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| 1 | /* |
| 2 | * Janz MODULbus VMOD-TTL GPIO Driver |
| 3 | * |
| 4 | * Copyright (c) 2010 Ira W. Snyder <iws@ovro.caltech.edu> |
| 5 | * |
| 6 | * This program is free software; you can redistribute it and/or modify it |
| 7 | * under the terms of the GNU General Public License as published by the |
| 8 | * Free Software Foundation; either version 2 of the License, or (at your |
| 9 | * option) any later version. |
| 10 | */ |
| 11 | |
| 12 | #include <linux/kernel.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/interrupt.h> |
| 16 | #include <linux/delay.h> |
| 17 | #include <linux/platform_device.h> |
| 18 | #include <linux/io.h> |
| 19 | #include <linux/gpio.h> |
| 20 | #include <linux/slab.h> |
| 21 | |
| 22 | #include <linux/mfd/janz.h> |
| 23 | |
| 24 | #define DRV_NAME "janz-ttl" |
| 25 | |
| 26 | #define PORTA_DIRECTION 0x23 |
| 27 | #define PORTB_DIRECTION 0x2B |
| 28 | #define PORTC_DIRECTION 0x06 |
| 29 | #define PORTA_IOCTL 0x24 |
| 30 | #define PORTB_IOCTL 0x2C |
| 31 | #define PORTC_IOCTL 0x07 |
| 32 | |
| 33 | #define MASTER_INT_CTL 0x00 |
| 34 | #define MASTER_CONF_CTL 0x01 |
| 35 | |
| 36 | #define CONF_PAE (1 << 2) |
| 37 | #define CONF_PBE (1 << 7) |
| 38 | #define CONF_PCE (1 << 4) |
| 39 | |
| 40 | struct ttl_control_regs { |
| 41 | __be16 portc; |
| 42 | __be16 portb; |
| 43 | __be16 porta; |
| 44 | __be16 control; |
| 45 | }; |
| 46 | |
| 47 | struct ttl_module { |
| 48 | struct gpio_chip gpio; |
| 49 | |
| 50 | /* base address of registers */ |
| 51 | struct ttl_control_regs __iomem *regs; |
| 52 | |
| 53 | u8 portc_shadow; |
| 54 | u8 portb_shadow; |
| 55 | u8 porta_shadow; |
| 56 | |
| 57 | spinlock_t lock; |
| 58 | }; |
| 59 | |
| 60 | static int ttl_get_value(struct gpio_chip *gpio, unsigned offset) |
| 61 | { |
| 62 | struct ttl_module *mod = dev_get_drvdata(gpio->dev); |
| 63 | u8 *shadow; |
| 64 | int ret; |
| 65 | |
| 66 | if (offset < 8) { |
| 67 | shadow = &mod->porta_shadow; |
| 68 | } else if (offset < 16) { |
| 69 | shadow = &mod->portb_shadow; |
| 70 | offset -= 8; |
| 71 | } else { |
| 72 | shadow = &mod->portc_shadow; |
| 73 | offset -= 16; |
| 74 | } |
| 75 | |
| 76 | spin_lock(&mod->lock); |
| 77 | ret = *shadow & (1 << offset); |
| 78 | spin_unlock(&mod->lock); |
| 79 | return ret; |
| 80 | } |
| 81 | |
| 82 | static void ttl_set_value(struct gpio_chip *gpio, unsigned offset, int value) |
| 83 | { |
| 84 | struct ttl_module *mod = dev_get_drvdata(gpio->dev); |
| 85 | void __iomem *port; |
| 86 | u8 *shadow; |
| 87 | |
| 88 | if (offset < 8) { |
| 89 | port = &mod->regs->porta; |
| 90 | shadow = &mod->porta_shadow; |
| 91 | } else if (offset < 16) { |
| 92 | port = &mod->regs->portb; |
| 93 | shadow = &mod->portb_shadow; |
| 94 | offset -= 8; |
| 95 | } else { |
| 96 | port = &mod->regs->portc; |
| 97 | shadow = &mod->portc_shadow; |
| 98 | offset -= 16; |
| 99 | } |
| 100 | |
| 101 | spin_lock(&mod->lock); |
| 102 | if (value) |
| 103 | *shadow |= (1 << offset); |
| 104 | else |
| 105 | *shadow &= ~(1 << offset); |
| 106 | |
| 107 | iowrite16be(*shadow, port); |
| 108 | spin_unlock(&mod->lock); |
| 109 | } |
| 110 | |
| 111 | static void __devinit ttl_write_reg(struct ttl_module *mod, u8 reg, u16 val) |
| 112 | { |
| 113 | iowrite16be(reg, &mod->regs->control); |
| 114 | iowrite16be(val, &mod->regs->control); |
| 115 | } |
| 116 | |
| 117 | static void __devinit ttl_setup_device(struct ttl_module *mod) |
| 118 | { |
| 119 | /* reset the device to a known state */ |
| 120 | iowrite16be(0x0000, &mod->regs->control); |
| 121 | iowrite16be(0x0001, &mod->regs->control); |
| 122 | iowrite16be(0x0000, &mod->regs->control); |
| 123 | |
| 124 | /* put all ports in open-drain mode */ |
| 125 | ttl_write_reg(mod, PORTA_IOCTL, 0x00ff); |
| 126 | ttl_write_reg(mod, PORTB_IOCTL, 0x00ff); |
