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1// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause2/*3 * AMD MP2 platform driver4 *5 * Setup the I2C adapters enumerated in the ACPI namespace.6 * MP2 controllers have 2 separate busses, up to 2 I2C adapters may be listed.7 *8 * Authors: Nehal Bakulchandra Shah <Nehal-bakulchandra.shah@amd.com>9 * Elie Morisse <syniurge@gmail.com>10 */11 12#include <linux/acpi.h>13#include <linux/kernel.h>14#include <linux/module.h>15#include <linux/platform_device.h>16#include <linux/slab.h>17#include <linux/types.h>18 19#include "i2c-amd-mp2.h"20 21#define AMD_MP2_I2C_MAX_RW_LENGTH ((1 << 12) - 1)22#define AMD_I2C_TIMEOUT (msecs_to_jiffies(250))23 24/**25 * struct amd_i2c_dev - MP2 bus/i2c adapter context26 * @common: shared context with the MP2 PCI driver27 * @pdev: platform driver node28 * @adap: i2c adapter29 * @cmd_complete: xfer completion object30 */31struct amd_i2c_dev {32 struct amd_i2c_common common;33 struct platform_device *pdev;34 struct i2c_adapter adap;35 struct completion cmd_complete;36};37 38#define amd_i2c_dev_common(__common) \39 container_of(__common, struct amd_i2c_dev, common)40 41static int i2c_amd_dma_map(struct amd_i2c_common *i2c_common)42{43 struct device *dev_pci = &i2c_common->mp2_dev->pci_dev->dev;44 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);45 enum dma_data_direction dma_direction =46 i2c_common->msg->flags & I2C_M_RD ?47 DMA_FROM_DEVICE : DMA_TO_DEVICE;48 49 i2c_common->dma_buf = i2c_get_dma_safe_msg_buf(i2c_common->msg, 0);50 i2c_common->dma_addr = dma_map_single(dev_pci, i2c_common->dma_buf,51 i2c_common->msg->len,52 dma_direction);53 54 if (unlikely(dma_mapping_error(dev_pci, i2c_common->dma_addr))) {55 dev_err(&i2c_dev->pdev->dev,56 "Error while mapping dma buffer %p\n",57 i2c_common->dma_buf);58 return -EIO;59 }60 61 return 0;62}63 64static void i2c_amd_dma_unmap(struct amd_i2c_common *i2c_common)65{66 struct device *dev_pci = &i2c_common->mp2_dev->pci_dev->dev;67 enum dma_data_direction dma_direction =68 i2c_common->msg->flags & I2C_M_RD ?69 DMA_FROM_DEVICE : DMA_TO_DEVICE;70 71 dma_unmap_single(dev_pci, i2c_common->dma_addr,72 i2c_common->msg->len, dma_direction);73 74 i2c_put_dma_safe_msg_buf(i2c_common->dma_buf, i2c_common->msg, true);75}76 77static void i2c_amd_start_cmd(struct amd_i2c_dev *i2c_dev)78{79 struct amd_i2c_common *i2c_common = &i2c_dev->common;80 81 reinit_completion(&i2c_dev->cmd_complete);82 i2c_common->cmd_success = false;83}84 85static void i2c_amd_cmd_completion(struct amd_i2c_common *i2c_common)86{87 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);88 union i2c_event *event = &i2c_common->eventval;89 90 if (event->r.status == i2c_readcomplete_event)91 dev_dbg(&i2c_dev->pdev->dev, "readdata:%*ph\n", event->r.length,92 i2c_common->msg->buf);93 94 complete(&i2c_dev->cmd_complete);95}96 97static int i2c_amd_check_cmd_completion(struct amd_i2c_dev *i2c_dev)98{99 struct amd_i2c_common *i2c_common = &i2c_dev->common;100 unsigned long time_left;101 102 time_left = wait_for_completion_timeout(&i2c_dev->cmd_complete,103 i2c_dev->adap.timeout);104 105 if ((i2c_common->reqcmd == i2c_read ||106 i2c_common->reqcmd == i2c_write) &&107 i2c_common->msg->len > 32)108 i2c_amd_dma_unmap(i2c_common);109 110 if (time_left == 0) {111 amd_mp2_rw_timeout(i2c_common);112 return -ETIMEDOUT;113 }114 115 amd_mp2_process_event(i2c_common);116 117 if (!i2c_common->cmd_success)118 