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/clk.h> |
10 | #include <linux/i2c.h> |
11 | #include <linux/gpio.h> |
12 | #include <linux/delay.h> |
13 | #include <linux/of_gpio.h> |
14 | #include <linux/of_irq.h> |
15 | #include <linux/module.h> |
16 | |
17 | #include <net/nfc/nfc.h> |
18 | |
19 | #include "phy_common.h" |
20 | |
21 | #define S3FWRN5_I2C_DRIVER_NAME "s3fwrn5_i2c" |
22 | |
23 | struct s3fwrn5_i2c_phy { |
24 | struct phy_common common; |
25 | struct i2c_client *i2c_dev; |
26 | struct clk *clk; |
27 | |
28 | unsigned int irq_skip:1; |
29 | }; |
30 | |
31 | static void s3fwrn5_i2c_set_mode(void *phy_id, enum s3fwrn5_mode mode) |
32 | { |
33 | struct s3fwrn5_i2c_phy *phy = phy_id; |
34 | |
35 | mutex_lock(&phy->common.mutex); |
36 | |
37 | if (s3fwrn5_phy_power_ctrl(phy: &phy->common, mode) == false) |
38 | goto out; |
39 | |
40 | phy->irq_skip = true; |
41 | |
42 | out: |
43 | mutex_unlock(lock: &phy->common.mutex); |
44 | } |
45 | |
46 | static int s3fwrn5_i2c_write(void *phy_id, struct sk_buff *skb) |
47 | { |
48 | struct s3fwrn5_i2c_phy *phy = phy_id; |
49 | int ret; |
50 | |
51 | mutex_lock(&phy->common.mutex); |
52 | |
53 | phy->irq_skip = false; |
54 | |
55 | ret = i2c_master_send(client: phy->i2c_dev, buf: skb->data, count: skb->len); |
56 | if (ret == -EREMOTEIO) { |
57 | /* Retry, chip was in standby */ |
58 | usleep_range(min: 110000, max: 120000); |
59 | ret = i2c_master_send(client: phy->i2c_dev, buf: skb->data, count: skb->len); |
60 | } |
61 | |
62 | mutex_unlock(lock: &phy->common.mutex); |
63 | |
64 | if (ret < 0) |
65 | return ret; |
66 | |
67 | if (ret != skb->len) |
68 | return -EREMOTEIO; |
69 | |
70 | return 0; |
71 | } |
72 | |
73 | static const struct s3fwrn5_phy_ops i2c_phy_ops = { |
74 | .set_wake = s3fwrn5_phy_set_wake, |
75 | .set_mode = s3fwrn5_i2c_set_mode, |
76 | .get_mode = s3fwrn5_phy_get_mode, |
77 | .write = s3fwrn5_i2c_write, |
78 | }; |
79 | |
80 | static int s3fwrn5_i2c_read(struct s3fwrn5_i2c_phy *phy) |
81 | { |
82 | struct sk_buff *skb; |
83 | size_t hdr_size; |
84 | size_t data_len; |
85 | char hdr[4]; |
86 | int ret; |
87 | |
88 | hdr_size = (phy->common.mode == S3FWRN5_MODE_NCI) ? |
89 | NCI_CTRL_HDR_SIZE : S3FWRN5_FW_HDR_SIZE; |
90 | ret = i2c_master_recv(client: phy->i2c_dev, buf: hdr, count: hdr_size); |
91 | if (ret < 0) |
92 | return ret; |
93 | |
94 | if (ret < hdr_size) |
95 | return -EBADMSG; |
96 | |
97 | data_len = (phy->common.mode == S3FWRN5_MODE_NCI) ? |
98 | ((struct nci_ctrl_hdr *)hdr)->plen : |
99 | ((struct s3fwrn5_fw_header *)hdr)->len; |
100 | |
101 | skb = alloc_skb(size: hdr_size + data_len, GFP_KERNEL); |
102 | if (!skb) |
103 | return -ENOMEM; |
104 | |
105 | skb_put_data(skb, data: hdr, len: hdr_size); |
