xref: /openbmc/linux/drivers/gpu/drm/arm/hdlcd_crtc.c (revision 9125f19b)
1 /*
2  * Copyright (C) 2013-2015 ARM Limited
3  * Author: Liviu Dudau <Liviu.Dudau@arm.com>
4  *
5  * This file is subject to the terms and conditions of the GNU General Public
6  * License.  See the file COPYING in the main directory of this archive
7  * for more details.
8  *
9  *  Implementation of a CRTC class for the HDLCD driver.
10  */
11 
12 #include <drm/drmP.h>
13 #include <drm/drm_atomic_helper.h>
14 #include <drm/drm_crtc.h>
15 #include <drm/drm_crtc_helper.h>
16 #include <drm/drm_fb_helper.h>
17 #include <drm/drm_fb_cma_helper.h>
18 #include <drm/drm_gem_cma_helper.h>
19 #include <drm/drm_of.h>
20 #include <drm/drm_plane_helper.h>
21 #include <linux/clk.h>
22 #include <linux/of_graph.h>
23 #include <linux/platform_data/simplefb.h>
24 #include <video/videomode.h>
25 
26 #include "hdlcd_drv.h"
27 #include "hdlcd_regs.h"
28 
29 /*
30  * The HDLCD controller is a dumb RGB streamer that gets connected to
31  * a single HDMI transmitter or in the case of the ARM Models it gets
32  * emulated by the software that does the actual rendering.
33  *
34  */
35 
36 static const struct drm_crtc_funcs hdlcd_crtc_funcs = {
37 	.destroy = drm_crtc_cleanup,
38 	.set_config = drm_atomic_helper_set_config,
39 	.page_flip = drm_atomic_helper_page_flip,
40 	.reset = drm_atomic_helper_crtc_reset,
41 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
42 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
43 };
44 
45 static struct simplefb_format supported_formats[] = SIMPLEFB_FORMATS;
46 
47 /*
48  * Setup the HDLCD registers for decoding the pixels out of the framebuffer
49  */
50 static int hdlcd_set_pxl_fmt(struct drm_crtc *crtc)
51 {
52 	unsigned int btpp;
53 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
54 	uint32_t pixel_format;
55 	struct simplefb_format *format = NULL;
56 	int i;
57 
58 	pixel_format = crtc->primary->state->fb->pixel_format;
59 
60 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++) {
61 		if (supported_formats[i].fourcc == pixel_format)
62 			format = &supported_formats[i];
63 	}
64 
65 	if (WARN_ON(!format))
66 		return 0;
67 
68 	/* HDLCD uses 'bytes per pixel', zero means 1 byte */
69 	btpp = (format->bits_per_pixel + 7) / 8;
70 	hdlcd_write(hdlcd, HDLCD_REG_PIXEL_FORMAT, (btpp - 1) << 3);
71 
72 	/*
73 	 * The format of the HDLCD_REG_<color>_SELECT register is:
74 	 *   - bits[23:16] - default value for that color component
75 	 *   - bits[11:8]  - number of bits to extract for each color component
76 	 *   - bits[4:0]   - index of the lowest bit to extract
77 	 *
78 	 * The default color value is used when bits[11:8] are zero, when the
79 	 * pixel is outside the visible frame area or when there is a
80 	 * buffer underrun.
81 	 */
82 	hdlcd_write(hdlcd, HDLCD_REG_RED_SELECT, format->red.offset |
83 #ifdef CONFIG_DRM_HDLCD_SHOW_UNDERRUN
84 		    0x00ff0000 |	/* show underruns in red */
85 #endif
86 		    ((format->red.length & 0xf) << 8));
87 	hdlcd_write(hdlcd, HDLCD_REG_GREEN_SELECT, format->green.offset |
88 		    ((format->green.length & 0xf) << 8));
89 	hdlcd_write(hdlcd, HDLCD_REG_BLUE_SELECT, format->blue.offset |
90 		    ((format->blue.length & 0xf) << 8));
91 
92 	return 0;
93 }
94 
95 static void hdlcd_crtc_mode_set_nofb(struct drm_crtc *crtc)
96 {
97 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
98 	struct drm_display_mode *m = &crtc->state->adjusted_mode;
99 	struct videomode vm;
100 	unsigned int polarities, line_length, err;
101 
102 	vm.vfront_porch = m->crtc_vsync_start - m->crtc_vdisplay;
103 	vm.vback_porch = m->crtc_vtotal - m->crtc_vsync_end;
