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 */ 71bfaf129SBartosz Golaszewski 86596e59eSSudip Mukherjee #include <linux/bitops.h> 96596e59eSSudip Mukherjee #include <linux/device.h> 106596e59eSSudip Mukherjee #include <linux/gpio/driver.h> 1126ced453SBartosz Golaszewski #include <linux/idr.h> 126596e59eSSudip Mukherjee #include <linux/init.h> 136596e59eSSudip Mukherjee #include <linux/kernel.h> 146596e59eSSudip Mukherjee #include <linux/module.h> 156596e59eSSudip Mukherjee #include <linux/pci.h> 166596e59eSSudip Mukherjee #include <linux/platform_device.h> 176596e59eSSudip Mukherjee 186596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOLVL_LO 0x90 196596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOSEL_LO 0x93 206596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOLVL_HI 0x96 216596e59eSSudip Mukherjee #define EXAR_OFFSET_MPIOSEL_HI 0x99 226596e59eSSudip Mukherjee 236596e59eSSudip Mukherjee #define DRIVER_NAME "gpio_exar" 246596e59eSSudip Mukherjee 256596e59eSSudip Mukherjee static DEFINE_IDA(ida_index); 266596e59eSSudip Mukherjee 276596e59eSSudip Mukherjee struct exar_gpio_chip { 286596e59eSSudip Mukherjee struct gpio_chip gpio_chip; 296596e59eSSudip Mukherjee struct mutex lock; 306596e59eSSudip Mukherjee int index; 316596e59eSSudip Mukherjee void __iomem *regs; 326596e59eSSudip Mukherjee char name[20]; 33380b1e2fSJan Kiszka unsigned int first_pin; 346596e59eSSudip Mukherjee }; 356596e59eSSudip Mukherjee 36*696868d0SBartosz Golaszewski static unsigned int 37*696868d0SBartosz Golaszewski exar_offset_to_sel_addr(struct exar_gpio_chip *exar_gpio, unsigned int offset) 38*696868d0SBartosz Golaszewski { 39*696868d0SBartosz Golaszewski return (offset + exar_gpio->first_pin) / 8 ? EXAR_OFFSET_MPIOSEL_HI 40*696868d0SBartosz Golaszewski : EXAR_OFFSET_MPIOSEL_LO; 41*696868d0SBartosz Golaszewski } 42*696868d0SBartosz Golaszewski 43*696868d0SBartosz Golaszewski static unsigned int 44*696868d0SBartosz Golaszewski exar_offset_to_lvl_addr(struct exar_gpio_chip *exar_gpio, unsigned int offset) 45*696868d0SBartosz Golaszewski { 46*696868d0SBartosz Golaszewski return (offset + exar_gpio->first_pin) / 8 ? EXAR_OFFSET_MPIOLVL_HI 47*696868d0SBartosz Golaszewski : EXAR_OFFSET_MPIOLVL_LO; 48*696868d0SBartosz Golaszewski } 49*696868d0SBartosz Golaszewski 50*696868d0SBartosz Golaszewski static unsigned int 51*696868d0SBartosz Golaszewski exar_offset_to_bit(struct exar_gpio_chip *exar_gpio, unsigned int offset) 52*696868d0SBartosz Golaszewski { 53*696868d0SBartosz Golaszewski return (offset + exar_gpio->first_pin) % 8; 54*696868d0SBartosz Golaszewski } 55*696868d0SBartosz Golaszewski 566596e59eSSudip Mukherjee static void exar_update(struct gpio_chip *chip, unsigned int reg, int val, 576596e59eSSudip Mukherjee unsigned int offset) 586596e59eSSudip Mukherjee { 596596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 606596e59eSSudip Mukherjee int temp; 616596e59eSSudip Mukherjee 626596e59eSSudip Mukherjee mutex_lock(&exar_gpio->lock); 636596e59eSSudip Mukherjee temp = readb(exar_gpio->regs + reg); 646596e59eSSudip Mukherjee temp &= ~BIT(offset); 656596e59eSSudip Mukherjee if (val) 666596e59eSSudip Mukherjee temp |= BIT(offset); 676596e59eSSudip Mukherjee writeb(temp, exar_gpio->regs + reg); 686596e59eSSudip Mukherjee mutex_unlock(&exar_gpio->lock); 696596e59eSSudip Mukherjee } 706596e59eSSudip Mukherjee 716596e59eSSudip Mukherjee static int exar_set_direction(struct gpio_chip *chip, int direction, 726596e59eSSudip Mukherjee unsigned int offset) 736596e59eSSudip Mukherjee { 74380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 75*696868d0SBartosz Golaszewski unsigned int addr = exar_offset_to_sel_addr(exar_gpio, offset); 76*696868d0SBartosz Golaszewski unsigned int bit = exar_offset_to_bit(exar_gpio, offset); 776596e59eSSudip Mukherjee 78380b1e2fSJan Kiszka