16596e59eSSudip Mukherjee /* 26596e59eSSudip Mukherjee * GPIO driver for Exar XR17V35X chip 36596e59eSSudip Mukherjee * 46596e59eSSudip Mukherjee * Copyright (C) 2015 Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> 56596e59eSSudip Mukherjee * 66596e59eSSudip Mukherjee * This program is free software; you can redistribute it and/or modify 76596e59eSSudip Mukherjee * it under the terms of the GNU General Public License version 2 as 86596e59eSSudip Mukherjee * published by the Free Software Foundation. 96596e59eSSudip Mukherjee */ 106596e59eSSudip Mukherjee #include <linux/bitops.h> 116596e59eSSudip Mukherjee #include <linux/device.h> 126596e59eSSudip Mukherjee #include <linux/gpio/driver.h> 136596e59eSSudip Mukherjee #include <linux/init.h> 146596e59eSSudip Mukherjee #include <linux/kernel.h> 156596e59eSSudip Mukherjee #include <linux/module.h> 166596e59eSSudip Mukherjee #include <linux/pci.h> 176596e59eSSudip Mukherjee #include <linux/platform_device.h> 186596e59eSSudip Mukherjee 196596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOLVL_LO 0x90 206596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOSEL_LO 0x93 216596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOLVL_HI 0x96 226596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOSEL_HI 0x99 236596e59eSSudip Mukherjee 246596e59eSSudip Mukherjee #define DRIVER_NAME "gpio_exar" 256596e59eSSudip Mukherjee 266596e59eSSudip Mukherjee static DEFINE_IDA(ida_index); 276596e59eSSudip Mukherjee 286596e59eSSudip Mukherjee struct exar_gpio_chip { 296596e59eSSudip Mukherjee struct gpio_chip gpio_chip; 306596e59eSSudip Mukherjee struct mutex lock; 316596e59eSSudip Mukherjee int index; 326596e59eSSudip Mukherjee void __iomem *regs; 336596e59eSSudip Mukherjee char name[20]; 34380b1e2fSJan Kiszka unsigned int first_pin; 356596e59eSSudip Mukherjee }; 366596e59eSSudip Mukherjee 376596e59eSSudip Mukherjee static void exar_update(struct gpio_chip *chip, unsigned int reg, int val, 386596e59eSSudip Mukherjee unsigned int offset) 396596e59eSSudip Mukherjee { 406596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 416596e59eSSudip Mukherjee int temp; 426596e59eSSudip Mukherjee 436596e59eSSudip Mukherjee mutex_lock(&exar_gpio->lock); 446596e59eSSudip Mukherjee temp = readb(exar_gpio->regs + reg); 456596e59eSSudip Mukherjee temp &= ~BIT(offset); 466596e59eSSudip Mukherjee if (val) 476596e59eSSudip Mukherjee temp |= BIT(offset); 486596e59eSSudip Mukherjee writeb(temp, exar_gpio->regs + reg); 496596e59eSSudip Mukherjee mutex_unlock(&exar_gpio->lock); 506596e59eSSudip Mukherjee } 516596e59eSSudip Mukherjee 526596e59eSSudip Mukherjee static int exar_set_direction(struct gpio_chip *chip, int direction, 536596e59eSSudip Mukherjee unsigned int offset) 546596e59eSSudip Mukherjee { 55380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 56380b1e2fSJan Kiszka unsigned int addr = (offset + exar_gpio->first_pin) / 8 ? 57380b1e2fSJan Kiszka EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO; 58380b1e2fSJan Kiszka unsigned int bit = (offset + exar_gpio->first_pin) % 8; 596596e59eSSudip Mukherjee 60380b1e2fSJan Kiszka exar_update(chip, addr, direction, bit); 616596e59eSSudip Mukherjee return 0; 626596e59eSSudip Mukherjee } 636596e59eSSudip Mukherjee 646596e59eSSudip Mukherjee static int exar_get(struct gpio_chip *chip, unsigned int reg) 656596e59eSSudip Mukherjee { 666596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 676596e59eSSudip Mukherjee int value; 686596e59eSSudip Mukherjee 696596e59eSSudip