1/*
2 * AppliedMicro X-Gene SoC GPIO-Standby Driver
3 *
4 * Copyright (c) 2014, Applied Micro Circuits Corporation
5 * Author: 	Tin Huynh <tnhuynh@apm.com>.
6 * 		Y Vo <yvo@apm.com>.
7 *
8 * This program is free software; you can redistribute  it and/or modify it
9 * under  the terms of  the GNU General  Public License as published by the
10 * Free Software Foundation;  either version 2 of the  License, or (at your
11 * option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
20 */
21
22#include <linux/module.h>
23#include <linux/io.h>
24#include <linux/platform_device.h>
25#include <linux/of_gpio.h>
26#include <linux/gpio.h>
27#include <linux/gpio/driver.h>
28#include <linux/basic_mmio_gpio.h>
29
30#define XGENE_MAX_GPIO_DS		22
31#define XGENE_MAX_GPIO_DS_IRQ		6
32
33#define GPIO_MASK(x)			(1U << ((x) % 32))
34
35#define MPA_GPIO_INT_LVL		0x0290
36#define MPA_GPIO_OE_ADDR		0x029c
37#define MPA_GPIO_OUT_ADDR		0x02a0
38#define MPA_GPIO_IN_ADDR 		0x02a4
39#define MPA_GPIO_SEL_LO 		0x0294
40
41/**
42 * struct xgene_gpio_sb - GPIO-Standby private data structure.
43 * @bgc:			memory-mapped GPIO controllers.
44 * @irq:			Mapping GPIO pins and interrupt number
45 * nirq:			Number of GPIO pins that supports interrupt
46 */
47struct xgene_gpio_sb {
48	struct bgpio_chip	bgc;
49	u32 *irq;
50	u32 nirq;
51};
52
53static inline struct xgene_gpio_sb *to_xgene_gpio_sb(struct gpio_chip *gc)
54{
55	struct bgpio_chip *bgc = to_bgpio_chip(gc);
56
57	return container_of(bgc, struct xgene_gpio_sb, bgc);
58}
59
60static void xgene_gpio_set_bit(struct bgpio_chip *bgc, void __iomem *reg, u32 gpio, int val)
61{
62	u32 data;
63
64	data = bgc->read_reg(reg);
65	if (val)
66		data |= GPIO_MASK(gpio);
67	else
68		data &= ~GPIO_MASK(gpio);
69	bgc->write_reg(reg, data);
70}
71
72static int apm_gpio_sb_to_irq(struct gpio_chip *gc, u32 gpio)
73{
74	struct xgene_gpio_sb *priv = to_xgene_gpio_sb(gc);
75
76	if (priv->irq[gpio])
77		return priv->irq[gpio];
78
79	return -ENXIO;
80}
81
82static int xgene_gpio_sb_probe(struct platform_device *pdev)
83{
84	struct xgene_gpio_sb *priv;
85	u32 ret, i;
86	u32 default_lines[] = {0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D};
87	struct resource *res;
88	void __iomem *regs;
89
90	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
91	if (!priv)
92		return -ENOMEM;
93
94	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
95	regs = devm_ioremap_resource(&pdev->dev, res);
96	if (IS_ERR(regs))
97		return PTR_ERR(regs);
98
99	ret = bgpio_init(&priv->bgc, &pdev->dev, 4,
100			regs + MPA_GPIO_IN_ADDR,
101			regs + MPA_GPIO_OUT_ADDR, NULL,
102			regs + MPA_GPIO_OE_ADDR, NULL, 0);
103        if (ret)
104                return ret;
105
106	priv->bgc.gc.to_irq = apm_gpio_sb_to_irq;
107	priv->bgc.gc.ngpio = XGENE_MAX_GPIO_DS;
108
109	priv->nirq = XGENE_MAX_GPIO_DS_IRQ;
110
111	priv->irq = devm_kzalloc(&pdev->dev, sizeof(u32) * XGENE_MAX_GPIO_DS,
112				   GFP_KERNEL);
113	if (!priv->irq)
114		return -ENOMEM;
115	memset(priv->irq, 0, sizeof(u32) * XGENE_MAX_GPIO_DS);
116
117	for (i = 0; i < priv->nirq; i++) {
118		priv->irq[default_lines[i]] = platform_get_irq(pdev, i);
119		xgene_gpio_set_bit(&priv->bgc, regs + MPA_GPIO_SEL_LO,
120                                   default_lines[i] * 2, 1);
121		xgene_gpio_set_bit(&priv->bgc, regs + MPA_GPIO_INT_LVL, i, 1);
122	}
123
124	platform_set_drvdata(pdev, priv);
125
126	ret = gpiochip_add(&priv->bgc.gc);
127	if (ret)
128		dev_err(&pdev->dev, "failed to register X-Gene GPIO Standby driver\n");
129	else
130		dev_info(&pdev->dev, "X-Gene GPIO Standby driver registered\n");
131
132	return ret;
133}
134
135static int xgene_gpio_sb_remove(struct platform_device *pdev)
136{
137	struct xgene_gpio_sb *priv = platform_get_drvdata(pdev);
138
139	return bgpio_remove(&priv->bgc);
140}
141
142static const struct of_device_id xgene_gpio_sb_of_match[] = {
143	{.compatible = "apm,xgene-gpio-sb", },
144	{},
145};
146MODULE_DEVICE_TABLE(of, xgene_gpio_sb_of_match);
147
148static struct platform_driver xgene_gpio_sb_driver = {
149	.driver = {
150		   .name = "xgene-gpio-sb",
151		   .of_match_table = xgene_gpio_sb_of_match,
152		   },
153	.probe = xgene_gpio_sb_probe,
154	.remove = xgene_gpio_sb_remove,
155};
156module_platform_driver(xgene_gpio_sb_driver);
157
158MODULE_AUTHOR("AppliedMicro");
159MODULE_DESCRIPTION("APM X-Gene GPIO Standby driver");
160MODULE_LICENSE("GPL");
161