1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Microchip PolarFire SoC (MPFS) system controller driver
4 *
5 * Copyright (c) 2020-2021 Microchip Corporation. All rights reserved.
6 *
7 * Author: Conor Dooley <conor.dooley@microchip.com>
8 *
9 */
10
11 #include <linux/slab.h>
12 #include <linux/kref.h>
13 #include <linux/module.h>
14 #include <linux/jiffies.h>
15 #include <linux/mtd/mtd.h>
16 #include <linux/spi/spi.h>
17 #include <linux/interrupt.h>
18 #include <linux/of.h>
19 #include <linux/mailbox_client.h>
20 #include <linux/platform_device.h>
21 #include <soc/microchip/mpfs.h>
22
23 /*
24 * This timeout must be long, as some services (example: image authentication)
25 * take significant time to complete
26 */
27 #define MPFS_SYS_CTRL_TIMEOUT_MS 30000
28
29 static DEFINE_MUTEX(transaction_lock);
30
31 struct mpfs_sys_controller {
32 struct mbox_client client;
33 struct mbox_chan *chan;
34 struct completion c;
35 struct mtd_info *flash;
36 struct kref consumers;
37 };
38
mpfs_blocking_transaction(struct mpfs_sys_controller * sys_controller,struct mpfs_mss_msg * msg)39 int mpfs_blocking_transaction(struct mpfs_sys_controller *sys_controller, struct mpfs_mss_msg *msg)
40 {
41 unsigned long timeout = msecs_to_jiffies(MPFS_SYS_CTRL_TIMEOUT_MS);
42 int ret;
43
44 ret = mutex_lock_interruptible(&transaction_lock);
45 if (ret)
46 return ret;
47
48 reinit_completion(&sys_controller->c);
49
50 ret = mbox_send_message(sys_controller->chan, msg);
51 if (ret < 0) {
52 dev_warn(sys_controller->client.dev, "MPFS sys controller service timeout\n");
53 goto out;
54 }
55
56 /*
57 * Unfortunately, the system controller will only deliver an interrupt
58 * if a service succeeds. mbox_send_message() will block until the busy
59 * flag is gone. If the busy flag is gone but no interrupt has arrived
60 * to trigger the rx callback then the service can be deemed to have
61 * failed.
62 * The caller can then interrogate msg::response::resp_status to
63 * determine the cause of the failure.
64 * mbox_send_message() returns positive integers in the success path, so
65 * ret needs to be cleared if we do get an interrupt.
66 */
67 if (!wait_for_completion_timeout(&sys_controller->c, timeout)) {
68 ret = -EBADMSG;
69 dev_warn(sys_controller->client.dev,
70 "MPFS sys controller service failed with status: %d\n",
71 msg->response->resp_status);
72 } else {
73 ret = 0;
74 }
75
76 out:
77 mutex_unlock(&transaction_lock);
78
79 return ret;
80 }
81 EXPORT_SYMBOL(mpfs_blocking_transaction);
82
mpfs_sys_controller_rx_callback(struct mbox_client * client,void * msg)83 static void mpfs_sys_controller_rx_callback(struct mbox_client *client, void *msg)
84 {
85 struct mpfs_sys_controller *sys_controller =
86 container_of(client, struct mpfs_sys_controller, client);
87
88 complete(&sys_controller->c);
89 }
90
mpfs_sys_controller_delete(struct kref * kref)91 static void mpfs_sys_controller_delete(struct kref *kref)
92 {
93 struct mpfs_sys_controller *sys_controller =
94 container_of(kref, struct mpfs_sys_controller, consumers);
95
96 mbox_free_channel(sys_controller->chan);
97 kfree(sys_controller);
98 }
99
mpfs_sys_controller_put(void * data)100 static void mpfs_sys_controller_put(void *data)
101 {
102 struct mpfs_sys_controller *sys_controller = data;
103
104 kref_put(&sys_controller->consumers, mpfs_sys_controller_delete);
105 }
106
mpfs_sys_controller_get_flash(struct mpfs_sys_controller * mpfs_client)107 struct mtd_info *mpfs_sys_controller_get_flash(struct mpfs_sys_controller *mpfs_client)
108 {
109 return mpfs_client->flash;
110 }
111 EXPORT_SYMBOL(mpfs_sys_controller_get_flash);
112
113 static struct platform_device subdevs[] = {
114 {
115 .name = "mpfs-rng",
116 .id = -1,
117 },
118 {
119 .name = "mpfs-generic-service",
120 .id = -1,
121 },
122 {
123 .name = "mpfs-auto-update",
