1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * JZ47xx ECC common code
4  *
5  * Copyright (c) 2015 Imagination Technologies
6  * Author: Alex Smith <alex.smith@imgtec.com>
7  */
8 
9 #include <linux/clk.h>
10 #include <linux/init.h>
11 #include <linux/module.h>
12 #include <linux/of.h>
13 #include <linux/of_platform.h>
14 #include <linux/platform_device.h>
15 
16 #include "ingenic_ecc.h"
17 
18 /**
19  * ingenic_ecc_calculate() - calculate ECC for a data buffer
20  * @ecc: ECC device.
21  * @params: ECC parameters.
22  * @buf: input buffer with raw data.
23  * @ecc_code: output buffer with ECC.
24  *
25  * Return: 0 on success, -ETIMEDOUT if timed out while waiting for ECC
26  * controller.
27  */
28 int ingenic_ecc_calculate(struct ingenic_ecc *ecc,
29 			  struct ingenic_ecc_params *params,
30 			  const u8 *buf, u8 *ecc_code)
31 {
32 	return ecc->ops->calculate(ecc, params, buf, ecc_code);
33 }
34 
35 /**
36  * ingenic_ecc_correct() - detect and correct bit errors
37  * @ecc: ECC device.
38  * @params: ECC parameters.
39  * @buf: raw data read from the chip.
40  * @ecc_code: ECC read from the chip.
41  *
42  * Given the raw data and the ECC read from the NAND device, detects and
43  * corrects errors in the data.
44  *
45  * Return: the number of bit errors corrected, -EBADMSG if there are too many
46  * errors to correct or -ETIMEDOUT if we timed out waiting for the controller.
47  */
48 int ingenic_ecc_correct(struct ingenic_ecc *ecc,
49 			struct ingenic_ecc_params *params,
50 			u8 *buf, u8 *ecc_code)
51 {
52 	return ecc->ops->correct(ecc, params, buf, ecc_code);
53 }
54 
55 /**
56  * ingenic_ecc_get() - get the ECC controller device
57  * @np: ECC device tree node.
58  *
59  * Gets the ECC controller device from the specified device tree node. The
60  * device must be released with ingenic_ecc_release() when it is no longer being
61  * used.
62  *
63  * Return: a pointer to ingenic_ecc, errors are encoded into the pointer.
64  * PTR_ERR(-EPROBE_DEFER) if the device hasn't been initialised yet.
65  */
66 static struct ingenic_ecc *ingenic_ecc_get(struct device_node *np)
67 {
68 	struct platform_device *pdev;
69 	struct ingenic_ecc *ecc;
70 
71 	pdev = of_find_device_by_node(np);
72 	if (!pdev)
73 		return ERR_PTR(-EPROBE_DEFER);
74 
75 	if (!platform_get_drvdata(pdev)) {
76 		put_device(&pdev->dev);
77 		return ERR_PTR(-EPROBE_DEFER);
78 	}
79 
80 	ecc = platform_get_drvdata(pdev);
81 	clk_prepare_enable(ecc->clk);
82 
83 	return ecc;
84 }
85 
86 /**
87  * of_ingenic_ecc_get() - get the ECC controller from a DT node
88  * @of_node: the node that contains an ecc-engine property.
89  *
90  * Get the ecc-engine property from the given device tree
91  * node and pass it to ingenic_ecc_get to do the work.
92  *
93  * Return: a pointer to ingenic_ecc, errors are encoded into the pointer.
94  * PTR_ERR(-EPROBE_DEFER) if the device hasn't been initialised yet.
95  */
96 struct ingenic_ecc *of_ingenic_ecc_get(struct device_node *of_node)
97 {
98 	struct ingenic_ecc *ecc = NULL;
99 	struct device_node *np;
100 
101 	np = of_parse_phandle(of_node, "ecc-engine", 0);
102 
103 	/*
104 	 * If the ecc-engine property is not found, check for the deprecated
105 	 * ingenic,bch-controller property
106 	 */
107 	if (!np)
108 		np = of_parse_phandle(of_node, "ingenic,bch-controller", 0);
109 
110 	if (np) {
111 		ecc = ingenic_ecc_get(np);
112 		of_node_put(np);
113 	}
114 	return ecc;
115 }
116 
117 /**
118  * ingenic_ecc_release() - release the ECC controller device
119  * @ecc: ECC device.
120  */
121 void ingenic_ecc_release(struct ingenic_ecc *ecc)
122 {
123 	clk_disable_unprepare(ecc->clk);
124 	put_device(ecc->dev);
125 }
126 
127 int ingenic_ecc_probe(struct platform_device *pdev)
128 {
129 	struct device *dev = &pdev->dev;
130 	struct ingenic_ecc *ecc;
131 
132 	ecc = devm_kzalloc(dev, sizeof(*ecc), GFP_KERNEL);
133 	if (!ecc)
134 		return -ENOMEM;
135 
136 	ecc->ops = device_get_match_data(dev);
137 	if (!ecc->ops)
138 		return -EINVAL;
139 
140 	ecc->base = devm_platform_ioremap_resource(pdev, 0);
141 	if (IS_ERR(ecc->base))
142 		return PTR_ERR(ecc->base);
143 
144 	ecc->ops->disable(ecc);
145 
146 	ecc->clk = devm_clk_get(dev, NULL);
147 	if (IS_ERR(ecc->clk)) {
148 		dev_err(dev, "failed to get clock: %ld\n", PTR_ERR(ecc->clk));
149 		return PTR_ERR(ecc->clk);
150 	}
151 
152 	mutex_init(&ecc->lock);
153 
154 	ecc->dev = dev;
155 	platform_set_drvdata(pdev, ecc);
156 
157 	return 0;
158 }
159 EXPORT_SYMBOL(ingenic_ecc_probe);
160