xref: /openbmc/linux/drivers/gpu/drm/arm/hdlcd_crtc.c (revision f7c35abe)
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 void hdlcd_crtc_cleanup(struct drm_crtc *crtc)
37 {
38 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
39 
40 	/* stop the controller on cleanup */
41 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
42 	drm_crtc_cleanup(crtc);
43 }
44 
45 static int hdlcd_crtc_enable_vblank(struct drm_crtc *crtc)
46 {
47 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
48 	unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
49 
50 	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask | HDLCD_INTERRUPT_VSYNC);
51 
52 	return 0;
53 }
54 
55 static void hdlcd_crtc_disable_vblank(struct drm_crtc *crtc)
56 {
57 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
58 	unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
59 
60 	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask & ~HDLCD_INTERRUPT_VSYNC);
61 }
62 
63 static const struct drm_crtc_funcs hdlcd_crtc_funcs = {
64 	.destroy = hdlcd_crtc_cleanup,
65 	.set_config = drm_atomic_helper_set_config,
66 	.page_flip = drm_atomic_helper_page_flip,
67 	.reset = drm_atomic_helper_crtc_reset,
68 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
69 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
70 	.enable_vblank = hdlcd_crtc_enable_vblank,
71 	.disable_vblank = hdlcd_crtc_disable_vblank,
72 };
73 
74 static struct simplefb_format supported_formats[] = SIMPLEFB_FORMATS;
75 
76 /*
77  * Setup the HDLCD registers for decoding the pixels out of the framebuffer
78  */
79 static int hdlcd_set_pxl_fmt(struct drm_crtc *crtc)
80 {
81 	unsigned int btpp;
82 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
83 	const struct drm_framebuffer *fb = crtc->primary->state->fb;
84 	uint32_t pixel_format;
85 	struct simplefb_format *format = NULL;
86 	int i;
87 
88 	pixel_format = fb->format->format;
89 
90 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++) {
91 		if (supported_formats[i].fourcc == pixel_format)
92 			format = &supported_formats[i];
93 	}
94 
95 	if (WARN_ON(!format))
96 		return 0;
97 
98 	/* HDLCD uses 'bytes per pixel', zero means 1 byte */
99 	btpp = (format->bits_per_pixel + 7) / 8;
100 	hdlcd_write(hdlcd, HDLCD_REG_PIXEL_FORMAT, (btpp - 1) << 3);
101 
102 	/*
103 	 * The format of the HDLCD_REG_<color>_SELECT register is:
104 	 *   - bits[23:16] - default value for that color component
105 	 *   - bits[11:8]  - number of bits to extract for each color component
106 	 *   - bits[4:0]   - index of the lowest bit to extract
107 	 *
108 	 * The default color value is used when bits[11:8] are zero, when the
109 	 * pixel is outside the visible frame area or when there is a
110 	 * buffer underrun.
111 	 */
112 	hdlcd_write(hdlcd, HDLCD_REG_RED_SELECT, format->red.offset |
113 #ifdef CONFIG_DRM_HDLCD_SHOW_UNDERRUN
114 		    0x00ff0000 |	/* show underruns in red */
115 #endif
116 		    ((format->red.length & 0xf) << 8));
117 	hdlcd_write(hdlcd, HDLCD_REG_GREEN_SELECT, format->green.offset |
118 		    ((format->green.length & 0xf) << 8));
119 	hdlcd_write(hdlcd, HDLCD_REG_BLUE_SELECT, format->blue.offset |
120 		    ((format->blue.length & 0xf) << 8));
121 
122 	return 0;
123 }
124 
125 static void hdlcd_crtc_mode_set_nofb(struct drm_crtc *crtc)
126 {
127 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
128 	struct drm_display_mode *m = &crtc->state->adjusted_mode;
129 	struct videomode vm;
