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 */
ingenic_ecc_calculate(struct ingenic_ecc * ecc,struct ingenic_ecc_params * params,const u8 * buf,u8 * ecc_code)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 */
ingenic_ecc_correct(struct ingenic_ecc * ecc,struct ingenic_ecc_params * params,u8 * buf,u8 * ecc_code)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 */
ingenic_ecc_get(struct device_node * np)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 */
of_ingenic_ecc_get(struct device_node * of_node)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 */
ingenic_ecc_release(struct ingenic_ecc * ecc)121 void ingenic_ecc_release(struct ingenic_ecc *ecc)
122 {
123 clk_disable_unprepare(ecc->clk);
124 put_device(ecc->dev);
125 }
126
ingenic_ecc_probe(struct platform_device * pdev)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