1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * shmob_drm_drv.c  --  SH Mobile DRM driver
4  *
5  * Copyright (C) 2012 Renesas Electronics Corporation
6  *
7  * Laurent Pinchart (laurent.pinchart@ideasonboard.com)
8  */
9 
10 #include <linux/clk.h>
11 #include <linux/io.h>
12 #include <linux/mm.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/platform_device.h>
16 #include <linux/pm.h>
17 #include <linux/pm_runtime.h>
18 #include <linux/slab.h>
19 
20 #include <drm/drm_atomic_helper.h>
21 #include <drm/drm_drv.h>
22 #include <drm/drm_fbdev_generic.h>
23 #include <drm/drm_gem_dma_helper.h>
24 #include <drm/drm_modeset_helper.h>
25 #include <drm/drm_module.h>
26 #include <drm/drm_probe_helper.h>
27 #include <drm/drm_vblank.h>
28 
29 #include "shmob_drm_drv.h"
30 #include "shmob_drm_kms.h"
31 #include "shmob_drm_plane.h"
32 #include "shmob_drm_regs.h"
33 
34 /* -----------------------------------------------------------------------------
35  * Hardware initialization
36  */
37 
38 static int shmob_drm_setup_clocks(struct shmob_drm_device *sdev,
39 				  enum shmob_drm_clk_source clksrc)
40 {
41 	struct clk *clk;
42 	char *clkname;
43 
44 	switch (clksrc) {
45 	case SHMOB_DRM_CLK_BUS:
46 		clkname = "fck";
47 		sdev->lddckr = LDDCKR_ICKSEL_BUS;
48 		break;
49 	case SHMOB_DRM_CLK_PERIPHERAL:
50 		clkname = "media";
51 		sdev->lddckr = LDDCKR_ICKSEL_MIPI;
52 		break;
53 	case SHMOB_DRM_CLK_EXTERNAL:
54 		clkname = "lclk";
55 		sdev->lddckr = LDDCKR_ICKSEL_HDMI;
56 		break;
57 	default:
58 		return -EINVAL;
59 	}
60 
61 	clk = devm_clk_get(sdev->dev, clkname);
62 	if (IS_ERR(clk)) {
63 		dev_err(sdev->dev, "cannot get dot clock %s\n", clkname);
64 		return PTR_ERR(clk);
65 	}
66 
67 	sdev->clock = clk;
68 	return 0;
69 }
70 
71 /* -----------------------------------------------------------------------------
72  * DRM operations
73  */
74 
75 static irqreturn_t shmob_drm_irq(int irq, void *arg)
76 {
77 	struct drm_device *dev = arg;
78 	struct shmob_drm_device *sdev = to_shmob_device(dev);
79 	unsigned long flags;
80 	u32 status;
81 
82 	/* Acknowledge interrupts. Putting interrupt enable and interrupt flag
83 	 * bits in the same register is really brain-dead design and requires
84 	 * taking a spinlock.
85 	 */
86 	spin_lock_irqsave(&sdev->irq_lock, flags);
87 	status = lcdc_read(sdev, LDINTR);
88 	lcdc_write(sdev, LDINTR, status ^ LDINTR_STATUS_MASK);
89 	spin_unlock_irqrestore(&sdev->irq_lock, flags);
90 
91 	if (status & LDINTR_VES) {
92 		drm_crtc_handle_vblank(&sdev->crtc.base);
93 		shmob_drm_crtc_finish_page_flip(&sdev->crtc);
94 	}
95 
96 	return IRQ_HANDLED;
97 }
98 
99 DEFINE_DRM_GEM_DMA_FOPS(shmob_drm_fops);
100 
101 static const struct drm_driver shmob_drm_driver = {
102 	.driver_features	= DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
103 	DRM_GEM_DMA_DRIVER_OPS,
104 	.fops			= &shmob_drm_fops,
105 	.name			= "shmob-drm",
106 	.desc			= "Renesas SH Mobile DRM",
107 	.date			= "20120424",
108 	.major			= 1,
109 	.minor			= 0,
110 };
111 
112 /* -----------------------------------------------------------------------------
113  * Power management
114  */
115 
116 static int shmob_drm_pm_suspend(struct device *dev)
117 {
118 	struct shmob_drm_device *sdev = dev_get_drvdata(dev);
119 
120 	return drm_mode_config_helper_suspend(&sdev->ddev);
121 }
122 
123 static int shmob_drm_pm_resume(struct device *dev)
124 {
125 	struct shmob_drm_device *sdev = dev_get_drvdata(dev);
126 
127 	return drm_mode_config_helper_resume(&sdev->ddev);
128 }
129 
130 static int shmob_drm_pm_runtime_suspend(struct device *dev)
131 {
132 	struct shmob_drm_device *sdev = dev_get_drvdata(dev);
133 
134 	if (sdev->clock)
135 		clk_disable_unprepare(sdev->clock);
136 
137 	return 0;
138 }
139 
140 static int shmob_drm_pm_runtime_resume(struct device *dev)
141 {
142 	struct shmob_drm_device *sdev = dev_get_drvdata(dev);
143 	int ret;
144 
145 	if (sdev->clock) {
146 		ret = clk_prepare_enable(sdev->clock);
147 		if (ret < 0)
148 			return ret;
149 	}
150 
151 	return 0;
152 }
153 
154 static const struct dev_pm_ops shmob_drm_pm_ops = {
155 	SYSTEM_SLEEP_PM_OPS(shmob_drm_pm_suspend, shmob_drm_pm_resume)
156 	RUNTIME_PM_OPS(shmob_drm_pm_runtime_suspend,
157 		       shmob_drm_pm_runtime_resume, NULL)
158 };
159 
160 /* -----------------------------------------------------------------------------
161  * Platform driver
162  */
163 
164 static void shmob_drm_remove(struct platform_device *pdev)
165 {
166 	struct shmob_drm_device *sdev = platform_get_drvdata(pdev);
167 	struct drm_device *ddev = &sdev->ddev;
168 
169 	drm_dev_unregister(ddev);
170 	drm_atomic_helper_shutdown(ddev);
171 	drm_kms_helper_poll_fini(ddev);
172 }
173 
174 static int shmob_drm_probe(struct platform_device *pdev)
175 {
176 	struct shmob_drm_platform_data *pdata = pdev->dev.platform_data;
177 	const struct shmob_drm_config *config;
178 	struct shmob_drm_device *sdev;
179 	struct drm_device *ddev;
180 	int ret;
181 
182 	config = of_device_get_match_data(&pdev->dev);
183 	if (!config && !pdata) {
184 		dev_err(&pdev->dev, "no platform data\n");
185 		return -EINVAL;
186 	}
187 
188 	/*
189 	 * Allocate and initialize the DRM device, driver private data, I/O
190 	 * resources and clocks.
