xref: /openbmc/linux/arch/mips/pci/pci-lantiq.c (revision 6189f1b0)
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/gpio.h>
24 #include <asm/addrspace.h>
25 
26 #include <lantiq_soc.h>
27 #include <lantiq_irq.h>
28 
29 #include "pci-lantiq.h"
30 
31 #define PCI_CR_FCI_ADDR_MAP0		0x00C0
32 #define PCI_CR_FCI_ADDR_MAP1		0x00C4
33 #define PCI_CR_FCI_ADDR_MAP2		0x00C8
34 #define PCI_CR_FCI_ADDR_MAP3		0x00CC
35 #define PCI_CR_FCI_ADDR_MAP4		0x00D0
36 #define PCI_CR_FCI_ADDR_MAP5		0x00D4
37 #define PCI_CR_FCI_ADDR_MAP6		0x00D8
38 #define PCI_CR_FCI_ADDR_MAP7		0x00DC
39 #define PCI_CR_CLK_CTRL			0x0000
40 #define PCI_CR_PCI_MOD			0x0030
41 #define PCI_CR_PC_ARB			0x0080
42 #define PCI_CR_FCI_ADDR_MAP11hg		0x00E4
43 #define PCI_CR_BAR11MASK		0x0044
44 #define PCI_CR_BAR12MASK		0x0048
45 #define PCI_CR_BAR13MASK		0x004C
46 #define PCI_CS_BASE_ADDR1		0x0010
47 #define PCI_CR_PCI_ADDR_MAP11		0x0064
48 #define PCI_CR_FCI_BURST_LENGTH		0x00E8
49 #define PCI_CR_PCI_EOI			0x002C
50 #define PCI_CS_STS_CMD			0x0004
51 
52 #define PCI_MASTER0_REQ_MASK_2BITS	8
53 #define PCI_MASTER1_REQ_MASK_2BITS	10
54 #define PCI_MASTER2_REQ_MASK_2BITS	12
55 #define INTERNAL_ARB_ENABLE_BIT		0
56 
57 #define LTQ_CGU_IFCCR		0x0018
58 #define LTQ_CGU_PCICR		0x0034
59 
60 #define ltq_pci_w32(x, y)	ltq_w32((x), ltq_pci_membase + (y))
61 #define ltq_pci_r32(x)		ltq_r32(ltq_pci_membase + (x))
62 
63 #define ltq_pci_cfg_w32(x, y)	ltq_w32((x), ltq_pci_mapped_cfg + (y))
64 #define ltq_pci_cfg_r32(x)	ltq_r32(ltq_pci_mapped_cfg + (x))
65 
66 __iomem void *ltq_pci_mapped_cfg;
67 static __iomem void *ltq_pci_membase;
68 
69 static int reset_gpio;
70 static struct clk *clk_pci, *clk_external;
71 static struct resource pci_io_resource;
72 static struct resource pci_mem_resource;
73 static struct pci_ops pci_ops = {
74 	.read	= ltq_pci_read_config_dword,
75 	.write	= ltq_pci_write_config_dword
76 };
77 
78 static struct pci_controller pci_controller = {
79 	.pci_ops	= &pci_ops,
80 	.mem_resource	= &pci_mem_resource,
81 	.mem_offset	= 0x00000000UL,
82 	.io_resource	= &pci_io_resource,
83 	.io_offset	= 0x00000000UL,
84 };
85 
86 static inline u32 ltq_calc_bar11mask(void)
87 {
88 	u32 mem, bar11mask;
89 
90 	/* BAR11MASK value depends on available memory on system. */
91 	mem = get_num_physpages() * PAGE_SIZE;
92 	bar11mask = (0x0ffffff0 & ~((1 << (fls(mem) - 1)) - 1)) | 8;
93 
94 	return bar11mask;
95 }
96 
97 static int ltq_pci_startup(struct platform_device *pdev)
98 {
99 	struct device_node *node = pdev->dev.of_node;
100 	const __be32 *req_mask, *bus_clk;
101 	u32 temp_buffer;
102 
103 	/* get our clocks */
104 	clk_pci = clk_get(&pdev->dev, NULL);
105 	if (IS_ERR(clk_pci)) {
106 		dev_err(&pdev->dev, "failed to get pci clock\n");
107 		return PTR_ERR(clk_pci);
108 	}
109 
110 	clk_external = clk_get(&pdev->dev, "external");
111 	if (IS_ERR(clk_external)) {
112 		clk_put(clk_pci);
113 		dev_err(&pdev->dev, "failed to get external pci clock\n");
114 		return PTR_ERR(clk_external);
115 	}
116 
117 	/* read the bus speed that we want */
118 	bus_clk = of_get_property(node, "lantiq,bus-clock", NULL);
119 	if (bus_clk)
120 		clk_set_rate(clk_pci, *bus_clk);
121 
122 	/* and enable the clocks */
123 	clk_enable(clk_pci);
124 	if (of_find_property(node, "lantiq,external-clock", NULL))
125 		clk_enable(clk_external);
126 	else
127 		clk_disable(clk_external);
128 
129 	/* setup reset gpio used by pci */
130 	reset_gpio = of_get_named_gpio(node, "gpio-reset", 0);
131 	if (gpio_is_valid(reset_gpio)) {
132 		int ret = devm_gpio_request(&pdev->dev,
133 						reset_gpio, "pci-reset");
134 		if (ret) {
135 			dev_err(&pdev->dev,
136 				"failed to request gpio %d\n", reset_gpio);
137 			return ret;
138 		}
139 		gpio_direction_output(reset_gpio, 1);
140 	}
141 
142 	/* enable auto-switching between PCI and EBU */
143 	ltq_pci_w32(0xa, PCI_CR_CLK_CTRL);
144 
145 	/* busy, i.e. configuration is not done, PCI access has to be retried */
