359 lines · c
1// SPDX-License-Identifier: GPL-2.02/*3 * i2c Support for Atmel's AT91 Two-Wire Interface (TWI)4 *5 * Copyright (C) 2011 Weinmann Medical GmbH6 * Author: Nikolaus Voss <n.voss@weinmann.de>7 *8 * Evolved from original work by:9 * Copyright (C) 2004 Rick Bronson10 * 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 28unsigned at91_twi_read(struct at91_twi_dev *dev, unsigned reg)29{30 return readl_relaxed(dev->base + reg);31}32 33void at91_twi_write(struct at91_twi_dev *dev, unsigned reg, unsigned val)34{35 writel_relaxed(val, dev->base + reg);36}37 38void at91_disable_twi_interrupts(struct at91_twi_dev *dev)39{40 at91_twi_write(dev, AT91_TWI_IDR, AT91_TWI_INT_MASK);41}42 43void 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 49void at91_twi_irq_restore(struct at91_twi_dev *dev)50{51 at91_twi_write(dev, AT91_TWI_IER, dev->imr);52}53 54void 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 else61 at91_init_twi_bus_master(dev);62}63 64static struct at91_twi_pdata at91rm9200_config = {65 .clk_max_div = 5,66 .clk_offset = 3,67 .has_unre_flag = true,68};69 70static struct at91_twi_pdata at91sam9261_config = {71 .clk_max_div = 5,72 .clk_offset = 4,73};74 75static struct at91_twi_pdata at91sam9260_config = {76 .clk_max_div = 7,77 .clk_offset = 4,78};79 80static struct at91_twi_pdata at91sam9g20_config = {81 .clk_max_div = 7,82 .clk_offset = 4,83};84 85static struct at91_twi_pdata at91sam9g10_config = {86 .clk_max_div = 7,87 .clk_offset = 4,88};89 90static 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)112static struct at91_twi_pdata at91sam9x5_config = {113 .clk_max_div = 7,114 .clk_offset = 4,115};116 117static 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 124static 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 136static 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 148static 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};180MODULE_DEVICE_TABLE(of, atmel_twi_dt_ids);181#endif182 183static 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 196static 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_enabled(dev->dev, NULL);225 if (IS_ERR(dev->clk))226 return dev_err_probe(dev->dev, PTR_ERR(dev->clk),227 "failed to enable clock\n");228 229 snprintf(dev->adapter.name, sizeof(dev->adapter.name), "AT91");230 i2c_set_adapdata(&dev->adapter, dev);231 dev->adapter.owner = THIS_MODULE;232 dev->adapter.class = I2C_CLASS_DEPRECATED;233 dev->adapter.dev.parent = dev->dev;234 dev->adapter.nr = pdev->id;235 dev->adapter.timeout = AT91_I2C_TIMEOUT;236 dev->adapter.dev.of_node = pdev->dev.of_node;237 238 dev->slave_detected = i2c_detect_slave_mode(&pdev->dev);239 240 if (dev->slave_detected)241 rc = at91_twi_probe_slave(pdev, phy_addr, dev);242 else243 rc = at91_twi_probe_master(pdev, phy_addr, dev);244 if (rc)245 return rc;246 247 at91_init_twi_bus(dev);248 249 pm_runtime_set_autosuspend_delay(dev->dev, AUTOSUSPEND_TIMEOUT);250 pm_runtime_use_autosuspend(dev->dev);251 pm_runtime_set_active(dev->dev);252 pm_runtime_enable(dev->dev);253 254 rc = i2c_add_numbered_adapter(&dev->adapter);255 if (rc) {256 pm_runtime_disable(dev->dev);257 pm_runtime_set_suspended(dev->dev);258 259 return rc;260 }261 262 dev_info(dev->dev, "AT91 i2c bus driver (hw version: %#x).\n",263 at91_twi_read(dev, AT91_TWI_VER));264 return 0;265}266 267static void at91_twi_remove(struct platform_device *pdev)268{269 struct at91_twi_dev *dev = platform_get_drvdata(pdev);270 271 i2c_del_adapter(&dev->adapter);272 273 pm_runtime_disable(dev->dev);274 pm_runtime_set_suspended(dev->dev);275}276 277static int __maybe_unused at91_twi_runtime_suspend(struct device *dev)278{279 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);280 281 clk_disable_unprepare(twi_dev->clk);282 283 pinctrl_pm_select_sleep_state(dev);284 285 return 0;286}287 288static int __maybe_unused at91_twi_runtime_resume(struct device *dev)289{290 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);291 292 pinctrl_pm_select_default_state(dev);293 294 return clk_prepare_enable(twi_dev->clk);295}296 297static int __maybe_unused at91_twi_suspend_noirq(struct device *dev)298{299 if (!pm_runtime_status_suspended(dev))300 at91_twi_runtime_suspend(dev);301 302 return 0;303}304 305static int __maybe_unused at91_twi_resume_noirq(struct device *dev)306{307 struct at91_twi_dev *twi_dev = dev_get_drvdata(dev);308 int ret;309 310 if (!pm_runtime_status_suspended(dev)) {311 ret = at91_twi_runtime_resume(dev);312 if (ret)313 return ret;314 }315 316 pm_runtime_mark_last_busy(dev);317 pm_request_autosuspend(dev);318 319 at91_init_twi_bus(twi_dev);320 321 return 0;322}323 324static const struct dev_pm_ops __maybe_unused at91_twi_pm = {325 .suspend_noirq = at91_twi_suspend_noirq,326 .resume_noirq = at91_twi_resume_noirq,327 .runtime_suspend = at91_twi_runtime_suspend,328 .runtime_resume = at91_twi_runtime_resume,329};330 331static struct platform_driver at91_twi_driver = {332 .probe = at91_twi_probe,333 .remove_new = at91_twi_remove,334 .id_table = at91_twi_devtypes,335 .driver = {336 .name = "at91_i2c",337 .of_match_table = of_match_ptr(atmel_twi_dt_ids),338 .pm = pm_ptr(&at91_twi_pm),339 },340};341 342static int __init at91_twi_init(void)343{344 return platform_driver_register(&at91_twi_driver);345}346 347static void __exit at91_twi_exit(void)348{349 platform_driver_unregister(&at91_twi_driver);350}351 352subsys_initcall(at91_twi_init);353module_exit(at91_twi_exit);354 355MODULE_AUTHOR("Nikolaus Voss <n.voss@weinmann.de>");356MODULE_DESCRIPTION("I2C (TWI) driver for Atmel AT91");357MODULE_LICENSE("GPL");358MODULE_ALIAS("platform:at91_i2c");359