xref: /openbmc/linux/drivers/gpu/drm/arm/hdlcd_crtc.c (revision 50df3be7)
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_gem_cma_helper.h>
24 #include <drm/drm_of.h>
25 #include <drm/drm_plane_helper.h>
26 #include <drm/drm_probe_helper.h>
27 #include <drm/drm_vblank.h>
28 
29 #include "hdlcd_drv.h"
30 #include "hdlcd_regs.h"
31 
32 /*
33  * The HDLCD controller is a dumb RGB streamer that gets connected to
34  * a single HDMI transmitter or in the case of the ARM Models it gets
35  * emulated by the software that does the actual rendering.
36  *
37  */
38 
39 static void hdlcd_crtc_cleanup(struct drm_crtc *crtc)
40 {
41 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
42 
43 	/* stop the controller on cleanup */
44 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
45 	drm_crtc_cleanup(crtc);
46 }
47 
48 static int hdlcd_crtc_enable_vblank(struct drm_crtc *crtc)
49 {
50 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
51 	unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
52 
53 	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask | HDLCD_INTERRUPT_VSYNC);
54 
55 	return 0;
56 }
57 
58 static void hdlcd_crtc_disable_vblank(struct drm_crtc *crtc)
59 {
60 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
61 	unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
62 
63 	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask & ~HDLCD_INTERRUPT_VSYNC);
64 }
65 
66 static const struct drm_crtc_funcs hdlcd_crtc_funcs = {
67 	.destroy = hdlcd_crtc_cleanup,
68 	.set_config = drm_atomic_helper_set_config,
69 	.page_flip = drm_atomic_helper_page_flip,
70 	.reset = drm_atomic_helper_crtc_reset,
71 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
72 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
73 	.enable_vblank = hdlcd_crtc_enable_vblank,
74 	.disable_vblank = hdlcd_crtc_disable_vblank,
75 };
76 
77 static struct simplefb_format supported_formats[] = SIMPLEFB_FORMATS;
78 
79 /*
80  * Setup the HDLCD registers for decoding the pixels out of the framebuffer
81  */
82 static int hdlcd_set_pxl_fmt(struct drm_crtc *crtc)
83 {
84 	unsigned int btpp;
85 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
86 	const struct drm_framebuffer *fb = crtc->primary->state->fb;
87 	uint32_t pixel_format;
88 	struct simplefb_format *format = NULL;
89 	int i;
90 
91 	pixel_format = fb->format->format;
92 
93 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++) {
94 		if (supported_formats[i].fourcc == pixel_format)
95 			format = &supported_formats[i];
96 	}
97 
98 	if (WARN_ON(!format))
99 		return 0;
100 
101 	/* HDLCD uses 'bytes per pixel', zero means 1 byte */
102 	btpp = (format->bits_per_pixel + 7) / 8;
103 	hdlcd_write(hdlcd, HDLCD_REG_PIXEL_FORMAT, (btpp - 1) << 3);
104 
105 	/*
106 	 * The format of the HDLCD_REG_<color>_SELECT register is:
107 	 *   - bits[23:16] - default value for that color component
108 	 *   - bits[11:8]  - number of bits to extract for each color component
109 	 *   - bits[4:0]   - index of the lowest bit to extract
110 	 *
111 	 * The default color value is used when bits[11:8] are zero, when the
112 	 * pixel is outside the visible frame area or when there is a
113 	 * buffer underrun.