146 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_MOD) & ~(1 << 24), PCI_CR_PCI_MOD);
147 	wmb();
148 	/* BUS Master/IO/MEM access */
149 	ltq_pci_cfg_w32(ltq_pci_cfg_r32(PCI_CS_STS_CMD) | 7, PCI_CS_STS_CMD);
150 
151 	/* enable external 2 PCI masters */
152 	temp_buffer = ltq_pci_r32(PCI_CR_PC_ARB);
153 	/* setup the request mask */
154 	req_mask = of_get_property(node, "req-mask", NULL);
155 	if (req_mask)
156 		temp_buffer &= ~((*req_mask & 0xf) << 16);
157 	else
158 		temp_buffer &= ~0xf0000;
159 	/* enable internal arbiter */
160 	temp_buffer |= (1 << INTERNAL_ARB_ENABLE_BIT);
161 	/* enable internal PCI master reqest */
162 	temp_buffer &= (~(3 << PCI_MASTER0_REQ_MASK_2BITS));
163 
164 	/* enable EBU request */
165 	temp_buffer &= (~(3 << PCI_MASTER1_REQ_MASK_2BITS));
166 
167 	/* enable all external masters request */
168 	temp_buffer &= (~(3 << PCI_MASTER2_REQ_MASK_2BITS));
169 	ltq_pci_w32(temp_buffer, PCI_CR_PC_ARB);
170 	wmb();
171 
172 	/* setup BAR memory regions */
173 	ltq_pci_w32(0x18000000, PCI_CR_FCI_ADDR_MAP0);
174 	ltq_pci_w32(0x18400000, PCI_CR_FCI_ADDR_MAP1);
175 	ltq_pci_w32(0x18800000, PCI_CR_FCI_ADDR_MAP2);
176 	ltq_pci_w32(0x18c00000, PCI_CR_FCI_ADDR_MAP3);
177 	ltq_pci_w32(0x19000000, PCI_CR_FCI_ADDR_MAP4);
178 	ltq_pci_w32(0x19400000, PCI_CR_FCI_ADDR_MAP5);
179 	ltq_pci_w32(0x19800000, PCI_CR_FCI_ADDR_MAP6);
180 	ltq_pci_w32(0x19c00000, PCI_CR_FCI_ADDR_MAP7);
181 	ltq_pci_w32(0x1ae00000, PCI_CR_FCI_ADDR_MAP11hg);
182 	ltq_pci_w32(ltq_calc_bar11mask(), PCI_CR_BAR11MASK);
183 	ltq_pci_w32(0, PCI_CR_PCI_ADDR_MAP11);
184 	ltq_pci_w32(0, PCI_CS_BASE_ADDR1);
185 	/* both TX and RX endian swap are enabled */
186 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_EOI) | 3, PCI_CR_PCI_EOI);
187 	wmb();
188 	ltq_pci_w32(ltq_pci_r32(PCI_CR_BAR12MASK) | 0x80000000,
189 		PCI_CR_BAR12MASK);
190 	ltq_pci_w32(ltq_pci_r32(PCI_CR_BAR13MASK) | 0x80000000,
191 		PCI_CR_BAR13MASK);
192 	/*use 8 dw burst length */
193 	ltq_pci_w32(0x303, PCI_CR_FCI_BURST_LENGTH);
194 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_MOD) | (1 << 24), PCI_CR_PCI_MOD);
195 	wmb();
196 
197 	/* setup irq line */
198 	ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_CON) | 0xc, LTQ_EBU_PCC_CON);
199 	ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_IEN) | 0x10, LTQ_EBU_PCC_IEN);
200 
201 	/* toggle reset pin */
202 	if (gpio_is_valid(reset_gpio)) {
203 		__gpio_set_value(reset_gpio, 0);
204 		wmb();
205 		mdelay(1);
206 		__gpio_set_value(reset_gpio, 1);
207 	}
208 	return 0;
209 }
210 
211 static int ltq_pci_probe(struct platform_device *pdev)
212 {
213 	struct resource *res_cfg, *res_bridge;
214 
215 	pci_clear_flags(PCI_PROBE_ONLY);
216 
217 	res_bridge = platform_get_resource(pdev, IORESOURCE_MEM, 1);
218 	ltq_pci_membase = devm_ioremap_resource(&pdev->dev, res_bridge);
219 	if (IS_ERR(ltq_pci_membase))
220 		return PTR_ERR(ltq_pci_membase);
221 
222 	res_cfg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
223 	ltq_pci_mapped_cfg = devm_ioremap_resource(&pdev->dev, res_cfg);
224 	if (IS_ERR(ltq_pci_mapped_cfg))
225 		return PTR_ERR(ltq_pci_mapped_cfg);
226 
227 	ltq_pci_startup(pdev);
228 
229 	pci_load_of_ranges(&pci_controller, pdev->dev.of_node);
230 	register_pci_controller(&pci_controller);
231 	return 0;
232 }
233 
234 static const struct of_device_id ltq_pci_match[] = {
235 	{ .compatible = "lantiq,pci-xway" },
236 	{},
237 };
238 MODULE_DEVICE_TABLE(of, ltq_pci_match);
239 
240 static struct platform_driver ltq_pci_driver = {
241 	.probe = ltq_pci_probe,
242 	.driver = {
243 		.name = "pci-xway",
244 		.of_match_table = ltq_pci_match,
245 	},
246 };
247 
248 int __init pcibios_init(void)
249 {
250 	int ret = platform_driver_register(&ltq_pci_driver);
251 	if (ret)
252 		pr_info("pci-xway: Error registering platform driver!");
253 	return ret;
254 }
255 
256 arch_initcall(pcibios_init);
257