1 // SPDX-License-Identifier: GPL-2.0 OR MIT 2 /* 3 * Intel Xe I2C attached Microcontroller Units (MCU) 4 * 5 * Copyright (C) 2025 Intel Corporation. 6 */ 7 8 #include <drm/drm_print.h> 9 #include <linux/array_size.h> 10 #include <linux/container_of.h> 11 #include <linux/device.h> 12 #include <linux/err.h> 13 #include <linux/i2c.h> 14 #include <linux/ioport.h> 15 #include <linux/irq.h> 16 #include <linux/irqdomain.h> 17 #include <linux/notifier.h> 18 #include <linux/pci.h> 19 #include <linux/platform_device.h> 20 #include <linux/property.h> 21 #include <linux/regmap.h> 22 #include <linux/sprintf.h> 23 #include <linux/string.h> 24 #include <linux/types.h> 25 #include <linux/workqueue.h> 26 27 #include "regs/xe_i2c_regs.h" 28 #include "regs/xe_irq_regs.h" 29 30 #include "xe_device.h" 31 #include "xe_i2c.h" 32 #include "xe_mmio.h" 33 #include "xe_sriov.h" 34 #include "xe_survivability_mode.h" 35 36 /** 37 * DOC: Xe I2C devices 38 * 39 * Register a platform device for the I2C host controller (Synpsys DesignWare 40 * I2C) if the registers of that controller are mapped to the MMIO, and also the 41 * I2C client device for the Add-In Management Controller (the MCU) attached to 42 * the host controller. 43 * 44 * See drivers/i2c/busses/i2c-designware-* for more information on the I2C host 45 * controller. 46 */ 47 48 static const char adapter_name[] = "i2c_designware"; 49 50 static const struct property_entry xe_i2c_adapter_properties[] = { 51 PROPERTY_ENTRY_STRING("compatible", "intel,xe-i2c"), 52 PROPERTY_ENTRY_U32("clock-frequency", I2C_MAX_FAST_MODE_PLUS_FREQ), 53 { } 54 }; 55 56 static inline void xe_i2c_read_endpoint(struct xe_mmio *mmio, void *ep) 57 { 58 u32 *val = ep; 59 60 val[0] = xe_mmio_read32(mmio, REG_SG_REMAP_ADDR_PREFIX); 61 val[1] = xe_mmio_read32(mmio, REG_SG_REMAP_ADDR_POSTFIX); 62 } 63 64 static void xe_i2c_client_work(struct work_struct *work) 65 { 66 struct xe_i2c *i2c = container_of(work, struct xe_i2c, work); 67 struct i2c_board_info info = { 68 .type = "amc", 69 .flags = I2C_CLIENT_HOST_NOTIFY, 70 .addr = i2c->ep.addr[1], 71 }; 72 73 i2c->client[0] = i2c_new_client_device(i2c->adapter, &info); 74 } 75 76 static int xe_i2c_notifier(struct notifier_block *nb, unsigned long action, void *data) 77 { 78 struct xe_i2c *i2c = container_of(nb, struct xe_i2c, bus_notifier); 79 struct i2c_adapter *adapter = i2c_verify_adapter(data); 80 struct device *dev = data; 81 82 if (action == BUS_NOTIFY_ADD_DEVICE && 83 adapter && dev->parent == &i2c->pdev->dev) { 84 i2c->adapter = adapter; 85 schedule_work(&i2c->work); 86 return NOTIFY_OK; 87 } 88 89 return NOTIFY_DONE; 90 } 91 92 static int xe_i2c_register_adapter(struct xe_i2c *i2c) 93 { 94 struct pci_dev *pci = to_pci_dev(i2c->drm_dev); 95 struct platform_device *pdev; 96 struct fwnode_handle *fwnode; 97 int ret; 98 u32 id; 99 100 fwnode = fwnode_create_software_node(xe_i2c_adapter_properties, NULL); 101 if (IS_ERR(fwnode)) 102 return PTR_ERR(fwnode); 103 104 id = (pci_domain_nr(pci->bus) << 16) | pci_dev_id(pci); 105 106 /* 107 * Not using platform_device_register_full() here because we don't have 108 * a handle to the platform_device before it returns. xe_i2c_notifier() 109 * uses that handle, but it may be called before 110 * platform_device_register_full() is done. 111 */ 112 pdev = platform_device_alloc(adapter_name, id); 113 if (!pdev) { 114 ret = -ENOMEM; 115 goto err_fwnode_remove; 116 } 117 118 if (i2c->adapter_irq) { 119 struct resource res; 120 121 res = DEFINE_RES_IRQ_NAMED(i2c->adapter_irq, "xe_i2c"); 122 123 ret = platform_device_add_resources(pdev, &res, 1); 