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1/*
2 * HDMI CEC
3 *
4 * Based on the CEC code from hdmi_ti_4xxx_ip.c from Android.
5 *
6 * Copyright (C) 2010-2011 Texas Instruments Incorporated - https://www.ti.com/
7 * Authors: Yong Zhi
8 * Mythri pk <mythripk@ti.com>
9 *
10 * Heavily modified to use the linux CEC framework:
11 *
12 * Copyright 2016-2017 Cisco Systems, Inc. and/or its affiliates. All rights reserved.
13 *
14 * This program is free software; you may redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; version 2 of the License.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
19 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
20 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
21 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
22 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
23 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
24 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
25 * SOFTWARE.
26 */
27
28#include <linux/kernel.h>
29#include <linux/err.h>
30#include <linux/io.h>
31#include <linux/platform_device.h>
32#include <linux/slab.h>
33
34#include "dss.h"
35#include "hdmi.h"
36#include "hdmi4_core.h"
37#include "hdmi4_cec.h"
38
39/* HDMI CEC */
40#define HDMI_CEC_DEV_ID 0x900
41#define HDMI_CEC_SPEC 0x904
42
43/* Not really a debug register, more a low-level control register */
44#define HDMI_CEC_DBG_3 0x91C
45#define HDMI_CEC_TX_INIT 0x920
46#define HDMI_CEC_TX_DEST 0x924
47#define HDMI_CEC_SETUP 0x938
48#define HDMI_CEC_TX_COMMAND 0x93C
49#define HDMI_CEC_TX_OPERAND 0x940
50#define HDMI_CEC_TRANSMIT_DATA 0x97C
51#define HDMI_CEC_CA_7_0 0x988
52#define HDMI_CEC_CA_15_8 0x98C
53#define HDMI_CEC_INT_STATUS_0 0x998
54#define HDMI_CEC_INT_STATUS_1 0x99C
55#define HDMI_CEC_INT_ENABLE_0 0x990
56#define HDMI_CEC_INT_ENABLE_1 0x994
57#define HDMI_CEC_RX_CONTROL 0x9B0
58#define HDMI_CEC_RX_COUNT 0x9B4
59#define HDMI_CEC_RX_CMD_HEADER 0x9B8
60#define HDMI_CEC_RX_COMMAND 0x9BC
61#define HDMI_CEC_RX_OPERAND 0x9C0
62
63#define HDMI_CEC_TX_FIFO_INT_MASK 0x64
64#define HDMI_CEC_RETRANSMIT_CNT_INT_MASK 0x2
65
66#define HDMI_CORE_CEC_RETRY 200
67
68static void hdmi_cec_received_msg(struct hdmi_core_data *core)
69{
70 u32 cnt = hdmi_read_reg(core->base, HDMI_CEC_RX_COUNT) & 0xff;
71
72 /* While there are CEC frames in the FIFO */
73 while (cnt & 0x70) {
74 /* and the frame doesn't have an error */
75 if (!(cnt & 0x80)) {
76 struct cec_msg msg = {};
77 unsigned int i;
78
79 /* then read the message */
80 msg.len = cnt & 0xf;
81 if (msg.len > CEC_MAX_MSG_SIZE - 2)
82 msg.len = CEC_MAX_MSG_SIZE - 2;
83 msg.msg[0] = hdmi_read_reg(core->base,
84 HDMI_CEC_RX_CMD_HEADER);
85 msg.msg[1] = hdmi_read_reg(core->base,
86 HDMI_CEC_RX_COMMAND);
87 for (i = 0; i < msg.len; i++) {
88 unsigned int reg = HDMI_CEC_RX_OPERAND + i * 4;
89
90 msg.msg[2 + i] =
91 hdmi_read_reg(core->base, reg);
92 }
93 msg.len += 2;
94 cec_received_msg(core->adap, &msg);
95 }
96 /* Clear the current frame from the FIFO */
97 hdmi_write_reg(core->base, HDMI_CEC_RX_CONTROL, 1);
98 /* Wait until the current frame is cleared */
99 while (hdmi_read_reg(core->base, HDMI_CEC_RX_CONTROL) & 1)
100 udelay(1);
101 /*
102 * Re-read the count register and loop to see if there are
103 * more messages in the FIFO.
