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 */
28int 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 */
48int 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 */
66static 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 */
96struct 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 */
121void ingenic_ecc_release(struct ingenic_ecc *ecc)
122{
123	clk_disable_unprepare(ecc->clk);
124	put_device(ecc->dev);
125}
126
127int 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}
159EXPORT_SYMBOL(ingenic_ecc_probe);
160