1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * APM X-Gene SLIMpro MailBox Driver
4 *
5 * Copyright (c) 2015, Applied Micro Circuits Corporation
6 * Author: Feng Kan fkan@apm.com
7 */
8 #include <linux/acpi.h>
9 #include <linux/delay.h>
10 #include <linux/interrupt.h>
11 #include <linux/io.h>
12 #include <linux/mailbox_controller.h>
13 #include <linux/module.h>
14 #include <linux/of.h>
15 #include <linux/platform_device.h>
16 #include <linux/spinlock.h>
17
18 #define MBOX_CON_NAME "slimpro-mbox"
19 #define MBOX_REG_SET_OFFSET 0x1000
20 #define MBOX_CNT 8
21 #define MBOX_STATUS_AVAIL_MASK BIT(16)
22 #define MBOX_STATUS_ACK_MASK BIT(0)
23
24 /* Configuration and Status Registers */
25 #define REG_DB_IN 0x00
26 #define REG_DB_DIN0 0x04
27 #define REG_DB_DIN1 0x08
28 #define REG_DB_OUT 0x10
29 #define REG_DB_DOUT0 0x14
30 #define REG_DB_DOUT1 0x18
31 #define REG_DB_STAT 0x20
32 #define REG_DB_STATMASK 0x24
33
34 /**
35 * X-Gene SlimPRO mailbox channel information
36 *
37 * @dev: Device to which it is attached
38 * @chan: Pointer to mailbox communication channel
39 * @reg: Base address to access channel registers
40 * @irq: Interrupt number of the channel
41 * @rx_msg: Received message storage
42 */
43 struct slimpro_mbox_chan {
44 struct device *dev;
45 struct mbox_chan *chan;
46 void __iomem *reg;
47 int irq;
48 u32 rx_msg[3];
49 };
50
51 /**
52 * X-Gene SlimPRO Mailbox controller data
53 *
54 * X-Gene SlimPRO Mailbox controller has 8 communication channels.
55 * Each channel has a separate IRQ number assigned to it.
56 *
57 * @mb_ctrl: Representation of the communication channel controller
58 * @mc: Array of SlimPRO mailbox channels of the controller
59 * @chans: Array of mailbox communication channels
60 *
61 */
62 struct slimpro_mbox {
63 struct mbox_controller mb_ctrl;
64 struct slimpro_mbox_chan mc[MBOX_CNT];
65 struct mbox_chan chans[MBOX_CNT];
66 };
67
mb_chan_send_msg(struct slimpro_mbox_chan * mb_chan,u32 * msg)68 static void mb_chan_send_msg(struct slimpro_mbox_chan *mb_chan, u32 *msg)
69 {
70 writel(msg[1], mb_chan->reg + REG_DB_DOUT0);
71 writel(msg[2], mb_chan->reg + REG_DB_DOUT1);
72 writel(msg[0], mb_chan->reg + REG_DB_OUT);
73 }
74
mb_chan_recv_msg(struct slimpro_mbox_chan * mb_chan)75 static void mb_chan_recv_msg(struct slimpro_mbox_chan *mb_chan)
76 {
77 mb_chan->rx_msg[1] = readl(mb_chan->reg + REG_DB_DIN0);
78 mb_chan->rx_msg[2] = readl(mb_chan->reg + REG_DB_DIN1);
79 mb_chan->rx_msg[0] = readl(mb_chan->reg + REG_DB_IN);
80 }
81
mb_chan_status_ack(struct slimpro_mbox_chan * mb_chan)82 static int mb_chan_status_ack(struct slimpro_mbox_chan *mb_chan)
83 {
84 u32 val = readl(mb_chan->reg + REG_DB_STAT);
85
86 if (val & MBOX_STATUS_ACK_MASK) {
87 writel(MBOX_STATUS_ACK_MASK, mb_chan->reg + REG_DB_STAT);
88 return 1;
89 }
90 return 0;
91 }
92
mb_chan_status_avail(struct slimpro_mbox_chan * mb_chan)93 static int mb_chan_status_avail(struct slimpro_mbox_chan *mb_chan)
94 {
95 u32 val = readl(mb_chan->reg + REG_DB_STAT);
96
97 if (val & MBOX_STATUS_AVAIL_MASK) {
98 mb_chan_recv_msg(mb_chan);
99 writel(MBOX_STATUS_AVAIL_MASK, mb_chan->reg + REG_DB_STAT);
100 return 1;
101 }
102 return 0;
103 }
104
slimpro_mbox_irq(int irq,void * id)105 static irqreturn_t slimpro_mbox_irq(int irq, void *id)
106 {
107 struct slimpro_mbox_chan *mb_chan = id;
108
109 if (mb_chan_status_ack(mb_chan))
110 mbox_chan_txdone(mb_chan->chan, 0);
111
112 if (mb_chan_status_avail(mb_chan))
113 mbox_chan_received_data(mb_chan->chan, mb_chan->rx_msg);
114
115 return IRQ_HANDLED;
116 }
117
slimpro_mbox_send_data(struct mbox_chan * chan,void * msg)118 static int slimpro_mbox_send_data(struct mbox_chan *chan, void *msg)
119 {
120 struct slimpro_mbox_chan *mb_chan = chan->con_priv;
121
122 mb_chan_send_msg(mb_chan, msg);
123 return 0;
124 }
125
slimpro_mbox_startup(struct mbox_chan * chan)126 static int slimpro_mbox_startup(struct mbox_chan *chan)
