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