xref: /openbmc/linux/arch/mips/pci/pci-lantiq.c (revision eb3fcf00)
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/addrspace.h>
24 
25 #include <lantiq_soc.h>
26 #include <lantiq_irq.h>
27 
28 #include "pci-lantiq.h"
29 
30 #define PCI_CR_FCI_ADDR_MAP0		0x00C0
31 #define PCI_CR_FCI_ADDR_MAP1		0x00C4
32 #define PCI_CR_FCI_ADDR_MAP2		0x00C8
33 #define PCI_CR_FCI_ADDR_MAP3		0x00CC
34 #define PCI_CR_FCI_ADDR_MAP4		0x00D0
35 #define PCI_CR_FCI_ADDR_MAP5		0x00D4
36 #define PCI_CR_FCI_ADDR_MAP6		0x00D8
37 #define PCI_CR_FCI_ADDR_MAP7		0x00DC
38 #define PCI_CR_CLK_CTRL			0x0000
39 #define PCI_CR_PCI_MOD			0x0030
40 #define PCI_CR_PC_ARB			0x0080
41 #define PCI_CR_FCI_ADDR_MAP11hg		0x00E4
42 #define PCI_CR_BAR11MASK		0x0044
43 #define PCI_CR_BAR12MASK		0x0048
44 #define PCI_CR_BAR13MASK		0x004C
45 #define PCI_CS_BASE_ADDR1		0x0010
46 #define PCI_CR_PCI_ADDR_MAP11		0x0064
47 #define PCI_CR_FCI_BURST_LENGTH		0x00E8
48 #define PCI_CR_PCI_EOI			0x002C
49 #define PCI_CS_STS_CMD			0x0004
50 
51 #define PCI_MASTER0_REQ_MASK_2BITS	8
52 #define PCI_MASTER1_REQ_MASK_2BITS	10
53 #define PCI_MASTER2_REQ_MASK_2BITS	12
54 #define INTERNAL_ARB_ENABLE_BIT		0
55 
56 #define LTQ_CGU_IFCCR		0x0018
57 #define LTQ_CGU_PCICR		0x0034
58 
59 #define ltq_pci_w32(x, y)	ltq_w32((x), ltq_pci_membase + (y))
60 #define ltq_pci_r32(x)		ltq_r32(ltq_pci_membase + (x))
61 
62 #define ltq_pci_cfg_w32(x, y)	ltq_w32((x), ltq_pci_mapped_cfg + (y))
63 #define ltq_pci_cfg_r32(x)	ltq_r32(ltq_pci_mapped_cfg + (x))
64 
65 __iomem void *ltq_pci_mapped_cfg;
66 static __iomem void *ltq_pci_membase;
67 
68 static int reset_gpio;
69 static struct clk *clk_pci, *clk_external;
70 static struct resource pci_io_resource;
71 static struct resource pci_mem_resource;
72 static struct pci_ops pci_ops = {
73 	.read	= ltq_pci_read_config_dword,
74 	.write	= ltq_pci_write_config_dword
75 };
76 
77 static struct pci_controller pci_controller = {
78 	.pci_ops	= &pci_ops,
79 	.mem_resource	= &pci_mem_resource,
80 	.mem_offset	= 0x00000000UL,
81 	.io_resource	= &pci_io_resource,
82 	.io_offset	= 0x00000000UL,
83 };
84 
85 static inline u32 ltq_calc_bar11mask(void)
86 {
87 	u32 mem, bar11mask;
88 
89 	/* BAR11MASK value depends on available memory on system. */
90 	mem = get_num_physpages() * PAGE_SIZE;
91 	bar11mask = (0x0ffffff0 & ~((1 << (fls(mem) - 1)) - 1)) | 8;
92 
93 	return bar11mask;
94 }
95 
96 static int ltq_pci_startup(struct platform_device *pdev)
97 {
98 	struct device_node *node = pdev->dev.of_node;
99 	const __be32 *req_mask, *bus_clk;
100 	u32 temp_buffer;
101 
102 	/* get our clocks */
103 	clk_pci = clk_get(&pdev->dev, NULL);
104 	if (IS_ERR(clk_pci)) {
105 		dev_err(&pdev->dev, "failed to get pci clock\n");
106 		return PTR_ERR(clk_pci);
107 	}
108 
109 	clk_external = clk_get(&pdev->dev, "external");
110 	if (IS_ERR(clk_external)) {
111 		clk_put(clk_pci);
112 		dev_err(&pdev->dev, "failed to get external pci clock\n");
113 		return PTR_ERR(clk_external);
114 	}
115 
116 	/* read the bus speed that we want */
117 	bus_clk = of_get_property(node, "lantiq,bus-clock", NULL);
118 	if (bus_clk)
119 		clk_set_rate(clk_pci, *bus_clk);
120 
121 	/* and enable the clocks */
122 	clk_enable(clk_pci);
123 	if (of_find_property(node, "lantiq,external-clock", NULL))
124 		clk_enable(clk_external);
125 	else
126 		clk_disable(clk_external);
127 
128 	/* setup reset gpio used by pci */
129 	reset_gpio = of_get_named_gpio(node, "gpio-reset", 0);
130 	if (gpio_is_valid(reset_gpio)) {
131 		int ret = devm_gpio_request(&pdev->dev,
132 						reset_gpio, "pci-reset");
133 		if (ret) {
134 			dev_err(&pdev->dev,
135 				"failed to request gpio %d\n", reset_gpio);
136 			return ret;
137 		}
138 		gpio_direction_output(reset_gpio, 1);
139 	}
140 
141 	/* enable auto-switching between PCI and EBU */
142 	ltq_pci_w32(0xa, PCI_CR_CLK_CTRL);
143 
144 	/* busy, i.e. configuration is not done, PCI access has to be retried */
