Martyn Welch | 965dc5f | 2008-11-07 14:15:42 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Driver for GE Fanuc's FPGA based GPIO pins |
| 3 | * |
| 4 | * Author: Martyn Welch <martyn.welch@gefanuc.com> |
| 5 | * |
| 6 | * 2008 (c) GE Fanuc Intelligent Platforms Embedded Systems, Inc. |
| 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> |
| 29 | |
| 30 | #define GEF_GPIO_DIRECT 0x00 |
| 31 | #define GEF_GPIO_IN 0x04 |
| 32 | #define GEF_GPIO_OUT 0x08 |
| 33 | #define GEF_GPIO_TRIG 0x0C |
| 34 | #define GEF_GPIO_POLAR_A 0x10 |
| 35 | #define GEF_GPIO_POLAR_B 0x14 |
| 36 | #define GEF_GPIO_INT_STAT 0x18 |
| 37 | #define GEF_GPIO_OVERRUN 0x1C |
| 38 | #define GEF_GPIO_MODE 0x20 |
| 39 | |
Martyn Welch | 965dc5f | 2008-11-07 14:15:42 +0000 | [diff] [blame] | 40 | static void _gef_gpio_set(void __iomem *reg, unsigned int offset, int value) |
| 41 | { |
| 42 | unsigned int data; |
| 43 | |
| 44 | data = ioread32be(reg); |
| 45 | /* value: 0=low; 1=high */ |
| 46 | if (value & 0x1) |
| 47 | data = data | (0x1 << offset); |
| 48 | else |
| 49 | data = data & ~(0x1 << offset); |
| 50 | |
| 51 | iowrite32be(data, reg); |
| 52 | } |
| 53 | |
| 54 | |
| 55 | static int gef_gpio_dir_in(struct gpio_chip *chip, unsigned offset) |
| 56 | { |
| 57 | unsigned int data; |
| 58 | struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip); |
| 59 | |
| 60 | data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT); |
| 61 | data = data | (0x1 << offset); |
| 62 | iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT); |
| 63 | |
| 64 | return 0; |
| 65 | } |
| 66 | |
| 67 | static int gef_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int value) |
| 68 | { |
| 69 | unsigned int data; |
| 70 | struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip); |
| 71 | |
| 72 | /* Set direction before switching to input */ |
| 73 | _gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value); |
| 74 | |
| 75 | data = ioread32be(mmchip->regs + GEF_GPIO_DIRECT); |
| 76 | data = data & ~(0x1 << offset); |
| 77 | iowrite32be(data, mmchip->regs + GEF_GPIO_DIRECT); |
| 78 | |
| 79 | return 0; |
| 80 | } |
| 81 | |
| 82 | static int gef_gpio_get(struct gpio_chip *chip, unsigned offset) |
| 83 | { |
| 84 | unsigned int data; |
| 85 | int state = 0; |
| 86 | struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip); |
| 87 | |
| 88 | data = ioread32be(mmchip->regs + GEF_GPIO_IN); |
| 89 | state = (int)((data >> offset) & 0x1); |
| 90 | |
| 91 | return state; |
| 92 | } |
| 93 | |
| 94 | static void gef_gpio_set(struct gpio_chip *chip, unsigned offset, int value) |
| 95 | { |
| 96 | struct of_mm_gpio_chip *mmchip = to_of_mm_gpio_chip(chip); |
| 97 | |
| 98 | _gef_gpio_set(mmchip->regs + GEF_GPIO_OUT, offset, value); |
| 99 | } |
| 100 | |
| 101 | static int __init gef_gpio_init(void) |
| 102 | { |
| 103 | struct device_node *np; |
