xref: /openbmc/linux/drivers/gpu/drm/arm/hdlcd_crtc.c (revision b830f94f)
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.h>
14 #include <drm/drm_atomic_helper.h>
15 #include <drm/drm_crtc.h>
16 #include <drm/drm_fb_cma_helper.h>
17 #include <drm/drm_fb_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 <drm/drm_probe_helper.h>
22 #include <linux/clk.h>
23 #include <linux/of_graph.h>
24 #include <linux/platform_data/simplefb.h>
25 #include <video/videomode.h>
26 
27 #include "hdlcd_drv.h"
28 #include "hdlcd_regs.h"
29 
30 /*
31  * The HDLCD controller is a dumb RGB streamer that gets connected to
32  * a single HDMI transmitter or in the case of the ARM Models it gets
33  * emulated by the software that does the actual rendering.
34  *
35  */
36 
37 static void hdlcd_crtc_cleanup(struct drm_crtc *crtc)
38 {
39 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
40 
41 	/* stop the controller on cleanup */
42 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
43 	drm_crtc_cleanup(crtc);
44 }
45 
46 static int hdlcd_crtc_enable_vblank(struct drm_crtc *crtc)
47 {
48 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
49 	unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
50 
51 	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask | HDLCD_INTERRUPT_VSYNC);
52 
53 	return 0;
54 }
55 
56 static void hdlcd_crtc_disable_vblank(struct drm_crtc *crtc)
57 {
58 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
59 	unsigned int mask = hdlcd_read(hdlcd, HDLCD_REG_INT_MASK);
60 
61 	hdlcd_write(hdlcd, HDLCD_REG_INT_MASK, mask & ~HDLCD_INTERRUPT_VSYNC);
62 }
63 
64 static const struct drm_crtc_funcs hdlcd_crtc_funcs = {
65 	.destroy = hdlcd_crtc_cleanup,
66 	.set_config = drm_atomic_helper_set_config,
67 	.page_flip = drm_atomic_helper_page_flip,
68 	.reset = drm_atomic_helper_crtc_reset,
69 	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
70 	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
71 	.enable_vblank = hdlcd_crtc_enable_vblank,
72 	.disable_vblank = hdlcd_crtc_disable_vblank,
73 };
74 
75 static struct simplefb_format supported_formats[] = SIMPLEFB_FORMATS;
76 
77 /*
78  * Setup the HDLCD registers for decoding the pixels out of the framebuffer
79  */
80 static int hdlcd_set_pxl_fmt(struct drm_crtc *crtc)
81 {
82 	unsigned int btpp;
83 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
84 	const struct drm_framebuffer *fb = crtc->primary->state->fb;
85 	uint32_t pixel_format;
86 	struct simplefb_format *format = NULL;
87 	int i;
88 
89 	pixel_format = fb->format->format;
90 
91 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++) {
92 		if (supported_formats[i].fourcc == pixel_format)
93 			format = &supported_formats[i];
94 	}
95 
96 	if (WARN_ON(!format))
97 		return 0;
98 
99 	/* HDLCD uses 'bytes per pixel', zero means 1 byte */
100 	btpp = (format->bits_per_pixel + 7) / 8;
101 	hdlcd_write(hdlcd, HDLCD_REG_PIXEL_FORMAT, (btpp - 1) << 3);
102 
103 	/*
104 	 * The format of the HDLCD_REG_<color>_SELECT register is:
105 	 *   - bits[23:16] - default value for that color component
106 	 *   - bits[11:8]  - number of bits to extract for each color component
107 	 *   - bits[4:0]   - index of the lowest bit to extract
108 	 *
109 	 * The default color value is used when bits[11:8] are zero, when the
110 	 * pixel is outside the visible frame area or when there is a
111 	 * buffer underrun.
