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 
25 struct 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 
32 struct am654_hbmc_priv {
33 	struct hyperbus_ctlr ctlr;
34 	struct hyperbus_device hbdev;
35 	struct mux_control *mux_ctrl;
36 };
37 
am654_hbmc_calibrate(struct hyperbus_device * hbdev)38 static 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 
am654_hbmc_dma_callback(void * param)66 static 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 
am654_hbmc_dma_read(struct am654_hbmc_device_priv * priv,void * to,unsigned long from,ssize_t len)73 static 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 
119 unmap_dma:
120 	dma_unmap_single(rx_chan->device->dev, dma_dst, len, DMA_FROM_DEVICE);
121 	return ret;
122 }
123 
am654_hbmc_read(struct hyperbus_device * hbdev,void * to,unsigned long from,ssize_t len)124 static 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 
133 static const struct hyperbus_ops am654_hbmc_ops = {
134 	.calibrate = am654_hbmc_calibrate,
135 	.copy_from = am654_hbmc_read,
136 };
137 
am654_hbmc_request_mmap_dma(struct am654_hbmc_device_priv * priv)138 static 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 
am654_hbmc_probe(struct platform_device * pdev)159 static 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;
223 release_dma:
224 	if (dev_priv->rx_chan)
225 		dma_release_channel(dev_priv->rx_chan);
226 disable_mux:
227 	if (priv->mux_ctrl)
228 		mux_control_deselect(priv->mux_ctrl);
229 	return ret;
230 }
231 
am654_hbmc_remove(struct platform_device * pdev)232 static 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 
248 static const struct of_device_id am654_hbmc_dt_ids[] = {
249 	{
250 		.compatible = "ti,am654-hbmc",
251 	},
252 	{ /* end of table */ }
253 };
254 
255 MODULE_DEVICE_TABLE(of, am654_hbmc_dt_ids);
256 
257 static 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 
266 module_platform_driver(am654_hbmc_platform_driver);
267 
268 MODULE_DESCRIPTION("HBMC driver for AM654 SoC");
269 MODULE_LICENSE("GPL v2");
270 MODULE_ALIAS("platform:hbmc-am654");
271 MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
272