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a10e763b | 1 | // SPDX-License-Identifier: GPL-2.0-only |
db23e500 LP |
2 | /* |
3 | * Driver for the Diolan DLN-2 USB-I2C adapter | |
4 | * | |
5 | * Copyright (c) 2014 Intel Corporation | |
6 | * | |
7 | * Derived from: | |
8 | * i2c-diolan-u2c.c | |
9 | * Copyright (c) 2010-2011 Ericsson AB | |
db23e500 LP |
10 | */ |
11 | ||
12 | #include <linux/kernel.h> | |
13 | #include <linux/module.h> | |
14 | #include <linux/types.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/i2c.h> | |
17 | #include <linux/platform_device.h> | |
18 | #include <linux/mfd/dln2.h> | |
afc34be0 | 19 | #include <linux/acpi.h> |
db23e500 LP |
20 | |
21 | #define DLN2_I2C_MODULE_ID 0x03 | |
22 | #define DLN2_I2C_CMD(cmd) DLN2_CMD(cmd, DLN2_I2C_MODULE_ID) | |
23 | ||
24 | /* I2C commands */ | |
25 | #define DLN2_I2C_GET_PORT_COUNT DLN2_I2C_CMD(0x00) | |
26 | #define DLN2_I2C_ENABLE DLN2_I2C_CMD(0x01) | |
27 | #define DLN2_I2C_DISABLE DLN2_I2C_CMD(0x02) | |
28 | #define DLN2_I2C_IS_ENABLED DLN2_I2C_CMD(0x03) | |
29 | #define DLN2_I2C_WRITE DLN2_I2C_CMD(0x06) | |
30 | #define DLN2_I2C_READ DLN2_I2C_CMD(0x07) | |
31 | #define DLN2_I2C_SCAN_DEVICES DLN2_I2C_CMD(0x08) | |
32 | #define DLN2_I2C_PULLUP_ENABLE DLN2_I2C_CMD(0x09) | |
33 | #define DLN2_I2C_PULLUP_DISABLE DLN2_I2C_CMD(0x0A) | |
34 | #define DLN2_I2C_PULLUP_IS_ENABLED DLN2_I2C_CMD(0x0B) | |
35 | #define DLN2_I2C_TRANSFER DLN2_I2C_CMD(0x0C) | |
36 | #define DLN2_I2C_SET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0D) | |
37 | #define DLN2_I2C_GET_MAX_REPLY_COUNT DLN2_I2C_CMD(0x0E) | |
38 | ||
39 | #define DLN2_I2C_MAX_XFER_SIZE 256 | |
40 | #define DLN2_I2C_BUF_SIZE (DLN2_I2C_MAX_XFER_SIZE + 16) | |
41 | ||
42 | struct dln2_i2c { | |
43 | struct platform_device *pdev; | |
44 | struct i2c_adapter adapter; | |
45 | u8 port; | |
46 | /* | |
47 | * Buffer to hold the packet for read or write transfers. One is enough | |
48 | * since we can't have multiple transfers in parallel on the i2c bus. | |
49 | */ | |
50 | void *buf; | |
51 | }; | |
52 | ||
53 | static int dln2_i2c_enable(struct dln2_i2c *dln2, bool enable) | |
54 | { | |
db23e500 LP |
55 | u16 cmd; |
56 | struct { | |
57 | u8 port; | |
58 | } tx; | |
59 | ||
60 | tx.port = dln2->port; | |
61 | ||
62 | if (enable) | |
63 | cmd = DLN2_I2C_ENABLE; | |
64 | else | |
65 | cmd = DLN2_I2C_DISABLE; | |
66 | ||
93316428 | 67 | return dln2_transfer_tx(dln2->pdev, cmd, &tx, sizeof(tx)); |
db23e500 LP |
68 | } |
69 | ||
70 | static int dln2_i2c_write(struct dln2_i2c *dln2, u8 addr, | |
71 | u8 *data, u16 data_len) | |
72 | { | |
73 | int ret; | |
74 | struct { | |
75 | u8 port; | |
76 | u8 addr; | |
77 | u8 mem_addr_len; | |
78 | __le32 mem_addr; | |
79 | __le16 buf_len; | |
80 | u8 buf[DLN2_I2C_MAX_XFER_SIZE]; | |
81 | } __packed *tx = dln2->buf; | |
82 | unsigned len; | |
83 | ||
