1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (C) 2020 MediaTek Inc.
4 */
5
6 #include <linux/clk.h>
7 #include <linux/interrupt.h>
8 #include <linux/iopoll.h>
9 #include <linux/module.h>
10 #include <linux/platform_device.h>
11 #include <linux/of.h>
12 #include <linux/of_irq.h>
13 #include <linux/of_address.h>
14
15 #define VIO_MOD_TO_REG_IND(m) ((m) / 32)
16 #define VIO_MOD_TO_REG_OFF(m) ((m) % 32)
17
18 struct mtk_devapc_vio_dbgs {
19 union {
20 u32 vio_dbg0;
21 struct {
22 u32 mstid:16;
23 u32 dmnid:6;
24 u32 vio_w:1;
25 u32 vio_r:1;
26 u32 addr_h:4;
27 u32 resv:4;
28 } dbg0_bits;
29 };
30
31 u32 vio_dbg1;
32 };
33
34 struct mtk_devapc_regs_ofs {
35 /* reg offset */
36 u32 vio_mask_offset;
37 u32 vio_sta_offset;
38 u32 vio_dbg0_offset;
39 u32 vio_dbg1_offset;
40 u32 apc_con_offset;
41 u32 vio_shift_sta_offset;
42 u32 vio_shift_sel_offset;
43 u32 vio_shift_con_offset;
44 };
45
46 struct mtk_devapc_data {
47 /* numbers of violation index */
48 u32 vio_idx_num;
49 const struct mtk_devapc_regs_ofs *regs_ofs;
50 };
51
52 struct mtk_devapc_context {
53 struct device *dev;
54 void __iomem *infra_base;
55 struct clk *infra_clk;
56 const struct mtk_devapc_data *data;
57 };
58
clear_vio_status(struct mtk_devapc_context * ctx)59 static void clear_vio_status(struct mtk_devapc_context *ctx)
60 {
61 void __iomem *reg;
62 int i;
63
64 reg = ctx->infra_base + ctx->data->regs_ofs->vio_sta_offset;
65
66 for (i = 0; i < VIO_MOD_TO_REG_IND(ctx->data->vio_idx_num) - 1; i++)
67 writel(GENMASK(31, 0), reg + 4 * i);
68
69 writel(GENMASK(VIO_MOD_TO_REG_OFF(ctx->data->vio_idx_num) - 1, 0),
70 reg + 4 * i);
71 }
72
mask_module_irq(struct mtk_devapc_context * ctx,bool mask)73 static void mask_module_irq(struct mtk_devapc_context *ctx, bool mask)
74 {
75 void __iomem *reg;
76 u32 val;
77 int i;
78
79 reg = ctx->infra_base + ctx->data->regs_ofs->vio_mask_offset;
80
81 if (mask)
82 val = GENMASK(31, 0);
83 else
84 val = 0;
85
86 for (i = 0; i < VIO_MOD_TO_REG_IND(ctx->data->vio_idx_num) - 1; i++)
87 writel(val, reg + 4 * i);
88
89 val = readl(reg + 4 * i);
90 if (mask)
91 val |= GENMASK(VIO_MOD_TO_REG_OFF(ctx->data->vio_idx_num) - 1,
92 0);
93 else
94 val &= ~GENMASK(VIO_MOD_TO_REG_OFF(ctx->data->vio_idx_num) - 1,
95 0);
96
97 writel(val, reg + 4 * i);
98 }
99
100 #define PHY_DEVAPC_TIMEOUT 0x10000
101
102 /*
103 * devapc_sync_vio_dbg - do "shift" mechansim" to get full violation information.
104 * shift mechanism is depends on devapc hardware design.
105 * Mediatek devapc set multiple slaves as a group.
106 * When violation is triggered, violation info is kept
107 * inside devapc hardware.
108 * Driver should do shift mechansim to sync full violation
109 * info to VIO_DBGs registers.
