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/platform_device.h> 23 #include <linux/pm_runtime.h> 24 #include <linux/pinctrl/consumer.h> 25 26 #include "i2c-at91.h" 27 28 unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg) 29 { 30 return readl_relaxed(dev->base + reg); 31 } 32 33 void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val) 34 { 35 writel_relaxed(val, dev->base + reg); 36 } 37 38 void at91_disable_twi_interrupts(struct at91_twi_dev *dev) 39 { 40 at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK); 41 } 42 43 void at91_twi_irq_save(struct at91_twi_dev *dev) 44 { 45 dev->imr = at91_twi_read(dev, AT91_TWI_IMR) & AT91_TWI_INT_MASK; 46 at91_disable_twi_interrupts(dev); 47 } 48 49 void at91_twi_irq_restore(struct at91_twi_dev *dev) 50 { 51 at91_twi_write(dev, AT91_TWI_IER, dev->imr); 52 } 53 54 void at91_init_twi_bus(struct at91_twi_dev *dev) 55 { 56 at91_disable_twi_interrupts(dev); 57 at91_twi_write(dev, AT91_TWI_CR, AT91_TWI_SWRST); 58 if (dev->slave_detected) 59 at91_init_twi_bus_slave(dev); 60 else 61 at91_init_twi_bus_master(dev); 62 } 63 64 static struct at91_twi_pdata at91rm9200_config = { 65 .clk_max_div = 5, 66 .clk_offset = 3, 67 .has_unre_flag = true, 68 }; 69 70 static struct at91_twi_pdata at91sam9261_config = { 71 .clk_max_div = 5, 72 .clk_offset = 4, 73 }; 74 75 static struct at91_twi_pdata at91sam9260_config = { 76 .clk_max_div = 7, 77 .clk_offset = 4, 78 }; 79 80 static struct at91_twi_pdata at91sam9g20_config = { 81 .clk_max_div = 7, 82 .clk_offset = 4, 83 }; 84 85 static struct at91_twi_pdata at91sam9g10_config = { 86 .clk_max_div = 7, 87 .clk_offset = 4, 88 }; 89 90 static const struct platform_device_id at91_twi_devtypes[] = { 91 { 92 .name = "i2c-at91rm9200", 93 .driver_data = (unsigned long) &at91rm9200_config, 94 }, { 95 .name = "i2c-at91sam9261", 96 .driver_data = (unsigned long) &at91sam9261_config, 97 }, { 98 .name = "i2c-at91sam9260", 99 .driver_data = (unsigned long) &at91sam9260_config, 100 }, { 101 .name = "i2c-at91sam9g20", 102 .driver_data = (unsigned long) &at91sam9g20_config, 103 }, { 104 .name = "i2c-at91sam9g10", 105 .driver_data = (unsigned long) &at91sam9g10_config, 106 }, { 107 /* sentinel */ 108 } 109 }; 110 111 #if defined(CONFIG_OF) 112 static struct at91_twi_pdata at91sam9x5_config = { 113 .clk_max_div = 7, 114 .clk_offset = 4, 115 }; 116 117 static struct at91_twi_pdata sama5d4_config = { 118 .clk_max_div = 7, 119 .clk_offset = 4, 120 .has_hold_field = true, 121 .has_dig_filtr = true, 122 }; 123 124 static struct at91_twi_pdata sama5d2_config = { 125 .clk_max_div = 7, 126 .clk_offset = 3, 127 .has_unre_flag = true, 128 .has_alt_cmd = true, 129 .has_hold_field = true, 130 .has_dig_filtr = true, 131 .has_adv_dig_filtr = true, 132 .has_ana_filtr = true, 133 .has_clear_cmd = false, /* due to errata, CLEAR cmd is not working */ 134 }; 135 136 static struct at91_twi_pdata sam9x60_config = { 137 .clk_max_div = 7, 138 .clk_offset = 3, 139 .has_unre_flag = true, 140 .has_alt_cmd = true, 141 .has_hold_field = true, 142 .has_dig_filtr = true, 143 .has_adv_dig_filtr = true, 144 .has_ana_filtr = true, 145 .has_clear_cmd = true, 146 }; 147 148 static const struct of_device_id atmel_twi_dt_ids[] = { 149 { 150 .compatible = "atmel,at91rm9200-i2c", 151 .data = &at91rm9200_config, 152 }, { 153 .compatible = "atmel,at91sam9260-i2c", 154 .data = &at91sam9260_config, 155 }, { 156 .compatible = "atmel,at91sam9261-i2c", 157 .data = &at91sam9261_config, 158 }, { 159 .compatible = "atmel,at91sam9g20-i2c", 160 .data = &at91sam9g20_config, 161 }, { 162 .compatible = "atmel,at91sam9g10-i2c", 163 .data = &at91sam9g10_config, 164 }, { 165 .compatible = "atmel,at91sam9x5-i2c", 166 .data = &at91sam9x5_config, 167 }, { 168 .compatible = "atmel,sama5d4-i2c", 169 .data = &sama5d4_config, 170 }, { 171 .compatible = "atmel,sama5d2-i2c", 172 .data = &sama5d2_config, 173 }, { 174 .compatible = "microchip,sam9x60-i2c", 175 .data = &sam9x60_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 dev->base = devm_platform_get_and_ioremap_resource(pdev, 