1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * I2C Link Layer for Samsung S3FWRN5 NCI based Driver 4 * 5 * Copyright (C) 2015 Samsung Electrnoics 6 * Robert Baldyga <r.baldyga@samsung.com> 7 */ 8 9 #include <linux/i2c.h> 10 #include <linux/gpio.h> 11 #include <linux/delay.h> 12 #include <linux/of_gpio.h> 13 #include <linux/of_irq.h> 14 #include <linux/module.h> 15 16 #include <net/nfc/nfc.h> 17 18 #include "s3fwrn5.h" 19 20 #define S3FWRN5_I2C_DRIVER_NAME "s3fwrn5_i2c" 21 22 #define S3FWRN5_I2C_MAX_PAYLOAD 32 23 #define S3FWRN5_EN_WAIT_TIME 150 24 25 struct s3fwrn5_i2c_phy { 26 struct i2c_client *i2c_dev; 27 struct nci_dev *ndev; 28 29 unsigned int gpio_en; 30 unsigned int gpio_fw_wake; 31 32 struct mutex mutex; 33 34 enum s3fwrn5_mode mode; 35 unsigned int irq_skip:1; 36 }; 37 38 static void s3fwrn5_i2c_set_wake(void *phy_id, bool wake) 39 { 40 struct s3fwrn5_i2c_phy *phy = phy_id; 41 42 mutex_lock(&phy->mutex); 43 gpio_set_value(phy->gpio_fw_wake, wake); 44 msleep(S3FWRN5_EN_WAIT_TIME/2); 45 mutex_unlock(&phy->mutex); 46 } 47 48 static void s3fwrn5_i2c_set_mode(void *phy_id, enum s3fwrn5_mode mode) 49 { 50 struct s3fwrn5_i2c_phy *phy = phy_id; 51 52 mutex_lock(&phy->mutex); 53 54 if (phy->mode == mode) 55 goto out; 56 57 phy->mode = mode; 58 59 gpio_set_value(phy->gpio_en, 1); 60 gpio_set_value(phy->gpio_fw_wake, 0); 61 if (mode == S3FWRN5_MODE_FW) 62 gpio_set_value(phy->gpio_fw_wake, 1); 63 64 if (mode != S3FWRN5_MODE_COLD) { 65 msleep(S3FWRN5_EN_WAIT_TIME); 66 gpio_set_value(phy->gpio_en, 0); 67 msleep(S3FWRN5_EN_WAIT_TIME/2); 68 } 69 70 phy->irq_skip = true; 71 72 out: 73 mutex_unlock(&phy->mutex); 74 } 75 76 static enum s3fwrn5_mode s3fwrn5_i2c_get_mode(void *phy_id) 77 { 78 struct s3fwrn5_i2c_phy *phy = phy_id; 79 enum s3fwrn5_mode mode; 80 81 mutex_lock(&phy->mutex); 82 83 mode = phy->mode; 84 85 mutex_unlock(&phy->mutex); 86 87 return mode; 88 } 89 90 static int s3fwrn5_i2c_write(void *phy_id, struct sk_buff *skb) 91 { 92 struct s3fwrn5_i2c_phy *phy = phy_id; 93 int ret; 94 95 mutex_lock(&phy->mutex); 96 97 phy->irq_skip = false; 98 99 ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len); 100 if (ret == -EREMOTEIO) { 101 /* Retry, chip was in standby */ 102 usleep_range(110000, 120000); 103 ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len); 104 } 105 106 mutex_unlock(&phy->mutex); 107 108 if (ret < 0) 109 return ret; 110 111 if (ret != skb->len) 112 return -EREMOTEIO; 113 114 return 0; 115 } 116 117 static const struct s3fwrn5_phy_ops i2c_phy_ops = { 118 .set_wake = s3fwrn5_i2c_set_wake, 119 .set_mode = s3fwrn5_i2c_set_mode, 120 .get_mode = s3fwrn5_i2c_get_mode, 121 .write = s3fwrn5_i2c_write, 122 }; 123 124 static int s3fwrn5_i2c_read(struct s3fwrn5_i2c_phy *phy) 125 { 126 struct sk_buff *skb; 127 size_t hdr_size; 128 size_t data_len; 129 char hdr[4]; 130 int ret; 131 132 hdr_size = (phy->mode == S3FWRN5_MODE_NCI) ? 133 NCI_CTRL_HDR_SIZE : S3FWRN5_FW_HDR_SIZE; 134 ret = i2c_master_recv(phy->i2c_dev, hdr, hdr_size); 135 if (ret < 0) 136 return ret; 137 138 if (ret < hdr_size) 139 return -EBADMSG; 140 141 data_len = (phy->mode == S3FWRN5_MODE_NCI) ? 