| 1 | /* |
| 2 | * GE PIO2 GPIO Driver |
| 3 | * |
| 4 | * Author: Martyn Welch <martyn.welch@ge.com> |
| 5 | * Copyright 2009 GE Intelligent Platforms Embedded Systems, Inc. |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify it |
| 8 | * under the terms of the GNU General Public License as published by the |
| 9 | * Free Software Foundation; either version 2 of the License, or (at your |
| 10 | * option) any later version. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/moduleparam.h> |
| 15 | #include <linux/types.h> |
| 16 | #include <linux/kernel.h> |
| 17 | #include <linux/errno.h> |
| 18 | #include <linux/device.h> |
| 19 | #include <linux/platform_device.h> |
| 20 | #include <linux/ctype.h> |
| 21 | #include <linux/gpio.h> |
| 22 | #include <linux/slab.h> |
| 23 | #include <linux/vme.h> |
| 24 | |
| 25 | #include "vme_pio2.h" |
| 26 | |
| 27 | static const char driver_name[] = "pio2_gpio"; |
| 28 | |
| 29 | static struct pio2_card *gpio_to_pio2_card(struct gpio_chip *chip) |
| 30 | { |
| 31 | return container_of(chip, struct pio2_card, gc); |
| 32 | } |
| 33 | |
| 34 | static int pio2_gpio_get(struct gpio_chip *chip, unsigned int offset) |
| 35 | { |
| 36 | u8 reg; |
| 37 | int retval; |
| 38 | struct pio2_card *card = gpio_to_pio2_card(chip); |
| 39 | |
| 40 | if ((card->bank[PIO2_CHANNEL_BANK[offset]].config == OUTPUT) | |
| 41 | (card->bank[PIO2_CHANNEL_BANK[offset]].config == NOFIT)) { |
| 42 | |
| 43 | dev_err(&card->vdev->dev, "Channel not available as input\n"); |
| 44 | return 0; |
| 45 | } |
| 46 | |
| 47 | retval = vme_master_read(card->window, ®, 1, |
| 48 | PIO2_REGS_DATA[PIO2_CHANNEL_BANK[offset]]); |
| 49 | if (retval < 0) { |
| 50 | dev_err(&card->vdev->dev, "Unable to read from GPIO\n"); |
| 51 | return 0; |
| 52 | } |
| 53 | |
| 54 | /* |
| 55 | * Remember, input on channels configured as both input and output |
| 56 | * are inverted! |
| 57 | */ |
| 58 | if (reg & PIO2_CHANNEL_BIT[offset]) { |
| 59 | if (card->bank[PIO2_CHANNEL_BANK[offset]].config != BOTH) |
| 60 | return 0; |
| 61 | else |
| 62 | return 1; |
| 63 | } else { |
| 64 | if (card->bank[PIO2_CHANNEL_BANK[offset]].config != BOTH) |
| 65 | return 1; |
| 66 | else |
| 67 | return 0; |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | static void pio2_gpio_set(struct gpio_chip *chip, unsigned int offset, |
| 72 | int value) |
| 73 | { |
| 74 | u8 reg; |
| 75 | int retval; |
| 76 | struct pio2_card *card = gpio_to_pio2_card(chip); |
| 77 | |
| 78 | if ((card->bank[PIO2_CHANNEL_BANK[offset]].config == INPUT) | |
| 79 | (card->bank[PIO2_CHANNEL_BANK[offset]].config == NOFIT)) { |
| 80 | |
| 81 | dev_err(&card->vdev->dev, "Channel not available as output\n"); |
| 82 | return; |
| 83 | } |
| 84 | |
| 85 | if (value) |
| 86 | reg = card->bank[PIO2_CHANNEL_BANK[offset]].value | |
| 87 | PIO2_CHANNEL_BIT[offset]; |
| 88 | else |
| 89 | reg = card->bank[PIO2_CHANNEL_BANK[offset]].value & |
| 90 | ~PIO2_CHANNEL_BIT[offset]; |
| 91 | |
| 92 | retval = vme_master_write(card->window, ®, 1, |
| 93 | PIO2_REGS_DATA[PIO2_CHANNEL_BANK[offset]]); |
| 94 | if (retval < 0) { |
| 95 | dev_err(&card->vdev->dev, "Unable to write to GPIO\n"); |
| 96 | return; |
| 97 | } |
| 98 | |
| 99 | card->bank[PIO2_CHANNEL_BANK[offset]].value = reg; |
| 100 | } |
| 101 | |
| 102 | /* Directionality configured at board build - send appropriate response */ |
| 103 | static int pio2_gpio_dir_in(struct gpio_chip *chip, unsigned offset) |
| 104 | { |
| 105 | int data; |
| 106 | struct pio2_card *card = gpio_to_pio2_card(chip); |
| 107 | |
| 108 | if ((card->bank[PIO2_CHANNEL_BANK[offset]].config == OUTPUT) | |
| 109 | (card->bank[PIO2_CHANNEL_BANK[offset]].config == NOFIT)) { |
| 110 | dev_err(&card->vdev->dev, |
