1/*
2 * arch/x86/pci/sta2x11-fixup.c
3 * glue code for lib/swiotlb.c and DMA translation between STA2x11
4 * AMBA memory mapping and the X86 memory mapping
5 *
6 * ST Microelectronics ConneXt (STA2X11/STA2X10)
7 *
8 * Copyright (c) 2010-2011 Wind River Systems, Inc.
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License version 2 as
12 * published by the Free Software Foundation.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
17 * See the GNU General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this program; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 *
23 */
24
25#include <linux/pci.h>
26#include <linux/pci_ids.h>
27#include <linux/export.h>
28#include <linux/list.h>
29
30#define STA2X11_SWIOTLB_SIZE (4*1024*1024)
31extern int swiotlb_late_init_with_default_size(size_t default_size);
32
33/*
34 * We build a list of bus numbers that are under the ConneXt. The
35 * main bridge hosts 4 busses, which are the 4 endpoints, in order.
36 */
37#define STA2X11_NR_EP		4	/* 0..3 included */
38#define STA2X11_NR_FUNCS	8	/* 0..7 included */
39#define STA2X11_AMBA_SIZE	(512 << 20)
40
41struct sta2x11_ahb_regs { /* saved during suspend */
42	u32 base, pexlbase, pexhbase, crw;
43};
44
45struct sta2x11_mapping {
46	u32 amba_base;
47	int is_suspended;
48	struct sta2x11_ahb_regs regs[STA2X11_NR_FUNCS];
49};
50
51struct sta2x11_instance {
52	struct list_head list;
53	int bus0;
54	struct sta2x11_mapping map[STA2X11_NR_EP];
55};
56
57static LIST_HEAD(sta2x11_instance_list);
58
59/* At probe time, record new instances of this bridge (likely one only) */
60static void sta2x11_new_instance(struct pci_dev *pdev)
61{
62	struct sta2x11_instance *instance;
63
64	instance = kzalloc(sizeof(*instance), GFP_ATOMIC);
65	if (!instance)
66		return;
67	/* This has a subordinate bridge, with 4 more-subordinate ones */
68	instance->bus0 = pdev->subordinate->number + 1;
69
70	if (list_empty(&sta2x11_instance_list)) {
71		int size = STA2X11_SWIOTLB_SIZE;
72		/* First instance: register your own swiotlb area */
73		dev_info(&pdev->dev, "Using SWIOTLB (size %i)\n", size);
74		if (swiotlb_late_init_with_default_size(size))
75			dev_emerg(&pdev->dev, "init swiotlb failed\n");
76	}
77	list_add(&instance->list, &sta2x11_instance_list);
78}
79DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, 0xcc17, sta2x11_new_instance);
80
81/*
82 * Utility functions used in this file from below
83 */
84static struct sta2x11_instance *sta2x11_pdev_to_instance(struct pci_dev *pdev)
85{
86	struct sta2x11_instance *instance;
87	int ep;
88
89	list_for_each_entry(instance, &sta2x11_instance_list, list) {
90		ep = pdev->bus->number - instance->bus0;
91		if (ep >= 0 && ep < STA2X11_NR_EP)
92			return instance;
93	}
94	return NULL;
95}
96
97static int sta2x11_pdev_to_ep(struct pci_dev *pdev)
98{
99	struct sta2x11_instance *instance;
100
101	instance = sta2x11_pdev_to_instance(pdev);
102	if (!instance)
103		return -1;
104
105	return pdev->bus->number - instance->bus0;
106}
107
108static struct sta2x11_mapping *sta2x11_pdev_to_mapping(struct pci_dev *pdev)
109{
110	struct sta2x11_instance *instance;
111	int ep;
112
113	instance = sta2x11_pdev_to_instance(pdev);
114	if (!instance)
115		return NULL;
116	ep = sta2x11_pdev_to_ep(pdev);
117	return instance->map + ep;
118}
119
120/* This is exported, as some devices need to access the MFD registers */
121struct sta2x11_instance *sta2x11_get_instance(struct pci_dev *pdev)
122{
123	return sta2x11_pdev_to_instance(pdev);
124}
125EXPORT_SYMBOL(sta2x11_get_instance);
126
127
128/**
129 * p2a - Translate physical address to STA2x11 AMBA address,
130 *       used for DMA transfers to STA2x11
131 * @p: Physical address
132 * @pdev: PCI device (must be hosted within the connext)
133 */
134static dma_addr_t p2a(dma_addr_t p, struct pci_dev *pdev)
135{
136	struct sta2x11_mapping *map;
137	dma_addr_t a;
138
139	map = sta2x11_pdev_to_mapping(pdev);
140	a = p + map->amba_base;
141	return a;
142}
143
144/**
145 * a2p - Translate STA2x11 AMBA address to physical address
146 *       used for DMA transfers from STA2x11
147 * @a: STA2x11 AMBA address
148 * @pdev: PCI device (must be hosted within the connext)
149 */
150static dma_addr_t a2p(dma_addr_t a, struct pci_dev *pdev)
151{
152	struct sta2x11_mapping *map;
153	dma_addr_t p;
154
155	map = sta2x11_pdev_to_mapping(pdev);
156	p = a - map->amba_base;
157	return p;
158}
159
160/**
161 * sta2x11_swiotlb_alloc_coherent - Allocate swiotlb bounce buffers
162 *     returns virtual address. This is the only "special" function here.
