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1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause2/*3 * AMD MP2 PCIe communication driver4 *5 * Authors: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>6 * Elie Morisse <syniurge@gmail.com>7 */8 9#include <linux/dma-mapping.h>10#include <linux/interrupt.h>11#include <linux/module.h>12#include <linux/pci.h>13#include <linux/slab.h>14 15#include "i2c-amd-mp2.h"16 17#include <linux/io-64-nonatomic-lo-hi.h>18 19static void amd_mp2_c2p_mutex_lock(struct amd_i2c_common *i2c_common)20{21 struct amd_mp2_dev *privdata = i2c_common->mp2_dev;22 23 /* there is only one data mailbox for two i2c adapters */24 mutex_lock(&privdata->c2p_lock);25 privdata->c2p_lock_busid = i2c_common->bus_id;26}27 28static void amd_mp2_c2p_mutex_unlock(struct amd_i2c_common *i2c_common)29{30 struct amd_mp2_dev *privdata = i2c_common->mp2_dev;31 32 if (unlikely(privdata->c2p_lock_busid != i2c_common->bus_id)) {33 pci_warn(privdata->pci_dev,34 "bus %d attempting to unlock C2P locked by bus %d\n",35 i2c_common->bus_id, privdata->c2p_lock_busid);36 return;37 }38 39 mutex_unlock(&privdata->c2p_lock);40}41 42static int amd_mp2_cmd(struct amd_i2c_common *i2c_common,43 union i2c_cmd_base i2c_cmd_base)44{45 struct amd_mp2_dev *privdata = i2c_common->mp2_dev;46 void __iomem *reg;47 48 i2c_common->reqcmd = i2c_cmd_base.s.i2c_cmd;49 50 reg = privdata->mmio + ((i2c_cmd_base.s.bus_id == 1) ?51 AMD_C2P_MSG1 : AMD_C2P_MSG0);52 writel(i2c_cmd_base.ul, reg);53 54 return 0;55}56 57int amd_mp2_bus_enable_set(struct amd_i2c_common *i2c_common, bool enable)58{59 struct amd_mp2_dev *privdata = i2c_common->mp2_dev;60 union i2c_cmd_base i2c_cmd_base;61 62 pci_dbg(privdata->pci_dev, "id: %d\n", i2c_common->bus_id);63 64 i2c_cmd_base.ul = 0;65 i2c_cmd_base.s.i2c_cmd = enable ? i2c_enable : i2c_disable;66 i2c_cmd_base.s.bus_id = i2c_common->bus_id;67 i2c_cmd_base.s.i2c_speed = i2c_common->i2c_speed;68 69 amd_mp2_c2p_mutex_lock(i2c_common);70 71 return amd_mp2_cmd(i2c_common, i2c_cmd_base);72}73EXPORT_SYMBOL_GPL(amd_mp2_bus_enable_set);74 75static void amd_mp2_cmd_rw_fill(struct amd_i2c_common *i2c_common,76 union i2c_cmd_base *i2c_cmd_base,77 enum i2c_cmd reqcmd)78{79 i2c_cmd_base->s.i2c_cmd = reqcmd;80 i2c_cmd_base->s.bus_id = i2c_common->bus_id;81 i2c_cmd_base->s.i2c_speed = i2c_common->i2c_speed;82 i2c_cmd_base->s.slave_addr = i2c_common->msg->addr;83 i2c_cmd_base->s.length = i2c_common->msg->len;84}85 86int amd_mp2_rw(struct amd_i2c_common *i2c_common, enum i2c_cmd reqcmd)87{88 struct amd_mp2_dev *privdata = i2c_common->mp2_dev;89 union i2c_cmd_base i2c_cmd_base;90 91 amd_mp2_cmd_rw_fill(i2c_common, &i2c_cmd_base, reqcmd);92 amd_mp2_c2p_mutex_lock(i2c_common);93 94 if (i2c_common->msg->len <= 32) {95 i2c_cmd_base.s.mem_type = use_c2pmsg;96 if (reqcmd == i2c_write)97 memcpy_toio(privdata->mmio + AMD_C2P_MSG2,98 i2c_common->msg->buf,99 i2c_common->msg->len);100 } else {101 i2c_cmd_base.s.mem_type = use_dram;102 writeq((u64)i2c_common->dma_addr,103 privdata->mmio + AMD_C2P_MSG2);104 }105 106 return amd_mp2_cmd(i2c_common, i2c_cmd_base);107}108EXPORT_SYMBOL_GPL(amd_mp2_rw);109 110static void amd_mp2_pci_check_rw_event(struct amd_i2c_common *i2c_common)111{112 struct amd_mp2_dev *privdata = i2c_common->mp2_dev;113 struct pci_dev *pdev = privdata->pci_dev;114 int len = i2c_common->eventval.r.length;115 u32 slave_addr = i2c_common->eventval.r.slave_addr;116 bool err = false;117 118 if (unlikely(len != i2c_common->msg->len)) {119 pci_err(pdev, "length %d in event doesn't match buffer length %d!