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/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
  26 struct 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
  34 struct 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  */
  50 enum 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
  66 static 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
  81 static struct imx_sc_ipc *imx_sc_ipc_handle;
  82
  83 static 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  */
  93 int 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 }
 101 EXPORT_SYMBOL(imx_scu_get_handle);
 102
 103 static 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_ipc->msg) {
 111                 dev_warn(sc_ipc->dev, "unexpected rx idx %d 0x%08x, ignore!\n",
 112                                 sc_chan->idx, *data);
 113                 return;
 114         }
 115
 116         if (sc_chan->idx == 0) {
 117                 hdr = msg;
 118                 sc_ipc->rx_size = hdr->size;
 119                 dev_dbg(sc_ipc->dev, "msg rx size %u\n", sc_ipc->rx_size);
 120                 if (sc_ipc->rx_size > 4)
 121                         dev_warn(sc_ipc->dev, "RPC does not support receiving over 4 words: %u\n",
 122                                  sc_ipc->rx_size);
 123         }
 124
 125         sc_ipc->msg[sc_chan->idx] = *data;
 126         sc_ipc->count++;
 127
 128         dev_dbg(sc_ipc->dev, "mu %u msg %u 0x%x\n", sc_chan->idx,
 129                 sc_ipc->count, *data);
 130
 131         if ((sc_ipc->rx_size != 0) && (sc_ipc->count == sc_ipc->rx_size))
 132                 complete(&sc_ipc->done);
 133 }
 134
 135 static int imx_scu_ipc_write(struct imx_sc_ipc *sc_ipc, void *msg)
 136 {
 137         struct imx_sc_rpc_msg *hdr = msg;
 138         struct imx_sc_chan *sc_chan;
 139         u32 *data = msg;
 140         int ret;
 141         int i;
 142
 143         /* Check size */
 144         if (hdr->size > IMX_SC_RPC_MAX_MSG)
 145                 return -EINVAL;
 146
 147         dev_dbg(sc_ipc->dev, "RPC SVC %u FUNC %u SIZE %u\n", hdr->svc,
 148                 hdr->func, hdr->size);
 149
 150         for (i = 0; i < hdr->size; i++) {
 151                 sc_chan = &sc_ipc->chans[i % 4];
 152                 ret = mbox_send_message(sc_chan->ch, &data[i]);
 153                 if (ret < 0)
 154                         return ret;
 155         }
 156
 157         return 0;
 158 }
 159
 160 /*
 161  * RPC command/response
 162  */
 163 int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)
 164 {
 165         uint8_t saved_svc, saved_func;
 166         struct imx_sc_rpc_msg *hdr;
 167         int ret;
 168
 169         if (WARN_ON(!sc_ipc || !msg))
 170                 return -EINVAL;
 171
 172         mutex_lock(&sc_ipc->lock);
 173         reinit_completion(&sc_ipc->done);
 174
 175         if (have_resp) {
 176                 sc_ipc->msg = msg;
 177                 saved_svc = ((struct imx_sc_rpc_msg *)msg)->svc;
 178                 saved_func = ((struct imx_sc_rpc_msg *)msg)->func;
 179         }
 180         sc_ipc->count = 0;
 181         ret = imx_scu_ipc_write(sc_ipc, msg);
 182         if (ret < 0) {
 183                 dev_err(sc_ipc->dev, "RPC send msg failed: %d\n", ret);
 184                 goto out;
 185         }
 186
 187         if (have_resp) {
 188                 if (!wait_for_completion_timeout(&sc_ipc->done,
 189                                                  MAX_RX_TIMEOUT)) {
 190                         dev_err(sc_ipc->dev, "RPC send msg timeout\n");
 191                         mutex_unlock(&sc_ipc->lock);
 192                         return -ETIMEDOUT;
 193                 }
 194
 195                 /* response status is stored in hdr->func field */
 196                 hdr = msg;
 197                 ret = hdr->func;
 198                 /*
 199                  * Some special SCU firmware APIs do NOT have return value
 200                  * in hdr->func, but they do have response data, those special
 201                  * APIs are defined as void function in SCU firmware, so they
 202                  * should be treated as return success always.
