c2147585cc
Early samples without fuses written report "0 0" which means consumer
segment and minimum speed grading. According to datasheet the minimum speed
grade is not supported for consumer parts so all OPPs are disabled
which results in stack dumps later on.
Fix by clamping minimum consumer speed grade to 1 on imx8mm and imx8mq.
Fixes: 4d28ba1d62 ("cpufreq: Add imx-cpufreq-dt driver")
Signed-off-by: Leonard Crestez <leonard.crestez@nxp.com>
[ Viresh: s/minumum/minimum/ in patch and log ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
112 lines
3.1 KiB
C
112 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright 2019 NXP
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*/
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#include <linux/cpu.h>
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#include <linux/err.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.h>
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#include <linux/platform_device.h>
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#include <linux/pm_opp.h>
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#include <linux/slab.h>
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#define OCOTP_CFG3_SPEED_GRADE_SHIFT 8
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#define OCOTP_CFG3_SPEED_GRADE_MASK (0x3 << 8)
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#define OCOTP_CFG3_MKT_SEGMENT_SHIFT 6
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#define OCOTP_CFG3_MKT_SEGMENT_MASK (0x3 << 6)
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static const struct of_device_id imx_cpufreq_dt_match_list[] = {
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{ .compatible = "fsl,imx8mm" },
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{ .compatible = "fsl,imx8mq" },
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{}
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};
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/* cpufreq-dt device registered by imx-cpufreq-dt */
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static struct platform_device *cpufreq_dt_pdev;
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static struct opp_table *cpufreq_opp_table;
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static int imx_cpufreq_dt_probe(struct platform_device *pdev)
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{
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struct device *cpu_dev = get_cpu_device(0);
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struct device_node *np;
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const struct of_device_id *match;
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u32 cell_value, supported_hw[2];
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int speed_grade, mkt_segment;
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int ret;
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np = of_find_node_by_path("/");
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match = of_match_node(imx_cpufreq_dt_match_list, np);
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of_node_put(np);
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if (!match)
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return -ENODEV;
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ret = nvmem_cell_read_u32(cpu_dev, "speed_grade", &cell_value);
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if (ret)
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return ret;
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speed_grade = (cell_value & OCOTP_CFG3_SPEED_GRADE_MASK) >> OCOTP_CFG3_SPEED_GRADE_SHIFT;
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mkt_segment = (cell_value & OCOTP_CFG3_MKT_SEGMENT_MASK) >> OCOTP_CFG3_MKT_SEGMENT_SHIFT;
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/*
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* Early samples without fuses written report "0 0" which means
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* consumer segment and minimum speed grading.
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*
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* According to datasheet minimum speed grading is not supported for
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* consumer parts so clamp to 1 to avoid warning for "no OPPs"
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*
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* Applies to 8mq and 8mm.
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*/
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if (mkt_segment == 0 && speed_grade == 0 && (
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!strcmp(match->compatible, "fsl,imx8mm") ||
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!strcmp(match->compatible, "fsl,imx8mq")))
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speed_grade = 1;
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supported_hw[0] = BIT(speed_grade);
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supported_hw[1] = BIT(mkt_segment);
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dev_info(&pdev->dev, "cpu speed grade %d mkt segment %d supported-hw %#x %#x\n",
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speed_grade, mkt_segment, supported_hw[0], supported_hw[1]);
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cpufreq_opp_table = dev_pm_opp_set_supported_hw(cpu_dev, supported_hw, 2);
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if (IS_ERR(cpufreq_opp_table)) {
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ret = PTR_ERR(cpufreq_opp_table);
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dev_err(&pdev->dev, "Failed to set supported opp: %d\n", ret);
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return ret;
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}
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cpufreq_dt_pdev = platform_device_register_data(
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&pdev->dev, "cpufreq-dt", -1, NULL, 0);
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if (IS_ERR(cpufreq_dt_pdev)) {
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dev_pm_opp_put_supported_hw(cpufreq_opp_table);
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ret = PTR_ERR(cpufreq_dt_pdev);
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dev_err(&pdev->dev, "Failed to register cpufreq-dt: %d\n", ret);
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return ret;
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}
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return 0;
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}
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static int imx_cpufreq_dt_remove(struct platform_device *pdev)
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{
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platform_device_unregister(cpufreq_dt_pdev);
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dev_pm_opp_put_supported_hw(cpufreq_opp_table);
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return 0;
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}
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static struct platform_driver imx_cpufreq_dt_driver = {
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.probe = imx_cpufreq_dt_probe,
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.remove = imx_cpufreq_dt_remove,
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.driver = {
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.name = "imx-cpufreq-dt",
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},
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};
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module_platform_driver(imx_cpufreq_dt_driver);
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MODULE_ALIAS("platform:imx-cpufreq-dt");
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MODULE_DESCRIPTION("Freescale i.MX cpufreq speed grading driver");
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MODULE_LICENSE("GPL v2");
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