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1// SPDX-License-Identifier: GPL-2.0+2/*3 * Copyright 2018 NXP4 * 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/ipc.h>12#include <linux/firmware/imx/sci.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.h>20#include <linux/of_platform.h>21#include <linux/platform_device.h>22 23#define SCU_MU_CHAN_NUM 824#define MAX_RX_TIMEOUT (msecs_to_jiffies(3000))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 struct completion tx_done;33};34 35struct imx_sc_ipc {36 /* SCU uses 4 Tx and 4 Rx channels */37 struct imx_sc_chan chans[SCU_MU_CHAN_NUM];38 struct device *dev;39 struct mutex lock;40 struct completion done;41 bool fast_ipc;42 43 /* temporarily store the SCU msg */44 u32 *msg;45 u8 rx_size;46 u8 count;47};48 49/*50 * This type is used to indicate error response for most functions.51 */52enum imx_sc_error_codes {53 IMX_SC_ERR_NONE = 0, /* Success */54 IMX_SC_ERR_VERSION = 1, /* Incompatible API version */55 IMX_SC_ERR_CONFIG = 2, /* Configuration error */56 IMX_SC_ERR_PARM = 3, /* Bad parameter */57 IMX_SC_ERR_NOACCESS = 4, /* Permission error (no access) */58 IMX_SC_ERR_LOCKED = 5, /* Permission error (locked) */59 IMX_SC_ERR_UNAVAILABLE = 6, /* Unavailable (out of resources) */60 IMX_SC_ERR_NOTFOUND = 7, /* Not found */61 IMX_SC_ERR_NOPOWER = 8, /* No power */62 IMX_SC_ERR_IPC = 9, /* Generic IPC error */63 IMX_SC_ERR_BUSY = 10, /* Resource is currently busy/active */64 IMX_SC_ERR_FAIL = 11, /* General I/O failure */65 IMX_SC_ERR_LAST66};67 68static int imx_sc_linux_errmap[IMX_SC_ERR_LAST] = {69 0, /* IMX_SC_ERR_NONE */70 -EINVAL, /* IMX_SC_ERR_VERSION */71 -EINVAL, /* IMX_SC_ERR_CONFIG */72 -EINVAL, /* IMX_SC_ERR_PARM */73 -EACCES, /* IMX_SC_ERR_NOACCESS */74 -EACCES, /* IMX_SC_ERR_LOCKED */75 -ERANGE, /* IMX_SC_ERR_UNAVAILABLE */76 -EEXIST, /* IMX_SC_ERR_NOTFOUND */77 -EPERM, /* IMX_SC_ERR_NOPOWER */78 -EPIPE, /* IMX_SC_ERR_IPC */79 -EBUSY, /* IMX_SC_ERR_BUSY */80 -EIO, /* IMX_SC_ERR_FAIL */81};82 83static struct imx_sc_ipc *imx_sc_ipc_handle;84 85static inline int imx_sc_to_linux_errno(int errno)86{87 if (errno >= IMX_SC_ERR_NONE && errno < IMX_SC_ERR_LAST)88 return imx_sc_linux_errmap[errno];89 return -EIO;90}91 92/*93 * Get the default handle used by SCU94 */95int imx_scu_get_handle(struct imx_sc_ipc **ipc)96{97 if (!imx_sc_ipc_handle)98 return -EPROBE_DEFER;99 100 *ipc = imx_sc_ipc_handle;101 return 0;102}103EXPORT_SYMBOL(imx_scu_get_handle);104 105/* Callback called when the word of a message is ack-ed, eg read by SCU */106static void imx_scu_tx_done(struct mbox_client *cl, void *mssg, int r)107{108 struct imx_sc_chan *sc_chan = container_of(cl, struct imx_sc_chan, cl);109 110 complete(&sc_chan->tx_done);111}112 113static void imx_scu_rx_callback(struct mbox_client *c, void *msg)114{115 struct imx_sc_chan *sc_chan = container_of(c, struct imx_sc_chan, cl);116 struct imx_sc_ipc *sc_ipc = sc_chan->sc_ipc;117 struct imx_sc_rpc_msg *hdr;118 u32 *data = msg;119 int i;120 121 if (!sc_ipc->msg) {122 dev_warn(sc_ipc->dev, "unexpected rx idx %d 0x%08x, ignore!