112 	 */
113 	hdlcd_write(hdlcd, HDLCD_REG_RED_SELECT, format->red.offset |
114 #ifdef CONFIG_DRM_HDLCD_SHOW_UNDERRUN
115 		    0x00ff0000 |	/* show underruns in red */
116 #endif
117 		    ((format->red.length & 0xf) << 8));
118 	hdlcd_write(hdlcd, HDLCD_REG_GREEN_SELECT, format->green.offset |
119 		    ((format->green.length & 0xf) << 8));
120 	hdlcd_write(hdlcd, HDLCD_REG_BLUE_SELECT, format->blue.offset |
121 		    ((format->blue.length & 0xf) << 8));
122 
123 	return 0;
124 }
125 
126 static void hdlcd_crtc_mode_set_nofb(struct drm_crtc *crtc)
127 {
128 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
129 	struct drm_display_mode *m = &crtc->state->adjusted_mode;
130 	struct videomode vm;
131 	unsigned int polarities, err;
132 
133 	vm.vfront_porch = m->crtc_vsync_start - m->crtc_vdisplay;
134 	vm.vback_porch = m->crtc_vtotal - m->crtc_vsync_end;
135 	vm.vsync_len = m->crtc_vsync_end - m->crtc_vsync_start;
136 	vm.hfront_porch = m->crtc_hsync_start - m->crtc_hdisplay;
137 	vm.hback_porch = m->crtc_htotal - m->crtc_hsync_end;
138 	vm.hsync_len = m->crtc_hsync_end - m->crtc_hsync_start;
139 
140 	polarities = HDLCD_POLARITY_DATAEN | HDLCD_POLARITY_DATA;
141 
142 	if (m->flags & DRM_MODE_FLAG_PHSYNC)
143 		polarities |= HDLCD_POLARITY_HSYNC;
144 	if (m->flags & DRM_MODE_FLAG_PVSYNC)
145 		polarities |= HDLCD_POLARITY_VSYNC;
146 
147 	/* Allow max number of outstanding requests and largest burst size */
148 	hdlcd_write(hdlcd, HDLCD_REG_BUS_OPTIONS,
149 		    HDLCD_BUS_MAX_OUTSTAND | HDLCD_BUS_BURST_16);
150 
151 	hdlcd_write(hdlcd, HDLCD_REG_V_DATA, m->crtc_vdisplay - 1);
152 	hdlcd_write(hdlcd, HDLCD_REG_V_BACK_PORCH, vm.vback_porch - 1);
153 	hdlcd_write(hdlcd, HDLCD_REG_V_FRONT_PORCH, vm.vfront_porch - 1);
154 	hdlcd_write(hdlcd, HDLCD_REG_V_SYNC, vm.vsync_len - 1);
155 	hdlcd_write(hdlcd, HDLCD_REG_H_DATA, m->crtc_hdisplay - 1);
156 	hdlcd_write(hdlcd, HDLCD_REG_H_BACK_PORCH, vm.hback_porch - 1);
157 	hdlcd_write(hdlcd, HDLCD_REG_H_FRONT_PORCH, vm.hfront_porch - 1);
158 	hdlcd_write(hdlcd, HDLCD_REG_H_SYNC, vm.hsync_len - 1);
159 	hdlcd_write(hdlcd, HDLCD_REG_POLARITIES, polarities);
160 
161 	err = hdlcd_set_pxl_fmt(crtc);
162 	if (err)
163 		return;
164 
165 	clk_set_rate(hdlcd->clk, m->crtc_clock * 1000);
166 }
167 
168 static void hdlcd_crtc_atomic_enable(struct drm_crtc *crtc,
169 				     struct drm_crtc_state *old_state)
170 {
171 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
172 
173 	clk_prepare_enable(hdlcd->clk);
174 	hdlcd_crtc_mode_set_nofb(crtc);
175 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 1);
176 	drm_crtc_vblank_on(crtc);
177 }
178 
179 static void hdlcd_crtc_atomic_disable(struct drm_crtc *crtc,
180 				      struct drm_crtc_state *old_state)
181 {
182 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
183 
184 	drm_crtc_vblank_off(crtc);
185 	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
186 	clk_disable_unprepare(hdlcd->clk);
187 }
188 
189 static enum drm_mode_status hdlcd_crtc_mode_valid(struct drm_crtc *crtc,
190 		const struct drm_display_mode *mode)
191 {
192 	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
193 	long rate, clk_rate = mode->clock * 1000;
194 
195 	rate = clk_round_rate(hdlcd->clk, clk_rate);
196 	/* 0.1% seems a close enough tolerance for the TDA19988 on Juno */
197 	if (abs(rate - clk_rate) * 1000 > clk_rate) {
198 		/* clock required by mode not supported by hardware */
199 		return MODE_NOCLOCK;
200 	}
201 
202 	return MODE_OK;
203 }
204 
205 static void hdlcd_crtc_atomic_begin(struct drm_crtc *crtc,
206 				    struct drm_crtc_state *state)
207 {
208 	struct drm_pending_vblank_event *event = crtc->state->event;
