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#include <linux/version.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_fb_cma_helper.h>
44#include <drm/drm_fb_helper.h>
45#include <drm/drm_gem_cma_helper.h>
46#include <drm/drm_gem_framebuffer_helper.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
56static 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
62static 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
130out_bridge:
131	if (panel)
132		drm_panel_bridge_remove(bridge);
133	drm_mode_config_cleanup(dev);
134finish:
135	return ret;
136}
137
138DEFINE_DRM_GEM_CMA_FOPS(drm_fops);
139
140static 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
153static 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
233clk_disable:
234	clk_disable_unprepare(priv->pclk);
235dev_unref:
236	drm_dev_put(drm);
237	return ret;
238}
239
240static 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
255static const struct of_device_id tve200_of_match[] = {
256	{
257		.compatible = "faraday,tve200",
258	},
259	{},
260};
261
262static 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};
270module_platform_driver(tve200_driver);
271
272MODULE_DESCRIPTION(DRIVER_DESC);
273MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
274MODULE_LICENSE("GPL");
275