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 }; 70 71 static struct at91_twi_pdata at91sam9261_config = { 72 .clk_max_div = 5, 73 .clk_offset = 4, 74 }; 75 76 static struct at91_twi_pdata at91sam9260_config = { 77 .clk_max_div = 7, 78 .clk_offset = 4, 79 }; 80 81 static struct at91_twi_pdata at91sam9g20_config = { 82 .clk_max_div = 7, 83 .clk_offset = 4, 84 }; 85 86 static struct at91_twi_pdata at91sam9g10_config = { 87 .clk_max_div = 7, 88 .clk_offset = 4, 89 }; 90 91 static const struct platform_device_id at91_twi_devtypes[] = { 92 { 93 .name = "i2c-at91rm9200", 94 .driver_data = (unsigned long) &at91rm9200_config, 95 }, { 96 .name = "i2c-at91sam9261", 97 .driver_data = (unsigned long) &at91sam9261_config, 98 }, { 99 .name = "i2c-at91sam9260", 100 .driver_data = (unsigned long) &at91sam9260_config, 101 }, { 102 .name = "i2c-at91sam9g20", 103 .driver_data = (unsigned long) &at91sam9g20_config, 104 }, { 105 .name = "i2c-at91sam9g10", 106 .driver_data = (unsigned long) &at91sam9g10_config, 107 }, { 108 /* sentinel */ 109 } 110 }; 111 112 #if defined(CONFIG_OF) 113 static struct at91_twi_pdata at91sam9x5_config = { 114 .clk_max_div = 7, 115 .clk_offset = 4, 116 }; 117 118 static struct at91_twi_pdata sama5d4_config = { 119 .clk_max_div = 7, 120 .clk_offset = 4, 121 .has_hold_field = true, 122 .has_dig_filtr = true, 123 }; 124 125 static struct at91_twi_pdata sama5d2_config = { 126 .clk_max_div = 7, 127 .clk_offset = 3, 128 .has_unre_flag = true, 129 .has_alt_cmd = true, 130 .has_hold_field = true, 131 .has_dig_filtr = true, 132 .has_adv_dig_filtr = true, 133 .has_ana_filtr = true, 134 .has_clear_cmd = false, /* due to errata, CLEAR cmd is not working */ 135 }; 136 137 static struct at91_twi_pdata sam9x60_config = { 138 .clk_max_div = 7, 139 .clk_offset = 3, 140 .has_unre_flag = true, 141 .has_alt_cmd = true, 142 .has_hold_field = true, 143 .has_dig_filtr = true, 144 .has_adv_dig_filtr = true, 145 .has_ana_filtr = true, 146 .has_clear_cmd = true, 147 }; 148 149 static const struct of_device_id atmel_twi_dt_ids[] = { 150 { 151 .compatible = "atmel,at91rm9200-i2c", 152 .data = &at91rm9200_config, 153 }, { 154 .compatible = "atmel,at91sam9260-i2c", 155 .data = &at91sam9260_config, 156 }, { 157 .compatible = "atmel,at91sam9261-i2c", 158 .data = &at91sam9261_config, 159 }, { 160 .compatible = "atmel,at91sam9g20-i2c", 161 .data = &at91sam9g20_config, 162 }, { 163 .compatible = "atmel,at91sam9g10-i2c", 164 .data = &at91sam9g10_config, 165 }, { 166 .compatible = "atmel,at91sam9x5-i2c", 167 .data = &at91sam9x5_config, 168 }, { 169 .compatible = "atmel,sama5d4-i2c", 170 .data = &sama5d4_config, 171 }, { 172 .compatible = "atmel,sama5d2-i2c", 173 .data = &sama5d2_config, 174 }, { 175 .compatible = "microchip,sam9x60-i2c", 176 .data = &sam9x60_config, 177 }, { 178 /* sentinel */ 179 } 180 }; 181 MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids); 182 #endif 183 184 static struct at91_twi_pdata *at91_twi_get_driver_data( 185 struct platform_device *pdev) 186 { 187 if (pdev->dev.of_node) { 188 const struct of_device_id *match; 189 match = of_match_node(atmel_twi_dt_ids, pdev->dev.of_node); 190 if (!match) 191 return NULL; 192 return (struct at91_twi_pdata *)match->data; 193 } 194 return (struct at91_twi_pdata *) platform_get_device_id(pdev)->driver_data; 195 } 196 197 static int at91_twi_probe(struct platform_device *pdev) 198 { 199 struct at91_twi_dev *dev; 200 struct resource *mem; 201 int rc; 202 u32 phy_addr; 203 204 dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL); 205 if (!dev) 206 return -ENOMEM; 207 208 dev->dev = &pdev->dev; 209 210 mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); 211 if (!mem) 212 return -ENODEV; 213 phy_addr = mem->start; 214 215 dev->pdata = at91_twi_get_driver_data(pdev); 216 if (!dev->pdata) 217 return -ENODEV; 218 219 dev->base = devm_ioremap_resource(&pdev->dev, mem); 220 if (IS_ERR(dev->base)) 221 return