1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
4  * Parts of this file were based on sources as follows:
5  *
6  * Copyright (C) 2006-2008 Intel Corporation
7  * Copyright (C) 2007 Amos Lee <amos_lee@storlinksemi.com>
8  * Copyright (C) 2007 Dave Airlie <airlied@linux.ie>
9  * Copyright (C) 2011 Texas Instruments
10  * Copyright (C) 2017 Eric Anholt
11  */
12 
13 /**
14  * DOC: Faraday TV Encoder TVE200 DRM Driver
15  *
16  * The Faraday TV Encoder TVE200 is also known as the Gemini TV Interface
17  * Controller (TVC) and is found in the Gemini Chipset from Storlink
18  * Semiconductor (later Storm Semiconductor, later Cortina Systems)
19  * but also in the Grain Media GM8180 chipset. On the Gemini the module
20  * is connected to 8 data lines and a single clock line, comprising an
21  * 8-bit BT.656 interface.
22  *
23  * This is a very basic YUV display driver. The datasheet specifies that
24  * it supports the ITU BT.656 standard. It requires a 27 MHz clock which is
25  * the hallmark of any TV encoder supporting both PAL and NTSC.
26  *
27  * This driver exposes a standard KMS interface for this TV encoder.
28  */
29 
30 #include <linux/clk.h>
31 #include <linux/dma-buf.h>
32 #include <linux/irq.h>
33 #include <linux/io.h>
34 #include <linux/module.h>
35 #include <linux/of.h>
36 #include <linux/platform_device.h>
37 #include <linux/shmem_fs.h>
38 #include <linux/slab.h>
39 
40 #include <drm/drm_atomic_helper.h>
41 #include <drm/drm_bridge.h>
42 #include <drm/drm_drv.h>
43 #include <drm/drm_fbdev_dma.h>
44 #include <drm/drm_gem_dma_helper.h>
45 #include <drm/drm_gem_framebuffer_helper.h>
46 #include <drm/drm_module.h>
47 #include <drm/drm_of.h>
48 #include <drm/drm_panel.h>
49 #include <drm/drm_probe_helper.h>
50 #include <drm/drm_vblank.h>
51 
52 #include "tve200_drm.h"
53 
54 #define DRIVER_DESC      "DRM module for Faraday TVE200"
55 
56 static const struct drm_mode_config_funcs mode_config_funcs = {
57 	.fb_create = drm_gem_fb_create,
58 	.atomic_check = drm_atomic_helper_check,
59 	.atomic_commit = drm_atomic_helper_commit,
60 };
61 
62 static int tve200_modeset_init(struct drm_device *dev)
63 {
64 	struct drm_mode_config *mode_config;
65 	struct tve200_drm_dev_private *priv = dev->dev_private;
66 	struct drm_panel *panel;
67 	struct drm_bridge *bridge;
68 	int ret;
69 
70 	drm_mode_config_init(dev);
71 	mode_config = &dev->mode_config;
72 	mode_config->funcs = &mode_config_funcs;
73 	mode_config->min_width = 352;
74 	mode_config->max_width = 720;
75 	mode_config->min_height = 240;
76 	mode_config->max_height = 576;
77 
78 	ret = drm_of_find_panel_or_bridge(dev->dev->of_node,
79 					  0, 0, &panel, &bridge);
80 	if (ret && ret != -ENODEV)
81 		return ret;
82 	if (panel) {
83 		bridge = drm_panel_bridge_add_typed(panel,
84 						    DRM_MODE_CONNECTOR_Unknown);
85 		if (IS_ERR(bridge)) {
86 			ret = PTR_ERR(bridge);
87 			goto out_bridge;
88 		}
89 	} else {
90 		/*
91 		 * TODO: when we are using a different bridge than a panel
92 		 * (such as a dumb VGA connector) we need to devise a different
93 		 * method to get the connector out of the bridge.
