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 device *cpu_dev;
35 static int cpufreq_opp_token;
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 
imx7ulp_get_intermediate(struct cpufreq_policy * policy,unsigned int index)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 
imx7ulp_target_intermediate(struct cpufreq_policy * policy,unsigned int index)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 
imx_cpufreq_dt_probe(struct platform_device * pdev)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_property_present(cpu_dev->of_node, "cpu-supply"))
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_token = dev_pm_opp_set_supported_hw(cpu_dev, supported_hw, 2);
157 	if (cpufreq_opp_token < 0) {
158 		ret = cpufreq_opp_token;
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_token);
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 
imx_cpufreq_dt_remove(struct platform_device * pdev)175 static void 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_token);
180 	else
181 		clk_bulk_put(ARRAY_SIZE(imx7ulp_clks), imx7ulp_clks);
182 }
183 
184 static struct platform_driver imx_cpufreq_dt_driver = {
185 	.probe = imx_cpufreq_dt_probe,
186 	.remove_new = imx_cpufreq_dt_remove,
187 	.driver = {
188 		.name = "imx-cpufreq-dt",
189 	},
190 };
191 module_platform_driver(imx_cpufreq_dt_driver);
192 
193 MODULE_ALIAS("platform:imx-cpufreq-dt");
194 MODULE_DESCRIPTION("Freescale i.MX cpufreq speed grading driver");
195 MODULE_LICENSE("GPL v2");
196