1 /*
2  * Driver for Analog Devices ADV748X CSI-2 Transmitter
3  *
4  * Copyright (C) 2017 Renesas Electronics Corp.
5  *
6  * This program is free software; you can redistribute  it and/or modify it
7  * under  the terms of  the GNU General  Public License as published by the
8  * Free Software Foundation;  either version 2 of the  License, or (at your
9  * option) any later version.
10  */
11 
12 #include <linux/module.h>
13 #include <linux/mutex.h>
14 
15 #include <media/v4l2-ctrls.h>
16 #include <media/v4l2-device.h>
17 #include <media/v4l2-ioctl.h>
18 
19 #include "adv748x.h"
20 
21 static bool is_txa(struct adv748x_csi2 *tx)
22 {
23 	return tx == &tx->state->txa;
24 }
25 
26 static int adv748x_csi2_set_virtual_channel(struct adv748x_csi2 *tx,
27 					    unsigned int vc)
28 {
29 	return tx_write(tx, ADV748X_CSI_VC_REF, vc << ADV748X_CSI_VC_REF_SHIFT);
30 }
31 
32 /**
33  * adv748x_csi2_register_link : Register and link internal entities
34  *
35  * @tx: CSI2 private entity
36  * @v4l2_dev: Video registration device
37  * @src: Source subdevice to establish link
38  * @src_pad: Pad number of source to link to this @tx
39  *
40  * Ensure that the subdevice is registered against the v4l2_device, and link the
41  * source pad to the sink pad of the CSI2 bus entity.
42  */
43 static int adv748x_csi2_register_link(struct adv748x_csi2 *tx,
44 				      struct v4l2_device *v4l2_dev,
45 				      struct v4l2_subdev *src,
46 				      unsigned int src_pad)
47 {
48 	int enabled = MEDIA_LNK_FL_ENABLED;
49 	int ret;
50 
51 	/*
52 	 * Dynamic linking of the AFE is not supported.
53 	 * Register the links as immutable.
54 	 */
55 	enabled |= MEDIA_LNK_FL_IMMUTABLE;
56 
57 	if (!src->v4l2_dev) {
58 		ret = v4l2_device_register_subdev(v4l2_dev, src);
59 		if (ret)
60 			return ret;
61 	}
62 
63 	return media_create_pad_link(&src->entity, src_pad,
64 				     &tx->sd.entity, ADV748X_CSI2_SINK,
65 				     enabled);
66 }
67 
68 /* -----------------------------------------------------------------------------
69  * v4l2_subdev_internal_ops
70  *
71  * We use the internal registered operation to be able to ensure that our
72  * incremental subdevices (not connected in the forward path) can be registered
73  * against the resulting video path and media device.
74  */
75 
76 static int adv748x_csi2_registered(struct v4l2_subdev *sd)
77 {
78 	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
79 	struct adv748x_state *state = tx->state;
80 
81 	adv_dbg(state, "Registered %s (%s)", is_txa(tx) ? "TXA":"TXB",
82 			sd->name);
83 
84 	/*
85 	 * The adv748x hardware allows the AFE to route through the TXA, however
86 	 * this is not currently supported in this driver.
87 	 *
88 	 * Link HDMI->TXA, and AFE->TXB directly.
89 	 */
90 	if (is_txa(tx)) {
91 		return adv748x_csi2_register_link(tx, sd->v4l2_dev,
92 						  &state->hdmi.sd,
93 						  ADV748X_HDMI_SOURCE);
94 	} else {
95 		return adv748x_csi2_register_link(tx, sd->v4l2_dev,
96 						  &state->afe.sd,
97 						  ADV748X_AFE_SOURCE);
98 	}
99 }
100 
101 static const struct v4l2_subdev_internal_ops adv748x_csi2_internal_ops = {
102 	.registered = adv748x_csi2_registered,
103 };
104 
105 /* -----------------------------------------------------------------------------
106  * v4l2_subdev_video_ops
107  */
108 
109 static int adv748x_csi2_s_stream(struct v4l2_subdev *sd, int enable)
110 {
111 	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
112 	struct v4l2_subdev *src;
113 
114 	src = adv748x_get_remote_sd(&tx->pads[ADV748X_CSI2_SINK]);
115 	if (!src)
116 		return -EPIPE;
117 
118 	return v4l2_subdev_call(src, video, s_stream, enable);
119 }
120 
121 static const struct v4l2_subdev_video_ops adv748x_csi2_video_ops = {
122 	.s_stream = adv748x_csi2_s_stream,
123 };
124 
125 /* -----------------------------------------------------------------------------
126  * v4l2_subdev_pad_ops
127  *
128  * The CSI2 bus pads are ignorant to the data sizes or formats.
