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Release 4.11 drivers/gpio/gpio-exar.c

Directory: drivers/gpio
/*
 * GPIO driver for Exar XR17V35X chip
 *
 * Copyright (C) 2015 Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/bitops.h>
#include <linux/device.h>
#include <linux/gpio/driver.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/platform_device.h>


#define EXAR_OFFSET_MPIOLVL_LO 0x90

#define EXAR_OFFSET_MPIOSEL_LO 0x93

#define EXAR_OFFSET_MPIOLVL_HI 0x96

#define EXAR_OFFSET_MPIOSEL_HI 0x99


#define DRIVER_NAME "gpio_exar"

static DEFINE_IDA(ida_index);


struct exar_gpio_chip {
	
struct gpio_chip gpio_chip;
	
struct mutex lock;
	
int index;
	
void __iomem *regs;
	
char name[20];
};


static void exar_update(struct gpio_chip *chip, unsigned int reg, int val, unsigned int offset) { struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); int temp; mutex_lock(&exar_gpio->lock); temp = readb(exar_gpio->regs + reg); temp &= ~BIT(offset); if (val) temp |= BIT(offset); writeb(temp, exar_gpio->regs + reg); mutex_unlock(&exar_gpio->lock); }

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Sudip Mukherjee92100.00%1100.00%
Total92100.00%1100.00%


static int exar_set_direction(struct gpio_chip *chip, int direction, unsigned int offset) { unsigned int bank = offset / 8; unsigned int addr; addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO; exar_update(chip, addr, direction, offset % 8); return 0; }

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Sudip Mukherjee54100.00%1100.00%
Total54100.00%1100.00%


static int exar_direction_output(struct gpio_chip *chip, unsigned int offset, int value) { return exar_set_direction(chip, 0, offset); }

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Sudip Mukherjee28100.00%1100.00%
Total28100.00%1100.00%


static int exar_direction_input(struct gpio_chip *chip, unsigned int offset) { return exar_set_direction(chip, 1, offset); }

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Sudip Mukherjee25100.00%1100.00%
Total25100.00%1100.00%


static int exar_get(struct gpio_chip *chip, unsigned int reg) { struct exar_gpio_chip *exar_gpio = gpiochip_get_data(chip); int value; mutex_lock(&exar_gpio->lock); value = readb(exar_gpio->regs + reg); mutex_unlock(&exar_gpio->lock); return !!value; }

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Sudip Mukherjee60100.00%1100.00%
Total60100.00%1100.00%


static int exar_get_direction(struct gpio_chip *chip, unsigned int offset) { unsigned int bank = offset / 8; unsigned int addr; int val; addr = bank ? EXAR_OFFSET_MPIOSEL_HI : EXAR_OFFSET_MPIOSEL_LO; val = exar_get(chip, addr) >> (offset % 8); return !!val; }

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Sudip Mukherjee58100.00%1100.00%
Total58100.00%1100.00%


static int exar_get_value(struct gpio_chip *chip, unsigned int offset) { unsigned int bank = offset / 8; unsigned int addr; int val; addr = bank ? EXAR_OFFSET_MPIOLVL_LO : EXAR_OFFSET_MPIOLVL_HI; val = exar_get(chip, addr) >> (offset % 8); return !!val; }

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Sudip Mukherjee58100.00%1100.00%
Total58100.00%1100.00%


static void exar_set_value(struct gpio_chip *chip, unsigned int offset, int value) { unsigned int bank = offset / 8; unsigned int addr; addr = bank ? EXAR_OFFSET_MPIOLVL_HI : EXAR_OFFSET_MPIOLVL_LO; exar_update(chip, addr, value, offset % 8); }

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Sudip Mukherjee51100.00%1100.00%
Total51100.00%1100.00%


static int gpio_exar_probe(struct platform_device *pdev) { struct pci_dev *pcidev = platform_get_drvdata(pdev); struct exar_gpio_chip *exar_gpio; void __iomem *p; int index, ret; if (pcidev->vendor != PCI_VENDOR_ID_EXAR) return -ENODEV; /* * Map the pci device to get the register addresses. * We will need to read and write those registers to control * the GPIO pins. * Using managed functions will save us from unmaping on exit. * As the device is enabled using managed functions by the * UART driver we can also use managed functions here. */ p = pcim_iomap(pcidev, 0, 0); if (!p) return -ENOMEM; exar_gpio = devm_kzalloc(&pcidev->dev, sizeof(*exar_gpio), GFP_KERNEL); if (!exar_gpio) return -ENOMEM; mutex_init(&exar_gpio->lock); index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL); sprintf(exar_gpio->name, "exar_gpio%d", index); exar_gpio->gpio_chip.label = exar_gpio->name; exar_gpio->gpio_chip.parent = &pcidev->dev; exar_gpio->gpio_chip.direction_output = exar_direction_output; exar_gpio->gpio_chip.direction_input = exar_direction_input; exar_gpio->gpio_chip.get_direction = exar_get_direction; exar_gpio->gpio_chip.get = exar_get_value; exar_gpio->gpio_chip.set = exar_set_value; exar_gpio->gpio_chip.base = -1; exar_gpio->gpio_chip.ngpio = 16; exar_gpio->regs = p; exar_gpio->index = index; ret = devm_gpiochip_add_data(&pcidev->dev, &exar_gpio->gpio_chip, exar_gpio); if (ret) goto err_destroy; platform_set_drvdata(pdev, exar_gpio); return 0; err_destroy: ida_simple_remove(&ida_index, index); mutex_destroy(&exar_gpio->lock); return ret; }

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Sudip Mukherjee274100.00%1100.00%
Total274100.00%1100.00%


static int gpio_exar_remove(struct platform_device *pdev) { struct exar_gpio_chip *exar_gpio = platform_get_drvdata(pdev); ida_simple_remove(&ida_index, exar_gpio->index); mutex_destroy(&exar_gpio->lock); return 0; }

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Sudip Mukherjee42100.00%1100.00%
Total42100.00%1100.00%

static struct platform_driver gpio_exar_driver = { .probe = gpio_exar_probe, .remove = gpio_exar_remove, .driver = { .name = DRIVER_NAME, }, }; module_platform_driver(gpio_exar_driver); MODULE_ALIAS("platform:" DRIVER_NAME); MODULE_DESCRIPTION("Exar GPIO driver"); MODULE_AUTHOR("Sudip Mukherjee <sudip.mukherjee@codethink.co.uk>"); MODULE_LICENSE("GPL");

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Directory: drivers/gpio
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