Commit | Line | Data |
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965dc5fc | 1 | /* |
948e78c3 | 2 | * Driver for GE FPGA based GPIO |
965dc5fc | 3 | * |
948e78c3 | 4 | * Author: Martyn Welch <martyn.welch@ge.com> |
965dc5fc | 5 | * |
948e78c3 | 6 | * 2008 (c) GE Intelligent Platforms Embedded Systems, Inc. |
965dc5fc MW |
7 | * |
8 | * This file is licensed under the terms of the GNU General Public License | |
9 | * version 2. This program is licensed "as is" without any warranty of any | |
10 | * kind, whether express or implied. | |
11 | */ | |
12 | ||
13 | /* TODO | |
14 | * | |
15 | * Configuration of output modes (totem-pole/open-drain) | |
16 | * Interrupt configuration - interrupts are always generated the FPGA relies on | |
17 | * the I/O interrupt controllers mask to stop them propergating | |
18 | */ | |
19 | ||
20 | #include <linux/kernel.h> | |
21 | #include <linux/compiler.h> | |
22 | #include <linux/init.h> | |
23 | #include <linux/io.h> | |
24 | #include <linux/of.h> | |
25 | #include <linux/of_device.h> | |
26 | #include <linux/of_platform.h> | |
27 | #include <linux/of_gpio.h> | |
28 | #include <linux/gpio.h> | |
5a0e3ad6 | 29 | #include <linux/slab.h> |
965dc5fc MW |
30 | |
31 | #define GEF_GPIO_DIRECT 0x00 | |
32 | #define GEF_GPIO_IN 0x04 | |
33 | #define GEF_GPIO_OUT 0x08 | |
34 | #define GEF_GPIO_TRIG 0x0C | |
35 | #define GEF_GPIO_POLAR_A 0x10 | |
36 | #define GEF_GPIO_POLAR_B 0x14 | |
37 | #define GEF_GPIO_INT_STAT 0x18 | |
38 | #define GEF_GPIO_OVERRUN 0x1C | |
39 | #define GEF_GPIO_MODE 0x20 | |
40 | ||
965dc5fc MW |
41 | static void _gef_gpio_set(void __iomem *reg, unsigned int offset, int value) |
42 | { | |
43 | unsigned int data; | |
44 | ||
45 | data = ioread32be(reg); | |
46 | /* value: 0=low; 1=high */ | |
47 | if (value & 0x1) | |
48 | data = data | (0x1 << offset); | |
49 | else | |
50 | data = data & ~(0x1 << offset); | |
51 | ||
52 | iowrite32be(data, reg); | |
53 | } | |
54 | ||
55 | ||
56 | static int gef_gpio_dir_in(struct gpio_chip *chip, unsigned offset) | |
57 | { | |
58 | unsigned int data; | |
59 | struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip); | |
60 | ||
61 | data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT); | |
62 | data = data | (0x1 << offset); | |
63 | iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT); | |
64 | ||
65 | return 0; | |
66 | } | |
67 | ||
68 | static int gef_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int value) | |
69 | { | |
70 | unsigned int data; | |
71 | struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip); | |
72 | ||
73 | /* Set direction before switching to input */ | |
74 | _gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value); | |
75 | ||
76 | data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT); | |
77 | data = data & ~(0x1 << offset); | |
78 | iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT); | |
79 | ||
80 | return 0; | |
81 | } | |
82 | ||
83 | static int gef_gpio_get(struct gpio_chip *chip, unsigned offset) | |
84 | { | |
85 | unsigned int data; | |
86 | int state = 0; | |
