1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (c) 2018, NVIDIA CORPORATION.
4  */
5 
6 #include <linux/interrupt.h>
7 #include <linux/irq.h>
8 #include <linux/io.h>
9 #include <linux/of.h>
10 #include <linux/platform_device.h>
11 
12 #include <soc/tegra/bpmp.h>
13 
14 #include "bpmp-private.h"
15 
16 #define TRIGGER_OFFSET		0x000
17 #define RESULT_OFFSET(id)	(0xc00 + id * 4)
18 #define TRIGGER_ID_SHIFT	16
19 #define TRIGGER_CMD_GET		4
20 
21 #define STA_OFFSET		0
22 #define SET_OFFSET		4
23 #define CLR_OFFSET		8
24 
25 #define CH_MASK(ch)	(0x3 << ((ch) * 2))
26 #define SL_SIGL(ch)	(0x0 << ((ch) * 2))
27 #define SL_QUED(ch)	(0x1 << ((ch) * 2))
28 #define MA_FREE(ch)	(0x2 << ((ch) * 2))
29 #define MA_ACKD(ch)	(0x3 << ((ch) * 2))
30 
31 struct tegra210_bpmp {
32 	void __iomem *atomics;
33 	void __iomem *arb_sema;
34 	struct irq_data *tx_irq_data;
35 };
36 
37 static u32 bpmp_channel_status(struct tegra_bpmp *bpmp, unsigned int index)
38 {
39 	struct tegra210_bpmp *priv = bpmp->priv;
40 
41 	return __raw_readl(priv->arb_sema + STA_OFFSET) & CH_MASK(index);
42 }
43 
44 static bool tegra210_bpmp_is_response_ready(struct tegra_bpmp_channel *channel)
45 {
46 	unsigned int index = channel->index;
47 
48 	return bpmp_channel_status(channel->bpmp, index) == MA_ACKD(index);
49 }
50 
51 static bool tegra210_bpmp_is_request_ready(struct tegra_bpmp_channel *channel)
52 {
53 	unsigned int index = channel->index;
54 
55 	return bpmp_channel_status(channel->bpmp, index) == SL_SIGL(index);
56 }
57 
58 static bool
59 tegra210_bpmp_is_request_channel_free(struct tegra_bpmp_channel *channel)
60 {
61 	unsigned int index = channel->index;
62 
63 	return bpmp_channel_status(channel->bpmp, index) == MA_FREE(index);
64 }
65 
66 static bool
67 tegra210_bpmp_is_response_channel_free(struct tegra_bpmp_channel *channel)
68 {
69 	unsigned int index = channel->index;
70 
71 	return bpmp_channel_status(channel->bpmp, index) == SL_QUED(index);
72 }
73 
74 static int tegra210_bpmp_post_request(struct tegra_bpmp_channel *channel)
75 {
76 	struct tegra210_bpmp *priv = channel->bpmp->priv;
77 
78 	__raw_writel(CH_MASK(channel->index), priv->arb_sema + CLR_OFFSET);
79 
80 	return 0;
81 }
82 
83 static int tegra210_bpmp_post_response(struct tegra_bpmp_channel *channel)
84 {
85 	struct tegra210_bpmp *priv = channel->bpmp->priv;
86 
87 	__raw_writel(MA_ACKD(channel->index), priv->arb_sema + SET_OFFSET);
88 
89 	return 0;
90 }
91 
92 static int tegra210_bpmp_ack_response(struct tegra_bpmp_channel *channel)
93 {
94 	struct tegra210_bpmp *priv = channel->bpmp->priv;
95 
96 	__raw_writel(MA_ACKD(channel->index) ^ MA_FREE(channel->index),
97 		     priv->arb_sema + CLR_OFFSET);
98 
99 	return 0;
100 }
101 
102 static int tegra210_bpmp_ack_request(struct tegra_bpmp_channel *channel)
103 {
104 	struct tegra210_bpmp *priv = channel->bpmp->priv;
105 
106 	__raw_writel(SL_QUED(channel->index), priv->arb_sema + SET_OFFSET);
107 
108 	return 0;
109 }
110 
111 static int tegra210_bpmp_ring_doorbell(struct tegra_bpmp *bpmp)
112 {
113 	struct tegra210_bpmp *priv = bpmp->priv;
114 	struct irq_data *irq_data = priv->tx_irq_data;
115 
116 	/*
117 	 * Tegra Legacy Interrupt Controller (LIC) is used to notify BPMP of
118 	 * available messages
119 	 */
120 	if (irq_data->chip->irq_retrigger)
121 		return irq_data->chip->irq_retrigger(irq_data);
122 
123 	return -EINVAL;