129  * But we must support setting the pad formats for format propagation.
130  */
131 
132 static struct v4l2_mbus_framefmt *
133 adv748x_csi2_get_pad_format(struct v4l2_subdev *sd,
134 			    struct v4l2_subdev_pad_config *cfg,
135 			    unsigned int pad, u32 which)
136 {
137 	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
138 
139 	if (which == V4L2_SUBDEV_FORMAT_TRY)
140 		return v4l2_subdev_get_try_format(sd, cfg, pad);
141 
142 	return &tx->format;
143 }
144 
145 static int adv748x_csi2_get_format(struct v4l2_subdev *sd,
146 				   struct v4l2_subdev_pad_config *cfg,
147 				   struct v4l2_subdev_format *sdformat)
148 {
149 	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
150 	struct adv748x_state *state = tx->state;
151 	struct v4l2_mbus_framefmt *mbusformat;
152 
153 	mbusformat = adv748x_csi2_get_pad_format(sd, cfg, sdformat->pad,
154 						 sdformat->which);
155 	if (!mbusformat)
156 		return -EINVAL;
157 
158 	mutex_lock(&state->mutex);
159 
160 	sdformat->format = *mbusformat;
161 
162 	mutex_unlock(&state->mutex);
163 
164 	return 0;
165 }
166 
167 static int adv748x_csi2_set_format(struct v4l2_subdev *sd,
168 				   struct v4l2_subdev_pad_config *cfg,
169 				   struct v4l2_subdev_format *sdformat)
170 {
171 	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
172 	struct adv748x_state *state = tx->state;
173 	struct v4l2_mbus_framefmt *mbusformat;
174 	int ret = 0;
175 
176 	mbusformat = adv748x_csi2_get_pad_format(sd, cfg, sdformat->pad,
177 						 sdformat->which);
178 	if (!mbusformat)
179 		return -EINVAL;
180 
181 	mutex_lock(&state->mutex);
182 
183 	if (sdformat->pad == ADV748X_CSI2_SOURCE) {
184 		const struct v4l2_mbus_framefmt *sink_fmt;
185 
186 		sink_fmt = adv748x_csi2_get_pad_format(sd, cfg,
187 						       ADV748X_CSI2_SINK,
188 						       sdformat->which);
189 
190 		if (!sink_fmt) {
191 			ret = -EINVAL;
192 			goto unlock;
193 		}
194 
195 		sdformat->format = *sink_fmt;
196 	}
197 
198 	*mbusformat = sdformat->format;
199 
200 unlock:
201 	mutex_unlock(&state->mutex);
202 
203 	return ret;
204 }
205 
206 static const struct v4l2_subdev_pad_ops adv748x_csi2_pad_ops = {
207 	.get_fmt = adv748x_csi2_get_format,
208 	.set_fmt = adv748x_csi2_set_format,
209 };
210 
211 /* -----------------------------------------------------------------------------
212  * v4l2_subdev_ops
213  */
214 
215 static const struct v4l2_subdev_ops adv748x_csi2_ops = {
216 	.video = &adv748x_csi2_video_ops,
217 	.pad = &adv748x_csi2_pad_ops,
218 };
219 
220 /* -----------------------------------------------------------------------------
221  * Subdev module and controls
222  */
223 
224 int adv748x_csi2_set_pixelrate(struct v4l2_subdev *sd, s64 rate)
225 {
226 	struct adv748x_csi2 *tx = adv748x_sd_to_csi2(sd);