104 */
105 cnt = hdmi_read_reg(core->base, HDMI_CEC_RX_COUNT) & 0xff;
106 }
107}
108
109void hdmi4_cec_irq(struct hdmi_core_data *core)
110{
111 u32 stat0 = hdmi_read_reg(core->base, HDMI_CEC_INT_STATUS_0);
112 u32 stat1 = hdmi_read_reg(core->base, HDMI_CEC_INT_STATUS_1);
113
114 hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_0, stat0);
115 hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_1, stat1);
116
117 if (stat0 & 0x20) {
118 cec_transmit_done(core->adap, CEC_TX_STATUS_OK,
119 0, 0, 0, 0);
120 REG_FLD_MOD(core->base, HDMI_CEC_DBG_3, 0x1, 7, 7);
121 } else if (stat1 & 0x02) {
122 u32 dbg3 = hdmi_read_reg(core->base, HDMI_CEC_DBG_3);
123
124 cec_transmit_done(core->adap,
125 CEC_TX_STATUS_NACK |
126 CEC_TX_STATUS_MAX_RETRIES,
127 0, (dbg3 >> 4) & 7, 0, 0);
128 REG_FLD_MOD(core->base, HDMI_CEC_DBG_3, 0x1, 7, 7);
129 }
130 if (stat0 & 0x02)
131 hdmi_cec_received_msg(core);
132}
133
134static bool hdmi_cec_clear_tx_fifo(struct cec_adapter *adap)
135{
136 struct hdmi_core_data *core = cec_get_drvdata(adap);
137 int retry = HDMI_CORE_CEC_RETRY;
138 int temp;
139
140 REG_FLD_MOD(core->base, HDMI_CEC_DBG_3, 0x1, 7, 7);
141 while (retry) {
142 temp = hdmi_read_reg(core->base, HDMI_CEC_DBG_3);
143 if (FLD_GET(temp, 7, 7) == 0)
144 break;
145 retry--;
146 }
147 return retry != 0;
148}
149
150static bool hdmi_cec_clear_rx_fifo(struct cec_adapter *adap)
151{
152 struct hdmi_core_data *core = cec_get_drvdata(adap);
153 int retry = HDMI_CORE_CEC_RETRY;
154 int temp;
155
156 hdmi_write_reg(core->base, HDMI_CEC_RX_CONTROL, 0x3);
157 retry = HDMI_CORE_CEC_RETRY;
158 while (retry) {
159 temp = hdmi_read_reg(core->base, HDMI_CEC_RX_CONTROL);
160 if (FLD_GET(temp, 1, 0) == 0)
161 break;
162 retry--;
163 }
164 return retry != 0;
165}
166
167static int hdmi_cec_adap_enable(struct cec_adapter *adap, bool enable)
168{
169 struct hdmi_core_data *core = cec_get_drvdata(adap);
170 int temp, err;
171
172 if (!enable) {
173 hdmi_write_reg(core->base, HDMI_CEC_INT_ENABLE_0, 0);
174 hdmi_write_reg(core->base, HDMI_CEC_INT_ENABLE_1, 0);
175 REG_FLD_MOD(core->base, HDMI_CORE_SYS_INTR_UNMASK4, 0, 3, 3);
176 hdmi_wp_clear_irqenable(core->wp, HDMI_IRQ_CORE);
177 hdmi_wp_set_irqstatus(core->wp, HDMI_IRQ_CORE);
178 REG_FLD_MOD(core->wp->base, HDMI_WP_CLK, 0, 5, 0);
179 hdmi4_core_disable(core);
180 return 0;
181 }
182 err = hdmi4_core_enable(core);
183 if (err)
184 return err;
185
186 /*
187 * Initialize CEC clock divider: CEC needs 2MHz clock hence
188 * set the divider to 24 to get 48/24=2MHz clock
189 */
190 REG_FLD_MOD(core->wp->base, HDMI_WP_CLK, 0x18, 5, 0);
191