PTR_ERR(dev->base); 222 223 dev->irq = platform_get_irq(pdev, 0); 224 if (dev->irq < 0) 225 return dev->irq; 226 227 platform_set_drvdata(pdev, dev); 228 229 dev->clk = devm_clk_get(dev->dev, NULL); 230 if (IS_ERR(dev->clk)) { 231 dev_err(dev->dev, "no clock defined\n"); 232 return -ENODEV; 233 } 234 clk_prepare_enable(dev->clk); 235 236 snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91"); 237 i2c_set_adapdata(&dev->adapter, dev); 238 dev->adapter.owner = THIS_MODULE; 239 dev->adapter.class = I2C_CLASS_DEPRECATED; 240 dev->adapter.dev.parent = dev->dev; 241 dev->adapter.nr = pdev->id; 242 dev->adapter.timeout = AT91_I2C_TIMEOUT; 243 dev->adapter.dev.of_node = pdev->dev.of_node; 244 245 dev->slave_detected = i2c_detect_slave_mode(&pdev->dev); 246 247 if (dev->slave_detected) 248 rc = at91_twi_probe_slave(pdev, phy_addr, dev); 249 else 250 rc = at91_twi_probe_master(pdev, phy_addr, dev); 251 if (rc) 252 return rc; 253 254 at91_init_twi_bus(dev); 255 256 pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT); 257 pm_runtime_use_autosuspend(dev->dev); 258 pm_runtime_set_active(dev->dev); 259 pm_runtime_enable(dev->dev); 260 261 rc = i2c_add_numbered_adapter(&dev->adapter); 262 if (rc) { 263 clk_disable_unprepare(dev->clk); 264 265 pm_runtime_disable(dev->dev); 266 pm_runtime_set_suspended(dev->dev); 267 268 return rc; 269 } 270 271 dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n", 272 at91_twi_read(dev, AT91_TWI_VER)); 273 return 0; 274 } 275 276 static int at91_twi_remove(struct platform_device *pdev) 277 { 278 struct at91_twi_dev *dev = platform_get_drvdata(pdev); 279 280 i2c_del_adapter(&dev->adapter); 281 clk_disable_unprepare(dev->clk); 282 283 pm_runtime_disable(dev->dev); 284 pm_runtime_set_suspended(dev->dev); 285 286 return 0; 287 } 288 289 static int __maybe_unused at91_twi_runtime_suspend(struct device *dev) 290 { 291 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); 292 293 clk_disable_unprepare(twi_dev->clk); 294 295 pinctrl_pm_select_sleep_state(dev); 296 297 return 0; 298 } 299 300 static int __maybe_unused at91_twi_runtime_resume(struct device *dev) 301 { 302 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); 303 304 pinctrl_pm_select_default_state(dev); 305 306 return clk_prepare_enable(twi_dev->clk); 307 } 308 309 static int __maybe_unused at91_twi_suspend_noirq(struct device *dev) 310 { 311 if (!pm_runtime_status_suspended(dev)) 312 at91_twi_runtime_suspend(dev); 313 314 return 0; 315 } 316 317 static int __maybe_unused at91_twi_resume_noirq(struct device *dev) 318 { 319 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); 320 int ret; 321 322 if (!pm_runtime_status_suspended(dev)) { 323 ret = at91_twi_runtime_resume(dev); 324 if (ret) 325 return ret; 326 } 327 328 pm_runtime_mark_last_busy(dev); 329 pm_request_autosuspend(dev); 330 331 at91_init_twi_bus(twi_dev); 332 333 return 0; 334 } 335 336 static const struct dev_pm_ops __maybe_unused at91_twi_pm = { 337 .suspend_noirq = at91_twi_suspend_noirq, 338 .resume_noirq = at91_twi_resume_noirq, 339 .runtime_suspend = at91_twi_runtime_suspend, 340 .runtime_resume = at91_twi_runtime_resume, 341 }; 342 343 static struct platform_driver at91_twi_driver = { 344 .probe = at91_twi_probe, 345 .remove = at91_twi_remove, 346 .id_table = at91_twi_devtypes, 347 .driver = { 348 .name = "at91_i2c", 349 .of_match_table = of_match_ptr(atmel_twi_dt_ids), 350 .pm = pm_ptr(&at91_twi_pm), 351 }, 352 }; 353 354 static int __init at91_twi_init(void) 355 { 356 return platform_driver_register(&at91_twi_driver); 357 } 358 359 static void __exit at91_twi_exit(void) 360 { 361 platform_driver_unregister(&at91_twi_driver); 362 } 363 364 subsys_initcall(at91_twi_init); 365 module_exit(at91_twi_exit); 366 367 MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>"); 368 MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91"); 369 MODULE_LICENSE("GPL"); 370 MODULE_ALIAS("platform:at91_i2c"); 371