drivers/cpufreq/imx-cpufreq-dt.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright 2019 NXP
   4  */
   5
   6 #include <linux/clk.h>
   7 #include <linux/cpu.h>
   8 #include <linux/cpufreq.h>
   9 #include <linux/err.h>
  10 #include <linux/init.h>
  11 #include <linux/kernel.h>
  12 #include <linux/module.h>
  13 #include <linux/nvmem-consumer.h>
  14 #include <linux/of.h>
  15 #include <linux/platform_device.h>
  16 #include <linux/pm_opp.h>
  17 #include <linux/regulator/consumer.h>
  18 #include <linux/slab.h>
  19
  20 #include "cpufreq-dt.h"
  21
  22 #define OCOTP_CFG3_SPEED_GRADE_SHIFT    8
  23 #define OCOTP_CFG3_SPEED_GRADE_MASK     (0x3 << 8)
  24 #define IMX8MN_OCOTP_CFG3_SPEED_GRADE_MASK      (0xf << 8)
  25 #define OCOTP_CFG3_MKT_SEGMENT_SHIFT    6
  26 #define OCOTP_CFG3_MKT_SEGMENT_MASK     (0x3 << 6)
  27 #define IMX8MP_OCOTP_CFG3_MKT_SEGMENT_SHIFT    5
  28 #define IMX8MP_OCOTP_CFG3_MKT_SEGMENT_MASK     (0x3 << 5)
  29
  30 #define IMX7ULP_MAX_RUN_FREQ    528000
  31
  32 /* cpufreq-dt device registered by imx-cpufreq-dt */
  33 static struct platform_device *cpufreq_dt_pdev;
  34 static struct opp_table *cpufreq_opp_table;
  35 static struct device *cpu_dev;
  36
  37 enum IMX7ULP_CPUFREQ_CLKS {
  38         ARM,
  39         CORE,
  40         SCS_SEL,
  41         HSRUN_CORE,
  42         HSRUN_SCS_SEL,
  43         FIRC,
  44 };
  45
  46 static struct clk_bulk_data imx7ulp_clks[] = {
  47         { .id = "arm" },
  48         { .id = "core" },
  49         { .id = "scs_sel" },
  50         { .id = "hsrun_core" },
  51         { .id = "hsrun_scs_sel" },
  52         { .id = "firc" },
  53 };
  54
  55 static unsigned int imx7ulp_get_intermediate(struct cpufreq_policy *policy,
  56                                              unsigned int index)
  57 {
  58         return clk_get_rate(imx7ulp_clks[FIRC].clk);
  59 }
  60
  61 static int imx7ulp_target_intermediate(struct cpufreq_policy *policy,
  62                                         unsigned int index)
  63 {
  64         unsigned int newfreq = policy->freq_table[index].frequency;
  65
  66         clk_set_parent(imx7ulp_clks[SCS_SEL].clk, imx7ulp_clks[FIRC].clk);
  67         clk_set_parent(imx7ulp_clks[HSRUN_SCS_SEL].clk, imx7ulp_clks[FIRC].clk);
  68
  69         if (newfreq > IMX7ULP_MAX_RUN_FREQ)
  70                 clk_set_parent(imx7ulp_clks[ARM].clk,
  71                                imx7ulp_clks[HSRUN_CORE].clk);
  72         else
  73                 clk_set_parent(imx7ulp_clks[ARM].clk, imx7ulp_clks[CORE].clk);
  74
  75         return 0;
  76 }
  77
  78 static struct cpufreq_dt_platform_data imx7ulp_data = {
  79         .target_intermediate = imx7ulp_target_intermediate,
  80         .get_intermediate = imx7ulp_get_intermediate,
  81 };
  82
  83 static int imx_cpufreq_dt_probe(struct platform_device *pdev)
  84 {
  85         struct platform_device *dt_pdev;
  86         u32 cell_value, supported_hw[2];
  87         int speed_grade, mkt_segment;
  88         int ret;
  89
  90         cpu_dev = get_cpu_device(0);
  91
  92         if (!of_find_property(cpu_dev->of_node, "cpu-supply", NULL))
  93                 return -ENODEV;
  94
  95         if (of_machine_is_compatible("fsl,imx7ulp")) {
  96                 ret = clk_bulk_get(cpu_dev, ARRAY_SIZE(imx7ulp_clks),
  97                                    imx7ulp_clks);
  98                 if (ret)
  99                         return ret;
 100
 101                 dt_pdev = platform_device_register_data(NULL, "cpufreq-dt",
 102                                                         -1, &imx7ulp_data,
 103                                                         sizeof(imx7ulp_data));
 104                 if (IS_ERR(dt_pdev)) {
 105                         clk_bulk_put(ARRAY_SIZE(imx7ulp_clks), imx7ulp_clks);
 106                         ret = PTR_ERR(dt_pdev);
