xref: /openbmc/linux/drivers/gpu/drm/sun4i/sun8i_tcon_top.c (revision ba61bb17496d1664bf7c5c2fd650d5fd78bd0a92)
1 // SPDX-License-Identifier: GPL-2.0+
2 /* Copyright (c) 2018 Jernej Skrabec <jernej.skrabec@siol.net> */
3 
4 #include <drm/drmP.h>
5 
6 #include <dt-bindings/clock/sun8i-tcon-top.h>
7 
8 #include <linux/bitfield.h>
9 #include <linux/component.h>
10 #include <linux/device.h>
11 #include <linux/module.h>
12 #include <linux/of_graph.h>
13 #include <linux/platform_device.h>
14 
15 #include "sun8i_tcon_top.h"
16 
17 static int sun8i_tcon_top_get_connected_ep_id(struct device_node *node,
18 					      int port_id)
19 {
20 	struct device_node *ep, *remote, *port;
21 	struct of_endpoint endpoint;
22 
23 	port = of_graph_get_port_by_id(node, port_id);
24 	if (!port)
25 		return -ENOENT;
26 
27 	for_each_available_child_of_node(port, ep) {
28 		remote = of_graph_get_remote_port_parent(ep);
29 		if (!remote)
30 			continue;
31 
32 		if (of_device_is_available(remote)) {
33 			of_graph_parse_endpoint(ep, &endpoint);
34 
35 			of_node_put(remote);
36 
37 			return endpoint.id;
38 		}
39 
40 		of_node_put(remote);
41 	}
42 
43 	return -ENOENT;
44 }
45 
46 static struct clk_hw *sun8i_tcon_top_register_gate(struct device *dev,
47 						   struct clk *parent,
48 						   void __iomem *regs,
49 						   spinlock_t *lock,
50 						   u8 bit, int name_index)
51 {
52 	const char *clk_name, *parent_name;
53 	int ret;
54 
55 	parent_name = __clk_get_name(parent);
56 	ret = of_property_read_string_index(dev->of_node,
57 					    "clock-output-names", name_index,
58 					    &clk_name);
59 	if (ret)
60 		return ERR_PTR(ret);
61 
62 	return clk_hw_register_gate(dev, clk_name, parent_name,
63 				    CLK_SET_RATE_PARENT,
64 				    regs + TCON_TOP_GATE_SRC_REG,
65 				    bit, 0, lock);
66 };
67 
68 static int sun8i_tcon_top_bind(struct device *dev, struct device *master,
69 			       void *data)
70 {
71 	struct platform_device *pdev = to_platform_device(dev);
72 	struct clk *dsi, *tcon_tv0, *tcon_tv1, *tve0, *tve1;
73 	struct clk_hw_onecell_data *clk_data;
74 	struct sun8i_tcon_top *tcon_top;
75 	bool mixer0_unused = false;
76 	struct resource *res;
77 	void __iomem *regs;
78 	int ret, i, id;
79 	u32 val;
80 
81 	tcon_top = devm_kzalloc(dev, sizeof(*tcon_top), GFP_KERNEL);
82 	if (!tcon_top)
83 		return -ENOMEM;
84 
85 	clk_data = devm_kzalloc(dev, sizeof(*clk_data) +
86 				sizeof(*clk_data->hws) * CLK_NUM,
87 				GFP_KERNEL);
88 	if (!clk_data)
89 		return -ENOMEM;
90 	tcon_top->clk_data = clk_data;
91 
92 	spin_lock_init(&tcon_top->reg_lock);
93 
94 	tcon_top->rst = devm_reset_control_get(dev, NULL);
95 	if (IS_ERR(tcon_top->rst)) {
96 		dev_err(dev, "Couldn't get our reset line\n");
97 		return PTR_ERR(tcon_top->rst);
98 	}
99 
100 	tcon_top->bus = devm_clk_get(dev, "bus");
101 	if (IS_ERR(tcon_top->bus)) {
102 		dev_err(dev, "Couldn't get the bus clock\n");
103 		return PTR_ERR(tcon_top->bus);
104 	}
105 
106 	dsi = devm_clk_get(dev, "dsi");
107 	if (IS_ERR(dsi)) {
108 		dev_err(dev, "Couldn't get the dsi clock\n");
