xref: /openbmc/linux/arch/mips/pci/pci-lantiq.c (revision 4f3db074)
1 /*
2  *  This program is free software; you can redistribute it and/or modify it
3  *  under the terms of the GNU General Public License version 2 as published
4  *  by the Free Software Foundation.
5  *
6  *  Copyright (C) 2010 John Crispin <blogic@openwrt.org>
7  */
8 
9 #include <linux/types.h>
10 #include <linux/pci.h>
11 #include <linux/kernel.h>
12 #include <linux/init.h>
13 #include <linux/delay.h>
14 #include <linux/mm.h>
15 #include <linux/vmalloc.h>
16 #include <linux/module.h>
17 #include <linux/clk.h>
18 #include <linux/of_platform.h>
19 #include <linux/of_gpio.h>
20 #include <linux/of_irq.h>
21 #include <linux/of_pci.h>
22 
23 #include <asm/pci.h>
24 #include <asm/gpio.h>
25 #include <asm/addrspace.h>
26 
27 #include <lantiq_soc.h>
28 #include <lantiq_irq.h>
29 
30 #include "pci-lantiq.h"
31 
32 #define PCI_CR_FCI_ADDR_MAP0		0x00C0
33 #define PCI_CR_FCI_ADDR_MAP1		0x00C4
34 #define PCI_CR_FCI_ADDR_MAP2		0x00C8
35 #define PCI_CR_FCI_ADDR_MAP3		0x00CC
36 #define PCI_CR_FCI_ADDR_MAP4		0x00D0
37 #define PCI_CR_FCI_ADDR_MAP5		0x00D4
38 #define PCI_CR_FCI_ADDR_MAP6		0x00D8
39 #define PCI_CR_FCI_ADDR_MAP7		0x00DC
40 #define PCI_CR_CLK_CTRL			0x0000
41 #define PCI_CR_PCI_MOD			0x0030
42 #define PCI_CR_PC_ARB			0x0080
43 #define PCI_CR_FCI_ADDR_MAP11hg		0x00E4
44 #define PCI_CR_BAR11MASK		0x0044
45 #define PCI_CR_BAR12MASK		0x0048
46 #define PCI_CR_BAR13MASK		0x004C
47 #define PCI_CS_BASE_ADDR1		0x0010
48 #define PCI_CR_PCI_ADDR_MAP11		0x0064
49 #define PCI_CR_FCI_BURST_LENGTH		0x00E8
50 #define PCI_CR_PCI_EOI			0x002C
51 #define PCI_CS_STS_CMD			0x0004
52 
53 #define PCI_MASTER0_REQ_MASK_2BITS	8
54 #define PCI_MASTER1_REQ_MASK_2BITS	10
55 #define PCI_MASTER2_REQ_MASK_2BITS	12
56 #define INTERNAL_ARB_ENABLE_BIT		0
57 
58 #define LTQ_CGU_IFCCR		0x0018
59 #define LTQ_CGU_PCICR		0x0034
60 
61 #define ltq_pci_w32(x, y)	ltq_w32((x), ltq_pci_membase + (y))
62 #define ltq_pci_r32(x)		ltq_r32(ltq_pci_membase + (x))
63 
64 #define ltq_pci_cfg_w32(x, y)	ltq_w32((x), ltq_pci_mapped_cfg + (y))
65 #define ltq_pci_cfg_r32(x)	ltq_r32(ltq_pci_mapped_cfg + (x))
66 
67 __iomem void *ltq_pci_mapped_cfg;
68 static __iomem void *ltq_pci_membase;
69 
70 static int reset_gpio;
71 static struct clk *clk_pci, *clk_external;
72 static struct resource pci_io_resource;
73 static struct resource pci_mem_resource;
74 static struct pci_ops pci_ops = {
75 	.read	= ltq_pci_read_config_dword,
76 	.write	= ltq_pci_write_config_dword
77 };
78 
79 static struct pci_controller pci_controller = {
80 	.pci_ops	= &pci_ops,
81 	.mem_resource	= &pci_mem_resource,
82 	.mem_offset	= 0x00000000UL,
83 	.io_resource	= &pci_io_resource,
84 	.io_offset	= 0x00000000UL,
85 };
86 
87 static inline u32 ltq_calc_bar11mask(void)
88 {
89 	u32 mem, bar11mask;
