1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * i2c Support for Atmel's AT91 Two-Wire Interface (TWI) 4 * 5 * Copyright (C) 2011 Weinmann Medical GmbH 6 * Author: Nikolaus Voss <n.voss@weinmann.de> 7 * 8 * Evolved from original work by: 9 * Copyright (C) 2004 Rick Bronson 10 * Converted to 2.6 by Andrew Victor <andrew@sanpeople.com> 11 * 12 * Borrowed heavily from original work by: 13 * Copyright (C) 2000 Philip Edelbrock <phil@stimpy.netroedge.com> 14 */ 15 16 #include <linux/clk.h> 17 #include <linux/err.h> 18 #include <linux/i2c.h> 19 #include <linux/io.h> 20 #include <linux/module.h> 21 #include <linux/of.h> 22 #include <linux/of_device.h> 23 #include <linux/platform_device.h> 24 #include <linux/pm_runtime.h> 25 #include <linux/pinctrl/consumer.h> 26 27 #include "i2c-at91.h" 28 29 unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg) 30 { 31 return readl_relaxed(dev->base + reg); 32 } 33 34 void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val) 35 { 36 writel_relaxed(val, dev->base + reg); 37 } 38 39 void at91_disable_twi_interrupts(struct at91_twi_dev *dev) 40 { 41 at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK); 42 } 43 44 void at91_twi_irq_save(struct at91_twi_dev *dev) 45 { 46 dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & AT91_TWI_INT_MASK; 47 at91_disable_twi_interrupts(dev); 48 } 49 50 void at91_twi_irq_restore(struct at91_twi_dev *dev) 51 { 52 at91_twi_write(dev, AT91_TWI_IER, dev->imr); 53 } 54 55 void at91_init_twi_bus(struct at91_twi_dev *dev) 56 { 57 at91_disable_twi_interrupts(dev); 58 at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST); 59 if (dev->slave_detected) 60 at91_init_twi_bus_slave(dev); 61 else 62 at91_init_twi_bus_master(dev); 63 } 64 65 static struct at91_twi_pdata at91rm9200_config = { 66 .clk_max_div = 5, 67 .clk_offset = 3, 68 .has_unre_flag = true, 69 .has_alt_cmd = false, 70 .has_hold_field = false, 71 }; 72 73 static struct at91_twi_pdata at91sam9261_config = { 74 .clk_max_div = 5, 75 .clk_offset = 4, 76 .has_unre_flag = false, 77 .has_alt_cmd = false, 78 .has_hold_field = false, 79 }; 80 81 static struct at91_twi_pdata at91sam9260_config = { 82 .clk_max_div = 7, 83 .clk_offset = 4, 84 .has_unre_flag = false, 85 .has_alt_cmd = false, 86 .has_hold_field = false, 87 }; 88 89 static struct at91_twi_pdata at91sam9g20_config = { 90 .clk_max_div = 7, 91 .clk_offset = 4, 92 .has_unre_flag = false, 93 .has_alt_cmd = false, 94 .has_hold_field = false, 95 }; 96 97 static struct at91_twi_pdata at91sam9g10_config = { 98 .clk_max_div = 7, 99 .clk_offset = 4, 100 .has_unre_flag = false, 101 .has_alt_cmd = false, 102 .has_hold_field = false, 103 }; 104 105 static const struct platform_device_id at91_twi_devtypes[] = { 106 { 107 .name = "i2c-at91rm9200", 108 .driver_data = (unsigned long) &at91rm9200_config, 109 }, { 110 .name = "i2c-at91sam9261", 111 .driver_data = (unsigned long) &at91sam9261_config, 112 }, { 113 .name = "i2c-at91sam9260", 114 .driver_data = (unsigned long) &at91sam9260_config, 115 }, { 116 .name = "i2c-at91sam9g20", 117 .driver_data = (unsigned long) &at91sam9g20_config, 118 }, { 119 .name = "i2c-at91sam9g10", 120 .driver_data = (unsigned long) &at91sam9g10_config, 121 }, { 122 /* sentinel */ 123 } 124 }; 125 126 #if defined(CONFIG_OF) 127 static struct at91_twi_pdata at91sam9x5_config = { 128 .clk_max_div = 7, 129 .clk_offset = 4, 130 .has_unre_flag = false, 131 .has_alt_cmd = false, 132 .has_hold_field = false, 133 }; 134 135 static struct at91_twi_pdata sama5d4_config = { 136 .clk_max_div = 7, 137 .clk_offset = 4, 138 .has_unre_flag = false, 139 .has_alt_cmd = false, 140 .has_hold_field = true, 141 }; 142 143 static struct at91_twi_pdata sama5d2_config = { 144 .clk_max_div = 7, 145 .clk_offset = 3, 146 .has_unre_flag = true, 147 .has_alt_cmd = true, 148 .has_hold_field = true, 149 }; 150 151 static const struct of_device_id atmel_twi_dt_ids[] = { 152 { 153 .compatible = "atmel,at91rm9200-i2c", 154 .data = &at91rm9200_config, 155 }, { 156 .compatible = "atmel,at91sam9260-i2c", 157 .data = &at91sam9260_config, 158 }, { 159 .compatible = "atmel,at91sam9261-i2c", 160 .data = &at91sam9261_config, 161 }, { 162 .compatible = "atmel,at91sam9g20-i2c", 163 .data = &at91sam9g20_config, 164 }, { 165 .compatible = "atmel,at91sam9g10-i2c", 166 .data = &at91sam9g10_config, 167 }, { 168 .compatible = "atmel,at91sam9x5-i2c", 169 .data = &at91sam9x5_config, 170 }, { 171 .compatible = "atmel,sama5d4-i2c", 172 .data = &sama5d4_config, 173 }, { 174 .compatible = "atmel,sama5d2-i2c", 175 .data = &sama5d2_config, 176 }, { 177 /* sentinel */ 178 } 179 }; 180 MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids); 181 #endif 182 183 static struct at91_twi_pdata *at91_twi_get_driver_data( 184 struct platform_device *pdev) 185 { 186 if (pdev->dev.of_node) { 187 const struct of_device_id *match; 188 match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node); 189 if (!match) 190 return NULL; 191 return (struct at91_twi_pdata *)match->data; 192 } 193 return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data; 194 } 195 196 static int at91_twi_probe(struct platform_device *pdev) 197 { 198 struct at91_twi_dev *dev; 199 struct resource *mem; 200 int rc; 201 u32 phy_addr; 202 203 dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); 204 if (!dev) 205 return -ENOMEM; 206 207 dev->dev = &pdev->dev; 208 209 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 210 if (!mem) 211 return -ENODEV; 212 phy_addr = mem->start; 213 214 dev->pdata = at91_twi_get_driver_data(pdev); 215 if (!dev->pdata) 216 return -ENODEV; 217 218 dev->base = devm_ioremap_resource(&pdev->dev, mem); 219 if (IS_ERR(dev->base)) 220 return PTR_ERR(dev->base); 221 222 dev->irq = platform_get_irq(pdev, 0); 223 if (dev->irq < 0) 224 return dev->irq; 225 226 platform_set_drvdata(pdev, dev); 227 228 dev->clk = devm_clk_get(dev->dev, NULL); 229 if (IS_ERR(dev->clk)) { 230 dev_err(dev->dev, "no clock defined\n"); 231 return -ENODEV; 232 } 233 clk_prepare_enable(dev->clk); 234 235 snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91"); 236 i2c_set_adapdata(&dev->adapter, dev); 237 dev->adapter.owner = THIS_MODULE; 238 dev->adapter.class = I2C_CLASS_DEPRECATED; 239 dev->adapter.dev.parent = dev->dev; 240 dev->adapter.nr = pdev->id; 241 dev->adapter.timeout = AT91_I2C_TIMEOUT; 242 dev->adapter.dev.of_node = pdev->dev.of_node; 243 244 dev->slave_detected = i2c_detect_slave_mode(&pdev->dev); 