\n",120 len, i2c_common->msg->len);121 err = true;122 }123 124 if (unlikely(slave_addr != i2c_common->msg->addr)) {125 pci_err(pdev, "unexpected slave address %x (expected: %x)!\n",126 slave_addr, i2c_common->msg->addr);127 err = true;128 }129 130 if (!err)131 i2c_common->cmd_success = true;132}133 134static void __amd_mp2_process_event(struct amd_i2c_common *i2c_common)135{136 struct amd_mp2_dev *privdata = i2c_common->mp2_dev;137 struct pci_dev *pdev = privdata->pci_dev;138 enum status_type sts = i2c_common->eventval.r.status;139 enum response_type res = i2c_common->eventval.r.response;140 int len = i2c_common->eventval.r.length;141 142 if (res != command_success) {143 if (res != command_failed)144 pci_err(pdev, "invalid response to i2c command!\n");145 return;146 }147 148 switch (i2c_common->reqcmd) {149 case i2c_read:150 if (sts == i2c_readcomplete_event) {151 amd_mp2_pci_check_rw_event(i2c_common);152 if (len <= 32)153 memcpy_fromio(i2c_common->msg->buf,154 privdata->mmio + AMD_C2P_MSG2,155 len);156 } else if (sts != i2c_readfail_event) {157 pci_err(pdev, "invalid i2c status after read (%d)!\n", sts);158 }159 break;160 case i2c_write:161 if (sts == i2c_writecomplete_event)162 amd_mp2_pci_check_rw_event(i2c_common);163 else if (sts != i2c_writefail_event)164 pci_err(pdev, "invalid i2c status after write (%d)!\n", sts);165 break;166 case i2c_enable:167 if (sts == i2c_busenable_complete)168 i2c_common->cmd_success = true;169 else if (sts != i2c_busenable_failed)170 pci_err(pdev, "invalid i2c status after bus enable (%d)!\n", sts);171 break;172 case i2c_disable:173 if (sts == i2c_busdisable_complete)174 i2c_common->cmd_success = true;175 else if (sts != i2c_busdisable_failed)176 pci_err(pdev, "invalid i2c status after bus disable (%d)!\n", sts);177 break;178 default:179 break;180 }181}182 183void amd_mp2_process_event(struct amd_i2c_common *i2c_common)184{185 struct amd_mp2_dev *privdata = i2c_common->mp2_dev;186 struct pci_dev *pdev = privdata->pci_dev;187 188 if (unlikely(i2c_common->reqcmd == i2c_none)) {189 pci_warn(pdev, "received msg but no cmd was sent (bus = %d)!\n",190 i2c_common->bus_id);191 return;192 }193 194 __amd_mp2_process_event(i2c_common);195 196 i2c_common->reqcmd = i2c_none;197 amd_mp2_c2p_mutex_unlock(i2c_common);198}199EXPORT_SYMBOL_GPL(amd_mp2_process_event);200 201static irqreturn_t amd_mp2_irq_isr(int irq, void *dev)202{203 struct amd_mp2_dev *privdata = dev;204 struct pci_dev *pdev = privdata->pci_dev;205 struct amd_i2c_common *i2c_common;206 u32 val;207 unsigned int bus_id;208 void __iomem *reg;209 enum irqreturn ret = IRQ_NONE;210 211 for (bus_id = 0; bus_id < 2; bus_id++) {212 i2c_common = privdata->busses[bus_id];213 if (!i2c_common)214 continue;215 216 reg = privdata->mmio + ((bus_id == 0) ?217 AMD_P2C_MSG1 : AMD_P2C_MSG2);218 val = readl(reg);219 if (val != 0) {220 writel(0, reg);221 writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);222 i2c_common->eventval.ul = val;223 i2c_common->cmd_completion(i2c_common);224 225 ret = IRQ_HANDLED;226 }227 }228 229 if (ret != IRQ_HANDLED) {230 val = readl(privdata->mmio + AMD_P2C_MSG_INTEN);231 if (val != 0) {232 writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);233 pci_warn(pdev, "received irq without message\n");234 ret = IRQ_HANDLED;235 }236 }237 238 return ret;239}240 241void amd_mp2_rw_timeout(struct amd_i2c_common *i2c_common)242{243 i2c_common->reqcmd = i2c_none;244 amd_mp2_c2p_mutex_unlock(i2c_common);245}246EXPORT_SYMBOL_GPL(amd_mp2_rw_timeout);247 248int amd_mp2_register_cb(struct amd_i2c_common *i2c_common)249{250 struct amd_mp2_dev *privdata = i2c_common->mp2_dev;251 struct pci_dev *pdev = privdata->pci_dev;252 253 if (i2c_common->bus_id > 1)254 return -EINVAL;255 256 if (privdata->busses[i2c_common->bus_id]) {257 pci_err(pdev, "Bus %d already taken!\n", i2c_common->bus_id);258 return -EINVAL;259 }260 261 privdata->busses[i2c_common->bus_id] = i2c_common;262 263 return 0;264}265EXPORT_SYMBOL_GPL(amd_mp2_register_cb);266 267int amd_mp2_unregister_cb(struct amd_i2c_common *i2c_common)268{269 struct amd_mp2_dev *privdata = i2c_common->mp2_dev;270 271 privdata->busses[i2c_common->bus_id] = NULL;272 273 return 0;274}275EXPORT_SYMBOL_GPL(amd_mp2_unregister_cb);276 277static void amd_mp2_clear_reg(struct amd_mp2_dev *privdata)278{279 int reg;280 281 for (reg = AMD_C2P_MSG0; reg <= AMD_C2P_MSG9; reg += 4)282 writel(0, privdata->mmio + reg);283 284 for (reg = AMD_P2C_MSG1; reg <= AMD_P2C_MSG2; reg += 4)285 writel(0, privdata->mmio + reg);286}287 288static int amd_mp2_pci_init(struct amd_mp2_dev *privdata,289 struct pci_dev *pci_dev)290{291 int irq_flag = 0, rc;292 293 pci_set_drvdata(pci_dev, privdata);294 295 rc = pcim_enable_device(pci_dev);296 if (rc) {297 pci_err(pci_dev, "Failed to enable MP2 PCI device\n");298 goto err_pci_enable;299 }300 301 rc = pcim_iomap_regions(pci_dev, 1 << 2, pci_name(pci_dev));302 if (rc) {303 pci_err(pci_dev, "I/O memory remapping failed\n");304 goto err_pci_enable;305 }306 privdata->mmio = pcim_iomap_table(pci_dev)[2];307 308 pci_set_master(pci_dev);309 310 rc = dma_set_mask(&pci_dev->dev, DMA_BIT_MASK(64));311 if (rc)312 goto err_dma_mask;313 314 /* request and enable interrupt */315 writel(0, privdata->mmio + AMD_P2C_MSG_INTEN);316 rc = pci_alloc_irq_vectors(pci_dev, 1, 1, PCI_IRQ_ALL_TYPES);317 if (rc < 0) {318 dev_err(&pci_dev->dev, "Failed to allocate single IRQ err=%d\n", rc);319 goto err_dma_mask;320 }321 322 privdata->dev_irq = pci_irq_vector(pci_dev, 0);323 if (!pci_dev->msix_enabled && !pci_dev->msi_enabled)324 irq_flag = IRQF_SHARED;325 326 rc = devm_request_irq(&pci_dev->dev, privdata->dev_irq,327 amd_mp2_irq_isr, irq_flag, dev_name(&pci_dev->dev), privdata);328 if (rc) {329 pci_err(pci_dev, "Failure requesting irq %i: %d\n", privdata->dev_irq, rc);330 goto free_irq_vectors;331 }332 333 return rc;334 335free_irq_vectors:336 free_irq(privdata->dev_irq, privdata);337err_dma_mask:338 pci_clear_master(pci_dev);339err_pci_enable:340 pci_set_drvdata(pci_dev, NULL);341 return rc;342}343 344static int amd_mp2_pci_probe(struct pci_dev *pci_dev,345 const struct pci_device_id *id)346{347 struct amd_mp2_dev *privdata;348 int rc;349 350 privdata = devm_kzalloc(&pci_dev->dev, sizeof(*privdata), GFP_KERNEL);351 if (!privdata)352 return -ENOMEM;353 354 privdata->pci_dev = pci_dev;355 rc = amd_mp2_pci_init(privdata, pci_dev);356 if (rc)357 return rc;358 359 mutex_init(&privdata->c2p_lock);360 361 pm_runtime_set_autosuspend_delay(&pci_dev->dev, 1000);362 pm_runtime_use_autosuspend(&pci_dev->dev);363 pm_runtime_put_autosuspend(&pci_dev->dev);364 pm_runtime_allow(&pci_dev->dev);365 366 privdata->probed = true;367 368 pci_info(pci_dev, "MP2 device registered.