Mukherjee mutex_lock(&exar_gpio->lock); 706596e59eSSudip Mukherjee value = readb(exar_gpio->regs + reg); 716596e59eSSudip Mukherjee mutex_unlock(&exar_gpio->lock); 726596e59eSSudip Mukherjee 737f45a875SJan Kiszka return value; 746596e59eSSudip Mukherjee } 756596e59eSSudip Mukherjee 766596e59eSSudip Mukherjee static int exar_get_direction(struct gpio_chip *chip, unsigned int offset) 776596e59eSSudip Mukherjee { 78380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 79380b1e2fSJan Kiszka unsigned int addr = (offset + exar_gpio->first_pin) / 8 ? 80380b1e2fSJan Kiszka EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO; 81380b1e2fSJan Kiszka unsigned int bit = (offset + exar_gpio->first_pin) % 8; 826596e59eSSudip Mukherjee 83380b1e2fSJan Kiszka return !!(exar_get(chip, addr) & BIT(bit)); 846596e59eSSudip Mukherjee } 856596e59eSSudip Mukherjee 866596e59eSSudip Mukherjee static int exar_get_value(struct gpio_chip *chip, unsigned int offset) 876596e59eSSudip Mukherjee { 88380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 89380b1e2fSJan Kiszka unsigned int addr = (offset + exar_gpio->first_pin) / 8 ? 90380b1e2fSJan Kiszka EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO; 91380b1e2fSJan Kiszka unsigned int bit = (offset + exar_gpio->first_pin) % 8; 926596e59eSSudip Mukherjee 93380b1e2fSJan Kiszka return !!(exar_get(chip, addr) & BIT(bit)); 946596e59eSSudip Mukherjee } 956596e59eSSudip Mukherjee 966596e59eSSudip Mukherjee static void exar_set_value(struct gpio_chip *chip, unsigned int offset, 976596e59eSSudip Mukherjee int value) 986596e59eSSudip Mukherjee { 99380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 100380b1e2fSJan Kiszka unsigned int addr = (offset + exar_gpio->first_pin) / 8 ? 101380b1e2fSJan Kiszka EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO; 102380b1e2fSJan Kiszka unsigned int bit = (offset + exar_gpio->first_pin) % 8; 1036596e59eSSudip Mukherjee 104380b1e2fSJan Kiszka exar_update(chip, addr, value, bit); 1056596e59eSSudip Mukherjee } 1066596e59eSSudip Mukherjee 107eddeae07SAxel Lin static int exar_direction_output(struct gpio_chip *chip, unsigned int offset, 108eddeae07SAxel Lin int value) 109eddeae07SAxel Lin { 110eddeae07SAxel Lin exar_set_value(chip, offset, value); 111eddeae07SAxel Lin return exar_set_direction(chip, 0, offset); 112eddeae07SAxel Lin } 113eddeae07SAxel Lin 114eddeae07SAxel Lin static int exar_direction_input(struct gpio_chip *chip, unsigned int offset) 115eddeae07SAxel Lin { 116eddeae07SAxel Lin return exar_set_direction(chip, 1, offset); 117eddeae07SAxel Lin } 118eddeae07SAxel Lin 1196596e59eSSudip Mukherjee static int gpio_exar_probe(struct platform_device *pdev) 1206596e59eSSudip Mukherjee { 121d3936d74SJan Kiszka struct pci_dev *pcidev = to_pci_dev(pdev->dev.parent); 1226596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio; 123380b1e2fSJan Kiszka u32 first_pin, ngpios; 1246596e59eSSudip Mukherjee void __iomem *p; 1256596e59eSSudip Mukherjee int index, ret; 1266596e59eSSudip Mukherjee 1276596e59eSSudip Mukherjee /* 1288847f5f9SJan Kiszka * The UART driver must have mapped region 0 prior to registering this 1298847f5f9SJan Kiszka * device - use it. 1306596e59eSSudip Mukherjee */ 1318847f5f9SJan Kiszka p = pcim_iomap_table(pcidev)[0]; 1326596e59eSSudip Mukherjee if (!p) 1336596e59eSSudip Mukherjee return -ENOMEM; 1346596e59eSSudip Mukherjee 135a589e211SJan Kiszka ret = device_property_read_u32(&pdev->dev, "exar,first-pin", 136380b1e2fSJan Kiszka &first_pin); 137380b1e2fSJan