1 /*
2  * Copyright (C) 2017 Linus Walleij <linus.walleij@linaro.org>
3  * Parts of this file were based on sources as follows:
4  *
5  * Copyright (C) 2006-2008 Intel Corporation
6  * Copyright (C) 2007 Amos Lee <amos_lee@storlinksemi.com>
7  * Copyright (C) 2007 Dave Airlie <airlied@linux.ie>
8  * Copyright (C) 2011 Texas Instruments
9  * Copyright (C) 2017 Eric Anholt
10  *
11  * This program is free software and is provided to you under the terms of the
12  * GNU General Public License version 2 as published by the Free Software
13  * Foundation, and any use by you of this program is subject to the terms of
14  * such GNU licence.
15  */
16 
17 /**
18  * DOC: Faraday TV Encoder TVE200 DRM Driver
19  *
20  * The Faraday TV Encoder TVE200 is also known as the Gemini TV Interface
21  * Controller (TVC) and is found in the Gemini Chipset from Storlink
22  * Semiconductor (later Storm Semiconductor, later Cortina Systems)
23  * but also in the Grain Media GM8180 chipset. On the Gemini the module
24  * is connected to 8 data lines and a single clock line, comprising an
25  * 8-bit BT.656 interface.
26  *
27  * This is a very basic YUV display driver. The datasheet specifies that
28  * it supports the ITU BT.656 standard. It requires a 27 MHz clock which is
29  * the hallmark of any TV encoder supporting both PAL and NTSC.
30  *
31  * This driver exposes a standard KMS interface for this TV encoder.
32  */
33 
34 #include <linux/clk.h>
35 #include <linux/dma-buf.h>
36 #include <linux/irq.h>
37 #include <linux/io.h>
38 #include <linux/module.h>
39 #include <linux/platform_device.h>
40 #include <linux/shmem_fs.h>
41 #include <linux/slab.h>
42 #include <linux/version.h>
43 
44 #include <drm/drmP.h>
45 #include <drm/drm_atomic_helper.h>
46 #include <drm/drm_crtc_helper.h>
47 #include <drm/drm_gem_cma_helper.h>
48 #include <drm/drm_gem_framebuffer_helper.h>
49 #include <drm/drm_fb_cma_helper.h>
50 #include <drm/drm_panel.h>
51 #include <drm/drm_of.h>
52 #include <drm/drm_bridge.h>
53 
54 #include "tve200_drm.h"
55 
56 #define DRIVER_DESC      "DRM module for Faraday TVE200"
57 
58 static const struct drm_mode_config_funcs mode_config_funcs = {
59 	.fb_create = drm_gem_fb_create,
60 	.atomic_check = drm_atomic_helper_check,
61 	.atomic_commit = drm_atomic_helper_commit,
62 };
63 
64 static int tve200_modeset_init(struct drm_device *dev)
65 {
66 	struct drm_mode_config *mode_config;
67 	struct tve200_drm_dev_private *priv = dev->dev_private;
68 	struct drm_panel *panel;
69 	struct drm_bridge *bridge;
70 	int ret = 0;
71 
72 	drm_mode_config_init(dev);
73 	mode_config = &dev->mode_config;
74 	mode_config->funcs = &mode_config_funcs;
75 	mode_config->min_width = 352;
76 	mode_config->max_width = 720;
77 	mode_config->min_height = 240;
78 	mode_config->max_height = 576;
79 
80 	ret = drm_of_find_panel_or_bridge(dev->dev->of_node,
81 					  0, 0, &panel, &bridge);
82 	if (ret && ret != -ENODEV)
83 		return ret;
84 	if (panel) {
85 		bridge = drm_panel_bridge_add(panel,
86 					      DRM_MODE_CONNECTOR_Unknown);
87 		if (IS_ERR(bridge)) {
88 			ret = PTR_ERR(bridge);
89 			goto out_bridge;
90 		}
91 	} else {
92 		/*
93 		 * TODO: when we are using a different bridge than a panel
94 		 * (such as a dumb VGA connector) we need to devise a different
95 		 * method to get the connector out of the bridge.