130 	unsigned int polarities, err;
131 
132 	vm.vfront_porch = m->crtc_vsync_start - m->crtc_vdisplay;
133 	vm.vback_porch = m->crtc_vtotal - m->crtc_vsync_end;
134 	vm.vsync_len = m->crtc_vsync_end - m->crtc_vsync_start;
135 	vm.hfront_porch = m->crtc_hsync_start - m->crtc_hdisplay;
136 	vm.hback_porch = m->crtc_htotal - m->crtc_hsync_end;
137 	vm.hsync_len = m->crtc_hsync_end - m->crtc_hsync_start;
138 
139 	polarities = HDLCD_POLARITY_DATAEN | HDLCD_POLARITY_DATA;
140 
141 	if (m->flags & DRM_MODE_FLAG_PHSYNC)
142 		polarities |= HDLCD_POLARITY_HSYNC;
143 	if (m->flags & DRM_MODE_FLAG_PVSYNC)
144 		polarities |= HDLCD_POLARITY_VSYNC;
145 
146 	/* Allow max number of outstanding requests and largest burst size */
147 	hdlcd_write(hdlcd, HDLCD_REG_BUS_OPTIONS,
148 		    HDLCD_BUS_MAX_OUTSTAND | HDLCD_BUS_BURST_16);
149 
150 	hdlcd_write(hdlcd, HDLCD_REG_V_DATA, m->crtc_vdisplay - 1);
151 	hdlcd_write(hdlcd, HDLCD_REG_V_BACK_PORCH, vm.vback_porch - 1);
152 	hdlcd_write(hdlcd, HDLCD_REG_V_FRONT_PORCH, vm.vfront_porch - 1);
153 	hdlcd_write(hdlcd, HDLCD_REG_V_SYNC, vm.vsync_len - 1);
154 	hdlcd_write(hdlcd, HDLCD_REG_H_DATA, m->crtc_hdisplay - 1);
155 	hdlcd_write(hdlcd, HDLCD_REG_H_BACK_PORCH, vm.hback_porch - 1);
156 	hdlcd_write(hdlcd, HDLCD_REG_H_FRONT_PORCH, vm.hfront_porch - 1);
157 	hdlcd_write(hdlcd, HDLCD_REG_H_SYNC, vm.hsync_len - 1);
158 	hdlcd_write(hdlcd, HDLCD_REG_POLARITIES, polarities);
159 
160 	err = hdlcd_set_pxl_fmt(crtc);
161 	if (err)
162 		return;
163 
164 	clk_set_rate(hdlcd->clk, m->crtc_clock * 1000);
165 }
166 
167 static void hdlcd_crtc_enable(struct drm_crtc *crtc)
168 {
169 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
170 
171 	clk_prepare_enable(hdlcd->clk);
172 	hdlcd_crtc_mode_set_nofb(crtc);
173 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 1);
174 	drm_crtc_vblank_on(crtc);
175 }
176 
177 static void hdlcd_crtc_disable(struct drm_crtc *crtc)
178 {
179 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
180 
181 	drm_crtc_vblank_off(crtc);
182 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
183 	clk_disable_unprepare(hdlcd->clk);
184 }
185 
186 static int hdlcd_crtc_atomic_check(struct drm_crtc *crtc,
187 				   struct drm_crtc_state *state)
188 {
189 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
190 	struct drm_display_mode *mode = &state->adjusted_mode;
191 	long rate, clk_rate = mode->clock * 1000;
192 
193 	rate = clk_round_rate(hdlcd->clk, clk_rate);
194 	if (rate != clk_rate) {
195 		/* clock required by mode not supported by hardware */
196 		return -EINVAL;
197 	}
198 
199 	return 0;
200 }
201 
202 static void hdlcd_crtc_atomic_begin(struct drm_crtc *crtc,
203 				    struct drm_crtc_state *state)
204 {
205 	struct drm_pending_vblank_event *event = crtc->state->event;
206 
207 	if (event) {
208 		crtc->state->event = NULL;
209 
210 		spin_lock_irq(&crtc->dev->event_lock);
211 		if (drm_crtc_vblank_get(crtc) == 0)
212 			drm_crtc_arm_vblank_event(crtc, event);
213 		else
214 			drm_crtc_send_vblank_event(crtc, event);
215 		spin_unlock_irq(&crtc->dev->event_lock);
216 	}
217 }
218 
219 static const struct drm_crtc_helper_funcs hdlcd_crtc_helper_funcs = {
220 	.enable		= hdlcd_crtc_enable,
221 	.disable	= hdlcd_crtc_disable,
222 	.atomic_check	= hdlcd_crtc_atomic_check,
223 	.atomic_begin	= hdlcd_crtc_atomic_begin,
224 };
225 
226 static int hdlcd_plane_atomic_check(struct drm_plane *plane,
227 				    struct drm_plane_state *state)
228 {
