summaryrefslogtreecommitdiffstats
path: root/drivers/pci/host/pcie-iproc.c
blob: d77481ea553e08de04527f885df842e3dc2f8d84 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
/*
 * Copyright (C) 2014 Hauke Mehrtens <hauke@hauke-m.de>
 * Copyright (C) 2015 Broadcom Corporatcommon ion
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation version 2.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/pci.h>
#include <linux/msi.h>
#include <linux/clk.h>
#include <linux/module.h>
#include <linux/mbus.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/platform_device.h>
#include <linux/of_address.h>
#include <linux/of_pci.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>
#include <linux/phy/phy.h>

#include "pcie-iproc.h"

#define CLK_CONTROL_OFFSET           0x000
#define EP_MODE_SURVIVE_PERST_SHIFT  1
#define EP_MODE_SURVIVE_PERST        BIT(EP_MODE_SURVIVE_PERST_SHIFT)
#define RC_PCIE_RST_OUTPUT_SHIFT     0
#define RC_PCIE_RST_OUTPUT           BIT(RC_PCIE_RST_OUTPUT_SHIFT)

#define CFG_IND_ADDR_OFFSET          0x120
#define CFG_IND_ADDR_MASK            0x00001ffc

#define CFG_IND_DATA_OFFSET          0x124

#define CFG_ADDR_OFFSET              0x1f8
#define CFG_ADDR_BUS_NUM_SHIFT       20
#define CFG_ADDR_BUS_NUM_MASK        0x0ff00000
#define CFG_ADDR_DEV_NUM_SHIFT       15
#define CFG_ADDR_DEV_NUM_MASK        0x000f8000
#define CFG_ADDR_FUNC_NUM_SHIFT      12
#define CFG_ADDR_FUNC_NUM_MASK       0x00007000
#define CFG_ADDR_REG_NUM_SHIFT       2
#define CFG_ADDR_REG_NUM_MASK        0x00000ffc
#define CFG_ADDR_CFG_TYPE_SHIFT      0
#define CFG_ADDR_CFG_TYPE_MASK       0x00000003

#define CFG_DATA_OFFSET              0x1fc

#define SYS_RC_INTX_EN               0x330
#define SYS_RC_INTX_MASK             0xf

static inline struct iproc_pcie *sys_to_pcie(struct pci_sys_data *sys)
{
	return sys->private_data;
}

/**
 * Note access to the configuration registers are protected at the higher layer
 * by 'pci_lock' in drivers/pci/access.c
 */
static void __iomem *iproc_pcie_map_cfg_bus(struct pci_bus *bus,
					    unsigned int devfn,
					    int where)
{
	struct pci_sys_data *sys = bus->sysdata;
	struct iproc_pcie *pcie = sys_to_pcie(sys);
	unsigned slot = PCI_SLOT(devfn);
	unsigned fn = PCI_FUNC(devfn);
	unsigned busno = bus->number;
	u32 val;

	/* root complex access */
	if (busno == 0) {
		if (slot >= 1)
			return NULL;
		writel(where & CFG_IND_ADDR_MASK,
		       pcie->base + CFG_IND_ADDR_OFFSET);
		return (pcie->base + CFG_IND_DATA_OFFSET);
	}

	if (fn > 1)
		return NULL;

	/* EP device access */
	val = (busno << CFG_ADDR_BUS_NUM_SHIFT) |
		(slot << CFG_ADDR_DEV_NUM_SHIFT) |
		(fn << CFG_ADDR_FUNC_NUM_SHIFT) |
		(where & CFG_ADDR_REG_NUM_MASK) |
		(1 & CFG_ADDR_CFG_TYPE_MASK);
	writel(val, pcie->base + CFG_ADDR_OFFSET);

	return (pcie->base + CFG_DATA_OFFSET);
}

static struct pci_ops iproc_pcie_ops = {
	.map_bus = iproc_pcie_map_cfg_bus,
	.read = pci_generic_config_read32,
	.write = pci_generic_config_write32,
};

static void iproc_pcie_reset(struct iproc_pcie *pcie)
{
	u32 val;

	/*
	 * Configure the PCIe controller as root complex and send a downstream
	 * reset
	 */
	val = EP_MODE_SURVIVE_PERST | RC_PCIE_RST_OUTPUT;
	writel(val, pcie->base + CLK_CONTROL_OFFSET);
	udelay(250);
	val &= ~EP_MODE_SURVIVE_PERST;
	writel(val, pcie->base + CLK_CONTROL_OFFSET);
	msleep(250);
}

static int iproc_pcie_check_link(struct iproc_pcie *pcie, struct pci_bus *bus)
{
	u8 hdr_type;
	u32 link_ctrl;
	u16 pos, link_status;
	int link_is_active = 0;