245 246 if (dev->slave_detected) 247 rc = at91_twi_probe_slave(pdev, phy_addr, dev); 248 else 249 rc = at91_twi_probe_master(pdev, phy_addr, dev); 250 if (rc) 251 return rc; 252 253 at91_init_twi_bus(dev); 254 255 pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT); 256 pm_runtime_use_autosuspend(dev->dev); 257 pm_runtime_set_active(dev->dev); 258 pm_runtime_enable(dev->dev); 259 260 rc = i2c_add_numbered_adapter(&dev->adapter); 261 if (rc) { 262 clk_disable_unprepare(dev->clk); 263 264 pm_runtime_disable(dev->dev); 265 pm_runtime_set_suspended(dev->dev); 266 267 return rc; 268 } 269 270 dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n", 271 at91_twi_read(dev, AT91_TWI_VER)); 272 return 0; 273 } 274 275 static int at91_twi_remove(struct platform_device *pdev) 276 { 277 struct at91_twi_dev *dev = platform_get_drvdata(pdev); 278 279 i2c_del_adapter(&dev->adapter); 280 clk_disable_unprepare(dev->clk); 281 282 pm_runtime_disable(dev->dev); 283 pm_runtime_set_suspended(dev->dev); 284 285 return 0; 286 } 287 288 #ifdef CONFIG_PM 289 290 static int at91_twi_runtime_suspend(struct device *dev) 291 { 292 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); 293 294 clk_disable_unprepare(twi_dev->clk); 295 296 pinctrl_pm_select_sleep_state(dev); 297 298 return 0; 299 } 300 301 static int at91_twi_runtime_resume(struct device *dev) 302 { 303 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); 304 305 pinctrl_pm_select_default_state(dev); 306 307 return clk_prepare_enable(twi_dev->clk); 308 } 309 310 static int at91_twi_suspend_noirq(struct device *dev) 311 { 312 if (!pm_runtime_status_suspended(dev)) 313 at91_twi_runtime_suspend(dev); 314 315 return 0; 316 } 317 318 static int at91_twi_resume_noirq(struct device *dev) 319 { 320 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); 321 int ret; 322 323 if (!pm_runtime_status_suspended(dev)) { 324 ret = at91_twi_runtime_resume(dev); 325 if (ret) 326 return ret; 327 } 328 329 pm_runtime_mark_last_busy(dev); 330 pm_request_autosuspend(dev); 331 332 at91_init_twi_bus(twi_dev); 333 334 return 0; 335 } 336 337 static const struct dev_pm_ops at91_twi_pm = { 338 .suspend_noirq = at91_twi_suspend_noirq, 339 .resume_noirq = at91_twi_resume_noirq, 340 .runtime_suspend = at91_twi_runtime_suspend, 341 .runtime_resume = at91_twi_runtime_resume, 342 }; 343 344 #define at91_twi_pm_ops (&at91_twi_pm) 345 #else 346 #define at91_twi_pm_ops NULL 347 #endif 348 349 static struct platform_driver at91_twi_driver = { 350 .probe = at91_twi_probe, 351 .remove = at91_twi_remove, 352 .id_table = at91_twi_devtypes, 353 .driver = { 354 .name = "at91_i2c", 355 .of_match_table = of_match_ptr(atmel_twi_dt_ids), 356 .pm = at91_twi_pm_ops, 357 }, 358 }; 359 360 static int __init at91_twi_init(void) 361 { 362 return platform_driver_register(&at91_twi_driver); 363 } 364 365 static void __exit at91_twi_exit(void) 366 { 367 platform_driver_unregister(&at91_twi_driver); 368 } 369 370 subsys_initcall(at91_twi_init); 371 module_exit(at91_twi_exit); 372 373 MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>"); 374 MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91"); 375 MODULE_LICENSE("GPL"); 376 MODULE_ALIAS("platform:at91_i2c"); 377