1/*
2 * Copyright 2007-8 Advanced Micro Devices, Inc.
3 * Copyright 2008 Red Hat Inc.
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
18 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
19 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
20 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
21 * OTHER DEALINGS IN THE SOFTWARE.
22 *
23 * Authors: Dave Airlie
24 * Alex Deucher
25 */
26
27#include <linux/pci.h>
28
29#include <drm/drm_edid.h>
30#include <drm/amdgpu_drm.h>
31#include "amdgpu.h"
32#include "amdgpu_i2c.h"
33#include "amdgpu_atombios.h"
34#include "atom.h"
35#include "atombios_dp.h"
36#include "atombios_i2c.h"
37
38/* bit banging i2c */
39static int amdgpu_i2c_pre_xfer(struct i2c_adapter *i2c_adap)
40{
41 struct amdgpu_i2c_chan *i2c = i2c_get_adapdata(adap: i2c_adap);
42 struct amdgpu_device *adev = drm_to_adev(ddev: i2c->dev);
43 struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
44 uint32_t temp;
45
46 mutex_lock(&i2c->mutex);
47
48 /* switch the pads to ddc mode */
49 if (rec->hw_capable) {
50 temp = RREG32(rec->mask_clk_reg);
51 temp &= ~(1 << 16);
52 WREG32(rec->mask_clk_reg, temp);
53 }
54
55 /* clear the output pin values */
56 temp = RREG32(rec->a_clk_reg) & ~rec->a_clk_mask;
57 WREG32(rec->a_clk_reg, temp);
58
59 temp = RREG32(rec->a_data_reg) & ~rec->a_data_mask;
60 WREG32(rec->a_data_reg, temp);
61
62 /* set the pins to input */
63 temp = RREG32(rec->en_clk_reg) & ~rec->en_clk_mask;
64 WREG32(rec->en_clk_reg, temp);
65
66 temp = RREG32(rec->en_data_reg) & ~rec->en_data_mask;
67 WREG32(rec->en_data_reg, temp);
68
69 /* mask the gpio pins for software use */
70 temp = RREG32(rec->mask_clk_reg) | rec->mask_clk_mask;
71 WREG32(rec->mask_clk_reg, temp);
72 temp = RREG32(rec->mask_clk_reg);
73
74 temp = RREG32(rec->mask_data_reg) | rec->mask_data_mask;
75 WREG32(rec->mask_data_reg, temp);
76 temp = RREG32(rec->mask_data_reg);
77
78 return 0;
79}
80
81static void amdgpu_i2c_post_xfer(struct i2c_adapter *i2c_adap)
82{
83 struct amdgpu_i2c_chan *i2c = i2c_get_adapdata(adap: i2c_adap);
84 struct amdgpu_device *adev = drm_to_adev(ddev: i2c->dev);
85 struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
86 uint32_t temp;
87
88 /* unmask the gpio pins for software use */
89 temp = RREG32(rec->mask_clk_reg) & ~rec->mask_clk_mask;
90 WREG32(rec->mask_clk_reg, temp);
91 temp = RREG32(rec->mask_clk_reg);
92
93 temp = RREG32(rec->mask_data_reg) & ~rec->mask_data_mask;
94 WREG32(rec->mask_data_reg, temp);
95 temp = RREG32(rec->mask_data_reg);
96
97 mutex_unlock(lock: &i2c->mutex);
98}
99
100static int amdgpu_i2c_get_clock(void *i2c_priv)
101{
102 struct amdgpu_i2c_chan *i2c = i2c_priv;
103 struct amdgpu_device *adev = drm_to_adev(ddev: i2c->dev);
104 struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
105 uint32_t val;
106
107 /* read the value off the pin */
108 val = RREG32(rec->y_clk_reg);
109 val &= rec->y_clk_mask;
110
111 return (val != 0);
112}
113
114
115static int amdgpu_i2c_get_data(void *i2c_priv)
116{
117 struct amdgpu_i2c_chan *i2c = i2c_priv;
118 struct amdgpu_device *adev = drm_to_adev(ddev: i2c->dev);
119 struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
120 uint32_t val;
121
122 /* read the value off the pin */
123 val = RREG32(rec->y_data_reg);
124 val &= rec->y_data_mask;
125
126 return (val != 0);
127}
128
129static void amdgpu_i2c_set_clock(void *i2c_priv, int clock)
130{
131 struct amdgpu_i2c_chan *i2c = i2c_priv;
