xref: /openbmc/linux/drivers/mfd/lpc_sch.c (revision 0545810f)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  lpc_sch.c - LPC interface for Intel Poulsbo SCH
4  *
5  *  LPC bridge function of the Intel SCH contains many other
6  *  functional units, such as Interrupt controllers, Timers,
7  *  Power Management, System Management, GPIO, RTC, and LPC
8  *  Configuration Registers.
9  *
10  *  Copyright (c) 2010 CompuLab Ltd
11  *  Copyright (c) 2014 Intel Corp.
12  *  Author: Denis Turischev <denis@compulab.co.il>
13  */
14 
15 #include <linux/kernel.h>
16 #include <linux/module.h>
17 #include <linux/errno.h>
18 #include <linux/acpi.h>
19 #include <linux/pci.h>
20 #include <linux/mfd/core.h>
21 
22 #define SMBASE		0x40
23 #define SMBUS_IO_SIZE	64
24 
25 #define GPIO_BASE	0x44
26 #define GPIO_IO_SIZE	64
27 #define GPIO_IO_SIZE_CENTERTON	128
28 
29 #define WDTBASE		0x84
30 #define WDT_IO_SIZE	64
31 
32 enum sch_chipsets {
33 	LPC_SCH = 0,		/* Intel Poulsbo SCH */
34 	LPC_ITC,		/* Intel Tunnel Creek */
35 	LPC_CENTERTON,		/* Intel Centerton */
36 	LPC_QUARK_X1000,	/* Intel Quark X1000 */
37 };
38 
39 struct lpc_sch_info {
40 	unsigned int io_size_smbus;
41 	unsigned int io_size_gpio;
42 	unsigned int io_size_wdt;
43 };
44 
45 static struct lpc_sch_info sch_chipset_info[] = {
46 	[LPC_SCH] = {
47 		.io_size_smbus = SMBUS_IO_SIZE,
48 		.io_size_gpio = GPIO_IO_SIZE,
49 	},
50 	[LPC_ITC] = {
51 		.io_size_smbus = SMBUS_IO_SIZE,
52 		.io_size_gpio = GPIO_IO_SIZE,
53 		.io_size_wdt = WDT_IO_SIZE,
54 	},
55 	[LPC_CENTERTON] = {
56 		.io_size_smbus = SMBUS_IO_SIZE,
57 		.io_size_gpio = GPIO_IO_SIZE_CENTERTON,
58 		.io_size_wdt = WDT_IO_SIZE,
59 	},
60 	[LPC_QUARK_X1000] = {
61 		.io_size_gpio = GPIO_IO_SIZE,
62 		.io_size_wdt = WDT_IO_SIZE,
63 	},
64 };
65 
66 static const struct pci_device_id lpc_sch_ids[] = {
67 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_SCH_LPC), LPC_SCH },
68 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ITC_LPC), LPC_ITC },
69 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_CENTERTON_ILB), LPC_CENTERTON },
70 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_QUARK_X1000_ILB), LPC_QUARK_X1000 },
71 	{ 0, }
72 };
73 MODULE_DEVICE_TABLE(pci, lpc_sch_ids);
74 
75 #define LPC_NO_RESOURCE		1
76 #define LPC_SKIP_RESOURCE	2
77 
78 static int lpc_sch_get_io(struct pci_dev *pdev, int where, const char *name,
79 			  struct resource *res, int size)
80 {
81 	unsigned int base_addr_cfg;
82 	unsigned short base_addr;
83 
84 	if (size == 0)
85 		return LPC_NO_RESOURCE;
86 
87 	pci_read_config_dword(pdev, where, &base_addr_cfg);
88 	base_addr = 0;
89 	if (!(base_addr_cfg & (1 << 31)))
90 		dev_warn(&pdev->dev, "Decode of the %s I/O range disabled\n",
91 			 name);
92 	else
93 		base_addr = (unsigned short)base_addr_cfg;
94 
95 	if (base_addr == 0) {
96 		dev_warn(&pdev->dev, "I/O space for %s uninitialized\n", name);
97 		return LPC_SKIP_RESOURCE;
98 	}
99 
100 	res->start = base_addr;
101 	res->end = base_addr + size - 1;
102 	res->flags = IORESOURCE_IO;
103 
104 	return 0;
105 }
106 
107 static int lpc_sch_populate_cell(struct pci_dev *pdev, int where,
108 				 const char *name, int size, int id,
109 				 struct mfd_cell *cell)
110 {
111 	struct resource *res;
112 	int ret;
113 
114 	res = devm_kzalloc(&pdev->dev, sizeof(*res), GFP_KERNEL);
115 	if (!res)
116 		return -ENOMEM;
117 
118 	ret = lpc_sch_get_io(pdev, where, name, res, size);
119 	if (ret)
120 		return ret;
121 
122 	memset(cell, 0, sizeof(*cell));
123 
124 	cell->name = name;
125 	cell->resources = res;
126 	cell->num_resources = 1;
127 	cell->ignore_resource_conflicts = true;
128 	cell->id = id;
129 
130 	return 0;
131 }
132 
133 static int lpc_sch_probe(struct pci_dev *dev, const struct pci_device_id *id)
134 {
135 	struct mfd_cell lpc_sch_cells[3];
136 	struct lpc_sch_info *info = &sch_chipset_info[id->driver_data];
137 	unsigned int cells = 0;
138 	int ret;
139 
140 	ret = lpc_sch_populate_cell(dev, SMBASE, "isch_smbus",
141 				    info->io_size_smbus,
142 				    id->device, &lpc_sch_cells[cells]);
143 	if (ret < 0)
144 		return ret;
145 	if (ret == 0)
146 		cells++;
147 
148 	ret = lpc_sch_populate_cell(dev, GPIO_BASE, "sch_gpio",
149 				    info->io_size_gpio,
150 				    id->device, &lpc_sch_cells[cells]);
151 	if (ret < 0)
152 		return ret;
153 	if (ret == 0)
154 		cells++;
155 
156 	ret = lpc_sch_populate_cell(dev, WDTBASE, "ie6xx_wdt",
157 				    info->io_size_wdt,
158 				    id->device, &lpc_sch_cells[cells]);
159 	if (ret < 0)
160 		return ret;
161 	if (ret == 0)
162 		cells++;
163 
164 	if (cells == 0) {
165 		dev_err(&dev->dev, "All decode registers disabled.\n");
166 		return -ENODEV;
167 	}
168 
169 	return mfd_add_devices(&dev->dev, 0, lpc_sch_cells, cells, NULL, 0, NULL);
170 }
171 
172 static void lpc_sch_remove(struct pci_dev *dev)
173 {
174 	mfd_remove_devices(&dev->dev);
175 }
176 
177 static struct pci_driver lpc_sch_driver = {
178 	.name		= "lpc_sch",
179 	.id_table	= lpc_sch_ids,
180 	.probe		= lpc_sch_probe,
181 	.remove		= lpc_sch_remove,
182 };
183 
184 module_pci_driver(lpc_sch_driver);
185 
186 MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>");
187 MODULE_DESCRIPTION("LPC interface for Intel Poulsbo SCH");
188 MODULE_LICENSE("GPL");
189