10cc59b9dSMilo Kim /* 20cc59b9dSMilo Kim * TI/National Semiconductor LP3943 GPIO driver 30cc59b9dSMilo Kim * 40cc59b9dSMilo Kim * Copyright 2013 Texas Instruments 50cc59b9dSMilo Kim * 60cc59b9dSMilo Kim * Author: Milo Kim <milo.kim@ti.com> 70cc59b9dSMilo Kim * 80cc59b9dSMilo Kim * This program is free software; you can redistribute it and/or modify 90cc59b9dSMilo Kim * it under the terms of the GNU General Public License as published by 100cc59b9dSMilo Kim * the Free Software Foundation; version 2. 110cc59b9dSMilo Kim */ 120cc59b9dSMilo Kim 130cc59b9dSMilo Kim #include <linux/bitops.h> 140cc59b9dSMilo Kim #include <linux/err.h> 150cc59b9dSMilo Kim #include <linux/gpio.h> 160cc59b9dSMilo Kim #include <linux/i2c.h> 170cc59b9dSMilo Kim #include <linux/mfd/lp3943.h> 180cc59b9dSMilo Kim #include <linux/module.h> 190cc59b9dSMilo Kim #include <linux/platform_device.h> 200cc59b9dSMilo Kim #include <linux/slab.h> 210cc59b9dSMilo Kim 220cc59b9dSMilo Kim enum lp3943_gpios { 230cc59b9dSMilo Kim LP3943_GPIO1, 240cc59b9dSMilo Kim LP3943_GPIO2, 250cc59b9dSMilo Kim LP3943_GPIO3, 260cc59b9dSMilo Kim LP3943_GPIO4, 270cc59b9dSMilo Kim LP3943_GPIO5, 280cc59b9dSMilo Kim LP3943_GPIO6, 290cc59b9dSMilo Kim LP3943_GPIO7, 300cc59b9dSMilo Kim LP3943_GPIO8, 310cc59b9dSMilo Kim LP3943_GPIO9, 320cc59b9dSMilo Kim LP3943_GPIO10, 330cc59b9dSMilo Kim LP3943_GPIO11, 340cc59b9dSMilo Kim LP3943_GPIO12, 350cc59b9dSMilo Kim LP3943_GPIO13, 360cc59b9dSMilo Kim LP3943_GPIO14, 370cc59b9dSMilo Kim LP3943_GPIO15, 380cc59b9dSMilo Kim LP3943_GPIO16, 390cc59b9dSMilo Kim LP3943_MAX_GPIO, 400cc59b9dSMilo Kim }; 410cc59b9dSMilo Kim 420cc59b9dSMilo Kim struct lp3943_gpio { 430cc59b9dSMilo Kim struct gpio_chip chip; 440cc59b9dSMilo Kim struct lp3943 *lp3943; 450cc59b9dSMilo Kim u16 input_mask; /* 1 = GPIO is input direction, 0 = output */ 460cc59b9dSMilo Kim }; 470cc59b9dSMilo Kim 480cc59b9dSMilo Kim static int lp3943_gpio_request(struct gpio_chip *chip, unsigned offset) 490cc59b9dSMilo Kim { 50a2f33804SLinus Walleij struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip); 510cc59b9dSMilo Kim struct lp3943 *lp3943 = lp3943_gpio->lp3943; 520cc59b9dSMilo Kim 530cc59b9dSMilo Kim /* Return an error if the pin is already assigned */ 540cc59b9dSMilo Kim if (test_and_set_bit(offset, &lp3943->pin_used)) 550cc59b9dSMilo Kim return -EBUSY; 560cc59b9dSMilo Kim 570cc59b9dSMilo Kim return 0; 580cc59b9dSMilo Kim } 590cc59b9dSMilo Kim 600cc59b9dSMilo Kim static void lp3943_gpio_free(struct gpio_chip *chip, unsigned offset) 610cc59b9dSMilo Kim { 62a2f33804SLinus Walleij struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip); 