132 struct amdgpu_device *adev = drm_to_adev(ddev: i2c->dev);
133 struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
134 uint32_t val;
135
136 /* set pin direction */
137 val = RREG32(rec->en_clk_reg) & ~rec->en_clk_mask;
138 val |= clock ? 0 : rec->en_clk_mask;
139 WREG32(rec->en_clk_reg, val);
140}
141
142static void amdgpu_i2c_set_data(void *i2c_priv, int data)
143{
144 struct amdgpu_i2c_chan *i2c = i2c_priv;
145 struct amdgpu_device *adev = drm_to_adev(ddev: i2c->dev);
146 struct amdgpu_i2c_bus_rec *rec = &i2c->rec;
147 uint32_t val;
148
149 /* set pin direction */
150 val = RREG32(rec->en_data_reg) & ~rec->en_data_mask;
151 val |= data ? 0 : rec->en_data_mask;
152 WREG32(rec->en_data_reg, val);
153}
154
155static const struct i2c_algorithm amdgpu_atombios_i2c_algo = {
156 .master_xfer = amdgpu_atombios_i2c_xfer,
157 .functionality = amdgpu_atombios_i2c_func,
158};
159
160struct amdgpu_i2c_chan *amdgpu_i2c_create(struct drm_device *dev,
161 const struct amdgpu_i2c_bus_rec *rec,
162 const char *name)
163{
164 struct amdgpu_i2c_chan *i2c;
165 int ret;
166
167 /* don't add the mm_i2c bus unless hw_i2c is enabled */
168 if (rec->mm_i2c && (amdgpu_hw_i2c == 0))
169 return NULL;
170
171 i2c = kzalloc(sizeof(struct amdgpu_i2c_chan), GFP_KERNEL);
172 if (i2c == NULL)
173 return NULL;
174
175 i2c->rec = *rec;
176 i2c->adapter.owner = THIS_MODULE;
177 i2c->adapter.dev.parent = dev->dev;
178 i2c->dev = dev;
179 i2c_set_adapdata(adap: &i2c->adapter, data: i2c);
180 mutex_init(&i2c->mutex);
181 if (rec->hw_capable &&
182 amdgpu_hw_i2c) {
183 /* hw i2c using atom */
184 snprintf(buf: i2c->adapter.name, size: sizeof(i2c->adapter.name),
185 fmt: "AMDGPU i2c hw bus %s", name);
186 i2c->adapter.algo = &amdgpu_atombios_i2c_algo;
187 ret = devm_i2c_add_adapter(dev: dev->dev, adapter: &i2c->adapter);
188 if (ret)
189 goto out_free;
190 } else {
191 /* set the amdgpu bit adapter */
192 snprintf(buf: i2c->adapter.name, size: sizeof(i2c->adapter.name),
193 fmt: "AMDGPU i2c bit bus %s", name);
194 i2c->adapter.algo_data = &i2c->bit;
195 i2c->bit.pre_xfer = amdgpu_i2c_pre_xfer;
196 i2c->bit.post_xfer = amdgpu_i2c_post_xfer;
197 i2c->bit.setsda = amdgpu_i2c_set_data;
198 i2c->bit.setscl = amdgpu_i2c_set_clock;
199 i2c->bit.getsda = amdgpu_i2c_get_data;
200 i2c->bit.getscl = amdgpu_i2c_get_clock;
201 i2c->bit.udelay = 10;
202 i2c->bit.timeout = usecs_to_jiffies(u: 2200); /* from VESA */
203 i2c->bit.data = i2c;
204 ret = i2c_bit_add_bus(&i2c->adapter);
205 if (ret) {
206 DRM_ERROR("Failed to register bit i2c %s\n", name);
207 goto out_free;
208 }
209 }
210
211 return i2c;
212out_free:
213 kfree(objp: i2c);
214 return NULL;
215
216}
217
218void amdgpu_i2c_init(struct amdgpu_device *adev)
219{
220 if (!adev->is_atom_fw) {
221 if (!amdgpu_device_has_dc_support(adev)) {
222 amdgpu_atombios_i2c_init(adev);
223 } else {
224 switch (adev->asic_type) {
225 case CHIP_POLARIS10:
226 case CHIP_POLARIS11:
227 case CHIP_POLARIS12:
228 amdgpu_atombios_oem_i2c_init(adev, i2c_id: 0x97);
229 break;
230 default:
231 break;
232 }
233 }
234 }
235}
236
237/* remove all the buses */
238void amdgpu_i2c_fini(struct amdgpu_device *adev)
239{
240 int i;
241
242 for (i = 0; i < AMDGPU_MAX_I2C_BUS; i++)
243 if (adev->i2c_bus[i])
244 adev->i2c_bus[i] = NULL;
245}
246
247/* looks up bus based on id */
248struct amdgpu_i2c_chan *
249amdgpu_i2c_lookup(struct amdgpu_device *adev,
250 const struct amdgpu_i2c_bus_rec *i2c_bus)
251{
252 int i;