106 | |
107 | if (data_len == 0) |
108 | goto out; |
109 | |
110 | ret = i2c_master_recv(client: phy->i2c_dev, buf: skb_put(skb, len: data_len), count: data_len); |
111 | if (ret != data_len) { |
112 | kfree_skb(skb); |
113 | return -EBADMSG; |
114 | } |
115 | |
116 | out: |
117 | return s3fwrn5_recv_frame(ndev: phy->common.ndev, skb, mode: phy->common.mode); |
118 | } |
119 | |
120 | static irqreturn_t s3fwrn5_i2c_irq_thread_fn(int irq, void *phy_id) |
121 | { |
122 | struct s3fwrn5_i2c_phy *phy = phy_id; |
123 | |
124 | if (!phy || !phy->common.ndev) { |
125 | WARN_ON_ONCE(1); |
126 | return IRQ_NONE; |
127 | } |
128 | |
129 | mutex_lock(&phy->common.mutex); |
130 | |
131 | if (phy->irq_skip) |
132 | goto out; |
133 | |
134 | switch (phy->common.mode) { |
135 | case S3FWRN5_MODE_NCI: |
136 | case S3FWRN5_MODE_FW: |
137 | s3fwrn5_i2c_read(phy); |
138 | break; |
139 | case S3FWRN5_MODE_COLD: |
140 | break; |
141 | } |
142 | |
143 | out: |
144 | mutex_unlock(lock: &phy->common.mutex); |
145 | |
146 | return IRQ_HANDLED; |
147 | } |
148 | |
149 | static int s3fwrn5_i2c_parse_dt(struct i2c_client *client) |
150 | { |
151 | struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client); |
152 | struct device_node *np = client->dev.of_node; |
153 | |
154 | if (!np) |
155 | return -ENODEV; |
156 | |
157 | phy->common.gpio_en = of_get_named_gpio(np, list_name: "en-gpios" , index: 0); |
158 | if (!gpio_is_valid(number: phy->common.gpio_en)) { |
159 | /* Support also deprecated property */ |
160 | phy->common.gpio_en = of_get_named_gpio(np, |
161 | list_name: "s3fwrn5,en-gpios" , |
162 | index: 0); |
163 | if (!gpio_is_valid(number: phy->common.gpio_en)) |
164 | return -ENODEV; |
165 | } |
166 | |
167 | phy->common.gpio_fw_wake = of_get_named_gpio(np, list_name: "wake-gpios" , index: 0); |
168 | if (!gpio_is_valid(number: phy->common.gpio_fw_wake)) { |
169 | /* Support also deprecated property */ |
170 | phy->common.gpio_fw_wake = of_get_named_gpio(np, |
171 | list_name: "s3fwrn5,fw-gpios" , |
172 | index: 0); |
173 | if (!gpio_is_valid(number: phy->common.gpio_fw_wake)) |
174 | return -ENODEV; |
175 | } |
176 | |
177 | return 0; |
178 | } |
179 | |
180 | static int s3fwrn5_i2c_probe(struct i2c_client *client) |
181 | { |
182 | struct s3fwrn5_i2c_phy *phy; |
183 | int ret; |
184 | |
185 | phy = devm_kzalloc(dev: &client->dev, size: sizeof(*phy), GFP_KERNEL); |
186 | if (!phy) |
187 | return -ENOMEM; |
188 | |
189 | mutex_init(&phy->common.mutex); |
190 | phy->common.mode = S3FWRN5_MODE_COLD; |
191 | phy->irq_skip = true; |
192 | |
193 | phy->i2c_dev = client; |
194 | i2c_set_clientdata(client, data: phy); |
195 | |
196 | ret = s3fwrn5_i2c_parse_dt(client); |
