1c103de24SGrant Likely /* 2c103de24SGrant Likely * Linux GPIOlib driver for the VIA VX855 integrated southbridge GPIO 3c103de24SGrant Likely * 4c103de24SGrant Likely * Copyright (C) 2009 VIA Technologies, Inc. 5c103de24SGrant Likely * Copyright (C) 2010 One Laptop per Child 6c103de24SGrant Likely * Author: Harald Welte <HaraldWelte@viatech.com> 7c103de24SGrant Likely * All rights reserved. 8c103de24SGrant Likely * 9c103de24SGrant Likely * This program is free software; you can redistribute it and/or 10c103de24SGrant Likely * modify it under the terms of the GNU General Public License as 11c103de24SGrant Likely * published by the Free Software Foundation; either version 2 of 12c103de24SGrant Likely * the License, or (at your option) any later version. 13c103de24SGrant Likely * 14c103de24SGrant Likely * This program is distributed in the hope that it will be useful, 15c103de24SGrant Likely * but WITHOUT ANY WARRANTY; without even the implied warranty of 16c103de24SGrant Likely * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17c103de24SGrant Likely * GNU General Public License for more details. 18c103de24SGrant Likely * 19c103de24SGrant Likely * You should have received a copy of the GNU General Public License 20c103de24SGrant Likely * along with this program; if not, write to the Free Software 21c103de24SGrant Likely * Foundation, Inc., 59 Temple Place, Suite 330, Boston, 22c103de24SGrant Likely * MA 02111-1307 USA 23c103de24SGrant Likely * 24c103de24SGrant Likely */ 25c103de24SGrant Likely 26c103de24SGrant Likely #include <linux/kernel.h> 27c103de24SGrant Likely #include <linux/module.h> 28c103de24SGrant Likely #include <linux/gpio.h> 29c103de24SGrant Likely #include <linux/slab.h> 30c103de24SGrant Likely #include <linux/device.h> 31c103de24SGrant Likely #include <linux/platform_device.h> 32c103de24SGrant Likely #include <linux/pci.h> 33c103de24SGrant Likely #include <linux/io.h> 34c103de24SGrant Likely 35c103de24SGrant Likely #define MODULE_NAME "vx855_gpio" 36c103de24SGrant Likely 37c103de24SGrant Likely /* The VX855 south bridge has the following GPIO pins: 38c103de24SGrant Likely * GPI 0...13 General Purpose Input 39c103de24SGrant Likely * GPO 0...12 General Purpose Output 40c103de24SGrant Likely * GPIO 0...14 General Purpose I/O (Open-Drain) 41c103de24SGrant Likely */ 42c103de24SGrant Likely 43c103de24SGrant Likely #define NR_VX855_GPI 14 44c103de24SGrant Likely #define NR_VX855_GPO 13 45c103de24SGrant Likely #define NR_VX855_GPIO 15 46c103de24SGrant Likely 47c103de24SGrant Likely #define NR_VX855_GPInO (NR_VX855_GPI + NR_VX855_GPO) 48c103de24SGrant Likely #define NR_VX855_GP (NR_VX855_GPI + NR_VX855_GPO + NR_VX855_GPIO) 49c103de24SGrant Likely 50c103de24SGrant Likely struct vx855_gpio { 51c103de24SGrant Likely struct gpio_chip gpio; 52c103de24SGrant Likely spinlock_t lock; 53c103de24SGrant Likely u32 io_gpi; 54c103de24SGrant Likely u32 io_gpo; 55c103de24SGrant Likely bool gpi_reserved; 56c103de24SGrant Likely bool gpo_reserved; 57c103de24SGrant Likely }; 58c103de24SGrant Likely 59c103de24SGrant Likely /* resolve a GPIx into the corresponding bit position */ 60c103de24SGrant Likely static inline u_int32_t gpi_i_bit(int i) 61c103de24SGrant Likely { 62c103de24SGrant Likely if (i < 10) 63c103de24SGrant Likely return 1 << i; 64c103de24SGrant Likely else 65c103de24SGrant Likely return 1 << (i + 14); 66c103de24SGrant Likely } 67c103de24SGrant Likely 68c103de24SGrant Likely static inline u_int32_t gpo_o_bit(int i) 69c103de24SGrant Likely { 70c103de24SGrant Likely if (i < 11) 71c103de24SGrant Likely return 1 << i; 72c103de24SGrant Likely else 73c103de24SGrant Likely return 1 << (i + 14); 74c103de24SGrant Likely } 75c103de24SGrant Likely 76c103de24SGrant Likely static inline u_int32_t gpio_i_bit(int i) 77c103de24SGrant Likely { 78c103de24SGrant Likely if (i < 14) 79c103de24SGrant Likely return 1 << (i + 10); 80c103de24SGrant Likely else 81c103de24SGrant Likely return 1 << (i + 14); 82c103de24SGrant Likely } 83c103de24SGrant Likely 84c103de24SGrant Likely static inline u_int32_t gpio_o_bit(int i) 85c103de24SGrant Likely { 86c103de24SGrant Likely if (i < 14) 87c103de24SGrant Likely return 1 << (i + 11); 88c103de24SGrant Likely else 89c103de24SGrant Likely return 1 << (i + 13); 90c103de24SGrant Likely } 91c103de24SGrant Likely 92c103de24SGrant Likely /* Mapping betwee numeric GPIO ID and the actual GPIO hardware numbering: 93c103de24SGrant Likely * 0..13 GPI 0..13 94c103de24SGrant Likely * 14..26 GPO 0..12 95c103de24SGrant Likely * 27..41 GPIO 0..14 96c103de24SGrant Likely */ 97c103de24SGrant Likely 98c103de24SGrant Likely static int vx855gpio_direction_input(struct gpio_chip *gpio, 99c103de24SGrant Likely unsigned int nr) 100c103de24SGrant Likely { 101c103de24SGrant Likely struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio); 102c103de24SGrant Likely unsigned long flags; 103c103de24SGrant Likely u_int32_t reg_out; 104c103de24SGrant Likely 105c103de24SGrant Likely /* Real GPI bits are always in input direction */ 106c103de24SGrant Likely if (nr < NR_VX855_GPI) 107c103de24SGrant Likely return 0; 108c103de24SGrant Likely 109c103de24SGrant Likely /* Real GPO bits cannot be put in output direction */ 110c103de24SGrant Likely if (nr < NR_VX855_GPInO) 111c103de24SGrant Likely return -EINVAL; 112c103de24SGrant Likely 113c103de24SGrant Likely /* Open Drain GPIO have to be set to one */ 114c103de24SGrant Likely spin_lock_irqsave(&vg->lock, flags); 115c103de24SGrant Likely reg_out = inl(vg->io_gpo); 116c103de24SGrant Likely reg_out |= gpio_o_bit(nr - NR_VX855_GPInO); 117c103de24SGrant Likely outl(reg_out, vg->io_gpo); 118c103de24SGrant Likely spin_unlock_irqrestore(&vg->lock, flags); 119c103de24SGrant Likely 120c103de24SGrant Likely return 0; 121c103de24SGrant Likely } 122c103de24SGrant Likely 123c103de24SGrant Likely static int vx855gpio_get(struct gpio_chip *gpio, unsigned int nr) 124c103de24SGrant Likely { 125c103de24SGrant Likely struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio); 126c103de24SGrant Likely u_int32_t reg_in; 127c103de24SGrant Likely int ret = 0; 128c103de24SGrant Likely 129c103de24SGrant Likely if (nr < NR_VX855_GPI) { 130c103de24SGrant Likely reg_in = inl(vg->io_gpi); 131c103de24SGrant Likely if (reg_in & gpi_i_bit(nr)) 132c103de24SGrant Likely ret = 1; 133c103de24SGrant Likely } else if (nr < NR_VX855_GPInO) { 134c103de24SGrant Likely /* GPO don't have an input bit, we need to