xref: /linux/drivers/interconnect/qcom/smd-rpm.c (revision 4b660dbd9ee2059850fd30e0df420ca7a38a1856)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * RPM over SMD communication wrapper for interconnects
4  *
5  * Copyright (C) 2019 Linaro Ltd
6  * Author: Georgi Djakov <georgi.djakov@linaro.org>
7  */
8 
9 #include <linux/interconnect-provider.h>
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/soc/qcom/smd-rpm.h>
13 
14 #include "icc-rpm.h"
15 
16 #define RPM_KEY_BW		0x00007762
17 #define QCOM_RPM_SMD_KEY_RATE	0x007a484b
18 
19 static struct qcom_smd_rpm *icc_smd_rpm;
20 
21 struct icc_rpm_smd_req {
22 	__le32 key;
23 	__le32 nbytes;
24 	__le32 value;
25 };
26 
27 bool qcom_icc_rpm_smd_available(void)
28 {
29 	return !!icc_smd_rpm;
30 }
31 EXPORT_SYMBOL_GPL(qcom_icc_rpm_smd_available);
32 
33 int qcom_icc_rpm_smd_send(int ctx, int rsc_type, int id, u32 val)
34 {
35 	struct icc_rpm_smd_req req = {
36 		.key = cpu_to_le32(RPM_KEY_BW),
37 		.nbytes = cpu_to_le32(sizeof(u32)),
38 		.value = cpu_to_le32(val),
39 	};
40 
41 	return qcom_rpm_smd_write(icc_smd_rpm, ctx, rsc_type, id, &req,
42 				  sizeof(req));
43 }
44 EXPORT_SYMBOL_GPL(qcom_icc_rpm_smd_send);
45 
46 int qcom_icc_rpm_set_bus_rate(const struct rpm_clk_resource *clk, int ctx, u32 rate)
47 {
48 	struct clk_smd_rpm_req req = {
49 		.key = cpu_to_le32(QCOM_RPM_SMD_KEY_RATE),
50 		.nbytes = cpu_to_le32(sizeof(u32)),
51 	};
52 
53 	/* Branch clocks are only on/off */
54 	if (clk->branch)
55 		rate = !!rate;
56 
57 	req.value = cpu_to_le32(rate);
58 	return qcom_rpm_smd_write(icc_smd_rpm,
59 				  ctx,
60 				  clk->resource_type,
61 				  clk->clock_id,
62 				  &req, sizeof(req));
63 }
64 EXPORT_SYMBOL_GPL(qcom_icc_rpm_set_bus_rate);
65 
66 static void qcom_icc_rpm_smd_remove(struct platform_device *pdev)
67 {
68 	icc_smd_rpm = NULL;
69 }
70 
71 static int qcom_icc_rpm_smd_probe(struct platform_device *pdev)
72 {
73 	icc_smd_rpm = dev_get_drvdata(pdev->dev.parent);
74 
75 	if (!icc_smd_rpm) {
76 		dev_err(&pdev->dev, "unable to retrieve handle to RPM\n");
77 		return -ENODEV;
78 	}
79 
80 	return 0;
81 }
82 
83 static struct platform_driver qcom_interconnect_rpm_smd_driver = {
84 	.driver = {
85 		.name		= "icc_smd_rpm",
86 	},
87 	.probe = qcom_icc_rpm_smd_probe,
88 	.remove_new = qcom_icc_rpm_smd_remove,
89 };
90 module_platform_driver(qcom_interconnect_rpm_smd_driver);
91 MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
92 MODULE_DESCRIPTION("Qualcomm SMD RPM interconnect proxy driver");
93 MODULE_LICENSE("GPL v2");
94 MODULE_ALIAS("platform:icc_smd_rpm");
95