104 	vm.vsync_len = m->crtc_vsync_end - m->crtc_vsync_start;
105 	vm.hfront_porch = m->crtc_hsync_start - m->crtc_hdisplay;
106 	vm.hback_porch = m->crtc_htotal - m->crtc_hsync_end;
107 	vm.hsync_len = m->crtc_hsync_end - m->crtc_hsync_start;
108 
109 	polarities = HDLCD_POLARITY_DATAEN | HDLCD_POLARITY_DATA;
110 
111 	if (m->flags & DRM_MODE_FLAG_PHSYNC)
112 		polarities |= HDLCD_POLARITY_HSYNC;
113 	if (m->flags & DRM_MODE_FLAG_PVSYNC)
114 		polarities |= HDLCD_POLARITY_VSYNC;
115 
116 	line_length = crtc->primary->state->fb->pitches[0];
117 
118 	/* Allow max number of outstanding requests and largest burst size */
119 	hdlcd_write(hdlcd, HDLCD_REG_BUS_OPTIONS,
120 		    HDLCD_BUS_MAX_OUTSTAND | HDLCD_BUS_BURST_16);
121 
122 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_LENGTH, line_length);
123 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_PITCH, line_length);
124 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_COUNT, m->crtc_vdisplay - 1);
125 	hdlcd_write(hdlcd, HDLCD_REG_V_DATA, m->crtc_vdisplay - 1);
126 	hdlcd_write(hdlcd, HDLCD_REG_V_BACK_PORCH, vm.vback_porch - 1);
127 	hdlcd_write(hdlcd, HDLCD_REG_V_FRONT_PORCH, vm.vfront_porch - 1);
128 	hdlcd_write(hdlcd, HDLCD_REG_V_SYNC, vm.vsync_len - 1);
129 	hdlcd_write(hdlcd, HDLCD_REG_H_BACK_PORCH, vm.hback_porch - 1);
130 	hdlcd_write(hdlcd, HDLCD_REG_H_FRONT_PORCH, vm.hfront_porch - 1);
131 	hdlcd_write(hdlcd, HDLCD_REG_H_SYNC, vm.hsync_len - 1);
132 	hdlcd_write(hdlcd, HDLCD_REG_H_DATA, m->crtc_hdisplay - 1);
133 	hdlcd_write(hdlcd, HDLCD_REG_POLARITIES, polarities);
134 
135 	err = hdlcd_set_pxl_fmt(crtc);
136 	if (err)
137 		return;
138 
139 	clk_set_rate(hdlcd->clk, m->crtc_clock * 1000);
140 }
141 
142 static void hdlcd_crtc_enable(struct drm_crtc *crtc)
143 {
144 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
145 
146 	clk_prepare_enable(hdlcd->clk);
147 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 1);
148 	drm_crtc_vblank_on(crtc);
149 }
150 
151 static void hdlcd_crtc_disable(struct drm_crtc *crtc)
152 {
153 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
154 
155 	if (!crtc->primary->fb)
156 		return;
157 
158 	clk_disable_unprepare(hdlcd->clk);
159 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
160 	drm_crtc_vblank_off(crtc);
161 }
162 
163 static int hdlcd_crtc_atomic_check(struct drm_crtc *crtc,
164 				   struct drm_crtc_state *state)
165 {
166 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
167 	struct drm_display_mode *mode = &state->adjusted_mode;
168 	long rate, clk_rate = mode->clock * 1000;
169 
170 	rate = clk_round_rate(hdlcd->clk, clk_rate);
171 	if (rate != clk_rate) {
172 		/* clock required by mode not supported by hardware */
173 		return -EINVAL;
174 	}
175 
176 	return 0;
177 }
178 
179 static void hdlcd_crtc_atomic_begin(struct drm_crtc *crtc,
180 				    struct drm_crtc_state *state)
181 {
182 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
183 	unsigned long flags;
184 
185 	if (crtc->state->event) {
186 		struct drm_pending_vblank_event *event = crtc->state->event;
187 
188 		crtc->state->event = NULL;
189 		event->pipe = drm_crtc_index(crtc);
190 
191 		WARN_ON(drm_crtc_vblank_get(crtc) != 0);
192 
193 		spin_lock_irqsave(&crtc->dev->event_lock, flags);
194 		list_add_tail(&event->base.link, &hdlcd->event_list);
195 		spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
196 	}
197 }
198 
199 static void hdlcd_crtc_atomic_flush(struct drm_crtc *crtc,
200 				    struct drm_crtc_state *state)
201 {
202 }
203 
204 static bool hdlcd_crtc_mode_fixup(struct drm_crtc *crtc,
205 			const struct drm_display_mode *mode,
206 			struct drm_display_mode *adjusted_mode)
