xref: /openbmc/linux/arch/mips/pci/pci-lantiq.c (revision e2c75e76)
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 <john@phrozen.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/clk.h>
17 #include <linux/of_platform.h>
18 #include <linux/of_gpio.h>
19 #include <linux/of_irq.h>
20 #include <linux/of_pci.h>
21 
22 #include <asm/addrspace.h>
23 
24 #include <lantiq_soc.h>
25 #include <lantiq_irq.h>
26 
27 #include "pci-lantiq.h"
28 
29 #define PCI_CR_FCI_ADDR_MAP0		0x00C0
30 #define PCI_CR_FCI_ADDR_MAP1		0x00C4
31 #define PCI_CR_FCI_ADDR_MAP2		0x00C8
32 #define PCI_CR_FCI_ADDR_MAP3		0x00CC
33 #define PCI_CR_FCI_ADDR_MAP4		0x00D0
34 #define PCI_CR_FCI_ADDR_MAP5		0x00D4
35 #define PCI_CR_FCI_ADDR_MAP6		0x00D8
36 #define PCI_CR_FCI_ADDR_MAP7		0x00DC
37 #define PCI_CR_CLK_CTRL			0x0000
38 #define PCI_CR_PCI_MOD			0x0030
39 #define PCI_CR_PC_ARB			0x0080
40 #define PCI_CR_FCI_ADDR_MAP11hg		0x00E4
41 #define PCI_CR_BAR11MASK		0x0044
42 #define PCI_CR_BAR12MASK		0x0048
43 #define PCI_CR_BAR13MASK		0x004C
44 #define PCI_CS_BASE_ADDR1		0x0010
45 #define PCI_CR_PCI_ADDR_MAP11		0x0064
46 #define PCI_CR_FCI_BURST_LENGTH		0x00E8
47 #define PCI_CR_PCI_EOI			0x002C
48 #define PCI_CS_STS_CMD			0x0004
49 
50 #define PCI_MASTER0_REQ_MASK_2BITS	8
51 #define PCI_MASTER1_REQ_MASK_2BITS	10
52 #define PCI_MASTER2_REQ_MASK_2BITS	12
53 #define INTERNAL_ARB_ENABLE_BIT		0
54 
55 #define LTQ_CGU_IFCCR		0x0018
56 #define LTQ_CGU_PCICR		0x0034
57 
58 #define ltq_pci_w32(x, y)	ltq_w32((x), ltq_pci_membase + (y))
59 #define ltq_pci_r32(x)		ltq_r32(ltq_pci_membase + (x))
60 
61 #define ltq_pci_cfg_w32(x, y)	ltq_w32((x), ltq_pci_mapped_cfg + (y))
62 #define ltq_pci_cfg_r32(x)	ltq_r32(ltq_pci_mapped_cfg + (x))
63 
64 __iomem void *ltq_pci_mapped_cfg;
65 static __iomem void *ltq_pci_membase;
66 
67 static int reset_gpio;
68 static struct clk *clk_pci, *clk_external;
69 static struct resource pci_io_resource;
70 static struct resource pci_mem_resource;
71 static struct pci_ops pci_ops = {
72 	.read	= ltq_pci_read_config_dword,
73 	.write	= ltq_pci_write_config_dword
74 };
75 
76 static struct pci_controller pci_controller = {
77 	.pci_ops	= &pci_ops,
78 	.mem_resource	= &pci_mem_resource,
79 	.mem_offset	= 0x00000000UL,
80 	.io_resource	= &pci_io_resource,
81 	.io_offset	= 0x00000000UL,
82 };
83 
84 static inline u32 ltq_calc_bar11mask(void)
85 {
86 	u32 mem, bar11mask;
87 
88 	/* BAR11MASK value depends on available memory on system. */
89 	mem = get_num_physpages() * PAGE_SIZE;
90 	bar11mask = (0x0ffffff0 & ~((1 << (fls(mem) - 1)) - 1)) | 8;
91 
92 	return bar11mask;
93 }
94 
95 static int ltq_pci_startup(struct platform_device *pdev)
96 {
