xref: /openbmc/linux/drivers/gpu/drm/arm/hdlcd_crtc.c (revision 4f6cce39)
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 const struct drm_crtc_funcs hdlcd_crtc_funcs = {
46 	.destroy = hdlcd_crtc_cleanup,
47 	.set_config = drm_atomic_helper_set_config,
48 	.page_flip = drm_atomic_helper_page_flip,
49 	.reset = drm_atomic_helper_crtc_reset,
50 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
51 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
52 };
53 
54 static struct simplefb_format supported_formats[] = SIMPLEFB_FORMATS;
55 
56 /*
57  * Setup the HDLCD registers for decoding the pixels out of the framebuffer
58  */
59 static int hdlcd_set_pxl_fmt(struct drm_crtc *crtc)
60 {
61 	unsigned int btpp;
62 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
63 	const struct drm_framebuffer *fb = crtc->primary->state->fb;
64 	uint32_t pixel_format;
65 	struct simplefb_format *format = NULL;
66 	int i;
67 
68 	pixel_format = fb->format->format;
69 
70 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++) {
71 		if (supported_formats[i].fourcc == pixel_format)
72 			format = &supported_formats[i];
73 	}
74 
75 	if (WARN_ON(!format))
76 		return 0;
77 
78 	/* HDLCD uses 'bytes per pixel', zero means 1 byte */
79 	btpp = (format->bits_per_pixel + 7) / 8;
80 	hdlcd_write(hdlcd, HDLCD_REG_PIXEL_FORMAT, (btpp - 1) << 3);
81 
82 	/*
83 	 * The format of the HDLCD_REG_<color>_SELECT register is:
84 	 *   - bits[23:16] - default value for that color component
85 	 *   - bits[11:8]  - number of bits to extract for each color component
86 	 *   - bits[4:0]   - index of the lowest bit to extract
87 	 *
88 	 * The default color value is used when bits[11:8] are zero, when the
89 	 * pixel is outside the visible frame area or when there is a
90 	 * buffer underrun.
91 	 */
92 	hdlcd_write(hdlcd, HDLCD_REG_RED_SELECT, format->red.offset |
93 #ifdef CONFIG_DRM_HDLCD_SHOW_UNDERRUN
94 		    0x00ff0000 |	/* show underruns in red */
95 #endif
96 		    ((format->red.length & 0xf) << 8));
97 	hdlcd_write(hdlcd, HDLCD_REG_GREEN_SELECT, format->green.offset |
98 		    ((format->green.length & 0xf) << 8));
99 	hdlcd_write(hdlcd, HDLCD_REG_BLUE_SELECT, format->blue.offset |
100 		    ((format->blue.length & 0xf) << 8));
101 
102 	return 0;
103 }
104 
105 static void hdlcd_crtc_mode_set_nofb(struct drm_crtc *crtc)
106 {
107 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
108 	struct drm_display_mode *m = &crtc->state->adjusted_mode;
109 	struct videomode vm;
110 	unsigned int polarities, err;
111 
112 	vm.vfront_porch = m->crtc_vsync_start - m->crtc_vdisplay;
113 	vm.vback_porch = m->crtc_vtotal - m->crtc_vsync_end;
114 	vm.vsync_len = m->crtc_vsync_end - m->crtc_vsync_start;
115 	vm.hfront_porch = m->crtc_hsync_start - m->crtc_hdisplay;
116 	vm.hback_porch = m->crtc_htotal - m->crtc_hsync_end;
117 	vm.hsync_len = m->crtc_hsync_end - m->crtc_hsync_start;
118 
119 	polarities = HDLCD_POLARITY_DATAEN | HDLCD_POLARITY_DATA;
120 
121 	if (m->flags & DRM_MODE_FLAG_PHSYNC)
122 		polarities |= HDLCD_POLARITY_HSYNC;
123 	if (m->flags & DRM_MODE_FLAG_PVSYNC)
124 		polarities |= HDLCD_POLARITY_VSYNC;
125 
