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_types.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 99 fwnode = fwnode_create_software_node(xe_i2c_adapter_properties, NULL); 100 if (IS_ERR(fwnode)) 101 return PTR_ERR(fwnode); 102 103 /* 104 * Not using platform_device_register_full() here because we don't have 105 * a handle to the platform_device before it returns. xe_i2c_notifier() 106 * uses that handle, but it may be called before 107 * platform_device_register_full() is done. 108 */ 109 pdev = platform_device_alloc(adapter_name, pci_dev_id(pci)); 110 if (!pdev) { 111 ret = -ENOMEM; 112 goto err_fwnode_remove; 113 } 114 115 if (i2c->adapter_irq) { 116 struct resource res; 117 118 res = DEFINE_RES_IRQ_NAMED(i2c->adapter_irq, "xe_i2c"); 119 120 ret = platform_device_add_resources(pdev, &res, 1); 121 if (ret) 122 goto err_pdev_put; 123 } 124 125 pdev->dev.parent = i2c->drm_dev; 126 pdev->dev.fwnode = fwnode; 127 i2c->adapter_node = fwnode; 128 i2c->pdev = pdev; 129 130 ret = platform_device_add(pdev); 131 if (ret) 132 goto err_pdev_put; 133 134 return 0; 135 136 err_pdev_put: 137 platform_device_put(pdev); 138 err_fwnode_remove: 139 fwnode_remove_software_node(fwnode); 140 141 return ret; 142 } 143 144 static void xe_i2c_unregister_adapter(struct xe_i2c *i2c) 145 { 146 platform_device_unregister(i2c->pdev); 147 fwnode_remove_software_node(i2c->adapter_node); 148 } 149 150 /** 151 * xe_i2c_present - I2C controller is present and functional 152 * @xe: xe device instance 153 * 154 * Check whether the I2C controller is present and functioning with valid 155 * endpoint cookie. 156 * 157 * Return: %true if present, %false otherwise. 158 */ 159 bool xe_i2c_present(struct xe_device *xe) 160 { 161 return xe->i2c && xe->i2c->ep.cookie == XE_I2C_EP_COOKIE_DEVICE; 162 } 163 164 static bool xe_i2c_irq_present(struct xe_device *xe) 165 { 166 return xe->i2c && xe->i2c->adapter_irq; 167 } 168 169 /** 170 * xe_i2c_irq_handler: Handler for I2C interrupts 171 * @xe: xe device instance 172 * @master_ctl: interrupt register 173 * 174 * Forward interrupts generated by the I2C host adapter to the I2C host adapter 175 * driver. 176 */ 177 void xe_i2c_irq_handler(struct xe_device *xe, u32 master_ctl) 178 { 179 if (!xe_i2c_irq_present(xe)) 180 return; 181 182 if (master_ctl & I2C_IRQ) 183 generic_handle_irq_safe(xe->i2c->adapter_irq); 184 } 185 186 void xe_i2c_irq_reset(struct xe_device *xe) 187 { 188 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 189 190 if (!xe_i2c_irq_present(xe)) 191 return; 192 193 xe_mmio_rmw32(mmio, I2C_BRIDGE_PCICFGCTL, ACPI_INTR_EN, 0); 194 } 195 196 void xe_i2c_irq_postinstall(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_BRIDGE_PCICFGCTL, 0, ACPI_INTR_EN); 204 } 205 206 static int xe_i2c_irq_map(struct irq_domain *h, unsigned int virq, 207 irq_hw_number_t hw_irq_num) 208 { 209 irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); 210 return 0; 211 } 212 213 static const struct irq_domain_ops xe_i2c_irq_ops = { 214 .map = xe_i2c_irq_map, 215 }; 216 217 static int xe_i2c_create_irq(struct xe_device *xe) 218 { 219 struct xe_i2c *i2c = xe->i2c; 220 struct irq_domain *domain; 221 222 if (!