253
254 for (i = 0; i < AMDGPU_MAX_I2C_BUS; i++) {
255 if (adev->i2c_bus[i] &&
256 (adev->i2c_bus[i]->rec.i2c_id == i2c_bus->i2c_id)) {
257 return adev->i2c_bus[i];
258 }
259 }
260 return NULL;
261}
262
263static int amdgpu_i2c_get_byte(struct amdgpu_i2c_chan *i2c_bus,
264 u8 slave_addr,
265 u8 addr,
266 u8 *val)
267{
268 u8 out_buf[2];
269 u8 in_buf[2];
270 struct i2c_msg msgs[] = {
271 {
272 .addr = slave_addr,
273 .flags = 0,
274 .len = 1,
275 .buf = out_buf,
276 },
277 {
278 .addr = slave_addr,
279 .flags = I2C_M_RD,
280 .len = 1,
281 .buf = in_buf,
282 }
283 };
284
285 out_buf[0] = addr;
286 out_buf[1] = 0;
287
288 if (i2c_transfer(adap: &i2c_bus->adapter, msgs, num: 2) != 2) {
289 DRM_DEBUG("i2c 0x%02x read failed\n", addr);
290 return -EIO;
291 }
292
293 *val = in_buf[0];
294 DRM_DEBUG("val = 0x%02x\n", *val);
295
296 return 0;
297}
298
299static int amdgpu_i2c_put_byte(struct amdgpu_i2c_chan *i2c_bus,
300 u8 slave_addr,
301 u8 addr,
302 u8 val)
303{
304 uint8_t out_buf[2];
305 struct i2c_msg msg = {
306 .addr = slave_addr,
307 .flags = 0,
308 .len = 2,
309 .buf = out_buf,
310 };
311
312 out_buf[0] = addr;
313 out_buf[1] = val;
314
315 if (i2c_transfer(adap: &i2c_bus->adapter, msgs: &msg, num: 1) != 1) {
316 DRM_DEBUG("i2c 0x%02x 0x%02x write failed\n", addr, val);
317 return -EIO;
318 }
319
320 return 0;
321}
322
323/* ddc router switching */
324void
325amdgpu_i2c_router_select_ddc_port(const struct amdgpu_connector *amdgpu_connector)
326{
327 u8 val = 0;
328
329 if (!amdgpu_connector->router.ddc_valid)
330 return;
331
332 if (!amdgpu_connector->router_bus)
333 return;
334
335 if (amdgpu_i2c_get_byte(i2c_bus: amdgpu_connector->router_bus,
336 slave_addr: amdgpu_connector->router.i2c_addr,
337 addr: 0x3, val: &val))
338 return;
339 val &= ~amdgpu_connector->router.ddc_mux_control_pin;
340 amdgpu_i2c_put_byte(i2c_bus: amdgpu_connector->router_bus,
341 slave_addr: amdgpu_connector->router.i2c_addr,
342 addr: 0x3, val);
343 if (amdgpu_i2c_get_byte(i2c_bus: amdgpu_connector->router_bus,
344 slave_addr: amdgpu_connector->router.i2c_addr,
345 addr: 0x1, val: &val))
346 return;
347 val &= ~amdgpu_connector->router.ddc_mux_control_pin;
348 val |= amdgpu_connector->router.ddc_mux_state;
349 amdgpu_i2c_put_byte(i2c_bus: amdgpu_connector->router_bus,
350 slave_addr: amdgpu_connector->router.i2c_addr,
351 addr: 0x1, val);
352}
353
354/* clock/data router switching */
355void
356amdgpu_i2c_router_select_cd_port(const struct amdgpu_connector *amdgpu_connector)
357{
358 u8 val;
359
360 if (!amdgpu_connector->router.cd_valid)
361 return;
362
363 if (!amdgpu_connector->router_bus)
364 return;
365
366 if (amdgpu_i2c_get_byte(i2c_bus: amdgpu_connector->router_bus,
367 slave_addr: amdgpu_connector->router.i2c_addr,
368 addr: 0x3, val: &val))
369 return;
370 val &= ~amdgpu_connector->router.cd_mux_control_pin;
371 amdgpu_i2c_put_byte(i2c_bus: amdgpu_connector->router_bus,
372 slave_addr: amdgpu_connector->router.i2c_addr,
373 addr: 0x3, val);
374 if (amdgpu_i2c_get_byte(i2c_bus: amdgpu_connector->router_bus,
375 slave_addr: amdgpu_connector->router.i2c_addr,
376 addr: 0x1, val: &val))
377 return;
378 val &= ~amdgpu_connector->router.cd_mux_control_pin;
379 val |= amdgpu_connector->router.cd_mux_state;
380 amdgpu_i2c_put_byte(i2c_bus: amdgpu_connector->router_bus,
381 slave_addr: amdgpu_connector->router.i2c_addr,
382 addr: 0x1, val);
383}
384

source code of linux/drivers/gpu/drm/amd/amdgpu/amdgpu_i2c.c