1 // SPDX-License-Identifier: GPL-2.0+
2 // Copyright 2018 IBM Corporation
3 
4 #include <linux/clk.h>
5 #include <linux/reset.h>
6 #include <linux/regmap.h>
7 
8 #include <drm/drm_device.h>
9 #include <drm/drm_fb_dma_helper.h>
10 #include <drm/drm_fourcc.h>
11 #include <drm/drm_framebuffer.h>
12 #include <drm/drm_gem_atomic_helper.h>
13 #include <drm/drm_gem_dma_helper.h>
14 #include <drm/drm_panel.h>
15 #include <drm/drm_simple_kms_helper.h>
16 #include <drm/drm_vblank.h>
17 
18 #include "aspeed_gfx.h"
19 
20 static struct aspeed_gfx *
21 drm_pipe_to_aspeed_gfx(struct drm_simple_display_pipe *pipe)
22 {
23 	return container_of(pipe, struct aspeed_gfx, pipe);
24 }
25 
26 static int aspeed_gfx_set_pixel_fmt(struct aspeed_gfx *priv, u32 *bpp)
27 {
28 	struct drm_crtc *crtc = &priv->pipe.crtc;
29 	struct drm_device *drm = crtc->dev;
30 	const u32 format = crtc->primary->state->fb->format->format;
31 	u32 ctrl1;
32 
33 	ctrl1 = readl(priv->base + CRT_CTRL1);
34 	ctrl1 &= ~CRT_CTRL_COLOR_MASK;
35 
36 	switch (format) {
37 	case DRM_FORMAT_RGB565:
38 		dev_dbg(drm->dev, "Setting up RGB565 mode\n");
39 		ctrl1 |= CRT_CTRL_COLOR_RGB565;
40 		*bpp = 16;
41 		break;
42 	case DRM_FORMAT_XRGB8888:
43 		dev_dbg(drm->dev, "Setting up XRGB8888 mode\n");
44 		ctrl1 |= CRT_CTRL_COLOR_XRGB8888;
45 		*bpp = 32;
46 		break;
47 	default:
48 		dev_err(drm->dev, "Unhandled pixel format %08x\n", format);
49 		return -EINVAL;
50 	}
51 
52 	writel(ctrl1, priv->base + CRT_CTRL1);
53 
54 	return 0;
55 }
56 
57 static void aspeed_gfx_enable_controller(struct aspeed_gfx *priv)
58 {
59 	u32 ctrl1 = readl(priv->base + CRT_CTRL1);
60 	u32 ctrl2 = readl(priv->base + CRT_CTRL2);
61 
62 	/* Set DAC source for display output to Graphics CRT (GFX) */
63 	regmap_update_bits(priv->scu, priv->dac_reg, BIT(16), BIT(16));
64 
65 	writel(ctrl1 | CRT_CTRL_EN, priv->base + CRT_CTRL1);
66 	writel(ctrl2 | CRT_CTRL_DAC_EN, priv->base + CRT_CTRL2);
67 }
68 
69 static void aspeed_gfx_disable_controller(struct aspeed_gfx *priv)
70 {
71 	u32 ctrl1 = readl(priv->base + CRT_CTRL1);
72 	u32 ctrl2 = readl(priv->base + CRT_CTRL2);
73 
74 	writel(ctrl1 & ~CRT_CTRL_EN, priv->base + CRT_CTRL1);
75 	writel(ctrl2 & ~CRT_CTRL_DAC_EN, priv->base + CRT_CTRL2);
76 
77 	regmap_update_bits(priv->scu, priv->dac_reg, BIT(16), 0);
78 }
79 
80 static void aspeed_gfx_crtc_mode_set_nofb(struct aspeed_gfx *priv)
81 {
82 	struct drm_display_mode *m = &priv->pipe.crtc.state->adjusted_mode;
83 	u32 ctrl1, d_offset, t_count, bpp;
84 	int err;
85 
86 	err = aspeed_gfx_set_pixel_fmt(priv, &bpp);
87 	if (err)
88 		return;
89 
90 #if 0
91 	/* TODO: we have only been able to test with the 40MHz USB clock. The
92 	 * clock is fixed, so we cannot adjust it here. */
93 	clk_set_rate(priv->pixel_clk, m->crtc_clock * 1000);
94 #endif
95 
96 	ctrl1 = readl(priv->base + CRT_CTRL1);
97 	ctrl1 &= ~(CRT_CTRL_INTERLACED |
98 			CRT_CTRL_HSYNC_NEGATIVE |
99 			CRT_CTRL_VSYNC_NEGATIVE);
100 
101 	if (m->flags & DRM_MODE_FLAG_INTERLACE)
102 		ctrl1 |= CRT_CTRL_INTERLACED;
103 
104 	if (!(m->flags & DRM_MODE_FLAG_PHSYNC))
105 		ctrl1 |= CRT_CTRL_HSYNC_NEGATIVE;
106 
107 	if (!(m->flags & DRM_MODE_FLAG_PVSYNC))
108 		ctrl1 |= CRT_CTRL_VSYNC_NEGATIVE;
109 
110 	writel(ctrl1, priv->base + CRT_CTRL1);
111 
112 	/* Horizontal timing */
113 	writel(CRT_H_TOTAL(m->htotal - 1) | CRT_H_DE(m->hdisplay - 1),
114 			priv->base + CRT_HORIZ0);
115 	writel(CRT_H_RS_START(m->hsync_start - 1) | CRT_H_RS_END(m->hsync_end),
116 			priv->base + CRT_HORIZ1);
117 
118 
119 	/* Vertical timing */
120 	writel(CRT_V_TOTAL(m->vtotal - 1) | CRT_V_DE(m->vdisplay - 1),
121 			priv->base + CRT_VERT0);
122 	writel(CRT_V_RS_START(m->vsync_start) | CRT_V_RS_END(m->vsync_end),
