drivers/mailbox/qcom-apcs-ipc-mailbox.c

   1 /*
   2  * Copyright (c) 2017, Linaro Ltd
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 and
   6  * only version 2 as published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  */
  13
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/io.h>
  17 #include <linux/slab.h>
  18 #include <linux/of.h>
  19 #include <linux/of_platform.h>
  20 #include <linux/platform_device.h>
  21 #include <linux/mailbox_controller.h>
  22
  23 #define QCOM_APCS_IPC_BITS      32
  24
  25 struct qcom_apcs_ipc {
  26         struct mbox_controller mbox;
  27         struct mbox_chan mbox_chans[QCOM_APCS_IPC_BITS];
  28
  29         void __iomem *reg;
  30         unsigned long offset;
  31 };
  32
  33 static int qcom_apcs_ipc_send_data(struct mbox_chan *chan, void *data)
  34 {
  35         struct qcom_apcs_ipc *apcs = container_of(chan->mbox,
  36                                                   struct qcom_apcs_ipc, mbox);
  37         unsigned long idx = (unsigned long)chan->con_priv;
  38
  39         writel(BIT(idx), apcs->reg);
  40
  41         return 0;
  42 }
  43
  44 static const struct mbox_chan_ops qcom_apcs_ipc_ops = {
  45         .send_data = qcom_apcs_ipc_send_data,
  46 };
  47
  48 static int qcom_apcs_ipc_probe(struct platform_device *pdev)
  49 {
  50         struct qcom_apcs_ipc *apcs;
  51         struct resource *res;
  52         unsigned long offset;
  53         void __iomem *base;
  54         unsigned long i;
  55         int ret;
  56
  57         apcs = devm_kzalloc(&pdev->dev, sizeof(*apcs), GFP_KERNEL);
  58         if (!apcs)
  59                 return -ENOMEM;
  60
  61         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
  62         base = devm_ioremap_resource(&pdev->dev, res);
  63         if (IS_ERR(base))
  64                 return PTR_ERR(base);
  65
  66         offset = (unsigned long)of_device_get_match_data(&pdev->dev);
  67
  68         apcs->reg = base + offset;
  69
  70         /* Initialize channel identifiers */
  71         for (i = 0; i < ARRAY_SIZE(apcs->mbox_chans); i++)
  72                 apcs->mbox_chans[i].con_priv = (void *)i;
  73
  74         apcs->mbox.dev = &pdev->dev;
  75         apcs->mbox.ops = &qcom_apcs_ipc_ops;
  76         apcs->mbox.chans = apcs->mbox_chans;
  77         apcs->mbox.num_chans = ARRAY_SIZE(apcs->mbox_chans);
  78
  79         ret = mbox_controller_register(&apcs->mbox);
  80         if (ret) {
  81                 dev_err(&pdev->dev, "failed to register APCS IPC controller\n");
  82                 return ret;
  83         }
  84
  85         platform_set_drvdata(pdev, apcs);
  86
  87         return 0;
  88 }
  89
  90 static int qcom_apcs_ipc_remove(struct platform_device *pdev)
  91 {
  92         struct qcom_apcs_ipc *apcs = platform_get_drvdata(pdev);
  93
  94         mbox_controller_unregister(&apcs->mbox);
  95
  96         return 0;
  97 }
  98
  99 /* .data is the offset of the ipc register within the global block */
 100 static const struct of_device_id qcom_apcs_ipc_of_match[] = {
 101         { .compatible = "qcom,msm8916-apcs-kpss-global", .data = (void *)8 },
 102         { .compatible = "qcom,msm8996-apcs-hmss-global", .data = (void *)16 },
 103         {}
 104 };
 105 MODULE_DEVICE_TABLE(of, qcom_apcs_ipc_of_match);
 106
 107 static struct platform_driver qcom_apcs_ipc_driver = {
 108         .probe = qcom_apcs_ipc_probe,
 109         .remove = qcom_apcs_ipc_remove,
 110         .driver = {
 111                 .name = "qcom_apcs_ipc",
 112                 .of_match_table = qcom_apcs_ipc_of_match,
 113         },
 114 };
 115
 116 static int __init qcom_apcs_ipc_init(void)
 117 {
 118         return platform_driver_register(&qcom_apcs_ipc_driver);
 119 }
 120 postcore_initcall(qcom_apcs_ipc_init);
 121
 122 static void __exit qcom_apcs_ipc_exit(void)
 123 {
 124         platform_driver_unregister(&qcom_apcs_ipc_driver);
 125 }
 126 module_exit(qcom_apcs_ipc_exit);
 127
 128 MODULE_LICENSE("GPL v2");
 129 MODULE_DESCRIPTION("Qualcomm APCS IPC driver");