1// SPDX-License-Identifier: GPL-2.0+
  2/*
  3 * Copyright 2019,2023 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/kobject.h>
 13#include <linux/mailbox_client.h>
 14#include <linux/of.h>
 15#include <linux/suspend.h>
 16#include <linux/sysfs.h>
 17
 18#define IMX_SC_IRQ_FUNC_ENABLE	1
 19#define IMX_SC_IRQ_FUNC_STATUS	2
 20#define IMX_SC_IRQ_NUM_GROUP	9
 21
 22static u32 mu_resource_id;
 23
 24struct imx_sc_msg_irq_get_status {
 25	struct imx_sc_rpc_msg hdr;
 26	union {
 27		struct {
 28			u16 resource;
 29			u8 group;
 30			u8 reserved;
 31		} __packed req;
 32		struct {
 33			u32 status;
 34		} resp;
 35	} data;
 36};
 37
 38struct imx_sc_msg_irq_enable {
 39	struct imx_sc_rpc_msg hdr;
 40	u32 mask;
 41	u16 resource;
 42	u8 group;
 43	u8 enable;
 44} __packed;
 45
 46struct scu_wakeup {
 47	u32 mask;
 48	u32 wakeup_src;
 49	bool valid;
 50};
 51
 52/* Sysfs functions */
 53static struct kobject *wakeup_obj;
 54static ssize_t wakeup_source_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf);
 55static struct kobj_attribute wakeup_source_attr =
 56		__ATTR(wakeup_src, 0660, wakeup_source_show, NULL);
 57
 58static struct scu_wakeup scu_irq_wakeup[IMX_SC_IRQ_NUM_GROUP];
 59
 60static struct imx_sc_ipc *imx_sc_irq_ipc_handle;
 61static struct work_struct imx_sc_irq_work;
 62static BLOCKING_NOTIFIER_HEAD(imx_scu_irq_notifier_chain);
 63
 64int imx_scu_irq_register_notifier(struct notifier_block *nb)
 65{
 66	return blocking_notifier_chain_register(
 67		&imx_scu_irq_notifier_chain, nb);
 68}
 69EXPORT_SYMBOL(imx_scu_irq_register_notifier);
 70
 71int imx_scu_irq_unregister_notifier(struct notifier_block *nb)
 72{
 73	return blocking_notifier_chain_unregister(
 74		&imx_scu_irq_notifier_chain, nb);
 75}
 76EXPORT_SYMBOL(imx_scu_irq_unregister_notifier);
 77
 78static int imx_scu_irq_notifier_call_chain(unsigned long status, u8 *group)
 79{
 80	return blocking_notifier_call_chain(&imx_scu_irq_notifier_chain,
 81		status, (void *)group);
 82}
 83
 84static void imx_scu_irq_work_handler(struct work_struct *work)
 85{
 86	u32 irq_status;
 87	int ret;
 88	u8 i;
 89
 90	for (i = 0; i < IMX_SC_IRQ_NUM_GROUP; i++) {
 91		if (scu_irq_wakeup[i].mask) {
 92			scu_irq_wakeup[i].valid = false;
 93			scu_irq_wakeup[i].wakeup_src = 0;
 94		}
 95
 96		ret = imx_scu_irq_get_status(i, &irq_status);
 97		if (ret) {
 98			pr_err("get irq group %d status failed, ret %d\n",
 99			       i, ret);
100			return;
101		}
102
103		if (!irq_status)
104			continue;
105		if (scu_irq_wakeup[i].mask & irq_status) {
106			scu_irq_wakeup[i].valid = true;
107			scu_irq_wakeup[i].wakeup_src = irq_status & scu_irq_wakeup[i].mask;
108		} else {
109			scu_irq_wakeup[i].wakeup_src = irq_status;
110		}
111
112		pm_system_wakeup();
113		imx_scu_irq_notifier_call_chain(irq_status, &i);
114	}
115}
116
117int imx_scu_irq_get_status(u8 group, u32 *irq_status)
118{
119	struct imx_sc_msg_irq_get_status msg;
120	struct imx_sc_rpc_msg *hdr = &msg.hdr;
121	int ret;
122
123	hdr->ver = IMX_SC_RPC_VERSION;
124	hdr->svc = IMX_SC_RPC_SVC_IRQ;
125	hdr->func = IMX_SC_IRQ_FUNC_STATUS;
126	hdr->size = 2;
127
128	msg.data.req.resource = mu_resource_id;
129	msg.data.req.group = group;
130
131	ret = imx_scu_call_rpc(imx_sc_irq_ipc_handle, &msg, true);
