1d2912cb1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 26596e59eSSudip Mukherjee /* 36596e59eSSudip Mukherjee * GPIO driver for Exar XR17V35X chip 46596e59eSSudip Mukherjee * 56596e59eSSudip Mukherjee * Copyright (C) 2015 Sudip Mukherjee <sudip.mukherjee@codethink.co.uk> 66596e59eSSudip Mukherjee */ 7*1bfaf129SBartosz Golaszewski 86596e59eSSudip Mukherjee #include <linux/bitops.h> 96596e59eSSudip Mukherjee #include <linux/device.h> 106596e59eSSudip Mukherjee #include <linux/gpio/driver.h> 116596e59eSSudip Mukherjee #include <linux/init.h> 126596e59eSSudip Mukherjee #include <linux/kernel.h> 136596e59eSSudip Mukherjee #include <linux/module.h> 146596e59eSSudip Mukherjee #include <linux/pci.h> 156596e59eSSudip Mukherjee #include <linux/platform_device.h> 166596e59eSSudip Mukherjee 176596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOLVL_LO 0x90 186596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOSEL_LO 0x93 196596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOLVL_HI 0x96 206596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOSEL_HI 0x99 216596e59eSSudip Mukherjee 226596e59eSSudip Mukherjee #define DRIVER_NAME "gpio_exar" 236596e59eSSudip Mukherjee 246596e59eSSudip Mukherjee static DEFINE_IDA(ida_index); 256596e59eSSudip Mukherjee 266596e59eSSudip Mukherjee struct exar_gpio_chip { 276596e59eSSudip Mukherjee struct gpio_chip gpio_chip; 286596e59eSSudip Mukherjee struct mutex lock; 296596e59eSSudip Mukherjee int index; 306596e59eSSudip Mukherjee void __iomem *regs; 316596e59eSSudip Mukherjee char name[20]; 32380b1e2fSJan Kiszka unsigned int first_pin; 336596e59eSSudip Mukherjee }; 346596e59eSSudip Mukherjee 356596e59eSSudip Mukherjee static void exar_update(struct gpio_chip *chip, unsigned int reg, int val, 366596e59eSSudip Mukherjee unsigned int offset) 376596e59eSSudip Mukherjee { 386596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 396596e59eSSudip Mukherjee int temp; 406596e59eSSudip Mukherjee 416596e59eSSudip Mukherjee mutex_lock(&exar_gpio->lock); 426596e59eSSudip Mukherjee temp = readb(exar_gpio->regs + reg); 436596e59eSSudip Mukherjee temp &= ~BIT(offset); 446596e59eSSudip Mukherjee if (val) 456596e59eSSudip Mukherjee temp |= BIT(offset); 466596e59eSSudip Mukherjee writeb(temp, exar_gpio->regs + reg); 476596e59eSSudip Mukherjee mutex_unlock(&exar_gpio->lock); 486596e59eSSudip Mukherjee } 496596e59eSSudip Mukherjee 506596e59eSSudip Mukherjee static int exar_set_direction(struct gpio_chip *chip, int direction, 516596e59eSSudip Mukherjee unsigned int offset) 526596e59eSSudip Mukherjee { 53380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 54380b1e2fSJan Kiszka unsigned int addr = (offset + exar_gpio->first_pin) / 8 ? 55380b1e2fSJan Kiszka EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO; 56380b1e2fSJan Kiszka unsigned int bit = (offset + exar_gpio->first_pin) % 8; 576596e59eSSudip Mukherjee 58380b1e2fSJan Kiszka exar_update(chip, addr, direction, bit); 596596e59eSSudip Mukherjee return 0; 606596e59eSSudip Mukherjee } 616596e59eSSudip Mukherjee 626596e59eSSudip Mukherjee static int exar_get(struct gpio_chip *chip, unsigned int reg) 636596e59eSSudip Mukherjee { 646596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 656596e59eSSudip Mukherjee int value; 666596e59eSSudip Mukherjee 676596e59eSSudip Mukherjee mutex_lock(&exar_gpio->lock); 686596e59eSSudip Mukherjee value = readb(exar_gpio->regs + reg); 696596e59eSSudip Mukherjee mutex_unlock(&exar_gpio->lock); 706596e59eSSudip Mukherjee 717f45a875SJan Kiszka return value; 726596e59eSSudip Mukherjee } 736596e59eSSudip Mukherjee 746596e59eSSudip Mukherjee static int exar_get_direction(struct gpio_chip *chip, unsigned int offset) 756596e59eSSudip Mukherjee { 76380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 77380b1e2fSJan Kiszka unsigned int addr = (offset + exar_gpio->first_pin) / 8 ? 