124 .id = -1,
125 },
126 };
127
mpfs_sys_controller_probe(struct platform_device * pdev)128 static int mpfs_sys_controller_probe(struct platform_device *pdev)
129 {
130 struct device *dev = &pdev->dev;
131 struct mpfs_sys_controller *sys_controller;
132 struct device_node *np;
133 int i, ret;
134
135 sys_controller = kzalloc_obj(*sys_controller);
136 if (!sys_controller)
137 return -ENOMEM;
138
139 np = of_parse_phandle(dev->of_node, "microchip,bitstream-flash", 0);
140 if (!np)
141 goto no_flash;
142
143 sys_controller->flash = of_get_mtd_device_by_node(np);
144 of_node_put(np);
145 if (IS_ERR(sys_controller->flash)) {
146 ret = dev_err_probe(dev, PTR_ERR(sys_controller->flash), "Failed to get flash\n");
147 goto out_free;
148 }
149
150 no_flash:
151 sys_controller->client.dev = dev;
152 sys_controller->client.rx_callback = mpfs_sys_controller_rx_callback;
153 sys_controller->client.tx_block = 1U;
154 sys_controller->client.tx_tout = msecs_to_jiffies(MPFS_SYS_CTRL_TIMEOUT_MS);
155
156 sys_controller->chan = mbox_request_channel(&sys_controller->client, 0);
157 if (IS_ERR(sys_controller->chan)) {
158 ret = dev_err_probe(dev, PTR_ERR(sys_controller->chan),
159 "Failed to get mbox channel\n");
160 goto out_free;
161 }
162
163 init_completion(&sys_controller->c);
164 kref_init(&sys_controller->consumers);
165
166 platform_set_drvdata(pdev, sys_controller);
167
168
169 for (i = 0; i < ARRAY_SIZE(subdevs); i++) {
170 subdevs[i].dev.parent = dev;
171 if (platform_device_register(&subdevs[i]))
172 dev_warn(dev, "Error registering sub device %s\n", subdevs[i].name);
173 }
174
175 dev_info(&pdev->dev, "Registered MPFS system controller\n");
176
177 return 0;
178
179 out_free:
180 kfree(sys_controller);
181 return ret;
182 }
183
mpfs_sys_controller_remove(struct platform_device * pdev)184 static void mpfs_sys_controller_remove(struct platform_device *pdev)
185 {
186 struct mpfs_sys_controller *sys_controller = platform_get_drvdata(pdev);
187
188 mpfs_sys_controller_put(sys_controller);
189 }
190
191 static const struct of_device_id mpfs_sys_controller_of_match[] = {
192 {.compatible = "microchip,mpfs-sys-controller", },
193 {},
194 };
195 MODULE_DEVICE_TABLE(of, mpfs_sys_controller_of_match);
196
mpfs_sys_controller_get(struct device * dev)197 struct mpfs_sys_controller *mpfs_sys_controller_get(struct device *dev)
198 {
199 const struct of_device_id *match;
200 struct mpfs_sys_controller *sys_controller;
201 int ret;
202
203 if (!dev->parent)
204 goto err_no_device;
205
206 match = of_match_node(mpfs_sys_controller_of_match, dev->parent->of_node);
207 of_node_put(dev->parent->of_node);
208 if (!match)
209 goto err_no_device;
210
211 sys_controller = dev_get_drvdata(dev->parent);
212 if (!sys_controller)
213 goto err_bad_device;
214
215 if (!kref_get_unless_zero(&sys_controller->consumers))
216 goto err_bad_device;
217
218 ret = devm_add_action_or_reset(dev, mpfs_sys_controller_put, sys_controller);
219 if (ret)
220 return ERR_PTR(ret);
221
222 return sys_controller;
223
224 err_no_device:
225 dev_dbg(dev, "Parent device was not an MPFS system controller\n");
226 return ERR_PTR(-ENODEV);
227
228 err_bad_device:
229 dev_dbg(dev, "MPFS system controller found but could not register as a sub device\n");
230 return ERR_PTR(-EPROBE_DEFER);
231 }
232 EXPORT_SYMBOL(mpfs_sys_controller_get);
233
234 static struct platform_driver mpfs_sys_controller_driver = {
235 .driver = {
236 .name = "mpfs-sys-controller",
237 .of_match_table = mpfs_sys_controller_of_match,
238 },
239 .probe = mpfs_sys_controller_probe,
240 .remove = mpfs_sys_controller_remove,
241 };
242 module_platform_driver(mpfs_sys_controller_driver);
243
244 MODULE_LICENSE("GPL v2");
245 MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");
246 MODULE_DESCRIPTION("MPFS system controller driver");
247