124 }
125 
126 static irqreturn_t rx_irq(int irq, void *data)
127 {
128 	struct tegra_bpmp *bpmp = data;
129 
130 	tegra_bpmp_handle_rx(bpmp);
131 
132 	return IRQ_HANDLED;
133 }
134 
135 static int tegra210_bpmp_channel_init(struct tegra_bpmp_channel *channel,
136 				      struct tegra_bpmp *bpmp,
137 				      unsigned int index)
138 {
139 	struct tegra210_bpmp *priv = bpmp->priv;
140 	void __iomem *p;
141 	u32 address;
142 
143 	/* Retrieve channel base address from BPMP */
144 	writel(index << TRIGGER_ID_SHIFT | TRIGGER_CMD_GET,
145 	       priv->atomics + TRIGGER_OFFSET);
146 	address = readl(priv->atomics + RESULT_OFFSET(index));
147 
148 	p = devm_ioremap(bpmp->dev, address, 0x80);
149 	if (!p)
150 		return -ENOMEM;
151 
152 	iosys_map_set_vaddr_iomem(&channel->ib, p);
153 	iosys_map_set_vaddr_iomem(&channel->ob, p);
154 
155 	channel->index = index;
156 	init_completion(&channel->completion);
157 	channel->bpmp = bpmp;
158 
159 	return 0;
160 }
161 
162 static int tegra210_bpmp_init(struct tegra_bpmp *bpmp)
163 {
164 	struct platform_device *pdev = to_platform_device(bpmp->dev);
165 	struct tegra210_bpmp *priv;
166 	unsigned int i;
167 	int err;
168 
169 	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
170 	if (!priv)
171 		return -ENOMEM;
172 
173 	bpmp->priv = priv;
174 
175 	priv->atomics = devm_platform_ioremap_resource(pdev, 0);
176 	if (IS_ERR(priv->atomics))
177 		return PTR_ERR(priv->atomics);
178 
179 	priv->arb_sema = devm_platform_ioremap_resource(pdev, 1);
180 	if (IS_ERR(priv->arb_sema))
181 		return PTR_ERR(priv->arb_sema);
182 
183 	err = tegra210_bpmp_channel_init(bpmp->tx_channel, bpmp,
184 					 bpmp->soc->channels.cpu_tx.offset);
185 	if (err < 0)
186 		return err;
187 
188 	err = tegra210_bpmp_channel_init(bpmp->rx_channel, bpmp,
189 					 bpmp->soc->channels.cpu_rx.offset);
190 	if (err < 0)
191 		return err;
192 
193 	for (i = 0; i < bpmp->threaded.count; i++) {
194 		unsigned int index = bpmp->soc->channels.thread.offset + i;
195 
196 		err = tegra210_bpmp_channel_init(&bpmp->threaded_channels[i],
197 						 bpmp, index);
198 		if (err < 0)
199 			return err;
200 	}
201 
202 	err = platform_get_irq_byname(pdev, "tx");
203 	if (err < 0)
204 		return err;
205 
206 	priv->tx_irq_data = irq_get_irq_data(err);
207 	if (!priv->tx_irq_data) {
208 		dev_err(&pdev->dev, "failed to get IRQ data for TX IRQ\n");
209 		return -ENOENT;
210 	}
211 
212 	err = platform_get_irq_byname(pdev, "rx");
213 	if (err < 0)
214 		return err;
215 
216 	err = devm_request_irq(&pdev->dev, err, rx_irq,
217 			       IRQF_NO_SUSPEND, dev_name(&pdev->dev), bpmp);
218 	if (err < 0) {
219 		dev_err(&pdev->dev, "failed to request IRQ: %d\n", err);
220 		return err;
221 	}
222 
223 	return 0;
224 }
225 
226 const struct tegra_bpmp_ops tegra210_bpmp_ops = {
227 	.init = tegra210_bpmp_init,
228 	.is_response_ready = tegra210_bpmp_is_response_ready,
229 	.is_request_ready = tegra210_bpmp_is_request_ready,
230 	.ack_response = tegra210_bpmp_ack_response,
231 	.ack_request = tegra210_bpmp_ack_request,
232 	.is_response_channel_free = tegra210_bpmp_is_response_channel_free,
233 	.is_request_channel_free = tegra210_bpmp_is_request_channel_free,
234 	.post_response = tegra210_bpmp_post_response,
235 	.post_request = tegra210_bpmp_post_request,
236 	.ring_doorbell = tegra210_bpmp_ring_doorbell,
237 };
238