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Dmitry Eremin-Solenikovf942a7d2012-06-01 17:36:31 +04001/*
2 * GPIO driver for AMD 8111 south bridges
3 *
4 * Copyright (c) 2012 Dmitry Eremin-Solenikov
5 *
6 * Based on the AMD RNG driver:
7 * Copyright 2005 (c) MontaVista Software, Inc.
8 * with the majority of the code coming from:
9 *
10 * Hardware driver for the Intel/AMD/VIA Random Number Generators (RNG)
11 * (c) Copyright 2003 Red Hat Inc <jgarzik@redhat.com>
12 *
13 * derived from
14 *
15 * Hardware driver for the AMD 768 Random Number Generator (RNG)
16 * (c) Copyright 2001 Red Hat Inc
17 *
18 * derived from
19 *
20 * Hardware driver for Intel i810 Random Number Generator (RNG)
21 * Copyright 2000,2001 Jeff Garzik <jgarzik@pobox.com>
22 * Copyright 2000,2001 Philipp Rumpf <prumpf@mandrakesoft.com>
23 *
24 * This file is licensed under the terms of the GNU General Public
25 * License version 2. This program is licensed "as is" without any
26 * warranty of any kind, whether express or implied.
27 */
28#include <linux/module.h>
29#include <linux/kernel.h>
30#include <linux/gpio.h>
31#include <linux/pci.h>
32#include <linux/spinlock.h>
33
34#define PMBASE_OFFSET 0xb0
35#define PMBASE_SIZE 0x30
36
37#define AMD_REG_GPIO(i) (0x10 + (i))
38
39#define AMD_GPIO_LTCH_STS 0x40 /* Latch status, w1 */
40#define AMD_GPIO_RTIN 0x20 /* Real Time in, ro */
41#define AMD_GPIO_DEBOUNCE 0x10 /* Debounce, rw */
42#define AMD_GPIO_MODE_MASK 0x0c /* Pin Mode Select, rw */
43#define AMD_GPIO_MODE_IN 0x00
44#define AMD_GPIO_MODE_OUT 0x04
45/* Enable alternative (e.g. clkout, IRQ, etc) function of the pin */
46#define AMD_GPIO_MODE_ALTFN 0x08 /* Or 0x09 */
47#define AMD_GPIO_X_MASK 0x03 /* In/Out specific, rw */
48#define AMD_GPIO_X_IN_ACTIVEHI 0x01 /* Active High */
49#define AMD_GPIO_X_IN_LATCH 0x02 /* Latched version is selected */
50#define AMD_GPIO_X_OUT_LOW 0x00
51#define AMD_GPIO_X_OUT_HI 0x01
52#define AMD_GPIO_X_OUT_CLK0 0x02
53#define AMD_GPIO_X_OUT_CLK1 0x03
54
55/*
56 * Data for PCI driver interface
57 *
58 * This data only exists for exporting the supported
59 * PCI ids via MODULE_DEVICE_TABLE. We do not actually
60 * register a pci_driver, because someone else might one day
61 * want to register another driver on the same PCI id.
62 */
63static DEFINE_PCI_DEVICE_TABLE(pci_tbl) = {
64 { PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_8111_SMBUS), 0 },
65 { 0, }, /* terminate list */
66};
67MODULE_DEVICE_TABLE(pci, pci_tbl);
68
69struct amd_gpio {
70 struct gpio_chip chip;
71 u32 pmbase;
72 void __iomem *pm;
73 struct pci_dev *pdev;
74 spinlock_t lock; /* guards hw registers and orig table */
75 u8 orig[32];
76};
77
78#define to_agp(chip) container_of(chip, struct amd_gpio, chip)
79
80static int amd_gpio_request(struct gpio_chip *chip, unsigned offset)
81{
82 struct amd_gpio *agp = to_agp(chip);
83
84 agp->orig[offset] = ioread8(agp->pm + AMD_REG_GPIO(offset)) &
85 (AMD_GPIO_DEBOUNCE | AMD_GPIO_MODE_MASK | AMD_GPIO_X_MASK);
86
87 dev_dbg(&agp->pdev->dev, "Requested gpio %d, data %x\n", offset, agp->orig[offset]);
88
89 return 0;
90}
91
92static void amd_gpio_free(struct gpio_chip *chip, unsigned offset)
93{
94 struct amd_gpio *agp = to_agp(chip);
95
96 dev_dbg(&agp->pdev->dev, "Freed gpio %d, data %x\n", offset, agp->orig[offset]);
97
98 iowrite8(agp->orig[offset], agp->pm + AMD_REG_GPIO(offset));
99}
100
101static void amd_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
102{
103 struct amd_gpio *agp = to_agp(chip);
104 u8 temp;
105 unsigned long flags;
106
107 spin_lock_irqsave(&agp->lock, flags);
108 temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
109 temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_OUT | (value ? AMD_GPIO_X_OUT_HI : AMD_GPIO_X_OUT_LOW);
110 iowrite8(temp, agp->pm + AMD_REG_GPIO(offset));
111 spin_unlock_irqrestore(&agp->lock, flags);