97 	struct device_node *node = pdev->dev.of_node;
98 	const __be32 *req_mask, *bus_clk;
99 	u32 temp_buffer;
100 
101 	/* get our clocks */
102 	clk_pci = clk_get(&pdev->dev, NULL);
103 	if (IS_ERR(clk_pci)) {
104 		dev_err(&pdev->dev, "failed to get pci clock\n");
105 		return PTR_ERR(clk_pci);
106 	}
107 
108 	clk_external = clk_get(&pdev->dev, "external");
109 	if (IS_ERR(clk_external)) {
110 		clk_put(clk_pci);
111 		dev_err(&pdev->dev, "failed to get external pci clock\n");
112 		return PTR_ERR(clk_external);
113 	}
114 
115 	/* read the bus speed that we want */
116 	bus_clk = of_get_property(node, "lantiq,bus-clock", NULL);
117 	if (bus_clk)
118 		clk_set_rate(clk_pci, *bus_clk);
119 
120 	/* and enable the clocks */
121 	clk_enable(clk_pci);
122 	if (of_find_property(node, "lantiq,external-clock", NULL))
123 		clk_enable(clk_external);
124 	else
125 		clk_disable(clk_external);
126 
127 	/* setup reset gpio used by pci */
128 	reset_gpio = of_get_named_gpio(node, "gpio-reset", 0);
129 	if (gpio_is_valid(reset_gpio)) {
130 		int ret = devm_gpio_request(&pdev->dev,
131 						reset_gpio, "pci-reset");
132 		if (ret) {
133 			dev_err(&pdev->dev,
134 				"failed to request gpio %d\n", reset_gpio);
135 			return ret;
136 		}
137 		gpio_direction_output(reset_gpio, 1);
138 	}
139 
140 	/* enable auto-switching between PCI and EBU */
141 	ltq_pci_w32(0xa, PCI_CR_CLK_CTRL);
142 
143 	/* busy, i.e. configuration is not done, PCI access has to be retried */
144 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_MOD) & ~(1 << 24), PCI_CR_PCI_MOD);
145 	wmb();
146 	/* BUS Master/IO/MEM access */
147 	ltq_pci_cfg_w32(ltq_pci_cfg_r32(PCI_CS_STS_CMD) | 7, PCI_CS_STS_CMD);
148 
149 	/* enable external 2 PCI masters */
150 	temp_buffer = ltq_pci_r32(PCI_CR_PC_ARB);
151 	/* setup the request mask */
152 	req_mask = of_get_property(node, "req-mask", NULL);
153 	if (req_mask)
154 		temp_buffer &= ~((*req_mask & 0xf) << 16);
155 	else
156 		temp_buffer &= ~0xf0000;
157 	/* enable internal arbiter */
158 	temp_buffer |= (1 << INTERNAL_ARB_ENABLE_BIT);
159 	/* enable internal PCI master reqest */
160 	temp_buffer &= (~(3 << PCI_MASTER0_REQ_MASK_2BITS));
161 
162 	/* enable EBU request */
163 	temp_buffer &= (~(3 << PCI_MASTER1_REQ_MASK_2BITS));
164 
165 	/* enable all external masters request */
166 	temp_buffer &= (~(3 << PCI_MASTER2_REQ_MASK_2BITS));
167 	ltq_pci_w32(temp_buffer, PCI_CR_PC_ARB);
168 	wmb();
169 
170 	/* setup BAR memory regions */
171 	ltq_pci_w32(0x18000000, PCI_CR_FCI_ADDR_MAP0);
172 	ltq_pci_w32(0x18400000, PCI_CR_FCI_ADDR_MAP1);
173 	ltq_pci_w32(0x18800000, PCI_CR_FCI_ADDR_MAP2);