\n");369 return 0;370}371 372static void amd_mp2_pci_remove(struct pci_dev *pci_dev)373{374 struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev);375 376 pm_runtime_forbid(&pci_dev->dev);377 pm_runtime_get_noresume(&pci_dev->dev);378 379 free_irq(privdata->dev_irq, privdata);380 pci_clear_master(pci_dev);381 382 amd_mp2_clear_reg(privdata);383}384 385#ifdef CONFIG_PM386static int amd_mp2_pci_suspend(struct device *dev)387{388 struct pci_dev *pci_dev = to_pci_dev(dev);389 struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev);390 struct amd_i2c_common *i2c_common;391 unsigned int bus_id;392 int ret = 0;393 394 for (bus_id = 0; bus_id < 2; bus_id++) {395 i2c_common = privdata->busses[bus_id];396 if (i2c_common)397 i2c_common->suspend(i2c_common);398 }399 400 ret = pci_save_state(pci_dev);401 if (ret) {402 pci_err(pci_dev, "pci_save_state failed = %d\n", ret);403 return ret;404 }405 406 pci_disable_device(pci_dev);407 return ret;408}409 410static int amd_mp2_pci_resume(struct device *dev)411{412 struct pci_dev *pci_dev = to_pci_dev(dev);413 struct amd_mp2_dev *privdata = pci_get_drvdata(pci_dev);414 struct amd_i2c_common *i2c_common;415 unsigned int bus_id;416 int ret = 0;417 418 pci_restore_state(pci_dev);419 ret = pci_enable_device(pci_dev);420 if (ret < 0) {421 pci_err(pci_dev, "pci_enable_device failed = %d\n", ret);422 return ret;423 }424 425 for (bus_id = 0; bus_id < 2; bus_id++) {426 i2c_common = privdata->busses[bus_id];427 if (i2c_common) {428 ret = i2c_common->resume(i2c_common);429 if (ret < 0)430 return ret;431 }432 }433 434 return ret;435}436 437static UNIVERSAL_DEV_PM_OPS(amd_mp2_pci_pm_ops, amd_mp2_pci_suspend,438 amd_mp2_pci_resume, NULL);439#endif /* CONFIG_PM */440 441static const struct pci_device_id amd_mp2_pci_tbl[] = {442 {PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_MP2)},443 {0}444};445MODULE_DEVICE_TABLE(pci, amd_mp2_pci_tbl);446 447static struct pci_driver amd_mp2_pci_driver = {448 .name = "i2c_amd_mp2",449 .id_table = amd_mp2_pci_tbl,450 .probe = amd_mp2_pci_probe,451 .remove = amd_mp2_pci_remove,452#ifdef CONFIG_PM453 .driver = {454 .pm = &amd_mp2_pci_pm_ops,455 },456#endif457};458module_pci_driver(amd_mp2_pci_driver);459 460struct amd_mp2_dev *amd_mp2_find_device(void)461{462 struct device *dev;463 struct pci_dev *pci_dev;464 465 dev = driver_find_next_device(&amd_mp2_pci_driver.driver, NULL);466 if (!dev)467 return NULL;468 469 pci_dev = to_pci_dev(dev);470 return (struct amd_mp2_dev *)pci_get_drvdata(pci_dev);471}472EXPORT_SYMBOL_GPL(amd_mp2_find_device);473 474MODULE_DESCRIPTION("AMD(R) PCI-E MP2 I2C Controller Driver");475MODULE_AUTHOR("Shyam Sundar S K <Shyam-sundar.S-k@amd.com>");476MODULE_AUTHOR("Elie Morisse <syniurge@gmail.com>");477MODULE_LICENSE("Dual BSD/GPL");478