drivers/firmware/imx/imx-scu.c

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