257 lines · c
1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Driver for the Diolan DLN-2 USB-I2C adapter4 *5 * Copyright (c) 2014 Intel Corporation6 *7 * Derived from:8 * i2c-diolan-u2c.c9 * Copyright (c) 2010-2011 Ericsson AB10 */11 12#include <linux/kernel.h>13#include <linux/module.h>14#include <linux/types.h>15#include <linux/slab.h>16#include <linux/i2c.h>17#include <linux/platform_device.h>18#include <linux/mfd/dln2.h>19#include <linux/acpi.h>20 21#define DLN2_I2C_MODULE_ID 0x0322#define DLN2_I2C_CMD(cmd) DLN2_CMD(cmd, DLN2_I2C_MODULE_ID)23 24/* I2C commands */25#define DLN2_I2C_GET_PORT_COUNT DLN2_I2C_CMD(0x00)26#define DLN2_I2C_ENABLE DLN2_I2C_CMD(0x01)27#define DLN2_I2C_DISABLE DLN2_I2C_CMD(0x02)28#define DLN2_I2C_IS_ENABLED DLN2_I2C_CMD(0x03)29#define DLN2_I2C_WRITE DLN2_I2C_CMD(0x06)30#define DLN2_I2C_READ DLN2_I2C_CMD(0x07)31#define DLN2_I2C_SCAN_DEVICES DLN2_I2C_CMD(0x08)32#define DLN2_I2C_PULLUP_ENABLE DLN2_I2C_CMD(0x09)33#define DLN2_I2C_PULLUP_DISABLE DLN2_I2C_CMD(0x0A)34#define DLN2_I2C_PULLUP_IS_ENABLED DLN2_I2C_CMD(0x0B)35#define DLN2_I2C_TRANSFER DLN2_I2C_CMD(0x0C)36#define DLN2_I2C_SET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0D)37#define DLN2_I2C_GET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0E)38 39#define DLN2_I2C_MAX_XFER_SIZE 25640#define DLN2_I2C_BUF_SIZE (DLN2_I2C_MAX_XFER_SIZE + 16)41 42struct dln2_i2c {43 struct platform_device *pdev;44 struct i2c_adapter adapter;45 u8 port;46 /*47 * Buffer to hold the packet for read or write transfers. One is enough48 * since we can't have multiple transfers in parallel on the i2c bus.49 */50 void *buf;51};52 53static int dln2_i2c_enable(struct dln2_i2c *dln2, bool enable)54{55 u16 cmd;56 struct {57 u8 port;58 } tx;59 60 tx.port = dln2->port;61 62 if (enable)63 cmd = DLN2_I2C_ENABLE;64 else65 cmd = DLN2_I2C_DISABLE;66 67 return dln2_transfer_tx(dln2->pdev, cmd, &tx, sizeof(tx));68}69 70static int dln2_i2c_write(struct dln2_i2c *dln2, u8 addr,71 u8 *data, u16 data_len)72{73 int ret;74 struct {75 u8 port;76 u8 addr;77 u8 mem_addr_len;78 __le32 mem_addr;79 __le16 buf_len;80 u8 buf[DLN2_I2C_MAX_XFER_SIZE];81 } __packed *tx = dln2->buf;82 unsigned len;83 84 BUILD_BUG_ON(sizeof(*tx) > DLN2_I2C_BUF_SIZE);85 86 tx->port = dln2->port;87 tx->addr = addr;88 tx->mem_addr_len = 0;89 tx->mem_addr = 0;90 tx->buf_len = cpu_to_le16(data_len);91 memcpy(tx->buf, data, data_len);92 93 len = sizeof(*tx) + data_len - DLN2_I2C_MAX_XFER_SIZE;94 ret = dln2_transfer_tx(dln2->pdev, DLN2_I2C_WRITE, tx, len);95 if (ret < 0)96 return ret;97 98 return data_len;99}100 101static int dln2_i2c_read(struct dln2_i2c *dln2, u16 addr, u8 *data,102 u16 data_len)103{104 int ret;105 struct {106 u8 port;107 u8 addr;108 u8 mem_addr_len;109 __le32 mem_addr;110 __le16 buf_len;111 } __packed tx;112 struct {113 __le16 buf_len;114 u8 buf[DLN2_I2C_MAX_XFER_SIZE];115 } __packed *rx = dln2->buf;116 unsigned rx_len = sizeof(*rx);117 118 BUILD_BUG_ON(sizeof(*rx) > DLN2_I2C_BUF_SIZE);119 120 tx.port = dln2->port;121 tx.addr = addr;122 tx.mem_addr_len = 0;123 tx.mem_addr = 0;124 tx.buf_len = cpu_to_le16(data_len);125 126 ret = dln2_transfer(dln2->pdev, DLN2_I2C_READ, &tx, sizeof(tx),127 rx, &rx_len);128 if (ret < 0)129 return ret;130 if (rx_len < sizeof(rx->buf_len) + data_len)131 