84 | BUILD_BUG_ON(sizeof(*tx) > DLN2_I2C_BUF_SIZE); | |
85 | ||
86 | tx->port = dln2->port; | |
87 | tx->addr = addr; | |
88 | tx->mem_addr_len = 0; | |
89 | tx->mem_addr = 0; | |
90 | tx->buf_len = cpu_to_le16(data_len); | |
91 | memcpy(tx->buf, data, data_len); | |
92 | ||
93 | len = sizeof(*tx) + data_len - DLN2_I2C_MAX_XFER_SIZE; | |
94 | ret = dln2_transfer_tx(dln2->pdev, DLN2_I2C_WRITE, tx, len); | |
95 | if (ret < 0) | |
96 | return ret; | |
97 | ||
98 | return data_len; | |
99 | } | |
100 | ||
101 | static int dln2_i2c_read(struct dln2_i2c *dln2, u16 addr, u8 *data, | |
102 | u16 data_len) | |
103 | { | |
104 | int ret; | |
105 | struct { | |
106 | u8 port; | |
107 | u8 addr; | |
108 | u8 mem_addr_len; | |
109 | __le32 mem_addr; | |
110 | __le16 buf_len; | |
111 | } __packed tx; | |
112 | struct { | |
113 | __le16 buf_len; | |
114 | u8 buf[DLN2_I2C_MAX_XFER_SIZE]; | |
115 | } __packed *rx = dln2->buf; | |
116 | unsigned rx_len = sizeof(*rx); | |
117 | ||
118 | BUILD_BUG_ON(sizeof(*rx) > DLN2_I2C_BUF_SIZE); | |
119 | ||
120 | tx.port = dln2->port; | |
121 | tx.addr = addr; | |
122 | tx.mem_addr_len = 0; | |
123 | tx.mem_addr = 0; | |
124 | tx.buf_len = cpu_to_le16(data_len); | |
125 | ||
126 | ret = dln2_transfer(dln2->pdev, DLN2_I2C_READ, &tx, sizeof(tx), | |
127 | rx, &rx_len); | |
128 | if (ret < 0) | |
129 | return ret; | |
130 | if (rx_len < sizeof(rx->buf_len) + data_len) | |
131 | return -EPROTO; | |
132 | if (le16_to_cpu(rx->buf_len) != data_len) | |
133 | return -EPROTO; | |
134 | ||
135 | memcpy(data, rx->buf, data_len); | |
136 | ||
137 | return data_len; | |
138 | } | |
139 | ||
140 | static int dln2_i2c_xfer(struct i2c_adapter *adapter, | |
141 | struct i2c_msg *msgs, int num) | |
142 | { | |
143 | struct dln2_i2c *dln2 = i2c_get_adapdata(adapter); | |
144 | struct i2c_msg *pmsg; | |
db23e500 LP |
145 | int i; |
146 | ||
147 | for (i = 0; i < num; i++) { | |
148 | int ret; | |
149 | ||
150 | pmsg = &msgs[i]; | |
151 | ||
db23e500 LP |
152 | if (pmsg->flags & I2C_M_RD) { |
153 | ret = dln2_i2c_read(dln2, pmsg->addr, pmsg->buf, | |
154 | pmsg->len); | |
155 | if (ret < 0) | |
156 | return ret; | |
157 | ||
158 | pmsg->len = ret; | |
159 | } else { | |
160 | ret = dln2_i2c_write(dln2, pmsg->addr, pmsg->buf, | |
161 | pmsg->len); | |
162 | if (ret != pmsg->len) | |
163 | return -EPROTO; | |
164 | } | |
165 | } | |
166 | ||
167 | return num; | |
168 | } | |
169 | ||
170 | static u32 dln2_i2c_func(struct i2c_adapter *a) | |
171 | { | |
172 | return I2C_FUNC_I2C | I2C_FUNC_SMBUS_BYTE | I2C_FUNC_SMBUS_BYTE_DATA | | |
173 | I2C_FUNC_SMBUS_WORD_DATA | I2C_FUNC_SMBUS_BLOCK_PROC_CALL | | |
174 | I2C_FUNC_SMBUS_I2C_BLOCK; | |
175 | } | |
176 | ||
177 | static const struct i2c_algorithm dln2_i2c_usb_algorithm = { | |
178 | .master_xfer = dln2_i2c_xfer, | |
179 | .functionality = dln2_i2c_func, | |
180 | }; | |
181 | ||
