drivers/interconnect/qcom/smd-rpm.c

   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 int qcom_icc_rpm_smd_remove(struct platform_device *pdev)
  67 {
  68         icc_smd_rpm = NULL;
  69
  70         return 0;
  71 }
  72
  73 static int qcom_icc_rpm_smd_probe(struct platform_device *pdev)
  74 {
  75         icc_smd_rpm = dev_get_drvdata(pdev->dev.parent);
  76
  77         if (!icc_smd_rpm) {
  78                 dev_err(&pdev->dev, "unable to retrieve handle to RPM\n");
  79                 return -ENODEV;
  80         }
  81
  82         return 0;
  83 }
  84
  85 static struct platform_driver qcom_interconnect_rpm_smd_driver = {
  86         .driver = {
  87                 .name           = "icc_smd_rpm",
  88         },
  89         .probe = qcom_icc_rpm_smd_probe,
  90         .remove = qcom_icc_rpm_smd_remove,
  91 };
  92 module_platform_driver(qcom_interconnect_rpm_smd_driver);
  93 MODULE_AUTHOR("Georgi Djakov <georgi.djakov@linaro.org>");
  94 MODULE_DESCRIPTION("Qualcomm SMD RPM interconnect proxy driver");
  95 MODULE_LICENSE("GPL v2");
  96 MODULE_ALIAS("platform:icc_smd_rpm");