xref: /openbmc/linux/drivers/gpu/drm/arm/hdlcd_crtc.c (revision 6726d552)
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 <linux/clk.h>
13 #include <linux/of_graph.h>
14 #include <linux/platform_data/simplefb.h>
15 
16 #include <video/videomode.h>
17 
18 #include <drm/drm_atomic.h>
19 #include <drm/drm_atomic_helper.h>
20 #include <drm/drm_crtc.h>
21 #include <drm/drm_fb_cma_helper.h>
22 #include <drm/drm_fb_helper.h>
23 #include <drm/drm_framebuffer.h>
24 #include <drm/drm_gem_cma_helper.h>
25 #include <drm/drm_of.h>
26 #include <drm/drm_plane_helper.h>
27 #include <drm/drm_probe_helper.h>
28 #include <drm/drm_vblank.h>
29 
30 #include "hdlcd_drv.h"
31 #include "hdlcd_regs.h"
32 
33 /*
34  * The HDLCD controller is a dumb RGB streamer that gets connected to
35  * a single HDMI transmitter or in the case of the ARM Models it gets
36  * emulated by the software that does the actual rendering.
37  *
38  */
39 
40 static void hdlcd_crtc_cleanup(struct drm_crtc *crtc)
41 {
42 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
43 
44 	/* stop the controller on cleanup */
45 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
46 	drm_crtc_cleanup(crtc);
47 }
48 
49 static int hdlcd_crtc_enable_vblank(struct drm_crtc *crtc)
50 {
51 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
52 	unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
53 
54 	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask | HDLCD_INTERRUPT_VSYNC);
55 
56 	return 0;
57 }
58 
59 static void hdlcd_crtc_disable_vblank(struct drm_crtc *crtc)
60 {
61 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
62 	unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
63 
64 	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask & ~HDLCD_INTERRUPT_VSYNC);
65 }
66 
67 static const struct drm_crtc_funcs hdlcd_crtc_funcs = {
68 	.destroy = hdlcd_crtc_cleanup,
69 	.set_config = drm_atomic_helper_set_config,
70 	.page_flip = drm_atomic_helper_page_flip,
71 	.reset = drm_atomic_helper_crtc_reset,
72 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
73 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
74 	.enable_vblank = hdlcd_crtc_enable_vblank,
75 	.disable_vblank = hdlcd_crtc_disable_vblank,
76 };
77 
78 static struct simplefb_format supported_formats[] = SIMPLEFB_FORMATS;
79 
80 /*
81  * Setup the HDLCD registers for decoding the pixels out of the framebuffer
82  */
83 static int hdlcd_set_pxl_fmt(struct drm_crtc *crtc)
84 {
85 	unsigned int btpp;
86 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
87 	const struct drm_framebuffer *fb = crtc->primary->state->fb;
88 	uint32_t pixel_format;
89 	struct simplefb_format *format = NULL;
90 	int i;
91 
92 	pixel_format = fb->format->format;
93 
94 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++) {
95 		if (supported_formats[i].fourcc == pixel_format)
96 			format = &supported_formats[i];
97 	}
98 
99 	if (WARN_ON(!format))
100 		return 0;
101 
102 	/* HDLCD uses 'bytes per pixel', zero means 1 byte */
103 	btpp = (format->bits_per_pixel + 7) / 8;
104 	hdlcd_write(hdlcd, HDLCD_REG_PIXEL_FORMAT, (btpp - 1) << 3);
105 
106 	/*
107 	 * The format of the HDLCD_REG_<color>_SELECT register is:
108 	 *   - bits[23:16] - default value for that color component
109 	 *   - bits[11:8]  - number of bits to extract for each color component
110 	 *   - bits[4:0]   - index of the lowest bit to extract
111 	 *
112 	 * The default color value is used when bits[11:8] are zero, when the
113 	 * pixel is outside the visible frame area or when there is a
114 	 * buffer underrun.
