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/platform_device.h>
36 #include <linux/shmem_fs.h>
37 #include <linux/slab.h>
38 
39 #include <drm/drm_atomic_helper.h>
40 #include <drm/drm_bridge.h>
41 #include <drm/drm_drv.h>
42 #include <drm/drm_fb_cma_helper.h>
43 #include <drm/drm_fb_helper.h>
44 #include <drm/drm_gem_cma_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 = 0;
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 		goto out_bridge;
97 	}
98 
99 	ret = tve200_display_init(dev);
100 	if (ret) {
101 		dev_err(dev->dev, "failed to init display\n");
102 		goto out_bridge;
103 	}
104 
105 	ret = drm_simple_display_pipe_attach_bridge(&priv->pipe,
106 						    bridge);
107 	if (ret) {
108 		dev_err(dev->dev, "failed to attach bridge\n");
109 		goto out_bridge;
110 	}
111 
112 	priv->panel = panel;
113 	priv->connector = drm_panel_bridge_connector(bridge);
114 	priv->bridge = bridge;
115 
116 	dev_info(dev->dev, "attached to panel %s\n",
117 		 dev_name(panel->dev));
118 
119 	ret = drm_vblank_init(dev, 1);
120 	if (ret) {
121 		dev_err(dev->dev, "failed to init vblank\n");
122 		goto out_bridge;
123 	}
124 
125 	drm_mode_config_reset(dev);
126 	drm_kms_helper_poll_init(dev);
127 
128 	goto finish;
129 
130 out_bridge:
131 	if (panel)
132 		drm_panel_bridge_remove(bridge);
133 	drm_mode_config_cleanup(dev);
134 finish:
135 	return ret;
136 }
137 
138 DEFINE_DRM_GEM_CMA_FOPS(drm_fops);
139 
140 static const struct drm_driver tve200_drm_driver = {
141 	.driver_features = DRIVER_MODESET | DRIVER_GEM | DRIVER_ATOMIC,
142 	.ioctls = NULL,
143 	.fops = &drm_fops,
144 	.name = "tve200",
145 	.desc = DRIVER_DESC,
146 	.date = "20170703",
147 	.major = 1,
148 	.minor = 0,
149 	.patchlevel = 0,
150 	DRM_GEM_CMA_DRIVER_OPS,
151 };
152 
153 static int tve200_probe(struct platform_device *pdev)
154 {
155 	struct device *dev = &pdev->dev;
156 	struct tve200_drm_dev_private *priv;
157 	struct drm_device *drm;
158 	struct resource *res;
159 	int irq;
160 	int ret;
161 
162 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
163 	if (!priv)
164 		return -ENOMEM;
165 
166 	drm = drm_dev_alloc(&tve200_drm_driver, dev);
167 	if (IS_ERR(drm))
168 		return PTR_ERR(drm);
169 	platform_set_drvdata(pdev, drm);
170 	priv->drm = drm;
171 	drm->dev_private = priv;
172 
173 	/* Clock the silicon so we can access the registers */
174 	priv->pclk = devm_clk_get(dev, "PCLK");
175 	if (IS_ERR(priv->pclk)) {
176 		dev_err(dev, "unable to get PCLK\n");
177 		ret = PTR_ERR(priv->pclk);
178 		goto dev_unref;
179 	}
180 	ret = clk_prepare_enable(priv->pclk);
181 	if (ret) {
182 		dev_err(dev, "failed to enable PCLK\n");
183 		goto dev_unref;
184 	}
185 
186 	/* This clock is for the pixels (27MHz) */
187 	priv->clk = devm_clk_get(dev, "TVE");
188 	if (IS_ERR(priv->clk)) {
189 		dev_err(dev, "unable to get TVE clock\n");
190 		ret = PTR_ERR(priv->clk);
191 		goto clk_disable;
192 	}
193 
194 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
195 	priv->regs = devm_ioremap_resource(dev, res);
196 	if (IS_ERR(priv->regs)) {
197 		dev_err(dev, "%s failed mmio\n", __func__);
198 		ret = -EINVAL;
199 		goto clk_disable;
200 	}
201 
202 	irq = platform_get_irq(pdev, 0);
203 	if (irq < 0) {
204 		ret = irq;
205 		goto clk_disable;
206 	}
207 
208 	/* turn off interrupts before requesting the irq */
209 	writel(0, priv->regs + TVE200_INT_EN);
210 
211 	ret = devm_request_irq(dev, irq, tve200_irq, 0, "tve200", priv);
212 	if (ret) {
213 		dev_err(dev, "failed to request irq %d\n", ret);
214 		goto clk_disable;
215 	}
216 
217 	ret = tve200_modeset_init(drm);
218 	if (ret)
219 		goto clk_disable;
220 
221 	ret = drm_dev_register(drm, 0);
222 	if (ret < 0)
223 		goto clk_disable;
224 
225 	/*
226 	 * Passing in 16 here will make the RGB565 mode the default
227 	 * Passing in 32 will use XRGB8888 mode
228 	 */
229 	drm_fbdev_generic_setup(drm, 16);
230 
231 	return 0;
232 
233 clk_disable:
234 	clk_disable_unprepare(priv->pclk);
235 dev_unref:
236 	drm_dev_put(drm);
237 	return ret;
238 }
239 
240 static int tve200_remove(struct platform_device *pdev)
241 {
242 	struct drm_device *drm = platform_get_drvdata(pdev);
243 	struct tve200_drm_dev_private *priv = drm->dev_private;
244 
245 	drm_dev_unregister(drm);
246 	if (priv->panel)
247 		drm_panel_bridge_remove(priv->bridge);
248 	drm_mode_config_cleanup(drm);
249 	clk_disable_unprepare(priv->pclk);
250 	drm_dev_put(drm);
251 
252 	return 0;
253 }
254 
255 static const struct of_device_id tve200_of_match[] = {
256 	{
257 		.compatible = "faraday,tve200",
258 	},
259 	{},
260 };
261 
262 static struct platform_driver tve200_driver = {
263 	.driver = {
264 		.name           = "tve200",
265 		.of_match_table = of_match_ptr(tve200_of_match),
266 	},
267 	.probe = tve200_probe,
268 	.remove = tve200_remove,
269 };
270 drm_module_platform_driver(tve200_driver);
271 
272 MODULE_DESCRIPTION(DRIVER_DESC);
273 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
274 MODULE_LICENSE("GPL");
275