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/iopoll.h> |
10 | #include <linux/kernel.h> |
11 | #include <linux/module.h> |
12 | #include <linux/platform_device.h> |
13 | #include <linux/time64.h> |
14 | #include <linux/remoteproc/mtk_scp.h> |
15 | |
16 | #include "mtk_common.h" |
17 | |
18 | #define SCP_TIMEOUT_US (2000 * USEC_PER_MSEC) |
19 | |
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 | * |
30 | * Return: 0 if ipi registers successfully, -error on error. |
31 | */ |
32 | int scp_ipi_register(struct mtk_scp *scp, |
33 | u32 id, |
34 | scp_ipi_handler_t handler, |
35 | void *priv) |
36 | { |
37 | if (!scp) |
38 | return -EPROBE_DEFER; |
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(to: dst + i, from: src + i, count: (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 | /** |
128 | * scp_ipi_unlock() - Unlock after operations of an IPI ID |
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(lock: &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 | * |
157 | * Return: 0 if sending data successfully, -error on error. |
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; |
163 | u32 val; |
164 | int ret; |
165 | |
166 | if (WARN_ON(id <= SCP_IPI_INIT) || WARN_ON(id >= SCP_IPI_MAX) || |
167 | WARN_ON(id == SCP_IPI_NS_SERVICE) || |
168 | WARN_ON(len > sizeof(send_obj->share_buf)) || WARN_ON(!buf)) |
169 | return -EINVAL; |
170 | |
171 | ret = clk_prepare_enable(clk: scp->clk); |
172 | if (ret) { |
173 | dev_err(scp->dev, "failed to enable clock\n" ); |
174 | return ret; |
175 | } |
176 | |
177 | mutex_lock(&scp->send_lock); |
178 | |
179 | /* Wait until SCP receives the last command */ |
180 | ret = readl_poll_timeout_atomic(scp->cluster->reg_base + scp->data->host_to_scp_reg, |
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 | } |
186 | |
187 | scp_memcpy_aligned(send_obj->share_buf, buf, len); |
188 | |
189 | writel(val: len, addr: &send_obj->len); |
190 | writel(val: id, addr: &send_obj->id); |
191 | |
192 | scp->ipi_id_ack[id] = false; |
193 | /* send the command to SCP */ |
194 | writel(val: scp->data->host_to_scp_int_bit, |
195 | addr: scp->cluster->reg_base + scp->data->host_to_scp_reg); |
196 | |
197 | if (wait) { |
198 | /* wait for SCP's ACK */ |
199 | ret = wait_event_timeout(scp->ack_wq, |
200 | scp->ipi_id_ack[id], |
201 | msecs_to_jiffies(wait)); |
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 | unlock_mutex: |
210 | mutex_unlock(lock: &scp->send_lock); |
211 | clk_disable_unprepare(clk: scp->clk); |
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" ); |
219 | |