197 | if (ret < 0) |
198 | return ret; |
199 | |
200 | ret = devm_gpio_request_one(dev: &phy->i2c_dev->dev, gpio: phy->common.gpio_en, |
201 | GPIOF_OUT_INIT_HIGH, label: "s3fwrn5_en" ); |
202 | if (ret < 0) |
203 | return ret; |
204 | |
205 | ret = devm_gpio_request_one(dev: &phy->i2c_dev->dev, |
206 | gpio: phy->common.gpio_fw_wake, |
207 | GPIOF_OUT_INIT_LOW, label: "s3fwrn5_fw_wake" ); |
208 | if (ret < 0) |
209 | return ret; |
210 | |
211 | /* |
212 | * S3FWRN5 depends on a clock input ("XI" pin) to function properly. |
213 | * Depending on the hardware configuration this could be an always-on |
214 | * oscillator or some external clock that must be explicitly enabled. |
215 | * Make sure the clock is running before starting S3FWRN5. |
216 | */ |
217 | phy->clk = devm_clk_get_optional_enabled(dev: &client->dev, NULL); |
218 | if (IS_ERR(ptr: phy->clk)) |
219 | return dev_err_probe(dev: &client->dev, err: PTR_ERR(ptr: phy->clk), |
220 | fmt: "failed to get clock\n" ); |
221 | |
222 | ret = s3fwrn5_probe(ndev: &phy->common.ndev, phy_id: phy, pdev: &phy->i2c_dev->dev, |
223 | phy_ops: &i2c_phy_ops); |
224 | if (ret < 0) |
225 | return ret; |
226 | |
227 | ret = devm_request_threaded_irq(dev: &client->dev, irq: phy->i2c_dev->irq, NULL, |
228 | thread_fn: s3fwrn5_i2c_irq_thread_fn, IRQF_ONESHOT, |
229 | S3FWRN5_I2C_DRIVER_NAME, dev_id: phy); |
230 | if (ret) |
231 | goto s3fwrn5_remove; |
232 | |
233 | return 0; |
234 | |
235 | s3fwrn5_remove: |
236 | s3fwrn5_remove(ndev: phy->common.ndev); |
237 | return ret; |
238 | } |
239 | |
240 | static void s3fwrn5_i2c_remove(struct i2c_client *client) |
241 | { |
242 | struct s3fwrn5_i2c_phy *phy = i2c_get_clientdata(client); |
243 | |
244 | s3fwrn5_remove(ndev: phy->common.ndev); |
245 | } |
246 | |
247 | static const struct i2c_device_id s3fwrn5_i2c_id_table[] = { |
248 | {S3FWRN5_I2C_DRIVER_NAME, 0}, |
249 | {} |
250 | }; |
251 | MODULE_DEVICE_TABLE(i2c, s3fwrn5_i2c_id_table); |
252 | |
253 | static const struct of_device_id of_s3fwrn5_i2c_match[] __maybe_unused = { |
254 | { .compatible = "samsung,s3fwrn5-i2c" , }, |
255 | {} |
256 | }; |
257 | MODULE_DEVICE_TABLE(of, of_s3fwrn5_i2c_match); |
258 | |
259 | static struct i2c_driver s3fwrn5_i2c_driver = { |
260 | .driver = { |
261 | .name = S3FWRN5_I2C_DRIVER_NAME, |
262 | .of_match_table = of_match_ptr(of_s3fwrn5_i2c_match), |
263 | }, |
264 | .probe = s3fwrn5_i2c_probe, |
265 | .remove = s3fwrn5_i2c_remove, |
266 | .id_table = s3fwrn5_i2c_id_table, |
267 | }; |
268 | |
269 | module_i2c_driver(s3fwrn5_i2c_driver); |
270 | |
271 | MODULE_LICENSE("GPL" ); |
272 | MODULE_DESCRIPTION("I2C driver for Samsung S3FWRN5" ); |
273 | MODULE_AUTHOR("Robert Baldyga <r.baldyga@samsung.com>" ); |
274 | |