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(sizeof(*sys_controller), GFP_KERNEL);
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 return dev_err_probe(dev, PTR_ERR(sys_controller->flash), "Failed to get flash\n");
147
148 no_flash:
149 sys_controller->client.dev = dev;
150 sys_controller->client.rx_callback = mpfs_sys_controller_rx_callback;
151 sys_controller->client.tx_block = 1U;
152 sys_controller->client.tx_tout = msecs_to_jiffies(MPFS_SYS_CTRL_TIMEOUT_MS);
153
154 sys_controller->chan = mbox_request_channel(&sys_controller->client, 0);
155 if (IS_ERR(sys_controller->chan)) {
156 ret = dev_err_probe(dev, PTR_ERR(sys_controller->chan),
157 "Failed to get mbox channel\n");
158 kfree(sys_controller);
159 return ret;
160 }
161
162 init_completion(&sys_controller->c);
163 kref_init(&sys_controller->consumers);
164
165 platform_set_drvdata(pdev, sys_controller);
166
167
168 for (i = 0; i < ARRAY_SIZE(subdevs); i++) {
169 subdevs[i].dev.parent = dev;
170 if (platform_device_register(&subdevs[i]))
171 dev_warn(dev, "Error registering sub device %s\n", subdevs[i].name);
172 }
173
174 dev_info(&pdev->dev, "Registered MPFS system controller\n");
175
176 return 0;
177 }
178
mpfs_sys_controller_remove(struct platform_device * pdev)179 static void mpfs_sys_controller_remove(struct platform_device *pdev)
180 {
181 struct mpfs_sys_controller *sys_controller = platform_get_drvdata(pdev);
182
183 mpfs_sys_controller_put(sys_controller);
184 }
185
186 static const struct of_device_id mpfs_sys_controller_of_match[] = {
187 {.compatible = "microchip,mpfs-sys-controller", },
188 {},
189 };
190 MODULE_DEVICE_TABLE(of, mpfs_sys_controller_of_match);
191
mpfs_sys_controller_get(struct device * dev)192 struct mpfs_sys_controller *mpfs_sys_controller_get(struct device *dev)
193 {
194 const struct of_device_id *match;
195 struct mpfs_sys_controller *sys_controller;
196 int ret;
197
198 if (!dev->parent)
199 goto err_no_device;
200
201 match = of_match_node(mpfs_sys_controller_of_match, dev->parent->of_node);
202 of_node_put(dev->parent->of_node);
203 if (!match)
204 goto err_no_device;
205
206 sys_controller = dev_get_drvdata(dev->parent);
207 if (!sys_controller)
208 goto err_bad_device;
209
210 if (!kref_get_unless_zero(&sys_controller->consumers))
211 goto err_bad_device;
212
213 ret = devm_add_action_or_reset(dev, mpfs_sys_controller_put, sys_controller);
214 if (ret)
215 return ERR_PTR(ret);
216
217 return sys_controller;
218
219 err_no_device:
220 dev_dbg(dev, "Parent device was not an MPFS system controller\n");
221 return ERR_PTR(-ENODEV);
222
223 err_bad_device:
224 dev_dbg(dev, "MPFS system controller found but could not register as a sub device\n");
225 return ERR_PTR(-EPROBE_DEFER);
226 }
227 EXPORT_SYMBOL(mpfs_sys_controller_get);
228
229 static struct platform_driver mpfs_sys_controller_driver = {
230 .driver = {
231 .name = "mpfs-sys-controller",
232 .of_match_table = mpfs_sys_controller_of_match,
233 },
234 .probe = mpfs_sys_controller_probe,
235 .remove_new = mpfs_sys_controller_remove,
236 };
237 module_platform_driver(mpfs_sys_controller_driver);
238
239 MODULE_LICENSE("GPL v2");
240 MODULE_AUTHOR("Conor Dooley <conor.dooley@microchip.com>");
241 MODULE_DESCRIPTION("MPFS system controller driver");
242