1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * rWTM BIU Mailbox driver for Armada 37xx
4 *
5 * Author: Marek Behún <kabel@kernel.org>
6 */
7
8#include <linux/device.h>
9#include <linux/interrupt.h>
10#include <linux/io.h>
11#include <linux/kernel.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/armada-37xx-rwtm-mailbox.h>
17
18#define DRIVER_NAME "armada-37xx-rwtm-mailbox"
19
20/* relative to rWTM BIU Mailbox Registers */
21#define RWTM_MBOX_PARAM(i) (0x0 + ((i) << 2))
22#define RWTM_MBOX_COMMAND 0x40
23#define RWTM_MBOX_RETURN_STATUS 0x80
24#define RWTM_MBOX_STATUS(i) (0x84 + ((i) << 2))
25#define RWTM_MBOX_FIFO_STATUS 0xc4
26#define FIFO_STS_RDY 0x100
27#define FIFO_STS_CNTR_MASK 0x7
28#define FIFO_STS_CNTR_MAX 4
29
30#define RWTM_HOST_INT_RESET 0xc8
31#define RWTM_HOST_INT_MASK 0xcc
32#define SP_CMD_COMPLETE BIT(0)
33#define SP_CMD_QUEUE_FULL_ACCESS BIT(17)
34#define SP_CMD_QUEUE_FULL BIT(18)
35
36struct a37xx_mbox {
37 struct device *dev;
38 struct mbox_controller controller;
39 void __iomem *base;
40 int irq;
41};
42
43static void a37xx_mbox_receive(struct mbox_chan *chan)
44{
45 struct a37xx_mbox *mbox = chan->con_priv;
46 struct armada_37xx_rwtm_rx_msg rx_msg;
47 int i;
48
49 rx_msg.retval = readl(addr: mbox->base + RWTM_MBOX_RETURN_STATUS);
50 for (i = 0; i < 16; ++i)
51 rx_msg.status[i] = readl(addr: mbox->base + RWTM_MBOX_STATUS(i));
52
53 mbox_chan_received_data(chan, data: &rx_msg);
54}
55
56static irqreturn_t a37xx_mbox_irq_handler(int irq, void *data)
57{
58 struct mbox_chan *chan = data;
59 struct a37xx_mbox *mbox = chan->con_priv;
60 u32 reg;
61
62 reg = readl(addr: mbox->base + RWTM_HOST_INT_RESET);
63
64 if (reg & SP_CMD_COMPLETE)
65 a37xx_mbox_receive(chan);
66
67 if (reg & (SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL))
68 dev_err(mbox->dev, "Secure processor command queue full\n");
69
70 writel(val: reg, addr: mbox->base + RWTM_HOST_INT_RESET);
71 if (reg)
72 mbox_chan_txdone(chan, r: 0);
73
74 return reg ? IRQ_HANDLED : IRQ_NONE;
75}
76
77static int a37xx_mbox_send_data(struct mbox_chan *chan, void *data)
78{
79 struct a37xx_mbox *mbox = chan->con_priv;
80 struct armada_37xx_rwtm_tx_msg *msg = data;
81 int i;
82 u32 reg;
83
84 if (!data)
85 return -EINVAL;
86
87 reg = readl(addr: mbox->base + RWTM_MBOX_FIFO_STATUS);
88 if (!(reg & FIFO_STS_RDY))
89 dev_warn(mbox->dev, "Secure processor not ready\n");
90
91 if ((reg & FIFO_STS_CNTR_MASK) >= FIFO_STS_CNTR_MAX) {
92 dev_err(mbox->dev, "Secure processor command queue full\n");
93 return -EBUSY;
94 }
95
96 for (i = 0; i < 16; ++i)
97 writel(val: msg->args[i], addr: mbox->base + RWTM_MBOX_PARAM(i));
98 writel(val: msg->command, addr: mbox->base + RWTM_MBOX_COMMAND);
99
100 return 0;
101}
102
103static int a37xx_mbox_startup(struct mbox_chan *chan)
104{
105 struct a37xx_mbox *mbox = chan->con_priv;
106 u32 reg;
107 int ret;
108
109 ret = devm_request_irq(dev: mbox->dev, irq: mbox->irq, handler: a37xx_mbox_irq_handler, irqflags: 0,
