1 // SPDX-License-Identifier: GPL-2.0+
2 //
3 // Copyright 2012 Freescale Semiconductor, Inc.
4 // Copyright 2012 Linaro Ltd.
5 // Copyright 2009 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
6 //
7 // Initial development of this code was funded by
8 // Phytec Messtechnik GmbH, http://www.phytec.de
9 
10 #include <linux/clk.h>
11 #include <linux/debugfs.h>
12 #include <linux/err.h>
13 #include <linux/io.h>
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/of_device.h>
17 #include <linux/platform_device.h>
18 #include <linux/slab.h>
19 
20 #include "imx-audmux.h"
21 
22 #define DRIVER_NAME "imx-audmux"
23 
24 static struct clk *audmux_clk;
25 static void __iomem *audmux_base;
26 static u32 *regcache;
27 static u32 reg_max;
28 
29 #define IMX_AUDMUX_V2_PTCR(x)		((x) * 8)
30 #define IMX_AUDMUX_V2_PDCR(x)		((x) * 8 + 4)
31 
32 #ifdef CONFIG_DEBUG_FS
33 static struct dentry *audmux_debugfs_root;
34 
35 /* There is an annoying discontinuity in the SSI numbering with regard
36  * to the Linux number of the devices */
audmux_port_string(int port)37 static const char *audmux_port_string(int port)
38 {
39 	switch (port) {
40 	case MX31_AUDMUX_PORT1_SSI0:
41 		return "imx-ssi.0";
42 	case MX31_AUDMUX_PORT2_SSI1:
43 		return "imx-ssi.1";
44 	case MX31_AUDMUX_PORT3_SSI_PINS_3:
45 		return "SSI3";
46 	case MX31_AUDMUX_PORT4_SSI_PINS_4:
47 		return "SSI4";
48 	case MX31_AUDMUX_PORT5_SSI_PINS_5:
49 		return "SSI5";
50 	case MX31_AUDMUX_PORT6_SSI_PINS_6:
51 		return "SSI6";
52 	default:
53 		return "UNKNOWN";
54 	}
55 }
56 
audmux_read_file(struct file * file,char __user * user_buf,size_t count,loff_t * ppos)57 static ssize_t audmux_read_file(struct file *file, char __user *user_buf,
58 				size_t count, loff_t *ppos)
59 {
60 	ssize_t ret;
61 	char *buf;
62 	uintptr_t port = (uintptr_t)file->private_data;
63 	u32 pdcr, ptcr;
64 
65 	if (audmux_clk) {
66 		ret = clk_prepare_enable(audmux_clk);
67 		if (ret)
68 			return ret;
69 	}
70 
71 	ptcr = readl(audmux_base + IMX_AUDMUX_V2_PTCR(port));
72 	pdcr = readl(audmux_base + IMX_AUDMUX_V2_PDCR(port));
73 
74 	if (audmux_clk)
75 		clk_disable_unprepare(audmux_clk);
76 
77 	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
78 	if (!buf)
79 		return -ENOMEM;
80 
81 	ret = scnprintf(buf, PAGE_SIZE, "PDCR: %08x\nPTCR: %08x\n",
82 		       pdcr, ptcr);
83 
84 	if (ptcr & IMX_AUDMUX_V2_PTCR_TFSDIR)
85 		ret += scnprintf(buf + ret, PAGE_SIZE - ret,
86 				"TxFS output from %s, ",
87 				audmux_port_string((ptcr >> 27) & 0x7));
88 	else
89 		ret += scnprintf(buf + ret, PAGE_SIZE - ret,
90 				"TxFS input, ");
91 
92 	if (ptcr & IMX_AUDMUX_V2_PTCR_TCLKDIR)
93 		ret += scnprintf(buf + ret, PAGE_SIZE - ret,
94 				"TxClk output from %s",
95 				audmux_port_string((ptcr >> 22) & 0x7));
96 	else
97 		ret += scnprintf(buf + ret, PAGE_SIZE - ret,
98 				"TxClk input");
99 
