xref: /openbmc/linux/drivers/gpu/drm/arm/hdlcd_crtc.c (revision 26b32974)
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_dma_helper.h>
22 #include <drm/drm_framebuffer.h>
23 #include <drm/drm_gem_dma_helper.h>
24 #include <drm/drm_of.h>
25 #include <drm/drm_probe_helper.h>
26 #include <drm/drm_vblank.h>
27 
28 #include "hdlcd_drv.h"
29 #include "hdlcd_regs.h"
30 
31 /*
32  * The HDLCD controller is a dumb RGB streamer that gets connected to
33  * a single HDMI transmitter or in the case of the ARM Models it gets
34  * emulated by the software that does the actual rendering.
35  *
36  */
37 
38 static void hdlcd_crtc_cleanup(struct drm_crtc *crtc)
39 {
40 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
41 
42 	/* stop the controller on cleanup */
43 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
44 	drm_crtc_cleanup(crtc);
45 }
46 
47 static int hdlcd_crtc_enable_vblank(struct drm_crtc *crtc)
48 {
49 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
50 	unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
51 
52 	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask | HDLCD_INTERRUPT_VSYNC);
53 
54 	return 0;
55 }
56 
57 static void hdlcd_crtc_disable_vblank(struct drm_crtc *crtc)
58 {
59 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
60 	unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
61 
62 	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask & ~HDLCD_INTERRUPT_VSYNC);
63 }
64 
65 static const struct drm_crtc_funcs hdlcd_crtc_funcs = {
66 	.destroy = hdlcd_crtc_cleanup,
67 	.set_config = drm_atomic_helper_set_config,
68 	.page_flip = drm_atomic_helper_page_flip,
69 	.reset = drm_atomic_helper_crtc_reset,
70 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
71 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
72 	.enable_vblank = hdlcd_crtc_enable_vblank,
73 	.disable_vblank = hdlcd_crtc_disable_vblank,
74 };
75 
76 static struct simplefb_format supported_formats[] = SIMPLEFB_FORMATS;
77 
78 /*
79  * Setup the HDLCD registers for decoding the pixels out of the framebuffer
80  */
81 static int hdlcd_set_pxl_fmt(struct drm_crtc *crtc)
82 {
83 	unsigned int btpp;
84 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
85 	const struct drm_framebuffer *fb = crtc->primary->state->fb;
86 	uint32_t pixel_format;
87 	struct simplefb_format *format = NULL;
88 	int i;
89 
90 	pixel_format = fb->format->format;
91 
92 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++) {
93 		if (supported_formats[i].fourcc == pixel_format)
94 			format = &supported_formats[i];
95 	}
96 
97 	if (WARN_ON(!format))
98 		return 0;
99 
100 	/* HDLCD uses 'bytes per pixel', zero means 1 byte */
101 	btpp = (format->bits_per_pixel + 7) / 8;
102 	hdlcd_write(hdlcd, HDLCD_REG_PIXEL_FORMAT, (btpp - 1) << 3);
103 
104 	/*
105 	 * The format of the HDLCD_REG_<color>_SELECT register is:
106 	 *   - bits[23:16] - default value for that color component
107 	 *   - bits[11:8]  - number of bits to extract for each color component
108 	 *   - bits[4:0]   - index of the lowest bit to extract
109 	 *
110 	 * The default color value is used when bits[11:8] are zero, when the
111 	 * pixel is outside the visible frame area or when there is a
112 	 * buffer underrun.