227 
228 	if (!tx->pixel_rate)
229 		return -EINVAL;
230 
231 	return v4l2_ctrl_s_ctrl_int64(tx->pixel_rate, rate);
232 }
233 
234 static int adv748x_csi2_s_ctrl(struct v4l2_ctrl *ctrl)
235 {
236 	switch (ctrl->id) {
237 	case V4L2_CID_PIXEL_RATE:
238 		return 0;
239 	default:
240 		return -EINVAL;
241 	}
242 }
243 
244 static const struct v4l2_ctrl_ops adv748x_csi2_ctrl_ops = {
245 	.s_ctrl = adv748x_csi2_s_ctrl,
246 };
247 
248 static int adv748x_csi2_init_controls(struct adv748x_csi2 *tx)
249 {
250 
251 	v4l2_ctrl_handler_init(&tx->ctrl_hdl, 1);
252 
253 	tx->pixel_rate = v4l2_ctrl_new_std(&tx->ctrl_hdl,
254 					   &adv748x_csi2_ctrl_ops,
255 					   V4L2_CID_PIXEL_RATE, 1, INT_MAX,
256 					   1, 1);
257 
258 	tx->sd.ctrl_handler = &tx->ctrl_hdl;
259 	if (tx->ctrl_hdl.error) {
260 		v4l2_ctrl_handler_free(&tx->ctrl_hdl);
261 		return tx->ctrl_hdl.error;
262 	}
263 
264 	return v4l2_ctrl_handler_setup(&tx->ctrl_hdl);
265 }
266 
267 int adv748x_csi2_init(struct adv748x_state *state, struct adv748x_csi2 *tx)
268 {
269 	struct device_node *ep;
270 	int ret;
271 
272 	/* We can not use container_of to get back to the state with two TXs */
273 	tx->state = state;
274 	tx->page = is_txa(tx) ? ADV748X_PAGE_TXA : ADV748X_PAGE_TXB;
275 
276 	ep = state->endpoints[is_txa(tx) ? ADV748X_PORT_TXA : ADV748X_PORT_TXB];
277 	if (!ep) {
278 		adv_err(state, "No endpoint found for %s\n",
279 				is_txa(tx) ? "txa" : "txb");
280 		return -ENODEV;
281 	}
282 
283 	/* Initialise the virtual channel */
284 	adv748x_csi2_set_virtual_channel(tx, 0);
285 
286 	adv748x_subdev_init(&tx->sd, state, &adv748x_csi2_ops,
287 			    MEDIA_ENT_F_VID_IF_BRIDGE,
288 			    is_txa(tx) ? "txa" : "txb");
289 
290 	/* Ensure that matching is based upon the endpoint fwnodes */
291 	tx->sd.fwnode = of_fwnode_handle(ep);
292 
293 	/* Register internal ops for incremental subdev registration */
294 	tx->sd.internal_ops = &adv748x_csi2_internal_ops;
295 
296 	tx->pads[ADV748X_CSI2_SINK].flags = MEDIA_PAD_FL_SINK;
297 	tx->pads[ADV748X_CSI2_SOURCE].flags = MEDIA_PAD_FL_SOURCE;
298 
299 	ret = media_entity_pads_init(&tx->sd.entity, ADV748X_CSI2_NR_PADS,
300 				     tx->pads);
301 	if (ret)
302 		return ret;
303 
304 	ret = adv748x_csi2_init_controls(tx);
305 	if (ret)
306 		goto err_free_media;
307 
308 	ret = v4l2_async_register_subdev(&tx->sd);
309 	if (ret)
310 		goto err_free_ctrl;
311 
312 	return 0;
313 
314 err_free_ctrl:
315 	v4l2_ctrl_handler_free(&tx->ctrl_hdl);
316 err_free_media:
317 	media_entity_cleanup(&tx->sd.entity);
318 
319 	return ret;
320 }
321 
322 void adv748x_csi2_cleanup(struct adv748x_csi2 *tx)
323 {
324 	v4l2_async_unregister_subdev(&tx->sd);
325 	media_entity_cleanup(&tx->sd.entity);
326 	v4l2_ctrl_handler_free(&tx->ctrl_hdl);
327 }
328