124 if (ret) 125 goto err_pdev_put; 126 } 127 128 pdev->dev.parent = i2c->drm_dev; 129 pdev->dev.fwnode = fwnode; 130 i2c->adapter_node = fwnode; 131 i2c->pdev = pdev; 132 133 ret = platform_device_add(pdev); 134 if (ret) 135 goto err_pdev_put; 136 137 return 0; 138 139 err_pdev_put: 140 platform_device_put(pdev); 141 err_fwnode_remove: 142 fwnode_remove_software_node(fwnode); 143 144 return ret; 145 } 146 147 static void xe_i2c_unregister_adapter(struct xe_i2c *i2c) 148 { 149 platform_device_unregister(i2c->pdev); 150 fwnode_remove_software_node(i2c->adapter_node); 151 } 152 153 /** 154 * xe_i2c_present - I2C controller is present and functional 155 * @xe: xe device instance 156 * 157 * Check whether the I2C controller is present and functioning with valid 158 * endpoint cookie. 159 * 160 * Return: %true if present, %false otherwise. 161 */ 162 bool xe_i2c_present(struct xe_device *xe) 163 { 164 return xe->i2c && xe->i2c->ep.cookie == XE_I2C_EP_COOKIE_DEVICE; 165 } 166 167 static bool xe_i2c_irq_present(struct xe_device *xe) 168 { 169 return xe->i2c && xe->i2c->adapter_irq; 170 } 171 172 /** 173 * xe_i2c_irq_handler: Handler for I2C interrupts 174 * @xe: xe device instance 175 * @master_ctl: interrupt register 176 * 177 * Forward interrupts generated by the I2C host adapter to the I2C host adapter 178 * driver. 179 */ 180 void xe_i2c_irq_handler(struct xe_device *xe, u32 master_ctl) 181 { 182 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 183 184 if (!(master_ctl & I2C_IRQ) || !xe_i2c_irq_present(xe)) 185 return; 186 187 /* Forward interrupt to I2C adapter */ 188 generic_handle_irq_safe(xe->i2c->adapter_irq); 189 190 /* Deassert after I2C adapter clears the interrupt */ 191 xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, 0, PCI_COMMAND_INTX_DISABLE); 192 /* Reassert to allow subsequent interrupt generation */ 193 xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, PCI_COMMAND_INTX_DISABLE, 0); 194 } 195 196 void xe_i2c_irq_reset(struct xe_device *xe) 197 { 198 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 199 200 if (!xe_i2c_irq_present(xe)) 201 return; 202 203 xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, 0, PCI_COMMAND_INTX_DISABLE); 204 xe_mmio_rmw32(mmio, I2C_BRIDGE_PCICFGCTL, ACPI_INTR_EN, 0); 205 } 206 207 void xe_i2c_irq_postinstall(struct xe_device *xe) 208 { 209 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 210 211 if (!xe_i2c_irq_present(xe)) 212 return; 213 214 xe_mmio_rmw32(mmio, I2C_BRIDGE_PCICFGCTL, 0, ACPI_INTR_EN); 215 xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, PCI_COMMAND_INTX_DISABLE, 0); 216 } 217 218 static int xe_i2c_irq_map(struct irq_domain *h, unsigned int virq, 219 irq_hw_number_t hw_irq_num) 220 { 221 irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); 222 return 0; 223 } 224 225 static const struct irq_domain_ops xe_i2c_irq_ops = { 226 .map = xe_i2c_irq_map, 227 }; 228 229 static int xe_i2c_create_irq(struct xe_device *xe) 230 { 231 struct xe_i2c *i2c = xe->i2c; 232 struct irq_domain *domain; 233 234 if (!(i2c->ep.capabilities & XE_I2C_EP_CAP_IRQ) || 235 xe_survivability_mode_is_boot_enabled(xe)) 236 return 0; 237 238 domain = irq_domain_create_linear(dev_fwnode(i2c->drm_dev), 1, &xe_i2c_irq_ops, NULL); 239 if (!domain) 240 return -ENOMEM; 241 242 i2c->adapter_irq = irq_create_mapping(domain, 0); 243 i2c->irqdomain = domain; 244 245 return 0; 246 } 247 248 static void xe_i2c_remove_irq(struct xe_i2c *i2c) 249 { 250 if (!i2c->irqdomain) 251 return; 252 253 irq_dispose_mapping(i2c->adapter_irq); 254 irq_domain_remove(i2c->irqdomain); 255 } 256 257 static int xe_i2c_read(void *context, unsigned int reg, unsigned int *val) 258 { 259 struct xe_i2c *i2c = context; 260 261 *val = xe_mmio_read32(i2c->mmio, XE_REG(reg + I2C_MEM_SPACE_OFFSET)); 262 263 return 0; 264 } 265 266 static int xe_i2c_write(void *context, unsigned int reg, unsigned int val) 267 { 268 struct xe_i2c *i2c = context; 269 270 xe_mmio_write32(i2c->mmio, XE_REG(reg + I2C_MEM_SPACE_OFFSET), val); 271 272 return 0; 273 } 274 275 static const struct regmap_config i2c_regmap_config = { 276 .reg_bits = 32, 277 .val_bits = 32, 278 .reg_read = xe_i2c_read, 279 .reg_write = xe_i2c_write, 280 .fast_io = true, 281 }; 282 283 void xe_i2c_pm_suspend(struct xe_device *xe) 284 { 285 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 286 287 if (!xe_i2c_present(xe)) 288 return; 289 290 xe_mmio_rmw32(mmio, I2C_CONFIG_PMCSR, PCI_PM_CTRL_STATE_MASK, (__force u32)PCI_D3hot); 291 drm_dbg(&xe->drm, "pmcsr: 0x%08x\n", xe_mmio_read32(mmio, I2C_CONFIG_PMCSR)); 292 } 293 294 void xe_i2c_pm_resume(struct xe_device *xe, bool d3cold) 295 { 296 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 297 298 if (!xe_i2c_present(xe)) 299 return; 300 301 if (d3cold) 302 xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, 0, PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER); 303 304 xe_mmio_rmw32(mmio, I2C_CONFIG_PMCSR, PCI_PM_CTRL_STATE_MASK, (__force u32)PCI_D0); 305 drm_dbg(&xe->drm, "pmcsr: 0x%08x\n", xe_mmio_read32(mmio, I2C_CONFIG_PMCSR)); 306 } 307 308 static void xe_i2c_remove(void *data) 309 { 310 struct xe_i2c *i2c = data; 311 unsigned int i; 312 313 for (i = 0; i < XE_I2C_MAX_CLIENTS; i++) 314 i2c_unregister_device(i2c->client[i]); 315 316 bus_unregister_notifier(&i2c_bus_type, &i2c->bus_notifier); 317 xe_i2c_unregister_adapter(i2c); 318 xe_i2c_remove_irq(i2c); 319 } 320 321 /** 322 * xe_i2c_probe: Probe the I2C host adapter and the I2C clients attached to it 323 * @xe: xe device instance 324 * 325 * Register all the I2C devices described in the I2C Endpoint data structure. 326 * 327 * Return: 0 on success, error code on failure 328 */ 329 int xe_i2c_probe(struct xe_device *xe) 330 { 331 struct device *drm_dev = xe->drm.dev; 332 struct xe_i2c_endpoint ep; 333 struct regmap *regmap; 334 struct xe_i2c *i2c; 335 int ret; 336 337 if (!xe->info.has_i2c) 338 return 0; 339 340 if (IS_SRIOV_VF(xe)) 341 return 0; 342 343 xe_i2c_read_endpoint(xe_root_tile_mmio(xe), &ep); 344 if (ep.cookie != XE_I2C_EP_COOKIE_DEVICE) 345 return 0; 346 347 i2c = devm_kzalloc(drm_dev, sizeof(*i2c), GFP_KERNEL); 348 if (!i2c) 349 return -ENOMEM; 350 351 INIT_WORK(&i2c->work, xe_i2c_client_work); 352 i2c->mmio = xe_root_tile_mmio(xe); 353 i2c->drm_dev = drm_dev; 354 i2c->ep = ep; 355 xe->i2c = i2c; 356 357 /* PCI PM isn't aware of this device, bring it up and match it with SGUnit state. */ 358 xe_i2c_pm_resume(xe, true); 359 360 regmap = devm_regmap_init(drm_dev, NULL, i2c, &i2c_regmap_config); 361 if (IS_ERR(regmap)) 362 return PTR_ERR(regmap); 363 364 i2c->bus_notifier.notifier_call = xe_i2c_notifier; 365 ret = bus_register_notifier(&i2c_bus_type, &i2c->bus_notifier); 366 if (ret) 367 return ret; 368 369 ret = xe_i2c_create_irq(xe); 370 if (ret) 371 goto err_unregister_notifier; 372 373 ret = xe_i2c_register_adapter(i2c); 374 if (ret) 375 goto err_remove_irq; 376 377 xe_i2c_irq_postinstall(xe); 378 return devm_add_action_or_reset(drm_dev, xe_i2c_remove, i2c); 379 380 err_remove_irq: 381 xe_i2c_remove_irq(i2c); 382 383 err_unregister_notifier: 384 bus_unregister_notifier(&i2c_bus_type, &i2c->bus_notifier); 385 386 return ret; 387 } 388