78380b1e2fSJan Kiszka EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO; 79380b1e2fSJan Kiszka unsigned int bit = (offset + exar_gpio->first_pin) % 8; 806596e59eSSudip Mukherjee 81e42615ecSMatti Vaittinen if (exar_get(chip, addr) & BIT(bit)) 82e42615ecSMatti Vaittinen return GPIO_LINE_DIRECTION_IN; 83e42615ecSMatti Vaittinen 84e42615ecSMatti Vaittinen return GPIO_LINE_DIRECTION_OUT; 856596e59eSSudip Mukherjee } 866596e59eSSudip Mukherjee 876596e59eSSudip Mukherjee static int exar_get_value(struct gpio_chip *chip, unsigned int offset) 886596e59eSSudip Mukherjee { 89380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 90380b1e2fSJan Kiszka unsigned int addr = (offset + exar_gpio->first_pin) / 8 ? 91380b1e2fSJan Kiszka EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO; 92380b1e2fSJan Kiszka unsigned int bit = (offset + exar_gpio->first_pin) % 8; 936596e59eSSudip Mukherjee 94380b1e2fSJan Kiszka return !!(exar_get(chip, addr) & BIT(bit)); 956596e59eSSudip Mukherjee } 966596e59eSSudip Mukherjee 976596e59eSSudip Mukherjee static void exar_set_value(struct gpio_chip *chip, unsigned int offset, 986596e59eSSudip Mukherjee int value) 996596e59eSSudip Mukherjee { 100380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 101380b1e2fSJan Kiszka unsigned int addr = (offset + exar_gpio->first_pin) / 8 ? 102380b1e2fSJan Kiszka EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO; 103380b1e2fSJan Kiszka unsigned int bit = (offset + exar_gpio->first_pin) % 8; 1046596e59eSSudip Mukherjee 105380b1e2fSJan Kiszka exar_update(chip, addr, value, bit); 1066596e59eSSudip Mukherjee } 1076596e59eSSudip Mukherjee 108eddeae07SAxel Lin static int exar_direction_output(struct gpio_chip *chip, unsigned int offset, 109eddeae07SAxel Lin int value) 110eddeae07SAxel Lin { 111eddeae07SAxel Lin exar_set_value(chip, offset, value); 112eddeae07SAxel Lin return exar_set_direction(chip, 0, offset); 113eddeae07SAxel Lin } 114eddeae07SAxel Lin 115eddeae07SAxel Lin static int exar_direction_input(struct gpio_chip *chip, unsigned int offset) 116eddeae07SAxel Lin { 117eddeae07SAxel Lin return exar_set_direction(chip, 1, offset); 118eddeae07SAxel Lin } 119eddeae07SAxel Lin 1206596e59eSSudip Mukherjee static int gpio_exar_probe(struct platform_device *pdev) 1216596e59eSSudip Mukherjee { 122d3936d74SJan Kiszka struct pci_dev *pcidev = to_pci_dev(pdev->dev.parent); 1236596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio; 124380b1e2fSJan Kiszka u32 first_pin, ngpios; 1256596e59eSSudip Mukherjee void __iomem *p; 1266596e59eSSudip Mukherjee int index, ret; 1276596e59eSSudip Mukherjee 1286596e59eSSudip Mukherjee /* 1298847f5f9SJan Kiszka * The UART driver must have mapped region 0 prior to registering this 1308847f5f9SJan Kiszka * device - use it. 1316596e59eSSudip Mukherjee */ 1328847f5f9SJan Kiszka p = pcim_iomap_table(pcidev)[0]; 1336596e59eSSudip Mukherjee if (!p) 1346596e59eSSudip Mukherjee return -ENOMEM; 1356596e59eSSudip Mukherjee 136a589e211SJan Kiszka ret = device_property_read_u32(&pdev->dev, "exar,first-pin", 137380b1e2fSJan Kiszka &first_pin); 138380b1e2fSJan Kiszka if (ret) 139380b1e2fSJan Kiszka return ret; 140380b1e2fSJan Kiszka 141380b1e2fSJan Kiszka ret = device_property_read_u32(&pdev->dev, "ngpios", &ngpios); 