1/*
2 * Arasan Secure Digital Host Controller Interface.
3 * Copyright (C) 2011 - 2012 Michal Simek <monstr@monstr.eu>
4 * Copyright (c) 2012 Wind River Systems, Inc.
5 * Copyright (C) 2013 Pengutronix e.K.
6 * Copyright (C) 2013 Xilinx Inc.
7 *
8 * Based on sdhci-of-esdhc.c
9 *
10 * Copyright (c) 2007 Freescale Semiconductor, Inc.
11 * Copyright (c) 2009 MontaVista Software, Inc.
12 *
13 * Authors: Xiaobo Xie <X.Xie@freescale.com>
14 *	    Anton Vorontsov <avorontsov@ru.mvista.com>
15 *
16 * This program is free software; you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation; either version 2 of the License, or (at
19 * your option) any later version.
20 */
21
22#include <linux/module.h>
23#include "sdhci-pltfm.h"
24
25#define SDHCI_ARASAN_CLK_CTRL_OFFSET	0x2c
26
27#define CLK_CTRL_TIMEOUT_SHIFT		16
28#define CLK_CTRL_TIMEOUT_MASK		(0xf << CLK_CTRL_TIMEOUT_SHIFT)
29#define CLK_CTRL_TIMEOUT_MIN_EXP	13
30
31/**
32 * struct sdhci_arasan_data
33 * @clk_ahb:	Pointer to the AHB clock
34 */
35struct sdhci_arasan_data {
36	struct clk	*clk_ahb;
37};
38
39static unsigned int sdhci_arasan_get_timeout_clock(struct sdhci_host *host)
40{
41	u32 div;
42	unsigned long freq;
43	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
44
45	div = readl(host->ioaddr + SDHCI_ARASAN_CLK_CTRL_OFFSET);
46	div = (div & CLK_CTRL_TIMEOUT_MASK) >> CLK_CTRL_TIMEOUT_SHIFT;
47
48	freq = clk_get_rate(pltfm_host->clk);
49	freq /= 1 << (CLK_CTRL_TIMEOUT_MIN_EXP + div);
50
51	return freq;
52}
53
54static struct sdhci_ops sdhci_arasan_ops = {
55	.set_clock = sdhci_set_clock,
56	.get_max_clock = sdhci_pltfm_clk_get_max_clock,
57	.get_timeout_clock = sdhci_arasan_get_timeout_clock,
58	.set_bus_width = sdhci_set_bus_width,
59	.reset = sdhci_reset,
60	.set_uhs_signaling = sdhci_set_uhs_signaling,
61};
62
63static struct sdhci_pltfm_data sdhci_arasan_pdata = {
64	.ops = &sdhci_arasan_ops,
65};
66
67#ifdef CONFIG_PM_SLEEP
68/**
69 * sdhci_arasan_suspend - Suspend method for the driver
70 * @dev:	Address of the device structure
71 * Returns 0 on success and error value on error
72 *
73 * Put the device in a low power state.
74 */
75static int sdhci_arasan_suspend(struct device *dev)
76{
77	struct platform_device *pdev = to_platform_device(dev);
78	struct sdhci_host *host = platform_get_drvdata(pdev);
79	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
80	struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
81	int ret;
82
83	ret = sdhci_suspend_host(host);
84	if (ret)
85		return ret;
86
87	clk_disable(pltfm_host->clk);
88	clk_disable(sdhci_arasan->clk_ahb);
89
90	return 0;
91}
92
93/**
94 * sdhci_arasan_resume - Resume method for the driver
95 * @dev:	Address of the device structure
96 * Returns 0 on success and error value on error
97 *
98 * Resume operation after suspend
99 */
100static int sdhci_arasan_resume(struct device *dev)
101{
102	struct platform_device *pdev = to_platform_device(dev);
103	struct sdhci_host *host = platform_get_drvdata(pdev);
104	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
105	struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
106	int ret;
107
108	ret = clk_enable(sdhci_arasan->clk_ahb);
109	if (ret) {
110		dev_err(dev, "Cannot enable AHB clock.\n");