| 127 | ttl_write_reg(mod, PORTC_IOCTL, 0x000f); |
| 128 | |
| 129 | /* set all ports as outputs */ |
| 130 | ttl_write_reg(mod, PORTA_DIRECTION, 0x0000); |
| 131 | ttl_write_reg(mod, PORTB_DIRECTION, 0x0000); |
| 132 | ttl_write_reg(mod, PORTC_DIRECTION, 0x0000); |
| 133 | |
| 134 | /* set all ports to drive zeroes */ |
| 135 | iowrite16be(0x0000, &mod->regs->porta); |
| 136 | iowrite16be(0x0000, &mod->regs->portb); |
| 137 | iowrite16be(0x0000, &mod->regs->portc); |
| 138 | |
| 139 | /* enable all ports */ |
| 140 | ttl_write_reg(mod, MASTER_CONF_CTL, CONF_PAE | CONF_PBE | CONF_PCE); |
| 141 | } |
| 142 | |
| 143 | static int __devinit ttl_probe(struct platform_device *pdev) |
| 144 | { |
| 145 | struct janz_platform_data *pdata; |
| 146 | struct device *dev = &pdev->dev; |
| 147 | struct ttl_module *mod; |
| 148 | struct gpio_chip *gpio; |
| 149 | struct resource *res; |
| 150 | int ret; |
| 151 | |
| 152 | pdata = pdev->dev.platform_data; |
| 153 | if (!pdata) { |
| 154 | dev_err(dev, "no platform data\n"); |
| 155 | ret = -ENXIO; |
| 156 | goto out_return; |
| 157 | } |
| 158 | |
| 159 | mod = kzalloc(sizeof(*mod), GFP_KERNEL); |
| 160 | if (!mod) { |
| 161 | dev_err(dev, "unable to allocate private data\n"); |
| 162 | ret = -ENOMEM; |
| 163 | goto out_return; |
| 164 | } |
| 165 | |
| 166 | platform_set_drvdata(pdev, mod); |
| 167 | spin_lock_init(&mod->lock); |
| 168 | |
| 169 | /* get access to the MODULbus registers for this module */ |
| 170 | res = platform_get_resource(pdev, IORESOURCE_MEM, 0); |
| 171 | if (!res) { |
| 172 | dev_err(dev, "MODULbus registers not found\n"); |
| 173 | ret = -ENODEV; |
| 174 | goto out_free_mod; |
| 175 | } |
| 176 | |
| 177 | mod->regs = ioremap(res->start, resource_size(res)); |
| 178 | if (!mod->regs) { |
| 179 | dev_err(dev, "MODULbus registers not ioremap\n"); |
| 180 | ret = -ENOMEM; |
| 181 | goto out_free_mod; |
| 182 | } |
| 183 | |
| 184 | ttl_setup_device(mod); |
| 185 | |
| 186 | /* Initialize the GPIO data structures */ |
| 187 | gpio = &mod->gpio; |
| 188 | gpio->dev = &pdev->dev; |
| 189 | gpio->label = pdev->name; |
| 190 | gpio->get = ttl_get_value; |
| 191 | gpio->set = ttl_set_value; |
| 192 | gpio->owner = THIS_MODULE; |
| 193 | |
| 194 | /* request dynamic allocation */ |
| 195 | gpio->base = -1; |
| 196 | gpio->ngpio = 20; |
| 197 | |
| 198 | ret = gpiochip_add(gpio); |
| 199 | if (ret) { |
| 200 | dev_err(dev, "unable to add GPIO chip\n"); |
| 201 | goto out_iounmap_regs; |
| 202 | } |
| 203 | |
| 204 | return 0; |
| 205 | |
| 206 | out_iounmap_regs: |
| 207 | iounmap(mod->regs); |
| 208 | out_free_mod: |
| 209 | kfree(mod); |
| 210 | out_return: |
| 211 | return ret; |
| 212 | } |
| 213 | |
| 214 | static int __devexit ttl_remove(struct platform_device *pdev) |
| 215 | { |
| 216 | struct ttl_module *mod = platform_get_drvdata(pdev); |
| 217 | struct device *dev = &pdev->dev; |
| 218 | int ret; |
| 219 | |
| 220 | ret = gpiochip_remove(&mod->gpio); |
| 221 | if (ret) { |
| 222 | dev_err(dev, "unable to remove GPIO chip\n"); |
| 223 | return ret; |
| 224 | } |
| 225 | |
| 226 | iounmap(mod->regs); |
| 227 | kfree(mod); |
| 228 | return 0; |
| 229 | } |
| 230 | |
| 231 | static struct platform_driver ttl_driver = { |
| 232 | .driver = { |
| 233 | .name = DRV_NAME, |
| 234 | .owner = THIS_MODULE, |
| 235 | }, |
| 236 | .probe = ttl_probe, |
| 237 | .remove = __devexit_p(ttl_remove), |
| 238 | }; |
| 239 | |
| 240 | module_platform_driver(ttl_driver); |
| 241 | |
| 242 | MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>"); |
| 243 | MODULE_DESCRIPTION("Janz MODULbus VMOD-TTL Driver"); |
| 244 | MODULE_LICENSE("GPL"); |
| 245 | MODULE_ALIAS("platform:janz-ttl"); |
| 246 |
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Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9