229 	u32 src_w, src_h;
230 
231 	src_w = state->src_w >> 16;
232 	src_h = state->src_h >> 16;
233 
234 	/* we can't do any scaling of the plane source */
235 	if ((src_w != state->crtc_w) || (src_h != state->crtc_h))
236 		return -EINVAL;
237 
238 	return 0;
239 }
240 
241 static void hdlcd_plane_atomic_update(struct drm_plane *plane,
242 				      struct drm_plane_state *state)
243 {
244 	struct drm_framebuffer *fb = plane->state->fb;
245 	struct hdlcd_drm_private *hdlcd;
246 	struct drm_gem_cma_object *gem;
247 	u32 src_w, src_h, dest_w, dest_h;
248 	dma_addr_t scanout_start;
249 
250 	if (!fb)
251 		return;
252 
253 	src_w = plane->state->src_w >> 16;
254 	src_h = plane->state->src_h >> 16;
255 	dest_w = plane->state->crtc_w;
256 	dest_h = plane->state->crtc_h;
257 	gem = drm_fb_cma_get_gem_obj(fb, 0);
258 	scanout_start = gem->paddr + fb->offsets[0] +
259 		plane->state->crtc_y * fb->pitches[0] +
260 		plane->state->crtc_x *
261 		fb->format->cpp[0];
262 
263 	hdlcd = plane->dev->dev_private;
264 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_LENGTH, fb->pitches[0]);
265 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_PITCH, fb->pitches[0]);
266 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_COUNT, dest_h - 1);
267 	hdlcd_write(hdlcd, HDLCD_REG_FB_BASE, scanout_start);
268 }
269 
270 static const struct drm_plane_helper_funcs hdlcd_plane_helper_funcs = {
271 	.atomic_check = hdlcd_plane_atomic_check,
272 	.atomic_update = hdlcd_plane_atomic_update,
273 };
274 
275 static void hdlcd_plane_destroy(struct drm_plane *plane)
276 {
277 	drm_plane_helper_disable(plane);
278 	drm_plane_cleanup(plane);
279 }
280 
281 static const struct drm_plane_funcs hdlcd_plane_funcs = {
282 	.update_plane		= drm_atomic_helper_update_plane,
283 	.disable_plane		= drm_atomic_helper_disable_plane,
284 	.destroy		= hdlcd_plane_destroy,
285 	.reset			= drm_atomic_helper_plane_reset,
286 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
287 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
288 };
289 
290 static struct drm_plane *hdlcd_plane_init(struct drm_device *drm)
291 {
292 	struct hdlcd_drm_private *hdlcd = drm->dev_private;
293 	struct drm_plane *plane = NULL;
294 	u32 formats[ARRAY_SIZE(supported_formats)], i;
295 	int ret;
296 
297 	plane = devm_kzalloc(drm->dev, sizeof(*plane), GFP_KERNEL);
298 	if (!plane)
299 		return ERR_PTR(-ENOMEM);
300 
301 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++)
302 		formats[i] = supported_formats[i].fourcc;
303 
304 	ret = drm_universal_plane_init(drm, plane, 0xff, &hdlcd_plane_funcs,
305 				       formats, ARRAY_SIZE(formats),
306 				       DRM_PLANE_TYPE_PRIMARY, NULL);
307 	if (ret) {
308 		devm_kfree(drm->dev, plane);
309 		return ERR_PTR(ret);
310 	}
311 
312 	drm_plane_helper_add(plane, &hdlcd_plane_helper_funcs);
313 	hdlcd->plane = plane;
314 
315 	return plane;
316 }
317 
318 int hdlcd_setup_crtc(struct drm_device *drm)
319 {
320 	struct hdlcd_drm_private *hdlcd = drm->dev_private;
321 	struct drm_plane *primary;
322 	int ret;
323 
324 	primary = hdlcd_plane_init(drm);
325 	if (IS_ERR(primary))
326 		return PTR_ERR(primary);
327 
328 	ret = drm_crtc_init_with_planes(drm, &hdlcd->crtc, primary, NULL,
329 					&hdlcd_crtc_funcs, NULL);
330 	if (ret) {
331 		hdlcd_plane_destroy(primary);
332 		devm_kfree(drm->dev, primary);
333 		return ret;
334 	}
335 
336 	drm_crtc_helper_add(&hdlcd->crtc, &hdlcd_crtc_helper_funcs);
337 	return 0;
338 }
339