xref: /openbmc/linux/drivers/mfd/vx855.c (revision e2c75e76)
1 /*
2  * Linux multi-function-device driver (MFD) for the integrated peripherals
3  * of the VIA VX855 chipset
4  *
5  * Copyright (C) 2009 VIA Technologies, Inc.
6  * Copyright (C) 2010 One Laptop per Child
7  * Author: Harald Welte <HaraldWelte@viatech.com>
8  * All rights reserved.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation; either version 2 of
13  * the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23  * MA 02111-1307 USA
24  *
25  */
26 
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/device.h>
30 #include <linux/platform_device.h>
31 #include <linux/pci.h>
32 #include <linux/mfd/core.h>
33 
34 /* offset into pci config space indicating the 16bit register containing
35  * the power management IO space base */
36 #define VX855_CFG_PMIO_OFFSET	0x88
37 
38 /* ACPI I/O Space registers */
39 #define VX855_PMIO_ACPI		0x00
40 #define VX855_PMIO_ACPI_LEN	0x0b
41 
42 /* Processor Power Management */
43 #define VX855_PMIO_PPM		0x10
44 #define VX855_PMIO_PPM_LEN	0x08
45 
46 /* General Purpose Power Management */
47 #define VX855_PMIO_GPPM		0x20
48 #define VX855_PMIO_R_GPI	0x48
49 #define VX855_PMIO_R_GPO	0x4c
50 #define VX855_PMIO_GPPM_LEN	0x33
51 
52 #define VSPIC_MMIO_SIZE	0x1000
53 
54 static struct resource vx855_gpio_resources[] = {
55 	{
56 		.flags = IORESOURCE_IO,
57 	},
58 	{
59 		.flags = IORESOURCE_IO,
60 	},
61 };
62 
63 static const struct mfd_cell vx855_cells[] = {
64 	{
65 		.name = "vx855_gpio",
66 		.num_resources = ARRAY_SIZE(vx855_gpio_resources),
67 		.resources = vx855_gpio_resources,
68 
69 		/* we must ignore resource conflicts, for reasons outlined in
70 		 * the vx855_gpio driver */
71 		.ignore_resource_conflicts = true,
72 	},
73 };
74 
75 static int vx855_probe(struct pci_dev *pdev,
76 				 const struct pci_device_id *id)
77 {
78 	int ret;
79 	u16 gpio_io_offset;
80 
81 	ret = pci_enable_device(pdev);
82 	if (ret)
83 		return -ENODEV;
84 
85 	pci_read_config_word(pdev, VX855_CFG_PMIO_OFFSET, &gpio_io_offset);
86 	if (!gpio_io_offset) {
87 		dev_warn(&pdev->dev,
88 			"BIOS did not assign PMIO base offset?!?\n");
89 		ret = -ENODEV;
90 		goto out;
91 	}
92 
93 	/* mask out the lowest seven bits, as they are always zero, but
94 	 * hardware returns them as 0x01 */
95 	gpio_io_offset &= 0xff80;
96 
97 	/* As the region identified here includes many non-GPIO things, we
98 	 * only work with the specific registers that concern us. */
99 	vx855_gpio_resources[0].start = gpio_io_offset + VX855_PMIO_R_GPI;
100 	vx855_gpio_resources[0].end = vx855_gpio_resources[0].start + 3;
101 	vx855_gpio_resources[1].start = gpio_io_offset + VX855_PMIO_R_GPO;
102 	vx855_gpio_resources[1].end = vx855_gpio_resources[1].start + 3;
103 
104 	ret = mfd_add_devices(&pdev->dev, -1, vx855_cells, ARRAY_SIZE(vx855_cells),
105 			NULL, 0, NULL);
106 
107 	/* we always return -ENODEV here in order to enable other
108 	 * drivers like old, not-yet-platform_device ported i2c-viapro */
109 	return -ENODEV;
110 out:
111 	pci_disable_device(pdev);
112 	return ret;
113 }
114 
115 static void vx855_remove(struct pci_dev *pdev)
116 {
117 	mfd_remove_devices(&pdev->dev);
118 	pci_disable_device(pdev);
119 }
120 
121 static const struct pci_device_id vx855_pci_tbl[] = {
122 	{ PCI_DEVICE(PCI_VENDOR_ID_VIA, PCI_DEVICE_ID_VIA_VX855) },
123 	{ 0, }
124 };
125 MODULE_DEVICE_TABLE(pci, vx855_pci_tbl);
126 
127 static struct pci_driver vx855_pci_driver = {
128 	.name		= "vx855",
129 	.id_table	= vx855_pci_tbl,
130 	.probe		= vx855_probe,
131 	.remove		= vx855_remove,
132 };
133 
134 module_pci_driver(vx855_pci_driver);
135 
136 MODULE_LICENSE("GPL");
137 MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>");
138 MODULE_DESCRIPTION("Driver for the VIA VX855 chipset");
139