111		return ret;
112	}
113
114	ret = clk_enable(pltfm_host->clk);
115	if (ret) {
116		dev_err(dev, "Cannot enable SD clock.\n");
117		clk_disable(sdhci_arasan->clk_ahb);
118		return ret;
119	}
120
121	return sdhci_resume_host(host);
122}
123#endif /* ! CONFIG_PM_SLEEP */
124
125static SIMPLE_DEV_PM_OPS(sdhci_arasan_dev_pm_ops, sdhci_arasan_suspend,
126			 sdhci_arasan_resume);
127
128static int sdhci_arasan_probe(struct platform_device *pdev)
129{
130	int ret;
131	struct clk *clk_xin;
132	struct sdhci_host *host;
133	struct sdhci_pltfm_host *pltfm_host;
134	struct sdhci_arasan_data *sdhci_arasan;
135
136	sdhci_arasan = devm_kzalloc(&pdev->dev, sizeof(*sdhci_arasan),
137			GFP_KERNEL);
138	if (!sdhci_arasan)
139		return -ENOMEM;
140
141	sdhci_arasan->clk_ahb = devm_clk_get(&pdev->dev, "clk_ahb");
142	if (IS_ERR(sdhci_arasan->clk_ahb)) {
143		dev_err(&pdev->dev, "clk_ahb clock not found.\n");
144		return PTR_ERR(sdhci_arasan->clk_ahb);
145	}
146
147	clk_xin = devm_clk_get(&pdev->dev, "clk_xin");
148	if (IS_ERR(clk_xin)) {
149		dev_err(&pdev->dev, "clk_xin clock not found.\n");
150		return PTR_ERR(clk_xin);
151	}
152
153	ret = clk_prepare_enable(sdhci_arasan->clk_ahb);
154	if (ret) {
155		dev_err(&pdev->dev, "Unable to enable AHB clock.\n");
156		return ret;
157	}
158
159	ret = clk_prepare_enable(clk_xin);
160	if (ret) {
161		dev_err(&pdev->dev, "Unable to enable SD clock.\n");
162		goto clk_dis_ahb;
163	}
164
165	host = sdhci_pltfm_init(pdev, &sdhci_arasan_pdata, 0);
166	if (IS_ERR(host)) {
167		ret = PTR_ERR(host);
168		dev_err(&pdev->dev, "platform init failed (%u)\n", ret);
169		goto clk_disable_all;
170	}
171
172	sdhci_get_of_property(pdev);
173	pltfm_host = sdhci_priv(host);
174	pltfm_host->priv = sdhci_arasan;
175	pltfm_host->clk = clk_xin;
176
177	ret = sdhci_add_host(host);
178	if (ret) {
179		dev_err(&pdev->dev, "platform register failed (%u)\n", ret);
180		goto err_pltfm_free;
181	}
182
183	return 0;
184
185err_pltfm_free:
186	sdhci_pltfm_free(pdev);
187clk_disable_all:
188	clk_disable_unprepare(clk_xin);
189clk_dis_ahb:
190	clk_disable_unprepare(sdhci_arasan->clk_ahb);
191
192	return ret;
193}
194
195static int sdhci_arasan_remove(struct platform_device *pdev)
196{
197	struct sdhci_host *host = platform_get_drvdata(pdev);
198	struct sdhci_pltfm_host *pltfm_host = sdhci_priv(host);
199	struct sdhci_arasan_data *sdhci_arasan = pltfm_host->priv;
200
201	clk_disable_unprepare(pltfm_host->clk);
202	clk_disable_unprepare(sdhci_arasan->clk_ahb);
203
204	return sdhci_pltfm_unregister(pdev);
205}
206
207static const struct of_device_id sdhci_arasan_of_match[] = {
208	{ .compatible = "arasan,sdhci-8.9a" },
209	{ }
210};
211MODULE_DEVICE_TABLE(of, sdhci_arasan_of_match);
212
213static struct platform_driver sdhci_arasan_driver = {
214	.driver = {
215		.name = "sdhci-arasan",
216		.of_match_table = sdhci_arasan_of_match,
217		.pm = &sdhci_arasan_dev_pm_ops,
218	},
219	.probe = sdhci_arasan_probe,
220	.remove = sdhci_arasan_remove,
221};
222
223module_platform_driver(sdhci_arasan_driver);
224
225MODULE_DESCRIPTION("Driver for the Arasan SDHCI Controller");
226MODULE_AUTHOR("Soeren Brinkmann <soren.brinkmann@xilinx.com>");
227MODULE_LICENSE("GPL");
228