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
 36static const struct drm_crtc_funcs hdlcd_crtc_funcs = {
 37	.destroy = drm_crtc_cleanup,
 38	.set_config = drm_atomic_helper_set_config,
 39	.page_flip = drm_atomic_helper_page_flip,
 40	.reset = drm_atomic_helper_crtc_reset,
 41	.atomic_duplicate_state = drm_atomic_helper_crtc_duplicate_state,
 42	.atomic_destroy_state = drm_atomic_helper_crtc_destroy_state,
 43};
 44
 45static struct simplefb_format supported_formats[] = SIMPLEFB_FORMATS;
 46
 47/*
 48 * Setup the HDLCD registers for decoding the pixels out of the framebuffer
 49 */
 50static int hdlcd_set_pxl_fmt(struct drm_crtc *crtc)
 51{
 52	unsigned int btpp;
 53	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
 54	uint32_t pixel_format;
 55	struct simplefb_format *format = NULL;
 56	int i;
 57
 58	pixel_format = crtc->primary->state->fb->pixel_format;
 59
 60	for (i = 0; i < ARRAY_SIZE(supported_formats); i++) {
 61		if (supported_formats[i].fourcc == pixel_format)
 62			format = &supported_formats[i];
 63	}
 64
 65	if (WARN_ON(!format))
 66		return 0;
 67
 68	/* HDLCD uses 'bytes per pixel', zero means 1 byte */
 69	btpp = (format->bits_per_pixel + 7) / 8;
 70	hdlcd_write(hdlcd, HDLCD_REG_PIXEL_FORMAT, (btpp - 1) << 3);
 71
 72	/*
 73	 * The format of the HDLCD_REG_<color>_SELECT register is:
 74	 *   - bits[23:16] - default value for that color component
 75	 *   - bits[11:8]  - number of bits to extract for each color component
 76	 *   - bits[4:0]   - index of the lowest bit to extract
 77	 *
 78	 * The default color value is used when bits[11:8] are zero, when the
 79	 * pixel is outside the visible frame area or when there is a
 80	 * buffer underrun.
 81	 */
 82	hdlcd_write(hdlcd, HDLCD_REG_RED_SELECT, format->red.offset |
 83#ifdef CONFIG_DRM_HDLCD_SHOW_UNDERRUN
 84		    0x00ff0000 |	/* show underruns in red */
 85#endif
 86		    ((format->red.length & 0xf) << 8));
 87	hdlcd_write(hdlcd, HDLCD_REG_GREEN_SELECT, format->green.offset |
 88		    ((format->green.length & 0xf) << 8));
 89	hdlcd_write(hdlcd, HDLCD_REG_BLUE_SELECT, format->blue.offset |
 90		    ((format->blue.length & 0xf) << 8));
 91
 92	return 0;
 93}
 94
 95static void hdlcd_crtc_mode_set_nofb(struct drm_crtc *crtc)
 96{
 97	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
 98	struct drm_display_mode *m = &crtc->state->adjusted_mode;
 99	struct videomode vm;
100	unsigned int polarities, line_length, err;
101
102	vm.vfront_porch = m->crtc_vsync_start - m->crtc_vdisplay;
103	vm.vback_porch = m->crtc_vtotal - m->crtc_vsync_end;
104	vm.vsync_len = m->crtc_vsync_end - m->crtc_vsync_start;
105	vm.hfront_porch = m->crtc_hsync_start - m->crtc_hdisplay;
106	vm.hback_porch = m->crtc_htotal - m->crtc_hsync_end;
107	vm.hsync_len = m->crtc_hsync_end - m->crtc_hsync_start;
108
109	polarities = HDLCD_POLARITY_DATAEN | HDLCD_POLARITY_DATA;
110
111	if (m->flags & DRM_MODE_FLAG_PHSYNC)
112		polarities |= HDLCD_POLARITY_HSYNC;
113	if (m->flags & DRM_MODE_FLAG_PVSYNC)
114		polarities |= HDLCD_POLARITY_VSYNC;
115
116	line_length = crtc->primary->state->fb->pitches[0];
117
118	/* Allow max number of outstanding requests and largest burst size */
119	hdlcd_write(hdlcd, HDLCD_REG_BUS_OPTIONS,