| 111 | "Channel directionality not configurable at runtine\n"); |
| 112 | |
| 113 | data = -EINVAL; |
| 114 | } else { |
| 115 | data = 0; |
| 116 | } |
| 117 | |
| 118 | return data; |
| 119 | } |
| 120 | |
| 121 | /* Directionality configured at board build - send appropriate response */ |
| 122 | static int pio2_gpio_dir_out(struct gpio_chip *chip, unsigned offset, int value) |
| 123 | { |
| 124 | int data; |
| 125 | struct pio2_card *card = gpio_to_pio2_card(chip); |
| 126 | |
| 127 | if ((card->bank[PIO2_CHANNEL_BANK[offset]].config == INPUT) | |
| 128 | (card->bank[PIO2_CHANNEL_BANK[offset]].config == NOFIT)) { |
| 129 | dev_err(&card->vdev->dev, |
| 130 | "Channel directionality not configurable at runtine\n"); |
| 131 | |
| 132 | data = -EINVAL; |
| 133 | } else { |
| 134 | data = 0; |
| 135 | } |
| 136 | |
| 137 | return data; |
| 138 | } |
| 139 | |
| 140 | /* |
| 141 | * We return whether this has been successful - this is used in the probe to |
| 142 | * ensure we have a valid card. |
| 143 | */ |
| 144 | int pio2_gpio_reset(struct pio2_card *card) |
| 145 | { |
| 146 | int retval = 0; |
| 147 | int i, j; |
| 148 | |
| 149 | u8 data = 0; |
| 150 | |
| 151 | /* Zero output registers */ |
| 152 | for (i = 0; i < 4; i++) { |
| 153 | retval = vme_master_write(card->window, &data, 1, |
| 154 | PIO2_REGS_DATA[i]); |
| 155 | if (retval < 0) |
| 156 | return retval; |
| 157 | card->bank[i].value = 0; |
| 158 | } |
| 159 | |
| 160 | /* Set input interrupt masks */ |
| 161 | for (i = 0; i < 4; i++) { |
| 162 | retval = vme_master_write(card->window, &data, 1, |
| 163 | PIO2_REGS_INT_MASK[i * 2]); |
| 164 | if (retval < 0) |
| 165 | return retval; |
| 166 | |
| 167 | retval = vme_master_write(card->window, &data, 1, |
| 168 | PIO2_REGS_INT_MASK[(i * 2) + 1]); |
| 169 | if (retval < 0) |
| 170 | return retval; |
| 171 | |
| 172 | for (j = 0; j < 8; j++) |
| 173 | card->bank[i].irq[j] = NONE; |
| 174 | } |
| 175 | |
| 176 | /* Ensure all I/O interrupts are cleared */ |
| 177 | for (i = 0; i < 4; i++) { |
| 178 | do { |
| 179 | retval = vme_master_read(card->window, &data, 1, |
| 180 | PIO2_REGS_INT_STAT[i]); |
| 181 | if (retval < 0) |
| 182 | return retval; |
| 183 | } while (data != 0); |
| 184 | } |
| 185 | |
| 186 | return 0; |
| 187 | } |
| 188 | |
| 189 | int __devinit pio2_gpio_init(struct pio2_card *card) |
| 190 | { |
| 191 | int retval = 0; |
| 192 | char *label; |
| 193 | |
| 194 | label = kmalloc(PIO2_NUM_CHANNELS, GFP_KERNEL); |
| 195 | if (label == NULL) { |
| 196 | dev_err(&card->vdev->dev, "Unable to allocate GPIO label\n"); |
| 197 | return -ENOMEM; |
| 198 | } |
| 199 | |
| 200 | sprintf(label, "%s@%s", driver_name, dev_name(&card->vdev->dev)); |
| 201 | card->gc.label = label; |
| 202 | |
| 203 | card->gc.ngpio = PIO2_NUM_CHANNELS; |
| 204 | /* Dynamic allocation of base */ |
| 205 | card->gc.base = -1; |
| 206 | /* Setup pointers to chip functions */ |
| 207 | card->gc.direction_input = pio2_gpio_dir_in; |
| 208 | card->gc.direction_output = pio2_gpio_dir_out; |
| 209 | card->gc.get = pio2_gpio_get; |
| 210 | card->gc.set = pio2_gpio_set; |
| 211 | |
| 212 | /* This function adds a memory mapped GPIO chip */ |
| 213 | retval = gpiochip_add(&(card->gc)); |
| 214 | if (retval) { |
| 215 | dev_err(&card->vdev->dev, "Unable to register GPIO\n"); |
| 216 | kfree(card->gc.label); |
| 217 | } |
| 218 | |
| 219 | return retval; |
| 220 | }; |
| 221 | |
| 222 | void pio2_gpio_exit(struct pio2_card *card) |
| 223 | { |
| 224 | const char *label = card->gc.label; |
| 225 | |
| 226 | if (gpiochip_remove(&(card->gc))) |
| 227 | dev_err(&card->vdev->dev, "Failed to remove GPIO"); |
| 228 | |
| 229 | kfree(label); |
| 230 | } |
| 231 | |