630cc59b9dSMilo Kim struct lp3943 *lp3943 = lp3943_gpio->lp3943; 640cc59b9dSMilo Kim 650cc59b9dSMilo Kim clear_bit(offset, &lp3943->pin_used); 660cc59b9dSMilo Kim } 670cc59b9dSMilo Kim 680cc59b9dSMilo Kim static int lp3943_gpio_set_mode(struct lp3943_gpio *lp3943_gpio, u8 offset, 690cc59b9dSMilo Kim u8 val) 700cc59b9dSMilo Kim { 710cc59b9dSMilo Kim struct lp3943 *lp3943 = lp3943_gpio->lp3943; 720cc59b9dSMilo Kim const struct lp3943_reg_cfg *mux = lp3943->mux_cfg; 730cc59b9dSMilo Kim 740cc59b9dSMilo Kim return lp3943_update_bits(lp3943, mux[offset].reg, mux[offset].mask, 750cc59b9dSMilo Kim val << mux[offset].shift); 760cc59b9dSMilo Kim } 770cc59b9dSMilo Kim 780cc59b9dSMilo Kim static int lp3943_gpio_direction_input(struct gpio_chip *chip, unsigned offset) 790cc59b9dSMilo Kim { 80a2f33804SLinus Walleij struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip); 810cc59b9dSMilo Kim 820cc59b9dSMilo Kim lp3943_gpio->input_mask |= BIT(offset); 830cc59b9dSMilo Kim 840cc59b9dSMilo Kim return lp3943_gpio_set_mode(lp3943_gpio, offset, LP3943_GPIO_IN); 850cc59b9dSMilo Kim } 860cc59b9dSMilo Kim 870cc59b9dSMilo Kim static int lp3943_get_gpio_in_status(struct lp3943_gpio *lp3943_gpio, 880cc59b9dSMilo Kim struct gpio_chip *chip, unsigned offset) 890cc59b9dSMilo Kim { 900cc59b9dSMilo Kim u8 addr, read; 910cc59b9dSMilo Kim int err; 920cc59b9dSMilo Kim 930cc59b9dSMilo Kim switch (offset) { 940cc59b9dSMilo Kim case LP3943_GPIO1 ... LP3943_GPIO8: 950cc59b9dSMilo Kim addr = LP3943_REG_GPIO_A; 960cc59b9dSMilo Kim break; 970cc59b9dSMilo Kim case LP3943_GPIO9 ... LP3943_GPIO16: 980cc59b9dSMilo Kim addr = LP3943_REG_GPIO_B; 990cc59b9dSMilo Kim offset = offset - 8; 1000cc59b9dSMilo Kim break; 1010cc59b9dSMilo Kim default: 1020cc59b9dSMilo Kim return -EINVAL; 1030cc59b9dSMilo Kim } 1040cc59b9dSMilo Kim 1050cc59b9dSMilo Kim err = lp3943_read_byte(lp3943_gpio->lp3943, addr, &read); 1060cc59b9dSMilo Kim if (err) 1070cc59b9dSMilo Kim return err; 1080cc59b9dSMilo Kim 1090cc59b9dSMilo Kim return !!(read & BIT(offset)); 1100cc59b9dSMilo Kim } 1110cc59b9dSMilo Kim 1120cc59b9dSMilo Kim static int lp3943_get_gpio_out_status(struct lp3943_gpio *lp3943_gpio, 1130cc59b9dSMilo Kim struct gpio_chip *chip, unsigned offset) 1140cc59b9dSMilo Kim { 1150cc59b9dSMilo Kim struct lp3943 *lp3943 = lp3943_gpio->lp3943; 1160cc59b9dSMilo Kim const struct lp3943_reg_cfg *mux = lp3943->mux_cfg; 1170cc59b9dSMilo Kim u8 read; 1180cc59b9dSMilo Kim int err; 1190cc59b9dSMilo Kim 1200cc59b9dSMilo Kim err = lp3943_read_byte(lp3943, mux[offset].reg, &read); 1210cc59b9dSMilo Kim if (err) 1220cc59b9dSMilo Kim return err; 1230cc59b9dSMilo