 107                         dev_err(&pdev->dev, "Failed to register cpufreq-dt: %d\n", ret);
 108                         return ret;
 109                 }
 110
 111                 cpufreq_dt_pdev = dt_pdev;
 112
 113                 return 0;
 114         }
 115
 116         ret = nvmem_cell_read_u32(cpu_dev, "speed_grade", &cell_value);
 117         if (ret)
 118                 return ret;
 119
 120         if (of_machine_is_compatible("fsl,imx8mn") ||
 121             of_machine_is_compatible("fsl,imx8mp"))
 122                 speed_grade = (cell_value & IMX8MN_OCOTP_CFG3_SPEED_GRADE_MASK)
 123                               >> OCOTP_CFG3_SPEED_GRADE_SHIFT;
 124         else
 125                 speed_grade = (cell_value & OCOTP_CFG3_SPEED_GRADE_MASK)
 126                               >> OCOTP_CFG3_SPEED_GRADE_SHIFT;
 127
 128         if (of_machine_is_compatible("fsl,imx8mp"))
 129                 mkt_segment = (cell_value & IMX8MP_OCOTP_CFG3_MKT_SEGMENT_MASK)
 130                                >> IMX8MP_OCOTP_CFG3_MKT_SEGMENT_SHIFT;
 131         else
 132                 mkt_segment = (cell_value & OCOTP_CFG3_MKT_SEGMENT_MASK)
 133                                >> OCOTP_CFG3_MKT_SEGMENT_SHIFT;
 134
 135         /*
 136          * Early samples without fuses written report "0 0" which may NOT
 137          * match any OPP defined in DT. So clamp to minimum OPP defined in
 138          * DT to avoid warning for "no OPPs".
 139          *
 140          * Applies to i.MX8M series SoCs.
 141          */
 142         if (mkt_segment == 0 && speed_grade == 0) {
 143                 if (of_machine_is_compatible("fsl,imx8mm") ||
 144                     of_machine_is_compatible("fsl,imx8mq"))
 145                         speed_grade = 1;
 146                 if (of_machine_is_compatible("fsl,imx8mn") ||
 147                     of_machine_is_compatible("fsl,imx8mp"))
 148                         speed_grade = 0xb;
 149         }
 150
 151         supported_hw[0] = BIT(speed_grade);
 152         supported_hw[1] = BIT(mkt_segment);
 153         dev_info(&pdev->dev, "cpu speed grade %d mkt segment %d supported-hw %#x %#x\n",
 154                         speed_grade, mkt_segment, supported_hw[0], supported_hw[1]);
 155
 156         cpufreq_opp_table = dev_pm_opp_set_supported_hw(cpu_dev, supported_hw, 2);
 157         if (IS_ERR(cpufreq_opp_table)) {
 158                 ret = PTR_ERR(cpufreq_opp_table);
 159                 dev_err(&pdev->dev, "Failed to set supported opp: %d\n", ret);
 160                 return ret;
 161         }
 162
 163         cpufreq_dt_pdev = platform_device_register_data(
 164                         &pdev->dev, "cpufreq-dt", -1, NULL, 0);
 165         if (IS_ERR(cpufreq_dt_pdev)) {
 166                 dev_pm_opp_put_supported_hw(cpufreq_opp_table);
 167                 ret = PTR_ERR(cpufreq_dt_pdev);
 168                 dev_err(&pdev->dev, "Failed to register cpufreq-dt: %d\n", ret);
 169                 return ret;
 170         }
 171
 172         return 0;
 173 }
 174
 175 static int imx_cpufreq_dt_remove(struct platform_device *pdev)
 176 {
 177         platform_device_unregister(cpufreq_dt_pdev);
 178         if (!of_machine_is_compatible("fsl,imx7ulp"))
 179                 dev_pm_opp_put_supported_hw(cpufreq_opp_table);
 180         else
 181                 clk_bulk_put(ARRAY_SIZE(imx7ulp_clks), imx7ulp_clks);
 182
 183         return 0;
 184 }
 185
 186 static struct platform_driver imx_cpufreq_dt_driver = {
 187         .probe = imx_cpufreq_dt_probe,
 188         .remove = imx_cpufreq_dt_remove,
 189         .driver = {
 190                 .name = "imx-cpufreq-dt",
 191         },
 192 };
 193 module_platform_driver(imx_cpufreq_dt_driver);
 194
 195 MODULE_ALIAS("platform:imx-cpufreq-dt");
 196 MODULE_DESCRIPTION("Freescale i.MX cpufreq speed grading driver");
 197 MODULE_LICENSE("GPL v2");