xref: /openbmc/linux/drivers/misc/xilinx_sdfec.c (revision b830f94f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Xilinx SDFEC
4  *
5  * Copyright (C) 2019 Xilinx, Inc.
6  *
7  * Description:
8  * This driver is developed for SDFEC16 (Soft Decision FEC 16nm)
9  * IP. It exposes a char device which supports file operations
10  * like  open(), close() and ioctl().
11  */
12 
13 #include <linux/miscdevice.h>
14 #include <linux/io.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/of_platform.h>
19 #include <linux/poll.h>
20 #include <linux/slab.h>
21 #include <linux/clk.h>
22 
23 #define DEV_NAME_LEN 12
24 
25 static struct idr dev_idr;
26 static struct mutex dev_idr_lock;
27 
28 /**
29  * struct xsdfec_clks - For managing SD-FEC clocks
30  * @core_clk: Main processing clock for core
31  * @axi_clk: AXI4-Lite memory-mapped clock
32  * @din_words_clk: DIN Words AXI4-Stream Slave clock
33  * @din_clk: DIN AXI4-Stream Slave clock
34  * @dout_clk: DOUT Words AXI4-Stream Slave clock
35  * @dout_words_clk: DOUT AXI4-Stream Slave clock
36  * @ctrl_clk: Control AXI4-Stream Slave clock
37  * @status_clk: Status AXI4-Stream Slave clock
38  */
39 struct xsdfec_clks {
40 	struct clk *core_clk;
41 	struct clk *axi_clk;
42 	struct clk *din_words_clk;
43 	struct clk *din_clk;
44 	struct clk *dout_clk;
45 	struct clk *dout_words_clk;
46 	struct clk *ctrl_clk;
47 	struct clk *status_clk;
48 };
49 
50 /**
51  * struct xsdfec_dev - Driver data for SDFEC
52  * @regs: device physical base address
53  * @dev: pointer to device struct
54  * @miscdev: Misc device handle
55  * @error_data_lock: Error counter and states spinlock
56  * @clks: Clocks managed by the SDFEC driver
57  * @dev_name: Device name
58  * @dev_id: Device ID
59  *
60  * This structure contains necessary state for SDFEC driver to operate
61  */
62 struct xsdfec_dev {
63 	void __iomem *regs;
64 	struct device *dev;
65 	struct miscdevice miscdev;
66 	/* Spinlock to protect state_updated and stats_updated */
67 	spinlock_t error_data_lock;
68 	struct xsdfec_clks clks;
69 	char dev_name[DEV_NAME_LEN];
70 	int dev_id;
71 };
72 
73 static const struct file_operations xsdfec_fops = {
74 	.owner = THIS_MODULE,
75 };
76 
77 static int xsdfec_clk_init(struct platform_device *pdev,
78 			   struct xsdfec_clks *clks)
79 {
80 	int err;
81 
82 	clks->core_clk = devm_clk_get(&pdev->dev, "core_clk");
83 	if (IS_ERR(clks->core_clk)) {
84 		dev_err(&pdev->dev, "failed to get core_clk");
85 		return PTR_ERR(clks->core_clk);
86 	}
87 
88 	clks->axi_clk = devm_clk_get(&pdev->dev, "s_axi_aclk");
89 	if (IS_ERR(clks->axi_clk)) {
90 		dev_err(&pdev->dev, "failed to get axi_clk");
91 		return PTR_ERR(clks->axi_clk);
92 	}
93 
94 	clks->din_words_clk = devm_clk_get(&pdev->dev, "s_axis_din_words_aclk");
95 	if (IS_ERR(clks->din_words_clk)) {
96 		if (PTR_ERR(clks->din_words_clk) != -ENOENT) {
97 			err = PTR_ERR(clks->din_words_clk);
98 			return err;
99 		}
100 		clks->din_words_clk = NULL;
101 	}
102 
103 	clks->din_clk = devm_clk_get(&pdev->dev, "s_axis_din_aclk");
104 	if (IS_ERR(clks->din_clk)) {
105 		if (PTR_ERR(clks->din_clk) != -ENOENT) {
106 			err = PTR_ERR(clks->din_clk);
107 			return err;
108 		}
109 		clks->din_clk = NULL;
110 	}
111 
112 	clks->dout_clk = devm_clk_get(&pdev->dev, "m_axis_dout_aclk");