114 	 */
115 	hdlcd_write(hdlcd, HDLCD_REG_RED_SELECT, format->red.offset |
116 #ifdef CONFIG_DRM_HDLCD_SHOW_UNDERRUN
117 		    0x00ff0000 |	/* show underruns in red */
118 #endif
119 		    ((format->red.length & 0xf) << 8));
120 	hdlcd_write(hdlcd, HDLCD_REG_GREEN_SELECT, format->green.offset |
121 		    ((format->green.length & 0xf) << 8));
122 	hdlcd_write(hdlcd, HDLCD_REG_BLUE_SELECT, format->blue.offset |
123 		    ((format->blue.length & 0xf) << 8));
124 
125 	return 0;
126 }
127 
128 static void hdlcd_crtc_mode_set_nofb(struct drm_crtc *crtc)
129 {
130 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
131 	struct drm_display_mode *m = &crtc->state->adjusted_mode;
132 	struct videomode vm;
133 	unsigned int polarities, err;
134 
135 	vm.vfront_porch = m->crtc_vsync_start - m->crtc_vdisplay;
136 	vm.vback_porch = m->crtc_vtotal - m->crtc_vsync_end;
137 	vm.vsync_len = m->crtc_vsync_end - m->crtc_vsync_start;
138 	vm.hfront_porch = m->crtc_hsync_start - m->crtc_hdisplay;
139 	vm.hback_porch = m->crtc_htotal - m->crtc_hsync_end;
140 	vm.hsync_len = m->crtc_hsync_end - m->crtc_hsync_start;
141 
142 	polarities = HDLCD_POLARITY_DATAEN | HDLCD_POLARITY_DATA;
143 
144 	if (m->flags & DRM_MODE_FLAG_PHSYNC)
145 		polarities |= HDLCD_POLARITY_HSYNC;
146 	if (m->flags & DRM_MODE_FLAG_PVSYNC)
147 		polarities |= HDLCD_POLARITY_VSYNC;
148 
149 	/* Allow max number of outstanding requests and largest burst size */
150 	hdlcd_write(hdlcd, HDLCD_REG_BUS_OPTIONS,
151 		    HDLCD_BUS_MAX_OUTSTAND | HDLCD_BUS_BURST_16);
152 
153 	hdlcd_write(hdlcd, HDLCD_REG_V_DATA, m->crtc_vdisplay - 1);
154 	hdlcd_write(hdlcd, HDLCD_REG_V_BACK_PORCH, vm.vback_porch - 1);
155 	hdlcd_write(hdlcd, HDLCD_REG_V_FRONT_PORCH, vm.vfront_porch - 1);
156 	hdlcd_write(hdlcd, HDLCD_REG_V_SYNC, vm.vsync_len - 1);
157 	hdlcd_write(hdlcd, HDLCD_REG_H_DATA, m->crtc_hdisplay - 1);
158 	hdlcd_write(hdlcd, HDLCD_REG_H_BACK_PORCH, vm.hback_porch - 1);
159 	hdlcd_write(hdlcd, HDLCD_REG_H_FRONT_PORCH, vm.hfront_porch - 1);
160 	hdlcd_write(hdlcd, HDLCD_REG_H_SYNC, vm.hsync_len - 1);
161 	hdlcd_write(hdlcd, HDLCD_REG_POLARITIES, polarities);
162 
163 	err = hdlcd_set_pxl_fmt(crtc);
164 	if (err)
165 		return;
166 
167 	clk_set_rate(hdlcd->clk, m->crtc_clock * 1000);
168 }
169 
170 static void hdlcd_crtc_atomic_enable(struct drm_crtc *crtc,
171 				     struct drm_crtc_state *old_state)
172 {
173 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
174 
175 	clk_prepare_enable(hdlcd->clk);
176 	hdlcd_crtc_mode_set_nofb(crtc);
177 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 1);
178 	drm_crtc_vblank_on(crtc);
179 }
180 
181 static void hdlcd_crtc_atomic_disable(struct drm_crtc *crtc,
182 				      struct drm_crtc_state *old_state)
183 {
184 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
185 
186 	drm_crtc_vblank_off(crtc);
187 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
188 	clk_disable_unprepare(hdlcd->clk);
189 }
190 
191 static enum drm_mode_status hdlcd_crtc_mode_valid(struct drm_crtc *crtc,
192 		const struct drm_display_mode *mode)
193 {
194 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
195 	long rate, clk_rate = mode->clock * 1000;
196 
197 	rate = clk_round_rate(hdlcd->clk, clk_rate);
198 	/* 0.1% seems a close enough tolerance for the TDA19988 on Juno */
199 	if (abs(rate - clk_rate) * 1000 > clk_rate) {
200 		/* clock required by mode not supported by hardware */
201 		return MODE_NOCLOCK;
202 	}
203 
204 	return MODE_OK;
205 }
206 
207 static void hdlcd_crtc_atomic_begin(struct drm_crtc *crtc,
208 				    struct drm_crtc_state *state)
209 {
210 	struct drm_pending_vblank_event *event = crtc->state->event;
211 
212 	if (event) {
213 		crtc->state->event = NULL;
214 
215 		spin_lock_irq(&crtc->dev->event_lock);
216 		if (drm_crtc_vblank_get(crtc) == 0)
217 			drm_crtc_arm_vblank_event(crtc, event);
218 		else
