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(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 = panel->connector;
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	.dumb_create = drm_gem_cma_dumb_create,
151	.gem_free_object_unlocked = drm_gem_cma_free_object,
152	.gem_vm_ops = &drm_gem_cma_vm_ops,
153
154	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
155	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
156	.gem_prime_get_sg_table	= drm_gem_cma_prime_get_sg_table,
157	.gem_prime_import_sg_table = drm_gem_cma_prime_import_sg_table,
158	.gem_prime_vmap = drm_gem_cma_prime_vmap,
159	.gem_prime_vunmap = drm_gem_cma_prime_vunmap,
160	.gem_prime_mmap = drm_gem_cma_prime_mmap,
161};
162
163static int tve200_probe(struct platform_device *pdev)
164{
165	struct device *dev = &pdev->dev;
166	struct tve200_drm_dev_private *priv;
167	struct drm_device *drm;
168	struct resource *res;
169	int irq;
170	int ret;
171
172	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
173	if (!priv)
174		return -ENOMEM;
175
176	drm = drm_dev_alloc(&tve200_drm_driver, dev);
177	if (IS_ERR(drm))
178		return PTR_ERR(drm);
179	platform_set_drvdata(pdev, drm);
180	priv->drm = drm;
181	drm->dev_private = priv;
182
183	/* Clock the silicon so we can access the registers */
184	priv->pclk = devm_clk_get(dev, "PCLK");
185	if (IS_ERR(priv->pclk)) {
186		dev_err(dev, "unable to get PCLK\n");
187		ret = PTR_ERR(priv->pclk);
188		goto dev_unref;
189	}
190	ret = clk_prepare_enable(priv->pclk);
191	if (ret) {
192		dev_err(dev, "failed to enable PCLK\n");
193		goto dev_unref;
194	}
195
196	/* This clock is for the pixels (27MHz) */
197	priv->clk = devm_clk_get(dev, "TVE");
198	if (IS_ERR(priv->clk)) {
199		dev_err(dev, "unable to get TVE clock\n");
200		ret = PTR_ERR(priv->clk);
201		goto clk_disable;
202	}
203
204	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
205	priv->regs = devm_ioremap_resource(dev, res);
206	if (IS_ERR(priv->regs)) {
207		dev_err(dev, "%s failed mmio\n", __func__);
208		ret = -EINVAL;
209		goto clk_disable;
210	}
211
212	irq = platform_get_irq(pdev, 0);
213	if (!irq) {
214		ret = -EINVAL;
215		goto clk_disable;
216	}
217
218	/* turn off interrupts before requesting the irq */
219	writel(0, priv->regs + TVE200_INT_EN);
220
221	ret = devm_request_irq(dev, irq, tve200_irq, 0, "tve200", priv);
222	if (ret) {
223		dev_err(dev, "failed to request irq %d\n", ret);
224		goto clk_disable;
225	}
226
227	ret = tve200_modeset_init(drm);
228	if (ret)
229		goto clk_disable;
230
231	ret = drm_dev_register(drm, 0);
232	if (ret < 0)
233		goto clk_disable;
234
235	/*
236	 * Passing in 16 here will make the RGB565 mode the default
237	 * Passing in 32 will use XRGB8888 mode
238	 */
239	drm_fbdev_generic_setup(drm, 16);
240
241	return 0;
242
243clk_disable:
244	clk_disable_unprepare(priv->pclk);
245dev_unref:
246	drm_dev_put(drm);
247	return ret;
248}
249
250static int tve200_remove(struct platform_device *pdev)
251{
252	struct drm_device *drm = platform_get_drvdata(pdev);
253	struct tve200_drm_dev_private *priv = drm->dev_private;
254
255	drm_dev_unregister(drm);
256	if (priv->panel)
257		drm_panel_bridge_remove(priv->bridge);
258	drm_mode_config_cleanup(drm);
259	clk_disable_unprepare(priv->pclk);
260	drm_dev_put(drm);
261
262	return 0;
263}
264
265static const struct of_device_id tve200_of_match[] = {
266	{
267		.compatible = "faraday,tve200",
268	},
269	{},
270};
271
272static struct platform_driver tve200_driver = {
273	.driver = {
274		.name           = "tve200",
275		.of_match_table = of_match_ptr(tve200_of_match),
276	},
277	.probe = tve200_probe,
278	.remove = tve200_remove,
279};
280module_platform_driver(tve200_driver);
281
282MODULE_DESCRIPTION(DRIVER_DESC);
283MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
284MODULE_LICENSE("GPL");