115 	 */
116 	hdlcd_write(hdlcd, HDLCD_REG_RED_SELECT, format->red.offset |
117 #ifdef CONFIG_DRM_HDLCD_SHOW_UNDERRUN
118 		    0x00ff0000 |	/* show underruns in red */
119 #endif
120 		    ((format->red.length & 0xf) << 8));
121 	hdlcd_write(hdlcd, HDLCD_REG_GREEN_SELECT, format->green.offset |
122 		    ((format->green.length & 0xf) << 8));
123 	hdlcd_write(hdlcd, HDLCD_REG_BLUE_SELECT, format->blue.offset |
124 		    ((format->blue.length & 0xf) << 8));
125 
126 	return 0;
127 }
128 
129 static void hdlcd_crtc_mode_set_nofb(struct drm_crtc *crtc)
130 {
131 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
132 	struct drm_display_mode *m = &crtc->state->adjusted_mode;
133 	struct videomode vm;
134 	unsigned int polarities, err;
135 
136 	vm.vfront_porch = m->crtc_vsync_start - m->crtc_vdisplay;
137 	vm.vback_porch = m->crtc_vtotal - m->crtc_vsync_end;
138 	vm.vsync_len = m->crtc_vsync_end - m->crtc_vsync_start;
139 	vm.hfront_porch = m->crtc_hsync_start - m->crtc_hdisplay;
140 	vm.hback_porch = m->crtc_htotal - m->crtc_hsync_end;
141 	vm.hsync_len = m->crtc_hsync_end - m->crtc_hsync_start;
142 
143 	polarities = HDLCD_POLARITY_DATAEN | HDLCD_POLARITY_DATA;
144 
145 	if (m->flags & DRM_MODE_FLAG_PHSYNC)
146 		polarities |= HDLCD_POLARITY_HSYNC;
147 	if (m->flags & DRM_MODE_FLAG_PVSYNC)
148 		polarities |= HDLCD_POLARITY_VSYNC;
149 
150 	/* Allow max number of outstanding requests and largest burst size */
151 	hdlcd_write(hdlcd, HDLCD_REG_BUS_OPTIONS,
152 		    HDLCD_BUS_MAX_OUTSTAND | HDLCD_BUS_BURST_16);
153 
154 	hdlcd_write(hdlcd, HDLCD_REG_V_DATA, m->crtc_vdisplay - 1);
155 	hdlcd_write(hdlcd, HDLCD_REG_V_BACK_PORCH, vm.vback_porch - 1);
156 	hdlcd_write(hdlcd, HDLCD_REG_V_FRONT_PORCH, vm.vfront_porch - 1);
157 	hdlcd_write(hdlcd, HDLCD_REG_V_SYNC, vm.vsync_len - 1);
158 	hdlcd_write(hdlcd, HDLCD_REG_H_DATA, m->crtc_hdisplay - 1);
159 	hdlcd_write(hdlcd, HDLCD_REG_H_BACK_PORCH, vm.hback_porch - 1);
160 	hdlcd_write(hdlcd, HDLCD_REG_H_FRONT_PORCH, vm.hfront_porch - 1);
161 	hdlcd_write(hdlcd, HDLCD_REG_H_SYNC, vm.hsync_len - 1);
162 	hdlcd_write(hdlcd, HDLCD_REG_POLARITIES, polarities);
163 
164 	err = hdlcd_set_pxl_fmt(crtc);
165 	if (err)
166 		return;
167 
168 	clk_set_rate(hdlcd->clk, m->crtc_clock * 1000);
169 }
170 
171 static void hdlcd_crtc_atomic_enable(struct drm_crtc *crtc,
172 				     struct drm_atomic_state *state)
173 {
174 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
175 
176 	clk_prepare_enable(hdlcd->clk);
177 	hdlcd_crtc_mode_set_nofb(crtc);
178 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 1);
179 	drm_crtc_vblank_on(crtc);
180 }
181 
182 static void hdlcd_crtc_atomic_disable(struct drm_crtc *crtc,
183 				      struct drm_atomic_state *state)
184 {
185 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
186 
187 	drm_crtc_vblank_off(crtc);
188 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
189 	clk_disable_unprepare(hdlcd->clk);
190 }
191 
192 static enum drm_mode_status hdlcd_crtc_mode_valid(struct drm_crtc *crtc,
193 		const struct drm_display_mode *mode)
194 {
195 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
196 	long rate, clk_rate = mode->clock * 1000;
197 
198 	rate = clk_round_rate(hdlcd->clk, clk_rate);
199 	/* 0.1% seems a close enough tolerance for the TDA19988 on Juno */
200 	if (abs(rate - clk_rate) * 1000 > clk_rate) {
201 		/* clock required by mode not supported by hardware */
202 		return MODE_NOCLOCK;
203 	}
204 
205 	return MODE_OK;
206 }
207 
208 static void hdlcd_crtc_atomic_begin(struct drm_crtc *crtc,
209 				    struct drm_atomic_state *state)
210 {
211 	struct drm_pending_vblank_event *event = crtc->state->event;
212 
213 	if (event) {
214 		crtc->state->event = NULL;
215 
216 		spin_lock_irq(&crtc->dev->event_lock);
217 		if (drm_crtc_vblank_get(crtc) == 0)
218 			drm_crtc_arm_vblank_event(crtc, event);
219 		else
220 			drm_crtc_send_vblank_event(crtc, event);
221 		spin_unlock_irq(&crtc->dev->event_lock);
222 	}
223 }
224 
