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 "phy_common.h" 19 20 #define S3FWRN5_I2C_DRIVER_NAME "s3fwrn5_i2c" 21 22 struct s3fwrn5_i2c_phy { 23 struct phy_common common; 24 struct i2c_client *i2c_dev; 25 26 unsigned int irq_skip:1; 27 }; 28 29 static void s3fwrn5_i2c_set_mode(void *phy_id, enum s3fwrn5_mode mode) 30 { 31 struct s3fwrn5_i2c_phy *phy = phy_id; 32 33 mutex_lock(&phy->common.mutex); 34 35 if (s3fwrn5_phy_power_ctrl(&phy->common, mode) == false) 36 goto out; 37 38 phy->irq_skip = true; 39 40 out: 41 mutex_unlock(&phy->common.mutex); 42 } 43 44 static int s3fwrn5_i2c_write(void *phy_id, struct sk_buff *skb) 45 { 46 struct s3fwrn5_i2c_phy *phy = phy_id; 47 int ret; 48 49 mutex_lock(&phy->common.mutex); 50 51 phy->irq_skip = false; 52 53 ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len); 54 if (ret == -EREMOTEIO) { 55 /* Retry, chip was in standby */ 56 usleep_range(110000, 120000); 57 ret = i2c_master_send(phy->i2c_dev, skb->data, skb->len); 58 } 59 60 mutex_unlock(&phy->common.mutex); 61 62 if (ret < 0) 63 return ret; 64 65 if (ret != skb->len) 66 return -EREMOTEIO; 67 68 return 0; 69 } 70 71 static const struct s3fwrn5_phy_ops i2c_phy_ops = { 72 .set_wake = s3fwrn5_phy_set_wake, 73 .set_mode = s3fwrn5_i2c_set_mode, 74 .get_mode = s3fwrn5_phy_get_mode, 75 .write = s3fwrn5_i2c_write, 76 }; 77 78 static int s3fwrn5_i2c_read(struct s3fwrn5_i2c_phy *phy) 79 { 80 struct sk_buff *skb; 81 size_t hdr_size; 82 size_t data_len; 83 char hdr[4]; 84 int ret; 85 86 hdr_size = (phy->common.mode == S3FWRN5_MODE_NCI) ? 87 NCI_CTRL_HDR_SIZE : S3FWRN5_FW_HDR_SIZE; 88 ret = i2c_master_recv(phy->i2c_dev, hdr, hdr_size); 89 if (ret < 0) 90 return ret; 91 92 if (ret < hdr_size) 93 return -EBADMSG; 94 95 data_len = (phy->common.mode == S3FWRN5_MODE_NCI) ? 96 ((struct nci_ctrl_hdr *)hdr)->plen : 97 ((struct s3fwrn5_fw_header *)hdr)->len; 98 99 skb = alloc_skb(hdr_size + data_len, GFP_KERNEL); 100 if (!skb) 101 return -ENOMEM; 102 103 skb_put_data(skb, hdr, hdr_size); 104 105 if (data_len == 0) 106 goto out; 107 108 ret = i2c_master_recv(phy->i2c_dev, skb_put(skb, data_len), data_len); 109 if (ret != data_len) { 110 kfree_skb(skb); 111 return -EBADMSG; 112 } 113 114 out: 115 return s3fwrn5_recv_frame(phy->common.ndev, skb, phy->common.mode); 116 } 117 118 static irqreturn_t s3fwrn5_i2c_irq_thread_fn(int irq, void *phy_id) 119 { 120 struct s3fwrn5_i2c_phy *phy = phy_id; 121 122 if (!phy || !phy->common.ndev) { 123 WARN_ON_ONCE(1); 124 return IRQ_NONE; 125 } 126 127 mutex_lock(&phy->common.mutex); 128 129 if (phy->irq_skip) 130 goto out; 131 132 switch (phy->common.mode) { 133 case S3FWRN5_MODE_NCI: 134 case S3FWRN5_MODE_FW: 135 s3fwrn5_i2c_read(phy); 136 break; 137 case S3FWRN5_MODE_COLD: 138 break; 139 } 140 141 out: 142 mutex_unlock(&phy->common.mutex); 143 144 return IRQ_HANDLED; 145 } 146 147 static int s3fwrn5_i2c_parse_dt(struct i2c_client *client) 148 { 149 struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client); 