1// SPDX-License-Identifier: GPL-2.0
2//
3// Copyright (C) 2019 Texas Instruments Incorporated - https://www.ti.com/
4// Author: Vignesh Raghavendra <vigneshr@ti.com>
5
6#include <linux/completion.h>
7#include <linux/dma-direction.h>
8#include <linux/dma-mapping.h>
9#include <linux/dmaengine.h>
10#include <linux/err.h>
11#include <linux/kernel.h>
12#include <linux/module.h>
13#include <linux/mtd/cfi.h>
14#include <linux/mtd/hyperbus.h>
15#include <linux/mtd/mtd.h>
16#include <linux/mux/consumer.h>
17#include <linux/of.h>
18#include <linux/of_address.h>
19#include <linux/platform_device.h>
20#include <linux/sched/task_stack.h>
21#include <linux/types.h>
22
23#define AM654_HBMC_CALIB_COUNT 25
24
25struct am654_hbmc_device_priv {
26	struct completion rx_dma_complete;
27	phys_addr_t device_base;
28	struct hyperbus_ctlr *ctlr;
29	struct dma_chan *rx_chan;
30};
31
32struct am654_hbmc_priv {
33	struct hyperbus_ctlr ctlr;
34	struct hyperbus_device hbdev;
35	struct mux_control *mux_ctrl;
36};
37
38static int am654_hbmc_calibrate(struct hyperbus_device *hbdev)
39{
40	struct map_info *map = &hbdev->map;
41	struct cfi_private cfi;
42	int count = AM654_HBMC_CALIB_COUNT;
43	int pass_count = 0;
44	int ret;
45
46	cfi.interleave = 1;
47	cfi.device_type = CFI_DEVICETYPE_X16;
48	cfi_send_gen_cmd(0xF0, 0, 0, map, &cfi, cfi.device_type, NULL);
49	cfi_send_gen_cmd(0x98, 0x55, 0, map, &cfi, cfi.device_type, NULL);
50
51	while (count--) {
52		ret = cfi_qry_present(map, 0, &cfi);
53		if (ret)
54			pass_count++;
55		else
56			pass_count = 0;
57		if (pass_count == 5)
58			break;
59	}
60
61	cfi_qry_mode_off(0, map, &cfi);
62
63	return ret;
64}
65
66static void am654_hbmc_dma_callback(void *param)
67{
68	struct am654_hbmc_device_priv *priv = param;
69
70	complete(&priv->rx_dma_complete);
71}
72
73static int am654_hbmc_dma_read(struct am654_hbmc_device_priv *priv, void *to,
74			       unsigned long from, ssize_t len)
75
76{
77	enum dma_ctrl_flags flags = DMA_CTRL_ACK | DMA_PREP_INTERRUPT;
78	struct dma_chan *rx_chan = priv->rx_chan;
79	struct dma_async_tx_descriptor *tx;
80	dma_addr_t dma_dst, dma_src;
81	dma_cookie_t cookie;
82	int ret;
83
84	if (!priv->rx_chan || !virt_addr_valid(to) || object_is_on_stack(to))
85		return -EINVAL;
86
87	dma_dst = dma_map_single(rx_chan->device->dev, to, len, DMA_FROM_DEVICE);
88	if (dma_mapping_error(rx_chan->device->dev, dma_dst)) {
89		dev_dbg(priv->ctlr->dev, "DMA mapping failed\n");
90		return -EIO;
91	}
92
93	dma_src = priv->device_base + from;
94	tx = dmaengine_prep_dma_memcpy(rx_chan, dma_dst, dma_src, len, flags);
95	if (!tx) {
96		dev_err(priv->ctlr->dev, "device_prep_dma_memcpy error\n");
97		ret = -EIO;
98		goto unmap_dma;
99	}
100
101	reinit_completion(&priv->rx_dma_complete);
102	tx->callback = am654_hbmc_dma_callback;
103	tx->callback_param = priv;
104	cookie = dmaengine_submit(tx);
105
106	ret = dma_submit_error(cookie);
107	if (ret) {
108		dev_err(priv->ctlr->dev, "dma_submit_error %d\n", cookie);
109		goto unmap_dma;
110	}
111
112	dma_async_issue_pending(rx_chan);
113	if (!wait_for_completion_timeout(&priv->rx_dma_complete,  msecs_to_jiffies(len + 1000))) {
114		dmaengine_terminate_sync(rx_chan);
115		dev_err(priv->ctlr->dev, "DMA wait_for_completion_timeout\n");
116		ret = -ETIMEDOUT;
117	}
118
119unmap_dma:
120	dma_unmap_single(rx_chan->device->dev, dma_dst, len, DMA_FROM_DEVICE);
121	return ret;
122}
123
124static void am654_hbmc_read(struct hyperbus_device *hbdev, void *to,
125			    unsigned long from, ssize_t len)
126{
127	struct am654_hbmc_device_priv *priv = hbdev->priv;
128
129	if (len < SZ_1K || am654_hbmc_dma_read(priv, to, from, len))
130		memcpy_fromio(to, hbdev->map.virt + from, len);
