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]; 346596e59eSSudip Mukherjee }; 356596e59eSSudip Mukherjee 366596e59eSSudip Mukherjee static void exar_update(struct gpio_chip *chip, unsigned int reg, int val, 376596e59eSSudip Mukherjee unsigned int offset) 386596e59eSSudip Mukherjee { 396596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); 406596e59eSSudip Mukherjee int temp; 416596e59eSSudip Mukherjee 426596e59eSSudip Mukherjee mutex_lock(&exar_gpio->lock); 436596e59eSSudip Mukherjee temp = readb(exar_gpio->regs + reg); 446596e59eSSudip Mukherjee temp &= ~BIT(offset); 456596e59eSSudip Mukherjee if (val) 466596e59eSSudip Mukherjee temp |= BIT(offset); 476596e59eSSudip Mukherjee writeb(temp, exar_gpio->regs + reg); 486596e59eSSudip Mukherjee mutex_unlock(&exar_gpio->lock); 496596e59eSSudip Mukherjee } 506596e59eSSudip Mukherjee 516596e59eSSudip Mukherjee static int exar_set_direction(struct gpio_chip *chip, int direction, 526596e59eSSudip Mukherjee unsigned int offset) 536596e59eSSudip Mukherjee { 546596e59eSSudip Mukherjee unsigned int bank = offset / 8; 556596e59eSSudip Mukherjee unsigned int addr; 566596e59eSSudip Mukherjee 576596e59eSSudip Mukherjee addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO; 586596e59eSSudip Mukherjee exar_update(chip, addr, direction, offset % 8); 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 716596e59eSSudip Mukherjee return !!value; 726596e59eSSudip Mukherjee } 736596e59eSSudip Mukherjee 746596e59eSSudip Mukherjee static int exar_get_direction(struct gpio_chip *chip, unsigned int offset) 756596e59eSSudip Mukherjee { 766596e59eSSudip Mukherjee unsigned int bank = offset / 8; 776596e59eSSudip Mukherjee unsigned int addr; 786596e59eSSudip Mukherjee int val; 796596e59eSSudip Mukherjee 806596e59eSSudip Mukherjee addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO; 816596e59eSSudip Mukherjee val = exar_get(chip, addr) >> (offset % 8); 826596e59eSSudip Mukherjee 836596e59eSSudip Mukherjee return !!val; 846596e59eSSudip Mukherjee } 856596e59eSSudip Mukherjee 866596e59eSSudip Mukherjee static int exar_get_value(struct gpio_chip *chip, unsigned int offset) 876596e59eSSudip Mukherjee { 886596e59eSSudip Mukherjee unsigned int bank = offset / 8; 896596e59eSSudip Mukherjee unsigned int addr; 906596e59eSSudip Mukherjee int val; 916596e59eSSudip Mukherjee 926596e59eSSudip Mukherjee addr = bank ? EXAR_OFFSET_MPIOLVL_LO : EXAR_OFFSET_MPIOLVL_HI; 936596e59eSSudip Mukherjee val = exar_get(chip, addr) >> (offset % 8); 946596e59eSSudip Mukherjee 956596e59eSSudip Mukherjee return !!val; 966596e59eSSudip Mukherjee } 976596e59eSSudip Mukherjee 986596e59eSSudip Mukherjee static void exar_set_value(struct gpio_chip *chip, unsigned int offset, 996596e59eSSudip Mukherjee int value) 1006596e59eSSudip Mukherjee { 1016596e59eSSudip Mukherjee unsigned int bank = offset / 8; 1026596e59eSSudip Mukherjee unsigned int addr; 1036596e59eSSudip Mukherjee 1046596e59eSSudip Mukherjee addr = bank ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO; 1056596e59eSSudip Mukherjee exar_update(chip, addr, value, offset % 8); 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; 1246596e59eSSudip Mukherjee void __iomem *p; 1256596e59eSSudip Mukherjee int index, ret; 1266596e59eSSudip Mukherjee 1276596e59eSSudip Mukherjee if (pcidev->vendor != PCI_VENDOR_ID_EXAR) 1286596e59eSSudip Mukherjee return -ENODEV; 1296596e59eSSudip Mukherjee 1306596e59eSSudip Mukherjee /* 1316596e59eSSudip Mukherjee * Map the pci device to get the register addresses. 