192 /* Clear TX FIFO */
193 if (!hdmi_cec_clear_tx_fifo(adap)) {
194 pr_err("cec-%s: could not clear TX FIFO\n", adap->name);
195 err = -EIO;
196 goto err_disable_clk;
197 }
198
199 /* Clear RX FIFO */
200 if (!hdmi_cec_clear_rx_fifo(adap)) {
201 pr_err("cec-%s: could not clear RX FIFO\n", adap->name);
202 err = -EIO;
203 goto err_disable_clk;
204 }
205
206 /* Clear CEC interrupts */
207 hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_1,
208 hdmi_read_reg(core->base, HDMI_CEC_INT_STATUS_1));
209 hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_0,
210 hdmi_read_reg(core->base, HDMI_CEC_INT_STATUS_0));
211
212 /* Enable HDMI core interrupts */
213 hdmi_wp_set_irqenable(core->wp, HDMI_IRQ_CORE);
214 /* Unmask CEC interrupt */
215 REG_FLD_MOD(core->base, HDMI_CORE_SYS_INTR_UNMASK4, 0x1, 3, 3);
216 /*
217 * Enable CEC interrupts:
218 * Transmit Buffer Full/Empty Change event
219 * Receiver FIFO Not Empty event
220 */
221 hdmi_write_reg(core->base, HDMI_CEC_INT_ENABLE_0, 0x22);
222 /*
223 * Enable CEC interrupts:
224 * Frame Retransmit Count Exceeded event
225 */
226 hdmi_write_reg(core->base, HDMI_CEC_INT_ENABLE_1, 0x02);
227
228 /* cec calibration enable (self clearing) */
229 hdmi_write_reg(core->base, HDMI_CEC_SETUP, 0x03);
230 msleep(20);
231 hdmi_write_reg(core->base, HDMI_CEC_SETUP, 0x04);
232
233 temp = hdmi_read_reg(core->base, HDMI_CEC_SETUP);
234 if (FLD_GET(temp, 4, 4) != 0) {
235 temp = FLD_MOD(temp, 0, 4, 4);
236 hdmi_write_reg(core->base, HDMI_CEC_SETUP, temp);
237
238 /*
239 * If we enabled CEC in middle of a CEC message on the bus,
240 * we could have start bit irregularity and/or short
241 * pulse event. Clear them now.
242 */
243 temp = hdmi_read_reg(core->base, HDMI_CEC_INT_STATUS_1);
244 temp = FLD_MOD(0x0, 0x5, 2, 0);
245 hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_1, temp);
246 }
247 return 0;
248
249err_disable_clk:
250 REG_FLD_MOD(core->wp->base, HDMI_WP_CLK, 0, 5, 0);
251 hdmi4_core_disable(core);
252
253 return err;
254}
255
256static int hdmi_cec_adap_log_addr(struct cec_adapter *adap, u8 log_addr)
257{
258 struct hdmi_core_data *core = cec_get_drvdata(adap);
259 u32 v;
260
261 if (log_addr == CEC_LOG_ADDR_INVALID) {
262 hdmi_write_reg(core->base, HDMI_CEC_CA_7_0, 0);
263 hdmi_write_reg(core->base, HDMI_CEC_CA_15_8, 0);
264 return 0;
265 }
266 if (log_addr <= 7) {
267 v = hdmi_read_reg(core->base, HDMI_CEC_CA_7_0);
268 v |= 1 << log_addr;
269 hdmi_write_reg(core->base, HDMI_CEC_CA_7_0, v);
270 } else {
271 v = hdmi_read_reg(core->base, HDMI_CEC_CA_15_8);
272 v |= 1 << (log_addr - 8);
273 hdmi_write_reg(core->base, HDMI_CEC_CA_15_8, v);