110 *
111 */
devapc_sync_vio_dbg(struct mtk_devapc_context * ctx)112 static int devapc_sync_vio_dbg(struct mtk_devapc_context *ctx)
113 {
114 void __iomem *pd_vio_shift_sta_reg;
115 void __iomem *pd_vio_shift_sel_reg;
116 void __iomem *pd_vio_shift_con_reg;
117 int min_shift_group;
118 int ret;
119 u32 val;
120
121 pd_vio_shift_sta_reg = ctx->infra_base +
122 ctx->data->regs_ofs->vio_shift_sta_offset;
123 pd_vio_shift_sel_reg = ctx->infra_base +
124 ctx->data->regs_ofs->vio_shift_sel_offset;
125 pd_vio_shift_con_reg = ctx->infra_base +
126 ctx->data->regs_ofs->vio_shift_con_offset;
127
128 /* Find the minimum shift group which has violation */
129 val = readl(pd_vio_shift_sta_reg);
130 if (!val)
131 return false;
132
133 min_shift_group = __ffs(val);
134
135 /* Assign the group to sync */
136 writel(0x1 << min_shift_group, pd_vio_shift_sel_reg);
137
138 /* Start syncing */
139 writel(0x1, pd_vio_shift_con_reg);
140
141 ret = readl_poll_timeout(pd_vio_shift_con_reg, val, val == 0x3, 0,
142 PHY_DEVAPC_TIMEOUT);
143 if (ret) {
144 dev_err(ctx->dev, "%s: Shift violation info failed\n", __func__);
145 return false;
146 }
147
148 /* Stop syncing */
149 writel(0x0, pd_vio_shift_con_reg);
150
151 /* Write clear */
152 writel(0x1 << min_shift_group, pd_vio_shift_sta_reg);
153
154 return true;
155 }
156
157 /*
158 * devapc_extract_vio_dbg - extract full violation information after doing
159 * shift mechanism.
160 */
devapc_extract_vio_dbg(struct mtk_devapc_context * ctx)161 static void devapc_extract_vio_dbg(struct mtk_devapc_context *ctx)
162 {
163 struct mtk_devapc_vio_dbgs vio_dbgs;
164 void __iomem *vio_dbg0_reg;
165 void __iomem *vio_dbg1_reg;
166
167 vio_dbg0_reg = ctx->infra_base + ctx->data->regs_ofs->vio_dbg0_offset;
168 vio_dbg1_reg = ctx->infra_base + ctx->data->regs_ofs->vio_dbg1_offset;
169
170 vio_dbgs.vio_dbg0 = readl(vio_dbg0_reg);
171 vio_dbgs.vio_dbg1 = readl(vio_dbg1_reg);
172
173 /* Print violation information */
174 if (vio_dbgs.dbg0_bits.vio_w)
175 dev_info(ctx->dev, "Write Violation\n");
176 else if (vio_dbgs.dbg0_bits.vio_r)
177 dev_info(ctx->dev, "Read Violation\n");
178
179 dev_info(ctx->dev, "Bus ID:0x%x, Dom ID:0x%x, Vio Addr:0x%x\n",
180 vio_dbgs.dbg0_bits.mstid, vio_dbgs.dbg0_bits.dmnid,
181 vio_dbgs.vio_dbg1);
182 }
183
184 /*
185 * devapc_violation_irq - the devapc Interrupt Service Routine (ISR) will dump
186 * violation information including which master violates
187 * access slave.
188 */
devapc_violation_irq(int irq_number,void * data)189 static irqreturn_t devapc_violation_irq(int irq_number, void *data)
190 {
191 struct mtk_devapc_context *ctx = data;
192
193 while (devapc_sync_vio_dbg(ctx))
194 devapc_extract_vio_dbg(ctx);
195
196 clear_vio_status(ctx);
197
198 return IRQ_HANDLED;
199 }
200
201 /*
202 * start_devapc - unmask slave's irq to start receiving devapc violation.
203 */
start_devapc(struct mtk_devapc_context * ctx)204 static void start_devapc(struct mtk_devapc_context *ctx)
205 {
206 writel(BIT(31), ctx->infra_base + ctx->data->regs_ofs->apc_con_offset);
207
208 mask_module_irq(ctx, false);
209 }
210
211 /*
212 * stop_devapc - mask slave's irq to stop service.
