1 /*
2 * pci.c -- PCI bus support for ColdFire processors
3 *
4 * (C) Copyright 2012, Greg Ungerer <gerg@uclinux.com>
5 *
6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file COPYING in the main directory of this archive
8 * for more details.
9 */
10
11 #include <linux/types.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/kernel.h>
15 #include <linux/interrupt.h>
16 #include <linux/irq.h>
17 #include <linux/io.h>
18 #include <linux/pci.h>
19 #include <linux/delay.h>
20 #include <asm/coldfire.h>
21 #include <asm/mcfsim.h>
22 #include <asm/m54xxpci.h>
23
24 /*
25 * Memory and IO mappings. We use a 1:1 mapping for local host memory to
26 * PCI bus memory (no reason not to really). IO space is mapped in its own
27 * separate address region. The device configuration space is mapped over
28 * the IO map space when we enable it in the PCICAR register.
29 */
30 static struct pci_bus *rootbus;
31 static unsigned long iospace;
32
33 /*
34 * We need to be careful probing on bus 0 (directly connected to host
35 * bridge). We should only access the well defined possible devices in
36 * use, ignore aliases and the like.
37 */
38 static unsigned char mcf_host_slot2sid[32] = {
39 0, 0, 0, 0, 0, 0, 0, 0,
40 0, 0, 0, 0, 0, 0, 0, 0,
41 0, 1, 2, 0, 3, 4, 0, 0,
42 0, 0, 0, 0, 0, 0, 0, 0,
43 };
44
45 static unsigned char mcf_host_irq[] = {
46 0, 69, 69, 71, 71,
47 };
48
49 /*
50 * Configuration space access functions. Configuration space access is
51 * through the IO mapping window, enabling it via the PCICAR register.
52 */
53 static unsigned long mcf_mk_pcicar(int bus, unsigned int devfn, int where)
54 {
55 return (bus << PCICAR_BUSN) | (devfn << PCICAR_DEVFNN) | (where & 0xfc);
56 }
57
58 static int mcf_pci_readconfig(struct pci_bus *bus, unsigned int devfn,
59 int where, int size, u32 *value)
60 {
61 unsigned long addr;
62
63 *value = 0xffffffff;
64
65 if (bus->number == 0) {
66 if (mcf_host_slot2sid[PCI_SLOT(devfn)] == 0)
67 return PCIBIOS_SUCCESSFUL;
68 }
69
70 addr = mcf_mk_pcicar(bus->number, devfn, where);
71 __raw_writel(PCICAR_E | addr, PCICAR);
72 __raw_readl(PCICAR);
73 addr = iospace + (where & 0x3);
74
75 switch (size) {
76 case 1:
77 *value = __raw_readb(addr);
78 break;
79 case 2:
80 *value = le16_to_cpu(__raw_readw(addr));
81 break;
82 default:
83 *value = le32_to_cpu(__raw_readl(addr));
84 break;
85 }
86
87 __raw_writel(0, PCICAR);
88 __raw_readl(PCICAR);
89 return PCIBIOS_SUCCESSFUL;
90 }
91
92 static int mcf_pci_writeconfig(struct pci_bus *bus, unsigned int devfn,
93 int where, int size, u32 value)
94 {
95 unsigned long addr;
96
97 if (bus->number == 0) {
98 if (mcf_host_slot2sid[PCI_SLOT(devfn)] == 0)
99 return PCIBIOS_SUCCESSFUL;
100 }
101
102 addr = mcf_mk_pcicar(bus->number, devfn, where);
103 __raw_writel(PCICAR_E | addr, PCICAR);
104 __raw_readl(PCICAR);
105 addr = iospace + (where & 0x3);
106
107 switch (size) {
108 case 1:
109 __raw_writeb(value, addr);
110 break;
111 case 2:
112 __raw_writew(cpu_to_le16(value), addr);
113 break;
114 default:
115 __raw_writel(cpu_to_le32(value), addr);
116 break;
117 }
118
119 __raw_writel(0, PCICAR);
120 __raw_readl(PCICAR);
121 return PCIBIOS_SUCCESSFUL;
122 }
123
124 static struct pci_ops mcf_pci_ops = {
125 .read = mcf_pci_readconfig,
126 .write = mcf_pci_writeconfig,
127 };
128
129 /*
130 * Initialize the PCI bus registers, and scan the bus.
131 */
132 static struct resource mcf_pci_mem = {
133 .name = "PCI Memory space",
134 .start = PCI_MEM_PA,
135 .end = PCI_MEM_PA + PCI_MEM_SIZE - 1,
136 .flags = IORESOURCE_MEM,
137 };
138
139 static struct resource mcf_pci_io = {
140 .name = "PCI IO space",
141 .start = 0x400,
142 .end = 0x10000 - 1,
143 .flags = IORESOURCE_IO,
144 };
145
146 static struct resource busn_resource = {
147 .name = "PCI busn",
148 .start = 0,
149 .end = 255,
150 .flags = IORESOURCE_BUS,
151 };
152
153 /*
154 * Interrupt mapping and setting.