Martyn Welch | b1dd62f | 2009-01-19 11:33:34 +0000 | [diff] [blame] | 104 | int retval; |
| 105 | struct of_mm_gpio_chip *gef_gpio_chip; |
Martyn Welch | 965dc5f | 2008-11-07 14:15:42 +0000 | [diff] [blame] | 106 | |
| 107 | for_each_compatible_node(np, NULL, "gef,sbc610-gpio") { |
Martyn Welch | 965dc5f | 2008-11-07 14:15:42 +0000 | [diff] [blame] | 108 | |
| 109 | pr_debug("%s: Initialising GEF GPIO\n", np->full_name); |
| 110 | |
| 111 | /* Allocate chip structure */ |
| 112 | gef_gpio_chip = kzalloc(sizeof(*gef_gpio_chip), GFP_KERNEL); |
| 113 | if (!gef_gpio_chip) { |
| 114 | pr_err("%s: Unable to allocate structure\n", |
| 115 | np->full_name); |
| 116 | continue; |
| 117 | } |
| 118 | |
| 119 | /* Setup pointers to chip functions */ |
| 120 | gef_gpio_chip->of_gc.gpio_cells = 2; |
Martyn Welch | b1dd62f | 2009-01-19 11:33:34 +0000 | [diff] [blame] | 121 | gef_gpio_chip->of_gc.gc.ngpio = 19; |
| 122 | gef_gpio_chip->of_gc.gc.direction_input = gef_gpio_dir_in; |
| 123 | gef_gpio_chip->of_gc.gc.direction_output = gef_gpio_dir_out; |
| 124 | gef_gpio_chip->of_gc.gc.get = gef_gpio_get; |
| 125 | gef_gpio_chip->of_gc.gc.set = gef_gpio_set; |
| 126 | |
| 127 | /* This function adds a memory mapped GPIO chip */ |
| 128 | retval = of_mm_gpiochip_add(np, gef_gpio_chip); |
| 129 | if (retval) { |
| 130 | kfree(gef_gpio_chip); |
| 131 | pr_err("%s: Unable to add GPIO\n", np->full_name); |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | for_each_compatible_node(np, NULL, "gef,sbc310-gpio") { |
| 136 | |
| 137 | pr_debug("%s: Initialising GEF GPIO\n", np->full_name); |
| 138 | |
| 139 | /* Allocate chip structure */ |
| 140 | gef_gpio_chip = kzalloc(sizeof(*gef_gpio_chip), GFP_KERNEL); |
| 141 | if (!gef_gpio_chip) { |
| 142 | pr_err("%s: Unable to allocate structure\n", |
| 143 | np->full_name); |
| 144 | continue; |
| 145 | } |
| 146 | |
| 147 | /* Setup pointers to chip functions */ |
| 148 | gef_gpio_chip->of_gc.gpio_cells = 2; |
| 149 | gef_gpio_chip->of_gc.gc.ngpio = 6; |
Martyn Welch | 965dc5f | 2008-11-07 14:15:42 +0000 | [diff] [blame] | 150 | gef_gpio_chip->of_gc.gc.direction_input = gef_gpio_dir_in; |
| 151 | gef_gpio_chip->of_gc.gc.direction_output = gef_gpio_dir_out; |
| 152 | gef_gpio_chip->of_gc.gc.get = gef_gpio_get; |
| 153 | gef_gpio_chip->of_gc.gc.set = gef_gpio_set; |
| 154 | |
| 155 | /* This function adds a memory mapped GPIO chip */ |
| 156 | retval = of_mm_gpiochip_add(np, gef_gpio_chip); |
| 157 | if (retval) { |
| 158 | kfree(gef_gpio_chip); |
| 159 | pr_err("%s: Unable to add GPIO\n", np->full_name); |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | return 0; |
| 164 | }; |
| 165 | arch_initcall(gef_gpio_init); |
| 166 | |
| 167 | MODULE_DESCRIPTION("GE Fanuc I/O FPGA GPIO driver"); |
| 168 | MODULE_AUTHOR("Martyn Welch <martyn.welch@gefanuc.com"); |
| 169 | MODULE_LICENSE("GPL"); |