90 
91 	/* BAR11MASK value depends on available memory on system. */
92 	mem = get_num_physpages() * PAGE_SIZE;
93 	bar11mask = (0x0ffffff0 & ~((1 << (fls(mem) - 1)) - 1)) | 8;
94 
95 	return bar11mask;
96 }
97 
98 static int ltq_pci_startup(struct platform_device *pdev)
99 {
100 	struct device_node *node = pdev->dev.of_node;
101 	const __be32 *req_mask, *bus_clk;
102 	u32 temp_buffer;
103 
104 	/* get our clocks */
105 	clk_pci = clk_get(&pdev->dev, NULL);
106 	if (IS_ERR(clk_pci)) {
107 		dev_err(&pdev->dev, "failed to get pci clock\n");
108 		return PTR_ERR(clk_pci);
109 	}
110 
111 	clk_external = clk_get(&pdev->dev, "external");
112 	if (IS_ERR(clk_external)) {
113 		clk_put(clk_pci);
114 		dev_err(&pdev->dev, "failed to get external pci clock\n");
115 		return PTR_ERR(clk_external);
116 	}
117 
118 	/* read the bus speed that we want */
119 	bus_clk = of_get_property(node, "lantiq,bus-clock", NULL);
120 	if (bus_clk)
121 		clk_set_rate(clk_pci, *bus_clk);
122 
123 	/* and enable the clocks */
124 	clk_enable(clk_pci);
125 	if (of_find_property(node, "lantiq,external-clock", NULL))
126 		clk_enable(clk_external);
127 	else
128 		clk_disable(clk_external);
129 
130 	/* setup reset gpio used by pci */
131 	reset_gpio = of_get_named_gpio(node, "gpio-reset", 0);
132 	if (gpio_is_valid(reset_gpio)) {
133 		int ret = devm_gpio_request(&pdev->dev,
134 						reset_gpio, "pci-reset");
135 		if (ret) {
136 			dev_err(&pdev->dev,
137 				"failed to request gpio %d\n", reset_gpio);
138 			return ret;
139 		}
140 		gpio_direction_output(reset_gpio, 1);
141 	}
142 
143 	/* enable auto-switching between PCI and EBU */
144 	ltq_pci_w32(0xa, PCI_CR_CLK_CTRL);
145 
146 	/* busy, i.e. configuration is not done, PCI access has to be retried */
147 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_MOD) & ~(1 << 24), PCI_CR_PCI_MOD);
148 	wmb();
149 	/* BUS Master/IO/MEM access */
150 	ltq_pci_cfg_w32(ltq_pci_cfg_r32(PCI_CS_STS_CMD) | 7, PCI_CS_STS_CMD);
151 
152 	/* enable external 2 PCI masters */
153 	temp_buffer = ltq_pci_r32(PCI_CR_PC_ARB);
154 	/* setup the request mask */
155 	req_mask = of_get_property(node, "req-mask", NULL);
156 	if (req_mask)
157 		temp_buffer &= ~((*req_mask & 0xf) << 16);
158 	else
159 		temp_buffer &= ~0xf0000;
160 	/* enable internal arbiter */
161 	temp_buffer |= (1 << INTERNAL_ARB_ENABLE_BIT);
162 	/* enable internal PCI master reqest */
163 	temp_buffer &= (~(3 << PCI_MASTER0_REQ_MASK_2BITS));
164 
165 	/* enable EBU request */
166 	temp_buffer &= (~(3 << PCI_MASTER1_REQ_MASK_2BITS));
167 
168 	/* enable all external masters request */
169 	temp_buffer &= (~(3 << PCI_MASTER2_REQ_MASK_2BITS));
170 	ltq_pci_w32(temp_buffer, PCI_CR_PC_ARB);
171 	wmb();
172 
173 	/* setup BAR memory regions */
174 	ltq_pci_w32(0x18000000, PCI_CR_FCI_ADDR_MAP0);