100 	ret += scnprintf(buf + ret, PAGE_SIZE - ret, "\n");
101 
102 	if (ptcr & IMX_AUDMUX_V2_PTCR_SYN) {
103 		ret += scnprintf(buf + ret, PAGE_SIZE - ret,
104 				"Port is symmetric");
105 	} else {
106 		if (ptcr & IMX_AUDMUX_V2_PTCR_RFSDIR)
107 			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
108 					"RxFS output from %s, ",
109 					audmux_port_string((ptcr >> 17) & 0x7));
110 		else
111 			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
112 					"RxFS input, ");
113 
114 		if (ptcr & IMX_AUDMUX_V2_PTCR_RCLKDIR)
115 			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
116 					"RxClk output from %s",
117 					audmux_port_string((ptcr >> 12) & 0x7));
118 		else
119 			ret += scnprintf(buf + ret, PAGE_SIZE - ret,
120 					"RxClk input");
121 	}
122 
123 	ret += scnprintf(buf + ret, PAGE_SIZE - ret,
124 			"\nData received from %s\n",
125 			audmux_port_string((pdcr >> 13) & 0x7));
126 
127 	ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
128 
129 	kfree(buf);
130 
131 	return ret;
132 }
133 
134 static const struct file_operations audmux_debugfs_fops = {
135 	.open = simple_open,
136 	.read = audmux_read_file,
137 	.llseek = default_llseek,
138 };
139 
audmux_debugfs_init(void)140 static void audmux_debugfs_init(void)
141 {
142 	uintptr_t i;
143 	char buf[20];
144 
145 	audmux_debugfs_root = debugfs_create_dir("audmux", NULL);
146 
147 	for (i = 0; i < MX31_AUDMUX_PORT7_SSI_PINS_7 + 1; i++) {
148 		snprintf(buf, sizeof(buf), "ssi%lu", i);
149 		debugfs_create_file(buf, 0444, audmux_debugfs_root,
150 				    (void *)i, &audmux_debugfs_fops);
151 	}
152 }
153 
audmux_debugfs_remove(void)154 static void audmux_debugfs_remove(void)
155 {
156 	debugfs_remove_recursive(audmux_debugfs_root);
157 }
158 #else
audmux_debugfs_init(void)159 static inline void audmux_debugfs_init(void)
160 {
161 }
162 
audmux_debugfs_remove(void)163 static inline void audmux_debugfs_remove(void)
164 {
165 }
166 #endif
167 
168 static enum imx_audmux_type {
169 	IMX21_AUDMUX,
170 	IMX31_AUDMUX,
171 } audmux_type;
172 
173 static const struct platform_device_id imx_audmux_ids[] = {
174 	{
175 		.name = "imx21-audmux",
176 		.driver_data = IMX21_AUDMUX,
177 	}, {
178 		.name = "imx31-audmux",
179 		.driver_data = IMX31_AUDMUX,
180 	}, {
181 		/* sentinel */
182 	}
183 };
184 MODULE_DEVICE_TABLE(platform, imx_audmux_ids);
185 
186 static const struct of_device_id imx_audmux_dt_ids[] = {
187 	{ .compatible = "fsl,imx21-audmux", .data = &imx_audmux_ids[0], },
188 	{ .compatible = "fsl,imx31-audmux", .data = &imx_audmux_ids[1], },
189 	{ /* sentinel */ }
190 };
191 MODULE_DEVICE_TABLE(of, imx_audmux_dt_ids);
192 
193 static const uint8_t port_mapping[] = {
194 	0x0, 0x4, 0x8, 0x10, 0x14, 0x1c,
195 };
196 
imx_audmux_v1_configure_port(unsigned int port,unsigned int pcr)197 int imx_audmux_v1_configure_port(unsigned int port, unsigned int pcr)
