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Duc Dangf700e842016-02-12 19:39:26 -08001/*
2 * APM X-Gene SLIMpro MailBox Driver
3 *
4 * Copyright (c) 2015, Applied Micro Circuits Corporation
5 * Author: Feng Kan fkan@apm.com
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License as
9 * published by the Free Software Foundation; either version 2 of
10 * the License, or (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, see <http://www.gnu.org/licenses/>.
19 *
20 */
21#include <linux/acpi.h>
22#include <linux/delay.h>
23#include <linux/interrupt.h>
24#include <linux/io.h>
25#include <linux/mailbox_controller.h>
26#include <linux/module.h>
27#include <linux/of.h>
28#include <linux/platform_device.h>
29#include <linux/spinlock.h>
30
31#define MBOX_CON_NAME "slimpro-mbox"
32#define MBOX_REG_SET_OFFSET 0x1000
33#define MBOX_CNT 8
34#define MBOX_STATUS_AVAIL_MASK BIT(16)
35#define MBOX_STATUS_ACK_MASK BIT(0)
36
37/* Configuration and Status Registers */
38#define REG_DB_IN 0x00
39#define REG_DB_DIN0 0x04
40#define REG_DB_DIN1 0x08
41#define REG_DB_OUT 0x10
42#define REG_DB_DOUT0 0x14
43#define REG_DB_DOUT1 0x18
44#define REG_DB_STAT 0x20
45#define REG_DB_STATMASK 0x24
46
47/**
48 * X-Gene SlimPRO mailbox channel information
49 *
50 * @dev: Device to which it is attached
51 * @chan: Pointer to mailbox communication channel
52 * @reg: Base address to access channel registers
53 * @irq: Interrupt number of the channel
54 * @rx_msg: Received message storage
55 */
56struct slimpro_mbox_chan {
57 struct device *dev;
58 struct mbox_chan *chan;
59 void __iomem *reg;
60 int irq;
61 u32 rx_msg[3];
62};
63
64/**
65 * X-Gene SlimPRO Mailbox controller data
66 *
67 * X-Gene SlimPRO Mailbox controller has 8 commnunication channels.
68 * Each channel has a separate IRQ number assgined to it.
69 *
70 * @mb_ctrl: Representation of the commnunication channel controller
71 * @mc: Array of SlimPRO mailbox channels of the controller
72 * @chans: Array of mailbox communication channels
73 *
74 */
75struct slimpro_mbox {
76 struct mbox_controller mb_ctrl;
77 struct slimpro_mbox_chan mc[MBOX_CNT];
78 struct mbox_chan chans[MBOX_CNT];
79};
80
81static void mb_chan_send_msg(struct slimpro_mbox_chan *mb_chan, u32 *msg)
82{
83 writel(msg[1], mb_chan->reg + REG_DB_DOUT0);
84 writel(msg[2], mb_chan->reg + REG_DB_DOUT1);
85 writel(msg[0], mb_chan->reg + REG_DB_OUT);
86}
87
88static void mb_chan_recv_msg(struct slimpro_mbox_chan *mb_chan)
89{
90 mb_chan->rx_msg[1] = readl(mb_chan->reg + REG_DB_DIN0);
91 mb_chan->rx_msg[2] = readl(mb_chan->reg + REG_DB_DIN1);
92 mb_chan->rx_msg[0] = readl(mb_chan->reg + REG_DB_IN);
93}
94
95static int mb_chan_status_ack(struct slimpro_mbox_chan *mb_chan)
96{
97 u32 val = readl(mb_chan->reg + REG_DB_STAT);
98
99 if (val & MBOX_STATUS_ACK_MASK) {
100 writel(MBOX_STATUS_ACK_MASK, mb_chan->reg + REG_DB_STAT);
101 return 1;
102 }
103 return 0;
104}
105
106static int mb_chan_status_avail(struct slimpro_mbox_chan *mb_chan)
107{
108 u32 val = readl(mb_chan->reg + REG_DB_STAT);
109
110 if (val & MBOX_STATUS_AVAIL_MASK) {
111 mb_chan_recv_msg(mb_chan);
112 writel(MBOX_STATUS_AVAIL_MASK, mb_chan->reg + REG_DB_STAT);
113 return 1;
114 }
115 return 0;
116}
117
118static irqreturn_t slimpro_mbox_irq(int irq, void *id)
119{
120 struct slimpro_mbox_chan *mb_chan = id;
121
122 if (mb_chan_status_ack(mb_chan))
123 mbox_chan_txdone(mb_chan->chan, 0);
124
125 if (mb_chan_status_avail(mb_chan))
126 mbox_chan_received_data(mb_chan->chan, mb_chan->rx_msg);
127
128 return IRQ_HANDLED;
129}
130
131static int slimpro_mbox_send_data(struct mbox_chan *chan, void *msg)
132{
133 struct slimpro_mbox_chan *mb_chan = chan->con_priv;
134
135 mb_chan_send_msg(mb_chan, msg);
136 return 0;
137}
138
139static int slimpro_mbox_startup(struct mbox_chan *chan)
140{
141 struct slimpro_mbox_chan *mb_chan = chan->con_priv;
142 int rc;
143 u32 val;
144