274 }
275 return 0;
276}
277
278static int hdmi_cec_adap_transmit(struct cec_adapter *adap, u8 attempts,
279 u32 signal_free_time, struct cec_msg *msg)
280{
281 struct hdmi_core_data *core = cec_get_drvdata(adap);
282 int temp;
283 u32 i;
284
285 /* Clear TX FIFO */
286 if (!hdmi_cec_clear_tx_fifo(adap)) {
287 pr_err("cec-%s: could not clear TX FIFO for transmit\n",
288 adap->name);
289 return -EIO;
290 }
291
292 /* Clear TX interrupts */
293 hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_0,
294 HDMI_CEC_TX_FIFO_INT_MASK);
295
296 hdmi_write_reg(core->base, HDMI_CEC_INT_STATUS_1,
297 HDMI_CEC_RETRANSMIT_CNT_INT_MASK);
298
299 /* Set the retry count */
300 REG_FLD_MOD(core->base, HDMI_CEC_DBG_3, attempts - 1, 6, 4);
301
302 /* Set the initiator addresses */
303 hdmi_write_reg(core->base, HDMI_CEC_TX_INIT, cec_msg_initiator(msg));
304
305 /* Set destination id */
306 temp = cec_msg_destination(msg);
307 if (msg->len == 1)
308 temp |= 0x80;
309 hdmi_write_reg(core->base, HDMI_CEC_TX_DEST, temp);
310 if (msg->len == 1)
311 return 0;
312
313 /* Setup command and arguments for the command */
314 hdmi_write_reg(core->base, HDMI_CEC_TX_COMMAND, msg->msg[1]);
315
316 for (i = 0; i < msg->len - 2; i++)
317 hdmi_write_reg(core->base, HDMI_CEC_TX_OPERAND + i * 4,
318 msg->msg[2 + i]);
319
320 /* Operand count */
321 hdmi_write_reg(core->base, HDMI_CEC_TRANSMIT_DATA,
322 (msg->len - 2) | 0x10);
323 return 0;
324}
325
326static const struct cec_adap_ops hdmi_cec_adap_ops = {
327 .adap_enable = hdmi_cec_adap_enable,
328 .adap_log_addr = hdmi_cec_adap_log_addr,
329 .adap_transmit = hdmi_cec_adap_transmit,
330};
331
332void hdmi4_cec_set_phys_addr(struct hdmi_core_data *core, u16 pa)
333{
334 cec_s_phys_addr(core->adap, pa, false);
335}
336
337int hdmi4_cec_init(struct platform_device *pdev, struct hdmi_core_data *core,
338 struct hdmi_wp_data *wp)
339{
340 const u32 caps = CEC_CAP_TRANSMIT | CEC_CAP_LOG_ADDRS |
341 CEC_CAP_PASSTHROUGH | CEC_CAP_RC;
342 int ret;
343
344 core->adap = cec_allocate_adapter(&hdmi_cec_adap_ops, core,
345 "omap4", caps, CEC_MAX_LOG_ADDRS);
346 ret = PTR_ERR_OR_ZERO(core->adap);
347 if (ret < 0)
348 return ret;
349 core->wp = wp;
350
351 /* Disable clock initially, hdmi_cec_adap_enable() manages it */
352 REG_FLD_MOD(core->wp->base, HDMI_WP_CLK, 0, 5, 0);
353
354 ret = cec_register_adapter(core->adap, &pdev->dev);
355 if (ret < 0) {
356 cec_delete_adapter(core->adap);
357 return ret;
358 }
359 return 0;
360}
361
362void hdmi4_cec_uninit(struct hdmi_core_data *core)
363{
364 cec_unregister_adapter(core->adap);
365}