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_crtc_helper.h>
9 #include <drm/drm_device.h>
10 #include <drm/drm_fb_dma_helper.h>
11 #include <drm/drm_fourcc.h>
12 #include <drm/drm_framebuffer.h>
13 #include <drm/drm_gem_atomic_helper.h>
14 #include <drm/drm_gem_dma_helper.h>
15 #include <drm/drm_panel.h>
16 #include <drm/drm_simple_kms_helper.h>
17 #include <drm/drm_vblank.h>
18 
19 #include "aspeed_gfx.h"
20 
21 static struct aspeed_gfx *
22 drm_pipe_to_aspeed_gfx(struct drm_simple_display_pipe *pipe)
23 {
24 	return container_of(pipe, struct aspeed_gfx, pipe);
25 }
26 
27 static int aspeed_gfx_set_pixel_fmt(struct aspeed_gfx *priv, u32 *bpp)
28 {
29 	struct drm_crtc *crtc = &priv->pipe.crtc;
30 	struct drm_device *drm = crtc->dev;
31 	const u32 format = crtc->primary->state->fb->format->format;
32 	u32 ctrl1;
33 
34 	ctrl1 = readl(priv->base + CRT_CTRL1);
35 	ctrl1 &= ~CRT_CTRL_COLOR_MASK;
36 
37 	switch (format) {
38 	case DRM_FORMAT_RGB565:
39 		dev_dbg(drm->dev, "Setting up RGB565 mode\n");
40 		ctrl1 |= CRT_CTRL_COLOR_RGB565;
41 		*bpp = 16;
42 		break;
43 	case DRM_FORMAT_XRGB8888:
44 		dev_dbg(drm->dev, "Setting up XRGB8888 mode\n");
45 		ctrl1 |= CRT_CTRL_COLOR_XRGB8888;
46 		*bpp = 32;
47 		break;
48 	default:
49 		dev_err(drm->dev, "Unhandled pixel format %08x\n", format);
50 		return -EINVAL;
51 	}
52 
53 	writel(ctrl1, priv->base + CRT_CTRL1);
54 
55 	return 0;
56 }
57 
58 static void aspeed_gfx_enable_controller(struct aspeed_gfx *priv)
59 {
60 	u32 ctrl1 = readl(priv->base + CRT_CTRL1);
61 	u32 ctrl2 = readl(priv->base + CRT_CTRL2);
62 
63 	/* Set DAC source for display output to Graphics CRT (GFX) */
64 	regmap_update_bits(priv->scu, priv->dac_reg, BIT(16), BIT(16));
65 
66 	writel(ctrl1 | CRT_CTRL_EN, priv->base + CRT_CTRL1);
67 	writel(ctrl2 | CRT_CTRL_DAC_EN, priv->base + CRT_CTRL2);
68 }
69 
70 static void aspeed_gfx_disable_controller(struct aspeed_gfx *priv)
71 {
72 	u32 ctrl1 = readl(priv->base + CRT_CTRL1);
73 	u32 ctrl2 = readl(priv->base + CRT_CTRL2);
74 
75 	writel(ctrl1 & ~CRT_CTRL_EN, priv->base + CRT_CTRL1);
76 	writel(ctrl2 & ~CRT_CTRL_DAC_EN, priv->base + CRT_CTRL2);
77 
78 	regmap_update_bits(priv->scu, priv->dac_reg, BIT(16), 0);
79 }
80 
81 static void aspeed_gfx_crtc_mode_set_nofb(struct aspeed_gfx *priv)
82 {
83 	struct drm_display_mode *m = &priv->pipe.crtc.state->adjusted_mode;
84 	u32 ctrl1, d_offset, t_count, bpp;
85 	int err;
86 
87 	err = aspeed_gfx_set_pixel_fmt(priv, &bpp);
88 	if (err)
89 		return;
90 
91 #if 0
92 	/* TODO: we have only been able to test with the 40MHz USB clock. The
93 	 * clock is fixed, so we cannot adjust it here. */
94 	clk_set_rate(priv->pixel_clk, m->crtc_clock * 1000);
95 #endif
96 
97 	ctrl1 = readl(priv->base + CRT_CTRL1);
98 	ctrl1 &= ~(CRT_CTRL_INTERLACED |
99 			CRT_CTRL_HSYNC_NEGATIVE |
100 			CRT_CTRL_VSYNC_NEGATIVE);
101 
102 	if (m->flags & DRM_MODE_FLAG_INTERLACE)
103 		ctrl1 |= CRT_CTRL_INTERLACED;
104 
105 	if (!(m->flags & DRM_MODE_FLAG_PHSYNC))
106 		ctrl1 |= CRT_CTRL_HSYNC_NEGATIVE;
107 
108 	if (!(m->flags & DRM_MODE_FLAG_PVSYNC))
109 		ctrl1 |= CRT_CTRL_VSYNC_NEGATIVE;
110 
111 	writel(ctrl1, priv->base + CRT_CTRL1);
112 
113 	/* Horizontal timing */
114 	writel(CRT_H_TOTAL(m->htotal - 1) | CRT_H_DE(m->hdisplay - 1),
115 			priv->base + CRT_HORIZ0);
116 	writel(CRT_H_RS_START(m->hsync_start - 1) | CRT_H_RS_END(m->hsync_end),
117 			priv->base + CRT_HORIZ1);
118 
119 
120 	/* Vertical timing */
121 	writel(CRT_V_TOTAL(m->vtotal - 1) | CRT_V_DE(m->vdisplay - 1),
122 			priv->base + CRT_VERT0);
123 	writel(CRT_V_RS_START(m->vsync_start) | CRT_V_RS_END(m->vsync_end),
124 			priv->base + CRT_VERT1);
125 
126 	/*
