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 int ret; 97 u32 id; 98 99 id = (pci_domain_nr(pci->bus) << 16) | pci_dev_id(pci); 100 101 /* 102 * Not using platform_device_register_full() here because we don't have 103 * a handle to the platform_device before it returns. xe_i2c_notifier() 104 * uses that handle, but it may be called before 105 * platform_device_register_full() is done. 106 */ 107 pdev = platform_device_alloc(adapter_name, id); 108 if (!pdev) 109 return -ENOMEM; 110 111 ret = device_create_managed_software_node(&pdev->dev, 112 xe_i2c_adapter_properties, 113 NULL); 114 if (ret) 115 goto err_pdev_put; 116 117 if (i2c->adapter_irq) { 118 struct resource res; 119 120 res = DEFINE_RES_IRQ_NAMED(i2c->adapter_irq, "xe_i2c"); 121 122 ret = platform_device_add_resources(pdev, &res, 1); 123 if (ret) 124 goto err_pdev_put; 125 } 126 127 pdev->dev.parent = i2c->drm_dev; 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); 138 139 return ret; 140 } 141 142 static void xe_i2c_unregister_adapter(struct xe_i2c *i2c) 143 { 144 platform_device_unregister(i2c->pdev); 145 } 146 147 /** 148 * xe_i2c_present - I2C controller is present and functional 149 * @xe: xe device instance 150 * 151 * Check whether the I2C controller is present and functioning with valid 152 * endpoint cookie. 153 * 154 * Return: %true if present, %false otherwise. 155 */ 156 bool xe_i2c_present(struct xe_device *xe) 157 { 158 return xe->i2c && xe->i2c->ep.cookie == XE_I2C_EP_COOKIE_DEVICE; 159 } 160 161 static bool xe_i2c_irq_present(struct xe_device *xe) 162 { 163 return xe->i2c && xe->i2c->adapter_irq; 164 } 165 166 /** 167 * xe_i2c_irq_handler: Handler for I2C interrupts 168 * @xe: xe device instance 169 * @master_ctl: interrupt register 170 * 171 * Forward interrupts generated by the I2C host adapter to the I2C host adapter 172 * driver. 173 */ 174 void xe_i2c_irq_handler(struct xe_device *xe, u32 master_ctl) 175 { 176 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 177 178 if (!(master_ctl & I2C_IRQ) || !xe_i2c_irq_present(xe)) 179 return; 180 181 /* Forward interrupt to I2C adapter */ 182 generic_handle_irq_safe(xe->i2c->adapter_irq); 183 184 /* Deassert after I2C adapter clears the interrupt */ 185 xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, 0, PCI_COMMAND_INTX_DISABLE); 186 /* Reassert to allow subsequent interrupt generation */ 187 xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, PCI_COMMAND_INTX_DISABLE, 0); 188 } 189 190 void xe_i2c_irq_reset(struct xe_device *xe) 191 { 192 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 193 194 if (!xe_i2c_irq_present(xe)) 195 return; 196 197 xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, 0, PCI_COMMAND_INTX_DISABLE); 198 xe_mmio_rmw32(mmio, I2C_BRIDGE_PCICFGCTL, ACPI_INTR_EN, 0); 199 } 200 201 void xe_i2c_irq_postinstall(struct xe_device *xe) 202 { 203 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 204 205 if (!xe_i2c_irq_present(xe)) 206 return; 207 208 xe_mmio_rmw32(mmio, I2C_BRIDGE_PCICFGCTL, 0, ACPI_INTR_EN); 209 xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, PCI_COMMAND_INTX_DISABLE, 0); 210 } 211 212 static int xe_i2c_irq_map(struct irq_domain *h, unsigned int virq, 213 irq_hw_number_t hw_irq_num) 214 { 215 irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); 216 return 0; 217 } 218 219 static const struct irq_domain_ops xe_i2c_irq_ops = { 220 .map = xe_i2c_irq_map, 221 }; 222 223 static int xe_i2c_create_irq(struct xe_device *xe) 224 { 225 struct xe_i2c *i2c = xe->i2c; 226 struct irq_domain *domain; 227 228 if (!