1 // SPDX-License-Identifier: GPL-2.0+ 2 /* 3 * UART Link Layer for S3FWRN82 NCI based Driver 4 * 5 * Copyright (C) 2015 Samsung Electronics 6 * Robert Baldyga <r.baldyga@samsung.com> 7 * Copyright (C) 2020 Samsung Electronics 8 * Bongsu Jeon <bongsu.jeon@samsung.com> 9 */ 10 11 #include <linux/device.h> 12 #include <linux/kernel.h> 13 #include <linux/module.h> 14 #include <linux/nfc.h> 15 #include <linux/netdevice.h> 16 #include <linux/of.h> 17 #include <linux/serdev.h> 18 #include <linux/gpio.h> 19 #include <linux/of_gpio.h> 20 21 #include "phy_common.h" 22 23 #define S3FWRN82_NCI_HEADER 3 24 #define S3FWRN82_NCI_IDX 2 25 #define NCI_SKB_BUFF_LEN 258 26 27 struct s3fwrn82_uart_phy { 28 struct phy_common common; 29 struct serdev_device *ser_dev; 30 struct sk_buff *recv_skb; 31 }; 32 33 static int s3fwrn82_uart_write(void *phy_id, struct sk_buff *out) 34 { 35 struct s3fwrn82_uart_phy *phy = phy_id; 36 int err; 37 38 err = serdev_device_write(phy->ser_dev, 39 out->data, out->len, 40 MAX_SCHEDULE_TIMEOUT); 41 if (err < 0) 42 return err; 43 44 return 0; 45 } 46 47 static const struct s3fwrn5_phy_ops uart_phy_ops = { 48 .set_wake = s3fwrn5_phy_set_wake, 49 .set_mode = s3fwrn5_phy_set_mode, 50 .get_mode = s3fwrn5_phy_get_mode, 51 .write = s3fwrn82_uart_write, 52 }; 53 54 static int s3fwrn82_uart_read(struct serdev_device *serdev, 55 const unsigned char *data, 56 size_t count) 57 { 58 struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev); 59 size_t i; 60 61 for (i = 0; i < count; i++) { 62 skb_put_u8(phy->recv_skb, *data++); 63 64 if (phy->recv_skb->len < S3FWRN82_NCI_HEADER) 65 continue; 66 67 if ((phy->recv_skb->len - S3FWRN82_NCI_HEADER) 68 < phy->recv_skb->data[S3FWRN82_NCI_IDX]) 69 continue; 70 71 s3fwrn5_recv_frame(phy->common.ndev, phy->recv_skb, 72 phy->common.mode); 73 phy->recv_skb = alloc_skb(NCI_SKB_BUFF_LEN, GFP_KERNEL); 74 if (!phy->recv_skb) 75 return 0; 76 } 77 78 return i; 79 } 80 81 static const struct serdev_device_ops s3fwrn82_serdev_ops = { 82 .receive_buf = s3fwrn82_uart_read, 83 .write_wakeup = serdev_device_write_wakeup, 84 }; 85 86 static const struct of_device_id s3fwrn82_uart_of_match[] = { 87 { .compatible = "samsung,s3fwrn82", }, 88 {}, 89 }; 90 MODULE_DEVICE_TABLE(of, s3fwrn82_uart_of_match); 91 92 static int s3fwrn82_uart_parse_dt(struct serdev_device *serdev) 93 { 94 struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev); 95 struct device_node *np = serdev->dev.of_node; 96 97 if (!np) 98 return -ENODEV; 99 100 phy->common.gpio_en = of_get_named_gpio(np, "en-gpios", 0); 101 if (!gpio_is_valid(phy->common.gpio_en)) 102 return -ENODEV; 103 104 phy->common.gpio_fw_wake = of_get_named_gpio(np, "wake-gpios", 0); 105 if (!gpio_is_valid(phy->common.gpio_fw_wake)) 106 return -ENODEV; 107 108 return 0; 109 } 110 111 static int s3fwrn82_uart_probe(struct serdev_device *serdev) 112 { 113 struct s3fwrn82_uart_phy *phy; 114 int ret = -ENOMEM; 115 116 phy = devm_kzalloc(&serdev->dev, sizeof(*phy), GFP_KERNEL); 117 if (!phy) 118 goto err_exit; 119 120 phy->recv_skb = alloc_skb(NCI_SKB_BUFF_LEN, GFP_KERNEL); 121 if (!phy->recv_skb) 122 goto err_exit; 123 124 mutex_init(&phy->common.mutex); 125 phy->common.mode = S3FWRN5_MODE_COLD; 126 127 phy->ser_dev = serdev; 128 serdev_device_set_drvdata(serdev, phy); 129 serdev_device_set_client_ops(serdev, &s3fwrn82_serdev_ops); 130 ret = serdev_device_open(serdev); 131 if (ret) { 132 dev_err(&serdev->dev, "Unable to open device\n"); 133 goto err_skb; 134 } 135 136 ret = serdev_device_set_baudrate(serdev, 115200); 137 if (ret != 115200) { 138 ret = -EINVAL; 139 goto err_serdev; 140 } 141 142 serdev_device_set_flow_control(serdev, false); 143 144 ret = s3fwrn82_uart_parse_dt(serdev); 145 if (ret < 0) 146 goto err_serdev; 147 148 ret = devm_gpio_request_one(&phy->ser_dev->dev, phy->common.gpio_en, 149 GPIOF_OUT_INIT_HIGH, "s3fwrn82_en"); 150 if (ret < 0) 151 goto err_serdev; 152 153 ret = devm_gpio_request_one(&phy->ser_dev->dev, 154 phy->common.gpio_fw_wake, 155 GPIOF_OUT_INIT_LOW, "s3fwrn82_fw_wake"); 156 if (ret < 0) 157 goto err_serdev; 158 159 ret = s3fwrn5_probe(&phy->common.ndev, phy, &phy->ser_dev->dev, 160 &uart_phy_ops); 161 if (ret < 0) 162 goto err_serdev; 163 164 return ret; 165 166 err_serdev: 167 serdev_device_close(serdev); 168 err_skb: 169 kfree_skb(phy->recv_skb); 170 err_exit: 171 return ret; 172 } 173 174 static void s3fwrn82_uart_remove(struct serdev_device *serdev) 175 { 176 struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev); 177 178 s3fwrn5_remove(phy->common.ndev); 179 serdev_device_close(serdev); 180 kfree_skb(phy->recv_skb); 181 } 182 183 static struct serdev_device_driver s3fwrn82_uart_driver = { 184 .probe = s3fwrn82_uart_probe, 185 .remove = s3fwrn82_uart_remove, 186 .driver = { 187 .name = "s3fwrn82_uart", 188 .of_match_table = s3fwrn82_uart_of_match, 189 }, 190 }; 191 192 module_serdev_device_driver(s3fwrn82_uart_driver); 193 194 MODULE_LICENSE("GPL"); 195 MODULE_DESCRIPTION("UART driver for Samsung NFC"); 196 MODULE_AUTHOR("Bongsu Jeon <bongsu.jeon@samsung.com>"); 197