145 rc = devm_request_irq(mb_chan->dev, mb_chan->irq, slimpro_mbox_irq, 0,
146 MBOX_CON_NAME, mb_chan);
147 if (unlikely(rc)) {
148 dev_err(mb_chan->dev, "failed to register mailbox interrupt %d\n",
149 mb_chan->irq);
150 return rc;
151 }
152
153 /* Enable HW interrupt */
154 writel(MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK,
155 mb_chan->reg + REG_DB_STAT);
156 /* Unmask 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 return 0;
162}
163
164static void slimpro_mbox_shutdown(struct mbox_chan *chan)
165{
166 struct slimpro_mbox_chan *mb_chan = chan->con_priv;
167 u32 val;
168
169 /* Mask doorbell status interrupt */
170 val = readl(mb_chan->reg + REG_DB_STATMASK);
171 val |= (MBOX_STATUS_ACK_MASK | MBOX_STATUS_AVAIL_MASK);
172 writel(val, mb_chan->reg + REG_DB_STATMASK);
173
174 devm_free_irq(mb_chan->dev, mb_chan->irq, mb_chan);
175}
176
177static struct mbox_chan_ops slimpro_mbox_ops = {
178 .send_data = slimpro_mbox_send_data,
179 .startup = slimpro_mbox_startup,
180 .shutdown = slimpro_mbox_shutdown,
181};
182
183static int slimpro_mbox_probe(struct platform_device *pdev)
184{
185 struct slimpro_mbox *ctx;
186 struct resource *regs;
187 void __iomem *mb_base;
188 int rc;
189 int i;
190
191 ctx = devm_kzalloc(&pdev->dev, sizeof(struct slimpro_mbox), GFP_KERNEL);
Axel Lina61b37e2016-03-21 20:12:20 +0800192 if (!ctx)
193 return -ENOMEM;
Duc Dangf700e842016-02-12 19:39:26 -0800194
195 platform_set_drvdata(pdev, ctx);
196
197 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
198 mb_base = devm_ioremap(&pdev->dev, regs->start, resource_size(regs));
Dan Carpenter14d653a2016-02-26 00:32:21 +0300199 if (!mb_base)
200 return -ENOMEM;
Duc Dangf700e842016-02-12 19:39:26 -0800201
202 /* Setup mailbox links */
203 for (i = 0; i < MBOX_CNT; i++) {
204 ctx->mc[i].irq = platform_get_irq(pdev, i);
205 if (ctx->mc[i].irq < 0) {
206 if (i == 0) {
207 dev_err(&pdev->dev, "no available IRQ\n");
208 return -EINVAL;
209 }
210 dev_info(&pdev->dev, "no IRQ for channel %d\n", i);
211 break;
212 }
213
214 ctx->mc[i].dev = &pdev->dev;
215 ctx->mc[i].reg = mb_base + i * MBOX_REG_SET_OFFSET;
216 ctx->mc[i].chan = &ctx->chans[i];
217 ctx->chans[i].con_priv = &ctx->mc[i];
218 }
219
220 /* Setup mailbox controller */
221 ctx->mb_ctrl.dev = &pdev->dev;
222 ctx->mb_ctrl.chans = ctx->chans;
223 ctx->mb_ctrl.txdone_irq = true;
224 ctx->mb_ctrl.ops = &slimpro_mbox_ops;
225 ctx->mb_ctrl.num_chans = i;
226
227 rc = mbox_controller_register(&ctx->mb_ctrl);
228 if (rc) {
229 dev_err(&pdev->dev,
230 "APM X-Gene SLIMpro MailBox register failed:%d\n", rc);
231 return rc;
232 }
233
234 dev_info(&pdev->dev, "APM X-Gene SLIMpro MailBox registered\n");
235 return 0;
236}
237
238static int slimpro_mbox_remove(struct platform_device *pdev)
239{
240 struct slimpro_mbox *smb = platform_get_drvdata(pdev);
241
242 mbox_controller_unregister(&smb->mb_ctrl);
243 return 0;
244}
245
246static const struct of_device_id slimpro_of_match[] = {
247 {.compatible = "apm,xgene-slimpro-mbox" },
248 { },
249};
250MODULE_DEVICE_TABLE(of, slimpro_of_match);
251
252#ifdef CONFIG_ACPI
253static const struct acpi_device_id slimpro_acpi_ids[] = {
254 {"APMC0D01", 0},
255 {}
256};
257MODULE_DEVICE_TABLE(acpi, slimpro_acpi_ids);
258#endif
259
260static struct platform_driver slimpro_mbox_driver = {
261 .probe = slimpro_mbox_probe,
262 .remove = slimpro_mbox_remove,
263 .driver = {
264 .name = "xgene-slimpro-mbox",
265 .of_match_table = of_match_ptr(slimpro_of_match),
266 .acpi_match_table = ACPI_PTR(slimpro_acpi_ids)
267 },
268};
269
270static int __init slimpro_mbox_init(void)
271{
272 return platform_driver_register(&slimpro_mbox_driver);
273}
274
275static void __exit slimpro_mbox_exit(void)
276{
277 platform_driver_unregister(&slimpro_mbox_driver);
278}
279
280subsys_initcall(slimpro_mbox_init);
281module_exit(slimpro_mbox_exit);
282
283MODULE_DESCRIPTION("APM X-Gene SLIMpro Mailbox Driver");
284MODULE_LICENSE("GPL");