109 		return PTR_ERR(dsi);
110 	}
111 
112 	tcon_tv0 = devm_clk_get(dev, "tcon-tv0");
113 	if (IS_ERR(tcon_tv0)) {
114 		dev_err(dev, "Couldn't get the tcon-tv0 clock\n");
115 		return PTR_ERR(tcon_tv0);
116 	}
117 
118 	tcon_tv1 = devm_clk_get(dev, "tcon-tv1");
119 	if (IS_ERR(tcon_tv1)) {
120 		dev_err(dev, "Couldn't get the tcon-tv1 clock\n");
121 		return PTR_ERR(tcon_tv1);
122 	}
123 
124 	tve0 = devm_clk_get(dev, "tve0");
125 	if (IS_ERR(tve0)) {
126 		dev_err(dev, "Couldn't get the tve0 clock\n");
127 		return PTR_ERR(tve0);
128 	}
129 
130 	tve1 = devm_clk_get(dev, "tve1");
131 	if (IS_ERR(tve1)) {
132 		dev_err(dev, "Couldn't get the tve1 clock\n");
133 		return PTR_ERR(tve1);
134 	}
135 
136 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
137 	regs = devm_ioremap_resource(dev, res);
138 	if (IS_ERR(regs))
139 		return PTR_ERR(regs);
140 
141 	ret = reset_control_deassert(tcon_top->rst);
142 	if (ret) {
143 		dev_err(dev, "Could not deassert ctrl reset control\n");
144 		return ret;
145 	}
146 
147 	ret = clk_prepare_enable(tcon_top->bus);
148 	if (ret) {
149 		dev_err(dev, "Could not enable bus clock\n");
150 		goto err_assert_reset;
151 	}
152 
153 	val = 0;
154 
155 	/* check if HDMI mux output is connected */
156 	if (sun8i_tcon_top_get_connected_ep_id(dev->of_node, 5) >= 0) {
157 		/* find HDMI input endpoint id, if it is connected at all*/
158 		id = sun8i_tcon_top_get_connected_ep_id(dev->of_node, 4);
159 		if (id >= 0)
160 			val = FIELD_PREP(TCON_TOP_HDMI_SRC_MSK, id + 1);
161 		else
162 			DRM_DEBUG_DRIVER("TCON TOP HDMI input is not connected\n");
163 	} else {
164 		DRM_DEBUG_DRIVER("TCON TOP HDMI output is not connected\n");
165 	}
166 
167 	writel(val, regs + TCON_TOP_GATE_SRC_REG);
168 
169 	val = 0;
170 
171 	/* process mixer0 mux output */
172 	id = sun8i_tcon_top_get_connected_ep_id(dev->of_node, 1);
173 	if (id >= 0) {
174 		val = FIELD_PREP(TCON_TOP_PORT_DE0_MSK, id);
175 	} else {
176 		DRM_DEBUG_DRIVER("TCON TOP mixer0 output is not connected\n");
177 		mixer0_unused = true;
178 	}
179 
180 	/* process mixer1 mux output */
181 	id = sun8i_tcon_top_get_connected_ep_id(dev->of_node, 3);
182 	if (id >= 0) {
183 		val |= FIELD_PREP(TCON_TOP_PORT_DE1_MSK, id);
184 
185 		/*
186 		 * mixer0 mux has priority over mixer1 mux. We have to
187 		 * make sure mixer0 doesn't overtake TCON from mixer1.
188 		 */
189 		if (mixer0_unused && id == 0)
190 			val |= FIELD_PREP(TCON_TOP_PORT_DE0_MSK, 1);
191 	} else {
192 		DRM_DEBUG_DRIVER("TCON TOP mixer1 output is not connected\n");
193 	}
194 
195 	writel(val, regs + TCON_TOP_PORT_SEL_REG);
196 
197 	/*
198 	 * TCON TOP has two muxes, which select parent clock for each TCON TV
199 	 * channel clock. Parent could be either TCON TV or TVE clock. For now
200 	 * we leave this fixed to TCON TV, since TVE driver for R40 is not yet
201 	 * implemented. Once it is, graph needs to be traversed to determine
202 	 * if TVE is active on each TCON TV. If it is, mux should be switched
203 	 * to TVE clock parent.