219 			drm_crtc_send_vblank_event(crtc, event);
220 		spin_unlock_irq(&crtc->dev->event_lock);
221 	}
222 }
223 
224 static const struct drm_crtc_helper_funcs hdlcd_crtc_helper_funcs = {
225 	.mode_valid	= hdlcd_crtc_mode_valid,
226 	.atomic_begin	= hdlcd_crtc_atomic_begin,
227 	.atomic_enable	= hdlcd_crtc_atomic_enable,
228 	.atomic_disable	= hdlcd_crtc_atomic_disable,
229 };
230 
231 static int hdlcd_plane_atomic_check(struct drm_plane *plane,
232 				    struct drm_plane_state *state)
233 {
234 	int i;
235 	struct drm_crtc *crtc;
236 	struct drm_crtc_state *crtc_state;
237 	u32 src_h = state->src_h >> 16;
238 
239 	/* only the HDLCD_REG_FB_LINE_COUNT register has a limit */
240 	if (src_h >= HDLCD_MAX_YRES) {
241 		DRM_DEBUG_KMS("Invalid source width: %d\n", src_h);
242 		return -EINVAL;
243 	}
244 
245 	for_each_new_crtc_in_state(state->state, crtc, crtc_state, i) {
246 		/* we cannot disable the plane while the CRTC is active */
247 		if (!state->fb && crtc_state->active)
248 			return -EINVAL;
249 		return drm_atomic_helper_check_plane_state(state, crtc_state,
250 						DRM_PLANE_HELPER_NO_SCALING,
251 						DRM_PLANE_HELPER_NO_SCALING,
252 						false, true);
253 	}
254 
255 	return 0;
256 }
257 
258 static void hdlcd_plane_atomic_update(struct drm_plane *plane,
259 				      struct drm_plane_state *state)
260 {
261 	struct drm_framebuffer *fb = plane->state->fb;
262 	struct hdlcd_drm_private *hdlcd;
263 	u32 dest_h;
264 	dma_addr_t scanout_start;
265 
266 	if (!fb)
267 		return;
268 
269 	dest_h = drm_rect_height(&plane->state->dst);
270 	scanout_start = drm_fb_cma_get_gem_addr(fb, plane->state, 0);
271 
272 	hdlcd = plane->dev->dev_private;
273 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_LENGTH, fb->pitches[0]);
274 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_PITCH, fb->pitches[0]);
275 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_COUNT, dest_h - 1);
276 	hdlcd_write(hdlcd, HDLCD_REG_FB_BASE, scanout_start);
277 }
278 
279 static const struct drm_plane_helper_funcs hdlcd_plane_helper_funcs = {
280 	.atomic_check = hdlcd_plane_atomic_check,
281 	.atomic_update = hdlcd_plane_atomic_update,
282 };
283 
284 static const struct drm_plane_funcs hdlcd_plane_funcs = {
285 	.update_plane		= drm_atomic_helper_update_plane,
286 	.disable_plane		= drm_atomic_helper_disable_plane,
287 	.destroy		= drm_plane_cleanup,
288 	.reset			= drm_atomic_helper_plane_reset,
289 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
290 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
291 };
292 
293 static struct drm_plane *hdlcd_plane_init(struct drm_device *drm)
294 {
295 	struct hdlcd_drm_private *hdlcd = drm->dev_private;
296 	struct drm_plane *plane = NULL;
297 	u32 formats[ARRAY_SIZE(supported_formats)], i;
298 	int ret;
299 
300 	plane = devm_kzalloc(drm->dev, sizeof(*plane), GFP_KERNEL);
301 	if (!plane)
302 		return ERR_PTR(-ENOMEM);
303 
304 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++)
305 		formats[i] = supported_formats[i].fourcc;
306 
307 	ret = drm_universal_plane_init(drm, plane, 0xff, &hdlcd_plane_funcs,
308 				       formats, ARRAY_SIZE(formats),
309 				       NULL,
310 				       DRM_PLANE_TYPE_PRIMARY, NULL);
311 	if (ret)
312 		return ERR_PTR(ret);
313 
314 	drm_plane_helper_add(plane, &hdlcd_plane_helper_funcs);
315 	hdlcd->plane = plane;
316 
317 	return plane;
318 }
319 
320 int hdlcd_setup_crtc(struct drm_device *drm)
321 {
322 	struct hdlcd_drm_private *hdlcd = drm->dev_private;
323 	struct drm_plane *primary;
324 	int ret;
325 
326 	primary = hdlcd_plane_init(drm);
327 	if (IS_ERR(primary))
328 		return PTR_ERR(primary);
329 
330 	ret = drm_crtc_init_with_planes(drm, &hdlcd->crtc, primary, NULL,
331 					&hdlcd_crtc_funcs, NULL);
332 	if (ret)
333 		return ret;
334 
335 	drm_crtc_helper_add(&hdlcd->crtc, &hdlcd_crtc_helper_funcs);
336 	return 0;
337 }
338