132	if (ret)
133		return ret;
134
135	if (irq_status)
136		*irq_status = msg.data.resp.status;
137
138	return 0;
139}
140EXPORT_SYMBOL(imx_scu_irq_get_status);
141
142int imx_scu_irq_group_enable(u8 group, u32 mask, u8 enable)
143{
144	struct imx_sc_msg_irq_enable msg;
145	struct imx_sc_rpc_msg *hdr = &msg.hdr;
146	int ret;
147
148	if (!imx_sc_irq_ipc_handle)
149		return -EPROBE_DEFER;
150
151	hdr->ver = IMX_SC_RPC_VERSION;
152	hdr->svc = IMX_SC_RPC_SVC_IRQ;
153	hdr->func = IMX_SC_IRQ_FUNC_ENABLE;
154	hdr->size = 3;
155
156	msg.resource = mu_resource_id;
157	msg.group = group;
158	msg.mask = mask;
159	msg.enable = enable;
160
161	ret = imx_scu_call_rpc(imx_sc_irq_ipc_handle, &msg, true);
162	if (ret)
163		pr_err("enable irq failed, group %d, mask %d, ret %d\n",
164			group, mask, ret);
165
166	if (enable)
167		scu_irq_wakeup[group].mask |= mask;
168	else
169		scu_irq_wakeup[group].mask &= ~mask;
170
171	return ret;
172}
173EXPORT_SYMBOL(imx_scu_irq_group_enable);
174
175static void imx_scu_irq_callback(struct mbox_client *c, void *msg)
176{
177	schedule_work(&imx_sc_irq_work);
178}
179
180static ssize_t wakeup_source_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf)
181{
182	int i;
183
184	for (i = 0; i < IMX_SC_IRQ_NUM_GROUP; i++) {
185		if (!scu_irq_wakeup[i].wakeup_src)
186			continue;
187
188		if (scu_irq_wakeup[i].valid)
189			sprintf(buf, "Wakeup source group = %d, irq = 0x%x\n",
190				i, scu_irq_wakeup[i].wakeup_src);
191		else
192			sprintf(buf, "Spurious SCU wakeup, group = %d, irq = 0x%x\n",
193				i, scu_irq_wakeup[i].wakeup_src);
194	}
195
196	return strlen(buf);
197}
198
199int imx_scu_enable_general_irq_channel(struct device *dev)
200{
201	struct of_phandle_args spec;
202	struct mbox_client *cl;
203	struct mbox_chan *ch;
204	int ret = 0, i = 0;
205
206	ret = imx_scu_get_handle(&imx_sc_irq_ipc_handle);
207	if (ret)
208		return ret;
209
210	cl = devm_kzalloc(dev, sizeof(*cl), GFP_KERNEL);
211	if (!cl)
212		return -ENOMEM;
213
214	cl->dev = dev;
215	cl->rx_callback = imx_scu_irq_callback;
216
217	/* SCU general IRQ uses general interrupt channel 3 */
218	ch = mbox_request_channel_byname(cl, "gip3");
219	if (IS_ERR(ch)) {
220		ret = PTR_ERR(ch);
221		dev_err(dev, "failed to request mbox chan gip3, ret %d\n", ret);
222		devm_kfree(dev, cl);
223		return ret;
224	}
225
226	INIT_WORK(&imx_sc_irq_work, imx_scu_irq_work_handler);
227
228	if (!of_parse_phandle_with_args(dev->of_node, "mboxes",
229				       "#mbox-cells", 0, &spec))
230		i = of_alias_get_id(spec.np, "mu");
231
232	/* use mu1 as general mu irq channel if failed */
233	if (i < 0)
234		i = 1;
235
236	mu_resource_id = IMX_SC_R_MU_0A + i;
237
238	/* Create directory under /sysfs/firmware */
239	wakeup_obj = kobject_create_and_add("scu_wakeup_source", firmware_kobj);
240	if (!wakeup_obj) {
241		ret = -ENOMEM;
242		goto free_ch;
243	}
244
245	ret = sysfs_create_file(wakeup_obj, &wakeup_source_attr.attr);
246	if (ret) {
247		dev_err(dev, "Cannot create wakeup source src file......\n");
248		kobject_put(wakeup_obj);
249		goto free_ch;
250	}
251
252	return 0;
253
254free_ch:
255	mbox_free_channel(ch);
256
257	return ret;
258}
259EXPORT_SYMBOL(imx_scu_enable_general_irq_channel);