213 */
stop_devapc(struct mtk_devapc_context * ctx)214 static void stop_devapc(struct mtk_devapc_context *ctx)
215 {
216 mask_module_irq(ctx, true);
217
218 writel(BIT(2), ctx->infra_base + ctx->data->regs_ofs->apc_con_offset);
219 }
220
221 static const struct mtk_devapc_regs_ofs devapc_regs_ofs_mt6779 = {
222 .vio_mask_offset = 0x0,
223 .vio_sta_offset = 0x400,
224 .vio_dbg0_offset = 0x900,
225 .vio_dbg1_offset = 0x904,
226 .apc_con_offset = 0xF00,
227 .vio_shift_sta_offset = 0xF10,
228 .vio_shift_sel_offset = 0xF14,
229 .vio_shift_con_offset = 0xF20,
230 };
231
232 static const struct mtk_devapc_data devapc_mt6779 = {
233 .vio_idx_num = 511,
234 .regs_ofs = &devapc_regs_ofs_mt6779,
235 };
236
237 static const struct mtk_devapc_data devapc_mt8186 = {
238 .vio_idx_num = 519,
239 .regs_ofs = &devapc_regs_ofs_mt6779,
240 };
241
242 static const struct of_device_id mtk_devapc_dt_match[] = {
243 {
244 .compatible = "mediatek,mt6779-devapc",
245 .data = &devapc_mt6779,
246 }, {
247 .compatible = "mediatek,mt8186-devapc",
248 .data = &devapc_mt8186,
249 }, {
250 },
251 };
252 MODULE_DEVICE_TABLE(of, mtk_devapc_dt_match);
253
mtk_devapc_probe(struct platform_device * pdev)254 static int mtk_devapc_probe(struct platform_device *pdev)
255 {
256 struct device_node *node = pdev->dev.of_node;
257 struct mtk_devapc_context *ctx;
258 u32 devapc_irq;
259 int ret;
260
261 if (IS_ERR(node))
262 return -ENODEV;
263
264 ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL);
265 if (!ctx)
266 return -ENOMEM;
267
268 ctx->data = of_device_get_match_data(&pdev->dev);
269 ctx->dev = &pdev->dev;
270
271 ctx->infra_base = of_iomap(node, 0);
272 if (!ctx->infra_base)
273 return -EINVAL;
274
275 devapc_irq = irq_of_parse_and_map(node, 0);
276 if (!devapc_irq)
277 return -EINVAL;
278
279 ctx->infra_clk = devm_clk_get_enabled(&pdev->dev, "devapc-infra-clock");
280 if (IS_ERR(ctx->infra_clk))
281 return -EINVAL;
282
283 ret = devm_request_irq(&pdev->dev, devapc_irq, devapc_violation_irq,
284 IRQF_TRIGGER_NONE, "devapc", ctx);
285 if (ret)
286 return ret;
287
288 platform_set_drvdata(pdev, ctx);
289
290 start_devapc(ctx);
291
292 return 0;
293 }
294
mtk_devapc_remove(struct platform_device * pdev)295 static void mtk_devapc_remove(struct platform_device *pdev)
296 {
297 struct mtk_devapc_context *ctx = platform_get_drvdata(pdev);
298
299 stop_devapc(ctx);
300 }
301
302 static struct platform_driver mtk_devapc_driver = {
303 .probe = mtk_devapc_probe,
304 .remove_new = mtk_devapc_remove,
305 .driver = {
306 .name = "mtk-devapc",
307 .of_match_table = mtk_devapc_dt_match,
308 },
309 };
310
311 module_platform_driver(mtk_devapc_driver);
312
313 MODULE_DESCRIPTION("Mediatek Device APC Driver");
314 MODULE_AUTHOR("Neal Liu <neal.liu@mediatek.com>");
315 MODULE_LICENSE("GPL");
316