1/*
  2 * Copyright (c) 2015-2016 MediaTek Inc.
  3 * Author: Yong Wu <yong.wu@mediatek.com>
  4 *
  5 * This program is free software; you can redistribute it and/or modify
  6 * it under the terms of the GNU General Public License version 2 as
  7 * published by the Free Software Foundation.
  8 *
  9 * This program is distributed in the hope that it will be useful,
 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 12 * GNU General Public License for more details.
 13 */
 14#include <linux/clk.h>
 15#include <linux/component.h>
 16#include <linux/device.h>
 17#include <linux/err.h>
 18#include <linux/io.h>
 19#include <linux/of.h>
 20#include <linux/of_platform.h>
 21#include <linux/platform_device.h>
 22#include <linux/pm_runtime.h>
 23#include <soc/mediatek/smi.h>
 24
 25#define SMI_LARB_MMU_EN		0xf00
 26
 27struct mtk_smi {
 28	struct device	*dev;
 29	struct clk	*clk_apb, *clk_smi;
 30};
 31
 32struct mtk_smi_larb { /* larb: local arbiter */
 33	struct mtk_smi  smi;
 34	void __iomem	*base;
 35	struct device	*smi_common_dev;
 36	u32		*mmu;
 37};
 38
 39static int mtk_smi_enable(const struct mtk_smi *smi)
 40{
 41	int ret;
 42
 43	ret = pm_runtime_get_sync(smi->dev);
 44	if (ret < 0)
 45		return ret;
 46
 47	ret = clk_prepare_enable(smi->clk_apb);
 48	if (ret)
 49		goto err_put_pm;
 50
 51	ret = clk_prepare_enable(smi->clk_smi);
 52	if (ret)
 53		goto err_disable_apb;
 54
 55	return 0;
 56
 57err_disable_apb:
 58	clk_disable_unprepare(smi->clk_apb);
 59err_put_pm:
 60	pm_runtime_put_sync(smi->dev);
 61	return ret;
 62}
 63
 64static void mtk_smi_disable(const struct mtk_smi *smi)
 65{
 66	clk_disable_unprepare(smi->clk_smi);
 67	clk_disable_unprepare(smi->clk_apb);
 68	pm_runtime_put_sync(smi->dev);
 69}
 70
 71int mtk_smi_larb_get(struct device *larbdev)
 72{
 73	struct mtk_smi_larb *larb = dev_get_drvdata(larbdev);
 74	struct mtk_smi *common = dev_get_drvdata(larb->smi_common_dev);
 75	int ret;
 76
 77	/* Enable the smi-common's power and clocks */
 78	ret = mtk_smi_enable(common);
 79	if (ret)
 80		return ret;
 81
 82	/* Enable the larb's power and clocks */
 83	ret = mtk_smi_enable(&larb->smi);
 84	if (ret) {
 85		mtk_smi_disable(common);
 86		return ret;
 87	}
 88
 89	/* Configure the iommu info for this larb */
 90	writel(*larb->mmu, larb->base + SMI_LARB_MMU_EN);
 91
 92	return 0;
 93}
 94
 95void mtk_smi_larb_put(struct device *larbdev)
 96{
 97	struct mtk_smi_larb *larb = dev_get_drvdata(larbdev);
 98	struct mtk_smi *common = dev_get_drvdata(larb->smi_common_dev);
 99
100	/*
101	 * Don't de-configure the iommu info for this larb since there may be
102	 * several modules in this larb.
103	 * The iommu info will be reset after power off.