exar_update(chip, addr, direction, bit); 796596e59eSSudip Mukherjee return 0; 806596e59eSSudip Mukherjee } 816596e59eSSudip Mukherjee 826596e59eSSudip Mukherjee static int exar_get(struct gpio_chip *chip, unsigned int reg) 836596e59eSSudip Mukherjee { 846596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 856596e59eSSudip Mukherjee int value; 866596e59eSSudip Mukherjee 876596e59eSSudip Mukherjee mutex_lock(&exar_gpio->lock); 886596e59eSSudip Mukherjee value = readb(exar_gpio->regs + reg); 896596e59eSSudip Mukherjee mutex_unlock(&exar_gpio->lock); 906596e59eSSudip Mukherjee 917f45a875SJan Kiszka return value; 926596e59eSSudip Mukherjee } 936596e59eSSudip Mukherjee 946596e59eSSudip Mukherjee static int exar_get_direction(struct gpio_chip *chip, unsigned int offset) 956596e59eSSudip Mukherjee { 96380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 97*696868d0SBartosz Golaszewski unsigned int addr = exar_offset_to_sel_addr(exar_gpio, offset); 98*696868d0SBartosz Golaszewski unsigned int bit = exar_offset_to_bit(exar_gpio, offset); 996596e59eSSudip Mukherjee 100e42615ecSMatti Vaittinen if (exar_get(chip, addr) & BIT(bit)) 101e42615ecSMatti Vaittinen return GPIO_LINE_DIRECTION_IN; 102e42615ecSMatti Vaittinen 103e42615ecSMatti Vaittinen return GPIO_LINE_DIRECTION_OUT; 1046596e59eSSudip Mukherjee } 1056596e59eSSudip Mukherjee 1066596e59eSSudip Mukherjee static int exar_get_value(struct gpio_chip *chip, unsigned int offset) 1076596e59eSSudip Mukherjee { 108380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 109*696868d0SBartosz Golaszewski unsigned int addr = exar_offset_to_lvl_addr(exar_gpio, offset); 110*696868d0SBartosz Golaszewski unsigned int bit = exar_offset_to_bit(exar_gpio, offset); 1116596e59eSSudip Mukherjee 112380b1e2fSJan Kiszka return !!(exar_get(chip, addr) & BIT(bit)); 1136596e59eSSudip Mukherjee } 1146596e59eSSudip Mukherjee 1156596e59eSSudip Mukherjee static void exar_set_value(struct gpio_chip *chip, unsigned int offset, 1166596e59eSSudip Mukherjee int value) 1176596e59eSSudip Mukherjee { 118380b1e2fSJan Kiszka struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 119*696868d0SBartosz Golaszewski unsigned int addr = exar_offset_to_lvl_addr(exar_gpio, offset); 120*696868d0SBartosz Golaszewski unsigned int bit = exar_offset_to_bit(exar_gpio, offset); 1216596e59eSSudip Mukherjee 122380b1e2fSJan Kiszka exar_update(chip, addr, value, bit); 1236596e59eSSudip Mukherjee } 1246596e59eSSudip Mukherjee 125eddeae07SAxel Lin static int exar_direction_output(struct gpio_chip *chip, unsigned int offset, 126eddeae07SAxel Lin int value) 127eddeae07SAxel Lin { 128eddeae07SAxel Lin exar_set_value(chip, offset, value); 129eddeae07SAxel Lin return exar_set_direction(chip, 0, offset); 130eddeae07SAxel Lin } 131eddeae07SAxel Lin 132eddeae07SAxel Lin static int exar_direction_input(struct gpio_chip *chip, unsigned int offset) 133eddeae07SAxel Lin { 134eddeae07SAxel Lin return exar_set_direction(chip, 1, offset); 135eddeae07SAxel Lin } 136eddeae07SAxel Lin 1376596e59eSSudip Mukherjee static int gpio_exar_probe(struct platform_device *pdev) 1386596e59eSSudip Mukherjee { 1390c2c7e13SBartosz Golaszewski struct device *dev = &pdev->dev; 1400c2c7e13SBartosz Golaszewski struct pci_dev *pcidev = to_pci_dev(dev->parent); 1416596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio; 142380b1e2fSJan Kiszka u32 first_pin, ngpios; 1436596e59eSSudip Mukherjee void __iomem *p; 1446596e59eSSudip Mukherjee int index, ret; 1456596e59eSSudip Mukherjee 1466596e59eSSudip Mukherjee /* 1478847f5f9SJan Kiszka * The UART driver must have mapped region 0 prior to registering this 1488847f5f9SJan Kiszka * device - use it. 1496596e59eSSudip Mukherjee */ 1508847f5f9SJan Kiszka p = pcim_iomap_table(pcidev)[0]; 1516596e59eSSudip Mukherjee if (!p) 1526596e59eSSudip Mukherjee return -ENOMEM; 1536596e59eSSudip