94 		 */
95 		dev_err(dev->dev, "the bridge is not a panel\n");
96 		ret = -EINVAL;
97 		goto out_bridge;
98 	}
99 
100 	ret = tve200_display_init(dev);
101 	if (ret) {
102 		dev_err(dev->dev, "failed to init display\n");
103 		goto out_bridge;
104 	}
105 
106 	ret = drm_simple_display_pipe_attach_bridge(&priv->pipe,
107 						    bridge);
108 	if (ret) {
109 		dev_err(dev->dev, "failed to attach bridge\n");
110 		goto out_bridge;
111 	}
112 
113 	priv->panel = panel;
114 	priv->connector = drm_panel_bridge_connector(bridge);
115 	priv->bridge = bridge;
116 
117 	dev_info(dev->dev, "attached to panel %s\n",
118 		 dev_name(panel->dev));
119 
120 	ret = drm_vblank_init(dev, 1);
121 	if (ret) {
122 		dev_err(dev->dev, "failed to init vblank\n");
123 		goto out_bridge;
124 	}
125 
126 	drm_mode_config_reset(dev);
127 	drm_kms_helper_poll_init(dev);
128 
129 	goto finish;
130 
131 out_bridge:
132 	if (panel)
133 		drm_panel_bridge_remove(bridge);
134 	drm_mode_config_cleanup(dev);
135 finish:
136 	return ret;
137 }
138 
139 DEFINE_DRM_GEM_DMA_FOPS(drm_fops);
140 
141 static const struct drm_driver tve200_drm_driver = {
142 	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
143 	.ioctls = NULL,
144 	.fops = &drm_fops,
145 	.name = "tve200",
146 	.desc = DRIVER_DESC,
147 	.date = "20170703",
148 	.major = 1,
149 	.minor = 0,
150 	.patchlevel = 0,
151 	DRM_GEM_DMA_DRIVER_OPS,
152 };
153 
154 static int tve200_probe(struct platform_device *pdev)
155 {
156 	struct device *dev = &pdev->dev;
157 	struct tve200_drm_dev_private *priv;
158 	struct drm_device *drm;
159 	struct resource *res;
160 	int irq;
161 	int ret;
162 
163 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
164 	if (!priv)
165 		return -ENOMEM;
166 
167 	drm = drm_dev_alloc(&tve200_drm_driver, dev);
168 	if (IS_ERR(drm))
169 		return PTR_ERR(drm);
170 	platform_set_drvdata(pdev, drm);
171 	priv->drm = drm;
172 	drm->dev_private = priv;
173 
174 	/* Clock the silicon so we can access the registers */
175 	priv->pclk = devm_clk_get(dev, "PCLK");
176 	if (IS_ERR(priv->pclk)) {
177 		dev_err(dev, "unable to get PCLK\n");
178 		ret = PTR_ERR(priv->pclk);
179 		goto dev_unref;
180 	}
181 	ret = clk_prepare_enable(priv->pclk);
182 	if (ret) {
183 		dev_err(dev, "failed to enable PCLK\n");
184 		goto dev_unref;
185 	}
186 
187 	/* This clock is for the pixels (27MHz) */
188 	priv->clk = devm_clk_get(dev, "TVE");
189 	if (IS_ERR(priv->clk)) {
190 		dev_err(dev, "unable to get TVE clock\n");
191 		ret = PTR_ERR(priv->clk);
192 		goto clk_disable;
193 	}
194 
195 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
196 	priv->regs = devm_ioremap_resource(dev, res);
197 	if (IS_ERR(priv->regs)) {
198 		dev_err(dev, "%s failed mmio\n", __func__);
199 		ret = -EINVAL;
200 		goto clk_disable;
201 	}
202 
203 	irq = platform_get_irq(pdev, 0);
204 	if (irq < 0) {
205 		ret = irq;
206 		goto clk_disable;
207 	}
208 
209 	/* turn off interrupts before requesting the irq */
210 	writel(0, priv->regs + TVE200_INT_EN);
211 
212 	ret = devm_request_irq(dev, irq, tve200_irq, 0, "tve200", priv);
213 	if (ret) {
214 		dev_err(dev, "failed to request irq %d\n", ret);
215 		goto clk_disable;
216 	}
217 
218 	ret = tve200_modeset_init(drm);
219 	if (ret)
220 		goto clk_disable;
221 
222 	ret = drm_dev_register(drm, 0);
223 	if (ret < 0)
224 		goto clk_disable;
225 
226 	/*
227 	 * Passing in 16 here will make the RGB565 mode the default
228 	 * Passing in 32 will use XRGB8888 mode
229 	 */
230 	drm_fbdev_dma_setup(drm, 16);
231 
232 	return 0;
233 
234 clk_disable:
235 	clk_disable_unprepare(priv->pclk);
236 dev_unref:
237 	drm_dev_put(drm);
238 	return ret;
239 }
240 
241 static int tve200_remove(struct platform_device *pdev)
242 {
243 	struct drm_device *drm = platform_get_drvdata(pdev);
244 	struct tve200_drm_dev_private *priv = drm->dev_private;
245 
246 	drm_dev_unregister(drm);
247 	if (priv->panel)
248 		drm_panel_bridge_remove(priv->bridge);
249 	drm_mode_config_cleanup(drm);
250 	clk_disable_unprepare(priv->pclk);
251 	drm_dev_put(drm);
252 
253 	return 0;
254 }
255 
256 static const struct of_device_id tve200_of_match[] = {
257 	{
258 		.compatible = "faraday,tve200",
259 	},
260 	{},
261 };
262 
263 static struct platform_driver tve200_driver = {
264 	.driver = {
265 		.name           = "tve200",
266 		.of_match_table = of_match_ptr(tve200_of_match),
267 	},
268 	.probe = tve200_probe,
269 	.remove = tve200_remove,
270 };
271 drm_module_platform_driver(tve200_driver);
272 
273 MODULE_DESCRIPTION(DRIVER_DESC);
274 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
275 MODULE_LICENSE("GPL");
276