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