142 ((struct nci_ctrl_hdr *)hdr)->plen : 143 ((struct s3fwrn5_fw_header *)hdr)->len; 144 145 skb = alloc_skb(hdr_size + data_len, GFP_KERNEL); 146 if (!skb) 147 return -ENOMEM; 148 149 skb_put_data(skb, hdr, hdr_size); 150 151 if (data_len == 0) 152 goto out; 153 154 ret = i2c_master_recv(phy->i2c_dev, skb_put(skb, data_len), data_len); 155 if (ret != data_len) { 156 kfree_skb(skb); 157 return -EBADMSG; 158 } 159 160 out: 161 return s3fwrn5_recv_frame(phy->ndev, skb, phy->mode); 162 } 163 164 static irqreturn_t s3fwrn5_i2c_irq_thread_fn(int irq, void *phy_id) 165 { 166 struct s3fwrn5_i2c_phy *phy = phy_id; 167 int ret = 0; 168 169 if (!phy || !phy->ndev) { 170 WARN_ON_ONCE(1); 171 return IRQ_NONE; 172 } 173 174 mutex_lock(&phy->mutex); 175 176 if (phy->irq_skip) 177 goto out; 178 179 switch (phy->mode) { 180 case S3FWRN5_MODE_NCI: 181 case S3FWRN5_MODE_FW: 182 ret = s3fwrn5_i2c_read(phy); 183 break; 184 case S3FWRN5_MODE_COLD: 185 ret = -EREMOTEIO; 186 break; 187 } 188 189 out: 190 mutex_unlock(&phy->mutex); 191 192 return IRQ_HANDLED; 193 } 194 195 static int s3fwrn5_i2c_parse_dt(struct i2c_client *client) 196 { 197 struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client); 198 struct device_node *np = client->dev.of_node; 199 200 if (!np) 201 return -ENODEV; 202 203 phy->gpio_en = of_get_named_gpio(np, "s3fwrn5,en-gpios", 0); 204 if (!gpio_is_valid(phy->gpio_en)) 205 return -ENODEV; 206 207 phy->gpio_fw_wake = of_get_named_gpio(np, "s3fwrn5,fw-gpios", 0); 208 if (!gpio_is_valid(phy->gpio_fw_wake)) 209 return -ENODEV; 210 211 return 0; 212 } 213 214 static int s3fwrn5_i2c_probe(struct i2c_client *client, 215 const struct i2c_device_id *id) 216 { 217 struct s3fwrn5_i2c_phy *phy; 218 int ret; 219 220 phy = devm_kzalloc(&client->dev, sizeof(*phy), GFP_KERNEL); 221 if (!phy) 222 return -ENOMEM; 223 224 mutex_init(&phy->mutex); 225 phy->mode = S3FWRN5_MODE_COLD; 226 phy->irq_skip = true; 227 228 phy->i2c_dev = client; 229 i2c_set_clientdata(client, phy); 230 231 ret = s3fwrn5_i2c_parse_dt(client); 232 if (ret < 0) 233 return ret; 234 235 ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_en, 236 GPIOF_OUT_INIT_HIGH, "s3fwrn5_en"); 237 if (ret < 0) 238 return ret; 239 240 ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->gpio_fw_wake, 241 GPIOF_OUT_INIT_LOW, "s3fwrn5_fw_wake"); 242 if (ret < 0) 243 return ret; 244 245 ret = s3fwrn5_probe(&phy->ndev, phy, &phy->i2c_dev->dev, &i2c_phy_ops, 246 S3FWRN5_I2C_MAX_PAYLOAD); 247 if (ret < 0) 248 return ret; 249 250 ret = devm_request_threaded_irq(&client->dev, phy->i2c_dev->irq, NULL, 251 s3fwrn5_i2c_irq_thread_fn, IRQF_TRIGGER_HIGH | IRQF_ONESHOT, 252 S3FWRN5_I2C_DRIVER_NAME, phy); 253 if (ret) 254 s3fwrn5_remove(phy->ndev); 255 256 return ret; 257 } 258 259 static int s3fwrn5_i2c_remove(struct i2c_client *client) 260 { 261 struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client); 262 263 s3fwrn5_remove(phy->ndev); 264 265 return 0; 266 } 267 268 static const struct i2c_device_id s3fwrn5_i2c_id_table[] = { 269 {S3FWRN5_I2C_DRIVER_NAME, 0}, 270 {} 271 }; 272 MODULE_DEVICE_TABLE(i2c, s3fwrn5_i2c_id_table); 273 274 static const struct of_device_id of_s3fwrn5_i2c_match[] = { 275 { .compatible = "samsung,s3fwrn5-i2c", }, 276 {} 277 }; 278 MODULE_DEVICE_TABLE(of, of_s3fwrn5_i2c_match); 279 280 static struct i2c_driver s3fwrn5_i2c_driver = { 281 .driver = { 282 .name = S3FWRN5_I2C_DRIVER_NAME, 283 .of_match_table = of_match_ptr(of_s3fwrn5_i2c_match), 284 }, 285 .probe = s3fwrn5_i2c_probe, 286 .remove = s3fwrn5_i2c_remove, 287 .id_table = s3fwrn5_i2c_id_table, 288 }; 289 290 module_i2c_driver(s3fwrn5_i2c_driver); 291 292 MODULE_LICENSE("GPL"); 293 MODULE_DESCRIPTION("I2C driver for Samsung S3FWRN5"); 294 MODULE_AUTHOR("Robert Baldyga <r.baldyga@samsung.com>"); 295