Kiszka if (ret) 138380b1e2fSJan Kiszka return ret; 139380b1e2fSJan Kiszka 140380b1e2fSJan Kiszka ret = device_property_read_u32(&pdev->dev, "ngpios", &ngpios); 141380b1e2fSJan Kiszka if (ret) 142380b1e2fSJan Kiszka return ret; 143380b1e2fSJan Kiszka 1445dab5872SJan Kiszka exar_gpio = devm_kzalloc(&pdev->dev, sizeof(*exar_gpio), GFP_KERNEL); 1456596e59eSSudip Mukherjee if (!exar_gpio) 1466596e59eSSudip Mukherjee return -ENOMEM; 1476596e59eSSudip Mukherjee 1486596e59eSSudip Mukherjee mutex_init(&exar_gpio->lock); 1496596e59eSSudip Mukherjee 1506596e59eSSudip Mukherjee index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL); 1516596e59eSSudip Mukherjee 1526596e59eSSudip Mukherjee sprintf(exar_gpio->name, "exar_gpio%d", index); 1536596e59eSSudip Mukherjee exar_gpio->gpio_chip.label = exar_gpio->name; 1544076cf08SJan Kiszka exar_gpio->gpio_chip.parent = &pdev->dev; 1556596e59eSSudip Mukherjee exar_gpio->gpio_chip.direction_output = exar_direction_output; 1566596e59eSSudip Mukherjee exar_gpio->gpio_chip.direction_input = exar_direction_input; 1576596e59eSSudip Mukherjee exar_gpio->gpio_chip.get_direction = exar_get_direction; 1586596e59eSSudip Mukherjee exar_gpio->gpio_chip.get = exar_get_value; 1596596e59eSSudip Mukherjee exar_gpio->gpio_chip.set = exar_set_value; 1606596e59eSSudip Mukherjee exar_gpio->gpio_chip.base = -1; 161380b1e2fSJan Kiszka exar_gpio->gpio_chip.ngpio = ngpios; 1626596e59eSSudip Mukherjee exar_gpio->regs = p; 1636596e59eSSudip Mukherjee exar_gpio->index = index; 164380b1e2fSJan Kiszka exar_gpio->first_pin = first_pin; 1656596e59eSSudip Mukherjee 1665dab5872SJan Kiszka ret = devm_gpiochip_add_data(&pdev->dev, 1676596e59eSSudip Mukherjee &exar_gpio->gpio_chip, exar_gpio); 1686596e59eSSudip Mukherjee if (ret) 1696596e59eSSudip Mukherjee goto err_destroy; 1706596e59eSSudip Mukherjee 1716596e59eSSudip Mukherjee platform_set_drvdata(pdev, exar_gpio); 1726596e59eSSudip Mukherjee 1736596e59eSSudip Mukherjee return 0; 1746596e59eSSudip Mukherjee 1756596e59eSSudip Mukherjee err_destroy: 1766596e59eSSudip Mukherjee ida_simple_remove(&ida_index, index); 1776596e59eSSudip Mukherjee mutex_destroy(&exar_gpio->lock); 1786596e59eSSudip Mukherjee return ret; 1796596e59eSSudip Mukherjee } 1806596e59eSSudip Mukherjee 1816596e59eSSudip Mukherjee static int gpio_exar_remove(struct platform_device *pdev) 1826596e59eSSudip Mukherjee { 1836596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio = platform_get_drvdata(pdev); 1846596e59eSSudip Mukherjee 1856596e59eSSudip Mukherjee ida_simple_remove(&ida_index, exar_gpio->index); 1866596e59eSSudip Mukherjee mutex_destroy(&exar_gpio->lock); 1876596e59eSSudip Mukherjee 1886596e59eSSudip Mukherjee return 0; 1896596e59eSSudip Mukherjee } 1906596e59eSSudip Mukherjee 1916596e59eSSudip Mukherjee static struct platform_driver gpio_exar_driver = { 1926596e59eSSudip Mukherjee .probe = gpio_exar_probe, 1936596e59eSSudip Mukherjee .remove = gpio_exar_remove, 1946596e59eSSudip Mukherjee .driver = { 1956596e59eSSudip Mukherjee .name = DRIVER_NAME, 1966596e59eSSudip Mukherjee }, 1976596e59eSSudip Mukherjee }; 1986596e59eSSudip Mukherjee 1996596e59eSSudip Mukherjee module_platform_driver(gpio_exar_driver); 2006596e59eSSudip Mukherjee 2016596e59eSSudip Mukherjee MODULE_ALIAS("platform:" DRIVER_NAME); 2026596e59eSSudip Mukherjee MODULE_DESCRIPTION("Exar GPIO driver"); 2036596e59eSSudip Mukherjee MODULE_AUTHOR("Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>"); 2046596e59eSSudip Mukherjee MODULE_LICENSE("GPL"); 205