112
113 dev_dbg(&agp->pdev->dev, "Setting gpio %d, value %d, reg=%02x\n", offset, !!value, temp);
114}
115
116static int amd_gpio_get(struct gpio_chip *chip, unsigned offset)
117{
118 struct amd_gpio *agp = to_agp(chip);
119 u8 temp;
120
121 temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
122
123 dev_dbg(&agp->pdev->dev, "Getting gpio %d, reg=%02x\n", offset, temp);
124
125 return (temp & AMD_GPIO_RTIN) ? 1 : 0;
126}
127
128static int amd_gpio_dirout(struct gpio_chip *chip, unsigned offset, int value)
129{
130 struct amd_gpio *agp = to_agp(chip);
131 u8 temp;
132 unsigned long flags;
133
134 spin_lock_irqsave(&agp->lock, flags);
135 temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
136 temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_OUT | (value ? AMD_GPIO_X_OUT_HI : AMD_GPIO_X_OUT_LOW);
137 iowrite8(temp, agp->pm + AMD_REG_GPIO(offset));
138 spin_unlock_irqrestore(&agp->lock, flags);
139
140 dev_dbg(&agp->pdev->dev, "Dirout gpio %d, value %d, reg=%02x\n", offset, !!value, temp);
141
142 return 0;
143}
144
145static int amd_gpio_dirin(struct gpio_chip *chip, unsigned offset)
146{
147 struct amd_gpio *agp = to_agp(chip);
148 u8 temp;
149 unsigned long flags;
150
151 spin_lock_irqsave(&agp->lock, flags);
152 temp = ioread8(agp->pm + AMD_REG_GPIO(offset));
153 temp = (temp & AMD_GPIO_DEBOUNCE) | AMD_GPIO_MODE_IN;
154 iowrite8(temp, agp->pm + AMD_REG_GPIO(offset));
155 spin_unlock_irqrestore(&agp->lock, flags);
156
157 dev_dbg(&agp->pdev->dev, "Dirin gpio %d, reg=%02x\n", offset, temp);
158
159 return 0;
160}
161
162static struct amd_gpio gp = {
163 .chip = {
164 .label = "AMD GPIO",
165 .owner = THIS_MODULE,
166 .base = -1,
167 .ngpio = 32,
168 .request = amd_gpio_request,
169 .free = amd_gpio_free,
170 .set = amd_gpio_set,
171 .get = amd_gpio_get,
172 .direction_output = amd_gpio_dirout,
173 .direction_input = amd_gpio_dirin,
174 },
175};
176
177static int __init amd_gpio_init(void)
178{
179 int err = -ENODEV;
180 struct pci_dev *pdev = NULL;
181 const struct pci_device_id *ent;
182
183
184 /* We look for our device - AMD South Bridge
185 * I don't know about a system with two such bridges,
186 * so we can assume that there is max. one device.
187 *
188 * We can't use plain pci_driver mechanism,
189 * as the device is really a multiple function device,
190 * main driver that binds to the pci_device is an smbus
191 * driver and have to find & bind to the device this way.
192 */
193 for_each_pci_dev(pdev) {
194 ent = pci_match_id(pci_tbl, pdev);
195 if (ent)
196 goto found;
197 }
198 /* Device not found. */
199 goto out;
200
201found:
202 err = pci_read_config_dword(pdev, 0x58, &gp.pmbase);
203 if (err)
204 goto out;
205 err = -EIO;
206 gp.pmbase &= 0x0000FF00;
207 if (gp.pmbase == 0)
208 goto out;
209 if (!request_region(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE, "AMD GPIO")) {
210 dev_err(&pdev->dev, "AMD GPIO region 0x%x already in use!\n",
211 gp.pmbase + PMBASE_OFFSET);
212 err = -EBUSY;
213 goto out;
214 }
215 gp.pm = ioport_map(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE);
216 gp.pdev = pdev;
217 gp.chip.dev = &pdev->dev;
218
219 spin_lock_init(&gp.lock);
220
221 printk(KERN_INFO "AMD-8111 GPIO detected\n");
222 err = gpiochip_add(&gp.chip);
223 if (err) {
224 printk(KERN_ERR "GPIO registering failed (%d)\n",
225 err);
226 release_region(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE);
227 goto out;
228 }
229out:
230 return err;
231}
232
233static void __exit amd_gpio_exit(void)
234{
235 int err = gpiochip_remove(&gp.chip);
236 WARN_ON(err);
237 ioport_unmap(gp.pm);
238 release_region(gp.pmbase + PMBASE_OFFSET, PMBASE_SIZE);
239}
240
241module_init(amd_gpio_init);
242module_exit(amd_gpio_exit);
243
244MODULE_AUTHOR("The Linux Kernel team");
245MODULE_DESCRIPTION("GPIO driver for AMD chipsets");
246MODULE_LICENSE("GPL");