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_helper.h>
43 #include <drm/drm_gem_dma_helper.h>
44 #include <drm/drm_gem_framebuffer_helper.h>
45 #include <drm/drm_module.h>
46 #include <drm/drm_of.h>
47 #include <drm/drm_panel.h>
48 #include <drm/drm_probe_helper.h>
49 #include <drm/drm_vblank.h>
50
51 #include "tve200_drm.h"
52
53 #define DRIVER_DESC "DRM module for Faraday TVE200"
54
55 static const struct drm_mode_config_funcs mode_config_funcs = {
56 .fb_create = drm_gem_fb_create,
57 .atomic_check = drm_atomic_helper_check,
58 .atomic_commit = drm_atomic_helper_commit,
59 };
60
tve200_modeset_init(struct drm_device * dev)61 static int tve200_modeset_init(struct drm_device *dev)
62 {
63 struct drm_mode_config *mode_config;
64 struct tve200_drm_dev_private *priv = dev->dev_private;
65 struct drm_panel *panel;
66 struct drm_bridge *bridge;
67 int ret;
68
69 drm_mode_config_init(dev);
70 mode_config = &dev->mode_config;
71 mode_config->funcs = &mode_config_funcs;
72 mode_config->min_width = 352;
73 mode_config->max_width = 720;
74 mode_config->min_height = 240;
75 mode_config->max_height = 576;
76
77 ret = drm_of_find_panel_or_bridge(dev->dev->of_node,
78 0, 0, &panel, &bridge);
79 if (ret && ret != -ENODEV)
80 return ret;
81 if (panel) {
82 bridge = drm_panel_bridge_add_typed(panel,
83 DRM_MODE_CONNECTOR_Unknown);
84 if (IS_ERR(bridge)) {
85 ret = PTR_ERR(bridge);
86 goto out_bridge;
87 }
88 } else {
89 /*
90 * TODO: when we are using a different bridge than a panel
91 * (such as a dumb VGA connector) we need to devise a different
92 * method to get the connector out of the bridge.
93 */
94 dev_err(dev->dev, "the bridge is not a panel\n");
95 ret = -EINVAL;
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_DMA_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_DMA_DRIVER_OPS,
151 };
152
tve200_probe(struct platform_device * pdev)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
tve200_remove(struct platform_device * pdev)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