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, https://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 of_device_id imx_audmux_dt_ids[] = {
174 	{ .compatible = "fsl,imx21-audmux", .data = (void *)IMX21_AUDMUX, },
175 	{ .compatible = "fsl,imx31-audmux", .data = (void *)IMX31_AUDMUX, },
176 	{ /* sentinel */ }
177 };
178 MODULE_DEVICE_TABLE(of, imx_audmux_dt_ids);
179 
180 static const uint8_t port_mapping[] = {
181 	0x0, 0x4, 0x8, 0x10, 0x14, 0x1c,
182 };
183 
imx_audmux_v1_configure_port(unsigned int port,unsigned int pcr)184 int imx_audmux_v1_configure_port(unsigned int port, unsigned int pcr)
185 {
186 	if (audmux_type != IMX21_AUDMUX)
187 		return -EINVAL;
188 
189 	if (!audmux_base)
190 		return -ENOSYS;
191 
192 	if (port >= ARRAY_SIZE(port_mapping))
193 		return -EINVAL;
194 
195 	writel(pcr, audmux_base + port_mapping[port]);
196 
197 	return 0;
198 }
199 EXPORT_SYMBOL_GPL(imx_audmux_v1_configure_port);
200 
imx_audmux_v2_configure_port(unsigned int port,unsigned int ptcr,unsigned int pdcr)201 int imx_audmux_v2_configure_port(unsigned int port, unsigned int ptcr,
202 		unsigned int pdcr)
203 {
204 	int ret;
205 
206 	if (audmux_type != IMX31_AUDMUX)
207 		return -EINVAL;
208 
209 	if (!audmux_base)
210 		return -ENOSYS;
211 
212 	if (audmux_clk) {
213 		ret = clk_prepare_enable(audmux_clk);
214 		if (ret)
215 			return ret;
216 	}
217 
218 	writel(ptcr, audmux_base + IMX_AUDMUX_V2_PTCR(port));
219 	writel(pdcr, audmux_base + IMX_AUDMUX_V2_PDCR(port));
220 
221 	if (audmux_clk)
222 		clk_disable_unprepare(audmux_clk);
223 
224 	return 0;
225 }
226 EXPORT_SYMBOL_GPL(imx_audmux_v2_configure_port);
227 
imx_audmux_parse_dt_defaults(struct platform_device * pdev,struct device_node * of_node)228 static int imx_audmux_parse_dt_defaults(struct platform_device *pdev,
229 		struct device_node *of_node)
230 {
231 	struct device_node *child;
232 
233 	for_each_available_child_of_node(of_node, child) {
234 		unsigned int port;
235 		unsigned int ptcr = 0;
236 		unsigned int pdcr = 0;
237 		unsigned int pcr = 0;
238 		unsigned int val;
239 		int ret;
240 		int i = 0;
241 
242 		ret = of_property_read_u32(child, "fsl,audmux-port", &port);
243 		if (ret) {
244 			dev_warn(&pdev->dev, "Failed to get fsl,audmux-port of child node \"%pOF\"\n",
245 					child);
246 			continue;
247 		}
248 		if (!of_property_read_bool(child, "fsl,port-config")) {
249 			dev_warn(&pdev->dev, "child node \"%pOF\" does not have property fsl,port-config\n",
250 					child);
251 			continue;
252 		}
253 
254 		for (i = 0; (ret = of_property_read_u32_index(child,
255 					"fsl,port-config", i, &val)) == 0;
256 				++i) {
257 			if (audmux_type == IMX31_AUDMUX) {
258 				if (i % 2)
259 					pdcr |= val;
260 				else
261 					ptcr |= val;
262 			} else {
263 				pcr |= val;
264 			}
265 		}
266 
267 		if (ret != -EOVERFLOW) {
268 			dev_err(&pdev->dev, "Failed to read u32 at index %d of child %pOF\n",
269 					i, child);
270 			continue;
271 		}
272 
273 		if (audmux_type == IMX31_AUDMUX) {
274 			if (i % 2) {
275 				dev_err(&pdev->dev, "One pdcr value is missing in child node %pOF\n",
