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