
  4 */
  5
  6#define dev_fmt(fmt)	"tegra-soc: " fmt
  7
  8#include <linux/clk.h>
  9#include <linux/device.h>
 10#include <linux/export.h>
 11#include <linux/of.h>
 12#include <linux/pm_opp.h>
 13#include <linux/pm_runtime.h>
 14
 15#include <soc/tegra/common.h>
 16#include <soc/tegra/fuse.h>
 17
 18static const struct of_device_id tegra_machine_match[] = {
 19	{ .compatible = "nvidia,tegra20", },
 20	{ .compatible = "nvidia,tegra30", },
 21	{ .compatible = "nvidia,tegra114", },
 22	{ .compatible = "nvidia,tegra124", },
 23	{ .compatible = "nvidia,tegra132", },
 24	{ .compatible = "nvidia,tegra210", },
 25	{ }
 26};
 27
 28bool soc_is_tegra(void)
 29{
 30	return of_machine_device_match(tegra_machine_match);
 31}
 32
 33static int tegra_core_dev_init_opp_state(struct device *dev)
 34{
 35	unsigned long rate;
 36	struct clk *clk;
 37	bool rpm_enabled;
 38	int err;
 39
 40	clk = devm_clk_get(dev, NULL);
 41	if (IS_ERR(clk)) {
 42		dev_err(dev, "failed to get clk: %pe\n", clk);
 43		return PTR_ERR(clk);
 44	}
 45
 46	rate = clk_get_rate(clk);
 47	if (!rate) {
 48		dev_err(dev, "failed to get clk rate\n");
 49		return -EINVAL;
 50	}
 51
 52	/*
 53	 * Runtime PM of the device must be enabled in order to set up
 54	 * GENPD's performance properly because GENPD core checks whether
 55	 * device is suspended and this check doesn't work while RPM is
 56	 * disabled. This makes sure the OPP vote below gets cached in
 57	 * GENPD for the device. Instead, the vote is done the next time
 58	 * the device gets runtime resumed.
 59	 */
 60	rpm_enabled = pm_runtime_enabled(dev);
 61	if (!rpm_enabled)
 62		pm_runtime_enable(dev);
 63
 64	/* should never happen in practice */
 65	if (!pm_runtime_enabled(dev)) {
 66		dev_WARN(dev, "failed to enable runtime PM\n");
 67		pm_runtime_disable(dev);
 68		return -EINVAL;
 69	}
 70
 71	/* first dummy rate-setting initializes voltage vote */
 72	err = dev_pm_opp_set_rate(dev, rate);
 73
 74	if (!rpm_enabled)
 75		pm_runtime_disable(dev);
 76
 77	if (err) {
 78		dev_err(dev, "failed to initialize OPP clock: %d\n", err);
 79		return err;
 80	}
 81
 82	return 0;
 83}
 84
 85/**
 86 * devm_tegra_core_dev_init_opp_table() - initialize OPP table
 87 * @dev: device for which OPP table is initialized
 88 * @params: pointer to the OPP table configuration
 89 *
 90 * This function will initialize OPP table and sync OPP state of a Tegra SoC
 91 * core device.
 92 *
 93 * Return: 0 on success or errorno.
 94 */
 95int devm_tegra_core_dev_init_opp_table(struct device *dev,
 96				       struct tegra_core_opp_params *params)
 97{
 98	u32 hw_version;
 99	int err;
100	/*
101	 * The clk's connection id to set is NULL and this is a NULL terminated
102	 * array, hence two NULL entries.
103	 */
104	const char *clk_names[] = { NULL, NULL };
105	struct dev_pm_opp_config config = {
106		/*
107		 * For some devices we don't have any OPP table in the DT, and
108		 * in order to use the same code path for all the devices, we
109		 * create a dummy OPP table for them via this. The dummy OPP
110		 * table is only capable of doing clk_set_rate() on invocation
111		 * of dev_pm_opp_set_rate() and doesn't provide any other
112		 * functionality.
113		 */
114		.clk_names = clk_names,
115	};
116
117	if (of_machine_is_compatible("nvidia,tegra20")) {
118		hw_version = BIT(tegra_sku_info.soc_process_id);
119		config.supported_hw = &hw_version;
120		config.supported_hw_count = 1;
121	} else if (of_machine_is_compatible("nvidia,tegra30")) {
122		hw_version = BIT(tegra_sku_info.soc_speedo_id);
123		config.supported_hw = &hw_version;
124		config.supported_hw_count = 1;
125	}
126
127	err = devm_pm_opp_set_config(dev, &config);
128	if (err) {
129		dev_err(dev, "failed to set OPP config: %d\n", err);
130		return err;
131	}
132
133	/*
134	 * Tegra114+ doesn't support OPP yet, return early for non tegra20/30
135	 * case.
136	 */
137	if (!config.supported_hw)
138		return -ENODEV;
139
140	/*
141	 * Older device-trees have an empty OPP table, we will get
142	 * -ENODEV from devm_pm_opp_of_add_table() in this case.
143	 */
144	err = devm_pm_opp_of_add_table(dev);
145	if (err) {
146		if (err != -ENODEV)
147			dev_err(dev, "failed to add OPP table: %d\n", err);
148
149		return err;
150	}
151
152	if (params->init_state) {
153		err = tegra_core_dev_init_opp_state(dev);
154		if (err)
155			return err;
156	}
157
158	return 0;
159}
160EXPORT_SYMBOL_GPL(devm_tegra_core_dev_init_opp_table);