120		    HDLCD_BUS_MAX_OUTSTAND | HDLCD_BUS_BURST_16);
121
122	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_LENGTH, line_length);
123	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_PITCH, line_length);
124	hdlcd_write(hdlcd, HDLCD_REG_FB_LINE_COUNT, m->crtc_vdisplay - 1);
125	hdlcd_write(hdlcd, HDLCD_REG_V_DATA, m->crtc_vdisplay - 1);
126	hdlcd_write(hdlcd, HDLCD_REG_V_BACK_PORCH, vm.vback_porch - 1);
127	hdlcd_write(hdlcd, HDLCD_REG_V_FRONT_PORCH, vm.vfront_porch - 1);
128	hdlcd_write(hdlcd, HDLCD_REG_V_SYNC, vm.vsync_len - 1);
129	hdlcd_write(hdlcd, HDLCD_REG_H_BACK_PORCH, vm.hback_porch - 1);
130	hdlcd_write(hdlcd, HDLCD_REG_H_FRONT_PORCH, vm.hfront_porch - 1);
131	hdlcd_write(hdlcd, HDLCD_REG_H_SYNC, vm.hsync_len - 1);
132	hdlcd_write(hdlcd, HDLCD_REG_H_DATA, m->crtc_hdisplay - 1);
133	hdlcd_write(hdlcd, HDLCD_REG_POLARITIES, polarities);
134
135	err = hdlcd_set_pxl_fmt(crtc);
136	if (err)
137		return;
138
139	clk_set_rate(hdlcd->clk, m->crtc_clock * 1000);
140}
141
142static void hdlcd_crtc_enable(struct drm_crtc *crtc)
143{
144	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
145
146	clk_prepare_enable(hdlcd->clk);
147	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 1);
148	drm_crtc_vblank_on(crtc);
149}
150
151static void hdlcd_crtc_disable(struct drm_crtc *crtc)
152{
153	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
154
155	if (!crtc->primary->fb)
156		return;
157
158	clk_disable_unprepare(hdlcd->clk);
159	hdlcd_write(hdlcd, HDLCD_REG_COMMAND, 0);
160	drm_crtc_vblank_off(crtc);
161}
162
163static int hdlcd_crtc_atomic_check(struct drm_crtc *crtc,
164				   struct drm_crtc_state *state)
165{
166	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
167	struct drm_display_mode *mode = &state->adjusted_mode;
168	long rate, clk_rate = mode->clock * 1000;
169
170	rate = clk_round_rate(hdlcd->clk, clk_rate);
171	if (rate != clk_rate) {
172		/* clock required by mode not supported by hardware */
173		return -EINVAL;
174	}
175
176	return 0;
177}
178
179static void hdlcd_crtc_atomic_begin(struct drm_crtc *crtc,
180				    struct drm_crtc_state *state)
181{
182	struct hdlcd_drm_private *hdlcd = crtc_to_hdlcd_priv(crtc);
183	unsigned long flags;
184
185	if (crtc->state->event) {
186		struct drm_pending_vblank_event *event = crtc->state->event;
187
188		crtc->state->event = NULL;
189		event->pipe = drm_crtc_index(crtc);
190
191		WARN_ON(drm_crtc_vblank_get(crtc) != 0);
192
193		spin_lock_irqsave(&crtc->dev->event_lock, flags);
194		list_add_tail(&event->base.link, &hdlcd->event_list);
195		spin_unlock_irqrestore(&crtc->dev->event_lock, flags);
196	}
197}
198
199static void hdlcd_crtc_atomic_flush(struct drm_crtc *crtc,
200				    struct drm_crtc_state *state)
201{
202}
203
204static bool hdlcd_crtc_mode_fixup(struct drm_crtc *crtc,
205			const struct drm_display_mode *mode,
206			struct drm_display_mode *adjusted_mode)
207{
208	return true;
209}
210
211static const struct drm_crtc_helper_funcs hdlcd_crtc_helper_funcs = {
212	.mode_fixup	= hdlcd_crtc_mode_fixup,
213	.mode_set	= drm_helper_crtc_mode_set,
214	.mode_set_base	= drm_helper_crtc_mode_set_base,
215	.mode_set_nofb	= hdlcd_crtc_mode_set_nofb,
216	.enable		= hdlcd_crtc_enable,