198 {
199 	if (audmux_type != IMX21_AUDMUX)
200 		return -EINVAL;
201 
202 	if (!audmux_base)
203 		return -ENOSYS;
204 
205 	if (port >= ARRAY_SIZE(port_mapping))
206 		return -EINVAL;
207 
208 	writel(pcr, audmux_base + port_mapping[port]);
209 
210 	return 0;
211 }
212 EXPORT_SYMBOL_GPL(imx_audmux_v1_configure_port);
213 
imx_audmux_v2_configure_port(unsigned int port,unsigned int ptcr,unsigned int pdcr)214 int imx_audmux_v2_configure_port(unsigned int port, unsigned int ptcr,
215 		unsigned int pdcr)
216 {
217 	int ret;
218 
219 	if (audmux_type != IMX31_AUDMUX)
220 		return -EINVAL;
221 
222 	if (!audmux_base)
223 		return -ENOSYS;
224 
225 	if (audmux_clk) {
226 		ret = clk_prepare_enable(audmux_clk);
227 		if (ret)
228 			return ret;
229 	}
230 
231 	writel(ptcr, audmux_base + IMX_AUDMUX_V2_PTCR(port));
232 	writel(pdcr, audmux_base + IMX_AUDMUX_V2_PDCR(port));
233 
234 	if (audmux_clk)
235 		clk_disable_unprepare(audmux_clk);
236 
237 	return 0;
238 }
239 EXPORT_SYMBOL_GPL(imx_audmux_v2_configure_port);
240 
imx_audmux_parse_dt_defaults(struct platform_device * pdev,struct device_node * of_node)241 static int imx_audmux_parse_dt_defaults(struct platform_device *pdev,
242 		struct device_node *of_node)
243 {
244 	struct device_node *child;
245 
246 	for_each_available_child_of_node(of_node, child) {
247 		unsigned int port;
248 		unsigned int ptcr = 0;
249 		unsigned int pdcr = 0;
250 		unsigned int pcr = 0;
251 		unsigned int val;
252 		int ret;
253 		int i = 0;
254 
255 		ret = of_property_read_u32(child, "fsl,audmux-port", &port);
256 		if (ret) {
257 			dev_warn(&pdev->dev, "Failed to get fsl,audmux-port of child node \"%pOF\"\n",
258 					child);
259 			continue;
260 		}
261 		if (!of_property_read_bool(child, "fsl,port-config")) {
262 			dev_warn(&pdev->dev, "child node \"%pOF\" does not have property fsl,port-config\n",
263 					child);
264 			continue;
265 		}
266 
267 		for (i = 0; (ret = of_property_read_u32_index(child,
268 					"fsl,port-config", i, &val)) == 0;
269 				++i) {
270 			if (audmux_type == IMX31_AUDMUX) {
271 				if (i % 2)
272 					pdcr |= val;
273 				else
274 					ptcr |= val;
275 			} else {
276 				pcr |= val;
277 			}
278 		}
279 
280 		if (ret != -EOVERFLOW) {
281 			dev_err(&pdev->dev, "Failed to read u32 at index %d of child %pOF\n",
282 					i, child);
283 			continue;
284 		}
285 
286 		if (audmux_type == IMX31_AUDMUX) {
287 			if (i % 2) {
288 				dev_err(&pdev->dev, "One pdcr value is missing in child node %pOF\n",
289 						child);
290 				continue;
291 			}
292 			imx_audmux_v2_configure_port(port, ptcr, pdcr);
293 		} else {
294 			imx_audmux_v1_configure_port(port, pcr);
295 		}
296 	}
297 
298 	return 0;
299 }
300 
imx_audmux_probe(struct platform_device * pdev)301 static int imx_audmux_probe(struct platform_device *pdev)
302 {
303 	const struct of_device_id *of_id =