131}
132
133static const struct hyperbus_ops am654_hbmc_ops = {
134	.calibrate = am654_hbmc_calibrate,
135	.copy_from = am654_hbmc_read,
136};
137
138static int am654_hbmc_request_mmap_dma(struct am654_hbmc_device_priv *priv)
139{
140	struct dma_chan *rx_chan;
141	dma_cap_mask_t mask;
142
143	dma_cap_zero(mask);
144	dma_cap_set(DMA_MEMCPY, mask);
145
146	rx_chan = dma_request_chan_by_mask(&mask);
147	if (IS_ERR(rx_chan)) {
148		if (PTR_ERR(rx_chan) == -EPROBE_DEFER)
149			return -EPROBE_DEFER;
150		dev_dbg(priv->ctlr->dev, "No DMA channel available\n");
151		return 0;
152	}
153	priv->rx_chan = rx_chan;
154	init_completion(&priv->rx_dma_complete);
155
156	return 0;
157}
158
159static int am654_hbmc_probe(struct platform_device *pdev)
160{
161	struct device_node *np = pdev->dev.of_node;
162	struct am654_hbmc_device_priv *dev_priv;
163	struct device *dev = &pdev->dev;
164	struct am654_hbmc_priv *priv;
165	struct resource res;
166	int ret;
167
168	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
169	if (!priv)
170		return -ENOMEM;
171
172	platform_set_drvdata(pdev, priv);
173
174	priv->hbdev.np = of_get_next_child(np, NULL);
175	ret = of_address_to_resource(priv->hbdev.np, 0, &res);
176	if (ret)
177		return ret;
178
179	if (of_property_read_bool(dev->of_node, "mux-controls")) {
180		struct mux_control *control = devm_mux_control_get(dev, NULL);
181
182		if (IS_ERR(control))
183			return PTR_ERR(control);
184
185		ret = mux_control_select(control, 1);
186		if (ret) {
187			dev_err(dev, "Failed to select HBMC mux\n");
188			return ret;
189		}
190		priv->mux_ctrl = control;
191	}
192
193	priv->hbdev.map.size = resource_size(&res);
194	priv->hbdev.map.virt = devm_ioremap_resource(dev, &res);
195	if (IS_ERR(priv->hbdev.map.virt))
196		return PTR_ERR(priv->hbdev.map.virt);
197
198	priv->ctlr.dev = dev;
199	priv->ctlr.ops = &am654_hbmc_ops;
200	priv->hbdev.ctlr = &priv->ctlr;
201
202	dev_priv = devm_kzalloc(dev, sizeof(*dev_priv), GFP_KERNEL);
203	if (!dev_priv) {
204		ret = -ENOMEM;
205		goto disable_mux;
206	}
207
208	priv->hbdev.priv = dev_priv;
209	dev_priv->device_base = res.start;
210	dev_priv->ctlr = &priv->ctlr;
211
212	ret = am654_hbmc_request_mmap_dma(dev_priv);
213	if (ret)
214		goto disable_mux;
215
216	ret = hyperbus_register_device(&priv->hbdev);
217	if (ret) {
218		dev_err(dev, "failed to register controller\n");
219		goto release_dma;
220	}
221
222	return 0;
223release_dma:
224	if (dev_priv->rx_chan)
225		dma_release_channel(dev_priv->rx_chan);
226disable_mux:
227	if (priv->mux_ctrl)
228		mux_control_deselect(priv->mux_ctrl);
229	return ret;
230}
231
232static int am654_hbmc_remove(struct platform_device *pdev)
233{
234	struct am654_hbmc_priv *priv = platform_get_drvdata(pdev);
235	struct am654_hbmc_device_priv *dev_priv = priv->hbdev.priv;
236
237	hyperbus_unregister_device(&priv->hbdev);
238
239	if (priv->mux_ctrl)
240		mux_control_deselect(priv->mux_ctrl);
241
242	if (dev_priv->rx_chan)
243		dma_release_channel(dev_priv->rx_chan);
244
245	return 0;
246}
247
248static const struct of_device_id am654_hbmc_dt_ids[] = {
249	{
250		.compatible = "ti,am654-hbmc",
251	},
252	{ /* end of table */ }
253};
254
255MODULE_DEVICE_TABLE(of, am654_hbmc_dt_ids);
256
257static struct platform_driver am654_hbmc_platform_driver = {
258	.probe = am654_hbmc_probe,
259	.remove = am654_hbmc_remove,
260	.driver = {
261		.name = "hbmc-am654",
262		.of_match_table = am654_hbmc_dt_ids,
263	},
264};
265
266module_platform_driver(am654_hbmc_platform_driver);
267
268MODULE_DESCRIPTION("HBMC driver for AM654 SoC");
269MODULE_LICENSE("GPL v2");
270MODULE_ALIAS("platform:hbmc-am654");
271MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
272