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 goto put_node;
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 ret = PTR_ERR(control);
184 goto put_node;
185 }
186
187 ret = mux_control_select(control, 1);
188 if (ret) {
189 dev_err(dev, "Failed to select HBMC mux\n");
190 goto put_node;
191 }
192 priv->mux_ctrl = control;
193 }
194
195 priv->hbdev.map.size = resource_size(&res);
196 priv->hbdev.map.virt = devm_ioremap_resource(dev, &res);
197 if (IS_ERR(priv->hbdev.map.virt)) {
198 ret = PTR_ERR(priv->hbdev.map.virt);
199 goto disable_mux;
200 }
201
202 priv->ctlr.dev = dev;
203 priv->ctlr.ops = &am654_hbmc_ops;
204 priv->hbdev.ctlr = &priv->ctlr;
205
206 dev_priv = devm_kzalloc(dev, sizeof(*dev_priv), GFP_KERNEL);
207 if (!dev_priv) {
208 ret = -ENOMEM;
209 goto disable_mux;
210 }
211
212 priv->hbdev.priv = dev_priv;
213 dev_priv->device_base = res.start;
214 dev_priv->ctlr = &priv->ctlr;
215
216 ret = am654_hbmc_request_mmap_dma(dev_priv);
217 if (ret)
218 goto disable_mux;
219
220 ret = hyperbus_register_device(&priv->hbdev);
221 if (ret) {
222 dev_err(dev, "failed to register controller\n");
223 goto release_dma;
224 }
225
226 return 0;
227 release_dma:
228 if (dev_priv->rx_chan)
229 dma_release_channel(dev_priv->rx_chan);
230 disable_mux:
231 if (priv->mux_ctrl)
232 mux_control_deselect(priv->mux_ctrl);
233 put_node:
234 of_node_put(priv->hbdev.np);
235 return ret;
236 }
237
am654_hbmc_remove(struct platform_device * pdev)238 static void am654_hbmc_remove(struct platform_device *pdev)
239 {
240 struct am654_hbmc_priv *priv = platform_get_drvdata(pdev);
241 struct am654_hbmc_device_priv *dev_priv = priv->hbdev.priv;
242
243 hyperbus_unregister_device(&priv->hbdev);
244
245 if (priv->mux_ctrl)
246 mux_control_deselect(priv->mux_ctrl);
247
248 if (dev_priv->rx_chan)
249 dma_release_channel(dev_priv->rx_chan);
250 of_node_put(priv->hbdev.np);
251 }
252
253 static const struct of_device_id am654_hbmc_dt_ids[] = {
254 {
255 .compatible = "ti,am654-hbmc",
256 },
257 { /* end of table */ }
258 };
259
260 MODULE_DEVICE_TABLE(of, am654_hbmc_dt_ids);
261
262 static struct platform_driver am654_hbmc_platform_driver = {
263 .probe = am654_hbmc_probe,
264 .remove_new = am654_hbmc_remove,
265 .driver = {
266 .name = "hbmc-am654",
267 .of_match_table = am654_hbmc_dt_ids,
268 },
269 };
270
271 module_platform_driver(am654_hbmc_platform_driver);
272
273 MODULE_DESCRIPTION("HBMC driver for AM654 SoC");
274 MODULE_LICENSE("GPL v2");
275 MODULE_ALIAS("platform:hbmc-am654");
276 MODULE_AUTHOR("Vignesh Raghavendra <vigneshr@ti.com>");
277