0, &mem); 210 if (IS_ERR(dev->base)) 211 return PTR_ERR(dev->base); 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->irq = platform_get_irq(pdev, 0); 219 if (dev->irq < 0) 220 return dev->irq; 221 222 platform_set_drvdata(pdev, dev); 223 224 dev->clk = devm_clk_get(dev->dev, NULL); 225 if (IS_ERR(dev->clk)) 226 return dev_err_probe(dev->dev, PTR_ERR(dev->clk), "no clock defined\n"); 227 228 clk_prepare_enable(dev->clk); 229 230 snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91"); 231 i2c_set_adapdata(&dev->adapter, dev); 232 dev->adapter.owner = THIS_MODULE; 233 dev->adapter.class = I2C_CLASS_DEPRECATED; 234 dev->adapter.dev.parent = dev->dev; 235 dev->adapter.nr = pdev->id; 236 dev->adapter.timeout = AT91_I2C_TIMEOUT; 237 dev->adapter.dev.of_node = pdev->dev.of_node; 238 239 dev->slave_detected = i2c_detect_slave_mode(&pdev->dev); 240 241 if (dev->slave_detected) 242 rc = at91_twi_probe_slave(pdev, phy_addr, dev); 243 else 244 rc = at91_twi_probe_master(pdev, phy_addr, dev); 245 if (rc) 246 return rc; 247 248 at91_init_twi_bus(dev); 249 250 pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT); 251 pm_runtime_use_autosuspend(dev->dev); 252 pm_runtime_set_active(dev->dev); 253 pm_runtime_enable(dev->dev); 254 255 rc = i2c_add_numbered_adapter(&dev->adapter); 256 if (rc) { 257 clk_disable_unprepare(dev->clk); 258 259 pm_runtime_disable(dev->dev); 260 pm_runtime_set_suspended(dev->dev); 261 262 return rc; 263 } 264 265 dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n", 266 at91_twi_read(dev, AT91_TWI_VER)); 267 return 0; 268 } 269 270 static void at91_twi_remove(struct platform_device *pdev) 271 { 272 struct at91_twi_dev *dev = platform_get_drvdata(pdev); 273 274 i2c_del_adapter(&dev->adapter); 275 clk_disable_unprepare(dev->clk); 276 277 pm_runtime_disable(dev->dev); 278 pm_runtime_set_suspended(dev->dev); 279 } 280 281 static int __maybe_unused at91_twi_runtime_suspend(struct device *dev) 282 { 283 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); 284 285 clk_disable_unprepare(twi_dev->clk); 286 287 pinctrl_pm_select_sleep_state(dev); 288 289 return 0; 290 } 291 292 static int __maybe_unused at91_twi_runtime_resume(struct device *dev) 293 { 294 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); 295 296 pinctrl_pm_select_default_state(dev); 297 298 return clk_prepare_enable(twi_dev->clk); 299 } 300 301 static int __maybe_unused at91_twi_suspend_noirq(struct device *dev) 302 { 303 if (!pm_runtime_status_suspended(dev)) 304 at91_twi_runtime_suspend(dev); 305 306 return 0; 307 } 308 309 static int __maybe_unused at91_twi_resume_noirq(struct device *dev) 310 { 311 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev); 312 int ret; 313 314 if (!pm_runtime_status_suspended(dev)) { 315 ret = at91_twi_runtime_resume(dev); 316 if (ret) 317 return ret; 318 } 319 320 pm_runtime_mark_last_busy(dev); 321 pm_request_autosuspend(dev); 322 323 at91_init_twi_bus(twi_dev); 324 325 return 0; 326 } 327 328 static const struct dev_pm_ops __maybe_unused at91_twi_pm = { 329 .suspend_noirq = at91_twi_suspend_noirq, 330 .resume_noirq = at91_twi_resume_noirq, 331 .runtime_suspend = at91_twi_runtime_suspend, 332 .runtime_resume = at91_twi_runtime_resume, 333 }; 334 335 static struct platform_driver at91_twi_driver = { 336 .probe = at91_twi_probe, 337 .remove_new = at91_twi_remove, 338 .id_table = at91_twi_devtypes, 339 .driver = { 340 .name = "at91_i2c", 341 .of_match_table = of_match_ptr(atmel_twi_dt_ids), 342 .pm = pm_ptr(&at91_twi_pm), 343 }, 344 }; 345 346 static int __init at91_twi_init(void) 347 { 348 return platform_driver_register(&at91_twi_driver); 349 } 350 351 static void __exit at91_twi_exit(void) 352 { 353 platform_driver_unregister(&at91_twi_driver); 354 } 355 356 subsys_initcall(at91_twi_init); 357 module_exit(at91_twi_exit); 358 359 MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>"); 360 MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91"); 361 MODULE_LICENSE("GPL"); 362 MODULE_ALIAS("platform:at91_i2c"); 363