1 /* 2 * Copyright Intel Corporation (C) 2014-2016. All Rights Reserved 3 * 4 * This program is free software; you can redistribute it and/or modify it 5 * under the terms and conditions of the GNU General Public License, 6 * version 2, as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope it will be useful, but WITHOUT 9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 11 * more details. 12 * 13 * You should have received a copy of the GNU General Public License along with 14 * this program. If not, see <http://www.gnu.org/licenses/>. 15 * 16 * GPIO driver for Altera Arria10 MAX5 System Resource Chip 17 * 18 * Adapted from gpio-tps65910.c 19 */ 20 21 #include <linux/gpio/driver.h> 22 #include <linux/mfd/altera-a10sr.h> 23 #include <linux/module.h> 24 25 /** 26 * struct altr_a10sr_gpio - Altera Max5 GPIO device private data structure 27 * @gp: : instance of the gpio_chip 28 * @regmap: the regmap from the parent device. 29 */ 30 struct altr_a10sr_gpio { 31 struct gpio_chip gp; 32 struct regmap *regmap; 33 }; 34 35 static int altr_a10sr_gpio_get(struct gpio_chip *chip, unsigned int offset) 36 { 37 struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip); 38 int ret, val; 39 40 ret = regmap_read(gpio->regmap, ALTR_A10SR_PBDSW_REG, &val); 41 if (ret < 0) 42 return ret; 43 44 return !!(val & BIT(offset - ALTR_A10SR_LED_VALID_SHIFT)); 45 } 46 47 static void altr_a10sr_gpio_set(struct gpio_chip *chip, unsigned int offset, 48 int value) 49 { 50 struct altr_a10sr_gpio *gpio = gpiochip_get_data(chip); 51 52 regmap_update_bits(gpio->regmap, ALTR_A10SR_LED_REG, 53 BIT(ALTR_A10SR_LED_VALID_SHIFT + offset), 54 value ? BIT(ALTR_A10SR_LED_VALID_SHIFT + offset) 55 : 0); 56 } 57 58 static int altr_a10sr_gpio_direction_input(struct gpio_chip *gc, 59 unsigned int nr) 60 { 61 if (nr >= (ALTR_A10SR_IN_VALID_RANGE_LO - ALTR_A10SR_LED_VALID_SHIFT)) 62 return 0; 63 return -EINVAL; 64 } 65 66 static int altr_a10sr_gpio_direction_output(struct gpio_chip *gc, 67 unsigned int nr, int value) 68 { 69 if (nr <= (ALTR_A10SR_OUT_VALID_RANGE_HI - ALTR_A10SR_LED_VALID_SHIFT)) 70 return 0; 71 return -EINVAL; 72 } 73 74 static const struct gpio_chip altr_a10sr_gc = { 75 .label = "altr_a10sr_gpio", 76 .owner = THIS_MODULE, 77 .get = altr_a10sr_gpio_get, 78 .set = altr_a10sr_gpio_set, 79 .direction_input = altr_a10sr_gpio_direction_input, 80 .direction_output = altr_a10sr_gpio_direction_output, 81 .can_sleep = true, 82 .ngpio = 12, 83 .base = -1, 84 }; 85 86 static int altr_a10sr_gpio_probe(struct platform_device *pdev) 87 { 88 struct altr_a10sr_gpio *gpio; 89 int ret; 90 struct altr_a10sr *a10sr = dev_get_drvdata(pdev->dev.parent); 91 92 gpio = devm_kzalloc(&pdev->dev, sizeof(*gpio), GFP_KERNEL); 93 if (!gpio) 94 return -ENOMEM; 95 96 gpio->regmap = a10sr->regmap; 97 98 gpio->gp = altr_a10sr_gc; 99 gpio->gp.parent = pdev->dev.parent; 100 gpio->gp.of_node = pdev->dev.of_node; 101 102 ret = devm_gpiochip_add_data(&pdev->dev, &gpio->gp, gpio); 103 if (ret < 0) { 104 dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret); 105 return ret; 106 } 107 108 platform_set_drvdata(pdev, gpio); 109 110 return 0; 111 } 112 113 static const struct of_device_id altr_a10sr_gpio_of_match[] = { 114 { .compatible = "altr,a10sr-gpio" }, 115 { }, 116 }; 117 MODULE_DEVICE_TABLE(of, altr_a10sr_gpio_of_match); 118 119 static struct platform_driver altr_a10sr_gpio_driver = { 120 .probe = altr_a10sr_gpio_probe, 121 .driver = { 122 .name = "altr_a10sr_gpio", 123 .of_match_table = of_match_ptr(altr_a10sr_gpio_of_match), 124 }, 125 }; 126 module_platform_driver(altr_a10sr_gpio_driver); 127 128 MODULE_LICENSE("GPL v2"); 129 MODULE_AUTHOR("Thor Thayer <tthayer@opensource.altera.com>"); 130 MODULE_DESCRIPTION("Altera Arria10 System Resource Chip GPIO"); 131