126 	/* Allow max number of outstanding requests and largest burst size */
127 	hdlcd_write(hdlcd, HDLCD_REG_BUS_OPTIONS,
128 		    HDLCD_BUS_MAX_OUTSTAND | HDLCD_BUS_BURST_16);
129 
130 	hdlcd_write(hdlcd, HDLCD_REG_V_DATA, m->crtc_vdisplay - 1);
131 	hdlcd_write(hdlcd, HDLCD_REG_V_BACK_PORCH, vm.vback_porch - 1);
132 	hdlcd_write(hdlcd, HDLCD_REG_V_FRONT_PORCH, vm.vfront_porch - 1);
133 	hdlcd_write(hdlcd, HDLCD_REG_V_SYNC, vm.vsync_len - 1);
134 	hdlcd_write(hdlcd, HDLCD_REG_H_DATA, m->crtc_hdisplay - 1);
135 	hdlcd_write(hdlcd, HDLCD_REG_H_BACK_PORCH, vm.hback_porch - 1);
136 	hdlcd_write(hdlcd, HDLCD_REG_H_FRONT_PORCH, vm.hfront_porch - 1);
137 	hdlcd_write(hdlcd, HDLCD_REG_H_SYNC, vm.hsync_len - 1);
138 	hdlcd_write(hdlcd, HDLCD_REG_POLARITIES, polarities);
139 
140 	err = hdlcd_set_pxl_fmt(crtc);
141 	if (err)
142 		return;
143 
144 	clk_set_rate(hdlcd->clk, m->crtc_clock * 1000);
145 }
146 
147 static void hdlcd_crtc_enable(struct drm_crtc *crtc)
148 {
149 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
150 
151 	clk_prepare_enable(hdlcd->clk);
152 	hdlcd_crtc_mode_set_nofb(crtc);
153 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 1);
154 	drm_crtc_vblank_on(crtc);
155 }
156 
157 static void hdlcd_crtc_disable(struct drm_crtc *crtc)
158 {
159 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
160 
161 	drm_crtc_vblank_off(crtc);
162 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
163 	clk_disable_unprepare(hdlcd->clk);
164 }
165 
166 static int hdlcd_crtc_atomic_check(struct drm_crtc *crtc,
167 				   struct drm_crtc_state *state)
168 {
169 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
170 	struct drm_display_mode *mode = &state->adjusted_mode;
171 	long rate, clk_rate = mode->clock * 1000;
172 
173 	rate = clk_round_rate(hdlcd->clk, clk_rate);
174 	if (rate != clk_rate) {
175 		/* clock required by mode not supported by hardware */
176 		return -EINVAL;
177 	}
178 
179 	return 0;
180 }
181 
182 static void hdlcd_crtc_atomic_begin(struct drm_crtc *crtc,
183 				    struct drm_crtc_state *state)
184 {
185 	struct drm_pending_vblank_event *event = crtc->state->event;
186 
187 	if (event) {
188 		crtc->state->event = NULL;
189 
190 		spin_lock_irq(&crtc->dev->event_lock);
191 		if (drm_crtc_vblank_get(crtc) == 0)
192 			drm_crtc_arm_vblank_event(crtc, event);
193 		else
194 			drm_crtc_send_vblank_event(crtc, event);
195 		spin_unlock_irq(&crtc->dev->event_lock);
196 	}
197 }
198 
199 static const struct drm_crtc_helper_funcs hdlcd_crtc_helper_funcs = {
200 	.enable		= hdlcd_crtc_enable,
201 	.disable	= hdlcd_crtc_disable,
202 	.atomic_check	= hdlcd_crtc_atomic_check,
203 	.atomic_begin	= hdlcd_crtc_atomic_begin,
204 };
205 
206 static int hdlcd_plane_atomic_check(struct drm_plane *plane,
207 				    struct drm_plane_state *state)
208 {
209 	u32 src_w, src_h;
210 
211 	src_w = state->src_w >> 16;
212 	src_h = state->src_h >> 16;
213 
214 	/* we can't do any scaling of the plane source */
215 	if ((src_w != state->crtc_w) || (src_h != state->crtc_h))
216 		return -EINVAL;
217 
218 	return 0;
219 }
220 
221 static void hdlcd_plane_atomic_update(struct drm_plane *plane,