1326596e59eSSudip Mukherjee * We will need to read and write those registers to control 1336596e59eSSudip Mukherjee * the GPIO pins. 1346596e59eSSudip Mukherjee * Using managed functions will save us from unmaping on exit. 1356596e59eSSudip Mukherjee * As the device is enabled using managed functions by the 1366596e59eSSudip Mukherjee * UART driver we can also use managed functions here. 1376596e59eSSudip Mukherjee */ 1386596e59eSSudip Mukherjee p = pcim_iomap(pcidev, 0, 0); 1396596e59eSSudip Mukherjee if (!p) 1406596e59eSSudip Mukherjee return -ENOMEM; 1416596e59eSSudip Mukherjee 1425dab5872SJan Kiszka exar_gpio = devm_kzalloc(&pdev->dev, sizeof(*exar_gpio), GFP_KERNEL); 1436596e59eSSudip Mukherjee if (!exar_gpio) 1446596e59eSSudip Mukherjee return -ENOMEM; 1456596e59eSSudip Mukherjee 1466596e59eSSudip Mukherjee mutex_init(&exar_gpio->lock); 1476596e59eSSudip Mukherjee 1486596e59eSSudip Mukherjee index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL); 1496596e59eSSudip Mukherjee 1506596e59eSSudip Mukherjee sprintf(exar_gpio->name, "exar_gpio%d", index); 1516596e59eSSudip Mukherjee exar_gpio->gpio_chip.label = exar_gpio->name; 1526596e59eSSudip Mukherjee exar_gpio->gpio_chip.parent = &pcidev->dev; 1536596e59eSSudip Mukherjee exar_gpio->gpio_chip.direction_output = exar_direction_output; 1546596e59eSSudip Mukherjee exar_gpio->gpio_chip.direction_input = exar_direction_input; 1556596e59eSSudip Mukherjee exar_gpio->gpio_chip.get_direction = exar_get_direction; 1566596e59eSSudip Mukherjee exar_gpio->gpio_chip.get = exar_get_value; 1576596e59eSSudip Mukherjee exar_gpio->gpio_chip.set = exar_set_value; 1586596e59eSSudip Mukherjee exar_gpio->gpio_chip.base = -1; 1596596e59eSSudip Mukherjee exar_gpio->gpio_chip.ngpio = 16; 1606596e59eSSudip Mukherjee exar_gpio->regs = p; 1616596e59eSSudip Mukherjee exar_gpio->index = index; 1626596e59eSSudip Mukherjee 1635dab5872SJan Kiszka ret = devm_gpiochip_add_data(&pdev->dev, 1646596e59eSSudip Mukherjee &exar_gpio->gpio_chip, exar_gpio); 1656596e59eSSudip Mukherjee if (ret) 1666596e59eSSudip Mukherjee goto err_destroy; 1676596e59eSSudip Mukherjee 1686596e59eSSudip Mukherjee platform_set_drvdata(pdev, exar_gpio); 1696596e59eSSudip Mukherjee 1706596e59eSSudip Mukherjee return 0; 1716596e59eSSudip Mukherjee 1726596e59eSSudip Mukherjee err_destroy: 1736596e59eSSudip Mukherjee ida_simple_remove(&ida_index, index); 1746596e59eSSudip Mukherjee mutex_destroy(&exar_gpio->lock); 1756596e59eSSudip Mukherjee return ret; 1766596e59eSSudip Mukherjee } 1776596e59eSSudip Mukherjee 1786596e59eSSudip Mukherjee static int gpio_exar_remove(struct platform_device *pdev) 1796596e59eSSudip Mukherjee { 1806596e59eSSudip Mukherjee struct exar_gpio_chip *exar_gpio = platform_get_drvdata(pdev); 1816596e59eSSudip Mukherjee 1826596e59eSSudip Mukherjee ida_simple_remove(&ida_index, exar_gpio->index); 1836596e59eSSudip Mukherjee mutex_destroy(&exar_gpio->lock); 1846596e59eSSudip Mukherjee 1856596e59eSSudip Mukherjee return 0; 1866596e59eSSudip Mukherjee } 1876596e59eSSudip Mukherjee 1886596e59eSSudip Mukherjee static struct platform_driver gpio_exar_driver = { 1896596e59eSSudip Mukherjee .probe = gpio_exar_probe, 1906596e59eSSudip Mukherjee .remove = gpio_exar_remove, 1916596e59eSSudip Mukherjee .driver = { 1926596e59eSSudip Mukherjee .name = DRIVER_NAME, 1936596e59eSSudip Mukherjee }, 1946596e59eSSudip Mukherjee }; 1956596e59eSSudip Mukherjee 1966596e59eSSudip Mukherjee module_platform_driver(gpio_exar_driver); 1976596e59eSSudip Mukherjee 1986596e59eSSudip Mukherjee MODULE_ALIAS("platform:" DRIVER_NAME); 1996596e59eSSudip Mukherjee MODULE_DESCRIPTION("Exar GPIO driver"); 2006596e59eSSudip Mukherjee MODULE_AUTHOR("Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>"); 2016596e59eSSudip Mukherjee MODULE_LICENSE("GPL"); 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