summaryrefslogtreecommitdiff
path: root/drivers/mailbox/armada-37xx-rwtm-mailbox.c
blob: 456a117a65fdf3e6cb17279d831a0aa8fe719627 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
// SPDX-License-Identifier: GPL-2.0+
/*
 * rWTM BIU Mailbox driver for Armada 37xx
 *
 * Author: Marek Behún <kabel@kernel.org>
 */

#include <linux/device.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/mailbox_controller.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/armada-37xx-rwtm-mailbox.h>

#define DRIVER_NAME	"armada-37xx-rwtm-mailbox"

/* relative to rWTM BIU Mailbox Registers */
#define RWTM_MBOX_PARAM(i)		(0x0 + ((i) << 2))
#define RWTM_MBOX_COMMAND		0x40
#define RWTM_MBOX_RETURN_STATUS		0x80
#define RWTM_MBOX_STATUS(i)		(0x84 + ((i) << 2))
#define RWTM_MBOX_FIFO_STATUS		0xc4
#define FIFO_STS_RDY			0x100
#define FIFO_STS_CNTR_MASK		0x7
#define FIFO_STS_CNTR_MAX		4

#define RWTM_HOST_INT_RESET		0xc8
#define RWTM_HOST_INT_MASK		0xcc
#define SP_CMD_COMPLETE			BIT(0)
#define SP_CMD_QUEUE_FULL_ACCESS	BIT(17)
#define SP_CMD_QUEUE_FULL		BIT(18)

struct a37xx_mbox {
	struct device *dev;
	struct mbox_controller controller;
	void __iomem *base;
	int irq;
};

static void a37xx_mbox_receive(struct mbox_chan *chan)
{
	struct a37xx_mbox *mbox = chan->con_priv;
	struct armada_37xx_rwtm_rx_msg rx_msg;
	int i;

	rx_msg.retval = readl(mbox->base + RWTM_MBOX_RETURN_STATUS);
	for (i = 0; i < 16; ++i)
		rx_msg.status[i] = readl(mbox->base + RWTM_MBOX_STATUS(i));

	mbox_chan_received_data(chan, &rx_msg);
}

static irqreturn_t a37xx_mbox_irq_handler(int irq, void *data)
{
	struct mbox_chan *chan = data;
	struct a37xx_mbox *mbox = chan->con_priv;
	u32 reg;

	reg = readl(mbox->base + RWTM_HOST_INT_RESET);

	if (reg & SP_CMD_COMPLETE)
		a37xx_mbox_receive(chan);

	if (reg & (SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL))
		dev_err(mbox->dev, "Secure processor command queue full\n");

	writel(reg, mbox->base + RWTM_HOST_INT_RESET);
	if (reg)
		mbox_chan_txdone(chan, 0);

	return reg ? IRQ_HANDLED : IRQ_NONE;
}

static int a37xx_mbox_send_data(struct mbox_chan *chan, void *data)
{
	struct a37xx_mbox *mbox = chan->con_priv;
	struct armada_37xx_rwtm_tx_msg *msg = data;
	int i;
	u32 reg;

	if (!data)
		return -EINVAL;

	reg = readl(mbox->base + RWTM_MBOX_FIFO_STATUS);
	if (!(reg & FIFO_STS_RDY))
		dev_warn(mbox->dev, "Secure processor not ready\n");

	if ((reg & FIFO_STS_CNTR_MASK) >= FIFO_STS_CNTR_MAX) {
		dev_err(mbox->dev, "Secure processor command queue full\n");
		return -EBUSY;
	}

	for (i = 0; i < 16; ++i)
		writel(msg->args[i], mbox->base + RWTM_MBOX_PARAM(i));
	writel(msg->command, mbox->base + RWTM_MBOX_COMMAND);

	return 0;
}

static int a37xx_mbox_startup(struct mbox_chan *chan)
{
	struct a37xx_mbox *mbox = chan->con_priv;
	u32 reg;
	int ret;

	ret = devm_request_irq(mbox->dev, mbox->irq, a37xx_mbox_irq_handler, 0,
			       DRIVER_NAME, chan);
	if (ret < 0) {
		dev_err(mbox->dev, "Cannot request irq\n");
		return ret;
	}

	/* enable IRQ generation */
	reg = readl(mbox->base + RWTM_HOST_INT_MASK);
	reg &= ~(SP_CMD_COMPLETE | SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL);
	writel(reg, mbox->base + RWTM_HOST_INT_MASK);

	return 0;
}

static void a37xx_mbox_shutdown(struct mbox_chan *chan)
{
	u32 reg;
	struct a37xx_mbox *mbox = chan->con_priv;

	/* disable interrupt generation */
	reg = readl(mbox->base + RWTM_HOST_INT_MASK);
	reg |= SP_CMD_COMPLETE | SP_CMD_QUEUE_FULL_ACCESS | SP_CMD_QUEUE_FULL;
	writel(reg, mbox->base + RWTM_HOST_INT_MASK);

	devm_free_irq(mbox->dev, mbox->irq, chan);
}

static const struct mbox_chan_ops a37xx_mbox_ops = {
	.send_data	= a37xx_mbox_send_data,
	.startup	= a37xx_mbox_startup,
	.shutdown	= a37xx_mbox_shutdown,
};

static int armada_37xx_mbox_probe(struct platform_device *pdev)
{
	struct a37xx_mbox *mbox;
	struct mbox_chan *chans;
	int ret;

	mbox = devm_kzalloc(&pdev->dev, sizeof(*mbox), GFP_KERNEL);
	if (!mbox)
		return -ENOMEM;

	/* Allocated one channel */
	chans = devm_kzalloc(&pdev->dev, sizeof(*chans), GFP_KERNEL);
	if (!chans)
		return -ENOMEM;

	mbox->base = devm_platform_ioremap_resource(pdev, 0);
	if (IS_ERR(mbox->base))
		return PTR_ERR(mbox->base);

	mbox->irq = platform_get_irq(pdev, 0);
	if (mbox->irq < 0)
		return mbox->irq;

	mbox->dev = &pdev->dev;

	/* Hardware supports only one channel. */
	chans[0].con_priv = mbox;
	mbox->controller.dev = mbox->dev;
	mbox->controller.num_chans = 1;
	mbox->controller.chans = chans;
	mbox->controller.ops = &a37xx_mbox_ops;
	mbox->controller.txdone_irq = true;

	ret = devm_mbox_controller_register(mbox->dev, &mbox->controller);
	if (ret) {
		dev_err(&pdev->dev, "Could not register mailbox controller\n");
		return ret;
	}

	platform_set_drvdata(pdev, mbox);
	return ret;
}


static const struct of_device_id armada_37xx_mbox_match[] = {
	{ .compatible = "marvell,armada-3700-rwtm-mailbox" },
	{ },
};

MODULE_DEVICE_TABLE(of, armada_37xx_mbox_match);

static struct platform_driver armada_37xx_mbox_driver = {
	.probe	= armada_37xx_mbox_probe,
	.driver	= {
		.name		= DRIVER_NAME,
		.of_match_table	= armada_37xx_mbox_match,
	},
};

module_platform_driver(armada_37xx_mbox_driver);

MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("rWTM BIU Mailbox driver for Armada 37xx");
MODULE_AUTHOR("Marek Behun <kabel@kernel.org>");