110 DRIVER_NAME, dev_id: chan);
111 if (ret < 0) {
112 dev_err(mbox->dev, "Cannot request irq\n");
113 return ret;
114 }
115
116 /* enable IRQ generation */
117 reg = readl(addr: mbox->base + RWTM_HOST_INT_MASK);
118 reg &= ~(SP_CMD_COMPLETE | SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL);
119 writel(val: reg, addr: mbox->base + RWTM_HOST_INT_MASK);
120
121 return 0;
122}
123
124static void a37xx_mbox_shutdown(struct mbox_chan *chan)
125{
126 u32 reg;
127 struct a37xx_mbox *mbox = chan->con_priv;
128
129 /* disable interrupt generation */
130 reg = readl(addr: mbox->base + RWTM_HOST_INT_MASK);
131 reg |= SP_CMD_COMPLETE | SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL;
132 writel(val: reg, addr: mbox->base + RWTM_HOST_INT_MASK);
133
134 devm_free_irq(dev: mbox->dev, irq: mbox->irq, dev_id: chan);
135}
136
137static const struct mbox_chan_ops a37xx_mbox_ops = {
138 .send_data = a37xx_mbox_send_data,
139 .startup = a37xx_mbox_startup,
140 .shutdown = a37xx_mbox_shutdown,
141};
142
143static int armada_37xx_mbox_probe(struct platform_device *pdev)
144{
145 struct a37xx_mbox *mbox;
146 struct mbox_chan *chans;
147 int ret;
148
149 mbox = devm_kzalloc(dev: &pdev->dev, size: sizeof(*mbox), GFP_KERNEL);
150 if (!mbox)
151 return -ENOMEM;
152
153 /* Allocated one channel */
154 chans = devm_kzalloc(dev: &pdev->dev, size: sizeof(*chans), GFP_KERNEL);
155 if (!chans)
156 return -ENOMEM;
157
158 mbox->base = devm_platform_ioremap_resource(pdev, index: 0);
159 if (IS_ERR(ptr: mbox->base))
160 return PTR_ERR(ptr: mbox->base);
161
162 mbox->irq = platform_get_irq(pdev, 0);
163 if (mbox->irq < 0)
164 return mbox->irq;
165
166 mbox->dev = &pdev->dev;
167
168 /* Hardware supports only one channel. */
169 chans[0].con_priv = mbox;
170 mbox->controller.dev = mbox->dev;
171 mbox->controller.num_chans = 1;
172 mbox->controller.chans = chans;
173 mbox->controller.ops = &a37xx_mbox_ops;
174 mbox->controller.txdone_irq = true;
175
176 ret = devm_mbox_controller_register(dev: mbox->dev, mbox: &mbox->controller);
177 if (ret) {
178 dev_err(&pdev->dev, "Could not register mailbox controller\n");
179 return ret;
180 }
181
182 platform_set_drvdata(pdev, data: mbox);
183 return ret;
184}
185
186
187static const struct of_device_id armada_37xx_mbox_match[] = {
188 { .compatible = "marvell,armada-3700-rwtm-mailbox" },
189 { },
190};
191
192MODULE_DEVICE_TABLE(of, armada_37xx_mbox_match);
193
194static struct platform_driver armada_37xx_mbox_driver = {
195 .probe = armada_37xx_mbox_probe,
196 .driver = {
197 .name = DRIVER_NAME,
198 .of_match_table = armada_37xx_mbox_match,
199 },
200};
201
202module_platform_driver(armada_37xx_mbox_driver);
203
204MODULE_LICENSE("GPL v2");
205MODULE_DESCRIPTION("rWTM BIU Mailbox driver for Armada 37xx");
206MODULE_AUTHOR("Marek Behun <kabel@kernel.org>");
207

source code of linux/drivers/mailbox/armada-37xx-rwtm-mailbox.c