1 /*
2 * Copyright 2012 Calxeda, Inc.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License along with
14 * this program. If not, see <http://www.gnu.org/licenses/>.
15 */
16 #include <linux/types.h>
17 #include <linux/err.h>
18 #include <linux/delay.h>
19 #include <linux/export.h>
20 #include <linux/io.h>
21 #include <linux/interrupt.h>
22 #include <linux/completion.h>
23 #include <linux/mutex.h>
24 #include <linux/notifier.h>
25 #include <linux/spinlock.h>
26 #include <linux/device.h>
27 #include <linux/amba/bus.h>
28
29 #include <linux/pl320-ipc.h>
30
31 #define IPCMxSOURCE(m) ((m) * 0x40)
32 #define IPCMxDSET(m) (((m) * 0x40) + 0x004)
33 #define IPCMxDCLEAR(m) (((m) * 0x40) + 0x008)
34 #define IPCMxDSTATUS(m) (((m) * 0x40) + 0x00C)
35 #define IPCMxMODE(m) (((m) * 0x40) + 0x010)
36 #define IPCMxMSET(m) (((m) * 0x40) + 0x014)
37 #define IPCMxMCLEAR(m) (((m) * 0x40) + 0x018)
38 #define IPCMxMSTATUS(m) (((m) * 0x40) + 0x01C)
39 #define IPCMxSEND(m) (((m) * 0x40) + 0x020)
40 #define IPCMxDR(m, dr) (((m) * 0x40) + ((dr) * 4) + 0x024)
41
42 #define IPCMMIS(irq) (((irq) * 8) + 0x800)
43 #define IPCMRIS(irq) (((irq) * 8) + 0x804)
44
45 #define MBOX_MASK(n) (1 << (n))
46 #define IPC_TX_MBOX 1
47 #define IPC_RX_MBOX 2
48
49 #define CHAN_MASK(n) (1 << (n))
50 #define A9_SOURCE 1
51 #define M3_SOURCE 0
52
53 static void __iomem *ipc_base;
54 static int ipc_irq;
55 static DEFINE_MUTEX(ipc_m1_lock);
56 static DECLARE_COMPLETION(ipc_completion);
57 static ATOMIC_NOTIFIER_HEAD(ipc_notifier);
58
set_destination(int source,int mbox)59 static inline void set_destination(int source, int mbox)
60 {
61 __raw_writel(CHAN_MASK(source), ipc_base + IPCMxDSET(mbox));
62 __raw_writel(CHAN_MASK(source), ipc_base + IPCMxMSET(mbox));
63 }
64
clear_destination(int source,int mbox)65 static inline void clear_destination(int source, int mbox)
66 {
67 __raw_writel(CHAN_MASK(source), ipc_base + IPCMxDCLEAR(mbox));
68 __raw_writel(CHAN_MASK(source), ipc_base + IPCMxMCLEAR(mbox));
69 }
70
__ipc_send(int mbox,u32 * data)71 static void __ipc_send(int mbox, u32 *data)
72 {
73 int i;
74 for (i = 0; i < 7; i++)
75 __raw_writel(data[i], ipc_base + IPCMxDR(mbox, i));
76 __raw_writel(0x1, ipc_base + IPCMxSEND(mbox));
77 }
78
__ipc_rcv(int mbox,u32 * data)79 static u32 __ipc_rcv(int mbox, u32 *data)
80 {
81 int i;
82 for (i = 0; i < 7; i++)
83 data[i] = __raw_readl(ipc_base + IPCMxDR(mbox, i));
84 return data[1];
85 }
86
87 /* blocking implmentation from the A9 side, not usuable in interrupts! */
pl320_ipc_transmit(u32 * data)88 int pl320_ipc_transmit(u32 *data)
89 {
90 int ret;
91
92 mutex_lock(&ipc_m1_lock);
93
94 init_completion(&ipc_completion);
95 __ipc_send(IPC_TX_MBOX, data);
96 ret = wait_for_completion_timeout(&ipc_completion,
97 msecs_to_jiffies(1000));
98 if (ret == 0) {
99 ret = -ETIMEDOUT;