174 	ltq_pci_w32(0x18c00000, PCI_CR_FCI_ADDR_MAP3);
175 	ltq_pci_w32(0x19000000, PCI_CR_FCI_ADDR_MAP4);
176 	ltq_pci_w32(0x19400000, PCI_CR_FCI_ADDR_MAP5);
177 	ltq_pci_w32(0x19800000, PCI_CR_FCI_ADDR_MAP6);
178 	ltq_pci_w32(0x19c00000, PCI_CR_FCI_ADDR_MAP7);
179 	ltq_pci_w32(0x1ae00000, PCI_CR_FCI_ADDR_MAP11hg);
180 	ltq_pci_w32(ltq_calc_bar11mask(), PCI_CR_BAR11MASK);
181 	ltq_pci_w32(0, PCI_CR_PCI_ADDR_MAP11);
182 	ltq_pci_w32(0, PCI_CS_BASE_ADDR1);
183 	/* both TX and RX endian swap are enabled */
184 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_EOI) | 3, PCI_CR_PCI_EOI);
185 	wmb();
186 	ltq_pci_w32(ltq_pci_r32(PCI_CR_BAR12MASK) | 0x80000000,
187 		PCI_CR_BAR12MASK);
188 	ltq_pci_w32(ltq_pci_r32(PCI_CR_BAR13MASK) | 0x80000000,
189 		PCI_CR_BAR13MASK);
190 	/*use 8 dw burst length */
191 	ltq_pci_w32(0x303, PCI_CR_FCI_BURST_LENGTH);
192 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_MOD) | (1 << 24), PCI_CR_PCI_MOD);
193 	wmb();
194 
195 	/* setup irq line */
196 	ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_CON) | 0xc, LTQ_EBU_PCC_CON);
197 	ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_IEN) | 0x10, LTQ_EBU_PCC_IEN);
198 
199 	/* toggle reset pin */
200 	if (gpio_is_valid(reset_gpio)) {
201 		__gpio_set_value(reset_gpio, 0);
202 		wmb();
203 		mdelay(1);
204 		__gpio_set_value(reset_gpio, 1);
205 	}
206 	return 0;
207 }
208 
209 static int ltq_pci_probe(struct platform_device *pdev)
210 {
211 	struct resource *res_cfg, *res_bridge;
212 
213 	pci_clear_flags(PCI_PROBE_ONLY);
214 
215 	res_bridge = platform_get_resource(pdev, IORESOURCE_MEM, 1);
216 	ltq_pci_membase = devm_ioremap_resource(&pdev->dev, res_bridge);
217 	if (IS_ERR(ltq_pci_membase))
218 		return PTR_ERR(ltq_pci_membase);
219 
220 	res_cfg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
221 	ltq_pci_mapped_cfg = devm_ioremap_resource(&pdev->dev, res_cfg);
222 	if (IS_ERR(ltq_pci_mapped_cfg))
223 		return PTR_ERR(ltq_pci_mapped_cfg);
224 
225 	ltq_pci_startup(pdev);
226 
227 	pci_load_of_ranges(&pci_controller, pdev->dev.of_node);
228 	register_pci_controller(&pci_controller);
229 	return 0;
230 }
231 
232 static const struct of_device_id ltq_pci_match[] = {
233 	{ .compatible = "lantiq,pci-xway" },
234 	{},
235 };
236 
237 static struct platform_driver ltq_pci_driver = {
238 	.probe = ltq_pci_probe,
239 	.driver = {
240 		.name = "pci-xway",
241 		.of_match_table = ltq_pci_match,
242 	},
243 };
244 
245 int __init pcibios_init(void)
246 {
247 	int ret = platform_driver_register(&ltq_pci_driver);
248 	if (ret)
249 		pr_info("pci-xway: Error registering platform driver!");
250 	return ret;
251 }
252 
253 arch_initcall(pcibios_init);
254