(i2c->ep.capabilities & XE_I2C_EP_CAP_IRQ) || 223 xe_survivability_mode_is_boot_enabled(xe)) 224 return 0; 225 226 domain = irq_domain_create_linear(dev_fwnode(i2c->drm_dev), 1, &xe_i2c_irq_ops, NULL); 227 if (!domain) 228 return -ENOMEM; 229 230 i2c->adapter_irq = irq_create_mapping(domain, 0); 231 i2c->irqdomain = domain; 232 233 return 0; 234 } 235 236 static void xe_i2c_remove_irq(struct xe_i2c *i2c) 237 { 238 if (!i2c->irqdomain) 239 return; 240 241 irq_dispose_mapping(i2c->adapter_irq); 242 irq_domain_remove(i2c->irqdomain); 243 } 244 245 static int xe_i2c_read(void *context, unsigned int reg, unsigned int *val) 246 { 247 struct xe_i2c *i2c = context; 248 249 *val = xe_mmio_read32(i2c->mmio, XE_REG(reg + I2C_MEM_SPACE_OFFSET)); 250 251 return 0; 252 } 253 254 static int xe_i2c_write(void *context, unsigned int reg, unsigned int val) 255 { 256 struct xe_i2c *i2c = context; 257 258 xe_mmio_write32(i2c->mmio, XE_REG(reg + I2C_MEM_SPACE_OFFSET), val); 259 260 return 0; 261 } 262 263 static const struct regmap_config i2c_regmap_config = { 264 .reg_bits = 32, 265 .val_bits = 32, 266 .reg_read = xe_i2c_read, 267 .reg_write = xe_i2c_write, 268 .fast_io = true, 269 }; 270 271 void xe_i2c_pm_suspend(struct xe_device *xe) 272 { 273 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 274 275 if (!xe_i2c_present(xe)) 276 return; 277 278 xe_mmio_rmw32(mmio, I2C_CONFIG_PMCSR, PCI_PM_CTRL_STATE_MASK, (__force u32)PCI_D3hot); 279 drm_dbg(&xe->drm, "pmcsr: 0x%08x\n", xe_mmio_read32(mmio, I2C_CONFIG_PMCSR)); 280 } 281 282 void xe_i2c_pm_resume(struct xe_device *xe, bool d3cold) 283 { 284 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 285 286 if (!xe_i2c_present(xe)) 287 return; 288 289 if (d3cold) 290 xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, 0, PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER); 291 292 xe_mmio_rmw32(mmio, I2C_CONFIG_PMCSR, PCI_PM_CTRL_STATE_MASK, (__force u32)PCI_D0); 293 drm_dbg(&xe->drm, "pmcsr: 0x%08x\n", xe_mmio_read32(mmio, I2C_CONFIG_PMCSR)); 294 } 295 296 static void xe_i2c_remove(void *data) 297 { 298 struct xe_i2c *i2c = data; 299 unsigned int i; 300 301 for (i = 0; i < XE_I2C_MAX_CLIENTS; i++) 302 i2c_unregister_device(i2c->client[i]); 303 304 bus_unregister_notifier(&i2c_bus_type, &i2c->bus_notifier); 305 xe_i2c_unregister_adapter(i2c); 306 xe_i2c_remove_irq(i2c); 307 } 308 309 /** 310 * xe_i2c_probe: Probe the I2C host adapter and the I2C clients attached to it 311 * @xe: xe device instance 312 * 313 * Register all the I2C devices described in the I2C Endpoint data structure. 314 * 315 * Return: 0 on success, error code on failure 316 */ 317 int xe_i2c_probe(struct xe_device *xe) 318 { 319 struct device *drm_dev = xe->drm.dev; 320 struct xe_i2c_endpoint ep; 321 struct regmap *regmap; 322 struct xe_i2c *i2c; 323 int ret; 324 325 if (!xe->info.has_i2c) 326 return 0; 327 328 if (IS_SRIOV_VF(xe)) 329 return 0; 330 331 xe_i2c_read_endpoint(xe_root_tile_mmio(xe), &ep); 332 if (ep.cookie != XE_I2C_EP_COOKIE_DEVICE) 333 return 0; 334 335 i2c = devm_kzalloc(drm_dev, sizeof(*i2c), GFP_KERNEL); 336 if (!i2c) 337 return -ENOMEM; 338 339 INIT_WORK(&i2c->work, xe_i2c_client_work); 340 i2c->mmio = xe_root_tile_mmio(xe); 341 i2c->drm_dev = drm_dev; 342 i2c->ep = ep; 343 xe->i2c = i2c; 344 345 /* PCI PM isn't aware of this device, bring it up and match it with SGUnit state. */ 346 xe_i2c_pm_resume(xe, true); 347 348 regmap = devm_regmap_init(drm_dev, NULL, i2c, &i2c_regmap_config); 349 if (IS_ERR(regmap)) 350 return PTR_ERR(regmap); 351 352 i2c->bus_notifier.notifier_call = xe_i2c_notifier; 353 ret = bus_register_notifier(&i2c_bus_type, &i2c->bus_notifier); 354 if (ret) 355 return ret; 356 357 ret = xe_i2c_create_irq(xe); 358 if (ret) 359 goto err_unregister_notifier; 360 361 ret = xe_i2c_register_adapter(i2c); 362 if (ret) 363 goto err_remove_irq; 364 365 xe_i2c_irq_postinstall(xe); 366 return devm_add_action_or_reset(drm_dev, xe_i2c_remove, i2c); 367 368 err_remove_irq: 369 xe_i2c_remove_irq(i2c); 370 371 err_unregister_notifier: 372 bus_unregister_notifier(&i2c_bus_type, &i2c->bus_notifier); 373 374 return ret; 375 } 376