113 	 */
114 	hdlcd_write(hdlcd, HDLCD_REG_RED_SELECT, format->red.offset |
115 #ifdef CONFIG_DRM_HDLCD_SHOW_UNDERRUN
116 		    0x00ff0000 |	/* show underruns in red */
117 #endif
118 		    ((format->red.length & 0xf) << 8));
119 	hdlcd_write(hdlcd, HDLCD_REG_GREEN_SELECT, format->green.offset |
120 		    ((format->green.length & 0xf) << 8));
121 	hdlcd_write(hdlcd, HDLCD_REG_BLUE_SELECT, format->blue.offset |
122 		    ((format->blue.length & 0xf) << 8));
123 
124 	return 0;
125 }
126 
127 static void hdlcd_crtc_mode_set_nofb(struct drm_crtc *crtc)
128 {
129 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
130 	struct drm_display_mode *m = &crtc->state->adjusted_mode;
131 	struct videomode vm;
132 	unsigned int polarities, err;
133 
134 	vm.vfront_porch = m->crtc_vsync_start - m->crtc_vdisplay;
135 	vm.vback_porch = m->crtc_vtotal - m->crtc_vsync_end;
136 	vm.vsync_len = m->crtc_vsync_end - m->crtc_vsync_start;
137 	vm.hfront_porch = m->crtc_hsync_start - m->crtc_hdisplay;
138 	vm.hback_porch = m->crtc_htotal - m->crtc_hsync_end;
139 	vm.hsync_len = m->crtc_hsync_end - m->crtc_hsync_start;
140 
141 	polarities = HDLCD_POLARITY_DATAEN | HDLCD_POLARITY_DATA;
142 
143 	if (m->flags & DRM_MODE_FLAG_PHSYNC)
144 		polarities |= HDLCD_POLARITY_HSYNC;
145 	if (m->flags & DRM_MODE_FLAG_PVSYNC)
146 		polarities |= HDLCD_POLARITY_VSYNC;
147 
148 	/* Allow max number of outstanding requests and largest burst size */
149 	hdlcd_write(hdlcd, HDLCD_REG_BUS_OPTIONS,
150 		    HDLCD_BUS_MAX_OUTSTAND | HDLCD_BUS_BURST_16);
151 
152 	hdlcd_write(hdlcd, HDLCD_REG_V_DATA, m->crtc_vdisplay - 1);
153 	hdlcd_write(hdlcd, HDLCD_REG_V_BACK_PORCH, vm.vback_porch - 1);
154 	hdlcd_write(hdlcd, HDLCD_REG_V_FRONT_PORCH, vm.vfront_porch - 1);
155 	hdlcd_write(hdlcd, HDLCD_REG_V_SYNC, vm.vsync_len - 1);
156 	hdlcd_write(hdlcd, HDLCD_REG_H_DATA, m->crtc_hdisplay - 1);
157 	hdlcd_write(hdlcd, HDLCD_REG_H_BACK_PORCH, vm.hback_porch - 1);
158 	hdlcd_write(hdlcd, HDLCD_REG_H_FRONT_PORCH, vm.hfront_porch - 1);
159 	hdlcd_write(hdlcd, HDLCD_REG_H_SYNC, vm.hsync_len - 1);
160 	hdlcd_write(hdlcd, HDLCD_REG_POLARITIES, polarities);
161 
162 	err = hdlcd_set_pxl_fmt(crtc);
163 	if (err)
164 		return;
165 
166 	clk_set_rate(hdlcd->clk, m->crtc_clock * 1000);
167 }
168 
169 static void hdlcd_crtc_atomic_enable(struct drm_crtc *crtc,
170 				     struct drm_atomic_state *state)
171 {
172 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
173 
174 	clk_prepare_enable(hdlcd->clk);
175 	hdlcd_crtc_mode_set_nofb(crtc);
176 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 1);
177 	drm_crtc_vblank_on(crtc);
178 }
179 
180 static void hdlcd_crtc_atomic_disable(struct drm_crtc *crtc,
181 				      struct drm_atomic_state *state)
182 {
183 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
184 
185 	drm_crtc_vblank_off(crtc);
186 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
187 	clk_disable_unprepare(hdlcd->clk);
188 }
189 
190 static enum drm_mode_status hdlcd_crtc_mode_valid(struct drm_crtc *crtc,
191 		const struct drm_display_mode *mode)
192 {
193 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
194 	long rate, clk_rate = mode->clock * 1000;
195 
196 	rate = clk_round_rate(hdlcd->clk, clk_rate);
197 	/* 0.1% seems a close enough tolerance for the TDA19988 on Juno */
198 	if (abs(rate - clk_rate) * 1000 > clk_rate) {
199 		/* clock required by mode not supported by hardware */
200 		return MODE_NOCLOCK;
201 	}
202 
203 	return MODE_OK;
204 }
205 
206 static void hdlcd_crtc_atomic_begin(struct drm_crtc *crtc,
207 				    struct drm_atomic_state *state)
208 {
209 	struct drm_pending_vblank_event *event = crtc->state->event;
210 
211 	if (event) {
212 		crtc->state->event = NULL;
213 
214 		spin_lock_irq(&crtc->dev->event_lock);
215 		if (drm_crtc_vblank_get(crtc) == 0)
216 			drm_crtc_arm_vblank_event(crtc, event);
217 		else
218 			drm_crtc_send_vblank_event(crtc, event);
