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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> | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/module.h> | |
11 | #include <linux/platform_device.h> | |
12 | #include <linux/remoteproc/mtk_scp.h> | |
13 | ||
14 | #include "mtk_common.h" | |
15 | ||
16 | /** | |
17 | * scp_ipi_register() - register an ipi function | |
18 | * | |
19 | * @scp: mtk_scp structure | |
20 | * @id: IPI ID | |
21 | * @handler: IPI handler | |
22 | * @priv: private data for IPI handler | |
23 | * | |
24 | * Register an ipi function to receive ipi interrupt from SCP. | |
25 | * | |
26 | * Returns 0 if ipi registers successfully, -error on error. | |
27 | */ | |
28 | int scp_ipi_register(struct mtk_scp *scp, | |
29 | u32 id, | |
30 | scp_ipi_handler_t handler, | |
31 | void *priv) | |
32 | { | |
33 | if (!scp) { | |
34 | dev_err(scp->dev, "scp device is not ready\n"); | |
35 | return -EPROBE_DEFER; | |
36 | } | |
37 | ||
38 | if (WARN_ON(id >= SCP_IPI_MAX) || WARN_ON(handler == NULL)) | |
39 | return -EINVAL; | |
40 | ||
41 | scp_ipi_lock(scp, id); | |
42 | scp->ipi_desc[id].handler = handler; | |
43 | scp->ipi_desc[id].priv = priv; | |
44 | scp_ipi_unlock(scp, id); | |
45 | ||
46 | return 0; | |
47 | } | |
48 | EXPORT_SYMBOL_GPL(scp_ipi_register); | |
49 | ||
50 | /** | |
51 | * scp_ipi_unregister() - unregister an ipi function | |
52 | * | |
53 | * @scp: mtk_scp structure | |
54 | * @id: IPI ID | |
55 | * | |
56 | * Unregister an ipi function to receive ipi interrupt from SCP. | |
57 | */ | |
58 | void scp_ipi_unregister(struct mtk_scp *scp, u32 id) | |
59 | { | |
60 | if (!scp) | |
61 | return; | |
62 | ||
63 | if (WARN_ON(id >= SCP_IPI_MAX)) | |
64 | return; | |
65 | ||
66 | scp_ipi_lock(scp, id); | |
67 | scp->ipi_desc[id].handler = NULL; | |
68 | scp->ipi_desc[id].priv = NULL; | |
69 | scp_ipi_unlock(scp, id); | |
70 | } | |
71 | EXPORT_SYMBOL_GPL(scp_ipi_unregister); | |
72 | ||
73 | /* | |
74 | * scp_memcpy_aligned() - Copy src to dst, where dst is in SCP SRAM region. | |
75 | * | |
76 | * @dst: Pointer to the destination buffer, should be in SCP SRAM region. | |
77 | * @src: Pointer to the source buffer. | |
78 | * @len: Length of the source buffer to be copied. | |
79 | * | |
80 | * Since AP access of SCP SRAM don't support byte write, this always write a | |
81 | * full word at a time, and may cause some extra bytes to be written at the | |
82 | * beginning & ending of dst. | |
83 | */ | |
84 | void scp_memcpy_aligned(void __iomem *dst, const void *src, unsigned int len) | |
85 | { | |
86 | void __iomem *ptr; | |
87 | u32 val; | |
88 | unsigned int i = 0, remain; | |
89 | ||
90 | if (!IS_ALIGNED((unsigned long)dst, 4)) { | |
91 | ptr = (void __iomem *)ALIGN_DOWN((unsigned long)dst, 4); | |
92 | i = 4 - (dst - ptr); | |
93 | val = readl_relaxed(ptr); | |
94 | memcpy((u8 *)&val + (4 - i), src, i); | |
95 | writel_relaxed(val, ptr); | |
96 | } | |
97 | ||
98 | __iowrite32_copy(dst + i, src + i, (len - i) / 4); | |
99 | remain = (len - i) % 4; | |
100 | ||
101 | if (remain > 0) { | |
102 | val = readl_relaxed(dst + len - remain); | |
103 | memcpy(&val, src + len - remain, remain); | |
104 | writel_relaxed(val, dst + len - remain); | |
105 | } | |
106 | } | |
107 | EXPORT_SYMBOL_GPL(scp_memcpy_aligned); | |
108 | ||
109 | /** | |
110 | * scp_ipi_lock() - Lock before operations of an IPI ID | |
