tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1/*
2 * Toumaz Xenif TZ1090 PDC GPIO handling.
3 *
4 * Copyright (C) 2012-2013 Imagination Technologies Ltd.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/bitops.h>
12#include <linux/gpio.h>
13#include <linux/io.h>
14#include <linux/module.h>
15#include <linux/of_irq.h>
16#include <linux/pinctrl/consumer.h>
17#include <linux/platform_device.h>
18#include <linux/slab.h>
19#include <linux/syscore_ops.h>
20#include <asm/global_lock.h>
21
22/* Register offsets from SOC_GPIO_CONTROL0 */
23#define REG_SOC_GPIO_CONTROL0 0x00
24#define REG_SOC_GPIO_CONTROL1 0x04
25#define REG_SOC_GPIO_CONTROL2 0x08
26#define REG_SOC_GPIO_CONTROL3 0x0c
27#define REG_SOC_GPIO_STATUS 0x80
28
29/* PDC GPIOs go after normal GPIOs */
30#define GPIO_PDC_BASE 90
31#define GPIO_PDC_NGPIO 7
32
33/* Out of PDC gpios, only syswakes have irqs */
34#define GPIO_PDC_IRQ_FIRST 2
35#define GPIO_PDC_NIRQ 3
36
37/**
38 * struct tz1090_pdc_gpio - GPIO bank private data
39 * @chip: Generic GPIO chip for GPIO bank
40 * @reg: Base of registers, offset for this GPIO bank
41 * @irq: IRQ numbers for Syswake GPIOs
42 *
43 * This is the main private data for the PDC GPIO driver. It encapsulates a
44 * gpio_chip, and the callbacks for the gpio_chip can access the private data
45 * with the to_pdc() macro below.
46 */
47struct tz1090_pdc_gpio {
48 struct gpio_chip chip;
49 void __iomem *reg;
50 int irq[GPIO_PDC_NIRQ];
51};
52
53/* Register accesses into the PDC MMIO area */
54
55static inline void pdc_write(struct tz1090_pdc_gpio *priv, unsigned int reg_offs,
56 unsigned int data)
57{
58 writel(data, priv->reg + reg_offs);
59}
60
61static inline unsigned int pdc_read(struct tz1090_pdc_gpio *priv,
62 unsigned int reg_offs)
63{
64 return readl(priv->reg + reg_offs);
65}
66
67/* Generic GPIO interface */
68
69static int tz1090_pdc_gpio_direction_input(struct gpio_chip *chip,
70 unsigned int offset)
71{
72 struct tz1090_pdc_gpio *priv = gpiochip_get_data(chip);
73 u32 value;
74 int lstat;
75
76 __global_lock2(lstat);
77 value = pdc_read(priv, REG_SOC_GPIO_CONTROL1);
78 value |= BIT(offset);
79 pdc_write(priv, REG_SOC_GPIO_CONTROL1, value);
80 __global_unlock2(lstat);
81
82 return 0;
83}
84
85static int tz1090_pdc_gpio_direction_output(struct gpio_chip *chip,
86 unsigned int offset,
87 int output_value)
88{
89 struct tz1090_pdc_gpio *priv = gpiochip_get_data(chip);
90 u32 value;
91 int lstat;
92
93 __global_lock2(lstat);
94 /* EXT_POWER doesn't seem to have an output value bit */
95 if (offset < 6) {
96 value = pdc_read(priv, REG_SOC_GPIO_CONTROL0);
97 if (output_value)
98 value |= BIT(offset);
99 else
100 value &= ~BIT(offset);
101 pdc_write(priv, REG_SOC_GPIO_CONTROL0, value);
102 }
103
104 value = pdc_read(priv, REG_SOC_GPIO_CONTROL1);
105 value &= ~BIT(offset);
106 pdc_write(priv, REG_SOC_GPIO_CONTROL1, value);
107 __global_unlock2(lstat);
108
109 return 0;
110}
111
112static int tz1090_pdc_gpio_get(struct gpio_chip *chip, unsigned int offset)
113{
114 struct tz1090_pdc_gpio *priv = gpiochip_get_data(chip);
115 return !!(pdc_read(priv, REG_SOC_GPIO_STATUS) & BIT(offset));
116}
117