379883cc | 182 | static const struct i2c_adapter_quirks dln2_i2c_quirks = { |
afe90203 WS |
183 | .max_read_len = DLN2_I2C_MAX_XFER_SIZE, |
184 | .max_write_len = DLN2_I2C_MAX_XFER_SIZE, | |
185 | }; | |
186 | ||
db23e500 LP |
187 | static int dln2_i2c_probe(struct platform_device *pdev) |
188 | { | |
189 | int ret; | |
190 | struct dln2_i2c *dln2; | |
191 | struct device *dev = &pdev->dev; | |
192 | struct dln2_platform_data *pdata = dev_get_platdata(&pdev->dev); | |
193 | ||
194 | dln2 = devm_kzalloc(dev, sizeof(*dln2), GFP_KERNEL); | |
195 | if (!dln2) | |
196 | return -ENOMEM; | |
197 | ||
198 | dln2->buf = devm_kmalloc(dev, DLN2_I2C_BUF_SIZE, GFP_KERNEL); | |
199 | if (!dln2->buf) | |
200 | return -ENOMEM; | |
201 | ||
202 | dln2->pdev = pdev; | |
203 | dln2->port = pdata->port; | |
204 | ||
205 | /* setup i2c adapter description */ | |
206 | dln2->adapter.owner = THIS_MODULE; | |
207 | dln2->adapter.class = I2C_CLASS_HWMON; | |
208 | dln2->adapter.algo = &dln2_i2c_usb_algorithm; | |
afe90203 | 209 | dln2->adapter.quirks = &dln2_i2c_quirks; |
db23e500 | 210 | dln2->adapter.dev.parent = dev; |
afc34be0 | 211 | ACPI_COMPANION_SET(&dln2->adapter.dev, ACPI_COMPANION(&pdev->dev)); |
3b10db23 | 212 | dln2->adapter.dev.of_node = dev->of_node; |
db23e500 LP |
213 | i2c_set_adapdata(&dln2->adapter, dln2); |
214 | snprintf(dln2->adapter.name, sizeof(dln2->adapter.name), "%s-%s-%d", | |
215 | "dln2-i2c", dev_name(pdev->dev.parent), dln2->port); | |
216 | ||
217 | platform_set_drvdata(pdev, dln2); | |
218 | ||
219 | /* initialize the i2c interface */ | |
220 | ret = dln2_i2c_enable(dln2, true); | |
235712aa LC |
221 | if (ret < 0) |
222 | return dev_err_probe(dev, ret, "failed to initialize adapter\n"); | |
db23e500 LP |
223 | |
224 | /* and finally attach to i2c layer */ | |
225 | ret = i2c_add_adapter(&dln2->adapter); | |
ea734404 | 226 | if (ret < 0) |
db23e500 | 227 | goto out_disable; |
db23e500 LP |
228 | |
229 | return 0; | |
230 | ||
231 | out_disable: | |
232 | dln2_i2c_enable(dln2, false); | |
233 | ||
234 | return ret; | |
235 | } | |
236 | ||
e190a0c3 | 237 | static void dln2_i2c_remove(struct platform_device *pdev) |
db23e500 LP |
238 | { |
239 | struct dln2_i2c *dln2 = platform_get_drvdata(pdev); | |
240 | ||
241 | i2c_del_adapter(&dln2->adapter); | |
242 | dln2_i2c_enable(dln2, false); | |
db23e500 LP |
243 | } |
244 | ||
245 | static struct platform_driver dln2_i2c_driver = { | |
246 | .driver.name = "dln2-i2c", | |
247 | .probe = dln2_i2c_probe, | |
e190a0c3 | 248 | .remove_new = dln2_i2c_remove, |
db23e500 LP |
249 | }; |
250 | ||
251 | module_platform_driver(dln2_i2c_driver); | |
252 | ||
253 | MODULE_AUTHOR("Laurentiu Palcu <laurentiu.palcu@intel.com>"); | |
254 | MODULE_DESCRIPTION("Driver for the Diolan DLN2 I2C master interface"); | |
255 | MODULE_LICENSE("GPL v2"); | |
256 | MODULE_ALIAS("platform:dln2-i2c"); |