217	.disable	= hdlcd_crtc_disable,
218	.prepare	= hdlcd_crtc_disable,
219	.commit		= hdlcd_crtc_enable,
220	.atomic_check	= hdlcd_crtc_atomic_check,
221	.atomic_begin	= hdlcd_crtc_atomic_begin,
222	.atomic_flush	= hdlcd_crtc_atomic_flush,
223};
224
225static int hdlcd_plane_atomic_check(struct drm_plane *plane,
226				    struct drm_plane_state *state)
227{
228	return 0;
229}
230
231static void hdlcd_plane_atomic_update(struct drm_plane *plane,
232				      struct drm_plane_state *state)
233{
234	struct hdlcd_drm_private *hdlcd;
235	struct drm_gem_cma_object *gem;
236	dma_addr_t scanout_start;
237
238	if (!plane->state->crtc || !plane->state->fb)
239		return;
240
241	hdlcd = crtc_to_hdlcd_priv(plane->state->crtc);
242	gem = drm_fb_cma_get_gem_obj(plane->state->fb, 0);
243	scanout_start = gem->paddr;
244	hdlcd_write(hdlcd, HDLCD_REG_FB_BASE, scanout_start);
245}
246
247static const struct drm_plane_helper_funcs hdlcd_plane_helper_funcs = {
248	.prepare_fb = NULL,
249	.cleanup_fb = NULL,
250	.atomic_check = hdlcd_plane_atomic_check,
251	.atomic_update = hdlcd_plane_atomic_update,
252};
253
254static void hdlcd_plane_destroy(struct drm_plane *plane)
255{
256	drm_plane_helper_disable(plane);
257	drm_plane_cleanup(plane);
258}
259
260static const struct drm_plane_funcs hdlcd_plane_funcs = {
261	.update_plane		= drm_atomic_helper_update_plane,
262	.disable_plane		= drm_atomic_helper_disable_plane,
263	.destroy		= hdlcd_plane_destroy,
264	.reset			= drm_atomic_helper_plane_reset,
265	.atomic_duplicate_state = drm_atomic_helper_plane_duplicate_state,
266	.atomic_destroy_state	= drm_atomic_helper_plane_destroy_state,
267};
268
269static struct drm_plane *hdlcd_plane_init(struct drm_device *drm)
270{
271	struct hdlcd_drm_private *hdlcd = drm->dev_private;
272	struct drm_plane *plane = NULL;
273	u32 formats[ARRAY_SIZE(supported_formats)], i;
274	int ret;
275
276	plane = devm_kzalloc(drm->dev, sizeof(*plane), GFP_KERNEL);
277	if (!plane)
278		return ERR_PTR(-ENOMEM);
279
280	for (i = 0; i < ARRAY_SIZE(supported_formats); i++)
281		formats[i] = supported_formats[i].fourcc;
282
283	ret = drm_universal_plane_init(drm, plane, 0xff, &hdlcd_plane_funcs,
284				       formats, ARRAY_SIZE(formats),
285				       DRM_PLANE_TYPE_PRIMARY, NULL);
286	if (ret) {
287		devm_kfree(drm->dev, plane);
288		return ERR_PTR(ret);
289	}
290
291	drm_plane_helper_add(plane, &hdlcd_plane_helper_funcs);
292	hdlcd->plane = plane;
293
294	return plane;
295}
296
297void hdlcd_crtc_suspend(struct drm_crtc *crtc)
298{
299	hdlcd_crtc_disable(crtc);
300}
301
302void hdlcd_crtc_resume(struct drm_crtc *crtc)
303{
304	hdlcd_crtc_enable(crtc);
305}
306
307int hdlcd_setup_crtc(struct drm_device *drm)
308{
309	struct hdlcd_drm_private *hdlcd = drm->dev_private;
310	struct drm_plane *primary;
311	int ret;
312
313	primary = hdlcd_plane_init(drm);
314	if (IS_ERR(primary))
315		return PTR_ERR(primary);
316
317	ret = drm_crtc_init_with_planes(drm, &hdlcd->crtc, primary, NULL,
318					&hdlcd_crtc_funcs, NULL);
319	if (ret) {
320		hdlcd_plane_destroy(primary);
321		devm_kfree(drm->dev, primary);
322		return ret;
323	}
324
325	drm_crtc_helper_add(&hdlcd->crtc, &hdlcd_crtc_helper_funcs);
326	return 0;
327}