127 {
128 struct slimpro_mbox_chan *mb_chan = chan->con_priv;
129 int rc;
130 u32 val;
131
132 rc = devm_request_irq(mb_chan->dev, mb_chan->irq, slimpro_mbox_irq, 0,
133 MBOX_CON_NAME, mb_chan);
134 if (unlikely(rc)) {
135 dev_err(mb_chan->dev, "failed to register mailbox interrupt %d\n",
136 mb_chan->irq);
137 return rc;
138 }
139
140 /* Enable HW interrupt */
141 writel(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK,
142 mb_chan->reg + REG_DB_STAT);
143 /* Unmask doorbell status interrupt */
144 val = readl(mb_chan->reg + REG_DB_STATMASK);
145 val &= ~(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
146 writel(val, mb_chan->reg + REG_DB_STATMASK);
147
148 return 0;
149 }
150
slimpro_mbox_shutdown(struct mbox_chan * chan)151 static void slimpro_mbox_shutdown(struct mbox_chan *chan)
152 {
153 struct slimpro_mbox_chan *mb_chan = chan->con_priv;
154 u32 val;
155
156 /* Mask doorbell status interrupt */
157 val = readl(mb_chan->reg + REG_DB_STATMASK);
158 val |= (MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
159 writel(val, mb_chan->reg + REG_DB_STATMASK);
160
161 devm_free_irq(mb_chan->dev, mb_chan->irq, mb_chan);
162 }
163
164 static const struct mbox_chan_ops slimpro_mbox_ops = {
165 .send_data = slimpro_mbox_send_data,
166 .startup = slimpro_mbox_startup,
167 .shutdown = slimpro_mbox_shutdown,
168 };
169
slimpro_mbox_probe(struct platform_device * pdev)170 static int slimpro_mbox_probe(struct platform_device *pdev)
171 {
172 struct slimpro_mbox *ctx;
173 void __iomem *mb_base;
174 int rc;
175 int i;
176
177 ctx = devm_kzalloc(&pdev->dev, sizeof(struct slimpro_mbox), GFP_KERNEL);
178 if (!ctx)
179 return -ENOMEM;
180
181 platform_set_drvdata(pdev, ctx);
182
183 mb_base = devm_platform_ioremap_resource(pdev, 0);
184 if (IS_ERR(mb_base))
185 return PTR_ERR(mb_base);
186
187 /* Setup mailbox links */
188 for (i = 0; i < MBOX_CNT; i++) {
189 ctx->mc[i].irq = platform_get_irq(pdev, i);
190 if (ctx->mc[i].irq < 0) {
191 if (i == 0) {
192 dev_err(&pdev->dev, "no available IRQ\n");
193 return -EINVAL;
194 }
195 dev_info(&pdev->dev, "no IRQ for channel %d\n", i);
196 break;
197 }
198
199 ctx->mc[i].dev = &pdev->dev;
200 ctx->mc[i].reg = mb_base + i * MBOX_REG_SET_OFFSET;
201 ctx->mc[i].chan = &ctx->chans[i];
202 ctx->chans[i].con_priv = &ctx->mc[i];
203 }
204
205 /* Setup mailbox controller */
206 ctx->mb_ctrl.dev = &pdev->dev;
207 ctx->mb_ctrl.chans = ctx->chans;
208 ctx->mb_ctrl.txdone_irq = true;
209 ctx->mb_ctrl.ops = &slimpro_mbox_ops;
210 ctx->mb_ctrl.num_chans = i;
211
212 rc = devm_mbox_controller_register(&pdev->dev, &ctx->mb_ctrl);
213 if (rc) {
214 dev_err(&pdev->dev,
215 "APM X-Gene SLIMpro MailBox register failed:%d\n", rc);
216 return rc;
217 }
218
219 dev_info(&pdev->dev, "APM X-Gene SLIMpro MailBox registered\n");
220 return 0;
221 }
222
223 static const struct of_device_id slimpro_of_match[] = {
224 {.compatible = "apm,xgene-slimpro-mbox" },
225 { },
226 };
227 MODULE_DEVICE_TABLE(of, slimpro_of_match);
228
229 #ifdef CONFIG_ACPI
230 static const struct acpi_device_id slimpro_acpi_ids[] = {
231 {"APMC0D01", 0},
232 {}
233 };
234 MODULE_DEVICE_TABLE(acpi, slimpro_acpi_ids);
235 #endif
236
237 static struct platform_driver slimpro_mbox_driver = {
238 .probe = slimpro_mbox_probe,
239 .driver = {
240 .name = "xgene-slimpro-mbox",
241 .of_match_table = of_match_ptr(slimpro_of_match),
242 .acpi_match_table = ACPI_PTR(slimpro_acpi_ids)
243 },
244 };
245
slimpro_mbox_init(void)246 static int __init slimpro_mbox_init(void)
247 {
248 return platform_driver_register(&slimpro_mbox_driver);
249 }
250
slimpro_mbox_exit(void)251 static void __exit slimpro_mbox_exit(void)
252 {
253 platform_driver_unregister(&slimpro_mbox_driver);
254 }
255
256 subsys_initcall(slimpro_mbox_init);
257 module_exit(slimpro_mbox_exit);
258
259 MODULE_DESCRIPTION("APM X-Gene SLIMpro Mailbox Driver");
260 MODULE_LICENSE("GPL");
261