	/* make sure we are not in EP mode */
	pci_bus_read_config_byte(bus, 0, PCI_HEADER_TYPE, &hdr_type);
	if ((hdr_type & 0x7f) != PCI_HEADER_TYPE_BRIDGE) {
		dev_err(pcie->dev, "in EP mode, hdr=%#02x\n", hdr_type);
		return -EFAULT;
	}

	/* force class to PCI_CLASS_BRIDGE_PCI (0x0604) */
	pci_bus_write_config_word(bus, 0, PCI_CLASS_DEVICE,
				  PCI_CLASS_BRIDGE_PCI);

	/* check link status to see if link is active */
	pos = pci_bus_find_capability(bus, 0, PCI_CAP_ID_EXP);
	pci_bus_read_config_word(bus, 0, pos + PCI_EXP_LNKSTA, &link_status);
	if (link_status & PCI_EXP_LNKSTA_NLW)
		link_is_active = 1;

	if (!link_is_active) {
		/* try GEN 1 link speed */
#define PCI_LINK_STATUS_CTRL_2_OFFSET 0x0dc
#define PCI_TARGET_LINK_SPEED_MASK    0xf
#define PCI_TARGET_LINK_SPEED_GEN2    0x2
#define PCI_TARGET_LINK_SPEED_GEN1    0x1
		pci_bus_read_config_dword(bus, 0,
					  PCI_LINK_STATUS_CTRL_2_OFFSET,
					  &link_ctrl);
		if ((link_ctrl & PCI_TARGET_LINK_SPEED_MASK) ==
		    PCI_TARGET_LINK_SPEED_GEN2) {
			link_ctrl &= ~PCI_TARGET_LINK_SPEED_MASK;
			link_ctrl |= PCI_TARGET_LINK_SPEED_GEN1;
			pci_bus_write_config_dword(bus, 0,
					   PCI_LINK_STATUS_CTRL_2_OFFSET,
					   link_ctrl);
			msleep(100);

			pos = pci_bus_find_capability(bus, 0, PCI_CAP_ID_EXP);
			pci_bus_read_config_word(bus, 0, pos + PCI_EXP_LNKSTA,
						 &link_status);
			if (link_status & PCI_EXP_LNKSTA_NLW)
				link_is_active = 1;
		}
	}

	dev_info(pcie->dev, "link: %s\n", link_is_active ? "UP" : "DOWN");

	return link_is_active ? 0 : -ENODEV;
}

static void iproc_pcie_enable(struct iproc_pcie *pcie)
{
	writel(SYS_RC_INTX_MASK, pcie->base + SYS_RC_INTX_EN);
}

int iproc_pcie_setup(struct iproc_pcie *pcie, struct list_head *res)
{
	int ret;
	struct pci_bus *bus;

	if (!pcie || !pcie->dev || !pcie->base)
		return -EINVAL;

	if (pcie->phy) {
		ret = phy_init(pcie->phy);
		if (ret) {
			dev_err(pcie->dev, "unable to initialize PCIe PHY\n");
			return ret;
		}

		ret = phy_power_on(pcie->phy);
		if (ret) {
			dev_err(pcie->dev, "unable to power on PCIe PHY\n");
			goto err_exit_phy;
		}

	}

	iproc_pcie_reset(pcie);

	pcie->sysdata.private_data = pcie;

	bus = pci_create_root_bus(pcie->dev, 0, &iproc_pcie_ops,
				  &pcie->sysdata, res);
	if (!bus) {
		dev_err(pcie->dev, "unable to create PCI root bus\n");
		ret = -ENOMEM;
		goto err_power_off_phy;
	}
	pcie->root_bus = bus;

	ret = iproc_pcie_check_link(pcie, bus);
	if (ret) {
		dev_err(pcie->dev, "no PCIe EP device detected\n");
		goto err_rm_root_bus;
	}

	iproc_pcie_enable(pcie);

	pci_scan_child_bus(bus);
	pci_assign_unassigned_bus_resources(bus);
	pci_fixup_irqs(pci_common_swizzle, pcie->map_irq);
	pci_bus_add_devices(bus);

	return 0;

err_rm_root_bus:
	pci_stop_root_bus(bus);
	pci_remove_root_bus(bus);

err_power_off_phy:
	if (pcie->phy)
		phy_power_off(pcie->phy);
err_exit_phy:
	if (pcie->phy)
		phy_exit(pcie->phy);

	return ret;
}
EXPORT_SYMBOL(iproc_pcie_setup);

int iproc_pcie_remove(struct iproc_pcie *pcie)
{
	pci_stop_root_bus(pcie->root_bus);
	pci_remove_root_bus(pcie->root_bus);

	if (pcie->phy) {
		phy_power_off(pcie->phy);
		phy_exit(pcie->phy);
	}

	return 0;
}
EXPORT_SYMBOL(iproc_pcie_remove);

MODULE_AUTHOR("Ray Jui <rjui@broadcom.com>");
MODULE_DESCRIPTION("Broadcom iPROC PCIe common driver");
MODULE_LICENSE("GPL v2");