191 	 */
192 	sdev = devm_drm_dev_alloc(&pdev->dev, &shmob_drm_driver,
193 				  struct shmob_drm_device, ddev);
194 	if (IS_ERR(sdev))
195 		return PTR_ERR(sdev);
196 
197 	ddev = &sdev->ddev;
198 	sdev->dev = &pdev->dev;
199 	if (config) {
200 		sdev->config = *config;
201 	} else {
202 		sdev->pdata = pdata;
203 		sdev->config.clk_source = pdata->clk_source;
204 		sdev->config.clk_div = pdata->iface.clk_div;
205 	}
206 	spin_lock_init(&sdev->irq_lock);
207 
208 	platform_set_drvdata(pdev, sdev);
209 
210 	sdev->mmio = devm_platform_ioremap_resource(pdev, 0);
211 	if (IS_ERR(sdev->mmio))
212 		return PTR_ERR(sdev->mmio);
213 
214 	ret = shmob_drm_setup_clocks(sdev, sdev->config.clk_source);
215 	if (ret < 0)
216 		return ret;
217 
218 	ret = devm_pm_runtime_enable(&pdev->dev);
219 	if (ret)
220 		return ret;
221 
222 	ret = drm_vblank_init(ddev, 1);
223 	if (ret < 0) {
224 		dev_err(&pdev->dev, "failed to initialize vblank\n");
225 		return ret;
226 	}
227 
228 	ret = shmob_drm_modeset_init(sdev);
229 	if (ret < 0)
230 		return dev_err_probe(&pdev->dev, ret,
231 				     "failed to initialize mode setting\n");
232 
233 	ret = platform_get_irq(pdev, 0);
234 	if (ret < 0)
235 		goto err_modeset_cleanup;
236 	sdev->irq = ret;
237 
238 	ret = devm_request_irq(&pdev->dev, sdev->irq, shmob_drm_irq, 0,
239 			       ddev->driver->name, ddev);
240 	if (ret < 0) {
241 		dev_err(&pdev->dev, "failed to install IRQ handler\n");
242 		goto err_modeset_cleanup;
243 	}
244 
245 	/*
246 	 * Register the DRM device with the core and the connectors with
247 	 * sysfs.
248 	 */
249 	ret = drm_dev_register(ddev, 0);
250 	if (ret < 0)
251 		goto err_modeset_cleanup;
252 
253 	drm_fbdev_generic_setup(ddev, 16);
254 
255 	return 0;
256 
257 err_modeset_cleanup:
258 	drm_kms_helper_poll_fini(ddev);
259 	return ret;
260 }
261 
262 static const struct shmob_drm_config shmob_arm_config = {
263 	.clk_source = SHMOB_DRM_CLK_BUS,
264 	.clk_div = 5,
265 };
266 
267 static const struct of_device_id shmob_drm_of_table[] __maybe_unused = {
268 	{ .compatible = "renesas,r8a7740-lcdc",	.data = &shmob_arm_config, },
269 	{ .compatible = "renesas,sh73a0-lcdc",	.data = &shmob_arm_config, },
270 	{ /* sentinel */ }
271 };
272 
273 static struct platform_driver shmob_drm_platform_driver = {
274 	.probe		= shmob_drm_probe,
275 	.remove_new	= shmob_drm_remove,
276 	.driver		= {
277 		.name	= "shmob-drm",
278 		.of_match_table = of_match_ptr(shmob_drm_of_table),
279 		.pm	= &shmob_drm_pm_ops,
280 	},
281 };
282 
283 drm_module_platform_driver(shmob_drm_platform_driver);
284 
285 MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@ideasonboard.com>");
286 MODULE_DESCRIPTION("Renesas SH Mobile DRM Driver");
287 MODULE_LICENSE("GPL");
288