Florian Fainelli | 9956d02 | 2010-03-21 01:06:09 +0100 | [diff] [blame] | 1 | /* |
| 2 | * RDC321x GPIO driver |
| 3 | * |
| 4 | * Copyright (C) 2008, Volker Weiss <dev@tintuc.de> |
| 5 | * Copyright (C) 2007-2010 Florian Fainelli <florian@openwrt.org> |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. |
| 20 | * |
| 21 | */ |
| 22 | #include <linux/module.h> |
| 23 | #include <linux/kernel.h> |
| 24 | #include <linux/init.h> |
| 25 | #include <linux/spinlock.h> |
| 26 | #include <linux/platform_device.h> |
| 27 | #include <linux/pci.h> |
| 28 | #include <linux/gpio.h> |
| 29 | #include <linux/mfd/rdc321x.h> |
Tejun Heo | 374b72e | 2010-04-02 18:24:20 +0200 | [diff] [blame] | 30 | #include <linux/slab.h> |
Florian Fainelli | 9956d02 | 2010-03-21 01:06:09 +0100 | [diff] [blame] | 31 | |
| 32 | struct rdc321x_gpio { |
| 33 | spinlock_t lock; |
| 34 | struct pci_dev *sb_pdev; |
| 35 | u32 data_reg[2]; |
| 36 | int reg1_ctrl_base; |
| 37 | int reg1_data_base; |
| 38 | int reg2_ctrl_base; |
| 39 | int reg2_data_base; |
| 40 | struct gpio_chip chip; |
| 41 | }; |
| 42 | |
| 43 | /* read GPIO pin */ |
| 44 | static int rdc_gpio_get_value(struct gpio_chip *chip, unsigned gpio) |
| 45 | { |
| 46 | struct rdc321x_gpio *gpch; |
| 47 | u32 value = 0; |
| 48 | int reg; |
| 49 | |
| 50 | gpch = container_of(chip, struct rdc321x_gpio, chip); |
| 51 | reg = gpio < 32 ? gpch->reg1_data_base : gpch->reg2_data_base; |
| 52 | |
| 53 | spin_lock(&gpch->lock); |
| 54 | pci_write_config_dword(gpch->sb_pdev, reg, |
| 55 | gpch->data_reg[gpio < 32 ? 0 : 1]); |
| 56 | pci_read_config_dword(gpch->sb_pdev, reg, &value); |
| 57 | spin_unlock(&gpch->lock); |
| 58 | |
| 59 | return (1 << (gpio & 0x1f)) & value ? 1 : 0; |
| 60 | } |
| 61 | |
| 62 | static void rdc_gpio_set_value_impl(struct gpio_chip *chip, |
| 63 | unsigned gpio, int value) |
| 64 | { |
| 65 | struct rdc321x_gpio *gpch; |
| 66 | int reg = (gpio < 32) ? 0 : 1; |
| 67 | |
| 68 | gpch = container_of(chip, struct rdc321x_gpio, chip); |
| 69 | |
| 70 | if (value) |
| 71 | gpch->data_reg[reg] |= 1 << (gpio & 0x1f); |
| 72 | else |
| 73 | gpch->data_reg[reg] &= ~(1 << (gpio & 0x1f)); |
| 74 | |
| 75 | pci_write_config_dword(gpch->sb_pdev, |
Florian Fainelli | 75907a1 | 2010-05-16 12:02:18 +0200 | [diff] [blame] | 76 | reg ? gpch->reg2_data_base : gpch->reg1_data_base, |
Florian Fainelli | 9956d02 | 2010-03-21 01:06:09 +0100 | [diff] [blame] | 77 | gpch->data_reg[reg]); |
| 78 | } |
| 79 | |
| 80 | /* set GPIO pin to value */ |
| 81 | static void rdc_gpio_set_value(struct gpio_chip *chip, |
| 82 | unsigned gpio, int value) |
| 83 | { |
| 84 | struct rdc321x_gpio *gpch; |
| 85 | |
| 86 | gpch = container_of(chip, struct rdc321x_gpio, chip); |
| 87 | spin_lock(&gpch->lock); |
| 88 | rdc_gpio_set_value_impl(chip, gpio, value); |
| 89 | spin_unlock(&gpch->lock); |
| 90 | } |
| 91 | |