100 goto out;
101 }
102
103 ret = __ipc_rcv(IPC_TX_MBOX, data);
104 out:
105 mutex_unlock(&ipc_m1_lock);
106 return ret;
107 }
108 EXPORT_SYMBOL_GPL(pl320_ipc_transmit);
109
ipc_handler(int irq,void * dev)110 static irqreturn_t ipc_handler(int irq, void *dev)
111 {
112 u32 irq_stat;
113 u32 data[7];
114
115 irq_stat = __raw_readl(ipc_base + IPCMMIS(1));
116 if (irq_stat & MBOX_MASK(IPC_TX_MBOX)) {
117 __raw_writel(0, ipc_base + IPCMxSEND(IPC_TX_MBOX));
118 complete(&ipc_completion);
119 }
120 if (irq_stat & MBOX_MASK(IPC_RX_MBOX)) {
121 __ipc_rcv(IPC_RX_MBOX, data);
122 atomic_notifier_call_chain(&ipc_notifier, data[0], data + 1);
123 __raw_writel(2, ipc_base + IPCMxSEND(IPC_RX_MBOX));
124 }
125
126 return IRQ_HANDLED;
127 }
128
pl320_ipc_register_notifier(struct notifier_block * nb)129 int pl320_ipc_register_notifier(struct notifier_block *nb)
130 {
131 return atomic_notifier_chain_register(&ipc_notifier, nb);
132 }
133 EXPORT_SYMBOL_GPL(pl320_ipc_register_notifier);
134
pl320_ipc_unregister_notifier(struct notifier_block * nb)135 int pl320_ipc_unregister_notifier(struct notifier_block *nb)
136 {
137 return atomic_notifier_chain_unregister(&ipc_notifier, nb);
138 }
139 EXPORT_SYMBOL_GPL(pl320_ipc_unregister_notifier);
140
pl320_probe(struct amba_device * adev,const struct amba_id * id)141 static int pl320_probe(struct amba_device *adev, const struct amba_id *id)
142 {
143 int ret;
144
145 ipc_base = ioremap(adev->res.start, resource_size(&adev->res));
146 if (ipc_base == NULL)
147 return -ENOMEM;
148
149 __raw_writel(0, ipc_base + IPCMxSEND(IPC_TX_MBOX));
150
151 ipc_irq = adev->irq[0];
152 ret = request_irq(ipc_irq, ipc_handler, 0, dev_name(&adev->dev), NULL);
153 if (ret < 0)
154 goto err;
155
156 /* Init slow mailbox */
157 __raw_writel(CHAN_MASK(A9_SOURCE),
158 ipc_base + IPCMxSOURCE(IPC_TX_MBOX));
159 __raw_writel(CHAN_MASK(M3_SOURCE),
160 ipc_base + IPCMxDSET(IPC_TX_MBOX));
161 __raw_writel(CHAN_MASK(M3_SOURCE) | CHAN_MASK(A9_SOURCE),
162 ipc_base + IPCMxMSET(IPC_TX_MBOX));
163
164 /* Init receive mailbox */
165 __raw_writel(CHAN_MASK(M3_SOURCE),
166 ipc_base + IPCMxSOURCE(IPC_RX_MBOX));
167 __raw_writel(CHAN_MASK(A9_SOURCE),
168 ipc_base + IPCMxDSET(IPC_RX_MBOX));
169 __raw_writel(CHAN_MASK(M3_SOURCE) | CHAN_MASK(A9_SOURCE),
170 ipc_base + IPCMxMSET(IPC_RX_MBOX));
171
172 return 0;
173 err:
174 iounmap(ipc_base);
175 return ret;
176 }
177
178 static struct amba_id pl320_ids[] = {
179 {
180 .id = 0x00041320,
181 .mask = 0x000fffff,
182 },
183 { 0, 0 },
184 };
185
186 static struct amba_driver pl320_driver = {
187 .drv = {
188 .name = "pl320",
189 },
190 .id_table = pl320_ids,
191 .probe = pl320_probe,
192 };
193
ipc_init(void)194 static int __init ipc_init(void)
195 {
196 return amba_driver_register(&pl320_driver);
197 }
198 module_init(ipc_init);
199