1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright 2019 NXP
4 *
5 * Implementation of the SCU IRQ functions using MU.
6 *
7 */
8
9#include <dt-bindings/firmware/imx/rsrc.h>
10#include <linux/firmware/imx/ipc.h>
11#include <linux/firmware/imx/sci.h>
12#include <linux/mailbox_client.h>
13#include <linux/suspend.h>
14
15#define IMX_SC_IRQ_FUNC_ENABLE	1
16#define IMX_SC_IRQ_FUNC_STATUS	2
17#define IMX_SC_IRQ_NUM_GROUP	4
18
19static u32 mu_resource_id;
20
21struct imx_sc_msg_irq_get_status {
22	struct imx_sc_rpc_msg hdr;
23	union {
24		struct {
25			u16 resource;
26			u8 group;
27			u8 reserved;
28		} __packed req;
29		struct {
30			u32 status;
31		} resp;
32	} data;
33};
34
35struct imx_sc_msg_irq_enable {
36	struct imx_sc_rpc_msg hdr;
37	u32 mask;
38	u16 resource;
39	u8 group;
40	u8 enable;
41} __packed;
42
43static struct imx_sc_ipc *imx_sc_irq_ipc_handle;
44static struct work_struct imx_sc_irq_work;
45static ATOMIC_NOTIFIER_HEAD(imx_scu_irq_notifier_chain);
46
47int imx_scu_irq_register_notifier(struct notifier_block *nb)
48{
49	return atomic_notifier_chain_register(
50		&imx_scu_irq_notifier_chain, nb);
51}
52EXPORT_SYMBOL(imx_scu_irq_register_notifier);
53
54int imx_scu_irq_unregister_notifier(struct notifier_block *nb)
55{
56	return atomic_notifier_chain_unregister(
57		&imx_scu_irq_notifier_chain, nb);
58}
59EXPORT_SYMBOL(imx_scu_irq_unregister_notifier);
60
61static int imx_scu_irq_notifier_call_chain(unsigned long status, u8 *group)
62{
63	return atomic_notifier_call_chain(&imx_scu_irq_notifier_chain,
64		status, (void *)group);
65}
66
67static void imx_scu_irq_work_handler(struct work_struct *work)
68{
69	struct imx_sc_msg_irq_get_status msg;
70	struct imx_sc_rpc_msg *hdr = &msg.hdr;
71	u32 irq_status;
72	int ret;
73	u8 i;
74
75	for (i = 0; i < IMX_SC_IRQ_NUM_GROUP; i++) {
76		hdr->ver = IMX_SC_RPC_VERSION;
77		hdr->svc = IMX_SC_RPC_SVC_IRQ;
78		hdr->func = IMX_SC_IRQ_FUNC_STATUS;
79		hdr->size = 2;
80
81		msg.data.req.resource = mu_resource_id;
82		msg.data.req.group = i;
83
84		ret = imx_scu_call_rpc(imx_sc_irq_ipc_handle, &msg, true);
85		if (ret) {
86			pr_err("get irq group %d status failed, ret %d\n",
87			       i, ret);
88			return;
89		}
90
91		irq_status = msg.data.resp.status;
92		if (!irq_status)
93			continue;
94
95		pm_system_wakeup();
96		imx_scu_irq_notifier_call_chain(irq_status, &i);
97	}
98}
99
100int imx_scu_irq_group_enable(u8 group, u32 mask, u8 enable)
101{
102	struct imx_sc_msg_irq_enable msg;
103	struct imx_sc_rpc_msg *hdr = &msg.hdr;
104	int ret;
105
106	if (!imx_sc_irq_ipc_handle)
107		return -EPROBE_DEFER;
108
109	hdr->ver = IMX_SC_RPC_VERSION;
110	hdr->svc = IMX_SC_RPC_SVC_IRQ;
111	hdr->func = IMX_SC_IRQ_FUNC_ENABLE;
112	hdr->size = 3;
113
114	msg.resource = mu_resource_id;
115	msg.group = group;
116	msg.mask = mask;
117	msg.enable = enable;
118
119	ret = imx_scu_call_rpc(imx_sc_irq_ipc_handle, &msg, true);
120	if (ret)
121		pr_err("enable irq failed, group %d, mask %d, ret %d\n",
122			group, mask, ret);
123
124	return ret;
125}
126EXPORT_SYMBOL(imx_scu_irq_group_enable);
127
128static void imx_scu_irq_callback(struct mbox_client *c, void *msg)
129{
130	schedule_work(&imx_sc_irq_work);
131}
132
133int imx_scu_enable_general_irq_channel(struct device *dev)
134{
135	struct of_phandle_args spec;
136	struct mbox_client *cl;
137	struct mbox_chan *ch;
138	int ret = 0, i = 0;
139
140	ret = imx_scu_get_handle(&imx_sc_irq_ipc_handle);
141	if (ret)
142		return ret;
143
144	cl = devm_kzalloc(dev, sizeof(*cl), GFP_KERNEL);
145	if (!cl)
146		return -ENOMEM;
147
148	cl->dev = dev;
149	cl->rx_callback = imx_scu_irq_callback;
150
151	/* SCU general IRQ uses general interrupt channel 3 */
152	ch = mbox_request_channel_byname(cl, "gip3");
153	if (IS_ERR(ch)) {
154		ret = PTR_ERR(ch);
155		dev_err(dev, "failed to request mbox chan gip3, ret %d\n", ret);
156		devm_kfree(dev, cl);
157		return ret;
158	}
159
160	INIT_WORK(&imx_sc_irq_work, imx_scu_irq_work_handler);
161
162	if (!of_parse_phandle_with_args(dev->of_node, "mboxes",
163				       "#mbox-cells", 0, &spec))
164		i = of_alias_get_id(spec.np, "mu");
165
166	/* use mu1 as general mu irq channel if failed */
167	if (i < 0)
168		i = 1;
169
170	mu_resource_id = IMX_SC_R_MU_0A + i;
171
172	return ret;
173}
174EXPORT_SYMBOL(imx_scu_enable_general_irq_channel);
175