96 		 */
97 		dev_err(dev->dev, "the bridge is not a panel\n");
98 		goto out_bridge;
99 	}
100 
101 	ret = tve200_display_init(dev);
102 	if (ret) {
103 		dev_err(dev->dev, "failed to init display\n");
104 		goto out_bridge;
105 	}
106 
107 	ret = drm_simple_display_pipe_attach_bridge(&priv->pipe,
108 						    bridge);
109 	if (ret) {
110 		dev_err(dev->dev, "failed to attach bridge\n");
111 		goto out_bridge;
112 	}
113 
114 	priv->panel = panel;
115 	priv->connector = panel->connector;
116 	priv->bridge = bridge;
117 
118 	dev_info(dev->dev, "attached to panel %s\n",
119 		 dev_name(panel->dev));
120 
121 	ret = drm_vblank_init(dev, 1);
122 	if (ret) {
123 		dev_err(dev->dev, "failed to init vblank\n");
124 		goto out_bridge;
125 	}
126 
127 	drm_mode_config_reset(dev);
128 
129 	/*
130 	 * Passing in 16 here will make the RGB656 mode the default
131 	 * Passing in 32 will use XRGB8888 mode
132 	 */
133 	priv->fbdev = drm_fbdev_cma_init(dev, 16,
134 					 dev->mode_config.num_connector);
135 	drm_kms_helper_poll_init(dev);
136 
137 	goto finish;
138 
139 out_bridge:
140 	if (panel)
141 		drm_panel_bridge_remove(bridge);
142 	drm_mode_config_cleanup(dev);
143 finish:
144 	return ret;
145 }
146 
147 DEFINE_DRM_GEM_CMA_FOPS(drm_fops);
148 
149 static void tve200_lastclose(struct drm_device *dev)
150 {
151 	struct tve200_drm_dev_private *priv = dev->dev_private;
152 
153 	drm_fbdev_cma_restore_mode(priv->fbdev);
154 }
155 
156 static struct drm_driver tve200_drm_driver = {
157 	.driver_features =
158 		DRIVER_MODESET | DRIVER_GEM | DRIVER_PRIME | DRIVER_ATOMIC,
159 	.lastclose = tve200_lastclose,
160 	.ioctls = NULL,
161 	.fops = &drm_fops,
162 	.name = "tve200",
163 	.desc = DRIVER_DESC,
164 	.date = "20170703",
165 	.major = 1,
166 	.minor = 0,
167 	.patchlevel = 0,
168 	.dumb_create = drm_gem_cma_dumb_create,
169 	.gem_free_object_unlocked = drm_gem_cma_free_object,
170 	.gem_vm_ops = &drm_gem_cma_vm_ops,
171 
172 	.enable_vblank = tve200_enable_vblank,
173 	.disable_vblank = tve200_disable_vblank,
174 
175 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
176 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
177 	.gem_prime_import = drm_gem_prime_import,
178 	.gem_prime_export = drm_gem_prime_export,
179 	.gem_prime_get_sg_table	= drm_gem_cma_prime_get_sg_table,
180 	.gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
181 	.gem_prime_vmap = drm_gem_cma_prime_vmap,
182 	.gem_prime_vunmap = drm_gem_cma_prime_vunmap,
183 	.gem_prime_mmap = drm_gem_cma_prime_mmap,
184 };
185 
186 static int tve200_probe(struct platform_device *pdev)
187 {
188 	struct device *dev = &pdev->dev;
189 	struct tve200_drm_dev_private *priv;
190 	struct drm_device *drm;
191 	struct resource *res;
192 	int irq;
193 	int ret;
194 
195 	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
196 	if (!priv)
197 		return -ENOMEM;
198 
199 	drm = drm_dev_alloc(&tve200_drm_driver, dev);
200 	if (IS_ERR(drm))
201 		return PTR_ERR(drm);
202 	platform_set_drvdata(pdev, drm);
203 	priv->drm = drm;
204 	drm->dev_private = priv;
205 
206 	/* Clock the silicon so we can access the registers */
207 	priv->pclk = devm_clk_get(dev, "PCLK");
208 	if (IS_ERR(priv->pclk)) {
209 		dev_err(dev, "unable to get PCLK\n");
210 		ret = PTR_ERR(priv->pclk);
211 		goto dev_unref;
212 	}
213 	ret = clk_prepare_enable(priv->pclk);
214 	if (ret) {
215 		dev_err(dev, "failed to enable PCLK\n");
216 		goto dev_unref;
217 	}
218 
219 	/* This clock is for the pixels (27MHz) */
220 	priv->clk = devm_clk_get(dev, "TVE");
221 	if (IS_ERR(priv->clk)) {
222 		dev_err(dev, "unable to get TVE clock\n");
223 		ret = PTR_ERR(priv->clk);
224 		goto clk_disable;
225 	}
226 
227 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
228 	priv->regs = devm_ioremap_resource(dev, res);
229 	if (IS_ERR(priv->regs)) {
230 		dev_err(dev, "%s failed mmio\n", __func__);
231 		ret = -EINVAL;
232 		goto clk_disable;
233 	}
234 
235 	irq = platform_get_irq(pdev, 0);
236 	if (!irq) {
237 		ret = -EINVAL;
238 		goto clk_disable;
239 	}
240 
241 	/* turn off interrupts before requesting the irq */
242 	writel(0, priv->regs + TVE200_INT_EN);
243 
244 	ret = devm_request_irq(dev, irq, tve200_irq, 0, "tve200", priv);
245 	if (ret) {
246 		dev_err(dev, "failed to request irq %d\n", ret);
247 		goto clk_disable;
248 	}
249 
250 	ret = tve200_modeset_init(drm);
251 	if (ret)
252 		goto clk_disable;
253 
254 	ret = drm_dev_register(drm, 0);
255 	if (ret < 0)
256 		goto clk_disable;
257 
258 	return 0;
259 
260 clk_disable:
261 	clk_disable_unprepare(priv->pclk);
262 dev_unref:
263 	drm_dev_unref(drm);
264 	return ret;
265 }
266 
267 static int tve200_remove(struct platform_device *pdev)
268 {
269 	struct drm_device *drm = platform_get_drvdata(pdev);
270 	struct tve200_drm_dev_private *priv = drm->dev_private;
271 
272 	drm_dev_unregister(drm);
273 	if (priv->fbdev)
274 		drm_fbdev_cma_fini(priv->fbdev);
275 	if (priv->panel)
276 		drm_panel_bridge_remove(priv->bridge);
277 	drm_mode_config_cleanup(drm);
278 	clk_disable_unprepare(priv->pclk);
279 	drm_dev_unref(drm);
280 
281 	return 0;
282 }
283 
284 static const struct of_device_id tve200_of_match[] = {
285 	{
286 		.compatible = "faraday,tve200",
287 	},
288 	{},
289 };
290 
291 static struct platform_driver tve200_driver = {
292 	.driver = {
293 		.name           = "tve200",
294 		.of_match_table = of_match_ptr(tve200_of_match),
295 	},
296 	.probe = tve200_probe,
297 	.remove = tve200_remove,
298 };
299 module_platform_driver(tve200_driver);
300 
301 MODULE_DESCRIPTION(DRIVER_DESC);
302 MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
303 MODULE_LICENSE("GPL");
304