linux/drivers/firmware/imx/imx-scu.c
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   1// SPDX-License-Identifier: GPL-2.0+
   2/*
   3 * Copyright 2018 NXP
   4 *  Author: Dong Aisheng <aisheng.dong@nxp.com>
   5 *
   6 * Implementation of the SCU IPC functions using MUs (client side).
   7 *
   8 */
   9
  10#include <linux/err.h>
  11#include <linux/firmware/imx/types.h>
  12#include <linux/firmware/imx/ipc.h>
  13#include <linux/firmware/imx/sci.h>
  14#include <linux/interrupt.h>
  15#include <linux/irq.h>
  16#include <linux/kernel.h>
  17#include <linux/mailbox_client.h>
  18#include <linux/module.h>
  19#include <linux/mutex.h>
  20#include <linux/of_platform.h>
  21#include <linux/platform_device.h>
  22
  23#define SCU_MU_CHAN_NUM         8
  24#define MAX_RX_TIMEOUT          (msecs_to_jiffies(30))
  25
  26struct imx_sc_chan {
  27        struct imx_sc_ipc *sc_ipc;
  28
  29        struct mbox_client cl;
  30        struct mbox_chan *ch;
  31        int idx;
  32};
  33
  34struct imx_sc_ipc {
  35        /* SCU uses 4 Tx and 4 Rx channels */
  36        struct imx_sc_chan chans[SCU_MU_CHAN_NUM];
  37        struct device *dev;
  38        struct mutex lock;
  39        struct completion done;
  40
  41        /* temporarily store the SCU msg */
  42        u32 *msg;
  43        u8 rx_size;
  44        u8 count;
  45};
  46
  47/*
  48 * This type is used to indicate error response for most functions.
  49 */
  50enum imx_sc_error_codes {
  51        IMX_SC_ERR_NONE = 0,    /* Success */
  52        IMX_SC_ERR_VERSION = 1, /* Incompatible API version */
  53        IMX_SC_ERR_CONFIG = 2,  /* Configuration error */
  54        IMX_SC_ERR_PARM = 3,    /* Bad parameter */
  55        IMX_SC_ERR_NOACCESS = 4,        /* Permission error (no access) */
  56        IMX_SC_ERR_LOCKED = 5,  /* Permission error (locked) */
  57        IMX_SC_ERR_UNAVAILABLE = 6,     /* Unavailable (out of resources) */
  58        IMX_SC_ERR_NOTFOUND = 7,        /* Not found */
  59        IMX_SC_ERR_NOPOWER = 8, /* No power */
  60        IMX_SC_ERR_IPC = 9,             /* Generic IPC error */
  61        IMX_SC_ERR_BUSY = 10,   /* Resource is currently busy/active */
  62        IMX_SC_ERR_FAIL = 11,   /* General I/O failure */
  63        IMX_SC_ERR_LAST
  64};
  65
  66static int imx_sc_linux_errmap[IMX_SC_ERR_LAST] = {
  67        0,       /* IMX_SC_ERR_NONE */
  68        -EINVAL, /* IMX_SC_ERR_VERSION */
  69        -EINVAL, /* IMX_SC_ERR_CONFIG */
  70        -EINVAL, /* IMX_SC_ERR_PARM */
  71        -EACCES, /* IMX_SC_ERR_NOACCESS */
  72        -EACCES, /* IMX_SC_ERR_LOCKED */
  73        -ERANGE, /* IMX_SC_ERR_UNAVAILABLE */
  74        -EEXIST, /* IMX_SC_ERR_NOTFOUND */
  75        -EPERM,  /* IMX_SC_ERR_NOPOWER */
  76        -EPIPE,  /* IMX_SC_ERR_IPC */
  77        -EBUSY,  /* IMX_SC_ERR_BUSY */
  78        -EIO,    /* IMX_SC_ERR_FAIL */
  79};
  80
  81static struct imx_sc_ipc *imx_sc_ipc_handle;
  82
  83static inline int imx_sc_to_linux_errno(int errno)
  84{
  85        if (errno >= IMX_SC_ERR_NONE && errno < IMX_SC_ERR_LAST)
  86                return imx_sc_linux_errmap[errno];
  87        return -EIO;
  88}
  89
  90/*
  91 * Get the default handle used by SCU
  92 */
  93int imx_scu_get_handle(struct imx_sc_ipc **ipc)
  94{
  95        if (!imx_sc_ipc_handle)
  96                return -EPROBE_DEFER;
  97
  98        *ipc = imx_sc_ipc_handle;
  99        return 0;
 100}
 101EXPORT_SYMBOL(imx_scu_get_handle);
 102
 103static void imx_scu_rx_callback(struct mbox_client *c, void *msg)
 104{
 105        struct imx_sc_chan *sc_chan = container_of(c, struct imx_sc_chan, cl);
 106        struct imx_sc_ipc *sc_ipc = sc_chan->sc_ipc;
 107        struct imx_sc_rpc_msg *hdr;
 108        u32 *data = msg;
 109
 110        if (sc_chan->idx == 0) {
 111                hdr = msg;
 112                sc_ipc->rx_size = hdr->size;
 113                dev_dbg(sc_ipc->dev, "msg rx size %u\n", sc_ipc->rx_size);
 114                if (sc_ipc->rx_size > 4)
 115                        dev_warn(sc_ipc->dev, "RPC does not support receiving over 4 words: %u\n",
 116                                 sc_ipc->rx_size);
 117        }
 118
 119        sc_ipc->msg[sc_chan->idx] = *data;
 120        sc_ipc->count++;
 121
 122        dev_dbg(sc_ipc->dev, "mu %u msg %u 0x%x\n", sc_chan->idx,
 123                sc_ipc->count, *data);
 124
 125        if ((sc_ipc->rx_size != 0) && (sc_ipc->count == sc_ipc->rx_size))
 126                complete(&sc_ipc->done);
 127}
 128
 129static int imx_scu_ipc_write(struct imx_sc_ipc *sc_ipc, void *msg)
 130{
 131        struct imx_sc_rpc_msg *hdr = msg;
 132        struct imx_sc_chan *sc_chan;
 133        u32 *data = msg;
 134        int ret;
 135        int i;
 136
 137        /* Check size */