Mukherjee 1540c2c7e13SBartosz Golaszewski ret = device_property_read_u32(dev, "exar,first-pin", &first_pin); 155380b1e2fSJan Kiszka if (ret) 156380b1e2fSJan Kiszka return ret; 157380b1e2fSJan Kiszka 1580c2c7e13SBartosz Golaszewski ret = device_property_read_u32(dev, "ngpios", &ngpios); 159380b1e2fSJan Kiszka if (ret) 160380b1e2fSJan Kiszka return ret; 161380b1e2fSJan Kiszka 1620c2c7e13SBartosz Golaszewski exar_gpio = devm_kzalloc(dev, sizeof(*exar_gpio), GFP_KERNEL); 1636596e59eSSudip Mukherjee if (!exar_gpio) 1646596e59eSSudip Mukherjee return -ENOMEM; 1656596e59eSSudip Mukherjee 1666596e59eSSudip Mukherjee mutex_init(&exar_gpio->lock); 1676596e59eSSudip Mukherjee 1688e27c2aeSBartosz Golaszewski index = ida_alloc(&ida_index, GFP_KERNEL); 169333830aaSTakashi Iwai if (index < 0) { 170333830aaSTakashi Iwai ret = index; 171333830aaSTakashi Iwai goto err_mutex_destroy; 172333830aaSTakashi Iwai } 1736596e59eSSudip Mukherjee 1746596e59eSSudip Mukherjee sprintf(exar_gpio->name, "exar_gpio%d", index); 1756596e59eSSudip Mukherjee exar_gpio->gpio_chip.label = exar_gpio->name; 1760c2c7e13SBartosz Golaszewski exar_gpio->gpio_chip.parent = dev; 1776596e59eSSudip Mukherjee exar_gpio->gpio_chip.direction_output = exar_direction_output; 1786596e59eSSudip Mukherjee exar_gpio->gpio_chip.direction_input = exar_direction_input; 1796596e59eSSudip Mukherjee exar_gpio->gpio_chip.get_direction = exar_get_direction; 1806596e59eSSudip Mukherjee exar_gpio->gpio_chip.get = exar_get_value; 1816596e59eSSudip Mukherjee exar_gpio->gpio_chip.set = exar_set_value; 1826596e59eSSudip Mukherjee exar_gpio->gpio_chip.base = -1; 183380b1e2fSJan Kiszka exar_gpio->gpio_chip.ngpio = ngpios; 1846596e59eSSudip Mukherjee exar_gpio->regs = p; 1856596e59eSSudip Mukherjee exar_gpio->index = index; 186380b1e2fSJan Kiszka exar_gpio->first_pin = first_pin; 1876596e59eSSudip Mukherjee 1880c2c7e13SBartosz Golaszewski ret = devm_gpiochip_add_data(dev, &exar_gpio->gpio_chip, exar_gpio); 1896596e59eSSudip Mukherjee if (ret) 1906596e59eSSudip Mukherjee goto err_destroy; 1916596e59eSSudip Mukherjee 1926596e59eSSudip Mukherjee platform_set_drvdata(pdev, exar_gpio); 1936596e59eSSudip Mukherjee 1946596e59eSSudip Mukherjee return 0; 1956596e59eSSudip Mukherjee 1966596e59eSSudip Mukherjee err_destroy: 1978e27c2aeSBartosz Golaszewski ida_free(&ida_index, index); 198333830aaSTakashi Iwai err_mutex_destroy: 1996596e59eSSudip Mukherjee mutex_destroy(&exar_gpio->lock); 2006596e59eSSudip Mukherjee return ret; 2016596e59eSSudip Mukherjee } 2026596e59eSSudip Mukherjee 2036596e59eSSudip Mukherjee static int gpio_exar_remove(struct platform_device *pdev) 2046596e59eSSudip Mukherjee { 2056596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio = platform_get_drvdata(pdev); 2066596e59eSSudip Mukherjee 2078e27c2aeSBartosz Golaszewski ida_free(&ida_index, exar_gpio->index); 2086596e59eSSudip Mukherjee mutex_destroy(&exar_gpio->lock); 2096596e59eSSudip Mukherjee 2106596e59eSSudip Mukherjee return 0; 2116596e59eSSudip Mukherjee } 2126596e59eSSudip Mukherjee 2136596e59eSSudip Mukherjee static struct platform_driver gpio_exar_driver = { 2146596e59eSSudip Mukherjee .probe = gpio_exar_probe, 2156596e59eSSudip Mukherjee .remove = gpio_exar_remove, 2166596e59eSSudip Mukherjee .driver = { 2176596e59eSSudip Mukherjee .name = DRIVER_NAME, 2186596e59eSSudip Mukherjee }, 2196596e59eSSudip Mukherjee }; 2206596e59eSSudip Mukherjee 2216596e59eSSudip Mukherjee module_platform_driver(gpio_exar_driver); 2226596e59eSSudip Mukherjee 2236596e59eSSudip Mukherjee MODULE_ALIAS("platform:" DRIVER_NAME); 2246596e59eSSudip Mukherjee MODULE_DESCRIPTION("Exar GPIO driver"); 2256596e59eSSudip Mukherjee MODULE_AUTHOR("Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>"); 2266596e59eSSudip Mukherjee MODULE_LICENSE("GPL"); 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