xref: /openbmc/linux/drivers/mfd/lpc_sch.c (revision 04dc82e1)
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 GPIOBASE	0x44
26 #define GPIO_IO_SIZE	64
27 #define GPIO_IO_SIZE_CENTERTON	128
28 
29 /* Intel Quark X1000 GPIO IRQ Number */
30 #define GPIO_IRQ_QUARK_X1000	9
31 
32 #define WDTBASE		0x84
33 #define WDT_IO_SIZE	64
34 
35 enum sch_chipsets {
36 	LPC_SCH = 0,		/* Intel Poulsbo SCH */
37 	LPC_ITC,		/* Intel Tunnel Creek */
38 	LPC_CENTERTON,		/* Intel Centerton */
39 	LPC_QUARK_X1000,	/* Intel Quark X1000 */
40 };
41 
42 struct lpc_sch_info {
43 	unsigned int io_size_smbus;
44 	unsigned int io_size_gpio;
45 	unsigned int io_size_wdt;
46 	int irq_gpio;
47 };
48 
49 static struct lpc_sch_info sch_chipset_info[] = {
50 	[LPC_SCH] = {
51 		.io_size_smbus = SMBUS_IO_SIZE,
52 		.io_size_gpio = GPIO_IO_SIZE,
53 		.irq_gpio = -1,
54 	},
55 	[LPC_ITC] = {
56 		.io_size_smbus = SMBUS_IO_SIZE,
57 		.io_size_gpio = GPIO_IO_SIZE,
58 		.io_size_wdt = WDT_IO_SIZE,
59 		.irq_gpio = -1,
60 	},
61 	[LPC_CENTERTON] = {
62 		.io_size_smbus = SMBUS_IO_SIZE,
63 		.io_size_gpio = GPIO_IO_SIZE_CENTERTON,
64 		.io_size_wdt = WDT_IO_SIZE,
65 		.irq_gpio = -1,
66 	},
67 	[LPC_QUARK_X1000] = {
68 		.io_size_gpio = GPIO_IO_SIZE,
69 		.irq_gpio = GPIO_IRQ_QUARK_X1000,
70 		.io_size_wdt = WDT_IO_SIZE,
71 	},
72 };
73 
74 static const struct pci_device_id lpc_sch_ids[] = {
75 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_SCH_LPC), LPC_SCH },
76 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_ITC_LPC), LPC_ITC },
77 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_CENTERTON_ILB), LPC_CENTERTON },
78 	{ PCI_VDEVICE(INTEL, PCI_DEVICE_ID_INTEL_QUARK_X1000_ILB), LPC_QUARK_X1000 },
79 	{ 0, }
80 };
81 MODULE_DEVICE_TABLE(pci, lpc_sch_ids);
82 
83 #define LPC_NO_RESOURCE		1
84 #define LPC_SKIP_RESOURCE	2
85 
86 static int lpc_sch_get_io(struct pci_dev *pdev, int where, const char *name,
87 			  struct resource *res, int size)
88 {
89 	unsigned int base_addr_cfg;
90 	unsigned short base_addr;
91 
92 	if (size == 0)
93 		return LPC_NO_RESOURCE;
94 
95 	pci_read_config_dword(pdev, where, &base_addr_cfg);
96 	base_addr = 0;
97 	if (!(base_addr_cfg & (1 << 31)))
98 		dev_warn(&pdev->dev, "Decode of the %s I/O range disabled\n",
99 			 name);
100 	else
101 		base_addr = (unsigned short)base_addr_cfg;
102 
103 	if (base_addr == 0) {
104 		dev_warn(&pdev->dev, "I/O space for %s uninitialized\n", name);
105 		return LPC_SKIP_RESOURCE;
106 	}
107 
108 	res->start = base_addr;
109 	res->end = base_addr + size - 1;
110 	res->flags = IORESOURCE_IO;
111 
112 	return 0;
113 }
114 
115 static int lpc_sch_populate_cell(struct pci_dev *pdev, int where,
116 				 const char *name, int size, int irq,
117 				 int id, struct mfd_cell *cell)
118 {
119 	struct resource *res;
120 	int ret;
121 
122 	res = devm_kcalloc(&pdev->dev, 2, sizeof(*res), GFP_KERNEL);
123 	if (!res)
124 		return -ENOMEM;
125 
126 	ret = lpc_sch_get_io(pdev, where, name, res, size);
127 	if (ret)
128 		return ret;
129 
130 	memset(cell, 0, sizeof(*cell));
131 
132 	cell->name = name;
133 	cell->resources = res;
134 	cell->num_resources = 1;
135 	cell->ignore_resource_conflicts = true;
136 	cell->id = id;
137 
138 	/* Check if we need to add an IRQ resource */
139 	if (irq < 0)
140 		return 0;
141 
142 	res++;
143 
144 	res->start = irq;
145 	res->end = irq;
146 	res->flags = IORESOURCE_IRQ;
147 
148 	cell->num_resources++;
149 
150 	return 0;
151 }
152 
153 static int lpc_sch_probe(struct pci_dev *dev, const struct pci_device_id *id)
154 {
155 	struct mfd_cell lpc_sch_cells[3];
156 	struct lpc_sch_info *info = &sch_chipset_info[id->driver_data];
157 	unsigned int cells = 0;
158 	int ret;
159 
160 	ret = lpc_sch_populate_cell(dev, SMBASE, "isch_smbus",
161 				    info->io_size_smbus, -1,
162 				    id->device, &lpc_sch_cells[cells]);
163 	if (ret < 0)
164 		return ret;
165 	if (ret == 0)
166 		cells++;
167 
168 	ret = lpc_sch_populate_cell(dev, GPIOBASE, "sch_gpio",
169 				    info->io_size_gpio, info->irq_gpio,
170 				    id->device, &lpc_sch_cells[cells]);
171 	if (ret < 0)
172 		return ret;
173 	if (ret == 0)
174 		cells++;
175 
176 	ret = lpc_sch_populate_cell(dev, WDTBASE, "ie6xx_wdt",
177 				    info->io_size_wdt, -1,
178 				    id->device, &lpc_sch_cells[cells]);
179 	if (ret < 0)
180 		return ret;
181 	if (ret == 0)
182 		cells++;
183 
184 	if (cells == 0) {
185 		dev_err(&dev->dev, "All decode registers disabled.\n");
186 		return -ENODEV;
187 	}
188 
189 	return mfd_add_devices(&dev->dev, 0, lpc_sch_cells, cells, NULL, 0, NULL);
190 }
191 
192 static void lpc_sch_remove(struct pci_dev *dev)
193 {
194 	mfd_remove_devices(&dev->dev);
195 }
196 
197 static struct pci_driver lpc_sch_driver = {
198 	.name		= "lpc_sch",
199 	.id_table	= lpc_sch_ids,
200 	.probe		= lpc_sch_probe,
201 	.remove		= lpc_sch_remove,
202 };
203 
204 module_pci_driver(lpc_sch_driver);
205 
206 MODULE_AUTHOR("Denis Turischev <denis@compulab.co.il>");
207 MODULE_DESCRIPTION("LPC interface for Intel Poulsbo SCH");
208 MODULE_LICENSE("GPL");
209