1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3 * Copyright 2019 NXP
4 * Author: Daniel Baluta <daniel.baluta@nxp.com>
5 *
6 * Implementation of the DSP IPC interface (host side)
7 */
8
9 #include <linux/firmware/imx/dsp.h>
10 #include <linux/kernel.h>
11 #include <linux/mailbox_client.h>
12 #include <linux/module.h>
13 #include <linux/platform_device.h>
14 #include <linux/slab.h>
15
16 /*
17 * imx_dsp_ring_doorbell - triggers an interrupt on the other side (DSP)
18 *
19 * @dsp: DSP IPC handle
20 * @chan_idx: index of the channel where to trigger the interrupt
21 *
22 * Returns non-negative value for success, negative value for error
23 */
imx_dsp_ring_doorbell(struct imx_dsp_ipc * ipc,unsigned int idx)24 int imx_dsp_ring_doorbell(struct imx_dsp_ipc *ipc, unsigned int idx)
25 {
26 int ret;
27 struct imx_dsp_chan *dsp_chan;
28
29 if (idx >= DSP_MU_CHAN_NUM)
30 return -EINVAL;
31
32 dsp_chan = &ipc->chans[idx];
33 ret = mbox_send_message(dsp_chan->ch, NULL);
34 if (ret < 0)
35 return ret;
36
37 return 0;
38 }
39 EXPORT_SYMBOL(imx_dsp_ring_doorbell);
40
41 /*
42 * imx_dsp_handle_rx - rx callback used by imx mailbox
43 *
44 * @c: mbox client
45 * @msg: message received
46 *
47 * Users of DSP IPC will need to privde handle_reply and handle_request
48 * callbacks.
49 */
imx_dsp_handle_rx(struct mbox_client * c,void * msg)50 static void imx_dsp_handle_rx(struct mbox_client *c, void *msg)
51 {
52 struct imx_dsp_chan *chan = container_of(c, struct imx_dsp_chan, cl);
53
54 if (chan->idx == 0) {
55 chan->ipc->ops->handle_reply(chan->ipc);
56 } else {
57 chan->ipc->ops->handle_request(chan->ipc);
58 imx_dsp_ring_doorbell(chan->ipc, 1);
59 }
60 }
61
imx_dsp_request_channel(struct imx_dsp_ipc * dsp_ipc,int idx)62 struct mbox_chan *imx_dsp_request_channel(struct imx_dsp_ipc *dsp_ipc, int idx)
63 {
64 struct imx_dsp_chan *dsp_chan;
65
66 if (idx >= DSP_MU_CHAN_NUM)
67 return ERR_PTR(-EINVAL);
68
69 dsp_chan = &dsp_ipc->chans[idx];
70 dsp_chan->ch = mbox_request_channel_byname(&dsp_chan->cl, dsp_chan->name);
71 return dsp_chan->ch;
72 }
73 EXPORT_SYMBOL(imx_dsp_request_channel);
74
imx_dsp_free_channel(struct imx_dsp_ipc * dsp_ipc,int idx)75 void imx_dsp_free_channel(struct imx_dsp_ipc *dsp_ipc, int idx)
76 {
77 struct imx_dsp_chan *dsp_chan;
78
79 if (idx >= DSP_MU_CHAN_NUM)
80 return;
81
82 dsp_chan = &dsp_ipc->chans[idx];
83 mbox_free_channel(dsp_chan->ch);
84 }
85 EXPORT_SYMBOL(imx_dsp_free_channel);
86
imx_dsp_setup_channels(struct imx_dsp_ipc * dsp_ipc)87 static int imx_dsp_setup_channels(struct imx_dsp_ipc *dsp_ipc)
88 {
89 struct device *dev = dsp_ipc->dev;
90 struct imx_dsp_chan *dsp_chan;
91 struct mbox_client *cl;
92 char *chan_name;
93 int ret;
94 int i, j;
95
96 for (i = 0; i < DSP_MU_CHAN_NUM; i++) {
97 if (i < 2)
98 chan_name = kasprintf(GFP_KERNEL, "txdb%d", i);
99 else
100 chan_name = kasprintf(GFP_KERNEL, "rxdb%d", i - 2);
101
102 if (!chan_name)
103 return -ENOMEM;
104
105 dsp_chan = &dsp_ipc->chans[i];
106 dsp_chan->name = chan_name;
107 cl = &dsp_chan->cl;
108 cl->dev = dev;
109 cl->tx_block = false;
110 cl->knows_txdone = true;
111 cl->rx_callback = imx_dsp_handle_rx;
112
113 dsp_chan->ipc = dsp_ipc;
114 dsp_chan->idx = i % 2;
115 dsp_chan->ch = mbox_request_channel_byname(cl, chan_name);
116 if (IS_ERR(dsp_chan->ch)) {
117 ret = PTR_ERR(dsp_chan->ch);
118 if (ret != -EPROBE_DEFER)
119 dev_err(dev, "Failed to request mbox chan %s ret %d\n",
120 chan_name, ret);
121 kfree(dsp_chan->name);
122 goto out;
123 }
124
125 dev_dbg(dev, "request mbox chan %s\n", chan_name);
126 }
127
128 return 0;
129 out:
130 for (j = 0; j < i; j++) {
131 dsp_chan = &dsp_ipc->chans[j];
132 mbox_free_channel(dsp_chan->ch);
133 kfree(dsp_chan->name);
134 }
135
136 return ret;
137 }
138
imx_dsp_probe(struct platform_device * pdev)139 static int imx_dsp_probe(struct platform_device *pdev)
140 {
141 struct device *dev = &pdev->dev;
142 struct imx_dsp_ipc *dsp_ipc;
143 int ret;
144
145 device_set_of_node_from_dev(&pdev->dev, pdev->dev.parent);
146
147 dsp_ipc = devm_kzalloc(dev, sizeof(*dsp_ipc), GFP_KERNEL);
148 if (!dsp_ipc)
149 return -ENOMEM;
150
151 dsp_ipc->dev = dev;
152 dev_set_drvdata(dev, dsp_ipc);
153
154 ret = imx_dsp_setup_channels(dsp_ipc);
155 if (ret < 0)
156 return ret;
157
158 dev_info(dev, "NXP i.MX DSP IPC initialized\n");
159
160 return 0;
161 }
162
imx_dsp_remove(struct platform_device * pdev)163 static int imx_dsp_remove(struct platform_device *pdev)
164 {
165 struct imx_dsp_chan *dsp_chan;
166 struct imx_dsp_ipc *dsp_ipc;
167 int i;
168
169 dsp_ipc = dev_get_drvdata(&pdev->dev);
170
171 for (i = 0; i < DSP_MU_CHAN_NUM; i++) {
172 dsp_chan = &dsp_ipc->chans[i];
173 mbox_free_channel(dsp_chan->ch);
174 kfree(dsp_chan->name);
175 }
176
177 return 0;
178 }
179
180 static struct platform_driver imx_dsp_driver = {
181 .driver = {
182 .name = "imx-dsp",
183 },
184 .probe = imx_dsp_probe,
185 .remove = imx_dsp_remove,
186 };
187 builtin_platform_driver(imx_dsp_driver);
188
189 MODULE_AUTHOR("Daniel Baluta <daniel.baluta@nxp.com>");
190 MODULE_DESCRIPTION("IMX DSP IPC protocol driver");
191 MODULE_LICENSE("GPL v2");
192