222 				      struct drm_plane_state *state)
223 {
224 	struct drm_framebuffer *fb = plane->state->fb;
225 	struct hdlcd_drm_private *hdlcd;
226 	struct drm_gem_cma_object *gem;
227 	u32 src_w, src_h, dest_w, dest_h;
228 	dma_addr_t scanout_start;
229 
230 	if (!fb)
231 		return;
232 
233 	src_w = plane->state->src_w >> 16;
234 	src_h = plane->state->src_h >> 16;
235 	dest_w = plane->state->crtc_w;
236 	dest_h = plane->state->crtc_h;
237 	gem = drm_fb_cma_get_gem_obj(fb, 0);
238 	scanout_start = gem->paddr + fb->offsets[0] +
239 		plane->state->crtc_y * fb->pitches[0] +
240 		plane->state->crtc_x *
241 		fb->format->cpp[0];
242 
243 	hdlcd = plane->dev->dev_private;
244 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_LENGTH, fb->pitches[0]);
245 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_PITCH, fb->pitches[0]);
246 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_COUNT, dest_h - 1);
247 	hdlcd_write(hdlcd, HDLCD_REG_FB_BASE, scanout_start);
248 }
249 
250 static const struct drm_plane_helper_funcs hdlcd_plane_helper_funcs = {
251 	.atomic_check = hdlcd_plane_atomic_check,
252 	.atomic_update = hdlcd_plane_atomic_update,
253 };
254 
255 static void hdlcd_plane_destroy(struct drm_plane *plane)
256 {
257 	drm_plane_helper_disable(plane);
258 	drm_plane_cleanup(plane);
259 }
260 
261 static const struct drm_plane_funcs hdlcd_plane_funcs = {
262 	.update_plane		= drm_atomic_helper_update_plane,
263 	.disable_plane		= drm_atomic_helper_disable_plane,
264 	.destroy		= hdlcd_plane_destroy,
265 	.reset			= drm_atomic_helper_plane_reset,
266 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
267 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
268 };
269 
270 static struct drm_plane *hdlcd_plane_init(struct drm_device *drm)
271 {
272 	struct hdlcd_drm_private *hdlcd = drm->dev_private;
273 	struct drm_plane *plane = NULL;
274 	u32 formats[ARRAY_SIZE(supported_formats)], i;
275 	int ret;
276 
277 	plane = devm_kzalloc(drm->dev, sizeof(*plane), GFP_KERNEL);
278 	if (!plane)
279 		return ERR_PTR(-ENOMEM);
280 
281 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++)
282 		formats[i] = supported_formats[i].fourcc;
283 
284 	ret = drm_universal_plane_init(drm, plane, 0xff, &hdlcd_plane_funcs,
285 				       formats, ARRAY_SIZE(formats),
286 				       DRM_PLANE_TYPE_PRIMARY, NULL);
287 	if (ret) {
288 		devm_kfree(drm->dev, plane);
289 		return ERR_PTR(ret);
290 	}
291 
292 	drm_plane_helper_add(plane, &hdlcd_plane_helper_funcs);
293 	hdlcd->plane = plane;
294 
295 	return plane;
296 }
297 
298 int hdlcd_setup_crtc(struct drm_device *drm)
299 {
300 	struct hdlcd_drm_private *hdlcd = drm->dev_private;
301 	struct drm_plane *primary;
302 	int ret;
303 
304 	primary = hdlcd_plane_init(drm);
305 	if (IS_ERR(primary))
306 		return PTR_ERR(primary);
307 
308 	ret = drm_crtc_init_with_planes(drm, &hdlcd->crtc, primary, NULL,
309 					&hdlcd_crtc_funcs, NULL);
310 	if (ret) {
311 		hdlcd_plane_destroy(primary);
312 		devm_kfree(drm->dev, primary);
313 		return ret;
314 	}
315 
316 	drm_crtc_helper_add(&hdlcd->crtc, &hdlcd_crtc_helper_funcs);
317 	return 0;
318 }
319