| 92 | static int rdc_gpio_config(struct gpio_chip *chip, |
| 93 | unsigned gpio, int value) |
| 94 | { |
| 95 | struct rdc321x_gpio *gpch; |
| 96 | int err; |
| 97 | u32 reg; |
| 98 | |
| 99 | gpch = container_of(chip, struct rdc321x_gpio, chip); |
| 100 | |
| 101 | spin_lock(&gpch->lock); |
| 102 | err = pci_read_config_dword(gpch->sb_pdev, gpio < 32 ? |
| 103 | gpch->reg1_ctrl_base : gpch->reg2_ctrl_base, ®); |
| 104 | if (err) |
| 105 | goto unlock; |
| 106 | |
| 107 | reg |= 1 << (gpio & 0x1f); |
| 108 | |
| 109 | err = pci_write_config_dword(gpch->sb_pdev, gpio < 32 ? |
| 110 | gpch->reg1_ctrl_base : gpch->reg2_ctrl_base, reg); |
| 111 | if (err) |
| 112 | goto unlock; |
| 113 | |
| 114 | rdc_gpio_set_value_impl(chip, gpio, value); |
| 115 | |
| 116 | unlock: |
| 117 | spin_unlock(&gpch->lock); |
| 118 | |
| 119 | return err; |
| 120 | } |
| 121 | |
| 122 | /* configure GPIO pin as input */ |
| 123 | static int rdc_gpio_direction_input(struct gpio_chip *chip, unsigned gpio) |
| 124 | { |
| 125 | return rdc_gpio_config(chip, gpio, 1); |
| 126 | } |
| 127 | |
| 128 | /* |
| 129 | * Cache the initial value of both GPIO data registers |
| 130 | */ |
| 131 | static int __devinit rdc321x_gpio_probe(struct platform_device *pdev) |
| 132 | { |
| 133 | int err; |
| 134 | struct resource *r; |
| 135 | struct rdc321x_gpio *rdc321x_gpio_dev; |
| 136 | struct rdc321x_gpio_pdata *pdata; |
| 137 | |
| 138 | pdata = pdev->dev.platform_data; |
| 139 | if (!pdata) { |
| 140 | dev_err(&pdev->dev, "no platform data supplied\n"); |
| 141 | return -ENODEV; |
| 142 | } |
| 143 | |
| 144 | rdc321x_gpio_dev = kzalloc(sizeof(struct rdc321x_gpio), GFP_KERNEL); |
| 145 | if (!rdc321x_gpio_dev) { |
| 146 | dev_err(&pdev->dev, "failed to allocate private data\n"); |
| 147 | return -ENOMEM; |
| 148 | } |
| 149 | |
Florian Fainelli | 8deca39e | 2010-05-15 22:58:27 +0200 | [diff] [blame] | 150 | r = platform_get_resource_byname(pdev, IORESOURCE_IO, "gpio-reg1"); |
Florian Fainelli | 9956d02 | 2010-03-21 01:06:09 +0100 | [diff] [blame] | 151 | if (!r) { |
| 152 | dev_err(&pdev->dev, "failed to get gpio-reg1 resource\n"); |
| 153 | err = -ENODEV; |
| 154 | goto out_free; |
| 155 | } |
| 156 | |
| 157 | spin_lock_init(&rdc321x_gpio_dev->lock); |
| 158 | rdc321x_gpio_dev->sb_pdev = pdata->sb_pdev; |
| 159 | rdc321x_gpio_dev->reg1_ctrl_base = r->start; |
| 160 | rdc321x_gpio_dev->reg1_data_base = r->start + 0x4; |
| 161 | |
Florian Fainelli | 8deca39e | 2010-05-15 22:58:27 +0200 | [diff] [blame] | 162 | r = platform_get_resource_byname(pdev, IORESOURCE_IO, "gpio-reg2"); |
Florian Fainelli | 9956d02 | 2010-03-21 01:06:09 +0100 | [diff] [blame] | 163 | if (!r) { |
| 164 | dev_err(&pdev->dev, "failed to get gpio-reg2 resource\n"); |
| 165 | err = -ENODEV; |
| 166 | goto out_free; |
| 167 | } |
| 168 | |
| 169 | rdc321x_gpio_dev->reg2_ctrl_base = r->start; |