276 						child);
277 				continue;
278 			}
279 			imx_audmux_v2_configure_port(port, ptcr, pdcr);
280 		} else {
281 			imx_audmux_v1_configure_port(port, pcr);
282 		}
283 	}
284 
285 	return 0;
286 }
287 
imx_audmux_probe(struct platform_device * pdev)288 static int imx_audmux_probe(struct platform_device *pdev)
289 {
290 	audmux_base = devm_platform_ioremap_resource(pdev, 0);
291 	if (IS_ERR(audmux_base))
292 		return PTR_ERR(audmux_base);
293 
294 	audmux_clk = devm_clk_get(&pdev->dev, "audmux");
295 	if (IS_ERR(audmux_clk)) {
296 		dev_dbg(&pdev->dev, "cannot get clock: %ld\n",
297 				PTR_ERR(audmux_clk));
298 		audmux_clk = NULL;
299 	}
300 
301 	audmux_type = (uintptr_t)of_device_get_match_data(&pdev->dev);
302 
303 	switch (audmux_type) {
304 	case IMX31_AUDMUX:
305 		audmux_debugfs_init();
306 		reg_max = 14;
307 		break;
308 	case IMX21_AUDMUX:
309 		reg_max = 6;
310 		break;
311 	default:
312 		dev_err(&pdev->dev, "unsupported version!\n");
313 		return -EINVAL;
314 	}
315 
316 	regcache = devm_kzalloc(&pdev->dev, sizeof(u32) * reg_max, GFP_KERNEL);
317 	if (!regcache)
318 		return -ENOMEM;
319 
320 	imx_audmux_parse_dt_defaults(pdev, pdev->dev.of_node);
321 
322 	return 0;
323 }
324 
imx_audmux_remove(struct platform_device * pdev)325 static int imx_audmux_remove(struct platform_device *pdev)
326 {
327 	if (audmux_type == IMX31_AUDMUX)
328 		audmux_debugfs_remove();
329 
330 	return 0;
331 }
332 
333 #ifdef CONFIG_PM_SLEEP
imx_audmux_suspend(struct device * dev)334 static int imx_audmux_suspend(struct device *dev)
335 {
336 	int i;
337 
338 	clk_prepare_enable(audmux_clk);
339 
340 	for (i = 0; i < reg_max; i++)
341 		regcache[i] = readl(audmux_base + i * 4);
342 
343 	clk_disable_unprepare(audmux_clk);
344 
345 	return 0;
346 }
347 
imx_audmux_resume(struct device * dev)348 static int imx_audmux_resume(struct device *dev)
349 {
350 	int i;
351 
352 	clk_prepare_enable(audmux_clk);
353 
354 	for (i = 0; i < reg_max; i++)
355 		writel(regcache[i], audmux_base + i * 4);
356 
357 	clk_disable_unprepare(audmux_clk);
358 
359 	return 0;
360 }
361 #endif /* CONFIG_PM_SLEEP */
362 
363 static const struct dev_pm_ops imx_audmux_pm = {
364 	SET_SYSTEM_SLEEP_PM_OPS(imx_audmux_suspend, imx_audmux_resume)
365 };
366 
367 static struct platform_driver imx_audmux_driver = {
368 	.probe		= imx_audmux_probe,
369 	.remove		= imx_audmux_remove,
370 	.driver	= {
371 		.name	= DRIVER_NAME,
372 		.pm = &imx_audmux_pm,
373 		.of_match_table = imx_audmux_dt_ids,
374 	}
375 };
376 
imx_audmux_init(void)377 static int __init imx_audmux_init(void)
378 {
379 	return platform_driver_register(&imx_audmux_driver);
380 }
381 subsys_initcall(imx_audmux_init);
382 
imx_audmux_exit(void)383 static void __exit imx_audmux_exit(void)
384 {
385 	platform_driver_unregister(&imx_audmux_driver);
386 }
387 module_exit(imx_audmux_exit);
388 
389 MODULE_DESCRIPTION("Freescale i.MX AUDMUX driver");
390 MODULE_AUTHOR("Sascha Hauer <s.hauer@pengutronix.de>");
391 MODULE_LICENSE("GPL v2");
392 MODULE_ALIAS("platform:" DRIVER_NAME);
393