 203                  */
 204                 if ((saved_svc == IMX_SC_RPC_SVC_MISC) &&
 205                         (saved_func == IMX_SC_MISC_FUNC_UNIQUE_ID ||
 206                          saved_func == IMX_SC_MISC_FUNC_GET_BUTTON_STATUS))
 207                         ret = 0;
 208         }
 209
 210 out:
 211         sc_ipc->msg = NULL;
 212         mutex_unlock(&sc_ipc->lock);
 213
 214         dev_dbg(sc_ipc->dev, "RPC SVC done\n");
 215
 216         return imx_sc_to_linux_errno(ret);
 217 }
 218 EXPORT_SYMBOL(imx_scu_call_rpc);
 219
 220 static int imx_scu_probe(struct platform_device *pdev)
 221 {
 222         struct device *dev = &pdev->dev;
 223         struct imx_sc_ipc *sc_ipc;
 224         struct imx_sc_chan *sc_chan;
 225         struct mbox_client *cl;
 226         char *chan_name;
 227         int ret;
 228         int i;
 229
 230         sc_ipc = devm_kzalloc(dev, sizeof(*sc_ipc), GFP_KERNEL);
 231         if (!sc_ipc)
 232                 return -ENOMEM;
 233
 234         for (i = 0; i < SCU_MU_CHAN_NUM; i++) {
 235                 if (i < 4)
 236                         chan_name = kasprintf(GFP_KERNEL, "tx%d", i);
 237                 else
 238                         chan_name = kasprintf(GFP_KERNEL, "rx%d", i - 4);
 239
 240                 if (!chan_name)
 241                         return -ENOMEM;
 242
 243                 sc_chan = &sc_ipc->chans[i];
 244                 cl = &sc_chan->cl;
 245                 cl->dev = dev;
 246                 cl->tx_block = false;
 247                 cl->knows_txdone = true;
 248                 cl->rx_callback = imx_scu_rx_callback;
 249
 250                 sc_chan->sc_ipc = sc_ipc;
 251                 sc_chan->idx = i % 4;
 252                 sc_chan->ch = mbox_request_channel_byname(cl, chan_name);
 253                 if (IS_ERR(sc_chan->ch)) {
 254                         ret = PTR_ERR(sc_chan->ch);
 255                         if (ret != -EPROBE_DEFER)
 256                                 dev_err(dev, "Failed to request mbox chan %s ret %d\n",
 257                                         chan_name, ret);
 258                         return ret;
 259                 }
 260
 261                 dev_dbg(dev, "request mbox chan %s\n", chan_name);
 262                 /* chan_name is not used anymore by framework */
 263                 kfree(chan_name);
 264         }
 265
 266         sc_ipc->dev = dev;
 267         mutex_init(&sc_ipc->lock);
 268         init_completion(&sc_ipc->done);
 269
 270         imx_sc_ipc_handle = sc_ipc;
 271
 272         ret = imx_scu_enable_general_irq_channel(dev);
 273         if (ret)
 274                 dev_warn(dev,
 275                         "failed to enable general irq channel: %d\n", ret);
 276
 277         dev_info(dev, "NXP i.MX SCU Initialized\n");
 278
 279         return devm_of_platform_populate(dev);
 280 }
 281
 282 static const struct of_device_id imx_scu_match[] = {
 283         { .compatible = "fsl,imx-scu", },
 284         { /* Sentinel */ }
 285 };
 286
 287 static struct platform_driver imx_scu_driver = {
 288         .driver = {
 289                 .name = "imx-scu",
 290                 .of_match_table = imx_scu_match,
 291         },
 292         .probe = imx_scu_probe,
 293 };
 294 builtin_platform_driver(imx_scu_driver);
 295
 296 MODULE_AUTHOR("Dong Aisheng <aisheng.dong@nxp.com>");
 297 MODULE_DESCRIPTION("IMX SCU firmware protocol driver");
 298 MODULE_LICENSE("GPL v2");