209 
210 	if (event) {
211 		crtc->state->event = NULL;
212 
213 		spin_lock_irq(&crtc->dev->event_lock);
214 		if (drm_crtc_vblank_get(crtc) == 0)
215 			drm_crtc_arm_vblank_event(crtc, event);
216 		else
217 			drm_crtc_send_vblank_event(crtc, event);
218 		spin_unlock_irq(&crtc->dev->event_lock);
219 	}
220 }
221 
222 static const struct drm_crtc_helper_funcs hdlcd_crtc_helper_funcs = {
223 	.mode_valid	= hdlcd_crtc_mode_valid,
224 	.atomic_begin	= hdlcd_crtc_atomic_begin,
225 	.atomic_enable	= hdlcd_crtc_atomic_enable,
226 	.atomic_disable	= hdlcd_crtc_atomic_disable,
227 };
228 
229 static int hdlcd_plane_atomic_check(struct drm_plane *plane,
230 				    struct drm_plane_state *state)
231 {
232 	int i;
233 	struct drm_crtc *crtc;
234 	struct drm_crtc_state *crtc_state;
235 	u32 src_h = state->src_h >> 16;
236 
237 	/* only the HDLCD_REG_FB_LINE_COUNT register has a limit */
238 	if (src_h >= HDLCD_MAX_YRES) {
239 		DRM_DEBUG_KMS("Invalid source width: %d\n", src_h);
240 		return -EINVAL;
241 	}
242 
243 	for_each_new_crtc_in_state(state->state, crtc, crtc_state, i) {
244 		/* we cannot disable the plane while the CRTC is active */
245 		if (!state->fb && crtc_state->active)
246 			return -EINVAL;
247 		return drm_atomic_helper_check_plane_state(state, crtc_state,
248 						DRM_PLANE_HELPER_NO_SCALING,
249 						DRM_PLANE_HELPER_NO_SCALING,
250 						false, true);
251 	}
252 
253 	return 0;
254 }
255 
256 static void hdlcd_plane_atomic_update(struct drm_plane *plane,
257 				      struct drm_plane_state *state)
258 {
259 	struct drm_framebuffer *fb = plane->state->fb;
260 	struct hdlcd_drm_private *hdlcd;
261 	u32 dest_h;
262 	dma_addr_t scanout_start;
263 
264 	if (!fb)
265 		return;
266 
267 	dest_h = drm_rect_height(&plane->state->dst);
268 	scanout_start = drm_fb_cma_get_gem_addr(fb, plane->state, 0);
269 
270 	hdlcd = plane->dev->dev_private;
271 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_LENGTH, fb->pitches[0]);
272 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_PITCH, fb->pitches[0]);
273 	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_COUNT, dest_h - 1);
274 	hdlcd_write(hdlcd, HDLCD_REG_FB_BASE, scanout_start);
275 }
276 
277 static const struct drm_plane_helper_funcs hdlcd_plane_helper_funcs = {
278 	.atomic_check = hdlcd_plane_atomic_check,
279 	.atomic_update = hdlcd_plane_atomic_update,
280 };
281 
282 static const struct drm_plane_funcs hdlcd_plane_funcs = {
283 	.update_plane		= drm_atomic_helper_update_plane,
284 	.disable_plane		= drm_atomic_helper_disable_plane,
285 	.destroy		= drm_plane_cleanup,
286 	.reset			= drm_atomic_helper_plane_reset,
287 	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
288 	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
289 };
290 
291 static struct drm_plane *hdlcd_plane_init(struct drm_device *drm)
292 {
293 	struct hdlcd_drm_private *hdlcd = drm->dev_private;
294 	struct drm_plane *plane = NULL;
295 	u32 formats[ARRAY_SIZE(supported_formats)], i;
296 	int ret;
297 
298 	plane = devm_kzalloc(drm->dev, sizeof(*plane), GFP_KERNEL);
299 	if (!plane)
300 		return ERR_PTR(-ENOMEM);
301 
302 	for (i = 0; i < ARRAY_SIZE(supported_formats); i++)
303 		formats[i] = supported_formats[i].fourcc;
304 
305 	ret = drm_universal_plane_init(drm, plane, 0xff, &hdlcd_plane_funcs,
306 				       formats, ARRAY_SIZE(formats),
307 				       NULL,
308 				       DRM_PLANE_TYPE_PRIMARY, NULL);
309 	if (ret)
310 		return ERR_PTR(ret);
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 		return ret;
332 
333 	drm_crtc_helper_add(&hdlcd->crtc, &hdlcd_crtc_helper_funcs);
334 	return 0;
335 }
336