Kim 1240cc59b9dSMilo Kim read = (read & mux[offset].mask) >> mux[offset].shift; 1250cc59b9dSMilo Kim 1260cc59b9dSMilo Kim if (read == LP3943_GPIO_OUT_HIGH) 1270cc59b9dSMilo Kim return 1; 1280cc59b9dSMilo Kim else if (read == LP3943_GPIO_OUT_LOW) 1290cc59b9dSMilo Kim return 0; 1300cc59b9dSMilo Kim else 1310cc59b9dSMilo Kim return -EINVAL; 1320cc59b9dSMilo Kim } 1330cc59b9dSMilo Kim 1340cc59b9dSMilo Kim static int lp3943_gpio_get(struct gpio_chip *chip, unsigned offset) 1350cc59b9dSMilo Kim { 136a2f33804SLinus Walleij struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip); 1370cc59b9dSMilo Kim 1380cc59b9dSMilo Kim /* 1390cc59b9dSMilo Kim * Limitation: 1400cc59b9dSMilo Kim * LP3943 doesn't have the GPIO direction register. It provides 1410cc59b9dSMilo Kim * only input and output status registers. 1420cc59b9dSMilo Kim * So, direction info is required to handle the 'get' operation. 1430cc59b9dSMilo Kim * This variable is updated whenever the direction is changed and 1440cc59b9dSMilo Kim * it is used here. 1450cc59b9dSMilo Kim */ 1460cc59b9dSMilo Kim 1470cc59b9dSMilo Kim if (lp3943_gpio->input_mask & BIT(offset)) 1480cc59b9dSMilo Kim return lp3943_get_gpio_in_status(lp3943_gpio, chip, offset); 1490cc59b9dSMilo Kim else 1500cc59b9dSMilo Kim return lp3943_get_gpio_out_status(lp3943_gpio, chip, offset); 1510cc59b9dSMilo Kim } 1520cc59b9dSMilo Kim 1530cc59b9dSMilo Kim static void lp3943_gpio_set(struct gpio_chip *chip, unsigned offset, int value) 1540cc59b9dSMilo Kim { 155a2f33804SLinus Walleij struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip); 1560cc59b9dSMilo Kim u8 data; 1570cc59b9dSMilo Kim 1580cc59b9dSMilo Kim if (value) 1590cc59b9dSMilo Kim data = LP3943_GPIO_OUT_HIGH; 1600cc59b9dSMilo Kim else 1610cc59b9dSMilo Kim data = LP3943_GPIO_OUT_LOW; 1620cc59b9dSMilo Kim 1630cc59b9dSMilo Kim lp3943_gpio_set_mode(lp3943_gpio, offset, data); 1640cc59b9dSMilo Kim } 1650cc59b9dSMilo Kim 1660cc59b9dSMilo Kim static int lp3943_gpio_direction_output(struct gpio_chip *chip, unsigned offset, 1670cc59b9dSMilo Kim int value) 1680cc59b9dSMilo Kim { 169a2f33804SLinus Walleij struct lp3943_gpio *lp3943_gpio = gpiochip_get_data(chip); 1700cc59b9dSMilo Kim 1710cc59b9dSMilo Kim lp3943_gpio_set(chip, offset, value); 1720cc59b9dSMilo Kim lp3943_gpio->input_mask &= ~BIT(offset); 1730cc59b9dSMilo Kim 1740cc59b9dSMilo Kim return 0; 1750cc59b9dSMilo Kim } 1760cc59b9dSMilo Kim 1770cc59b9dSMilo Kim static const struct gpio_chip lp3943_gpio_chip = { 1780cc59b9dSMilo Kim .label = "lp3943", 1790cc59b9dSMilo Kim .owner = THIS_MODULE, 1800cc59b9dSMilo Kim .request = lp3943_gpio_request, 