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_irq_handler: Handler for I2C interrupts 151 * @xe: xe device instance 152 * @master_ctl: interrupt register 153 * 154 * Forward interrupts generated by the I2C host adapter to the I2C host adapter 155 * driver. 156 */ 157 void xe_i2c_irq_handler(struct xe_device *xe, u32 master_ctl) 158 { 159 if (!xe->i2c || !xe->i2c->adapter_irq) 160 return; 161 162 if (master_ctl & I2C_IRQ) 163 generic_handle_irq_safe(xe->i2c->adapter_irq); 164 } 165 166 static int xe_i2c_irq_map(struct irq_domain *h, unsigned int virq, 167 irq_hw_number_t hw_irq_num) 168 { 169 irq_set_chip_and_handler(virq, &dummy_irq_chip, handle_simple_irq); 170 return 0; 171 } 172 173 static const struct irq_domain_ops xe_i2c_irq_ops = { 174 .map = xe_i2c_irq_map, 175 }; 176 177 static int xe_i2c_create_irq(struct xe_i2c *i2c) 178 { 179 struct irq_domain *domain; 180 181 if (!(i2c->ep.capabilities & XE_I2C_EP_CAP_IRQ)) 182 return 0; 183 184 domain = irq_domain_create_linear(dev_fwnode(i2c->drm_dev), 1, &xe_i2c_irq_ops, NULL); 185 if (!domain) 186 return -ENOMEM; 187 188 i2c->adapter_irq = irq_create_mapping(domain, 0); 189 i2c->irqdomain = domain; 190 191 return 0; 192 } 193 194 static void xe_i2c_remove_irq(struct xe_i2c *i2c) 195 { 196 if (!i2c->irqdomain) 197 return; 198 199 irq_dispose_mapping(i2c->adapter_irq); 200 irq_domain_remove(i2c->irqdomain); 201 } 202 203 static int xe_i2c_read(void *context, unsigned int reg, unsigned int *val) 204 { 205 struct xe_i2c *i2c = context; 206 207 *val = xe_mmio_read32(i2c->mmio, XE_REG(reg + I2C_MEM_SPACE_OFFSET)); 208 209 return 0; 210 } 211 212 static int xe_i2c_write(void *context, unsigned int reg, unsigned int val) 213 { 214 struct xe_i2c *i2c = context; 215 216 xe_mmio_write32(i2c->mmio, XE_REG(reg + I2C_MEM_SPACE_OFFSET), val); 217 218 return 0; 219 } 220 221 static const struct regmap_config i2c_regmap_config = { 222 .reg_bits = 32, 223 .val_bits = 32, 224 .reg_read = xe_i2c_read, 225 .reg_write = xe_i2c_write, 226 .fast_io = true, 227 }; 228 229 void xe_i2c_pm_suspend(struct xe_device *xe) 230 { 231 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 232 233 if (!xe->i2c || xe->i2c->ep.cookie != XE_I2C_EP_COOKIE_DEVICE) 234 return; 235 236 xe_mmio_rmw32(mmio, I2C_CONFIG_PMCSR, PCI_PM_CTRL_STATE_MASK, (__force u32)PCI_D3hot); 237 drm_dbg(&xe->drm, "pmcsr: 0x%08x\n", xe_mmio_read32(mmio, I2C_CONFIG_PMCSR)); 238 } 239 240 void xe_i2c_pm_resume(struct xe_device *xe, bool d3cold) 241 { 242 struct xe_mmio *mmio = xe_root_tile_mmio(xe); 243 244 if (!xe->i2c || xe->i2c->ep.cookie != XE_I2C_EP_COOKIE_DEVICE) 245 return; 246 247 if (d3cold) 248 xe_mmio_rmw32(mmio, I2C_CONFIG_CMD, 0, PCI_COMMAND_MEMORY); 249 250 xe_mmio_rmw32(mmio, I2C_CONFIG_PMCSR, PCI_PM_CTRL_STATE_MASK, (__force u32)PCI_D0); 251 drm_dbg(&xe->drm, "pmcsr: 0x%08x\n", xe_mmio_read32(mmio, I2C_CONFIG_PMCSR)); 252 } 253 254 static void xe_i2c_remove(void *data) 255 { 256 struct xe_i2c *i2c = data; 257 unsigned int i; 258 259 for (i = 0; i < XE_I2C_MAX_CLIENTS; i++) 260 i2c_unregister_device(i2c->client[i]); 261 262 bus_unregister_notifier(&i2c_bus_type, &i2c->bus_notifier); 263 xe_i2c_unregister_adapter(i2c); 264 xe_i2c_remove_irq(i2c); 265 } 266 267 /** 268 * xe_i2c_probe: Probe the I2C host adapter and the I2C clients attached to it 269 * @xe: xe device instance 270 * 271 * Register all the I2C devices described in the I2C Endpoint data structure. 272 * 273 * Return: 0 on success, error code on failure 274 */ 275 int xe_i2c_probe(struct xe_device *xe) 276 { 277 struct device *drm_dev = xe->drm.dev; 278 struct xe_i2c_endpoint ep; 279 struct regmap *regmap; 280 struct xe_i2c *i2c; 281 int ret; 282 283 if (xe->info.platform != XE_BATTLEMAGE) 284 return 0; 285 286 if (IS_SRIOV_VF(xe)) 287 return 0; 288 289 xe_i2c_read_endpoint(xe_root_tile_mmio(xe), &ep); 290 if (ep.cookie != XE_I2C_EP_COOKIE_DEVICE) 291 return 0; 292 293 i2c = devm_kzalloc(drm_dev, sizeof(*i2c), GFP_KERNEL); 294 if (!i2c) 295 return -ENOMEM; 296 297 INIT_WORK(&i2c->work, xe_i2c_client_work); 298 i2c->mmio = xe_root_tile_mmio(xe); 299 i2c->drm_dev = drm_dev; 300 i2c->ep = ep; 301 xe->i2c = i2c; 302 303 /* PCI PM isn't aware of this device, bring it up and match it with SGUnit state. */ 304 xe_i2c_pm_resume(xe, true); 305 306 regmap = devm_regmap_init(drm_dev, NULL, i2c, &i2c_regmap_config); 307 if (IS_ERR(regmap)) 308 return PTR_ERR(regmap); 309 310 i2c->bus_notifier.notifier_call = xe_i2c_notifier; 311 ret = bus_register_notifier(&i2c_bus_type, &i2c->bus_notifier); 312 if (ret) 313 return ret; 314 315 ret = xe_i2c_create_irq(i2c); 316 if (ret) 317 goto err_unregister_notifier; 318 319 ret = xe_i2c_register_adapter(i2c); 320 if (ret) 321 goto err_remove_irq; 322 323 return devm_add_action_or_reset(drm_dev, xe_i2c_remove, i2c); 324 325 err_remove_irq: 326 xe_i2c_remove_irq(i2c); 327 328 err_unregister_notifier: 329 bus_unregister_notifier(&i2c_bus_type, &i2c->bus_notifier); 330 331 return ret; 332 } 333