142380b1e2fSJan Kiszka if (ret) 143380b1e2fSJan Kiszka return ret; 144380b1e2fSJan Kiszka 1455dab5872SJan Kiszka exar_gpio = devm_kzalloc(&pdev->dev, sizeof(*exar_gpio), GFP_KERNEL); 1466596e59eSSudip Mukherjee if (!exar_gpio) 1476596e59eSSudip Mukherjee return -ENOMEM; 1486596e59eSSudip Mukherjee 1496596e59eSSudip Mukherjee mutex_init(&exar_gpio->lock); 1506596e59eSSudip Mukherjee 1516596e59eSSudip Mukherjee index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL); 152333830aaSTakashi Iwai if (index < 0) { 153333830aaSTakashi Iwai ret = index; 154333830aaSTakashi Iwai goto err_mutex_destroy; 155333830aaSTakashi Iwai } 1566596e59eSSudip Mukherjee 1576596e59eSSudip Mukherjee sprintf(exar_gpio->name, "exar_gpio%d", index); 1586596e59eSSudip Mukherjee exar_gpio->gpio_chip.label = exar_gpio->name; 1594076cf08SJan Kiszka exar_gpio->gpio_chip.parent = &pdev->dev; 1606596e59eSSudip Mukherjee exar_gpio->gpio_chip.direction_output = exar_direction_output; 1616596e59eSSudip Mukherjee exar_gpio->gpio_chip.direction_input = exar_direction_input; 1626596e59eSSudip Mukherjee exar_gpio->gpio_chip.get_direction = exar_get_direction; 1636596e59eSSudip Mukherjee exar_gpio->gpio_chip.get = exar_get_value; 1646596e59eSSudip Mukherjee exar_gpio->gpio_chip.set = exar_set_value; 1656596e59eSSudip Mukherjee exar_gpio->gpio_chip.base = -1; 166380b1e2fSJan Kiszka exar_gpio->gpio_chip.ngpio = ngpios; 1676596e59eSSudip Mukherjee exar_gpio->regs = p; 1686596e59eSSudip Mukherjee exar_gpio->index = index; 169380b1e2fSJan Kiszka exar_gpio->first_pin = first_pin; 1706596e59eSSudip Mukherjee 1715dab5872SJan Kiszka ret = devm_gpiochip_add_data(&pdev->dev, 1726596e59eSSudip Mukherjee &exar_gpio->gpio_chip, exar_gpio); 1736596e59eSSudip Mukherjee if (ret) 1746596e59eSSudip Mukherjee goto err_destroy; 1756596e59eSSudip Mukherjee 1766596e59eSSudip Mukherjee platform_set_drvdata(pdev, exar_gpio); 1776596e59eSSudip Mukherjee 1786596e59eSSudip Mukherjee return 0; 1796596e59eSSudip Mukherjee 1806596e59eSSudip Mukherjee err_destroy: 1816596e59eSSudip Mukherjee ida_simple_remove(&ida_index, index); 182333830aaSTakashi Iwai err_mutex_destroy: 1836596e59eSSudip Mukherjee mutex_destroy(&exar_gpio->lock); 1846596e59eSSudip Mukherjee return ret; 1856596e59eSSudip Mukherjee } 1866596e59eSSudip Mukherjee 1876596e59eSSudip Mukherjee static int gpio_exar_remove(struct platform_device *pdev) 1886596e59eSSudip Mukherjee { 1896596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio = platform_get_drvdata(pdev); 1906596e59eSSudip Mukherjee 1916596e59eSSudip Mukherjee ida_simple_remove(&ida_index, exar_gpio->index); 1926596e59eSSudip Mukherjee mutex_destroy(&exar_gpio->lock); 1936596e59eSSudip Mukherjee 1946596e59eSSudip Mukherjee return 0; 1956596e59eSSudip Mukherjee } 1966596e59eSSudip Mukherjee 1976596e59eSSudip Mukherjee static struct platform_driver gpio_exar_driver = { 1986596e59eSSudip Mukherjee .probe = gpio_exar_probe, 1996596e59eSSudip Mukherjee .remove = gpio_exar_remove, 2006596e59eSSudip Mukherjee .driver = { 2016596e59eSSudip Mukherjee .name = DRIVER_NAME, 2026596e59eSSudip Mukherjee }, 2036596e59eSSudip Mukherjee }; 2046596e59eSSudip Mukherjee 2056596e59eSSudip Mukherjee module_platform_driver(gpio_exar_driver); 2066596e59eSSudip Mukherjee 2076596e59eSSudip Mukherjee MODULE_ALIAS("platform:" DRIVER_NAME); 2086596e59eSSudip Mukherjee MODULE_DESCRIPTION("Exar GPIO driver"); 2096596e59eSSudip Mukherjee MODULE_AUTHOR("Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>"); 2106596e59eSSudip Mukherjee MODULE_LICENSE("GPL"); 211