xref: /openbmc/linux/arch/mips/pci/pci-lantiq.c (revision d9fd5a71)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *
4  *  Copyright (C) 2010 John Crispin <john@phrozen.org>
5  */
6 
7 #include <linux/types.h>
8 #include <linux/pci.h>
9 #include <linux/kernel.h>
10 #include <linux/init.h>
11 #include <linux/delay.h>
12 #include <linux/mm.h>
13 #include <linux/vmalloc.h>
14 #include <linux/clk.h>
15 #include <linux/of_platform.h>
16 #include <linux/of_gpio.h>
17 #include <linux/of_irq.h>
18 #include <linux/of_pci.h>
19 
20 #include <asm/addrspace.h>
21 
22 #include <lantiq_soc.h>
23 #include <lantiq_irq.h>
24 
25 #include "pci-lantiq.h"
26 
27 #define PCI_CR_FCI_ADDR_MAP0		0x00C0
28 #define PCI_CR_FCI_ADDR_MAP1		0x00C4
29 #define PCI_CR_FCI_ADDR_MAP2		0x00C8
30 #define PCI_CR_FCI_ADDR_MAP3		0x00CC
31 #define PCI_CR_FCI_ADDR_MAP4		0x00D0
32 #define PCI_CR_FCI_ADDR_MAP5		0x00D4
33 #define PCI_CR_FCI_ADDR_MAP6		0x00D8
34 #define PCI_CR_FCI_ADDR_MAP7		0x00DC
35 #define PCI_CR_CLK_CTRL			0x0000
36 #define PCI_CR_PCI_MOD			0x0030
37 #define PCI_CR_PC_ARB			0x0080
38 #define PCI_CR_FCI_ADDR_MAP11hg		0x00E4
39 #define PCI_CR_BAR11MASK		0x0044
40 #define PCI_CR_BAR12MASK		0x0048
41 #define PCI_CR_BAR13MASK		0x004C
42 #define PCI_CS_BASE_ADDR1		0x0010
43 #define PCI_CR_PCI_ADDR_MAP11		0x0064
44 #define PCI_CR_FCI_BURST_LENGTH		0x00E8
45 #define PCI_CR_PCI_EOI			0x002C
46 #define PCI_CS_STS_CMD			0x0004
47 
48 #define PCI_MASTER0_REQ_MASK_2BITS	8
49 #define PCI_MASTER1_REQ_MASK_2BITS	10
50 #define PCI_MASTER2_REQ_MASK_2BITS	12
51 #define INTERNAL_ARB_ENABLE_BIT		0
52 
53 #define LTQ_CGU_IFCCR		0x0018
54 #define LTQ_CGU_PCICR		0x0034
55 
56 #define ltq_pci_w32(x, y)	ltq_w32((x), ltq_pci_membase + (y))
57 #define ltq_pci_r32(x)		ltq_r32(ltq_pci_membase + (x))
58 
59 #define ltq_pci_cfg_w32(x, y)	ltq_w32((x), ltq_pci_mapped_cfg + (y))
60 #define ltq_pci_cfg_r32(x)	ltq_r32(ltq_pci_mapped_cfg + (x))
61 
62 __iomem void *ltq_pci_mapped_cfg;
63 static __iomem void *ltq_pci_membase;
64 
65 static int reset_gpio;
66 static struct clk *clk_pci, *clk_external;
67 static struct resource pci_io_resource;
68 static struct resource pci_mem_resource;
69 static struct pci_ops pci_ops = {
70 	.read	= ltq_pci_read_config_dword,
71 	.write	= ltq_pci_write_config_dword
72 };
73 
74 static struct pci_controller pci_controller = {
75 	.pci_ops	= &pci_ops,
76 	.mem_resource	= &pci_mem_resource,
77 	.mem_offset	= 0x00000000UL,
78 	.io_resource	= &pci_io_resource,
79 	.io_offset	= 0x00000000UL,
80 };
81 
82 static inline u32 ltq_calc_bar11mask(void)
83 {
84 	u32 mem, bar11mask;
85 
86 	/* BAR11MASK value depends on available memory on system. */
87 	mem = get_num_physpages() * PAGE_SIZE;