145 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_MOD) & ~(1 << 24), PCI_CR_PCI_MOD);
146 	wmb();
147 	/* BUS Master/IO/MEM access */
148 	ltq_pci_cfg_w32(ltq_pci_cfg_r32(PCI_CS_STS_CMD) | 7, PCI_CS_STS_CMD);
149 
150 	/* enable external 2 PCI masters */
151 	temp_buffer = ltq_pci_r32(PCI_CR_PC_ARB);
152 	/* setup the request mask */
153 	req_mask = of_get_property(node, "req-mask", NULL);
154 	if (req_mask)
155 		temp_buffer &= ~((*req_mask & 0xf) << 16);
156 	else
157 		temp_buffer &= ~0xf0000;
158 	/* enable internal arbiter */
159 	temp_buffer |= (1 << INTERNAL_ARB_ENABLE_BIT);
160 	/* enable internal PCI master reqest */
161 	temp_buffer &= (~(3 << PCI_MASTER0_REQ_MASK_2BITS));
162 
163 	/* enable EBU request */
164 	temp_buffer &= (~(3 << PCI_MASTER1_REQ_MASK_2BITS));
165 
166 	/* enable all external masters request */
167 	temp_buffer &= (~(3 << PCI_MASTER2_REQ_MASK_2BITS));
168 	ltq_pci_w32(temp_buffer, PCI_CR_PC_ARB);
169 	wmb();
170 
171 	/* setup BAR memory regions */
172 	ltq_pci_w32(0x18000000, PCI_CR_FCI_ADDR_MAP0);
173 	ltq_pci_w32(0x18400000, PCI_CR_FCI_ADDR_MAP1);
174 	ltq_pci_w32(0x18800000, PCI_CR_FCI_ADDR_MAP2);
175 	ltq_pci_w32(0x18c00000, PCI_CR_FCI_ADDR_MAP3);
176 	ltq_pci_w32(0x19000000, PCI_CR_FCI_ADDR_MAP4);
177 	ltq_pci_w32(0x19400000, PCI_CR_FCI_ADDR_MAP5);
178 	ltq_pci_w32(0x19800000, PCI_CR_FCI_ADDR_MAP6);
179 	ltq_pci_w32(0x19c00000, PCI_CR_FCI_ADDR_MAP7);
180 	ltq_pci_w32(0x1ae00000, PCI_CR_FCI_ADDR_MAP11hg);
181 	ltq_pci_w32(ltq_calc_bar11mask(), PCI_CR_BAR11MASK);
182 	ltq_pci_w32(0, PCI_CR_PCI_ADDR_MAP11);
183 	ltq_pci_w32(0, PCI_CS_BASE_ADDR1);
184 	/* both TX and RX endian swap are enabled */
185 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_EOI) | 3, PCI_CR_PCI_EOI);
186 	wmb();
187 	ltq_pci_w32(ltq_pci_r32(PCI_CR_BAR12MASK) | 0x80000000,
188 		PCI_CR_BAR12MASK);
189 	ltq_pci_w32(ltq_pci_r32(PCI_CR_BAR13MASK) | 0x80000000,
190 		PCI_CR_BAR13MASK);
191 	/*use 8 dw burst length */
192 	ltq_pci_w32(0x303, PCI_CR_FCI_BURST_LENGTH);
193 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_MOD) | (1 << 24), PCI_CR_PCI_MOD);
194 	wmb();
195 
196 	/* setup irq line */
197 	ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_CON) | 0xc, LTQ_EBU_PCC_CON);
198 	ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_IEN) | 0x10, LTQ_EBU_PCC_IEN);
199 
200 	/* toggle reset pin */
201 	if (gpio_is_valid(reset_gpio)) {
202 		__gpio_set_value(reset_gpio, 0);
203 		wmb();
204 		mdelay(1);
205 		__gpio_set_value(reset_gpio, 1);
206 	}
207 	return 0;
208 }
209 
210 static int ltq_pci_probe(struct platform_device *pdev)
211 {
212 	struct resource *res_cfg, *res_bridge;
213 
214 	pci_clear_flags(PCI_PROBE_ONLY);
215 
216 	res_bridge = platform_get_resource(pdev, IORESOURCE_MEM, 1);
217 	ltq_pci_membase = devm_ioremap_resource(&pdev->dev, res_bridge);
218 	if (IS_ERR(ltq_pci_membase))
219 		return PTR_ERR(ltq_pci_membase);
220 
221 	res_cfg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
222 	ltq_pci_mapped_cfg = devm_ioremap_resource(&pdev->dev, res_cfg);
223 	if (IS_ERR(ltq_pci_mapped_cfg))
224 		return PTR_ERR(ltq_pci_mapped_cfg);
225 
226 	ltq_pci_startup(pdev);
227 
228 	pci_load_of_ranges(&pci_controller, pdev->dev.of_node);
229 	register_pci_controller(&pci_controller);
230 	return 0;
231 }
232 
233 static const struct of_device_id ltq_pci_match[] = {
234 	{ .compatible = "lantiq,pci-xway" },
235 	{},
236 };
237 MODULE_DEVICE_TABLE(of, ltq_pci_match);
238 
239 static struct platform_driver ltq_pci_driver = {
240 	.probe = ltq_pci_probe,
241 	.driver = {
242 		.name = "pci-xway",
243 		.of_match_table = ltq_pci_match,
244 	},
245 };
246 
247 int __init pcibios_init(void)
248 {
249 	int ret = platform_driver_register(&ltq_pci_driver);
250 	if (ret)
251 		pr_info("pci-xway: Error registering platform driver!");
252 	return ret;
253 }
254 
255 arch_initcall(pcibios_init);
256