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