return -EIO;119 120 return 0;121}122 123static int i2c_amd_enable_set(struct amd_i2c_dev *i2c_dev, bool enable)124{125 struct amd_i2c_common *i2c_common = &i2c_dev->common;126 127 i2c_amd_start_cmd(i2c_dev);128 amd_mp2_bus_enable_set(i2c_common, enable);129 130 return i2c_amd_check_cmd_completion(i2c_dev);131}132 133static int i2c_amd_xfer_msg(struct amd_i2c_dev *i2c_dev, struct i2c_msg *pmsg)134{135 struct amd_i2c_common *i2c_common = &i2c_dev->common;136 137 i2c_amd_start_cmd(i2c_dev);138 i2c_common->msg = pmsg;139 140 if (pmsg->len > 32)141 if (i2c_amd_dma_map(i2c_common))142 return -EIO;143 144 if (pmsg->flags & I2C_M_RD)145 amd_mp2_rw(i2c_common, i2c_read);146 else147 amd_mp2_rw(i2c_common, i2c_write);148 149 return i2c_amd_check_cmd_completion(i2c_dev);150}151 152static int i2c_amd_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs, int num)153{154 struct amd_i2c_dev *i2c_dev = i2c_get_adapdata(adap);155 int i;156 struct i2c_msg *pmsg;157 int err = 0;158 159 /* the adapter might have been deleted while waiting for the bus lock */160 if (unlikely(!i2c_dev->common.mp2_dev))161 return -EINVAL;162 163 amd_mp2_pm_runtime_get(i2c_dev->common.mp2_dev);164 165 for (i = 0; i < num; i++) {166 pmsg = &msgs[i];167 err = i2c_amd_xfer_msg(i2c_dev, pmsg);168 if (err)169 break;170 }171 172 amd_mp2_pm_runtime_put(i2c_dev->common.mp2_dev);173 return err ? err : num;174}175 176static u32 i2c_amd_func(struct i2c_adapter *a)177{178 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;179}180 181static const struct i2c_algorithm i2c_amd_algorithm = {182 .master_xfer = i2c_amd_xfer,183 .functionality = i2c_amd_func,184};185 186#ifdef CONFIG_PM187static int i2c_amd_suspend(struct amd_i2c_common *i2c_common)188{189 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);190 191 i2c_amd_enable_set(i2c_dev, false);192 return 0;193}194 195static int i2c_amd_resume(struct amd_i2c_common *i2c_common)196{197 struct amd_i2c_dev *i2c_dev = amd_i2c_dev_common(i2c_common);198 199 return i2c_amd_enable_set(i2c_dev, true);200}201#endif202 203static const u32 supported_speeds[] = {204 I2C_MAX_HIGH_SPEED_MODE_FREQ,205 I2C_MAX_TURBO_MODE_FREQ,206 I2C_MAX_FAST_MODE_PLUS_FREQ,207 I2C_MAX_FAST_MODE_FREQ,208 I2C_MAX_STANDARD_MODE_FREQ,209};210 211static enum speed_enum i2c_amd_get_bus_speed(struct platform_device *pdev)212{213 u32 acpi_speed;214 int i;215 216 acpi_speed = i2c_acpi_find_bus_speed(&pdev->dev);217 /* round down to the lowest standard speed */218 for (i = 0; i < ARRAY_SIZE(supported_speeds); i++) {219 if (acpi_speed >= supported_speeds[i])220 break;221 }222 acpi_speed = i < ARRAY_SIZE(supported_speeds) ? supported_speeds[i] : 0;223 224 switch (acpi_speed) {225 case I2C_MAX_STANDARD_MODE_FREQ:226 return speed100k;227 case I2C_MAX_FAST_MODE_FREQ:228 return speed400k;229 case I2C_MAX_FAST_MODE_PLUS_FREQ:230 return speed1000k;231 case I2C_MAX_TURBO_MODE_FREQ:232 return speed1400k;233 case I2C_MAX_HIGH_SPEED_MODE_FREQ:234 return speed3400k;235 default:236 return speed400k;237 }238}239 240static const struct i2c_adapter_quirks amd_i2c_dev_quirks = {241 .max_read_len = AMD_MP2_I2C_MAX_RW_LENGTH,242 .max_write_len = AMD_MP2_I2C_MAX_RW_LENGTH,243};244 245static int i2c_amd_probe(struct platform_device *pdev)246{247 struct device *dev = &pdev->dev;248 int ret;249 struct amd_i2c_dev *i2c_dev;250 struct amd_mp2_dev *mp2_dev;251 u64 uid;252 253 ret = acpi_dev_uid_to_integer(ACPI_COMPANION(dev), &uid);254 if (ret)255 return dev_err_probe(dev, ret, "missing UID/bus id!