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63c13d61 EL |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | // | |
3 | // Copyright (c) 2019 MediaTek Inc. | |
4 | ||
5 | #include <asm/barrier.h> | |
6 | #include <linux/clk.h> | |
7 | #include <linux/err.h> | |
8 | #include <linux/io.h> | |
fad151d5 | 9 | #include <linux/iopoll.h> |
63c13d61 EL |
10 | #include <linux/kernel.h> |
11 | #include <linux/module.h> | |
12 | #include <linux/platform_device.h> | |
fad151d5 | 13 | #include <linux/time64.h> |
63c13d61 EL |
14 | #include <linux/remoteproc/mtk_scp.h> |
15 | ||
16 | #include "mtk_common.h" | |
17 | ||
fad151d5 ADR |
18 | #define SCP_TIMEOUT_US (2000 * USEC_PER_MSEC) |
19 | ||
63c13d61 EL |
20 | /** |
21 | * scp_ipi_register() - register an ipi function | |
22 | * | |
23 | * @scp: mtk_scp structure | |
24 | * @id: IPI ID | |
25 | * @handler: IPI handler | |
26 | * @priv: private data for IPI handler | |
27 | * | |
28 | * Register an ipi function to receive ipi interrupt from SCP. | |
29 | * | |
8f86e695 | 30 | * Return: 0 if ipi registers successfully, -error on error. |
63c13d61 EL |
31 | */ |
32 | int scp_ipi_register(struct mtk_scp *scp, | |
33 | u32 id, | |
34 | scp_ipi_handler_t handler, | |
35 | void *priv) | |
36 | { | |
434ac4d5 | 37 | if (!scp) |
63c13d61 | 38 | return -EPROBE_DEFER; |
63c13d61 EL |
39 | |
40 | if (WARN_ON(id >= SCP_IPI_MAX) || WARN_ON(handler == NULL)) | |
41 | return -EINVAL; | |
42 | ||
43 | scp_ipi_lock(scp, id); | |
44 | scp->ipi_desc[id].handler = handler; | |
45 | scp->ipi_desc[id].priv = priv; | |
46 | scp_ipi_unlock(scp, id); | |
47 | ||
48 | return 0; | |
49 | } | |
50 | EXPORT_SYMBOL_GPL(scp_ipi_register); | |
51 | ||
52 | /** | |
53 | * scp_ipi_unregister() - unregister an ipi function | |
54 | * | |
55 | * @scp: mtk_scp structure | |
56 | * @id: IPI ID | |
57 | * | |
58 | * Unregister an ipi function to receive ipi interrupt from SCP. | |
59 | */ | |
60 | void scp_ipi_unregister(struct mtk_scp *scp, u32 id) | |
61 | { | |
62 | if (!scp) | |
63 | return; | |
64 | ||
65 | if (WARN_ON(id >= SCP_IPI_MAX)) | |
66 | return; | |
67 | ||
68 | scp_ipi_lock(scp, id); | |
69 | scp->ipi_desc[id].handler = NULL; | |
70 | scp->ipi_desc[id].priv = NULL; | |
71 | scp_ipi_unlock(scp, id); | |
72 | } | |
73 | EXPORT_SYMBOL_GPL(scp_ipi_unregister); | |
74 | ||
75 | /* | |
76 | * scp_memcpy_aligned() - Copy src to dst, where dst is in SCP SRAM region. | |
77 | * | |
78 | * @dst: Pointer to the destination buffer, should be in SCP SRAM region. | |
79 | * @src: Pointer to the source buffer. | |
80 | * @len: Length of the source buffer to be copied. | |
81 | * | |
82 | * Since AP access of SCP SRAM don't support byte write, this always write a | |
83 | * full word at a time, and may cause some extra bytes to be written at the | |
84 | * beginning & ending of dst. | |
85 | */ | |
86 | void scp_memcpy_aligned(void __iomem *dst, const void *src, unsigned int len) | |
87 | { | |
88 | void __iomem *ptr; | |
89 | u32 val; | |
90 | unsigned int i = 0, remain; | |
91 | ||
92 | if (!IS_ALIGNED((unsigned long)dst, 4)) { | |
93 | ptr = (void __iomem *)ALIGN_DOWN((unsigned long)dst, 4); | |
94 | i = 4 - (dst - ptr); | |
95 | val = readl_relaxed(ptr); | |
96 | memcpy((u8 *)&val + (4 - i), src, i); | |
97 | writel_relaxed(val, ptr); | |
98 | } | |
99 | ||
100 | __iowrite32_copy(dst + i, src + i, (len - i) / 4); | |
101 | remain = (len - i) % 4; | |
102 | ||
103 | if (remain > 0) { | |
104 | val = readl_relaxed(dst + len - remain); | |
105 | memcpy(&val, src + len - remain, remain); | |
106 | writel_relaxed(val, dst + len - remain); | |
107 | } | |
108 | } | |
109 | EXPORT_SYMBOL_GPL(scp_memcpy_aligned); | |
110 | ||
111 | /** | |
112 | * scp_ipi_lock() - Lock before operations of an IPI ID | |
113 | * | |
114 | * @scp: mtk_scp structure | |