163 * @dev: PCI device
164 * @size: Size of the buffer
165 * @dma_handle: DMA address
166 * @flags: memory flags
167 */
168static void *sta2x11_swiotlb_alloc_coherent(struct device *dev,
169					    size_t size,
170					    dma_addr_t *dma_handle,
171					    gfp_t flags,
172					    struct dma_attrs *attrs)
173{
174	void *vaddr;
175
176	vaddr = x86_swiotlb_alloc_coherent(dev, size, dma_handle, flags, attrs);
177	*dma_handle = p2a(*dma_handle, to_pci_dev(dev));
178	return vaddr;
179}
180
181/* We have our own dma_ops: the same as swiotlb but from alloc (above) */
182static struct dma_map_ops sta2x11_dma_ops = {
183	.alloc = sta2x11_swiotlb_alloc_coherent,
184	.free = x86_swiotlb_free_coherent,
185	.map_page = swiotlb_map_page,
186	.unmap_page = swiotlb_unmap_page,
187	.map_sg = swiotlb_map_sg_attrs,
188	.unmap_sg = swiotlb_unmap_sg_attrs,
189	.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
190	.sync_single_for_device = swiotlb_sync_single_for_device,
191	.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
192	.sync_sg_for_device = swiotlb_sync_sg_for_device,
193	.mapping_error = swiotlb_dma_mapping_error,
194	.dma_supported = NULL, /* FIXME: we should use this instead! */
195};
196
197/* At setup time, we use our own ops if the device is a ConneXt one */
198static void sta2x11_setup_pdev(struct pci_dev *pdev)
199{
200	struct sta2x11_instance *instance = sta2x11_pdev_to_instance(pdev);
201
202	if (!instance) /* either a sta2x11 bridge or another ST device */
203		return;
204	pci_set_consistent_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
205	pci_set_dma_mask(pdev, STA2X11_AMBA_SIZE - 1);
206	pdev->dev.archdata.dma_ops = &sta2x11_dma_ops;
207
208	/* We must enable all devices as master, for audio DMA to work */
209	pci_set_master(pdev);
210}
211DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_setup_pdev);
212
213/*
214 * The following three functions are exported (used in swiotlb: FIXME)
215 */
216/**
217 * dma_capable - Check if device can manage DMA transfers (FIXME: kill it)
218 * @dev: device for a PCI device
219 * @addr: DMA address
220 * @size: DMA size
221 */
222bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
223{
224	struct sta2x11_mapping *map;
225
226	if (dev->archdata.dma_ops != &sta2x11_dma_ops) {
227		if (!dev->dma_mask)
228			return false;
229		return addr + size - 1 <= *dev->dma_mask;
230	}
231
232	map = sta2x11_pdev_to_mapping(to_pci_dev(dev));
233
234	if (!map || (addr < map->amba_base))
235		return false;
236	if (addr + size >= map->amba_base + STA2X11_AMBA_SIZE) {
237		return false;
238	}
239
240	return true;
241}
242
243/**
244 * phys_to_dma - Return the DMA AMBA address used for this STA2x11 device
245 * @dev: device for a PCI device
246 * @paddr: Physical address
247 */
248dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
249{
250	if (dev->archdata.dma_ops != &sta2x11_dma_ops)
251		return paddr;
252	return p2a(paddr, to_pci_dev(dev));
253}
254
255/**
256 * dma_to_phys - Return the physical address used for this STA2x11 DMA address
257 * @dev: device for a PCI device
258 * @daddr: STA2x11 AMBA DMA address
259 */
260phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
261{
262	if (dev->archdata.dma_ops != &sta2x11_dma_ops)
263		return daddr;
264	return a2p(daddr, to_pci_dev(dev));
265}
266
267
268/*
269 * At boot we must set up the mappings for the pcie-to-amba bridge.