 138        if (hdr->size > IMX_SC_RPC_MAX_MSG)
 139                return -EINVAL;
 140
 141        dev_dbg(sc_ipc->dev, "RPC SVC %u FUNC %u SIZE %u\n", hdr->svc,
 142                hdr->func, hdr->size);
 143
 144        for (i = 0; i < hdr->size; i++) {
 145                sc_chan = &sc_ipc->chans[i % 4];
 146                ret = mbox_send_message(sc_chan->ch, &data[i]);
 147                if (ret < 0)
 148                        return ret;
 149        }
 150
 151        return 0;
 152}
 153
 154/*
 155 * RPC command/response
 156 */
 157int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)
 158{
 159        struct imx_sc_rpc_msg *hdr;
 160        int ret;
 161
 162        if (WARN_ON(!sc_ipc || !msg))
 163                return -EINVAL;
 164
 165        mutex_lock(&sc_ipc->lock);
 166        reinit_completion(&sc_ipc->done);
 167
 168        sc_ipc->msg = msg;
 169        sc_ipc->count = 0;
 170        ret = imx_scu_ipc_write(sc_ipc, msg);
 171        if (ret < 0) {
 172                dev_err(sc_ipc->dev, "RPC send msg failed: %d\n", ret);
 173                goto out;
 174        }
 175
 176        if (have_resp) {
 177                if (!wait_for_completion_timeout(&sc_ipc->done,
 178                                                 MAX_RX_TIMEOUT)) {
 179                        dev_err(sc_ipc->dev, "RPC send msg timeout\n");
 180                        mutex_unlock(&sc_ipc->lock);
 181                        return -ETIMEDOUT;
 182                }
 183
 184                /* response status is stored in hdr->func field */
 185                hdr = msg;
 186                ret = hdr->func;
 187        }
 188
 189out:
 190        mutex_unlock(&sc_ipc->lock);
 191
 192        dev_dbg(sc_ipc->dev, "RPC SVC done\n");
 193
 194        return imx_sc_to_linux_errno(ret);
 195}
 196EXPORT_SYMBOL(imx_scu_call_rpc);
 197
 198static int imx_scu_probe(struct platform_device *pdev)
 199{
 200        struct device *dev = &pdev->dev;
 201        struct imx_sc_ipc *sc_ipc;
 202        struct imx_sc_chan *sc_chan;
 203        struct mbox_client *cl;
 204        char *chan_name;
 205        int ret;
 206        int i;
 207
 208        sc_ipc = devm_kzalloc(dev, sizeof(*sc_ipc), GFP_KERNEL);
 209        if (!sc_ipc)
 210                return -ENOMEM;
 211
 212        for (i = 0; i < SCU_MU_CHAN_NUM; i++) {
 213                if (i < 4)
 214                        chan_name = kasprintf(GFP_KERNEL, "tx%d", i);
 215                else
 216                        chan_name = kasprintf(GFP_KERNEL, "rx%d", i - 4);
 217
 218                if (!chan_name)
 219                        return -ENOMEM;
 220
 221                sc_chan = &sc_ipc->chans[i];
 222                cl = &sc_chan->cl;
 223                cl->dev = dev;
 224                cl->tx_block = false;
 225                cl->knows_txdone = true;
 226                cl->rx_callback = imx_scu_rx_callback;
 227
 228                sc_chan->sc_ipc = sc_ipc;
 229                sc_chan->idx = i % 4;
 230                sc_chan->ch = mbox_request_channel_byname(cl, chan_name);
 231                if (IS_ERR(sc_chan->ch)) {
 232                        ret = PTR_ERR(sc_chan->ch);
 233                        if (ret != -EPROBE_DEFER)
 234                                dev_err(dev, "Failed to request mbox chan %s ret %d\n",
 235                                        chan_name, ret);
 236                        return ret;
 237                }
 238
 239                dev_dbg(dev, "request mbox chan %s\n", chan_name);
 240                /* chan_name is not used anymore by framework */
 241                kfree(chan_name);
 242        }
 243
 244        sc_ipc->dev = dev;
 245        mutex_init(&sc_ipc->lock);
 246        init_completion(&sc_ipc->done);
 247
 248        imx_sc_ipc_handle = sc_ipc;
 249
 250        ret = imx_scu_enable_general_irq_channel(dev);
 251        if (ret)
 252                dev_warn(dev,
 253                        "failed to enable general irq channel: %d\n", ret);
 254
 255        dev_info(dev, "NXP i.MX SCU Initialized\n");
 256
 257        return devm_of_platform_populate(dev);
 258}
 259
 260static const struct of_device_id imx_scu_match[] = {
 261        { .compatible = "fsl,imx-scu", },
 262        { /* Sentinel */ }
 263};
 264
 265static struct platform_driver imx_scu_driver = {
 266        .driver = {
 267                .name = "imx-scu",
 268                .of_match_table = imx_scu_match,
 269        },
 270        .probe = imx_scu_probe,
 271};
 272builtin_platform_driver(imx_scu_driver);
 273
 274MODULE_AUTHOR("Dong Aisheng <aisheng.dong@nxp.com>");
 275MODULE_DESCRIPTION("IMX SCU firmware protocol driver");
 276MODULE_LICENSE("GPL v2");
 277
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