\n",123 sc_chan->idx, *data);124 return;125 }126 127 if (sc_ipc->fast_ipc) {128 hdr = msg;129 sc_ipc->rx_size = hdr->size;130 sc_ipc->msg[0] = *data++;131 132 for (i = 1; i < sc_ipc->rx_size; i++)133 sc_ipc->msg[i] = *data++;134 135 complete(&sc_ipc->done);136 137 return;138 }139 140 if (sc_chan->idx == 0) {141 hdr = msg;142 sc_ipc->rx_size = hdr->size;143 dev_dbg(sc_ipc->dev, "msg rx size %u\n", sc_ipc->rx_size);144 if (sc_ipc->rx_size > 4)145 dev_warn(sc_ipc->dev, "RPC does not support receiving over 4 words: %u\n",146 sc_ipc->rx_size);147 }148 149 sc_ipc->msg[sc_chan->idx] = *data;150 sc_ipc->count++;151 152 dev_dbg(sc_ipc->dev, "mu %u msg %u 0x%x\n", sc_chan->idx,153 sc_ipc->count, *data);154 155 if ((sc_ipc->rx_size != 0) && (sc_ipc->count == sc_ipc->rx_size))156 complete(&sc_ipc->done);157}158 159static int imx_scu_ipc_write(struct imx_sc_ipc *sc_ipc, void *msg)160{161 struct imx_sc_rpc_msg hdr = *(struct imx_sc_rpc_msg *)msg;162 struct imx_sc_chan *sc_chan;163 u32 *data = msg;164 int ret;165 int size;166 int i;167 168 /* Check size */169 if (hdr.size > IMX_SC_RPC_MAX_MSG)170 return -EINVAL;171 172 dev_dbg(sc_ipc->dev, "RPC SVC %u FUNC %u SIZE %u\n", hdr.svc,173 hdr.func, hdr.size);174 175 size = sc_ipc->fast_ipc ? 1 : hdr.size;176 for (i = 0; i < size; i++) {177 sc_chan = &sc_ipc->chans[i % 4];178 179 /*180 * SCU requires that all messages words are written181 * sequentially but linux MU driver implements multiple182 * independent channels for each register so ordering between183 * different channels must be ensured by SCU API interface.184 *185 * Wait for tx_done before every send to ensure that no186 * queueing happens at the mailbox channel level.187 */188 if (!sc_ipc->fast_ipc) {189 wait_for_completion(&sc_chan->tx_done);190 reinit_completion(&sc_chan->tx_done);191 }192 193 ret = mbox_send_message(sc_chan->ch, &data[i]);194 if (ret < 0)195 return ret;196 }197 198 return 0;199}200 201/*202 * RPC command/response203 */204int imx_scu_call_rpc(struct imx_sc_ipc *sc_ipc, void *msg, bool have_resp)205{206 uint8_t saved_svc, saved_func;207 struct imx_sc_rpc_msg *hdr;208 int ret;209 210 if (WARN_ON(!sc_ipc || !msg))211 return -EINVAL;212 213 mutex_lock(&sc_ipc->lock);214 reinit_completion(&sc_ipc->done);215 216 if (have_resp) {217 sc_ipc->msg = msg;218 saved_svc = ((struct imx_sc_rpc_msg *)msg)->svc;219 saved_func = ((struct imx_sc_rpc_msg *)msg)->func;220 }221 sc_ipc->count = 0;222 ret = imx_scu_ipc_write(sc_ipc, msg);223 if (ret < 0) {224 dev_err(sc_ipc->dev, "RPC send msg failed: %d\n", ret);225 goto out;226 }227 228 if (have_resp) {229 if (!wait_for_completion_timeout(&sc_ipc->done,230 MAX_RX_TIMEOUT)) {231 dev_err(sc_ipc->dev, "RPC send msg timeout\n");232 mutex_unlock(&sc_ipc->lock);233 return -ETIMEDOUT;234 }235 236 /* response status is stored in hdr->func field */237 hdr = msg;238 ret = hdr->func;239 /*240 * Some special SCU firmware APIs do NOT have return value241 * in hdr->func, but they do have response data, those special242 * APIs are defined as void function in SCU firmware, so they243 * should be treated as return success always.244 */245 if ((saved_svc == IMX_SC_RPC_SVC_MISC) &&246 (saved_func == IMX_SC_MISC_FUNC_UNIQUE_ID ||247 saved_func == IMX_SC_MISC_FUNC_GET_BUTTON_STATUS))248 ret = 0;249 }250 251out:252 sc_ipc->msg = NULL;253 mutex_unlock(&sc_ipc->lock);254 255 dev_dbg(sc_ipc->dev, "RPC SVC done\n");256 257 return imx_sc_to_linux_errno(ret);258}259EXPORT_SYMBOL(imx_scu_call_rpc);260 261static int imx_scu_probe(struct platform_device *pdev)262{263 struct device *dev = &pdev->dev;264 struct imx_sc_ipc *sc_ipc;265 struct imx_sc_chan *sc_chan;266 struct mbox_client *cl;267 char *chan_name;268 struct of_phandle_args args;269 int num_channel;270 int ret;271 int i;272 273 sc_ipc = devm_kzalloc(dev, sizeof(*sc_ipc), GFP_KERNEL);274 if (!sc_ipc)275 return -ENOMEM;276 277 ret = of_parse_phandle_with_args(pdev->dev.of_node, "mboxes",278 "#mbox-cells", 0, &args);279 if (ret)280 return ret;281 282 sc_ipc->fast_ipc = of_device_is_compatible(args.np, "fsl,imx8-mu-scu");283 284 num_channel = sc_ipc->fast_ipc ? 2 : SCU_MU_CHAN_NUM;285 for (i = 0; i < num_channel; i++) {286 if (i < num_channel / 2)287 chan_name = kasprintf(GFP_KERNEL, "tx%d", i);288 else289 chan_name = kasprintf(GFP_KERNEL, "rx%d",290 i - num_channel / 2);291 292 if (!chan_name)293 return -ENOMEM;294 295 sc_chan = &sc_ipc->chans[i];296 cl = &sc_chan->cl;297 cl->dev = dev;298 cl->tx_block = false;299 cl->knows_txdone = true;300 cl->rx_callback = imx_scu_rx_callback;301 302 if (!sc_ipc->fast_ipc) {303 /* Initial tx_done completion as "done" */304 cl->tx_done = imx_scu_tx_done;305 init_completion(&sc_chan->tx_done);306 complete(&sc_chan->tx_done);307 }308 309 sc_chan->sc_ipc = sc_ipc;310 sc_chan->idx = i % (num_channel / 2);311 sc_chan->ch = mbox_request_channel_byname(cl, chan_name);312 if (IS_ERR(sc_chan->ch)) {313 ret = PTR_ERR(sc_chan->ch);314 dev_err_probe(dev, ret, "Failed to request mbox chan %s\n",315 chan_name);316 kfree(chan_name);317 return ret;318 }319 320 dev_dbg(dev, "request mbox chan %s\n", chan_name);321 /* chan_name is not used anymore by framework */322 kfree(chan_name);323 }324 325 sc_ipc->dev = dev;326 mutex_init(&sc_ipc->lock);327 init_completion(&sc_ipc->done);328 329 imx_sc_ipc_handle = sc_ipc;330 331 ret = imx_scu_soc_init(dev);332 if (ret)333 dev_warn(dev, "failed to initialize SoC info: %d\n", ret);334 335 ret = imx_scu_enable_general_irq_channel(dev);336 if (ret)337 dev_warn(dev,338 "failed to enable general irq channel: %d\n", ret);339 340 dev_info(dev, "NXP i.MX SCU Initialized\n");341 342 return devm_of_platform_populate(dev);343}344 345static const struct of_device_id imx_scu_match[] = {346 { .compatible = "fsl,imx-scu", },347 { /* Sentinel */ }348};349 350static struct platform_driver imx_scu_driver = {351 .driver = {352 .name = "imx-scu",353 .of_match_table = imx_scu_match,354 },355 .probe = imx_scu_probe,356};357 358static int __init imx_scu_driver_init(void)359{360 return platform_driver_register(&imx_scu_driver);361}362subsys_initcall_sync(imx_scu_driver_init);363 364MODULE_AUTHOR("Dong Aisheng <aisheng.dong@nxp.com>");365MODULE_DESCRIPTION("IMX SCU firmware protocol driver");366MODULE_LICENSE("GPL v2");367