read it 135c103de24SGrant Likely * back from the output register */ 136c103de24SGrant Likely reg_in = inl(vg->io_gpo); 137c103de24SGrant Likely if (reg_in & gpo_o_bit(nr - NR_VX855_GPI)) 138c103de24SGrant Likely ret = 1; 139c103de24SGrant Likely } else { 140c103de24SGrant Likely reg_in = inl(vg->io_gpi); 141c103de24SGrant Likely if (reg_in & gpio_i_bit(nr - NR_VX855_GPInO)) 142c103de24SGrant Likely ret = 1; 143c103de24SGrant Likely } 144c103de24SGrant Likely 145c103de24SGrant Likely return ret; 146c103de24SGrant Likely } 147c103de24SGrant Likely 148c103de24SGrant Likely static void vx855gpio_set(struct gpio_chip *gpio, unsigned int nr, 149c103de24SGrant Likely int val) 150c103de24SGrant Likely { 151c103de24SGrant Likely struct vx855_gpio *vg = container_of(gpio, struct vx855_gpio, gpio); 152c103de24SGrant Likely unsigned long flags; 153c103de24SGrant Likely u_int32_t reg_out; 154c103de24SGrant Likely 155c103de24SGrant Likely /* True GPI cannot be switched to output mode */ 156c103de24SGrant Likely if (nr < NR_VX855_GPI) 157c103de24SGrant Likely return; 158c103de24SGrant Likely 159c103de24SGrant Likely spin_lock_irqsave(&vg->lock, flags); 160c103de24SGrant Likely reg_out = inl(vg->io_gpo); 161c103de24SGrant Likely if (nr < NR_VX855_GPInO) { 162c103de24SGrant Likely if (val) 163c103de24SGrant Likely reg_out |= gpo_o_bit(nr - NR_VX855_GPI); 164c103de24SGrant Likely else 165c103de24SGrant Likely reg_out &= ~gpo_o_bit(nr - NR_VX855_GPI); 166c103de24SGrant Likely } else { 167c103de24SGrant Likely if (val) 168c103de24SGrant Likely reg_out |= gpio_o_bit(nr - NR_VX855_GPInO); 169c103de24SGrant Likely else 170c103de24SGrant Likely reg_out &= ~gpio_o_bit(nr - NR_VX855_GPInO); 171c103de24SGrant Likely } 172c103de24SGrant Likely outl(reg_out, vg->io_gpo); 173c103de24SGrant Likely spin_unlock_irqrestore(&vg->lock, flags); 174c103de24SGrant Likely } 175c103de24SGrant Likely 176c103de24SGrant Likely static int vx855gpio_direction_output(struct gpio_chip *gpio, 177c103de24SGrant Likely unsigned int nr, int val) 178c103de24SGrant Likely { 179c103de24SGrant Likely /* True GPI cannot be switched to output mode */ 180c103de24SGrant Likely if (nr < NR_VX855_GPI) 181c103de24SGrant Likely return -EINVAL; 182c103de24SGrant Likely 183c103de24SGrant Likely /* True GPO don't need to be switched to output mode, 184c103de24SGrant Likely * and GPIO are open-drain, i.e. also need no switching, 185c103de24SGrant Likely * so all we do is set the level */ 186c103de24SGrant Likely vx855gpio_set(gpio, nr, val); 187c103de24SGrant Likely 188c103de24SGrant Likely return 0; 189c103de24SGrant Likely } 190c103de24SGrant Likely 191c103de24SGrant Likely static const char *vx855gpio_names[NR_VX855_GP] = { 192c103de24SGrant Likely "VX855_GPI0", "VX855_GPI1", "VX855_GPI2", "VX855_GPI3", "VX855_GPI4", 193c103de24SGrant Likely "VX855_GPI5", "VX855_GPI6", "VX855_GPI7", "VX855_GPI8", "VX855_GPI9", 194c103de24SGrant Likely "VX855_GPI10", "VX855_GPI11", "VX855_GPI12", "VX855_GPI13", 195c103de24SGrant Likely "VX855_GPO0", "VX855_GPO1", "VX855_GPO2", "VX855_GPO3", "VX855_GPO4", 196c103de24SGrant Likely "VX855_GPO5", "VX855_GPO6", "VX855_GPO7", "VX855_GPO8", "VX855_GPO9", 197c103de24SGrant Likely "VX855_GPO10", "VX855_GPO11", "VX855_GPO12", 198c103de24SGrant Likely "VX855_GPIO0", "VX855_GPIO1", "VX855_GPIO2", "VX855_GPIO3", 199c103de24SGrant Likely "VX855_GPIO4", "VX855_GPIO5", "VX855_GPIO6", "VX855_GPIO7", 200c103de24SGrant Likely "VX855_GPIO8", "VX855_GPIO9", "VX855_GPIO10", "VX855_GPIO11", 201c103de24SGrant Likely "VX855_GPIO12", "VX855_GPIO13", "VX855_GPIO14" 202c103de24SGrant Likely }; 203c103de24SGrant Likely 204c103de24SGrant Likely static void vx855gpio_gpio_setup(struct vx855_gpio *vg) 205c103de24SGrant Likely { 206c103de24SGrant Likely struct gpio_chip *c = &vg->gpio; 207c103de24SGrant Likely 208c103de24SGrant Likely c->label = "VX855 South Bridge"; 209c103de24SGrant Likely c->owner = THIS_MODULE; 210c103de24SGrant Likely c->direction_input = vx855gpio_direction_input; 211c103de24SGrant Likely c->direction_output = vx855gpio_direction_output; 212c103de24SGrant Likely c->get = vx855gpio_get; 213c103de24SGrant Likely c->set = vx855gpio_set; 214c103de24SGrant Likely c->dbg_show = NULL; 215c103de24SGrant Likely c->base = 0; 216c103de24SGrant Likely c->ngpio = NR_VX855_GP; 217c103de24SGrant Likely c->can_sleep = 0; 218c103de24SGrant Likely c->names = vx855gpio_names; 219c103de24SGrant Likely } 220c103de24SGrant Likely 221c103de24SGrant Likely /* This platform device is ordinarily registered by the vx855 mfd driver */ 222c103de24SGrant Likely static __devinit int vx855gpio_probe(struct platform_device *pdev) 223c103de24SGrant Likely { 224c103de24SGrant Likely struct resource *res_gpi; 225c103de24SGrant Likely struct resource *res_gpo; 226c103de24SGrant Likely struct vx855_gpio *vg; 227c103de24SGrant Likely int ret; 228c103de24SGrant Likely 229c103de24SGrant Likely res_gpi = platform_get_resource(pdev, IORESOURCE_IO, 0); 230c103de24SGrant Likely res_gpo = platform_get_resource(pdev, IORESOURCE_IO, 1); 231c103de24SGrant Likely if (!res_gpi || !res_gpo) 232c103de24SGrant Likely return -EBUSY; 233c103de24SGrant Likely 234c103de24SGrant Likely vg = kzalloc(sizeof(*vg), GFP_KERNEL); 235c103de24SGrant Likely if (!vg) 236c103de24SGrant Likely return -ENOMEM; 237c103de24SGrant Likely 238c103de24SGrant Likely platform_set_drvdata(pdev, vg); 239c103de24SGrant Likely 240c103de24SGrant Likely dev_info(&pdev->dev, "found VX855 GPIO controller\n"); 241c103de24SGrant Likely vg->io_gpi = res_gpi->start; 242c103de24SGrant Likely vg->io_gpo = res_gpo->start; 243c103de24SGrant Likely spin_lock_init(&vg->lock); 244c103de24SGrant Likely 245c103de24SGrant Likely /* 246c103de24SGrant Likely * A single byte is used to control various GPIO ports on the VX855, 247c103de24SGrant Likely * and in the case of the OLPC XO-1.5, some of those ports are used 248c103de24SGrant Likely * for switches that are interpreted and exposed through ACPI. ACPI 249c103de24SGrant Likely * will have reserved the region, so our own reservation will not 250c103de24SGrant Likely * succeed. Ignore and continue. 