(i2c->ep.capabilities & XE_I2C_EP_CAP_IRQ) || 229 xe_survivability_mode_is_boot_enabled(xe)) 230 return 0; 231 232 domain = irq_domain_create_linear(dev_fwnode(i2c->drm_dev), 1, &xe_i2c_irq_ops, NULL); 233 if (!domain) 234 return -ENOMEM; 235 236 i2c->adapter_irq = irq_create_mapping(domain, 0); 237 i2c->irqdomain = domain; 238 239 return 0; 240 } 241 242 static void xe_i2c_remove_irq(struct xe_i2c *i2c) 243 { 244 if (!i2c->irqdomain) 245 return; 246 247 irq_dispose_mapping(i2c->adapter_irq); 248 irq_domain_remove(i2c->irqdomain); 249 } 250 251 static int xe_i2c_read(void *context, unsigned int reg, unsigned int *val) 252 { 253 struct xe_i2c *i2c = context; 254 255 *val = xe_mmio_read32(i2c->mmio, XE_REG(reg + I2C_MEM_SPACE_OFFSET)); 256 257 return 0; 258 } 259 260 static int xe_i2c_write(void *context, unsigned int reg, unsigned int val) 261 { 262 struct xe_i2c *i2c = context; 263 264 xe_mmio_write32(i2c->mmio, XE_REG(reg + I2C_MEM_SPACE_OFFSET), val); 265 266 return 0; 267 } 268 269 static const struct regmap_config i2c_regmap_config = { 270 .reg_bits = 32, 271 .val_bits = 32, 272 .reg_read = xe_i2c_read, 273 .reg_write = xe_i2c_write, 274 .fast_io = true, 275 }; 276 277 void xe_i2c_pm_suspend(struct xe_device *xe) 278 { 279 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 280 281 if (!xe_i2c_present(xe)) 282 return; 283 284 xe_mmio_rmw32(mmio, I2C_CONFIG_PMCSR, PCI_PM_CTRL_STATE_MASK, (__force u32)PCI_D3hot); 285 drm_dbg(&xe->drm, "pmcsr: 0x%08x\n", xe_mmio_read32(mmio, I2C_CONFIG_PMCSR)); 286 } 287 288 void xe_i2c_pm_resume(struct xe_device *xe, bool d3cold) 289 { 290 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 291 292 if (!xe_i2c_present(xe)) 293 return; 294 295 if (d3cold) 296 xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, 0, PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER); 297 298 xe_mmio_rmw32(mmio, I2C_CONFIG_PMCSR, PCI_PM_CTRL_STATE_MASK, (__force u32)PCI_D0); 299 drm_dbg(&xe->drm, "pmcsr: 0x%08x\n", xe_mmio_read32(mmio, I2C_CONFIG_PMCSR)); 300 } 301 302 static void xe_i2c_remove(void *data) 303 { 304 struct xe_i2c *i2c = data; 305 unsigned int i; 306 307 for (i = 0; i < XE_I2C_MAX_CLIENTS; i++) 308 i2c_unregister_device(i2c->client[i]); 309 310 bus_unregister_notifier(&i2c_bus_type, &i2c->bus_notifier); 311 xe_i2c_unregister_adapter(i2c); 312 xe_i2c_remove_irq(i2c); 313 } 314 315 /** 316 * xe_i2c_probe: Probe the I2C host adapter and the I2C clients attached to it 317 * @xe: xe device instance 318 * 319 * Register all the I2C devices described in the I2C Endpoint data structure. 320 * 321 * Return: 0 on success, error code on failure 322 */ 323 int xe_i2c_probe(struct xe_device *xe) 324 { 325 struct device *drm_dev = xe->drm.dev; 326 struct xe_i2c_endpoint ep; 327 struct regmap *regmap; 328 struct xe_i2c *i2c; 329 int ret; 330 331 if (!xe->info.has_i2c) 332 return 0; 333 334 xe_i2c_read_endpoint(xe_root_tile_mmio(xe), &ep); 335 if (ep.cookie != XE_I2C_EP_COOKIE_DEVICE) 336 return 0; 337 338 i2c = devm_kzalloc(drm_dev, sizeof(*i2c), GFP_KERNEL); 339 if (!i2c) 340 return -ENOMEM; 341 342 INIT_WORK(&i2c->work, xe_i2c_client_work); 343 i2c->mmio = xe_root_tile_mmio(xe); 344 i2c->drm_dev = drm_dev; 345 i2c->ep = ep; 346 xe->i2c = i2c; 347 348 /* PCI PM isn't aware of this device, bring it up and match it with SGUnit state. */ 349 xe_i2c_pm_resume(xe, true); 350 351 regmap = devm_regmap_init(drm_dev, NULL, i2c, &i2c_regmap_config); 352 if (IS_ERR(regmap)) 353 return PTR_ERR(regmap); 354 355 i2c->bus_notifier.notifier_call = xe_i2c_notifier; 356 ret = bus_register_notifier(&i2c_bus_type, &i2c->bus_notifier); 357 if (ret) 358 return ret; 359 360 ret = xe_i2c_create_irq(xe); 361 if (ret) 362 goto err_unregister_notifier; 363 364 ret = xe_i2c_register_adapter(i2c); 365 if (ret) 366 goto err_remove_irq; 367 368 xe_i2c_irq_postinstall(xe); 369 return devm_add_action_or_reset(drm_dev, xe_i2c_remove, i2c); 370 371 err_remove_irq: 372 xe_i2c_remove_irq(i2c); 373 374 err_unregister_notifier: 375 bus_unregister_notifier(&i2c_bus_type, &i2c->bus_notifier); 376 377 return ret; 378 } 379