127 	 * Display Offset: address difference between consecutive scan lines
128 	 * Terminal Count: memory size of one scan line
129 	 */
130 	d_offset = m->hdisplay * bpp / 8;
131 	t_count = DIV_ROUND_UP(m->hdisplay * bpp, priv->scan_line_max);
132 
133 	writel(CRT_DISP_OFFSET(d_offset) | CRT_TERM_COUNT(t_count),
134 			priv->base + CRT_OFFSET);
135 
136 	/*
137 	 * Threshold: FIFO thresholds of refill and stop (16 byte chunks
138 	 * per line, rounded up)
139 	 */
140 	writel(priv->throd_val, priv->base + CRT_THROD);
141 }
142 
143 static void aspeed_gfx_pipe_enable(struct drm_simple_display_pipe *pipe,
144 			      struct drm_crtc_state *crtc_state,
145 			      struct drm_plane_state *plane_state)
146 {
147 	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
148 	struct drm_crtc *crtc = &pipe->crtc;
149 
150 	aspeed_gfx_crtc_mode_set_nofb(priv);
151 	aspeed_gfx_enable_controller(priv);
152 	drm_crtc_vblank_on(crtc);
153 }
154 
155 static void aspeed_gfx_pipe_disable(struct drm_simple_display_pipe *pipe)
156 {
157 	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
158 	struct drm_crtc *crtc = &pipe->crtc;
159 
160 	drm_crtc_vblank_off(crtc);
161 	aspeed_gfx_disable_controller(priv);
162 }
163 
164 static void aspeed_gfx_pipe_update(struct drm_simple_display_pipe *pipe,
165 				   struct drm_plane_state *plane_state)
166 {
167 	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
168 	struct drm_crtc *crtc = &pipe->crtc;
169 	struct drm_framebuffer *fb = pipe->plane.state->fb;
170 	struct drm_pending_vblank_event *event;
171 	struct drm_gem_dma_object *gem;
172 
173 	spin_lock_irq(&crtc->dev->event_lock);
174 	event = crtc->state->event;
175 	if (event) {
176 		crtc->state->event = NULL;
177 
178 		if (drm_crtc_vblank_get(crtc) == 0)
179 			drm_crtc_arm_vblank_event(crtc, event);
180 		else
181 			drm_crtc_send_vblank_event(crtc, event);
182 	}
183 	spin_unlock_irq(&crtc->dev->event_lock);
184 
185 	if (!fb)
186 		return;
187 
188 	gem = drm_fb_dma_get_gem_obj(fb, 0);
189 	if (!gem)
190 		return;
191 	writel(gem->dma_addr, priv->base + CRT_ADDR);
192 }
193 
194 static int aspeed_gfx_enable_vblank(struct drm_simple_display_pipe *pipe)
195 {
196 	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
197 	u32 reg = readl(priv->base + CRT_CTRL1);
198 
199 	/* Clear pending VBLANK IRQ */
200 	writel(reg | CRT_CTRL_VERTICAL_INTR_STS, priv->base + CRT_CTRL1);
201 
202 	reg |= CRT_CTRL_VERTICAL_INTR_EN;
203 	writel(reg, priv->base + CRT_CTRL1);
204 
205 	return 0;
206 }
207 
208 static void aspeed_gfx_disable_vblank(struct drm_simple_display_pipe *pipe)
209 {
210 	struct aspeed_gfx *priv = drm_pipe_to_aspeed_gfx(pipe);
211 	u32 reg = readl(priv->base + CRT_CTRL1);
212 
213 	reg &= ~CRT_CTRL_VERTICAL_INTR_EN;
214 	writel(reg, priv->base + CRT_CTRL1);
215 
216 	/* Clear pending VBLANK IRQ */
217 	writel(reg | CRT_CTRL_VERTICAL_INTR_STS, priv->base + CRT_CTRL1);
218 }
219 
220 static const struct drm_simple_display_pipe_funcs aspeed_gfx_funcs = {
221 	.enable		= aspeed_gfx_pipe_enable,
222 	.disable	= aspeed_gfx_pipe_disable,
223 	.update		= aspeed_gfx_pipe_update,
224 	.enable_vblank	= aspeed_gfx_enable_vblank,
225 	.disable_vblank	= aspeed_gfx_disable_vblank,
226 };
227 
228 static const uint32_t aspeed_gfx_formats[] = {
229 	DRM_FORMAT_XRGB8888,
230 	DRM_FORMAT_RGB565,
231 };
232 
233 int aspeed_gfx_create_pipe(struct drm_device *drm)
234 {
235 	struct aspeed_gfx *priv = to_aspeed_gfx(drm);
236 
237 	return drm_simple_display_pipe_init(drm, &priv->pipe, &aspeed_gfx_funcs,
238 					    aspeed_gfx_formats,
239 					    ARRAY_SIZE(aspeed_gfx_formats),
240 					    NULL,
241 					    &priv->connector);
242 }
243