304 			of_match_device(imx_audmux_dt_ids, &pdev->dev);
305 
306 	audmux_base = devm_platform_ioremap_resource(pdev, 0);
307 	if (IS_ERR(audmux_base))
308 		return PTR_ERR(audmux_base);
309 
310 	audmux_clk = devm_clk_get(&pdev->dev, "audmux");
311 	if (IS_ERR(audmux_clk)) {
312 		dev_dbg(&pdev->dev, "cannot get clock: %ld\n",
313 				PTR_ERR(audmux_clk));
314 		audmux_clk = NULL;
315 	}
316 
317 	if (of_id)
318 		pdev->id_entry = of_id->data;
319 	audmux_type = pdev->id_entry->driver_data;
320 
321 	switch (audmux_type) {
322 	case IMX31_AUDMUX:
323 		audmux_debugfs_init();
324 		reg_max = 14;
325 		break;
326 	case IMX21_AUDMUX:
327 		reg_max = 6;
328 		break;
329 	default:
330 		dev_err(&pdev->dev, "unsupported version!\n");
331 		return -EINVAL;
332 	}
333 
334 	regcache = devm_kzalloc(&pdev->dev, sizeof(u32) * reg_max, GFP_KERNEL);
335 	if (!regcache)
336 		return -ENOMEM;
337 
338 	if (of_id)
339 		imx_audmux_parse_dt_defaults(pdev, pdev->dev.of_node);
340 
341 	return 0;
342 }
343 
imx_audmux_remove(struct platform_device * pdev)344 static int imx_audmux_remove(struct platform_device *pdev)
345 {
346 	if (audmux_type == IMX31_AUDMUX)
347 		audmux_debugfs_remove();
348 
349 	return 0;
350 }
351 
352 #ifdef CONFIG_PM_SLEEP
imx_audmux_suspend(struct device * dev)353 static int imx_audmux_suspend(struct device *dev)
354 {
355 	int i;
356 
357 	clk_prepare_enable(audmux_clk);
358 
359 	for (i = 0; i < reg_max; i++)
360 		regcache[i] = readl(audmux_base + i * 4);
361 
362 	clk_disable_unprepare(audmux_clk);
363 
364 	return 0;
365 }
366 
imx_audmux_resume(struct device * dev)367 static int imx_audmux_resume(struct device *dev)
368 {
369 	int i;
370 
371 	clk_prepare_enable(audmux_clk);
372 
373 	for (i = 0; i < reg_max; i++)
374 		writel(regcache[i], audmux_base + i * 4);
375 
376 	clk_disable_unprepare(audmux_clk);
377 
378 	return 0;
379 }
380 #endif /* CONFIG_PM_SLEEP */
381 
382 static const struct dev_pm_ops imx_audmux_pm = {
383 	SET_SYSTEM_SLEEP_PM_OPS(imx_audmux_suspend, imx_audmux_resume)
384 };
385 
386 static struct platform_driver imx_audmux_driver = {
387 	.probe		= imx_audmux_probe,
388 	.remove		= imx_audmux_remove,
389 	.id_table	= imx_audmux_ids,
390 	.driver	= {
391 		.name	= DRIVER_NAME,
392 		.pm = &imx_audmux_pm,
393 		.of_match_table = imx_audmux_dt_ids,
394 	}
395 };
396 
imx_audmux_init(void)397 static int __init imx_audmux_init(void)
398 {
399 	return platform_driver_register(&imx_audmux_driver);
400 }
401 subsys_initcall(imx_audmux_init);
402 
imx_audmux_exit(void)403 static void __exit imx_audmux_exit(void)
404 {
405 	platform_driver_unregister(&imx_audmux_driver);
406 }
407 module_exit(imx_audmux_exit);
408 
409 MODULE_DESCRIPTION("Freescale i.MX AUDMUX driver");
410 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
411 MODULE_LICENSE("GPL v2");
412 MODULE_ALIAS("platform:" DRIVER_NAME);
413