150 struct device_node *np = client->dev.of_node; 151 152 if (!np) 153 return -ENODEV; 154 155 phy->common.gpio_en = of_get_named_gpio(np, "en-gpios", 0); 156 if (!gpio_is_valid(phy->common.gpio_en)) { 157 /* Support also deprecated property */ 158 phy->common.gpio_en = of_get_named_gpio(np, 159 "s3fwrn5,en-gpios", 160 0); 161 if (!gpio_is_valid(phy->common.gpio_en)) 162 return -ENODEV; 163 } 164 165 phy->common.gpio_fw_wake = of_get_named_gpio(np, "wake-gpios", 0); 166 if (!gpio_is_valid(phy->common.gpio_fw_wake)) { 167 /* Support also deprecated property */ 168 phy->common.gpio_fw_wake = of_get_named_gpio(np, 169 "s3fwrn5,fw-gpios", 170 0); 171 if (!gpio_is_valid(phy->common.gpio_fw_wake)) 172 return -ENODEV; 173 } 174 175 return 0; 176 } 177 178 static int s3fwrn5_i2c_probe(struct i2c_client *client, 179 const struct i2c_device_id *id) 180 { 181 struct s3fwrn5_i2c_phy *phy; 182 int ret; 183 184 phy = devm_kzalloc(&client->dev, sizeof(*phy), GFP_KERNEL); 185 if (!phy) 186 return -ENOMEM; 187 188 mutex_init(&phy->common.mutex); 189 phy->common.mode = S3FWRN5_MODE_COLD; 190 phy->irq_skip = true; 191 192 phy->i2c_dev = client; 193 i2c_set_clientdata(client, phy); 194 195 ret = s3fwrn5_i2c_parse_dt(client); 196 if (ret < 0) 197 return ret; 198 199 ret = devm_gpio_request_one(&phy->i2c_dev->dev, phy->common.gpio_en, 200 GPIOF_OUT_INIT_HIGH, "s3fwrn5_en"); 201 if (ret < 0) 202 return ret; 203 204 ret = devm_gpio_request_one(&phy->i2c_dev->dev, 205 phy->common.gpio_fw_wake, 206 GPIOF_OUT_INIT_LOW, "s3fwrn5_fw_wake"); 207 if (ret < 0) 208 return ret; 209 210 ret = s3fwrn5_probe(&phy->common.ndev, phy, &phy->i2c_dev->dev, 211 &i2c_phy_ops); 212 if (ret < 0) 213 return ret; 214 215 ret = devm_request_threaded_irq(&client->dev, phy->i2c_dev->irq, NULL, 216 s3fwrn5_i2c_irq_thread_fn, IRQF_ONESHOT, 217 S3FWRN5_I2C_DRIVER_NAME, phy); 218 if (ret) 219 s3fwrn5_remove(phy->common.ndev); 220 221 return ret; 222 } 223 224 static int s3fwrn5_i2c_remove(struct i2c_client *client) 225 { 226 struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client); 227 228 s3fwrn5_remove(phy->common.ndev); 229 230 return 0; 231 } 232 233 static const struct i2c_device_id s3fwrn5_i2c_id_table[] = { 234 {S3FWRN5_I2C_DRIVER_NAME, 0}, 235 {} 236 }; 237 MODULE_DEVICE_TABLE(i2c, s3fwrn5_i2c_id_table); 238 239 static const struct of_device_id of_s3fwrn5_i2c_match[] = { 240 { .compatible = "samsung,s3fwrn5-i2c", }, 241 {} 242 }; 243 MODULE_DEVICE_TABLE(of, of_s3fwrn5_i2c_match); 244 245 static struct i2c_driver s3fwrn5_i2c_driver = { 246 .driver = { 247 .name = S3FWRN5_I2C_DRIVER_NAME, 248 .of_match_table = of_match_ptr(of_s3fwrn5_i2c_match), 249 }, 250 .probe = s3fwrn5_i2c_probe, 251 .remove = s3fwrn5_i2c_remove, 252 .id_table = s3fwrn5_i2c_id_table, 253 }; 254 255 module_i2c_driver(s3fwrn5_i2c_driver); 256 257 MODULE_LICENSE("GPL"); 258 MODULE_DESCRIPTION("I2C driver for Samsung S3FWRN5"); 259 MODULE_AUTHOR("Robert Baldyga <r.baldyga@samsung.com>"); 260