123 			priv->base + CRT_VERT1);
124 
125 	/*
126 	 * Display Offset: address difference between consecutive scan lines
127 	 * Terminal Count: memory size of one scan line
128 	 */
129 	d_offset = m->hdisplay * bpp / 8;
130 	t_count = DIV_ROUND_UP(m->hdisplay * bpp, priv->scan_line_max);
131 
132 	writel(CRT_DISP_OFFSET(d_offset) | CRT_TERM_COUNT(t_count),
133 			priv->base + CRT_OFFSET);
134 
135 	/*
136 	 * Threshold: FIFO thresholds of refill and stop (16 byte chunks
137 	 * per line, rounded up)
138 	 */
139 	writel(priv->throd_val, priv->base + CRT_THROD);
140 }
141 
142 static void aspeed_gfx_pipe_enable(struct drm_simple_display_pipe *pipe,
143 			      struct drm_crtc_state *crtc_state,
144 			      struct drm_plane_state *plane_state)
145 {
146 	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
147 	struct drm_crtc *crtc = &pipe->crtc;
148 
149 	aspeed_gfx_crtc_mode_set_nofb(priv);
150 	aspeed_gfx_enable_controller(priv);
151 	drm_crtc_vblank_on(crtc);
152 }
153 
154 static void aspeed_gfx_pipe_disable(struct drm_simple_display_pipe *pipe)
155 {
156 	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
157 	struct drm_crtc *crtc = &pipe->crtc;
158 
159 	drm_crtc_vblank_off(crtc);
160 	aspeed_gfx_disable_controller(priv);
161 }
162 
163 static void aspeed_gfx_pipe_update(struct drm_simple_display_pipe *pipe,
164 				   struct drm_plane_state *plane_state)
165 {
166 	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
167 	struct drm_crtc *crtc = &pipe->crtc;
168 	struct drm_framebuffer *fb = pipe->plane.state->fb;
169 	struct drm_pending_vblank_event *event;
170 	struct drm_gem_dma_object *gem;
171 
172 	spin_lock_irq(&crtc->dev->event_lock);
173 	event = crtc->state->event;
174 	if (event) {
175 		crtc->state->event = NULL;
176 
177 		if (drm_crtc_vblank_get(crtc) == 0)
178 			drm_crtc_arm_vblank_event(crtc, event);
179 		else
180 			drm_crtc_send_vblank_event(crtc, event);
181 	}
182 	spin_unlock_irq(&crtc->dev->event_lock);
183 
184 	if (!fb)
185 		return;
186 
187 	gem = drm_fb_dma_get_gem_obj(fb, 0);
188 	if (!gem)
189 		return;
190 	writel(gem->dma_addr, priv->base + CRT_ADDR);
191 }
192 
193 static int aspeed_gfx_enable_vblank(struct drm_simple_display_pipe *pipe)
194 {
195 	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
196 	u32 reg = readl(priv->base + CRT_CTRL1);
197 
198 	/* Clear pending VBLANK IRQ */
199 	writel(reg | CRT_CTRL_VERTICAL_INTR_STS, priv->base + CRT_CTRL1);
200 
201 	reg |= CRT_CTRL_VERTICAL_INTR_EN;
202 	writel(reg, priv->base + CRT_CTRL1);
203 
204 	return 0;
205 }
206 
207 static void aspeed_gfx_disable_vblank(struct drm_simple_display_pipe *pipe)
208 {
209 	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
210 	u32 reg = readl(priv->base + CRT_CTRL1);
211 
212 	reg &= ~CRT_CTRL_VERTICAL_INTR_EN;
213 	writel(reg, priv->base + CRT_CTRL1);
214 
215 	/* Clear pending VBLANK IRQ */
216 	writel(reg | CRT_CTRL_VERTICAL_INTR_STS, priv->base + CRT_CTRL1);
217 }
218 
219 static const struct drm_simple_display_pipe_funcs aspeed_gfx_funcs = {
220 	.enable		= aspeed_gfx_pipe_enable,
221 	.disable	= aspeed_gfx_pipe_disable,
222 	.update		= aspeed_gfx_pipe_update,
223 	.enable_vblank	= aspeed_gfx_enable_vblank,
224 	.disable_vblank	= aspeed_gfx_disable_vblank,
225 };
226 
227 static const uint32_t aspeed_gfx_formats[] = {
228 	DRM_FORMAT_XRGB8888,
229 	DRM_FORMAT_RGB565,
230 };
231 
232 int aspeed_gfx_create_pipe(struct drm_device *drm)
233 {
234 	struct aspeed_gfx *priv = to_aspeed_gfx(drm);
235 
236 	return drm_simple_display_pipe_init(drm, &priv->pipe, &aspeed_gfx_funcs,
237 					    aspeed_gfx_formats,
238 					    ARRAY_SIZE(aspeed_gfx_formats),
239 					    NULL,
240 					    &priv->connector);
241 }
242