1810cc59b9dSMilo Kim .free = lp3943_gpio_free, 1820cc59b9dSMilo Kim .direction_input = lp3943_gpio_direction_input, 1830cc59b9dSMilo Kim .get = lp3943_gpio_get, 1840cc59b9dSMilo Kim .direction_output = lp3943_gpio_direction_output, 1850cc59b9dSMilo Kim .set = lp3943_gpio_set, 1860cc59b9dSMilo Kim .base = -1, 1870cc59b9dSMilo Kim .ngpio = LP3943_MAX_GPIO, 1880cc59b9dSMilo Kim .can_sleep = 1, 1890cc59b9dSMilo Kim }; 1900cc59b9dSMilo Kim 1910cc59b9dSMilo Kim static int lp3943_gpio_probe(struct platform_device *pdev) 1920cc59b9dSMilo Kim { 1930cc59b9dSMilo Kim struct lp3943 *lp3943 = dev_get_drvdata(pdev->dev.parent); 1940cc59b9dSMilo Kim struct lp3943_gpio *lp3943_gpio; 1950cc59b9dSMilo Kim 1960cc59b9dSMilo Kim lp3943_gpio = devm_kzalloc(&pdev->dev, sizeof(*lp3943_gpio), 1970cc59b9dSMilo Kim GFP_KERNEL); 1980cc59b9dSMilo Kim if (!lp3943_gpio) 1990cc59b9dSMilo Kim return -ENOMEM; 2000cc59b9dSMilo Kim 2010cc59b9dSMilo Kim lp3943_gpio->lp3943 = lp3943; 2020cc59b9dSMilo Kim lp3943_gpio->chip = lp3943_gpio_chip; 20358383c78SLinus Walleij lp3943_gpio->chip.parent = &pdev->dev; 2040cc59b9dSMilo Kim 2050cc59b9dSMilo Kim platform_set_drvdata(pdev, lp3943_gpio); 2060cc59b9dSMilo Kim 207a2f33804SLinus Walleij return gpiochip_add_data(&lp3943_gpio->chip, lp3943_gpio); 2080cc59b9dSMilo Kim } 2090cc59b9dSMilo Kim 2100cc59b9dSMilo Kim static int lp3943_gpio_remove(struct platform_device *pdev) 2110cc59b9dSMilo Kim { 2120cc59b9dSMilo Kim struct lp3943_gpio *lp3943_gpio = platform_get_drvdata(pdev); 2130cc59b9dSMilo Kim 2149f5132aeSabdoulaye berthe gpiochip_remove(&lp3943_gpio->chip); 2159f5132aeSabdoulaye berthe return 0; 2160cc59b9dSMilo Kim } 2170cc59b9dSMilo Kim 2180cc59b9dSMilo Kim static const struct of_device_id lp3943_gpio_of_match[] = { 2190cc59b9dSMilo Kim { .compatible = "ti,lp3943-gpio", }, 2200cc59b9dSMilo Kim { } 2210cc59b9dSMilo Kim }; 2220cc59b9dSMilo Kim MODULE_DEVICE_TABLE(of, lp3943_gpio_of_match); 2230cc59b9dSMilo Kim 2240cc59b9dSMilo Kim static struct platform_driver lp3943_gpio_driver = { 2250cc59b9dSMilo Kim .probe = lp3943_gpio_probe, 2260cc59b9dSMilo Kim .remove = lp3943_gpio_remove, 2270cc59b9dSMilo Kim .driver = { 2280cc59b9dSMilo Kim .name = "lp3943-gpio", 2293b1ba0cbSSachin Kamat .of_match_table = lp3943_gpio_of_match, 2300cc59b9dSMilo Kim }, 2310cc59b9dSMilo Kim }; 2320cc59b9dSMilo Kim module_platform_driver(lp3943_gpio_driver); 2330cc59b9dSMilo Kim 2340cc59b9dSMilo Kim MODULE_DESCRIPTION("LP3943 GPIO driver"); 2350cc59b9dSMilo Kim MODULE_ALIAS("platform:lp3943-gpio"); 2360cc59b9dSMilo Kim MODULE_AUTHOR("Milo Kim"); 2370cc59b9dSMilo Kim MODULE_LICENSE("GPL"); 238