| 170 | rdc321x_gpio_dev->reg2_data_base = r->start + 0x4; |
| 171 | |
| 172 | rdc321x_gpio_dev->chip.label = "rdc321x-gpio"; |
| 173 | rdc321x_gpio_dev->chip.direction_input = rdc_gpio_direction_input; |
| 174 | rdc321x_gpio_dev->chip.direction_output = rdc_gpio_config; |
| 175 | rdc321x_gpio_dev->chip.get = rdc_gpio_get_value; |
| 176 | rdc321x_gpio_dev->chip.set = rdc_gpio_set_value; |
| 177 | rdc321x_gpio_dev->chip.base = 0; |
| 178 | rdc321x_gpio_dev->chip.ngpio = pdata->max_gpios; |
| 179 | |
| 180 | platform_set_drvdata(pdev, rdc321x_gpio_dev); |
| 181 | |
| 182 | /* This might not be, what others (BIOS, bootloader, etc.) |
| 183 | wrote to these registers before, but it's a good guess. Still |
| 184 | better than just using 0xffffffff. */ |
| 185 | err = pci_read_config_dword(rdc321x_gpio_dev->sb_pdev, |
| 186 | rdc321x_gpio_dev->reg1_data_base, |
| 187 | &rdc321x_gpio_dev->data_reg[0]); |
| 188 | if (err) |
| 189 | goto out_drvdata; |
| 190 | |
| 191 | err = pci_read_config_dword(rdc321x_gpio_dev->sb_pdev, |
| 192 | rdc321x_gpio_dev->reg2_data_base, |
| 193 | &rdc321x_gpio_dev->data_reg[1]); |
| 194 | if (err) |
| 195 | goto out_drvdata; |
| 196 | |
| 197 | dev_info(&pdev->dev, "registering %d GPIOs\n", |
| 198 | rdc321x_gpio_dev->chip.ngpio); |
| 199 | return gpiochip_add(&rdc321x_gpio_dev->chip); |
| 200 | |
| 201 | out_drvdata: |
| 202 | platform_set_drvdata(pdev, NULL); |
| 203 | out_free: |
| 204 | kfree(rdc321x_gpio_dev); |
| 205 | return err; |
| 206 | } |
| 207 | |
| 208 | static int __devexit rdc321x_gpio_remove(struct platform_device *pdev) |
| 209 | { |
| 210 | int ret; |
| 211 | struct rdc321x_gpio *rdc321x_gpio_dev = platform_get_drvdata(pdev); |
| 212 | |
| 213 | ret = gpiochip_remove(&rdc321x_gpio_dev->chip); |
| 214 | if (ret) |
| 215 | dev_err(&pdev->dev, "failed to unregister chip\n"); |
| 216 | |
| 217 | kfree(rdc321x_gpio_dev); |
| 218 | platform_set_drvdata(pdev, NULL); |
| 219 | |
| 220 | return ret; |
| 221 | } |
| 222 | |
| 223 | static struct platform_driver rdc321x_gpio_driver = { |
| 224 | .driver.name = "rdc321x-gpio", |
| 225 | .driver.owner = THIS_MODULE, |
| 226 | .probe = rdc321x_gpio_probe, |
| 227 | .remove = __devexit_p(rdc321x_gpio_remove), |
| 228 | }; |
| 229 | |
| 230 | static int __init rdc321x_gpio_init(void) |
| 231 | { |
| 232 | return platform_driver_register(&rdc321x_gpio_driver); |
| 233 | } |
| 234 | |
| 235 | static void __exit rdc321x_gpio_exit(void) |
| 236 | { |
| 237 | platform_driver_unregister(&rdc321x_gpio_driver); |
| 238 | } |
| 239 | |
| 240 | module_init(rdc321x_gpio_init); |
| 241 | module_exit(rdc321x_gpio_exit); |
| 242 | |
| 243 | MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>"); |
| 244 | MODULE_DESCRIPTION("RDC321x GPIO driver"); |
| 245 | MODULE_LICENSE("GPL"); |
| 246 | MODULE_ALIAS("platform:rdc321x-gpio"); |