204 	 */
205 	clk_data->hws[CLK_TCON_TOP_TV0] =
206 		sun8i_tcon_top_register_gate(dev, tcon_tv0, regs,
207 					     &tcon_top->reg_lock,
208 					     TCON_TOP_TCON_TV0_GATE, 0);
209 
210 	clk_data->hws[CLK_TCON_TOP_TV1] =
211 		sun8i_tcon_top_register_gate(dev, tcon_tv1, regs,
212 					     &tcon_top->reg_lock,
213 					     TCON_TOP_TCON_TV1_GATE, 1);
214 
215 	clk_data->hws[CLK_TCON_TOP_DSI] =
216 		sun8i_tcon_top_register_gate(dev, dsi, regs,
217 					     &tcon_top->reg_lock,
218 					     TCON_TOP_TCON_DSI_GATE, 2);
219 
220 	for (i = 0; i < CLK_NUM; i++)
221 		if (IS_ERR(clk_data->hws[i])) {
222 			ret = PTR_ERR(clk_data->hws[i]);
223 			goto err_unregister_gates;
224 		}
225 
226 	clk_data->num = CLK_NUM;
227 
228 	ret = of_clk_add_hw_provider(dev->of_node, of_clk_hw_onecell_get,
229 				     clk_data);
230 	if (ret)
231 		goto err_unregister_gates;
232 
233 	dev_set_drvdata(dev, tcon_top);
234 
235 	return 0;
236 
237 err_unregister_gates:
238 	for (i = 0; i < CLK_NUM; i++)
239 		if (clk_data->hws[i])
240 			clk_hw_unregister_gate(clk_data->hws[i]);
241 	clk_disable_unprepare(tcon_top->bus);
242 err_assert_reset:
243 	reset_control_assert(tcon_top->rst);
244 
245 	return ret;
246 }
247 
248 static void sun8i_tcon_top_unbind(struct device *dev, struct device *master,
249 				  void *data)
250 {
251 	struct sun8i_tcon_top *tcon_top = dev_get_drvdata(dev);
252 	struct clk_hw_onecell_data *clk_data = tcon_top->clk_data;
253 	int i;
254 
255 	of_clk_del_provider(dev->of_node);
256 	for (i = 0; i < CLK_NUM; i++)
257 		clk_hw_unregister_gate(clk_data->hws[i]);
258 
259 	clk_disable_unprepare(tcon_top->bus);
260 	reset_control_assert(tcon_top->rst);
261 }
262 
263 static const struct component_ops sun8i_tcon_top_ops = {
264 	.bind	= sun8i_tcon_top_bind,
265 	.unbind	= sun8i_tcon_top_unbind,
266 };
267 
268 static int sun8i_tcon_top_probe(struct platform_device *pdev)
269 {
270 	return component_add(&pdev->dev, &sun8i_tcon_top_ops);
271 }
272 
273 static int sun8i_tcon_top_remove(struct platform_device *pdev)
274 {
275 	component_del(&pdev->dev, &sun8i_tcon_top_ops);
276 
277 	return 0;
278 }
279 
280 /* sun4i_drv uses this list to check if a device node is a TCON TOP */
281 const struct of_device_id sun8i_tcon_top_of_table[] = {
282 	{ .compatible = "allwinner,sun8i-r40-tcon-top" },
283 	{ /* sentinel */ }
284 };
285 MODULE_DEVICE_TABLE(of, sun8i_tcon_top_of_table);
286 EXPORT_SYMBOL(sun8i_tcon_top_of_table);
287 
288 static struct platform_driver sun8i_tcon_top_platform_driver = {
289 	.probe		= sun8i_tcon_top_probe,
290 	.remove		= sun8i_tcon_top_remove,
291 	.driver		= {
292 		.name		= "sun8i-tcon-top",
293 		.of_match_table	= sun8i_tcon_top_of_table,
294 	},
295 };
296 module_platform_driver(sun8i_tcon_top_platform_driver);
297 
298 MODULE_AUTHOR("Jernej Skrabec <jernej.skrabec@siol.net>");
299 MODULE_DESCRIPTION("Allwinner R40 TCON TOP driver");
300 MODULE_LICENSE("GPL");
301