87 | struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip); | |
88 | ||
89 | data = ioread32be(mmchip->regs + GEF_GPIO_IN); | |
90 | state = (int)((data >> offset) & 0x1); | |
91 | ||
92 | return state; | |
93 | } | |
94 | ||
95 | static void gef_gpio_set(struct gpio_chip *chip, unsigned offset, int value) | |
96 | { | |
97 | struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip); | |
98 | ||
99 | _gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value); | |
100 | } | |
101 | ||
102 | static int __init gef_gpio_init(void) | |
103 | { | |
104 | struct device_node *np; | |
b1dd62f7 MW |
105 | int retval; |
106 | struct of_mm_gpio_chip *gef_gpio_chip; | |
965dc5fc MW |
107 | |
108 | for_each_compatible_node(np, NULL, "gef,sbc610-gpio") { | |
965dc5fc MW |
109 | |
110 | pr_debug("%s: Initialising GEF GPIO\n", np->full_name); | |
111 | ||
112 | /* Allocate chip structure */ | |
113 | gef_gpio_chip = kzalloc(sizeof(*gef_gpio_chip), GFP_KERNEL); | |
114 | if (!gef_gpio_chip) { | |
115 | pr_err("%s: Unable to allocate structure\n", | |
116 | np->full_name); | |
117 | continue; | |
118 | } | |
119 | ||
120 | /* Setup pointers to chip functions */ | |
121 | gef_gpio_chip->of_gc.gpio_cells = 2; | |
b1dd62f7 MW |
122 | gef_gpio_chip->of_gc.gc.ngpio = 19; |
123 | gef_gpio_chip->of_gc.gc.direction_input = gef_gpio_dir_in; | |
124 | gef_gpio_chip->of_gc.gc.direction_output = gef_gpio_dir_out; | |
125 | gef_gpio_chip->of_gc.gc.get = gef_gpio_get; | |
126 | gef_gpio_chip->of_gc.gc.set = gef_gpio_set; | |
127 | ||
128 | /* This function adds a memory mapped GPIO chip */ | |
129 | retval = of_mm_gpiochip_add(np, gef_gpio_chip); | |
130 | if (retval) { | |
131 | kfree(gef_gpio_chip); | |
132 | pr_err("%s: Unable to add GPIO\n", np->full_name); | |
133 | } | |
134 | } | |
135 | ||
136 | for_each_compatible_node(np, NULL, "gef,sbc310-gpio") { | |
137 | ||
138 | pr_debug("%s: Initialising GEF GPIO\n", np->full_name); | |
139 | ||
140 | /* Allocate chip structure */ | |
141 | gef_gpio_chip = kzalloc(sizeof(*gef_gpio_chip), GFP_KERNEL); | |
142 | if (!gef_gpio_chip) { | |
143 | pr_err("%s: Unable to allocate structure\n", | |
144 | np->full_name); | |
145 | continue; | |
146 | } | |
147 | ||
148 | /* Setup pointers to chip functions */ | |
149 | gef_gpio_chip->of_gc.gpio_cells = 2; | |
150 | gef_gpio_chip->of_gc.gc.ngpio = 6; | |
965dc5fc MW |
151 | gef_gpio_chip->of_gc.gc.direction_input = gef_gpio_dir_in; |
152 | gef_gpio_chip->of_gc.gc.direction_output = gef_gpio_dir_out; | |
153 | gef_gpio_chip->of_gc.gc.get = gef_gpio_get; | |
154 | gef_gpio_chip->of_gc.gc.set = gef_gpio_set; | |
155 | ||
156 | /* This function adds a memory mapped GPIO chip */ | |
157 | retval = of_mm_gpiochip_add(np, gef_gpio_chip); | |
158 | if (retval) { | |
159 | kfree(gef_gpio_chip); | |
160 | pr_err("%s: Unable to add GPIO\n", np->full_name); | |
161 | } | |
162 | } | |
163 | ||
164 | return 0; | |
165 | }; | |
166 | arch_initcall(gef_gpio_init); | |
167 | ||
948e78c3 MW |
168 | MODULE_DESCRIPTION("GE I/O FPGA GPIO driver"); |
169 | MODULE_AUTHOR("Martyn Welch <martyn.welch@ge.com"); | |
965dc5fc | 170 | MODULE_LICENSE("GPL"); |