1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * DMA translation between STA2x11 AMBA memory mapping and the x86 memory mapping
4 *
5 * ST Microelectronics ConneXt (STA2X11/STA2X10)
6 *
7 * Copyright (c) 2010-2011 Wind River Systems, Inc.
8 */
9
10 #include <linux/pci.h>
11 #include <linux/pci_ids.h>
12 #include <linux/export.h>
13 #include <linux/list.h>
14 #include <linux/dma-map-ops.h>
15 #include <linux/swiotlb.h>
16 #include <asm/iommu.h>
17 #include <asm/sta2x11.h>
18
19 #define STA2X11_SWIOTLB_SIZE (4*1024*1024)
20
21 /*
22 * We build a list of bus numbers that are under the ConneXt. The
23 * main bridge hosts 4 busses, which are the 4 endpoints, in order.
24 */
25 #define STA2X11_NR_EP 4 /* 0..3 included */
26 #define STA2X11_NR_FUNCS 8 /* 0..7 included */
27 #define STA2X11_AMBA_SIZE (512 << 20)
28
29 struct sta2x11_ahb_regs { /* saved during suspend */
30 u32 base, pexlbase, pexhbase, crw;
31 };
32
33 struct sta2x11_mapping {
34 int is_suspended;
35 struct sta2x11_ahb_regs regs[STA2X11_NR_FUNCS];
36 };
37
38 struct sta2x11_instance {
39 struct list_head list;
40 int bus0;
41 struct sta2x11_mapping map[STA2X11_NR_EP];
42 };
43
44 static LIST_HEAD(sta2x11_instance_list);
45
46 /* At probe time, record new instances of this bridge (likely one only) */
47 static void sta2x11_new_instance(struct pci_dev *pdev)
48 {
49 struct sta2x11_instance *instance;
50
51 instance = kzalloc(sizeof(*instance), GFP_ATOMIC);
52 if (!instance)
53 return;
54 /* This has a subordinate bridge, with 4 more-subordinate ones */
55 instance->bus0 = pdev->subordinate->number + 1;
56
57 if (list_empty(&sta2x11_instance_list)) {
58 int size = STA2X11_SWIOTLB_SIZE;
59 /* First instance: register your own swiotlb area */
60 dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size);
61 if (swiotlb_init_late(size, GFP_DMA, NULL))
62 dev_emerg(&pdev->dev, "init swiotlb failed\n");
63 }
64 list_add(&instance->list, &sta2x11_instance_list);
65 }
66 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, 0xcc17, sta2x11_new_instance);
67
68 /*
69 * Utility functions used in this file from below
70 */
71 static struct sta2x11_instance *sta2x11_pdev_to_instance(struct pci_dev *pdev)
72 {
73 struct sta2x11_instance *instance;
74 int ep;
75
76 list_for_each_entry(instance, &sta2x11_instance_list, list) {
77 ep = pdev->bus->number - instance->bus0;
78 if (ep >= 0 && ep < STA2X11_NR_EP)
79 return instance;
80 }
81 return NULL;
82 }
83
84 static int sta2x11_pdev_to_ep(struct pci_dev *pdev)
85 {
86 struct sta2x11_instance *instance;
87
88 instance = sta2x11_pdev_to_instance(pdev);
89 if (!instance)
90 return -1;
91
92 return pdev->bus->number - instance->bus0;
93 }
94
95 /* This is exported, as some devices need to access the MFD registers */
96 struct sta2x11_instance *sta2x11_get_instance(struct pci_dev *pdev)
97 {
98 return sta2x11_pdev_to_instance(pdev);
99 }
100 EXPORT_SYMBOL(sta2x11_get_instance);
101
102 /* At setup time, we use our own ops if the device is a ConneXt one */
103 static void sta2x11_setup_pdev(struct pci_dev *pdev)
104 {
105 struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev);
106
107 if (!instance) /* either a sta2x11 bridge or another ST device */
108 return;
109
110 /* We must enable all devices as master, for audio DMA to work */
111 pci_set_master(pdev);
112 }
113 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_setup_pdev);
114
115 /*
116 * At boot we must set up the mappings for the pcie-to-amba bridge.