return -EPROTO;132 if (le16_to_cpu(rx->buf_len) != data_len)133 return -EPROTO;134 135 memcpy(data, rx->buf, data_len);136 137 return data_len;138}139 140static int dln2_i2c_xfer(struct i2c_adapter *adapter,141 struct i2c_msg *msgs, int num)142{143 struct dln2_i2c *dln2 = i2c_get_adapdata(adapter);144 struct i2c_msg *pmsg;145 int i;146 147 for (i = 0; i < num; i++) {148 int ret;149 150 pmsg = &msgs[i];151 152 if (pmsg->flags & I2C_M_RD) {153 ret = dln2_i2c_read(dln2, pmsg->addr, pmsg->buf,154 pmsg->len);155 if (ret < 0)156 return ret;157 158 pmsg->len = ret;159 } else {160 ret = dln2_i2c_write(dln2, pmsg->addr, pmsg->buf,161 pmsg->len);162 if (ret != pmsg->len)163 return -EPROTO;164 }165 }166 167 return num;168}169 170static u32 dln2_i2c_func(struct i2c_adapter *a)171{172 return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA |173 I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL |174 I2C_FUNC_SMBUS_I2C_BLOCK;175}176 177static const struct i2c_algorithm dln2_i2c_usb_algorithm = {178 .xfer = dln2_i2c_xfer,179 .functionality = dln2_i2c_func,180};181 182static const struct i2c_adapter_quirks dln2_i2c_quirks = {183 .max_read_len = DLN2_I2C_MAX_XFER_SIZE,184 .max_write_len = DLN2_I2C_MAX_XFER_SIZE,185};186 187static int dln2_i2c_probe(struct platform_device *pdev)188{189 int ret;190 struct dln2_i2c *dln2;191 struct device *dev = &pdev->dev;192 struct dln2_platform_data *pdata = dev_get_platdata(&pdev->dev);193 194 dln2 = devm_kzalloc(dev, sizeof(*dln2), GFP_KERNEL);195 if (!dln2)196 return -ENOMEM;197 198 dln2->buf = devm_kmalloc(dev, DLN2_I2C_BUF_SIZE, GFP_KERNEL);199 if (!dln2->buf)200 return -ENOMEM;201 202 dln2->pdev = pdev;203 dln2->port = pdata->port;204 205 /* setup i2c adapter description */206 dln2->adapter.owner = THIS_MODULE;207 dln2->adapter.class = I2C_CLASS_HWMON;208 dln2->adapter.algo = &dln2_i2c_usb_algorithm;209 dln2->adapter.quirks = &dln2_i2c_quirks;210 dln2->adapter.dev.parent = dev;211 ACPI_COMPANION_SET(&dln2->adapter.dev, ACPI_COMPANION(&pdev->dev));212 dln2->adapter.dev.of_node = dev->of_node;213 i2c_set_adapdata(&dln2->adapter, dln2);214 snprintf(dln2->adapter.name, sizeof(dln2->adapter.name), "%s-%s-%d",215 "dln2-i2c", dev_name(pdev->dev.parent), dln2->port);216 217 platform_set_drvdata(pdev, dln2);218 219 /* initialize the i2c interface */220 ret = dln2_i2c_enable(dln2, true);221 if (ret < 0)222 return dev_err_probe(dev, ret, "failed to initialize adapter\n");223 224 /* and finally attach to i2c layer */225 ret = i2c_add_adapter(&dln2->adapter);226 if (ret < 0)227 goto out_disable;228 229 return 0;230 231out_disable:232 dln2_i2c_enable(dln2, false);233 234 return ret;235}236 237static void dln2_i2c_remove(struct platform_device *pdev)238{239 struct dln2_i2c *dln2 = platform_get_drvdata(pdev);240 241 i2c_del_adapter(&dln2->adapter);242 dln2_i2c_enable(dln2, false);243}244 245static struct platform_driver dln2_i2c_driver = {246 .driver.name = "dln2-i2c",247 .probe = dln2_i2c_probe,248 .remove_new = dln2_i2c_remove,249};250 251module_platform_driver(dln2_i2c_driver);252 253MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@intel.com>");254MODULE_DESCRIPTION("Driver for the Diolan DLN2 I2C controller interface");255MODULE_LICENSE("GPL v2");256MODULE_ALIAS("platform:dln2-i2c");257