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 
19 static u32 mu_resource_id;
20 
21 struct 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 
35 struct 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 
43 static struct imx_sc_ipc *imx_sc_irq_ipc_handle;
44 static struct work_struct imx_sc_irq_work;
45 static ATOMIC_NOTIFIER_HEAD(imx_scu_irq_notifier_chain);
46 
47 int imx_scu_irq_register_notifier(struct notifier_block *nb)
48 {
49 	return atomic_notifier_chain_register(
50 		&imx_scu_irq_notifier_chain, nb);
51 }
52 EXPORT_SYMBOL(imx_scu_irq_register_notifier);
53 
54 int imx_scu_irq_unregister_notifier(struct notifier_block *nb)
55 {
56 	return atomic_notifier_chain_unregister(
57 		&imx_scu_irq_notifier_chain, nb);
58 }
59 EXPORT_SYMBOL(imx_scu_irq_unregister_notifier);
60 
61 static 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 
67 static 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 
100 int 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 }
126 EXPORT_SYMBOL(imx_scu_irq_group_enable);
127 
128 static void imx_scu_irq_callback(struct mbox_client *c, void *msg)
129 {
130 	schedule_work(&imx_sc_irq_work);
131 }
132 
133 int 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 }
174 EXPORT_SYMBOL(imx_scu_enable_general_irq_channel);
175