88 	bar11mask = (0x0ffffff0 & ~((1 << (fls(mem) - 1)) - 1)) | 8;
89 
90 	return bar11mask;
91 }
92 
93 static int ltq_pci_startup(struct platform_device *pdev)
94 {
95 	struct device_node *node = pdev->dev.of_node;
96 	const __be32 *req_mask, *bus_clk;
97 	u32 temp_buffer;
98 
99 	/* get our clocks */
100 	clk_pci = clk_get(&pdev->dev, NULL);
101 	if (IS_ERR(clk_pci)) {
102 		dev_err(&pdev->dev, "failed to get pci clock\n");
103 		return PTR_ERR(clk_pci);
104 	}
105 
106 	clk_external = clk_get(&pdev->dev, "external");
107 	if (IS_ERR(clk_external)) {
108 		clk_put(clk_pci);
109 		dev_err(&pdev->dev, "failed to get external pci clock\n");
110 		return PTR_ERR(clk_external);
111 	}
112 
113 	/* read the bus speed that we want */
114 	bus_clk = of_get_property(node, "lantiq,bus-clock", NULL);
115 	if (bus_clk)
116 		clk_set_rate(clk_pci, *bus_clk);
117 
118 	/* and enable the clocks */
119 	clk_enable(clk_pci);
120 	if (of_find_property(node, "lantiq,external-clock", NULL))
121 		clk_enable(clk_external);
122 	else
123 		clk_disable(clk_external);
124 
125 	/* setup reset gpio used by pci */
126 	reset_gpio = of_get_named_gpio(node, "gpio-reset", 0);
127 	if (gpio_is_valid(reset_gpio)) {
128 		int ret = devm_gpio_request(&pdev->dev,
129 						reset_gpio, "pci-reset");
130 		if (ret) {
131 			dev_err(&pdev->dev,
132 				"failed to request gpio %d\n", reset_gpio);
133 			return ret;
134 		}
135 		gpio_direction_output(reset_gpio, 1);
136 	}
137 
138 	/* enable auto-switching between PCI and EBU */
139 	ltq_pci_w32(0xa, PCI_CR_CLK_CTRL);
140 
141 	/* busy, i.e. configuration is not done, PCI access has to be retried */
142 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_MOD) & ~(1 << 24), PCI_CR_PCI_MOD);
143 	wmb();
144 	/* BUS Master/IO/MEM access */
145 	ltq_pci_cfg_w32(ltq_pci_cfg_r32(PCI_CS_STS_CMD) | 7, PCI_CS_STS_CMD);
146 
147 	/* enable external 2 PCI masters */
148 	temp_buffer = ltq_pci_r32(PCI_CR_PC_ARB);
149 	/* setup the request mask */
150 	req_mask = of_get_property(node, "req-mask", NULL);
151 	if (req_mask)
152 		temp_buffer &= ~((*req_mask & 0xf) << 16);
153 	else
154 		temp_buffer &= ~0xf0000;
155 	/* enable internal arbiter */
156 	temp_buffer |= (1 << INTERNAL_ARB_ENABLE_BIT);
157 	/* enable internal PCI master reqest */
158 	temp_buffer &= (~(3 << PCI_MASTER0_REQ_MASK_2BITS));
159 
160 	/* enable EBU request */
161 	temp_buffer &= (~(3 << PCI_MASTER1_REQ_MASK_2BITS));
162 
163 	/* enable all external masters request */
164 	temp_buffer &= (~(3 << PCI_MASTER2_REQ_MASK_2BITS));
165 	ltq_pci_w32(temp_buffer, PCI_CR_PC_ARB);
166 	wmb();
167 
168 	/* setup BAR memory regions */
169 	ltq_pci_w32(0x18000000, PCI_CR_FCI_ADDR_MAP0);
170 	ltq_pci_w32(0x18400000, PCI_CR_FCI_ADDR_MAP1);
