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/mod_devicetable.h> 14 #include <linux/module.h> 15 #include <linux/nfc.h> 16 #include <linux/netdevice.h> 17 #include <linux/serdev.h> 18 #include <linux/gpio/consumer.h> 19 20 #include "phy_common.h" 21 22 #define S3FWRN82_NCI_HEADER 3 23 #define S3FWRN82_NCI_IDX 2 24 #define NCI_SKB_BUFF_LEN 258 25 26 struct s3fwrn82_uart_phy { 27 struct phy_common common; 28 struct serdev_device *ser_dev; 29 struct sk_buff *recv_skb; 30 }; 31 32 static int s3fwrn82_uart_write(void *phy_id, struct sk_buff *out) 33 { 34 struct s3fwrn82_uart_phy *phy = phy_id; 35 int err; 36 37 err = serdev_device_write(phy->ser_dev, 38 out->data, out->len, 39 MAX_SCHEDULE_TIMEOUT); 40 if (err < 0) 41 return err; 42 43 return 0; 44 } 45 46 static const struct s3fwrn5_phy_ops uart_phy_ops = { 47 .set_wake = s3fwrn5_phy_set_wake, 48 .set_mode = s3fwrn5_phy_set_mode, 49 .get_mode = s3fwrn5_phy_get_mode, 50 .write = s3fwrn82_uart_write, 51 }; 52 53 static size_t s3fwrn82_uart_read(struct serdev_device *serdev, 54 const u8 *data, size_t count) 55 { 56 struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev); 57 size_t i; 58 59 for (i = 0; i < count; i++) { 60 if (!phy->recv_skb) { 61 phy->recv_skb = alloc_skb(NCI_SKB_BUFF_LEN, GFP_KERNEL); 62 if (!phy->recv_skb) 63 return i; 64 } 65 66 skb_put_u8(phy->recv_skb, *data++); 67 68 if (phy->recv_skb->len < S3FWRN82_NCI_HEADER) 69 continue; 70 71 if ((phy->recv_skb->len - S3FWRN82_NCI_HEADER) 72 < phy->recv_skb->data[S3FWRN82_NCI_IDX]) 73 continue; 74 75 s3fwrn5_recv_frame(phy->common.ndev, phy->recv_skb, 76 phy->common.mode); 77 phy->recv_skb = NULL; 78 } 79 80 return i; 81 } 82 83 static const struct serdev_device_ops s3fwrn82_serdev_ops = { 84 .receive_buf = s3fwrn82_uart_read, 85 .write_wakeup = serdev_device_write_wakeup, 86 }; 87 88 static const struct of_device_id s3fwrn82_uart_of_match[] = { 89 { .compatible = "samsung,s3fwrn82", }, 90 {}, 91 }; 92 MODULE_DEVICE_TABLE(of, s3fwrn82_uart_of_match); 93 94 static int s3fwrn82_uart_probe(struct serdev_device *serdev) 95 { 96 struct s3fwrn82_uart_phy *phy; 97 int ret = -ENOMEM; 98 99 phy = devm_kzalloc(&serdev->dev, sizeof(*phy), GFP_KERNEL); 100 if (!phy) 101 goto err_exit; 102 103 phy->recv_skb = alloc_skb(NCI_SKB_BUFF_LEN, GFP_KERNEL); 104 if (!phy->recv_skb) 105 goto err_exit; 106 107 mutex_init(&phy->common.mutex); 108 phy->common.mode = S3FWRN5_MODE_COLD; 109 110 phy->ser_dev = serdev; 111 serdev_device_set_drvdata(serdev, phy); 112 serdev_device_set_client_ops(serdev, &s3fwrn82_serdev_ops); 113 ret = serdev_device_open(serdev); 114 if (ret) { 115 dev_err(&serdev->dev, "Unable to open device\n"); 116 goto err_skb; 117 } 118 119 ret = serdev_device_set_baudrate(serdev, 115200); 120 if (ret != 115200) { 121 ret = -EINVAL; 122 goto err_serdev; 123 } 124 125 serdev_device_set_flow_control(serdev, false); 126 127 phy->common.gpio_en = devm_gpiod_get(&serdev->dev, "en", GPIOD_OUT_HIGH); 128 if (IS_ERR(phy->common.gpio_en)) { 129 ret = PTR_ERR(phy->common.gpio_en); 130 goto err_serdev; 131 } 132 133 phy->common.gpio_fw_wake = devm_gpiod_get(&serdev->dev, "wake", GPIOD_OUT_LOW); 134 if (IS_ERR(phy->common.gpio_fw_wake)) { 135 ret = PTR_ERR(phy->common.gpio_fw_wake); 136 goto err_serdev; 137 } 138 139 ret = s3fwrn5_probe(&phy->common.ndev, phy, &phy->ser_dev->dev, 140 &uart_phy_ops); 141 if (ret < 0) 142 goto err_serdev; 143 144 return ret; 145 146 err_serdev: 147 serdev_device_close(serdev); 148 err_skb: 149 kfree_skb(phy->recv_skb); 150 err_exit: 151 return ret; 152 } 153 154 static void s3fwrn82_uart_remove(struct serdev_device *serdev) 155 { 156 struct s3fwrn82_uart_phy *phy = serdev_device_get_drvdata(serdev); 157 158 s3fwrn5_remove(phy->common.ndev); 159 serdev_device_close(serdev); 160 kfree_skb(phy->recv_skb); 161 } 162 163 static struct serdev_device_driver s3fwrn82_uart_driver = { 164 .probe = s3fwrn82_uart_probe, 165 .remove = s3fwrn82_uart_remove, 166 .driver = { 167 .name = "s3fwrn82_uart", 168 .of_match_table = s3fwrn82_uart_of_match, 169 }, 170 }; 171 172 module_serdev_device_driver(s3fwrn82_uart_driver); 173 174 MODULE_LICENSE("GPL"); 175 MODULE_DESCRIPTION("UART driver for Samsung NFC"); 176 MODULE_AUTHOR("Bongsu Jeon <bongsu.jeon@samsung.com>"); 177