219 		spin_unlock_irq(&crtc->dev->event_lock);
220 	}
221 }
222 
223 static const struct drm_crtc_helper_funcs hdlcd_crtc_helper_funcs = {
224 	.mode_valid	= hdlcd_crtc_mode_valid,
225 	.atomic_begin	= hdlcd_crtc_atomic_begin,
226 	.atomic_enable	= hdlcd_crtc_atomic_enable,
227 	.atomic_disable	= hdlcd_crtc_atomic_disable,
228 };
229 
230 static int hdlcd_plane_atomic_check(struct drm_plane *plane,
231 				    struct drm_atomic_state *state)
232 {
233 	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state,
234 										 plane);
235 	int i;
236 	struct drm_crtc *crtc;
237 	struct drm_crtc_state *crtc_state;
238 	u32 src_h = new_plane_state->src_h >> 16;
239 
240 	/* only the HDLCD_REG_FB_LINE_COUNT register has a limit */
241 	if (src_h >= HDLCD_MAX_YRES) {
242 		DRM_DEBUG_KMS("Invalid source width: %d\n", src_h);
243 		return -EINVAL;
244 	}
245 
246 	for_each_new_crtc_in_state(state, crtc, crtc_state,
247 				   i) {
248 		/* we cannot disable the plane while the CRTC is active */
249 		if (!new_plane_state->fb && crtc_state->active)
250 			return -EINVAL;
251 		return drm_atomic_helper_check_plane_state(new_plane_state,
252 							   crtc_state,
253 							   DRM_PLANE_NO_SCALING,
254 							   DRM_PLANE_NO_SCALING,
255 							   false, true);
256 	}
257 
258 	return 0;
259 }
260 
261 static void hdlcd_plane_atomic_update(struct drm_plane *plane,
262 				      struct drm_atomic_state *state)
263 {
264 	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state,
265 										 plane);
266 	struct drm_framebuffer *fb = new_plane_state->fb;
267 	struct hdlcd_drm_private *hdlcd;
268 	u32 dest_h;
269 	dma_addr_t scanout_start;
270 
271 	if (!fb)
272 		return;
273 
274 	dest_h = drm_rect_height(&new_plane_state->dst);
275 	scanout_start = drm_fb_dma_get_gem_addr(fb, new_plane_state, 0);
276 
277 	hdlcd = drm_to_hdlcd_priv(plane->dev);
278 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_LENGTH, fb->pitches[0]);
279 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_PITCH, fb->pitches[0]);
280 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_COUNT, dest_h - 1);
281 	hdlcd_write(hdlcd, HDLCD_REG_FB_BASE, scanout_start);
282 }
283 
284 static const struct drm_plane_helper_funcs hdlcd_plane_helper_funcs = {
285 	.atomic_check = hdlcd_plane_atomic_check,
286 	.atomic_update = hdlcd_plane_atomic_update,
287 };
288 
289 static const struct drm_plane_funcs hdlcd_plane_funcs = {
290 	.update_plane		= drm_atomic_helper_update_plane,
291 	.disable_plane		= drm_atomic_helper_disable_plane,
292 	.reset			= drm_atomic_helper_plane_reset,
293 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
294 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
295 };
296 
297 static struct drm_plane *hdlcd_plane_init(struct drm_device *drm)
298 {
299 	struct hdlcd_drm_private *hdlcd = drm_to_hdlcd_priv(drm);
300 	struct drm_plane *plane = NULL;
301 	u32 formats[ARRAY_SIZE(supported_formats)], i;
302 
303 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++)
304 		formats[i] = supported_formats[i].fourcc;
305 
306 	plane = drmm_universal_plane_alloc(drm, struct drm_plane, dev, 0xff,
307 					   &hdlcd_plane_funcs,
308 					   formats, ARRAY_SIZE(formats),
309 					   NULL, DRM_PLANE_TYPE_PRIMARY, NULL);
310 	if (IS_ERR(plane))
311 		return plane;
312 
313 	drm_plane_helper_add(plane, &hdlcd_plane_helper_funcs);
314 	hdlcd->plane = plane;
315 
316 	return plane;
317 }
318 
319 int hdlcd_setup_crtc(struct drm_device *drm)
320 {
321 	struct hdlcd_drm_private *hdlcd = drm_to_hdlcd_priv(drm);
322 	struct drm_plane *primary;
323 	int ret;
324 
325 	primary = hdlcd_plane_init(drm);
326 	if (IS_ERR(primary))
327 		return PTR_ERR(primary);
328 
329 	ret = drm_crtc_init_with_planes(drm, &hdlcd->crtc, primary, NULL,
330 					&hdlcd_crtc_funcs, NULL);
331 	if (ret)
332 		return ret;
333 
334 	drm_crtc_helper_add(&hdlcd->crtc, &hdlcd_crtc_helper_funcs);
335 	return 0;
336 }
337