113 	if (IS_ERR(clks->dout_clk)) {
114 		if (PTR_ERR(clks->dout_clk) != -ENOENT) {
115 			err = PTR_ERR(clks->dout_clk);
116 			return err;
117 		}
118 		clks->dout_clk = NULL;
119 	}
120 
121 	clks->dout_words_clk =
122 		devm_clk_get(&pdev->dev, "s_axis_dout_words_aclk");
123 	if (IS_ERR(clks->dout_words_clk)) {
124 		if (PTR_ERR(clks->dout_words_clk) != -ENOENT) {
125 			err = PTR_ERR(clks->dout_words_clk);
126 			return err;
127 		}
128 		clks->dout_words_clk = NULL;
129 	}
130 
131 	clks->ctrl_clk = devm_clk_get(&pdev->dev, "s_axis_ctrl_aclk");
132 	if (IS_ERR(clks->ctrl_clk)) {
133 		if (PTR_ERR(clks->ctrl_clk) != -ENOENT) {
134 			err = PTR_ERR(clks->ctrl_clk);
135 			return err;
136 		}
137 		clks->ctrl_clk = NULL;
138 	}
139 
140 	clks->status_clk = devm_clk_get(&pdev->dev, "m_axis_status_aclk");
141 	if (IS_ERR(clks->status_clk)) {
142 		if (PTR_ERR(clks->status_clk) != -ENOENT) {
143 			err = PTR_ERR(clks->status_clk);
144 			return err;
145 		}
146 		clks->status_clk = NULL;
147 	}
148 
149 	err = clk_prepare_enable(clks->core_clk);
150 	if (err) {
151 		dev_err(&pdev->dev, "failed to enable core_clk (%d)", err);
152 		return err;
153 	}
154 
155 	err = clk_prepare_enable(clks->axi_clk);
156 	if (err) {
157 		dev_err(&pdev->dev, "failed to enable axi_clk (%d)", err);
158 		goto err_disable_core_clk;
159 	}
160 
161 	err = clk_prepare_enable(clks->din_clk);
162 	if (err) {
163 		dev_err(&pdev->dev, "failed to enable din_clk (%d)", err);
164 		goto err_disable_axi_clk;
165 	}
166 
167 	err = clk_prepare_enable(clks->din_words_clk);
168 	if (err) {
169 		dev_err(&pdev->dev, "failed to enable din_words_clk (%d)", err);
170 		goto err_disable_din_clk;
171 	}
172 
173 	err = clk_prepare_enable(clks->dout_clk);
174 	if (err) {
175 		dev_err(&pdev->dev, "failed to enable dout_clk (%d)", err);
176 		goto err_disable_din_words_clk;
177 	}
178 
179 	err = clk_prepare_enable(clks->dout_words_clk);
180 	if (err) {
181 		dev_err(&pdev->dev, "failed to enable dout_words_clk (%d)",
182 			err);
183 		goto err_disable_dout_clk;
184 	}
185 
186 	err = clk_prepare_enable(clks->ctrl_clk);
187 	if (err) {
188 		dev_err(&pdev->dev, "failed to enable ctrl_clk (%d)", err);
189 		goto err_disable_dout_words_clk;
190 	}
191 
192 	err = clk_prepare_enable(clks->status_clk);
193 	if (err) {
194 		dev_err(&pdev->dev, "failed to enable status_clk (%d)\n", err);
195 		goto err_disable_ctrl_clk;
196 	}
197 
198 	return err;
199 
200 err_disable_ctrl_clk:
201 	clk_disable_unprepare(clks->ctrl_clk);
202 err_disable_dout_words_clk:
203 	clk_disable_unprepare(clks->dout_words_clk);
204 err_disable_dout_clk:
205 	clk_disable_unprepare(clks->dout_clk);
206 err_disable_din_words_clk:
207 	clk_disable_unprepare(clks->din_words_clk);
208 err_disable_din_clk:
209 	clk_disable_unprepare(clks->din_clk);
210 err_disable_axi_clk:
211 	clk_disable_unprepare(clks->axi_clk);
212 err_disable_core_clk:
213 	clk_disable_unprepare(clks->core_clk);
214 
215 	return err;
216 }
217 
218 static void xsdfec_disable_all_clks(struct xsdfec_clks *clks)
219 {
220 	clk_disable_unprepare(clks->status_clk);
221 	clk_disable_unprepare(clks->ctrl_clk);
222 	clk_disable_unprepare(clks->dout_words_clk);
223 	clk_disable_unprepare(clks->dout_clk);