270 * It involves device access, and the same happens at suspend/resume time
271 */
272
273#define AHB_MAPB		0xCA4
274#define AHB_CRW(i)		(AHB_MAPB + 0  + (i) * 0x10)
275#define AHB_CRW_SZMASK			0xfffffc00UL
276#define AHB_CRW_ENABLE			(1 << 0)
277#define AHB_CRW_WTYPE_MEM		(2 << 1)
278#define AHB_CRW_ROE			(1UL << 3)	/* Relax Order Ena */
279#define AHB_CRW_NSE			(1UL << 4)	/* No Snoop Enable */
280#define AHB_BASE(i)		(AHB_MAPB + 4  + (i) * 0x10)
281#define AHB_PEXLBASE(i)		(AHB_MAPB + 8  + (i) * 0x10)
282#define AHB_PEXHBASE(i)		(AHB_MAPB + 12 + (i) * 0x10)
283
284/* At probe time, enable mapping for each endpoint, using the pdev */
285static void sta2x11_map_ep(struct pci_dev *pdev)
286{
287	struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
288	int i;
289
290	if (!map)
291		return;
292	pci_read_config_dword(pdev, AHB_BASE(0), &map->amba_base);
293
294	/* Configure AHB mapping */
295	pci_write_config_dword(pdev, AHB_PEXLBASE(0), 0);
296	pci_write_config_dword(pdev, AHB_PEXHBASE(0), 0);
297	pci_write_config_dword(pdev, AHB_CRW(0), STA2X11_AMBA_SIZE |
298			       AHB_CRW_WTYPE_MEM | AHB_CRW_ENABLE);
299
300	/* Disable all the other windows */
301	for (i = 1; i < STA2X11_NR_FUNCS; i++)
302		pci_write_config_dword(pdev, AHB_CRW(i), 0);
303
304	dev_info(&pdev->dev,
305		 "sta2x11: Map EP %i: AMBA address %#8x-%#8x\n",
306		 sta2x11_pdev_to_ep(pdev),  map->amba_base,
307		 map->amba_base + STA2X11_AMBA_SIZE - 1);
308}
309DECLARE_PCI_FIXUP_ENABLE(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, sta2x11_map_ep);
310
311#ifdef CONFIG_PM /* Some register values must be saved and restored */
312
313static void suspend_mapping(struct pci_dev *pdev)
314{
315	struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
316	int i;
317
318	if (!map)
319		return;
320
321	if (map->is_suspended)
322		return;
323	map->is_suspended = 1;
324
325	/* Save all window configs */
326	for (i = 0; i < STA2X11_NR_FUNCS; i++) {
327		struct sta2x11_ahb_regs *regs = map->regs + i;
328
329		pci_read_config_dword(pdev, AHB_BASE(i), &regs->base);
330		pci_read_config_dword(pdev, AHB_PEXLBASE(i), &regs->pexlbase);
331		pci_read_config_dword(pdev, AHB_PEXHBASE(i), &regs->pexhbase);
332		pci_read_config_dword(pdev, AHB_CRW(i), &regs->crw);
333	}
334}
335DECLARE_PCI_FIXUP_SUSPEND(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, suspend_mapping);
336
337static void resume_mapping(struct pci_dev *pdev)
338{
339	struct sta2x11_mapping *map = sta2x11_pdev_to_mapping(pdev);
340	int i;
341
342	if (!map)
343		return;
344
345
346	if (!map->is_suspended)
347		goto out;
348	map->is_suspended = 0;
349
350	/* Restore all window configs */
351	for (i = 0; i < STA2X11_NR_FUNCS; i++) {
352		struct sta2x11_ahb_regs *regs = map->regs + i;
353
354		pci_write_config_dword(pdev, AHB_BASE(i), regs->base);
355		pci_write_config_dword(pdev, AHB_PEXLBASE(i), regs->pexlbase);
356		pci_write_config_dword(pdev, AHB_PEXHBASE(i), regs->pexhbase);
357		pci_write_config_dword(pdev, AHB_CRW(i), regs->crw);
358	}
359out:
360	pci_set_master(pdev); /* Like at boot, enable master on all devices */
361}
362DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_STMICRO, PCI_ANY_ID, resume_mapping);
363
364#endif /* CONFIG_PM */
365