\n");256 if (uid >= 2)257 return dev_err_probe(dev, -EINVAL, "incorrect UID/bus id \"%llu\"!\n", uid);258 dev_dbg(dev, "bus id is %llu\n", uid);259 260 /* The ACPI namespace doesn't contain information about which MP2 PCI261 * device an AMDI0011 ACPI device is related to, so assume that there's262 * only one MP2 PCI device per system.263 */264 mp2_dev = amd_mp2_find_device();265 if (!mp2_dev || !mp2_dev->probed)266 /* The MP2 PCI device should get probed later */267 return -EPROBE_DEFER;268 269 i2c_dev = devm_kzalloc(&pdev->dev, sizeof(*i2c_dev), GFP_KERNEL);270 if (!i2c_dev)271 return -ENOMEM;272 273 i2c_dev->common.bus_id = uid;274 i2c_dev->common.mp2_dev = mp2_dev;275 i2c_dev->pdev = pdev;276 platform_set_drvdata(pdev, i2c_dev);277 278 i2c_dev->common.cmd_completion = &i2c_amd_cmd_completion;279#ifdef CONFIG_PM280 i2c_dev->common.suspend = &i2c_amd_suspend;281 i2c_dev->common.resume = &i2c_amd_resume;282#endif283 284 /* Register the adapter */285 amd_mp2_pm_runtime_get(mp2_dev);286 287 i2c_dev->common.reqcmd = i2c_none;288 if (amd_mp2_register_cb(&i2c_dev->common))289 return -EINVAL;290 device_link_add(&i2c_dev->pdev->dev, &mp2_dev->pci_dev->dev,291 DL_FLAG_AUTOREMOVE_CONSUMER);292 293 i2c_dev->common.i2c_speed = i2c_amd_get_bus_speed(pdev);294 295 /* Setup i2c adapter description */296 i2c_dev->adap.owner = THIS_MODULE;297 i2c_dev->adap.algo = &i2c_amd_algorithm;298 i2c_dev->adap.quirks = &amd_i2c_dev_quirks;299 i2c_dev->adap.dev.parent = &pdev->dev;300 i2c_dev->adap.algo_data = i2c_dev;301 i2c_dev->adap.timeout = AMD_I2C_TIMEOUT;302 ACPI_COMPANION_SET(&i2c_dev->adap.dev, ACPI_COMPANION(&pdev->dev));303 i2c_dev->adap.dev.of_node = pdev->dev.of_node;304 snprintf(i2c_dev->adap.name, sizeof(i2c_dev->adap.name),305 "AMD MP2 i2c bus %u", i2c_dev->common.bus_id);306 i2c_set_adapdata(&i2c_dev->adap, i2c_dev);307 308 init_completion(&i2c_dev->cmd_complete);309 310 /* Enable the bus */311 if (i2c_amd_enable_set(i2c_dev, true))312 dev_err(&pdev->dev, "initial bus enable failed\n");313 314 /* Attach to the i2c layer */315 ret = i2c_add_adapter(&i2c_dev->adap);316 317 amd_mp2_pm_runtime_put(mp2_dev);318 319 if (ret < 0)320 dev_err(&pdev->dev, "i2c add adapter failed = %d\n", ret);321 322 return ret;323}324 325static void i2c_amd_remove(struct platform_device *pdev)326{327 struct amd_i2c_dev *i2c_dev = platform_get_drvdata(pdev);328 struct amd_i2c_common *i2c_common = &i2c_dev->common;329 330 i2c_lock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);331 332 i2c_amd_enable_set(i2c_dev, false);333 amd_mp2_unregister_cb(i2c_common);334 i2c_common->mp2_dev = NULL;335 336 i2c_unlock_bus(&i2c_dev->adap, I2C_LOCK_ROOT_ADAPTER);337 338 i2c_del_adapter(&i2c_dev->adap);339}340 341static const struct acpi_device_id i2c_amd_acpi_match[] = {342 { "AMDI0011" },343 { }344};345MODULE_DEVICE_TABLE(acpi, i2c_amd_acpi_match);346 347static struct platform_driver i2c_amd_plat_driver = {348 .probe = i2c_amd_probe,349 .remove_new = i2c_amd_remove,350 .driver = {351 .name = "i2c_amd_mp2",352 .acpi_match_table = ACPI_PTR(i2c_amd_acpi_match),353 },354};355module_platform_driver(i2c_amd_plat_driver);356 357MODULE_DESCRIPTION("AMD(R) MP2 I2C Platform Driver");358MODULE_AUTHOR("Nehal Shah <nehal-bakulchandra.shah@amd.com>");359MODULE_AUTHOR("Elie Morisse <syniurge@gmail.com>");360MODULE_LICENSE("Dual BSD/GPL");361