224 	clk_disable_unprepare(clks->din_words_clk);
225 	clk_disable_unprepare(clks->din_clk);
226 	clk_disable_unprepare(clks->core_clk);
227 	clk_disable_unprepare(clks->axi_clk);
228 }
229 
230 static void xsdfec_idr_remove(struct xsdfec_dev *xsdfec)
231 {
232 	mutex_lock(&dev_idr_lock);
233 	idr_remove(&dev_idr, xsdfec->dev_id);
234 	mutex_unlock(&dev_idr_lock);
235 }
236 
237 static int xsdfec_probe(struct platform_device *pdev)
238 {
239 	struct xsdfec_dev *xsdfec;
240 	struct device *dev;
241 	struct resource *res;
242 	int err;
243 
244 	xsdfec = devm_kzalloc(&pdev->dev, sizeof(*xsdfec), GFP_KERNEL);
245 	if (!xsdfec)
246 		return -ENOMEM;
247 
248 	xsdfec->dev = &pdev->dev;
249 	spin_lock_init(&xsdfec->error_data_lock);
250 
251 	err = xsdfec_clk_init(pdev, &xsdfec->clks);
252 	if (err)
253 		return err;
254 
255 	dev = xsdfec->dev;
256 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
257 	xsdfec->regs = devm_ioremap_resource(dev, res);
258 	if (IS_ERR(xsdfec->regs)) {
259 		err = PTR_ERR(xsdfec->regs);
260 		goto err_xsdfec_dev;
261 	}
262 
263 	/* Save driver private data */
264 	platform_set_drvdata(pdev, xsdfec);
265 
266 	mutex_lock(&dev_idr_lock);
267 	err = idr_alloc(&dev_idr, xsdfec->dev_name, 0, 0, GFP_KERNEL);
268 	mutex_unlock(&dev_idr_lock);
269 	if (err < 0)
270 		goto err_xsdfec_dev;
271 	xsdfec->dev_id = err;
272 
273 	snprintf(xsdfec->dev_name, DEV_NAME_LEN, "xsdfec%d", xsdfec->dev_id);
274 	xsdfec->miscdev.minor = MISC_DYNAMIC_MINOR;
275 	xsdfec->miscdev.name = xsdfec->dev_name;
276 	xsdfec->miscdev.fops = &xsdfec_fops;
277 	xsdfec->miscdev.parent = dev;
278 	err = misc_register(&xsdfec->miscdev);
279 	if (err) {
280 		dev_err(dev, "error:%d. Unable to register device", err);
281 		goto err_xsdfec_idr;
282 	}
283 	return 0;
284 
285 err_xsdfec_idr:
286 	xsdfec_idr_remove(xsdfec);
287 err_xsdfec_dev:
288 	xsdfec_disable_all_clks(&xsdfec->clks);
289 	return err;
290 }
291 
292 static int xsdfec_remove(struct platform_device *pdev)
293 {
294 	struct xsdfec_dev *xsdfec;
295 
296 	xsdfec = platform_get_drvdata(pdev);
297 	misc_deregister(&xsdfec->miscdev);
298 	xsdfec_idr_remove(xsdfec);
299 	xsdfec_disable_all_clks(&xsdfec->clks);
300 	return 0;
301 }
302 
303 static const struct of_device_id xsdfec_of_match[] = {
304 	{
305 		.compatible = "xlnx,sd-fec-1.1",
306 	},
307 	{ /* end of table */ }
308 };
309 MODULE_DEVICE_TABLE(of, xsdfec_of_match);
310 
311 static struct platform_driver xsdfec_driver = {
312 	.driver = {
313 		.name = "xilinx-sdfec",
314 		.of_match_table = xsdfec_of_match,
315 	},
316 	.probe = xsdfec_probe,
317 	.remove =  xsdfec_remove,
318 };
319 
320 static int __init xsdfec_init(void)
321 {
322 	int err;
323 
324 	mutex_init(&dev_idr_lock);
325 	idr_init(&dev_idr);
326 	err = platform_driver_register(&xsdfec_driver);
327 	if (err < 0) {
328 		pr_err("%s Unabled to register SDFEC driver", __func__);
329 		return err;
330 	}
331 	return 0;
332 }
333 
334 static void __exit xsdfec_exit(void)
335 {
336 	platform_driver_unregister(&xsdfec_driver);
337 	idr_destroy(&dev_idr);
338 }
339 
340 module_init(xsdfec_init);
341 module_exit(xsdfec_exit);
342 
343 MODULE_AUTHOR("Xilinx, Inc");
344 MODULE_DESCRIPTION("Xilinx SD-FEC16 Driver");
345 MODULE_LICENSE("GPL");
346