111 | * | |
112 | * @scp: mtk_scp structure | |
113 | * @id: IPI ID | |
114 | * | |
115 | * Note: This should not be used by drivers other than mtk_scp. | |
116 | */ | |
117 | void scp_ipi_lock(struct mtk_scp *scp, u32 id) | |
118 | { | |
119 | if (WARN_ON(id >= SCP_IPI_MAX)) | |
120 | return; | |
121 | mutex_lock(&scp->ipi_desc[id].lock); | |
122 | } | |
123 | EXPORT_SYMBOL_GPL(scp_ipi_lock); | |
124 | ||
125 | /** | |
126 | * scp_ipi_lock() - Unlock after operations of an IPI ID | |
127 | * | |
128 | * @scp: mtk_scp structure | |
129 | * @id: IPI ID | |
130 | * | |
131 | * Note: This should not be used by drivers other than mtk_scp. | |
132 | */ | |
133 | void scp_ipi_unlock(struct mtk_scp *scp, u32 id) | |
134 | { | |
135 | if (WARN_ON(id >= SCP_IPI_MAX)) | |
136 | return; | |
137 | mutex_unlock(&scp->ipi_desc[id].lock); | |
138 | } | |
139 | EXPORT_SYMBOL_GPL(scp_ipi_unlock); | |
140 | ||
141 | /** | |
142 | * scp_ipi_send() - send data from AP to scp. | |
143 | * | |
144 | * @scp: mtk_scp structure | |
145 | * @id: IPI ID | |
146 | * @buf: the data buffer | |
147 | * @len: the data buffer length | |
148 | * @wait: number of msecs to wait for ack. 0 to skip waiting. | |
149 | * | |
150 | * This function is thread-safe. When this function returns, | |
151 | * SCP has received the data and starts the processing. | |
152 | * When the processing completes, IPI handler registered | |
153 | * by scp_ipi_register will be called in interrupt context. | |
154 | * | |
155 | * Returns 0 if sending data successfully, -error on error. | |
156 | **/ | |
157 | int scp_ipi_send(struct mtk_scp *scp, u32 id, void *buf, unsigned int len, | |
158 | unsigned int wait) | |
159 | { | |
160 | struct mtk_share_obj __iomem *send_obj = scp->send_buf; | |
161 | unsigned long timeout; | |
162 | int ret; | |
163 | ||
164 | if (WARN_ON(id <= SCP_IPI_INIT) || WARN_ON(id >= SCP_IPI_MAX) || | |
70179969 | 165 | WARN_ON(id == SCP_IPI_NS_SERVICE) || |
63c13d61 EL |
166 | WARN_ON(len > sizeof(send_obj->share_buf)) || WARN_ON(!buf)) |
167 | return -EINVAL; | |
168 | ||
169 | mutex_lock(&scp->send_lock); | |
170 | ||
171 | ret = clk_prepare_enable(scp->clk); | |
172 | if (ret) { | |
173 | dev_err(scp->dev, "failed to enable clock\n"); | |
174 | goto unlock_mutex; | |
175 | } | |
176 | ||
177 | /* Wait until SCP receives the last command */ | |
178 | timeout = jiffies + msecs_to_jiffies(2000); | |
179 | do { | |
180 | if (time_after(jiffies, timeout)) { | |
181 | dev_err(scp->dev, "%s: IPI timeout!\n", __func__); | |
182 | ret = -ETIMEDOUT; | |
183 | goto clock_disable; | |
184 | } | |
185 | } while (readl(scp->reg_base + MT8183_HOST_TO_SCP)); | |
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 */ | |
194 | writel(MT8183_HOST_IPC_INT_BIT, scp->reg_base + MT8183_HOST_TO_SCP); | |
195 | ||
196 | if (wait) { | |
197 | /* wait for SCP's ACK */ | |
198 | timeout = msecs_to_jiffies(wait); | |
199 | ret = wait_event_timeout(scp->ack_wq, | |
200 | scp->ipi_id_ack[id], | |
201 | timeout); | |
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 | ||
209 | clock_disable: | |
210 | clk_disable_unprepare(scp->clk); | |
211 | unlock_mutex: | |
212 | mutex_unlock(&scp->send_lock); | |
213 | ||
214 | return ret; | |
215 | } | |
216 | EXPORT_SYMBOL_GPL(scp_ipi_send); | |
217 | ||
218 | MODULE_LICENSE("GPL v2"); | |
219 | MODULE_DESCRIPTION("MediaTek scp IPI interface"); |