118static void tz1090_pdc_gpio_set(struct gpio_chip *chip, unsigned int offset,
119 int output_value)
120{
121 struct tz1090_pdc_gpio *priv = gpiochip_get_data(chip);
122 u32 value;
123 int lstat;
124
125 /* EXT_POWER doesn't seem to have an output value bit */
126 if (offset >= 6)
127 return;
128
129 __global_lock2(lstat);
130 value = pdc_read(priv, REG_SOC_GPIO_CONTROL0);
131 if (output_value)
132 value |= BIT(offset);
133 else
134 value &= ~BIT(offset);
135 pdc_write(priv, REG_SOC_GPIO_CONTROL0, value);
136 __global_unlock2(lstat);
137}
138
139static int tz1090_pdc_gpio_to_irq(struct gpio_chip *chip, unsigned int offset)
140{
141 struct tz1090_pdc_gpio *priv = gpiochip_get_data(chip);
142 unsigned int syswake = offset - GPIO_PDC_IRQ_FIRST;
143 int irq;
144
145 /* only syswakes have irqs */
146 if (syswake >= GPIO_PDC_NIRQ)
147 return -EINVAL;
148
149 irq = priv->irq[syswake];
150 if (!irq)
151 return -EINVAL;
152
153 return irq;
154}
155
156static int tz1090_pdc_gpio_probe(struct platform_device *pdev)
157{
158 struct device_node *np = pdev->dev.of_node;
159 struct resource *res_regs;
160 struct tz1090_pdc_gpio *priv;
161 unsigned int i;
162
163 if (!np) {
164 dev_err(&pdev->dev, "must be instantiated via devicetree\n");
165 return -ENOENT;
166 }
167
168 res_regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
169 if (!res_regs) {
170 dev_err(&pdev->dev, "cannot find registers resource\n");
171 return -ENOENT;
172 }
173
174 priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
175 if (!priv) {
176 dev_err(&pdev->dev, "unable to allocate driver data\n");
177 return -ENOMEM;
178 }
179
180 /* Ioremap the registers */
181 priv->reg = devm_ioremap(&pdev->dev, res_regs->start,
182 resource_size(res_regs));
183 if (!priv->reg) {
184 dev_err(&pdev->dev, "unable to ioremap registers\n");
185 return -ENOMEM;
186 }
187
188 /* Set up GPIO chip */
189 priv->chip.label = "tz1090-pdc-gpio";
190 priv->chip.parent = &pdev->dev;
191 priv->chip.direction_input = tz1090_pdc_gpio_direction_input;
192 priv->chip.direction_output = tz1090_pdc_gpio_direction_output;
193 priv->chip.get = tz1090_pdc_gpio_get;
194 priv->chip.set = tz1090_pdc_gpio_set;
195 priv->chip.free = gpiochip_generic_free;
196 priv->chip.request = gpiochip_generic_request;
197 priv->chip.to_irq = tz1090_pdc_gpio_to_irq;
198 priv->chip.of_node = np;
199
200 /* GPIO numbering */
201 priv->chip.base = GPIO_PDC_BASE;
202 priv->chip.ngpio = GPIO_PDC_NGPIO;
203
204 /* Map the syswake irqs */
205 for (i = 0; i < GPIO_PDC_NIRQ; ++i)
206 priv->irq[i] = irq_of_parse_and_map(np, i);
207
208 /* Add the GPIO bank */
209 gpiochip_add_data(&priv->chip, priv);
210
211 return 0;
212}
213
214static struct of_device_id tz1090_pdc_gpio_of_match[] = {
215 { .compatible = "img,tz1090-pdc-gpio" },
216 { },
217};
218
219static struct platform_driver tz1090_pdc_gpio_driver = {
220 .driver = {
221 .name = "tz1090-pdc-gpio",
222 .of_match_table = tz1090_pdc_gpio_of_match,
223 },
224 .probe = tz1090_pdc_gpio_probe,
225};
226
227static int __init tz1090_pdc_gpio_init(void)
228{
229 return platform_driver_register(&tz1090_pdc_gpio_driver);
230}
231subsys_initcall(tz1090_pdc_gpio_init);