225 static const struct drm_crtc_helper_funcs hdlcd_crtc_helper_funcs = {
226 	.mode_valid	= hdlcd_crtc_mode_valid,
227 	.atomic_begin	= hdlcd_crtc_atomic_begin,
228 	.atomic_enable	= hdlcd_crtc_atomic_enable,
229 	.atomic_disable	= hdlcd_crtc_atomic_disable,
230 };
231 
232 static int hdlcd_plane_atomic_check(struct drm_plane *plane,
233 				    struct drm_atomic_state *state)
234 {
235 	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state,
236 										 plane);
237 	int i;
238 	struct drm_crtc *crtc;
239 	struct drm_crtc_state *crtc_state;
240 	u32 src_h = new_plane_state->src_h >> 16;
241 
242 	/* only the HDLCD_REG_FB_LINE_COUNT register has a limit */
243 	if (src_h >= HDLCD_MAX_YRES) {
244 		DRM_DEBUG_KMS("Invalid source width: %d\n", src_h);
245 		return -EINVAL;
246 	}
247 
248 	for_each_new_crtc_in_state(state, crtc, crtc_state,
249 				   i) {
250 		/* we cannot disable the plane while the CRTC is active */
251 		if (!new_plane_state->fb && crtc_state->active)
252 			return -EINVAL;
253 		return drm_atomic_helper_check_plane_state(new_plane_state,
254 							   crtc_state,
255 							   DRM_PLANE_HELPER_NO_SCALING,
256 							   DRM_PLANE_HELPER_NO_SCALING,
257 							   false, true);
258 	}
259 
260 	return 0;
261 }
262 
263 static void hdlcd_plane_atomic_update(struct drm_plane *plane,
264 				      struct drm_atomic_state *state)
265 {
266 	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state,
267 										 plane);
268 	struct drm_framebuffer *fb = new_plane_state->fb;
269 	struct hdlcd_drm_private *hdlcd;
270 	u32 dest_h;
271 	dma_addr_t scanout_start;
272 
273 	if (!fb)
274 		return;
275 
276 	dest_h = drm_rect_height(&new_plane_state->dst);
277 	scanout_start = drm_fb_cma_get_gem_addr(fb, new_plane_state, 0);
278 
279 	hdlcd = plane->dev->dev_private;
280 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_LENGTH, fb->pitches[0]);
281 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_PITCH, fb->pitches[0]);
282 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_COUNT, dest_h - 1);
283 	hdlcd_write(hdlcd, HDLCD_REG_FB_BASE, scanout_start);
284 }
285 
286 static const struct drm_plane_helper_funcs hdlcd_plane_helper_funcs = {
287 	.atomic_check = hdlcd_plane_atomic_check,
288 	.atomic_update = hdlcd_plane_atomic_update,
289 };
290 
291 static const struct drm_plane_funcs hdlcd_plane_funcs = {
292 	.update_plane		= drm_atomic_helper_update_plane,
293 	.disable_plane		= drm_atomic_helper_disable_plane,
294 	.destroy		= drm_plane_cleanup,
295 	.reset			= drm_atomic_helper_plane_reset,
296 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
297 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
298 };
299 
300 static struct drm_plane *hdlcd_plane_init(struct drm_device *drm)
301 {
302 	struct hdlcd_drm_private *hdlcd = drm->dev_private;
303 	struct drm_plane *plane = NULL;
304 	u32 formats[ARRAY_SIZE(supported_formats)], i;
305 	int ret;
306 
307 	plane = devm_kzalloc(drm->dev, sizeof(*plane), GFP_KERNEL);
308 	if (!plane)
309 		return ERR_PTR(-ENOMEM);
310 
311 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++)
312 		formats[i] = supported_formats[i].fourcc;
313 
314 	ret = drm_universal_plane_init(drm, plane, 0xff, &hdlcd_plane_funcs,
315 				       formats, ARRAY_SIZE(formats),
316 				       NULL,
317 				       DRM_PLANE_TYPE_PRIMARY, NULL);
318 	if (ret)
319 		return ERR_PTR(ret);
320 
321 	drm_plane_helper_add(plane, &hdlcd_plane_helper_funcs);
322 	hdlcd->plane = plane;
323 
324 	return plane;
325 }
326 
327 int hdlcd_setup_crtc(struct drm_device *drm)
328 {
329 	struct hdlcd_drm_private *hdlcd = drm->dev_private;
330 	struct drm_plane *primary;
331 	int ret;
332 
333 	primary = hdlcd_plane_init(drm);
334 	if (IS_ERR(primary))
335 		return PTR_ERR(primary);
336 
337 	ret = drm_crtc_init_with_planes(drm, &hdlcd->crtc, primary, NULL,
338 					&hdlcd_crtc_funcs, NULL);
339 	if (ret)
340 		return ret;
341 
342 	drm_crtc_helper_add(&hdlcd->crtc, &hdlcd_crtc_helper_funcs);
343 	return 0;
344 }
345