175 	ltq_pci_w32(0x18400000, PCI_CR_FCI_ADDR_MAP1);
176 	ltq_pci_w32(0x18800000, PCI_CR_FCI_ADDR_MAP2);
177 	ltq_pci_w32(0x18c00000, PCI_CR_FCI_ADDR_MAP3);
178 	ltq_pci_w32(0x19000000, PCI_CR_FCI_ADDR_MAP4);
179 	ltq_pci_w32(0x19400000, PCI_CR_FCI_ADDR_MAP5);
180 	ltq_pci_w32(0x19800000, PCI_CR_FCI_ADDR_MAP6);
181 	ltq_pci_w32(0x19c00000, PCI_CR_FCI_ADDR_MAP7);
182 	ltq_pci_w32(0x1ae00000, PCI_CR_FCI_ADDR_MAP11hg);
183 	ltq_pci_w32(ltq_calc_bar11mask(), PCI_CR_BAR11MASK);
184 	ltq_pci_w32(0, PCI_CR_PCI_ADDR_MAP11);
185 	ltq_pci_w32(0, PCI_CS_BASE_ADDR1);
186 	/* both TX and RX endian swap are enabled */
187 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_EOI) | 3, PCI_CR_PCI_EOI);
188 	wmb();
189 	ltq_pci_w32(ltq_pci_r32(PCI_CR_BAR12MASK) | 0x80000000,
190 		PCI_CR_BAR12MASK);
191 	ltq_pci_w32(ltq_pci_r32(PCI_CR_BAR13MASK) | 0x80000000,
192 		PCI_CR_BAR13MASK);
193 	/*use 8 dw burst length */
194 	ltq_pci_w32(0x303, PCI_CR_FCI_BURST_LENGTH);
195 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_MOD) | (1 << 24), PCI_CR_PCI_MOD);
196 	wmb();
197 
198 	/* setup irq line */
199 	ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_CON) | 0xc, LTQ_EBU_PCC_CON);
200 	ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_IEN) | 0x10, LTQ_EBU_PCC_IEN);
201 
202 	/* toggle reset pin */
203 	if (gpio_is_valid(reset_gpio)) {
204 		__gpio_set_value(reset_gpio, 0);
205 		wmb();
206 		mdelay(1);
207 		__gpio_set_value(reset_gpio, 1);
208 	}
209 	return 0;
210 }
211 
212 static int ltq_pci_probe(struct platform_device *pdev)
213 {
214 	struct resource *res_cfg, *res_bridge;
215 
216 	pci_clear_flags(PCI_PROBE_ONLY);
217 
218 	res_bridge = platform_get_resource(pdev, IORESOURCE_MEM, 1);
219 	ltq_pci_membase = devm_ioremap_resource(&pdev->dev, res_bridge);
220 	if (IS_ERR(ltq_pci_membase))
221 		return PTR_ERR(ltq_pci_membase);
222 
223 	res_cfg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
224 	ltq_pci_mapped_cfg = devm_ioremap_resource(&pdev->dev, res_cfg);
225 	if (IS_ERR(ltq_pci_mapped_cfg))
226 		return PTR_ERR(ltq_pci_mapped_cfg);
227 
228 	ltq_pci_startup(pdev);
229 
230 	pci_load_of_ranges(&pci_controller, pdev->dev.of_node);
231 	register_pci_controller(&pci_controller);
232 	return 0;
233 }
234 
235 static const struct of_device_id ltq_pci_match[] = {
236 	{ .compatible = "lantiq,pci-xway" },
237 	{},
238 };
239 MODULE_DEVICE_TABLE(of, ltq_pci_match);
240 
241 static struct platform_driver ltq_pci_driver = {
242 	.probe = ltq_pci_probe,
243 	.driver = {
244 		.name = "pci-xway",
245 		.of_match_table = ltq_pci_match,
246 	},
247 };
248 
249 int __init pcibios_init(void)
250 {
251 	int ret = platform_driver_register(&ltq_pci_driver);
252 	if (ret)
253 		pr_info("pci-xway: Error registering platform driver!");
254 	return ret;
255 }
256 
257 arch_initcall(pcibios_init);
258