207 {
208 	return true;
209 }
210 
211 static const struct drm_crtc_helper_funcs hdlcd_crtc_helper_funcs = {
212 	.mode_fixup	= hdlcd_crtc_mode_fixup,
213 	.mode_set	= drm_helper_crtc_mode_set,
214 	.mode_set_base	= drm_helper_crtc_mode_set_base,
215 	.mode_set_nofb	= hdlcd_crtc_mode_set_nofb,
216 	.enable		= hdlcd_crtc_enable,
217 	.disable	= hdlcd_crtc_disable,
218 	.prepare	= hdlcd_crtc_disable,
219 	.commit		= hdlcd_crtc_enable,
220 	.atomic_check	= hdlcd_crtc_atomic_check,
221 	.atomic_begin	= hdlcd_crtc_atomic_begin,
222 	.atomic_flush	= hdlcd_crtc_atomic_flush,
223 };
224 
225 static int hdlcd_plane_atomic_check(struct drm_plane *plane,
226 				    struct drm_plane_state *state)
227 {
228 	return 0;
229 }
230 
231 static void hdlcd_plane_atomic_update(struct drm_plane *plane,
232 				      struct drm_plane_state *state)
233 {
234 	struct hdlcd_drm_private *hdlcd;
235 	struct drm_gem_cma_object *gem;
236 	dma_addr_t scanout_start;
237 
238 	if (!plane->state->crtc || !plane->state->fb)
239 		return;
240 
241 	hdlcd = crtc_to_hdlcd_priv(plane->state->crtc);
242 	gem = drm_fb_cma_get_gem_obj(plane->state->fb, 0);
243 	scanout_start = gem->paddr;
244 	hdlcd_write(hdlcd, HDLCD_REG_FB_BASE, scanout_start);
245 }
246 
247 static const struct drm_plane_helper_funcs hdlcd_plane_helper_funcs = {
248 	.prepare_fb = NULL,
249 	.cleanup_fb = NULL,
250 	.atomic_check = hdlcd_plane_atomic_check,
251 	.atomic_update = hdlcd_plane_atomic_update,
252 };
253 
254 static void hdlcd_plane_destroy(struct drm_plane *plane)
255 {
256 	drm_plane_helper_disable(plane);
257 	drm_plane_cleanup(plane);
258 }
259 
260 static const struct drm_plane_funcs hdlcd_plane_funcs = {
261 	.update_plane		= drm_atomic_helper_update_plane,
262 	.disable_plane		= drm_atomic_helper_disable_plane,
263 	.destroy		= hdlcd_plane_destroy,
264 	.reset			= drm_atomic_helper_plane_reset,
265 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
266 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
267 };
268 
269 static struct drm_plane *hdlcd_plane_init(struct drm_device *drm)
270 {
271 	struct hdlcd_drm_private *hdlcd = drm->dev_private;
272 	struct drm_plane *plane = NULL;
273 	u32 formats[ARRAY_SIZE(supported_formats)], i;
274 	int ret;
275 
276 	plane = devm_kzalloc(drm->dev, sizeof(*plane), GFP_KERNEL);
277 	if (!plane)
278 		return ERR_PTR(-ENOMEM);
279 
280 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++)
281 		formats[i] = supported_formats[i].fourcc;
282 
283 	ret = drm_universal_plane_init(drm, plane, 0xff, &hdlcd_plane_funcs,
284 				       formats, ARRAY_SIZE(formats),
285 				       DRM_PLANE_TYPE_PRIMARY, NULL);
286 	if (ret) {
287 		devm_kfree(drm->dev, plane);
288 		return ERR_PTR(ret);
289 	}
290 
291 	drm_plane_helper_add(plane, &hdlcd_plane_helper_funcs);
292 	hdlcd->plane = plane;
293 
294 	return plane;
295 }
296 
297 void hdlcd_crtc_suspend(struct drm_crtc *crtc)
298 {
299 	hdlcd_crtc_disable(crtc);
300 }
301 
302 void hdlcd_crtc_resume(struct drm_crtc *crtc)
303 {
304 	hdlcd_crtc_enable(crtc);
305 }
306 
307 int hdlcd_setup_crtc(struct drm_device *drm)
308 {
309 	struct hdlcd_drm_private *hdlcd = drm->dev_private;
310 	struct drm_plane *primary;
311 	int ret;
312 
313 	primary = hdlcd_plane_init(drm);
314 	if (IS_ERR(primary))
315 		return PTR_ERR(primary);
316 
317 	ret = drm_crtc_init_with_planes(drm, &hdlcd->crtc, primary, NULL,
318 					&hdlcd_crtc_funcs, NULL);
319 	if (ret) {
320 		hdlcd_plane_destroy(primary);
321 		devm_kfree(drm->dev, primary);
322 		return ret;
323 	}
324 
325 	drm_crtc_helper_add(&hdlcd->crtc, &hdlcd_crtc_helper_funcs);
326 	return 0;
327 }
328