155 */
156 static int mcf_pci_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)
157 {
158 int sid;
159
160 sid = mcf_host_slot2sid[slot];
161 if (sid)
162 return mcf_host_irq[sid];
163 return 0;
164 }
165
166 static int __init mcf_pci_init(void)
167 {
168 struct pci_host_bridge *bridge;
169 int ret;
170
171 bridge = pci_alloc_host_bridge(0);
172 if (!bridge)
173 return -ENOMEM;
174
175 pr_info("ColdFire: PCI bus initialization...\n");
176
177 /* Reset the external PCI bus */
178 __raw_writel(PCIGSCR_RESET, PCIGSCR);
179 __raw_writel(0, PCITCR);
180
181 request_resource(&iomem_resource, &mcf_pci_mem);
182 request_resource(&iomem_resource, &mcf_pci_io);
183
184 /* Configure PCI arbiter */
185 __raw_writel(PACR_INTMPRI | PACR_INTMINTE | PACR_EXTMPRI(0x1f) |
186 PACR_EXTMINTE(0x1f), PACR);
187
188 /* Set required multi-function pins for PCI bus use */
189 __raw_writew(0x3ff, MCFGPIO_PAR_PCIBG);
190 __raw_writew(0x3ff, MCFGPIO_PAR_PCIBR);
191
192 /* Set up config space for local host bus controller */
193 __raw_writel(PCI_COMMAND_MEMORY | PCI_COMMAND_MASTER |
194 PCI_COMMAND_INVALIDATE, PCISCR);
195 __raw_writel(PCICR1_LT(32) | PCICR1_CL(8), PCICR1);
196 __raw_writel(0, PCICR2);
197
198 /*
199 * Set up the initiator windows for memory and IO mapping.
200 * These give the CPU bus access onto the PCI bus. One for each of
201 * PCI memory and IO address spaces.
202 */
203 __raw_writel(WXBTAR(PCI_MEM_PA, PCI_MEM_BA, PCI_MEM_SIZE),
204 PCIIW0BTAR);
205 __raw_writel(WXBTAR(PCI_IO_PA, PCI_IO_BA, PCI_IO_SIZE),
206 PCIIW1BTAR);
207 __raw_writel(PCIIWCR_W0_MEM /*| PCIIWCR_W0_MRDL*/ | PCIIWCR_W0_E |
208 PCIIWCR_W1_IO | PCIIWCR_W1_E, PCIIWCR);
209
210 /*
211 * Set up the target windows for access from the PCI bus back to the
212 * CPU bus. All we need is access to system RAM (for mastering).
213 */
214 __raw_writel(CONFIG_RAMBASE, PCIBAR1);
215 __raw_writel(CONFIG_RAMBASE | PCITBATR1_E, PCITBATR1);
216
217 /* Keep a virtual mapping to IO/config space active */
218 iospace = (unsigned long) ioremap(PCI_IO_PA, PCI_IO_SIZE);
219 if (iospace == 0) {
220 pci_free_host_bridge(bridge);
221 return -ENODEV;
222 }
223 pr_info("Coldfire: PCI IO/config window mapped to 0x%x\n",
224 (u32) iospace);
225
226 /* Turn of PCI reset, and wait for devices to settle */
227 __raw_writel(0, PCIGSCR);
228 set_current_state(TASK_UNINTERRUPTIBLE);
229 schedule_timeout(msecs_to_jiffies(200));
230
231
232 pci_add_resource(&bridge->windows, &ioport_resource);
233 pci_add_resource(&bridge->windows, &iomem_resource);
234 pci_add_resource(&bridge->windows, &busn_resource);
235 bridge->dev.parent = NULL;
236 bridge->sysdata = NULL;
237 bridge->busnr = 0;
238 bridge->ops = &mcf_pci_ops;
239 bridge->swizzle_irq = pci_common_swizzle;
240 bridge->map_irq = mcf_pci_map_irq;
241
242 ret = pci_scan_root_bus_bridge(bridge);
243 if (ret) {
244 pci_free_host_bridge(bridge);
245 return ret;
246 }
247
248 rootbus = bridge->bus;
249
250 rootbus->resource[0] = &mcf_pci_io;
251 rootbus->resource[1] = &mcf_pci_mem;
252
253 pci_bus_size_bridges(rootbus);
254 pci_bus_assign_resources(rootbus);
255 pci_bus_add_devices(rootbus);
256 return 0;
257 }
258
259 subsys_initcall(mcf_pci_init);
260
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