251c103de24SGrant Likely */ 252c103de24SGrant Likely 253c103de24SGrant Likely if (!request_region(res_gpi->start, resource_size(res_gpi), 254c103de24SGrant Likely MODULE_NAME "_gpi")) 255c103de24SGrant Likely dev_warn(&pdev->dev, 256c103de24SGrant Likely "GPI I/O resource busy, probably claimed by ACPI\n"); 257c103de24SGrant Likely else 258c103de24SGrant Likely vg->gpi_reserved = true; 259c103de24SGrant Likely 260c103de24SGrant Likely if (!request_region(res_gpo->start, resource_size(res_gpo), 261c103de24SGrant Likely MODULE_NAME "_gpo")) 262c103de24SGrant Likely dev_warn(&pdev->dev, 263c103de24SGrant Likely "GPO I/O resource busy, probably claimed by ACPI\n"); 264c103de24SGrant Likely else 265c103de24SGrant Likely vg->gpo_reserved = true; 266c103de24SGrant Likely 267c103de24SGrant Likely vx855gpio_gpio_setup(vg); 268c103de24SGrant Likely 269c103de24SGrant Likely ret = gpiochip_add(&vg->gpio); 270c103de24SGrant Likely if (ret) { 271c103de24SGrant Likely dev_err(&pdev->dev, "failed to register GPIOs\n"); 272c103de24SGrant Likely goto out_release; 273c103de24SGrant Likely } 274c103de24SGrant Likely 275c103de24SGrant Likely return 0; 276c103de24SGrant Likely 277c103de24SGrant Likely out_release: 278c103de24SGrant Likely if (vg->gpi_reserved) 279c103de24SGrant Likely release_region(res_gpi->start, resource_size(res_gpi)); 280c103de24SGrant Likely if (vg->gpo_reserved) 281c103de24SGrant Likely release_region(res_gpi->start, resource_size(res_gpo)); 282c103de24SGrant Likely platform_set_drvdata(pdev, NULL); 283c103de24SGrant Likely kfree(vg); 284c103de24SGrant Likely return ret; 285c103de24SGrant Likely } 286c103de24SGrant Likely 287c103de24SGrant Likely static int __devexit vx855gpio_remove(struct platform_device *pdev) 288c103de24SGrant Likely { 289c103de24SGrant Likely struct vx855_gpio *vg = platform_get_drvdata(pdev); 290c103de24SGrant Likely struct resource *res; 291c103de24SGrant Likely 292c103de24SGrant Likely if (gpiochip_remove(&vg->gpio)) 293c103de24SGrant Likely dev_err(&pdev->dev, "unable to remove gpio_chip?\n"); 294c103de24SGrant Likely 295c103de24SGrant Likely if (vg->gpi_reserved) { 296c103de24SGrant Likely res = platform_get_resource(pdev, IORESOURCE_IO, 0); 297c103de24SGrant Likely release_region(res->start, resource_size(res)); 298c103de24SGrant Likely } 299c103de24SGrant Likely if (vg->gpo_reserved) { 300c103de24SGrant Likely res = platform_get_resource(pdev, IORESOURCE_IO, 1); 301c103de24SGrant Likely release_region(res->start, resource_size(res)); 302c103de24SGrant Likely } 303c103de24SGrant Likely 304c103de24SGrant Likely platform_set_drvdata(pdev, NULL); 305c103de24SGrant Likely kfree(vg); 306c103de24SGrant Likely return 0; 307c103de24SGrant Likely } 308c103de24SGrant Likely 309c103de24SGrant Likely static struct platform_driver vx855gpio_driver = { 310c103de24SGrant Likely .driver = { 311c103de24SGrant Likely .name = MODULE_NAME, 312c103de24SGrant Likely .owner = THIS_MODULE, 313c103de24SGrant Likely }, 314c103de24SGrant Likely .probe = vx855gpio_probe, 315c103de24SGrant Likely .remove = __devexit_p(vx855gpio_remove), 316c103de24SGrant Likely }; 317c103de24SGrant Likely 3186f61415eSMark Brown module_platform_driver(vx855gpio_driver); 319c103de24SGrant Likely 320c103de24SGrant Likely MODULE_LICENSE("GPL"); 321c103de24SGrant Likely MODULE_AUTHOR("Harald Welte <HaraldWelte@viatech.com>"); 322c103de24SGrant Likely MODULE_DESCRIPTION("GPIO driver for the VIA VX855 chipset"); 323c103de24SGrant Likely MODULE_ALIAS("platform:vx855_gpio"); 324