117 * It involves device access, and the same happens at suspend/resume time
118 */
119
120 #define AHB_MAPB 0xCA4
121 #define AHB_CRW(i) (AHB_MAPB + 0 + (i) * 0x10)
122 #define AHB_CRW_SZMASK 0xfffffc00UL
123 #define AHB_CRW_ENABLE (1 << 0)
124 #define AHB_CRW_WTYPE_MEM (2 << 1)
125 #define AHB_CRW_ROE (1UL << 3) /* Relax Order Ena */
126 #define AHB_CRW_NSE (1UL << 4) /* No Snoop Enable */
127 #define AHB_BASE(i) (AHB_MAPB + 4 + (i) * 0x10)
128 #define AHB_PEXLBASE(i) (AHB_MAPB + 8 + (i) * 0x10)
129 #define AHB_PEXHBASE(i) (AHB_MAPB + 12 + (i) * 0x10)
130
131 /* At probe time, enable mapping for each endpoint, using the pdev */
132 static void sta2x11_map_ep(struct pci_dev *pdev)
133 {
134 struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev);
135 struct device *dev = &pdev->dev;
136 u32 amba_base, max_amba_addr;
137 int i, ret;
138
139 if (!instance)
140 return;
141
142 pci_read_config_dword(pdev, AHB_BASE(0), &amba_base);
143 max_amba_addr = amba_base + STA2X11_AMBA_SIZE - 1;
144
145 ret = dma_direct_set_offset(dev, 0, amba_base, STA2X11_AMBA_SIZE);
146 if (ret)
147 dev_err(dev, "sta2x11: could not set DMA offset\n");
148
149 dev->bus_dma_limit = max_amba_addr;
150 dma_set_mask_and_coherent(&pdev->dev, max_amba_addr);
151
152 /* Configure AHB mapping */
153 pci_write_config_dword(pdev, AHB_PEXLBASE(0), 0);
154 pci_write_config_dword(pdev, AHB_PEXHBASE(0), 0);
155 pci_write_config_dword(pdev, AHB_CRW(0), STA2X11_AMBA_SIZE |
156 AHB_CRW_WTYPE_MEM | AHB_CRW_ENABLE);
157
158 /* Disable all the other windows */
159 for (i = 1; i < STA2X11_NR_FUNCS; i++)
160 pci_write_config_dword(pdev, AHB_CRW(i), 0);
161
162 dev_info(&pdev->dev,
163 "sta2x11: Map EP %i: AMBA address %#8x-%#8x\n",
164 sta2x11_pdev_to_ep(pdev), amba_base, max_amba_addr);
165 }
166 DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_map_ep);
167
168 #ifdef CONFIG_PM /* Some register values must be saved and restored */
169
170 static struct sta2x11_mapping *sta2x11_pdev_to_mapping(struct pci_dev *pdev)
171 {
172 struct sta2x11_instance *instance;
173 int ep;
174
175 instance = sta2x11_pdev_to_instance(pdev);
176 if (!instance)
177 return NULL;
178 ep = sta2x11_pdev_to_ep(pdev);
179 return instance->map + ep;
180 }
181
182 static void suspend_mapping(struct pci_dev *pdev)
183 {
184 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
185 int i;
186
187 if (!map)
188 return;
189
190 if (map->is_suspended)
191 return;
192 map->is_suspended = 1;
193
194 /* Save all window configs */
195 for (i = 0; i < STA2X11_NR_FUNCS; i++) {
196 struct sta2x11_ahb_regs *regs = map->regs + i;
197
198 pci_read_config_dword(pdev, AHB_BASE(i), ®s->base);
199 pci_read_config_dword(pdev, AHB_PEXLBASE(i), ®s->pexlbase);
200 pci_read_config_dword(pdev, AHB_PEXHBASE(i), ®s->pexhbase);
201 pci_read_config_dword(pdev, AHB_CRW(i), ®s->crw);
202 }
203 }
204 DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping);
205
206 static void resume_mapping(struct pci_dev *pdev)
207 {
208 struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
209 int i;
210
211 if (!map)
212 return;
213
214
215 if (!map->is_suspended)
216 goto out;
217 map->is_suspended = 0;
218
219 /* Restore all window configs */
220 for (i = 0; i < STA2X11_NR_FUNCS; i++) {
221 struct sta2x11_ahb_regs *regs = map->regs + i;
222
223 pci_write_config_dword(pdev, AHB_BASE(i), regs->base);
224 pci_write_config_dword(pdev, AHB_PEXLBASE(i), regs->pexlbase);
225 pci_write_config_dword(pdev, AHB_PEXHBASE(i), regs->pexhbase);
226 pci_write_config_dword(pdev, AHB_CRW(i), regs->crw);
227 }
228 out:
229 pci_set_master(pdev); /* Like at boot, enable master on all devices */
230 }
231 DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, resume_mapping);
232
233 #endif /* CONFIG_PM */
234
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