102 lines
2.4 KiB
C
102 lines
2.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) STMicroelectronics 2019 - All Rights Reserved
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* Authors: Alexandre Torgue <alexandre.torgue@st.com> for STMicroelectronics.
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*/
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#include <linux/cpu.h>
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#include <linux/cpufreq.h>
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/nvmem-consumer.h>
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#include <linux/of_platform.h>
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#include <linux/pm_opp.h>
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struct stm32_cpufreq_priv {
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struct opp_table *opps;
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struct platform_device *cpufreq_dt_pdev;
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};
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static int stm32_cpufreq_probe(struct platform_device *pdev)
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{
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struct stm32_cpufreq_priv *priv;
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struct device_node *opp_node;
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struct device *cpu_dev;
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u8 part_number;
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u32 supported_hw;
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int ret;
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cpu_dev = get_cpu_device(0);
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if (!cpu_dev) {
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dev_err(&pdev->dev, "failed to get cpu0 device\n");
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return -ENODEV;
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}
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opp_node = dev_pm_opp_of_get_opp_desc_node(cpu_dev);
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if (!opp_node) {
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dev_err(&pdev->dev, "OPP-v2 not supported\n");
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return -ENODEV;
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}
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/* Get chip info */
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ret = nvmem_cell_read_u8(cpu_dev, "part_number", &part_number);
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if (ret) {
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dev_err(&pdev->dev, "Failed to get chip info: %d\n", ret);
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return ret;
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}
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supported_hw = BIT((part_number & 0x80) >> 7);
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priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
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if (!priv)
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return -ENOMEM;
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priv->opps = dev_pm_opp_set_supported_hw(cpu_dev, &supported_hw, 1);
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if (IS_ERR(priv->opps)) {
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ret = PTR_ERR(priv->opps);
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if (ret != -EPROBE_DEFER)
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dev_err(&pdev->dev, "Failed to set supported opp: %d\n",
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ret);
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return ret;
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}
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of_node_put(opp_node);
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priv->cpufreq_dt_pdev = platform_device_register_simple("cpufreq-dt",
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-1, NULL, 0);
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platform_set_drvdata(pdev, priv);
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return 0;
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}
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static int stm32_cpufreq_remove(struct platform_device *pdev)
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{
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struct stm32_cpufreq_priv *priv = platform_get_drvdata(pdev);
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platform_device_unregister(priv->cpufreq_dt_pdev);
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dev_pm_opp_put_supported_hw(priv->opps);
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return 0;
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}
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static int stm32_cpufreq_init(void)
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{
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platform_device_register_simple("stm32-cpufreq", -1, NULL, 0);
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return 0;
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}
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module_init(stm32_cpufreq_init);
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static struct platform_driver stm32_cpufreq_platdrv = {
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.driver = {
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.name = "stm32-cpufreq",
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},
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.probe = stm32_cpufreq_probe,
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.remove = stm32_cpufreq_remove,
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};
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module_platform_driver(stm32_cpufreq_platdrv);
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MODULE_DESCRIPTION("STM32 CPU freq driver");
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MODULE_AUTHOR("Alexandre Torgue <alexandre.torgue@st.com>");
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MODULE_LICENSE("GPL v2");
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