104	 */
105
106	mtk_smi_disable(&larb->smi);
107	mtk_smi_disable(common);
108}
109
110static int
111mtk_smi_larb_bind(struct device *dev, struct device *master, void *data)
112{
113	struct mtk_smi_larb *larb = dev_get_drvdata(dev);
114	struct mtk_smi_iommu *smi_iommu = data;
115	unsigned int         i;
116
117	for (i = 0; i < smi_iommu->larb_nr; i++) {
118		if (dev == smi_iommu->larb_imu[i].dev) {
119			/* The 'mmu' may be updated in iommu-attach/detach. */
120			larb->mmu = &smi_iommu->larb_imu[i].mmu;
121			return 0;
122		}
123	}
124	return -ENODEV;
125}
126
127static void
128mtk_smi_larb_unbind(struct device *dev, struct device *master, void *data)
129{
130	/* Do nothing as the iommu is always enabled. */
131}
132
133static const struct component_ops mtk_smi_larb_component_ops = {
134	.bind = mtk_smi_larb_bind,
135	.unbind = mtk_smi_larb_unbind,
136};
137
138static int mtk_smi_larb_probe(struct platform_device *pdev)
139{
140	struct mtk_smi_larb *larb;
141	struct resource *res;
142	struct device *dev = &pdev->dev;
143	struct device_node *smi_node;
144	struct platform_device *smi_pdev;
145
146	if (!dev->pm_domain)
147		return -EPROBE_DEFER;
148
149	larb = devm_kzalloc(dev, sizeof(*larb), GFP_KERNEL);
150	if (!larb)
151		return -ENOMEM;
152
153	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
154	larb->base = devm_ioremap_resource(dev, res);
155	if (IS_ERR(larb->base))
156		return PTR_ERR(larb->base);
157
158	larb->smi.clk_apb = devm_clk_get(dev, "apb");
159	if (IS_ERR(larb->smi.clk_apb))
160		return PTR_ERR(larb->smi.clk_apb);
161
162	larb->smi.clk_smi = devm_clk_get(dev, "smi");
163	if (IS_ERR(larb->smi.clk_smi))
164		return PTR_ERR(larb->smi.clk_smi);
165	larb->smi.dev = dev;
166
167	smi_node = of_parse_phandle(dev->of_node, "mediatek,smi", 0);
168	if (!smi_node)
169		return -EINVAL;
170
171	smi_pdev = of_find_device_by_node(smi_node);
172	of_node_put(smi_node);
173	if (smi_pdev) {
174		larb->smi_common_dev = &smi_pdev->dev;
175	} else {
176		dev_err(dev, "Failed to get the smi_common device\n");
177		return -EINVAL;
178	}
179
180	pm_runtime_enable(dev);
181	platform_set_drvdata(pdev, larb);
182	return component_add(dev, &mtk_smi_larb_component_ops);
183}
184
185static int mtk_smi_larb_remove(struct platform_device *pdev)
186{
187	pm_runtime_disable(&pdev->dev);
188	component_del(&pdev->dev, &mtk_smi_larb_component_ops);
189	return 0;
190}
191
192static const struct of_device_id mtk_smi_larb_of_ids[] = {
193	{ .compatible = "mediatek,mt8173-smi-larb",},
194	{}
195};
196
197static struct platform_driver mtk_smi_larb_driver = {
198	.probe	= mtk_smi_larb_probe,
199	.remove = mtk_smi_larb_remove,
200	.driver	= {
201		.name = "mtk-smi-larb",
202		.of_match_table = mtk_smi_larb_of_ids,
203	}
204};
205
206static int mtk_smi_common_probe(struct platform_device *pdev)
207{
208	struct device *dev = &pdev->dev;
209	struct mtk_smi *common;
210
211	if (!dev->pm_domain)
212		return -EPROBE_DEFER;
213
214	common = devm_kzalloc(dev, sizeof(*common), GFP_KERNEL);
215	if (!common)
216		return -ENOMEM;
217	common->dev = dev;
218
219	common->clk_apb = devm_clk_get(dev, "apb");
220	if (IS_ERR(common->clk_apb))
221		return PTR_ERR(common->clk_apb);
222
223	common->clk_smi = devm_clk_get(dev, "smi");
224	if (IS_ERR(common->clk_smi))
225		return PTR_ERR(common->clk_smi);
226
227	pm_runtime_enable(dev);
228	platform_set_drvdata(pdev, common);
229	return 0;
230}
231
232static int mtk_smi_common_remove(struct platform_device *pdev)
233{
234	pm_runtime_disable(&pdev->dev);
235	return 0;
236}
237
238static const struct of_device_id mtk_smi_common_of_ids[] = {
239	{ .compatible = "mediatek,mt8173-smi-common", },
240	{}
241};
242
243static struct platform_driver mtk_smi_common_driver = {
244	.probe	= mtk_smi_common_probe,
245	.remove = mtk_smi_common_remove,
246	.driver	= {
247		.name = "mtk-smi-common",
248		.of_match_table = mtk_smi_common_of_ids,
249	}
250};
251
252static int __init mtk_smi_init(void)
253{
254	int ret;
255
256	ret = platform_driver_register(&mtk_smi_common_driver);
257	if (ret != 0) {
258		pr_err("Failed to register SMI driver\n");
259		return ret;
260	}
261
262	ret = platform_driver_register(&mtk_smi_larb_driver);
263	if (ret != 0) {
264		pr_err("Failed to register SMI-LARB driver\n");
265		goto err_unreg_smi;
266	}
267	return ret;
268
269err_unreg_smi:
270	platform_driver_unregister(&mtk_smi_common_driver);
271	return ret;
272}
273subsys_initcall(mtk_smi_init);