171 	ltq_pci_w32(0x18800000, PCI_CR_FCI_ADDR_MAP2);
172 	ltq_pci_w32(0x18c00000, PCI_CR_FCI_ADDR_MAP3);
173 	ltq_pci_w32(0x19000000, PCI_CR_FCI_ADDR_MAP4);
174 	ltq_pci_w32(0x19400000, PCI_CR_FCI_ADDR_MAP5);
175 	ltq_pci_w32(0x19800000, PCI_CR_FCI_ADDR_MAP6);
176 	ltq_pci_w32(0x19c00000, PCI_CR_FCI_ADDR_MAP7);
177 	ltq_pci_w32(0x1ae00000, PCI_CR_FCI_ADDR_MAP11hg);
178 	ltq_pci_w32(ltq_calc_bar11mask(), PCI_CR_BAR11MASK);
179 	ltq_pci_w32(0, PCI_CR_PCI_ADDR_MAP11);
180 	ltq_pci_w32(0, PCI_CS_BASE_ADDR1);
181 	/* both TX and RX endian swap are enabled */
182 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_EOI) | 3, PCI_CR_PCI_EOI);
183 	wmb();
184 	ltq_pci_w32(ltq_pci_r32(PCI_CR_BAR12MASK) | 0x80000000,
185 		PCI_CR_BAR12MASK);
186 	ltq_pci_w32(ltq_pci_r32(PCI_CR_BAR13MASK) | 0x80000000,
187 		PCI_CR_BAR13MASK);
188 	/*use 8 dw burst length */
189 	ltq_pci_w32(0x303, PCI_CR_FCI_BURST_LENGTH);
190 	ltq_pci_w32(ltq_pci_r32(PCI_CR_PCI_MOD) | (1 << 24), PCI_CR_PCI_MOD);
191 	wmb();
192 
193 	/* setup irq line */
194 	ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_CON) | 0xc, LTQ_EBU_PCC_CON);
195 	ltq_ebu_w32(ltq_ebu_r32(LTQ_EBU_PCC_IEN) | 0x10, LTQ_EBU_PCC_IEN);
196 
197 	/* toggle reset pin */
198 	if (gpio_is_valid(reset_gpio)) {
199 		__gpio_set_value(reset_gpio, 0);
200 		wmb();
201 		mdelay(1);
202 		__gpio_set_value(reset_gpio, 1);
203 	}
204 	return 0;
205 }
206 
207 static int ltq_pci_probe(struct platform_device *pdev)
208 {
209 	struct resource *res_cfg, *res_bridge;
210 
211 	pci_clear_flags(PCI_PROBE_ONLY);
212 
213 	res_bridge = platform_get_resource(pdev, IORESOURCE_MEM, 1);
214 	ltq_pci_membase = devm_ioremap_resource(&pdev->dev, res_bridge);
215 	if (IS_ERR(ltq_pci_membase))
216 		return PTR_ERR(ltq_pci_membase);
217 
218 	res_cfg = platform_get_resource(pdev, IORESOURCE_MEM, 0);
219 	ltq_pci_mapped_cfg = devm_ioremap_resource(&pdev->dev, res_cfg);
220 	if (IS_ERR(ltq_pci_mapped_cfg))
221 		return PTR_ERR(ltq_pci_mapped_cfg);
222 
223 	ltq_pci_startup(pdev);
224 
225 	pci_load_of_ranges(&pci_controller, pdev->dev.of_node);
226 	register_pci_controller(&pci_controller);
227 	return 0;
228 }
229 
230 static const struct of_device_id ltq_pci_match[] = {
231 	{ .compatible = "lantiq,pci-xway" },
232 	{},
233 };
234 
235 static struct platform_driver ltq_pci_driver = {
236 	.probe = ltq_pci_probe,
237 	.driver = {
238 		.name = "pci-xway",
239 		.of_match_table = ltq_pci_match,
240 	},
241 };
242 
243 int __init pcibios_init(void)
244 {
245 	int ret = platform_driver_register(&ltq_pci_driver);
246 	if (ret)
247 		pr_info("pci-xway: Error registering platform driver!");
248 	return ret;
249 }
250 
251 arch_initcall(pcibios_init);
252