linux/drivers/i2c/busses/i2c-at91-core.c
<<
>>
Prefs
   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
  29unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg)
  30{
  31        return readl_relaxed(dev->base + reg);
  32}
  33
  34void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val)
  35{
  36        writel_relaxed(val, dev->base + reg);
  37}
  38
  39void at91_disable_twi_interrupts(struct at91_twi_dev *dev)
  40{
  41        at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK);
  42}
  43
  44void 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
  50void at91_twi_irq_restore(struct at91_twi_dev *dev)
  51{
  52        at91_twi_write(dev, AT91_TWI_IER, dev->imr);
  53}
  54
  55void 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
  65static struct at91_twi_pdata at91rm9200_config = {
  66        .clk_max_div = 5,
  67        .clk_offset = 3,
  68        .has_unre_flag = true,
  69};
  70
  71static struct at91_twi_pdata at91sam9261_config = {
  72        .clk_max_div = 5,
  73        .clk_offset = 4,
  74};
  75
  76static struct at91_twi_pdata at91sam9260_config = {
  77        .clk_max_div = 7,
  78        .clk_offset = 4,
  79};
  80
  81static struct at91_twi_pdata at91sam9g20_config = {
  82        .clk_max_div = 7,
  83        .clk_offset = 4,
  84};
  85
  86static struct at91_twi_pdata at91sam9g10_config = {
  87        .clk_max_div = 7,
  88        .clk_offset = 4,
  89};
  90
  91static 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)
 113static struct at91_twi_pdata at91sam9x5_config = {
 114        .clk_max_div = 7,
 115        .clk_offset = 4,
 116};
 117
 118static 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
 125static 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
 137static 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
 149static 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};
 181MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids);
 182#endif
 183
 184static 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
 197static 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
 276static 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
 289static 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
 300static 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
 309static 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
 317static 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
 336static 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
 343static 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
 354static int __init at91_twi_init(void)
 355{
 356        return platform_driver_register(&at91_twi_driver);
 357}
 358
 359static void __exit at91_twi_exit(void)
 360{
 361        platform_driver_unregister(&at91_twi_driver);
 362}
 363
 364subsys_initcall(at91_twi_init);
 365module_exit(at91_twi_exit);
 366
 367MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>");
 368MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91");
 369MODULE_LICENSE("GPL");
 370MODULE_ALIAS("platform:at91_i2c");
 371