115 | * @id: IPI ID | |
116 | * | |
117 | * Note: This should not be used by drivers other than mtk_scp. | |
118 | */ | |
119 | void scp_ipi_lock(struct mtk_scp *scp, u32 id) | |
120 | { | |
121 | if (WARN_ON(id >= SCP_IPI_MAX)) | |
122 | return; | |
123 | mutex_lock(&scp->ipi_desc[id].lock); | |
124 | } | |
125 | EXPORT_SYMBOL_GPL(scp_ipi_lock); | |
126 | ||
127 | /** | |
e1996799 | 128 | * scp_ipi_unlock() - Unlock after operations of an IPI ID |
63c13d61 EL |
129 | * |
130 | * @scp: mtk_scp structure | |
131 | * @id: IPI ID | |
132 | * | |
133 | * Note: This should not be used by drivers other than mtk_scp. | |
134 | */ | |
135 | void scp_ipi_unlock(struct mtk_scp *scp, u32 id) | |
136 | { | |
137 | if (WARN_ON(id >= SCP_IPI_MAX)) | |
138 | return; | |
139 | mutex_unlock(&scp->ipi_desc[id].lock); | |
140 | } | |
141 | EXPORT_SYMBOL_GPL(scp_ipi_unlock); | |
142 | ||
143 | /** | |
144 | * scp_ipi_send() - send data from AP to scp. | |
145 | * | |
146 | * @scp: mtk_scp structure | |
147 | * @id: IPI ID | |
148 | * @buf: the data buffer | |
149 | * @len: the data buffer length | |
150 | * @wait: number of msecs to wait for ack. 0 to skip waiting. | |
151 | * | |
152 | * This function is thread-safe. When this function returns, | |
153 | * SCP has received the data and starts the processing. | |
154 | * When the processing completes, IPI handler registered | |
155 | * by scp_ipi_register will be called in interrupt context. | |
156 | * | |
8f86e695 | 157 | * Return: 0 if sending data successfully, -error on error. |
63c13d61 EL |
158 | **/ |
159 | int scp_ipi_send(struct mtk_scp *scp, u32 id, void *buf, unsigned int len, | |
160 | unsigned int wait) | |
161 | { | |
162 | struct mtk_share_obj __iomem *send_obj = scp->send_buf; | |
fad151d5 | 163 | u32 val; |
63c13d61 EL |
164 | int ret; |
165 | ||
166 | if (WARN_ON(id <= SCP_IPI_INIT) || WARN_ON(id >= SCP_IPI_MAX) || | |
70179969 | 167 | WARN_ON(id == SCP_IPI_NS_SERVICE) || |
63c13d61 EL |
168 | WARN_ON(len > sizeof(send_obj->share_buf)) || WARN_ON(!buf)) |
169 | return -EINVAL; | |
170 | ||
63c13d61 EL |
171 | ret = clk_prepare_enable(scp->clk); |
172 | if (ret) { | |
173 | dev_err(scp->dev, "failed to enable clock\n"); | |
e46ceea3 | 174 | return ret; |
63c13d61 EL |
175 | } |
176 | ||
e46ceea3 CYT |
177 | mutex_lock(&scp->send_lock); |
178 | ||
63c13d61 | 179 | /* Wait until SCP receives the last command */ |
9ea16669 | 180 | ret = readl_poll_timeout_atomic(scp->cluster->reg_base + scp->data->host_to_scp_reg, |
fad151d5 ADR |
181 | val, !val, 0, SCP_TIMEOUT_US); |
182 | if (ret) { | |
183 | dev_err(scp->dev, "%s: IPI timeout!\n", __func__); | |
184 | goto unlock_mutex; | |
185 | } | |
63c13d61 EL |
186 | |
187 | scp_memcpy_aligned(send_obj->share_buf, buf, len); | |
188 | ||
189 | writel(len, &send_obj->len); | |
190 | writel(id, &send_obj->id); | |
191 | ||
192 | scp->ipi_id_ack[id] = false; | |
193 | /* send the command to SCP */ | |
fd0b6c1f | 194 | writel(scp->data->host_to_scp_int_bit, |
9ea16669 | 195 | scp->cluster->reg_base + scp->data->host_to_scp_reg); |
63c13d61 EL |
196 | |
197 | if (wait) { | |
198 | /* wait for SCP's ACK */ | |
63c13d61 EL |
199 | ret = wait_event_timeout(scp->ack_wq, |
200 | scp->ipi_id_ack[id], | |
ac8723e8 | 201 | msecs_to_jiffies(wait)); |
63c13d61 EL |
202 | scp->ipi_id_ack[id] = false; |
203 | if (WARN(!ret, "scp ipi %d ack time out !", id)) | |
204 | ret = -EIO; | |
205 | else | |
206 | ret = 0; | |
207 | } | |
208 | ||
63c13d61 EL |
209 | unlock_mutex: |
210 | mutex_unlock(&scp->send_lock); | |
e46ceea3 | 211 | clk_disable_unprepare(scp->clk); |
63c13d61 EL |
212 | |
213 | return ret; | |
214 | } | |
215 | EXPORT_SYMBOL_GPL(scp_ipi_send); | |
216 | ||
217 | MODULE_LICENSE("GPL v2"); | |
218 | MODULE_DESCRIPTION("MediaTek scp IPI interface"); |